Merge tag 'drm-intel-next-fixes-2014-10-17' of git://anongit.freedesktop.org/drm...

[deliverable/linux.git] / arch / x86 / kvm / vmx.c

/*
 * Kernel-based Virtual Machine driver for Linux
 *
 * This module enables machines with Intel VT-x extensions to run virtual
 * machines without emulation or binary translation.
 *
 * Copyright (C) 2006 Qumranet, Inc.
 * Copyright 2010 Red Hat, Inc. and/or its affiliates.
 *
 * Authors:
 *   Avi Kivity   <avi@qumranet.com>
 *   Yaniv Kamay  <yaniv@qumranet.com>
 *
 * This work is licensed under the terms of the GNU GPL, version 2.  See
 * the COPYING file in the top-level directory.
 *
 */

#include "irq.h"
#include "mmu.h"
#include "cpuid.h"

#include <linux/kvm_host.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/highmem.h>
#include <linux/sched.h>
#include <linux/moduleparam.h>
#include <linux/mod_devicetable.h>
#include <linux/ftrace_event.h>
#include <linux/slab.h>
#include <linux/tboot.h>
#include <linux/hrtimer.h>
#include "kvm_cache_regs.h"
#include "x86.h"

#include <asm/io.h>
#include <asm/desc.h>
#include <asm/vmx.h>
#include <asm/virtext.h>
#include <asm/mce.h>
#include <asm/i387.h>
#include <asm/xcr.h>
#include <asm/perf_event.h>
#include <asm/debugreg.h>
#include <asm/kexec.h>

#include "trace.h"

#define __ex(x) __kvm_handle_fault_on_reboot(x)
#define __ex_clear(x, reg) \
        ____kvm_handle_fault_on_reboot(x, "xor " reg " , " reg)

MODULE_AUTHOR("Qumranet");
MODULE_LICENSE("GPL");

static const struct x86_cpu_id vmx_cpu_id[] = {
        X86_FEATURE_MATCH(X86_FEATURE_VMX),
        {}
};
MODULE_DEVICE_TABLE(x86cpu, vmx_cpu_id);

static bool __read_mostly enable_vpid = 1;
module_param_named(vpid, enable_vpid, bool, 0444);

static bool __read_mostly flexpriority_enabled = 1;
module_param_named(flexpriority, flexpriority_enabled, bool, S_IRUGO);

static bool __read_mostly enable_ept = 1;
module_param_named(ept, enable_ept, bool, S_IRUGO);

static bool __read_mostly enable_unrestricted_guest = 1;
module_param_named(unrestricted_guest,
                        enable_unrestricted_guest, bool, S_IRUGO);

static bool __read_mostly enable_ept_ad_bits = 1;
module_param_named(eptad, enable_ept_ad_bits, bool, S_IRUGO);

static bool __read_mostly emulate_invalid_guest_state = true;
module_param(emulate_invalid_guest_state, bool, S_IRUGO);

static bool __read_mostly vmm_exclusive = 1;
module_param(vmm_exclusive, bool, S_IRUGO);

static bool __read_mostly fasteoi = 1;
module_param(fasteoi, bool, S_IRUGO);

static bool __read_mostly enable_apicv = 1;
module_param(enable_apicv, bool, S_IRUGO);

static bool __read_mostly enable_shadow_vmcs = 1;
module_param_named(enable_shadow_vmcs, enable_shadow_vmcs, bool, S_IRUGO);
/*
 * If nested=1, nested virtualization is supported, i.e., guests may use
 * VMX and be a hypervisor for its own guests. If nested=0, guests may not
 * use VMX instructions.
 */
static bool __read_mostly nested = 0;
module_param(nested, bool, S_IRUGO);

#define KVM_GUEST_CR0_MASK (X86_CR0_NW | X86_CR0_CD)
#define KVM_VM_CR0_ALWAYS_ON_UNRESTRICTED_GUEST (X86_CR0_WP | X86_CR0_NE)
#define KVM_VM_CR0_ALWAYS_ON                                            \
        (KVM_VM_CR0_ALWAYS_ON_UNRESTRICTED_GUEST | X86_CR0_PG | X86_CR0_PE)
#define KVM_CR4_GUEST_OWNED_BITS                                      \
        (X86_CR4_PVI | X86_CR4_DE | X86_CR4_PCE | X86_CR4_OSFXSR      \
         | X86_CR4_OSXMMEXCPT)

#define KVM_PMODE_VM_CR4_ALWAYS_ON (X86_CR4_PAE | X86_CR4_VMXE)
#define KVM_RMODE_VM_CR4_ALWAYS_ON (X86_CR4_VME | X86_CR4_PAE | X86_CR4_VMXE)

#define RMODE_GUEST_OWNED_EFLAGS_BITS (~(X86_EFLAGS_IOPL | X86_EFLAGS_VM))

#define VMX_MISC_EMULATED_PREEMPTION_TIMER_RATE 5

/*
 * These 2 parameters are used to config the controls for Pause-Loop Exiting:
 * ple_gap:    upper bound on the amount of time between two successive
 *             executions of PAUSE in a loop. Also indicate if ple enabled.
 *             According to test, this time is usually smaller than 128 cycles.
 * ple_window: upper bound on the amount of time a guest is allowed to execute
 *             in a PAUSE loop. Tests indicate that most spinlocks are held for
 *             less than 2^12 cycles
 * Time is measured based on a counter that runs at the same rate as the TSC,
 * refer SDM volume 3b section 21.6.13 & 22.1.3.
 */
#define KVM_VMX_DEFAULT_PLE_GAP           128
#define KVM_VMX_DEFAULT_PLE_WINDOW        4096
#define KVM_VMX_DEFAULT_PLE_WINDOW_GROW   2
#define KVM_VMX_DEFAULT_PLE_WINDOW_SHRINK 0
#define KVM_VMX_DEFAULT_PLE_WINDOW_MAX    \
                INT_MAX / KVM_VMX_DEFAULT_PLE_WINDOW_GROW

static int ple_gap = KVM_VMX_DEFAULT_PLE_GAP;
module_param(ple_gap, int, S_IRUGO);

static int ple_window = KVM_VMX_DEFAULT_PLE_WINDOW;
module_param(ple_window, int, S_IRUGO);

/* Default doubles per-vcpu window every exit. */
static int ple_window_grow = KVM_VMX_DEFAULT_PLE_WINDOW_GROW;
module_param(ple_window_grow, int, S_IRUGO);

/* Default resets per-vcpu window every exit to ple_window. */
static int ple_window_shrink = KVM_VMX_DEFAULT_PLE_WINDOW_SHRINK;
module_param(ple_window_shrink, int, S_IRUGO);

/* Default is to compute the maximum so we can never overflow. */
static int ple_window_actual_max = KVM_VMX_DEFAULT_PLE_WINDOW_MAX;
static int ple_window_max        = KVM_VMX_DEFAULT_PLE_WINDOW_MAX;
module_param(ple_window_max, int, S_IRUGO);

extern const ulong vmx_return;

#define NR_AUTOLOAD_MSRS 8
#define VMCS02_POOL_SIZE 1

struct vmcs {
        u32 revision_id;
        u32 abort;
        char data[0];
};

/*
 * Track a VMCS that may be loaded on a certain CPU. If it is (cpu!=-1), also
 * remember whether it was VMLAUNCHed, and maintain a linked list of all VMCSs
 * loaded on this CPU (so we can clear them if the CPU goes down).
 */
struct loaded_vmcs {
        struct vmcs *vmcs;
        int cpu;
        int launched;
        struct list_head loaded_vmcss_on_cpu_link;
};

struct shared_msr_entry {
        unsigned index;
        u64 data;
        u64 mask;
};

/*
 * struct vmcs12 describes the state that our guest hypervisor (L1) keeps for a
 * single nested guest (L2), hence the name vmcs12. Any VMX implementation has
 * a VMCS structure, and vmcs12 is our emulated VMX's VMCS. This structure is
 * stored in guest memory specified by VMPTRLD, but is opaque to the guest,
 * which must access it using VMREAD/VMWRITE/VMCLEAR instructions.
 * More than one of these structures may exist, if L1 runs multiple L2 guests.
 * nested_vmx_run() will use the data here to build a vmcs02: a VMCS for the
 * underlying hardware which will be used to run L2.
 * This structure is packed to ensure that its layout is identical across
 * machines (necessary for live migration).
 * If there are changes in this struct, VMCS12_REVISION must be changed.
 */
typedef u64 natural_width;
struct __packed vmcs12 {
        /* According to the Intel spec, a VMCS region must start with the
         * following two fields. Then follow implementation-specific data.
         */
        u32 revision_id;
        u32 abort;

        u32 launch_state; /* set to 0 by VMCLEAR, to 1 by VMLAUNCH */
        u32 padding[7]; /* room for future expansion */

        u64 io_bitmap_a;
        u64 io_bitmap_b;
        u64 msr_bitmap;
        u64 vm_exit_msr_store_addr;
        u64 vm_exit_msr_load_addr;
        u64 vm_entry_msr_load_addr;
        u64 tsc_offset;
        u64 virtual_apic_page_addr;
        u64 apic_access_addr;
        u64 ept_pointer;
        u64 guest_physical_address;
        u64 vmcs_link_pointer;
        u64 guest_ia32_debugctl;
        u64 guest_ia32_pat;
        u64 guest_ia32_efer;
        u64 guest_ia32_perf_global_ctrl;
        u64 guest_pdptr0;
        u64 guest_pdptr1;
        u64 guest_pdptr2;
        u64 guest_pdptr3;
        u64 guest_bndcfgs;
        u64 host_ia32_pat;
        u64 host_ia32_efer;
        u64 host_ia32_perf_global_ctrl;
        u64 padding64[8]; /* room for future expansion */
        /*
         * To allow migration of L1 (complete with its L2 guests) between
         * machines of different natural widths (32 or 64 bit), we cannot have
         * unsigned long fields with no explict size. We use u64 (aliased
         * natural_width) instead. Luckily, x86 is little-endian.
         */
        natural_width cr0_guest_host_mask;
        natural_width cr4_guest_host_mask;
        natural_width cr0_read_shadow;
        natural_width cr4_read_shadow;
        natural_width cr3_target_value0;
        natural_width cr3_target_value1;
        natural_width cr3_target_value2;
        natural_width cr3_target_value3;
        natural_width exit_qualification;
        natural_width guest_linear_address;
        natural_width guest_cr0;
        natural_width guest_cr3;
        natural_width guest_cr4;
        natural_width guest_es_base;
        natural_width guest_cs_base;
        natural_width guest_ss_base;
        natural_width guest_ds_base;
        natural_width guest_fs_base;
        natural_width guest_gs_base;
        natural_width guest_ldtr_base;
        natural_width guest_tr_base;
        natural_width guest_gdtr_base;
        natural_width guest_idtr_base;
        natural_width guest_dr7;
        natural_width guest_rsp;
        natural_width guest_rip;
        natural_width guest_rflags;
        natural_width guest_pending_dbg_exceptions;
        natural_width guest_sysenter_esp;
        natural_width guest_sysenter_eip;
        natural_width host_cr0;
        natural_width host_cr3;
        natural_width host_cr4;
        natural_width host_fs_base;
        natural_width host_gs_base;
        natural_width host_tr_base;
        natural_width host_gdtr_base;
        natural_width host_idtr_base;
        natural_width host_ia32_sysenter_esp;
        natural_width host_ia32_sysenter_eip;
        natural_width host_rsp;
        natural_width host_rip;
        natural_width paddingl[8]; /* room for future expansion */
        u32 pin_based_vm_exec_control;
        u32 cpu_based_vm_exec_control;
        u32 exception_bitmap;
        u32 page_fault_error_code_mask;
        u32 page_fault_error_code_match;
        u32 cr3_target_count;
        u32 vm_exit_controls;
        u32 vm_exit_msr_store_count;
        u32 vm_exit_msr_load_count;
        u32 vm_entry_controls;
        u32 vm_entry_msr_load_count;
        u32 vm_entry_intr_info_field;
        u32 vm_entry_exception_error_code;
        u32 vm_entry_instruction_len;
        u32 tpr_threshold;
        u32 secondary_vm_exec_control;
        u32 vm_instruction_error;
        u32 vm_exit_reason;
        u32 vm_exit_intr_info;
        u32 vm_exit_intr_error_code;
        u32 idt_vectoring_info_field;
        u32 idt_vectoring_error_code;
        u32 vm_exit_instruction_len;
        u32 vmx_instruction_info;
        u32 guest_es_limit;
        u32 guest_cs_limit;
        u32 guest_ss_limit;
        u32 guest_ds_limit;
        u32 guest_fs_limit;
        u32 guest_gs_limit;
        u32 guest_ldtr_limit;
        u32 guest_tr_limit;
        u32 guest_gdtr_limit;
        u32 guest_idtr_limit;
        u32 guest_es_ar_bytes;
        u32 guest_cs_ar_bytes;
        u32 guest_ss_ar_bytes;
        u32 guest_ds_ar_bytes;
        u32 guest_fs_ar_bytes;
        u32 guest_gs_ar_bytes;
        u32 guest_ldtr_ar_bytes;
        u32 guest_tr_ar_bytes;
        u32 guest_interruptibility_info;
        u32 guest_activity_state;
        u32 guest_sysenter_cs;
        u32 host_ia32_sysenter_cs;
        u32 vmx_preemption_timer_value;
        u32 padding32[7]; /* room for future expansion */
        u16 virtual_processor_id;
        u16 guest_es_selector;
        u16 guest_cs_selector;
        u16 guest_ss_selector;
        u16 guest_ds_selector;
        u16 guest_fs_selector;
        u16 guest_gs_selector;
        u16 guest_ldtr_selector;
        u16 guest_tr_selector;
        u16 host_es_selector;
        u16 host_cs_selector;
        u16 host_ss_selector;
        u16 host_ds_selector;
        u16 host_fs_selector;
        u16 host_gs_selector;
        u16 host_tr_selector;
};

/*
 * VMCS12_REVISION is an arbitrary id that should be changed if the content or
 * layout of struct vmcs12 is changed. MSR_IA32_VMX_BASIC returns this id, and
 * VMPTRLD verifies that the VMCS region that L1 is loading contains this id.
 */
#define VMCS12_REVISION 0x11e57ed0

/*
 * VMCS12_SIZE is the number of bytes L1 should allocate for the VMXON region
 * and any VMCS region. Although only sizeof(struct vmcs12) are used by the
 * current implementation, 4K are reserved to avoid future complications.
 */
#define VMCS12_SIZE 0x1000

/* Used to remember the last vmcs02 used for some recently used vmcs12s */
struct vmcs02_list {
        struct list_head list;
        gpa_t vmptr;
        struct loaded_vmcs vmcs02;
};

/*
 * The nested_vmx structure is part of vcpu_vmx, and holds information we need
 * for correct emulation of VMX (i.e., nested VMX) on this vcpu.
 */
struct nested_vmx {
        /* Has the level1 guest done vmxon? */
        bool vmxon;
        gpa_t vmxon_ptr;

        /* The guest-physical address of the current VMCS L1 keeps for L2 */
        gpa_t current_vmptr;
        /* The host-usable pointer to the above */
        struct page *current_vmcs12_page;
        struct vmcs12 *current_vmcs12;
        struct vmcs *current_shadow_vmcs;
        /*
         * Indicates if the shadow vmcs must be updated with the
         * data hold by vmcs12
         */
        bool sync_shadow_vmcs;

        /* vmcs02_list cache of VMCSs recently used to run L2 guests */
        struct list_head vmcs02_pool;
        int vmcs02_num;
        u64 vmcs01_tsc_offset;
        /* L2 must run next, and mustn't decide to exit to L1. */
        bool nested_run_pending;
        /*
         * Guest pages referred to in vmcs02 with host-physical pointers, so
         * we must keep them pinned while L2 runs.
         */
        struct page *apic_access_page;
        struct page *virtual_apic_page;
        u64 msr_ia32_feature_control;

        struct hrtimer preemption_timer;
        bool preemption_timer_expired;

        /* to migrate it to L2 if VM_ENTRY_LOAD_DEBUG_CONTROLS is off */
        u64 vmcs01_debugctl;
};

#define POSTED_INTR_ON  0
/* Posted-Interrupt Descriptor */
struct pi_desc {
        u32 pir[8];     /* Posted interrupt requested */
        u32 control;    /* bit 0 of control is outstanding notification bit */
        u32 rsvd[7];
} __aligned(64);

static bool pi_test_and_set_on(struct pi_desc *pi_desc)
{
        return test_and_set_bit(POSTED_INTR_ON,
                        (unsigned long *)&pi_desc->control);
}

static bool pi_test_and_clear_on(struct pi_desc *pi_desc)
{
        return test_and_clear_bit(POSTED_INTR_ON,
                        (unsigned long *)&pi_desc->control);
}

static int pi_test_and_set_pir(int vector, struct pi_desc *pi_desc)
{
        return test_and_set_bit(vector, (unsigned long *)pi_desc->pir);
}

struct vcpu_vmx {
        struct kvm_vcpu       vcpu;
        unsigned long         host_rsp;
        u8                    fail;
        bool                  nmi_known_unmasked;
        u32                   exit_intr_info;
        u32                   idt_vectoring_info;
        ulong                 rflags;
        struct shared_msr_entry *guest_msrs;
        int                   nmsrs;
        int                   save_nmsrs;
        unsigned long         host_idt_base;
#ifdef CONFIG_X86_64
        u64                   msr_host_kernel_gs_base;
        u64                   msr_guest_kernel_gs_base;
#endif
        u32 vm_entry_controls_shadow;
        u32 vm_exit_controls_shadow;
        /*
         * loaded_vmcs points to the VMCS currently used in this vcpu. For a
         * non-nested (L1) guest, it always points to vmcs01. For a nested
         * guest (L2), it points to a different VMCS.
         */
        struct loaded_vmcs    vmcs01;
        struct loaded_vmcs   *loaded_vmcs;
        bool                  __launched; /* temporary, used in vmx_vcpu_run */
        struct msr_autoload {
                unsigned nr;
                struct vmx_msr_entry guest[NR_AUTOLOAD_MSRS];
                struct vmx_msr_entry host[NR_AUTOLOAD_MSRS];
        } msr_autoload;
        struct {
                int           loaded;
                u16           fs_sel, gs_sel, ldt_sel;
#ifdef CONFIG_X86_64
                u16           ds_sel, es_sel;
#endif
                int           gs_ldt_reload_needed;
                int           fs_reload_needed;
                u64           msr_host_bndcfgs;
                unsigned long vmcs_host_cr4;    /* May not match real cr4 */
        } host_state;
        struct {
                int vm86_active;
                ulong save_rflags;
                struct kvm_segment segs[8];
        } rmode;
        struct {
                u32 bitmask; /* 4 bits per segment (1 bit per field) */
                struct kvm_save_segment {
                        u16 selector;
                        unsigned long base;
                        u32 limit;
                        u32 ar;
                } seg[8];
        } segment_cache;
        int vpid;
        bool emulation_required;

        /* Support for vnmi-less CPUs */
        int soft_vnmi_blocked;
        ktime_t entry_time;
        s64 vnmi_blocked_time;
        u32 exit_reason;

        bool rdtscp_enabled;

        /* Posted interrupt descriptor */
        struct pi_desc pi_desc;

        /* Support for a guest hypervisor (nested VMX) */
        struct nested_vmx nested;

        /* Dynamic PLE window. */
        int ple_window;
        bool ple_window_dirty;
};

enum segment_cache_field {
        SEG_FIELD_SEL = 0,
        SEG_FIELD_BASE = 1,
        SEG_FIELD_LIMIT = 2,
        SEG_FIELD_AR = 3,

        SEG_FIELD_NR = 4
};

static inline struct vcpu_vmx *to_vmx(struct kvm_vcpu *vcpu)
{
        return container_of(vcpu, struct vcpu_vmx, vcpu);
}

#define VMCS12_OFFSET(x) offsetof(struct vmcs12, x)
#define FIELD(number, name)     [number] = VMCS12_OFFSET(name)
#define FIELD64(number, name)   [number] = VMCS12_OFFSET(name), \
                                [number##_HIGH] = VMCS12_OFFSET(name)+4


static unsigned long shadow_read_only_fields[] = {
        /*
         * We do NOT shadow fields that are modified when L0
         * traps and emulates any vmx instruction (e.g. VMPTRLD,
         * VMXON...) executed by L1.
         * For example, VM_INSTRUCTION_ERROR is read
         * by L1 if a vmx instruction fails (part of the error path).
         * Note the code assumes this logic. If for some reason
         * we start shadowing these fields then we need to
         * force a shadow sync when L0 emulates vmx instructions
         * (e.g. force a sync if VM_INSTRUCTION_ERROR is modified
         * by nested_vmx_failValid)
         */
        VM_EXIT_REASON,
        VM_EXIT_INTR_INFO,
        VM_EXIT_INSTRUCTION_LEN,
        IDT_VECTORING_INFO_FIELD,
        IDT_VECTORING_ERROR_CODE,
        VM_EXIT_INTR_ERROR_CODE,
        EXIT_QUALIFICATION,
        GUEST_LINEAR_ADDRESS,
        GUEST_PHYSICAL_ADDRESS
};
static int max_shadow_read_only_fields =
        ARRAY_SIZE(shadow_read_only_fields);

static unsigned long shadow_read_write_fields[] = {
        TPR_THRESHOLD,
        GUEST_RIP,
        GUEST_RSP,
        GUEST_CR0,
        GUEST_CR3,
        GUEST_CR4,
        GUEST_INTERRUPTIBILITY_INFO,
        GUEST_RFLAGS,
        GUEST_CS_SELECTOR,
        GUEST_CS_AR_BYTES,
        GUEST_CS_LIMIT,
        GUEST_CS_BASE,
        GUEST_ES_BASE,
        GUEST_BNDCFGS,
        CR0_GUEST_HOST_MASK,
        CR0_READ_SHADOW,
        CR4_READ_SHADOW,
        TSC_OFFSET,
        EXCEPTION_BITMAP,
        CPU_BASED_VM_EXEC_CONTROL,
        VM_ENTRY_EXCEPTION_ERROR_CODE,
        VM_ENTRY_INTR_INFO_FIELD,
        VM_ENTRY_INSTRUCTION_LEN,
        VM_ENTRY_EXCEPTION_ERROR_CODE,
        HOST_FS_BASE,
        HOST_GS_BASE,
        HOST_FS_SELECTOR,
        HOST_GS_SELECTOR
};
static int max_shadow_read_write_fields =
        ARRAY_SIZE(shadow_read_write_fields);

static const unsigned short vmcs_field_to_offset_table[] = {
        FIELD(VIRTUAL_PROCESSOR_ID, virtual_processor_id),
        FIELD(GUEST_ES_SELECTOR, guest_es_selector),
        FIELD(GUEST_CS_SELECTOR, guest_cs_selector),
        FIELD(GUEST_SS_SELECTOR, guest_ss_selector),
        FIELD(GUEST_DS_SELECTOR, guest_ds_selector),
        FIELD(GUEST_FS_SELECTOR, guest_fs_selector),
        FIELD(GUEST_GS_SELECTOR, guest_gs_selector),
        FIELD(GUEST_LDTR_SELECTOR, guest_ldtr_selector),
        FIELD(GUEST_TR_SELECTOR, guest_tr_selector),
        FIELD(HOST_ES_SELECTOR, host_es_selector),
        FIELD(HOST_CS_SELECTOR, host_cs_selector),
        FIELD(HOST_SS_SELECTOR, host_ss_selector),
        FIELD(HOST_DS_SELECTOR, host_ds_selector),
        FIELD(HOST_FS_SELECTOR, host_fs_selector),
        FIELD(HOST_GS_SELECTOR, host_gs_selector),
        FIELD(HOST_TR_SELECTOR, host_tr_selector),
        FIELD64(IO_BITMAP_A, io_bitmap_a),
        FIELD64(IO_BITMAP_B, io_bitmap_b),
        FIELD64(MSR_BITMAP, msr_bitmap),
        FIELD64(VM_EXIT_MSR_STORE_ADDR, vm_exit_msr_store_addr),
        FIELD64(VM_EXIT_MSR_LOAD_ADDR, vm_exit_msr_load_addr),
        FIELD64(VM_ENTRY_MSR_LOAD_ADDR, vm_entry_msr_load_addr),
        FIELD64(TSC_OFFSET, tsc_offset),
        FIELD64(VIRTUAL_APIC_PAGE_ADDR, virtual_apic_page_addr),
        FIELD64(APIC_ACCESS_ADDR, apic_access_addr),
        FIELD64(EPT_POINTER, ept_pointer),
        FIELD64(GUEST_PHYSICAL_ADDRESS, guest_physical_address),
        FIELD64(VMCS_LINK_POINTER, vmcs_link_pointer),
        FIELD64(GUEST_IA32_DEBUGCTL, guest_ia32_debugctl),
        FIELD64(GUEST_IA32_PAT, guest_ia32_pat),
        FIELD64(GUEST_IA32_EFER, guest_ia32_efer),
        FIELD64(GUEST_IA32_PERF_GLOBAL_CTRL, guest_ia32_perf_global_ctrl),
        FIELD64(GUEST_PDPTR0, guest_pdptr0),
        FIELD64(GUEST_PDPTR1, guest_pdptr1),
        FIELD64(GUEST_PDPTR2, guest_pdptr2),
        FIELD64(GUEST_PDPTR3, guest_pdptr3),
        FIELD64(GUEST_BNDCFGS, guest_bndcfgs),
        FIELD64(HOST_IA32_PAT, host_ia32_pat),
        FIELD64(HOST_IA32_EFER, host_ia32_efer),
        FIELD64(HOST_IA32_PERF_GLOBAL_CTRL, host_ia32_perf_global_ctrl),
        FIELD(PIN_BASED_VM_EXEC_CONTROL, pin_based_vm_exec_control),
        FIELD(CPU_BASED_VM_EXEC_CONTROL, cpu_based_vm_exec_control),
        FIELD(EXCEPTION_BITMAP, exception_bitmap),
        FIELD(PAGE_FAULT_ERROR_CODE_MASK, page_fault_error_code_mask),
        FIELD(PAGE_FAULT_ERROR_CODE_MATCH, page_fault_error_code_match),
        FIELD(CR3_TARGET_COUNT, cr3_target_count),
        FIELD(VM_EXIT_CONTROLS, vm_exit_controls),
        FIELD(VM_EXIT_MSR_STORE_COUNT, vm_exit_msr_store_count),
        FIELD(VM_EXIT_MSR_LOAD_COUNT, vm_exit_msr_load_count),
        FIELD(VM_ENTRY_CONTROLS, vm_entry_controls),
        FIELD(VM_ENTRY_MSR_LOAD_COUNT, vm_entry_msr_load_count),
        FIELD(VM_ENTRY_INTR_INFO_FIELD, vm_entry_intr_info_field),
        FIELD(VM_ENTRY_EXCEPTION_ERROR_CODE, vm_entry_exception_error_code),
        FIELD(VM_ENTRY_INSTRUCTION_LEN, vm_entry_instruction_len),
        FIELD(TPR_THRESHOLD, tpr_threshold),
        FIELD(SECONDARY_VM_EXEC_CONTROL, secondary_vm_exec_control),
        FIELD(VM_INSTRUCTION_ERROR, vm_instruction_error),
        FIELD(VM_EXIT_REASON, vm_exit_reason),
        FIELD(VM_EXIT_INTR_INFO, vm_exit_intr_info),
        FIELD(VM_EXIT_INTR_ERROR_CODE, vm_exit_intr_error_code),
        FIELD(IDT_VECTORING_INFO_FIELD, idt_vectoring_info_field),
        FIELD(IDT_VECTORING_ERROR_CODE, idt_vectoring_error_code),
        FIELD(VM_EXIT_INSTRUCTION_LEN, vm_exit_instruction_len),
        FIELD(VMX_INSTRUCTION_INFO, vmx_instruction_info),
        FIELD(GUEST_ES_LIMIT, guest_es_limit),
        FIELD(GUEST_CS_LIMIT, guest_cs_limit),
        FIELD(GUEST_SS_LIMIT, guest_ss_limit),
        FIELD(GUEST_DS_LIMIT, guest_ds_limit),
        FIELD(GUEST_FS_LIMIT, guest_fs_limit),
        FIELD(GUEST_GS_LIMIT, guest_gs_limit),
        FIELD(GUEST_LDTR_LIMIT, guest_ldtr_limit),
        FIELD(GUEST_TR_LIMIT, guest_tr_limit),
        FIELD(GUEST_GDTR_LIMIT, guest_gdtr_limit),
        FIELD(GUEST_IDTR_LIMIT, guest_idtr_limit),
        FIELD(GUEST_ES_AR_BYTES, guest_es_ar_bytes),
        FIELD(GUEST_CS_AR_BYTES, guest_cs_ar_bytes),
        FIELD(GUEST_SS_AR_BYTES, guest_ss_ar_bytes),
        FIELD(GUEST_DS_AR_BYTES, guest_ds_ar_bytes),
        FIELD(GUEST_FS_AR_BYTES, guest_fs_ar_bytes),
        FIELD(GUEST_GS_AR_BYTES, guest_gs_ar_bytes),
        FIELD(GUEST_LDTR_AR_BYTES, guest_ldtr_ar_bytes),
        FIELD(GUEST_TR_AR_BYTES, guest_tr_ar_bytes),
        FIELD(GUEST_INTERRUPTIBILITY_INFO, guest_interruptibility_info),
        FIELD(GUEST_ACTIVITY_STATE, guest_activity_state),
        FIELD(GUEST_SYSENTER_CS, guest_sysenter_cs),
        FIELD(HOST_IA32_SYSENTER_CS, host_ia32_sysenter_cs),
        FIELD(VMX_PREEMPTION_TIMER_VALUE, vmx_preemption_timer_value),
        FIELD(CR0_GUEST_HOST_MASK, cr0_guest_host_mask),
        FIELD(CR4_GUEST_HOST_MASK, cr4_guest_host_mask),
        FIELD(CR0_READ_SHADOW, cr0_read_shadow),
        FIELD(CR4_READ_SHADOW, cr4_read_shadow),
        FIELD(CR3_TARGET_VALUE0, cr3_target_value0),
        FIELD(CR3_TARGET_VALUE1, cr3_target_value1),
        FIELD(CR3_TARGET_VALUE2, cr3_target_value2),
        FIELD(CR3_TARGET_VALUE3, cr3_target_value3),
        FIELD(EXIT_QUALIFICATION, exit_qualification),
        FIELD(GUEST_LINEAR_ADDRESS, guest_linear_address),
        FIELD(GUEST_CR0, guest_cr0),
        FIELD(GUEST_CR3, guest_cr3),
        FIELD(GUEST_CR4, guest_cr4),
        FIELD(GUEST_ES_BASE, guest_es_base),
        FIELD(GUEST_CS_BASE, guest_cs_base),
        FIELD(GUEST_SS_BASE, guest_ss_base),
        FIELD(GUEST_DS_BASE, guest_ds_base),
        FIELD(GUEST_FS_BASE, guest_fs_base),
        FIELD(GUEST_GS_BASE, guest_gs_base),
        FIELD(GUEST_LDTR_BASE, guest_ldtr_base),
        FIELD(GUEST_TR_BASE, guest_tr_base),
        FIELD(GUEST_GDTR_BASE, guest_gdtr_base),
        FIELD(GUEST_IDTR_BASE, guest_idtr_base),
        FIELD(GUEST_DR7, guest_dr7),
        FIELD(GUEST_RSP, guest_rsp),
        FIELD(GUEST_RIP, guest_rip),
        FIELD(GUEST_RFLAGS, guest_rflags),
        FIELD(GUEST_PENDING_DBG_EXCEPTIONS, guest_pending_dbg_exceptions),
        FIELD(GUEST_SYSENTER_ESP, guest_sysenter_esp),
        FIELD(GUEST_SYSENTER_EIP, guest_sysenter_eip),
        FIELD(HOST_CR0, host_cr0),
        FIELD(HOST_CR3, host_cr3),
        FIELD(HOST_CR4, host_cr4),
        FIELD(HOST_FS_BASE, host_fs_base),
        FIELD(HOST_GS_BASE, host_gs_base),
        FIELD(HOST_TR_BASE, host_tr_base),
        FIELD(HOST_GDTR_BASE, host_gdtr_base),
        FIELD(HOST_IDTR_BASE, host_idtr_base),
        FIELD(HOST_IA32_SYSENTER_ESP, host_ia32_sysenter_esp),
        FIELD(HOST_IA32_SYSENTER_EIP, host_ia32_sysenter_eip),
        FIELD(HOST_RSP, host_rsp),
        FIELD(HOST_RIP, host_rip),
};
static const int max_vmcs_field = ARRAY_SIZE(vmcs_field_to_offset_table);

static inline short vmcs_field_to_offset(unsigned long field)
{
        if (field >= max_vmcs_field || vmcs_field_to_offset_table[field] == 0)
                return -1;
        return vmcs_field_to_offset_table[field];
}

static inline struct vmcs12 *get_vmcs12(struct kvm_vcpu *vcpu)
{
        return to_vmx(vcpu)->nested.current_vmcs12;
}

static struct page *nested_get_page(struct kvm_vcpu *vcpu, gpa_t addr)
{
        struct page *page = gfn_to_page(vcpu->kvm, addr >> PAGE_SHIFT);
        if (is_error_page(page))
                return NULL;

        return page;
}

static void nested_release_page(struct page *page)
{
        kvm_release_page_dirty(page);
}

static void nested_release_page_clean(struct page *page)
{
        kvm_release_page_clean(page);
}

static unsigned long nested_ept_get_cr3(struct kvm_vcpu *vcpu);
static u64 construct_eptp(unsigned long root_hpa);
static void kvm_cpu_vmxon(u64 addr);
static void kvm_cpu_vmxoff(void);
static bool vmx_mpx_supported(void);
static int vmx_set_tss_addr(struct kvm *kvm, unsigned int addr);
static void vmx_set_segment(struct kvm_vcpu *vcpu,
                            struct kvm_segment *var, int seg);
static void vmx_get_segment(struct kvm_vcpu *vcpu,
                            struct kvm_segment *var, int seg);
static bool guest_state_valid(struct kvm_vcpu *vcpu);
static u32 vmx_segment_access_rights(struct kvm_segment *var);
static void vmx_sync_pir_to_irr_dummy(struct kvm_vcpu *vcpu);
static void copy_vmcs12_to_shadow(struct vcpu_vmx *vmx);
static void copy_shadow_to_vmcs12(struct vcpu_vmx *vmx);
static int alloc_identity_pagetable(struct kvm *kvm);

static DEFINE_PER_CPU(struct vmcs *, vmxarea);
static DEFINE_PER_CPU(struct vmcs *, current_vmcs);
/*
 * We maintain a per-CPU linked-list of VMCS loaded on that CPU. This is needed
 * when a CPU is brought down, and we need to VMCLEAR all VMCSs loaded on it.
 */
static DEFINE_PER_CPU(struct list_head, loaded_vmcss_on_cpu);
static DEFINE_PER_CPU(struct desc_ptr, host_gdt);

static unsigned long *vmx_io_bitmap_a;
static unsigned long *vmx_io_bitmap_b;
static unsigned long *vmx_msr_bitmap_legacy;
static unsigned long *vmx_msr_bitmap_longmode;
static unsigned long *vmx_msr_bitmap_legacy_x2apic;
static unsigned long *vmx_msr_bitmap_longmode_x2apic;
static unsigned long *vmx_vmread_bitmap;
static unsigned long *vmx_vmwrite_bitmap;

static bool cpu_has_load_ia32_efer;
static bool cpu_has_load_perf_global_ctrl;

static DECLARE_BITMAP(vmx_vpid_bitmap, VMX_NR_VPIDS);
static DEFINE_SPINLOCK(vmx_vpid_lock);

static struct vmcs_config {
        int size;
        int order;
        u32 revision_id;
        u32 pin_based_exec_ctrl;
        u32 cpu_based_exec_ctrl;
        u32 cpu_based_2nd_exec_ctrl;
        u32 vmexit_ctrl;
        u32 vmentry_ctrl;
} vmcs_config;

static struct vmx_capability {
        u32 ept;
        u32 vpid;
} vmx_capability;

#define VMX_SEGMENT_FIELD(seg)                                  \
        [VCPU_SREG_##seg] = {                                   \
                .selector = GUEST_##seg##_SELECTOR,             \
                .base = GUEST_##seg##_BASE,                     \
                .limit = GUEST_##seg##_LIMIT,                   \
                .ar_bytes = GUEST_##seg##_AR_BYTES,             \
        }

static const struct kvm_vmx_segment_field {
        unsigned selector;
        unsigned base;
        unsigned limit;
        unsigned ar_bytes;
} kvm_vmx_segment_fields[] = {
        VMX_SEGMENT_FIELD(CS),
        VMX_SEGMENT_FIELD(DS),
        VMX_SEGMENT_FIELD(ES),
        VMX_SEGMENT_FIELD(FS),
        VMX_SEGMENT_FIELD(GS),
        VMX_SEGMENT_FIELD(SS),
        VMX_SEGMENT_FIELD(TR),
        VMX_SEGMENT_FIELD(LDTR),
};

static u64 host_efer;

static void ept_save_pdptrs(struct kvm_vcpu *vcpu);

/*
 * Keep MSR_STAR at the end, as setup_msrs() will try to optimize it
 * away by decrementing the array size.
 */
static const u32 vmx_msr_index[] = {
#ifdef CONFIG_X86_64
        MSR_SYSCALL_MASK, MSR_LSTAR, MSR_CSTAR,
#endif
        MSR_EFER, MSR_TSC_AUX, MSR_STAR,
};

static inline bool is_page_fault(u32 intr_info)
{
        return (intr_info & (INTR_INFO_INTR_TYPE_MASK | INTR_INFO_VECTOR_MASK |
                             INTR_INFO_VALID_MASK)) ==
                (INTR_TYPE_HARD_EXCEPTION | PF_VECTOR | INTR_INFO_VALID_MASK);
}

static inline bool is_no_device(u32 intr_info)
{
        return (intr_info & (INTR_INFO_INTR_TYPE_MASK | INTR_INFO_VECTOR_MASK |
                             INTR_INFO_VALID_MASK)) ==
                (INTR_TYPE_HARD_EXCEPTION | NM_VECTOR | INTR_INFO_VALID_MASK);
}

static inline bool is_invalid_opcode(u32 intr_info)
{
        return (intr_info & (INTR_INFO_INTR_TYPE_MASK | INTR_INFO_VECTOR_MASK |
                             INTR_INFO_VALID_MASK)) ==
                (INTR_TYPE_HARD_EXCEPTION | UD_VECTOR | INTR_INFO_VALID_MASK);
}

static inline bool is_external_interrupt(u32 intr_info)
{
        return (intr_info & (INTR_INFO_INTR_TYPE_MASK | INTR_INFO_VALID_MASK))
                == (INTR_TYPE_EXT_INTR | INTR_INFO_VALID_MASK);
}

static inline bool is_machine_check(u32 intr_info)
{
        return (intr_info & (INTR_INFO_INTR_TYPE_MASK | INTR_INFO_VECTOR_MASK |
                             INTR_INFO_VALID_MASK)) ==
                (INTR_TYPE_HARD_EXCEPTION | MC_VECTOR | INTR_INFO_VALID_MASK);
}

static inline bool cpu_has_vmx_msr_bitmap(void)
{
        return vmcs_config.cpu_based_exec_ctrl & CPU_BASED_USE_MSR_BITMAPS;
}

static inline bool cpu_has_vmx_tpr_shadow(void)
{
        return vmcs_config.cpu_based_exec_ctrl & CPU_BASED_TPR_SHADOW;
}

static inline bool vm_need_tpr_shadow(struct kvm *kvm)
{
        return (cpu_has_vmx_tpr_shadow()) && (irqchip_in_kernel(kvm));
}

static inline bool cpu_has_secondary_exec_ctrls(void)
{
        return vmcs_config.cpu_based_exec_ctrl &
                CPU_BASED_ACTIVATE_SECONDARY_CONTROLS;
}

static inline bool cpu_has_vmx_virtualize_apic_accesses(void)
{
        return vmcs_config.cpu_based_2nd_exec_ctrl &
                SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES;
}

static inline bool cpu_has_vmx_virtualize_x2apic_mode(void)
{
        return vmcs_config.cpu_based_2nd_exec_ctrl &
                SECONDARY_EXEC_VIRTUALIZE_X2APIC_MODE;
}

static inline bool cpu_has_vmx_apic_register_virt(void)
{
        return vmcs_config.cpu_based_2nd_exec_ctrl &
                SECONDARY_EXEC_APIC_REGISTER_VIRT;
}

static inline bool cpu_has_vmx_virtual_intr_delivery(void)
{
        return vmcs_config.cpu_based_2nd_exec_ctrl &
                SECONDARY_EXEC_VIRTUAL_INTR_DELIVERY;
}

static inline bool cpu_has_vmx_posted_intr(void)
{
        return vmcs_config.pin_based_exec_ctrl & PIN_BASED_POSTED_INTR;
}

static inline bool cpu_has_vmx_apicv(void)
{
        return cpu_has_vmx_apic_register_virt() &&
                cpu_has_vmx_virtual_intr_delivery() &&
                cpu_has_vmx_posted_intr();
}

static inline bool cpu_has_vmx_flexpriority(void)
{
        return cpu_has_vmx_tpr_shadow() &&
                cpu_has_vmx_virtualize_apic_accesses();
}

static inline bool cpu_has_vmx_ept_execute_only(void)
{
        return vmx_capability.ept & VMX_EPT_EXECUTE_ONLY_BIT;
}

static inline bool cpu_has_vmx_eptp_uncacheable(void)
{
        return vmx_capability.ept & VMX_EPTP_UC_BIT;
}

static inline bool cpu_has_vmx_eptp_writeback(void)
{
        return vmx_capability.ept & VMX_EPTP_WB_BIT;
}

static inline bool cpu_has_vmx_ept_2m_page(void)
{
        return vmx_capability.ept & VMX_EPT_2MB_PAGE_BIT;
}

static inline bool cpu_has_vmx_ept_1g_page(void)
{
        return vmx_capability.ept & VMX_EPT_1GB_PAGE_BIT;
}

static inline bool cpu_has_vmx_ept_4levels(void)
{
        return vmx_capability.ept & VMX_EPT_PAGE_WALK_4_BIT;
}

static inline bool cpu_has_vmx_ept_ad_bits(void)
{
        return vmx_capability.ept & VMX_EPT_AD_BIT;
}

static inline bool cpu_has_vmx_invept_context(void)
{
        return vmx_capability.ept & VMX_EPT_EXTENT_CONTEXT_BIT;
}

static inline bool cpu_has_vmx_invept_global(void)
{
        return vmx_capability.ept & VMX_EPT_EXTENT_GLOBAL_BIT;
}

static inline bool cpu_has_vmx_invvpid_single(void)
{
        return vmx_capability.vpid & VMX_VPID_EXTENT_SINGLE_CONTEXT_BIT;
}

static inline bool cpu_has_vmx_invvpid_global(void)
{
        return vmx_capability.vpid & VMX_VPID_EXTENT_GLOBAL_CONTEXT_BIT;
}

static inline bool cpu_has_vmx_ept(void)
{
        return vmcs_config.cpu_based_2nd_exec_ctrl &
                SECONDARY_EXEC_ENABLE_EPT;
}

static inline bool cpu_has_vmx_unrestricted_guest(void)
{
        return vmcs_config.cpu_based_2nd_exec_ctrl &
                SECONDARY_EXEC_UNRESTRICTED_GUEST;
}

static inline bool cpu_has_vmx_ple(void)
{
        return vmcs_config.cpu_based_2nd_exec_ctrl &
                SECONDARY_EXEC_PAUSE_LOOP_EXITING;
}

static inline bool vm_need_virtualize_apic_accesses(struct kvm *kvm)
{
        return flexpriority_enabled && irqchip_in_kernel(kvm);
}

static inline bool cpu_has_vmx_vpid(void)
{
        return vmcs_config.cpu_based_2nd_exec_ctrl &
                SECONDARY_EXEC_ENABLE_VPID;
}

static inline bool cpu_has_vmx_rdtscp(void)
{
        return vmcs_config.cpu_based_2nd_exec_ctrl &
                SECONDARY_EXEC_RDTSCP;
}

static inline bool cpu_has_vmx_invpcid(void)
{
        return vmcs_config.cpu_based_2nd_exec_ctrl &
                SECONDARY_EXEC_ENABLE_INVPCID;
}

static inline bool cpu_has_virtual_nmis(void)
{
        return vmcs_config.pin_based_exec_ctrl & PIN_BASED_VIRTUAL_NMIS;
}

static inline bool cpu_has_vmx_wbinvd_exit(void)
{
        return vmcs_config.cpu_based_2nd_exec_ctrl &
                SECONDARY_EXEC_WBINVD_EXITING;
}

static inline bool cpu_has_vmx_shadow_vmcs(void)
{
        u64 vmx_msr;
        rdmsrl(MSR_IA32_VMX_MISC, vmx_msr);
        /* check if the cpu supports writing r/o exit information fields */
        if (!(vmx_msr & MSR_IA32_VMX_MISC_VMWRITE_SHADOW_RO_FIELDS))
                return false;

        return vmcs_config.cpu_based_2nd_exec_ctrl &
                SECONDARY_EXEC_SHADOW_VMCS;
}

static inline bool report_flexpriority(void)
{
        return flexpriority_enabled;
}

static inline bool nested_cpu_has(struct vmcs12 *vmcs12, u32 bit)
{
        return vmcs12->cpu_based_vm_exec_control & bit;
}

static inline bool nested_cpu_has2(struct vmcs12 *vmcs12, u32 bit)
{
        return (vmcs12->cpu_based_vm_exec_control &
                        CPU_BASED_ACTIVATE_SECONDARY_CONTROLS) &&
                (vmcs12->secondary_vm_exec_control & bit);
}

static inline bool nested_cpu_has_virtual_nmis(struct vmcs12 *vmcs12)
{
        return vmcs12->pin_based_vm_exec_control & PIN_BASED_VIRTUAL_NMIS;
}

static inline bool nested_cpu_has_preemption_timer(struct vmcs12 *vmcs12)
{
        return vmcs12->pin_based_vm_exec_control &
                PIN_BASED_VMX_PREEMPTION_TIMER;
}

static inline int nested_cpu_has_ept(struct vmcs12 *vmcs12)
{
        return nested_cpu_has2(vmcs12, SECONDARY_EXEC_ENABLE_EPT);
}

static inline bool is_exception(u32 intr_info)
{
        return (intr_info & (INTR_INFO_INTR_TYPE_MASK | INTR_INFO_VALID_MASK))
                == (INTR_TYPE_HARD_EXCEPTION | INTR_INFO_VALID_MASK);
}

static void nested_vmx_vmexit(struct kvm_vcpu *vcpu, u32 exit_reason,
                              u32 exit_intr_info,
                              unsigned long exit_qualification);
static void nested_vmx_entry_failure(struct kvm_vcpu *vcpu,
                        struct vmcs12 *vmcs12,
                        u32 reason, unsigned long qualification);

static int __find_msr_index(struct vcpu_vmx *vmx, u32 msr)
{
        int i;

        for (i = 0; i < vmx->nmsrs; ++i)
                if (vmx_msr_index[vmx->guest_msrs[i].index] == msr)
                        return i;
        return -1;
}

static inline void __invvpid(int ext, u16 vpid, gva_t gva)
{
    struct {
        u64 vpid : 16;
        u64 rsvd : 48;
        u64 gva;
    } operand = { vpid, 0, gva };

    asm volatile (__ex(ASM_VMX_INVVPID)
                  /* CF==1 or ZF==1 --> rc = -1 */
                  "; ja 1f ; ud2 ; 1:"
                  : : "a"(&operand), "c"(ext) : "cc", "memory");
}

static inline void __invept(int ext, u64 eptp, gpa_t gpa)
{
        struct {
                u64 eptp, gpa;
        } operand = {eptp, gpa};

        asm volatile (__ex(ASM_VMX_INVEPT)
                        /* CF==1 or ZF==1 --> rc = -1 */
                        "; ja 1f ; ud2 ; 1:\n"
                        : : "a" (&operand), "c" (ext) : "cc", "memory");
}

static struct shared_msr_entry *find_msr_entry(struct vcpu_vmx *vmx, u32 msr)
{
        int i;

        i = __find_msr_index(vmx, msr);
        if (i >= 0)
                return &vmx->guest_msrs[i];
        return NULL;
}

static void vmcs_clear(struct vmcs *vmcs)
{
        u64 phys_addr = __pa(vmcs);
        u8 error;

        asm volatile (__ex(ASM_VMX_VMCLEAR_RAX) "; setna %0"
                      : "=qm"(error) : "a"(&phys_addr), "m"(phys_addr)
                      : "cc", "memory");
        if (error)
                printk(KERN_ERR "kvm: vmclear fail: %p/%llx\n",
                       vmcs, phys_addr);
}

static inline void loaded_vmcs_init(struct loaded_vmcs *loaded_vmcs)
{
        vmcs_clear(loaded_vmcs->vmcs);
        loaded_vmcs->cpu = -1;
        loaded_vmcs->launched = 0;
}

static void vmcs_load(struct vmcs *vmcs)
{
        u64 phys_addr = __pa(vmcs);
        u8 error;

        asm volatile (__ex(ASM_VMX_VMPTRLD_RAX) "; setna %0"
                        : "=qm"(error) : "a"(&phys_addr), "m"(phys_addr)
                        : "cc", "memory");
        if (error)
                printk(KERN_ERR "kvm: vmptrld %p/%llx failed\n",
                       vmcs, phys_addr);
}

#ifdef CONFIG_KEXEC
/*
 * This bitmap is used to indicate whether the vmclear
 * operation is enabled on all cpus. All disabled by
 * default.
 */
static cpumask_t crash_vmclear_enabled_bitmap = CPU_MASK_NONE;

static inline void crash_enable_local_vmclear(int cpu)
{
        cpumask_set_cpu(cpu, &crash_vmclear_enabled_bitmap);
}

static inline void crash_disable_local_vmclear(int cpu)
{
        cpumask_clear_cpu(cpu, &crash_vmclear_enabled_bitmap);
}

static inline int crash_local_vmclear_enabled(int cpu)
{
        return cpumask_test_cpu(cpu, &crash_vmclear_enabled_bitmap);
}

static void crash_vmclear_local_loaded_vmcss(void)
{
        int cpu = raw_smp_processor_id();
        struct loaded_vmcs *v;

        if (!crash_local_vmclear_enabled(cpu))
                return;

        list_for_each_entry(v, &per_cpu(loaded_vmcss_on_cpu, cpu),
                            loaded_vmcss_on_cpu_link)
                vmcs_clear(v->vmcs);
}
#else
static inline void crash_enable_local_vmclear(int cpu) { }
static inline void crash_disable_local_vmclear(int cpu) { }
#endif /* CONFIG_KEXEC */

static void __loaded_vmcs_clear(void *arg)
{
        struct loaded_vmcs *loaded_vmcs = arg;
        int cpu = raw_smp_processor_id();

        if (loaded_vmcs->cpu != cpu)
                return; /* vcpu migration can race with cpu offline */
        if (per_cpu(current_vmcs, cpu) == loaded_vmcs->vmcs)
                per_cpu(current_vmcs, cpu) = NULL;
        crash_disable_local_vmclear(cpu);
        list_del(&loaded_vmcs->loaded_vmcss_on_cpu_link);

        /*
         * we should ensure updating loaded_vmcs->loaded_vmcss_on_cpu_link
         * is before setting loaded_vmcs->vcpu to -1 which is done in
         * loaded_vmcs_init. Otherwise, other cpu can see vcpu = -1 fist
         * then adds the vmcs into percpu list before it is deleted.
         */
        smp_wmb();

        loaded_vmcs_init(loaded_vmcs);
        crash_enable_local_vmclear(cpu);
}

static void loaded_vmcs_clear(struct loaded_vmcs *loaded_vmcs)
{
        int cpu = loaded_vmcs->cpu;

        if (cpu != -1)
                smp_call_function_single(cpu,
                         __loaded_vmcs_clear, loaded_vmcs, 1);
}

static inline void vpid_sync_vcpu_single(struct vcpu_vmx *vmx)
{
        if (vmx->vpid == 0)
                return;

        if (cpu_has_vmx_invvpid_single())
                __invvpid(VMX_VPID_EXTENT_SINGLE_CONTEXT, vmx->vpid, 0);
}

static inline void vpid_sync_vcpu_global(void)
{
        if (cpu_has_vmx_invvpid_global())
                __invvpid(VMX_VPID_EXTENT_ALL_CONTEXT, 0, 0);
}

static inline void vpid_sync_context(struct vcpu_vmx *vmx)
{
        if (cpu_has_vmx_invvpid_single())
                vpid_sync_vcpu_single(vmx);
        else
                vpid_sync_vcpu_global();
}

static inline void ept_sync_global(void)
{
        if (cpu_has_vmx_invept_global())
                __invept(VMX_EPT_EXTENT_GLOBAL, 0, 0);
}

static inline void ept_sync_context(u64 eptp)
{
        if (enable_ept) {
                if (cpu_has_vmx_invept_context())
                        __invept(VMX_EPT_EXTENT_CONTEXT, eptp, 0);
                else
                        ept_sync_global();
        }
}

static __always_inline unsigned long vmcs_readl(unsigned long field)
{
        unsigned long value;

        asm volatile (__ex_clear(ASM_VMX_VMREAD_RDX_RAX, "%0")
                      : "=a"(value) : "d"(field) : "cc");
        return value;
}

static __always_inline u16 vmcs_read16(unsigned long field)
{
        return vmcs_readl(field);
}

static __always_inline u32 vmcs_read32(unsigned long field)
{
        return vmcs_readl(field);
}

static __always_inline u64 vmcs_read64(unsigned long field)
{
#ifdef CONFIG_X86_64
        return vmcs_readl(field);
#else
        return vmcs_readl(field) | ((u64)vmcs_readl(field+1) << 32);
#endif
}

static noinline void vmwrite_error(unsigned long field, unsigned long value)
{
        printk(KERN_ERR "vmwrite error: reg %lx value %lx (err %d)\n",
               field, value, vmcs_read32(VM_INSTRUCTION_ERROR));
        dump_stack();
}

static void vmcs_writel(unsigned long field, unsigned long value)
{
        u8 error;

        asm volatile (__ex(ASM_VMX_VMWRITE_RAX_RDX) "; setna %0"
                       : "=q"(error) : "a"(value), "d"(field) : "cc");
        if (unlikely(error))
                vmwrite_error(field, value);
}

static void vmcs_write16(unsigned long field, u16 value)
{
        vmcs_writel(field, value);
}

static void vmcs_write32(unsigned long field, u32 value)
{
        vmcs_writel(field, value);
}

static void vmcs_write64(unsigned long field, u64 value)
{
        vmcs_writel(field, value);
#ifndef CONFIG_X86_64
        asm volatile ("");
        vmcs_writel(field+1, value >> 32);
#endif
}

static void vmcs_clear_bits(unsigned long field, u32 mask)
{
        vmcs_writel(field, vmcs_readl(field) & ~mask);
}

static void vmcs_set_bits(unsigned long field, u32 mask)
{
        vmcs_writel(field, vmcs_readl(field) | mask);
}

static inline void vm_entry_controls_init(struct vcpu_vmx *vmx, u32 val)
{
        vmcs_write32(VM_ENTRY_CONTROLS, val);
        vmx->vm_entry_controls_shadow = val;
}

static inline void vm_entry_controls_set(struct vcpu_vmx *vmx, u32 val)
{
        if (vmx->vm_entry_controls_shadow != val)
                vm_entry_controls_init(vmx, val);
}

static inline u32 vm_entry_controls_get(struct vcpu_vmx *vmx)
{
        return vmx->vm_entry_controls_shadow;
}


static inline void vm_entry_controls_setbit(struct vcpu_vmx *vmx, u32 val)
{
        vm_entry_controls_set(vmx, vm_entry_controls_get(vmx) | val);
}

static inline void vm_entry_controls_clearbit(struct vcpu_vmx *vmx, u32 val)
{
        vm_entry_controls_set(vmx, vm_entry_controls_get(vmx) & ~val);
}

static inline void vm_exit_controls_init(struct vcpu_vmx *vmx, u32 val)
{
        vmcs_write32(VM_EXIT_CONTROLS, val);
        vmx->vm_exit_controls_shadow = val;
}

static inline void vm_exit_controls_set(struct vcpu_vmx *vmx, u32 val)
{
        if (vmx->vm_exit_controls_shadow != val)
                vm_exit_controls_init(vmx, val);
}

static inline u32 vm_exit_controls_get(struct vcpu_vmx *vmx)
{
        return vmx->vm_exit_controls_shadow;
}


static inline void vm_exit_controls_setbit(struct vcpu_vmx *vmx, u32 val)
{
        vm_exit_controls_set(vmx, vm_exit_controls_get(vmx) | val);
}

static inline void vm_exit_controls_clearbit(struct vcpu_vmx *vmx, u32 val)
{
        vm_exit_controls_set(vmx, vm_exit_controls_get(vmx) & ~val);
}

static void vmx_segment_cache_clear(struct vcpu_vmx *vmx)
{
        vmx->segment_cache.bitmask = 0;
}

static bool vmx_segment_cache_test_set(struct vcpu_vmx *vmx, unsigned seg,
                                       unsigned field)
{
        bool ret;
        u32 mask = 1 << (seg * SEG_FIELD_NR + field);

        if (!(vmx->vcpu.arch.regs_avail & (1 << VCPU_EXREG_SEGMENTS))) {
                vmx->vcpu.arch.regs_avail |= (1 << VCPU_EXREG_SEGMENTS);
                vmx->segment_cache.bitmask = 0;
        }
        ret = vmx->segment_cache.bitmask & mask;
        vmx->segment_cache.bitmask |= mask;
        return ret;
}

static u16 vmx_read_guest_seg_selector(struct vcpu_vmx *vmx, unsigned seg)
{
        u16 *p = &vmx->segment_cache.seg[seg].selector;

        if (!vmx_segment_cache_test_set(vmx, seg, SEG_FIELD_SEL))
                *p = vmcs_read16(kvm_vmx_segment_fields[seg].selector);
        return *p;
}

static ulong vmx_read_guest_seg_base(struct vcpu_vmx *vmx, unsigned seg)
{
        ulong *p = &vmx->segment_cache.seg[seg].base;

        if (!vmx_segment_cache_test_set(vmx, seg, SEG_FIELD_BASE))
                *p = vmcs_readl(kvm_vmx_segment_fields[seg].base);
        return *p;
}

static u32 vmx_read_guest_seg_limit(struct vcpu_vmx *vmx, unsigned seg)
{
        u32 *p = &vmx->segment_cache.seg[seg].limit;

        if (!vmx_segment_cache_test_set(vmx, seg, SEG_FIELD_LIMIT))
                *p = vmcs_read32(kvm_vmx_segment_fields[seg].limit);
        return *p;
}

static u32 vmx_read_guest_seg_ar(struct vcpu_vmx *vmx, unsigned seg)
{
        u32 *p = &vmx->segment_cache.seg[seg].ar;

        if (!vmx_segment_cache_test_set(vmx, seg, SEG_FIELD_AR))
                *p = vmcs_read32(kvm_vmx_segment_fields[seg].ar_bytes);
        return *p;
}

static void update_exception_bitmap(struct kvm_vcpu *vcpu)
{
        u32 eb;

        eb = (1u << PF_VECTOR) | (1u << UD_VECTOR) | (1u << MC_VECTOR) |
             (1u << NM_VECTOR) | (1u << DB_VECTOR);
        if ((vcpu->guest_debug &
             (KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_USE_SW_BP)) ==
            (KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_USE_SW_BP))
                eb |= 1u << BP_VECTOR;
        if (to_vmx(vcpu)->rmode.vm86_active)
                eb = ~0;
        if (enable_ept)
                eb &= ~(1u << PF_VECTOR); /* bypass_guest_pf = 0 */
        if (vcpu->fpu_active)
                eb &= ~(1u << NM_VECTOR);

        /* When we are running a nested L2 guest and L1 specified for it a
         * certain exception bitmap, we must trap the same exceptions and pass
         * them to L1. When running L2, we will only handle the exceptions
         * specified above if L1 did not want them.
         */
        if (is_guest_mode(vcpu))
                eb |= get_vmcs12(vcpu)->exception_bitmap;

        vmcs_write32(EXCEPTION_BITMAP, eb);
}

static void clear_atomic_switch_msr_special(struct vcpu_vmx *vmx,
                unsigned long entry, unsigned long exit)
{
        vm_entry_controls_clearbit(vmx, entry);
        vm_exit_controls_clearbit(vmx, exit);
}

static void clear_atomic_switch_msr(struct vcpu_vmx *vmx, unsigned msr)
{
        unsigned i;
        struct msr_autoload *m = &vmx->msr_autoload;

        switch (msr) {
        case MSR_EFER:
                if (cpu_has_load_ia32_efer) {
                        clear_atomic_switch_msr_special(vmx,
                                        VM_ENTRY_LOAD_IA32_EFER,
                                        VM_EXIT_LOAD_IA32_EFER);
                        return;
                }
                break;
        case MSR_CORE_PERF_GLOBAL_CTRL:
                if (cpu_has_load_perf_global_ctrl) {
                        clear_atomic_switch_msr_special(vmx,
                                        VM_ENTRY_LOAD_IA32_PERF_GLOBAL_CTRL,
                                        VM_EXIT_LOAD_IA32_PERF_GLOBAL_CTRL);
                        return;
                }
                break;
        }

        for (i = 0; i < m->nr; ++i)
                if (m->guest[i].index == msr)
                        break;

        if (i == m->nr)
                return;
        --m->nr;
        m->guest[i] = m->guest[m->nr];
        m->host[i] = m->host[m->nr];
        vmcs_write32(VM_ENTRY_MSR_LOAD_COUNT, m->nr);
        vmcs_write32(VM_EXIT_MSR_LOAD_COUNT, m->nr);
}

static void add_atomic_switch_msr_special(struct vcpu_vmx *vmx,
                unsigned long entry, unsigned long exit,
                unsigned long guest_val_vmcs, unsigned long host_val_vmcs,
                u64 guest_val, u64 host_val)
{
        vmcs_write64(guest_val_vmcs, guest_val);
        vmcs_write64(host_val_vmcs, host_val);
        vm_entry_controls_setbit(vmx, entry);
        vm_exit_controls_setbit(vmx, exit);
}

static void add_atomic_switch_msr(struct vcpu_vmx *vmx, unsigned msr,
                                  u64 guest_val, u64 host_val)
{
        unsigned i;
        struct msr_autoload *m = &vmx->msr_autoload;

        switch (msr) {
        case MSR_EFER:
                if (cpu_has_load_ia32_efer) {
                        add_atomic_switch_msr_special(vmx,
                                        VM_ENTRY_LOAD_IA32_EFER,
                                        VM_EXIT_LOAD_IA32_EFER,
                                        GUEST_IA32_EFER,
                                        HOST_IA32_EFER,
                                        guest_val, host_val);
                        return;
                }
                break;
        case MSR_CORE_PERF_GLOBAL_CTRL:
                if (cpu_has_load_perf_global_ctrl) {
                        add_atomic_switch_msr_special(vmx,
                                        VM_ENTRY_LOAD_IA32_PERF_GLOBAL_CTRL,
                                        VM_EXIT_LOAD_IA32_PERF_GLOBAL_CTRL,
                                        GUEST_IA32_PERF_GLOBAL_CTRL,
                                        HOST_IA32_PERF_GLOBAL_CTRL,
                                        guest_val, host_val);
                        return;
                }
                break;
        }

        for (i = 0; i < m->nr; ++i)
                if (m->guest[i].index == msr)
                        break;

        if (i == NR_AUTOLOAD_MSRS) {
                printk_once(KERN_WARNING "Not enough msr switch entries. "
                                "Can't add msr %x\n", msr);
                return;
        } else if (i == m->nr) {
                ++m->nr;
                vmcs_write32(VM_ENTRY_MSR_LOAD_COUNT, m->nr);
                vmcs_write32(VM_EXIT_MSR_LOAD_COUNT, m->nr);
        }

        m->guest[i].index = msr;
        m->guest[i].value = guest_val;
        m->host[i].index = msr;
        m->host[i].value = host_val;
}

static void reload_tss(void)
{
        /*
         * VT restores TR but not its size.  Useless.
         */
        struct desc_ptr *gdt = this_cpu_ptr(&host_gdt);
        struct desc_struct *descs;

        descs = (void *)gdt->address;
        descs[GDT_ENTRY_TSS].type = 9; /* available TSS */
        load_TR_desc();
}

static bool update_transition_efer(struct vcpu_vmx *vmx, int efer_offset)
{
        u64 guest_efer;
        u64 ignore_bits;

        guest_efer = vmx->vcpu.arch.efer;

        /*
         * NX is emulated; LMA and LME handled by hardware; SCE meaningless
         * outside long mode
         */
        ignore_bits = EFER_NX | EFER_SCE;
#ifdef CONFIG_X86_64
        ignore_bits |= EFER_LMA | EFER_LME;
        /* SCE is meaningful only in long mode on Intel */
        if (guest_efer & EFER_LMA)
                ignore_bits &= ~(u64)EFER_SCE;
#endif
        guest_efer &= ~ignore_bits;
        guest_efer |= host_efer & ignore_bits;
        vmx->guest_msrs[efer_offset].data = guest_efer;
        vmx->guest_msrs[efer_offset].mask = ~ignore_bits;

        clear_atomic_switch_msr(vmx, MSR_EFER);
        /* On ept, can't emulate nx, and must switch nx atomically */
        if (enable_ept && ((vmx->vcpu.arch.efer ^ host_efer) & EFER_NX)) {
                guest_efer = vmx->vcpu.arch.efer;
                if (!(guest_efer & EFER_LMA))
                        guest_efer &= ~EFER_LME;
                add_atomic_switch_msr(vmx, MSR_EFER, guest_efer, host_efer);
                return false;
        }

        return true;
}

static unsigned long segment_base(u16 selector)
{
        struct desc_ptr *gdt = this_cpu_ptr(&host_gdt);
        struct desc_struct *d;
        unsigned long table_base;
        unsigned long v;

        if (!(selector & ~3))
                return 0;

        table_base = gdt->address;

        if (selector & 4) {           /* from ldt */
                u16 ldt_selector = kvm_read_ldt();

                if (!(ldt_selector & ~3))
                        return 0;

                table_base = segment_base(ldt_selector);
        }
        d = (struct desc_struct *)(table_base + (selector & ~7));
        v = get_desc_base(d);
#ifdef CONFIG_X86_64
       if (d->s == 0 && (d->type == 2 || d->type == 9 || d->type == 11))
               v |= ((unsigned long)((struct ldttss_desc64 *)d)->base3) << 32;
#endif
        return v;
}

static inline unsigned long kvm_read_tr_base(void)
{
        u16 tr;
        asm("str %0" : "=g"(tr));
        return segment_base(tr);
}

static void vmx_save_host_state(struct kvm_vcpu *vcpu)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);
        int i;

        if (vmx->host_state.loaded)
                return;

        vmx->host_state.loaded = 1;
        /*
         * Set host fs and gs selectors.  Unfortunately, 22.2.3 does not
         * allow segment selectors with cpl > 0 or ti == 1.
         */
        vmx->host_state.ldt_sel = kvm_read_ldt();
        vmx->host_state.gs_ldt_reload_needed = vmx->host_state.ldt_sel;
        savesegment(fs, vmx->host_state.fs_sel);
        if (!(vmx->host_state.fs_sel & 7)) {
                vmcs_write16(HOST_FS_SELECTOR, vmx->host_state.fs_sel);
                vmx->host_state.fs_reload_needed = 0;
        } else {
                vmcs_write16(HOST_FS_SELECTOR, 0);
                vmx->host_state.fs_reload_needed = 1;
        }
        savesegment(gs, vmx->host_state.gs_sel);
        if (!(vmx->host_state.gs_sel & 7))
                vmcs_write16(HOST_GS_SELECTOR, vmx->host_state.gs_sel);
        else {
                vmcs_write16(HOST_GS_SELECTOR, 0);
                vmx->host_state.gs_ldt_reload_needed = 1;
        }

#ifdef CONFIG_X86_64
        savesegment(ds, vmx->host_state.ds_sel);
        savesegment(es, vmx->host_state.es_sel);
#endif

#ifdef CONFIG_X86_64
        vmcs_writel(HOST_FS_BASE, read_msr(MSR_FS_BASE));
        vmcs_writel(HOST_GS_BASE, read_msr(MSR_GS_BASE));
#else
        vmcs_writel(HOST_FS_BASE, segment_base(vmx->host_state.fs_sel));
        vmcs_writel(HOST_GS_BASE, segment_base(vmx->host_state.gs_sel));
#endif

#ifdef CONFIG_X86_64
        rdmsrl(MSR_KERNEL_GS_BASE, vmx->msr_host_kernel_gs_base);
        if (is_long_mode(&vmx->vcpu))
                wrmsrl(MSR_KERNEL_GS_BASE, vmx->msr_guest_kernel_gs_base);
#endif
        if (boot_cpu_has(X86_FEATURE_MPX))
                rdmsrl(MSR_IA32_BNDCFGS, vmx->host_state.msr_host_bndcfgs);
        for (i = 0; i < vmx->save_nmsrs; ++i)
                kvm_set_shared_msr(vmx->guest_msrs[i].index,
                                   vmx->guest_msrs[i].data,
                                   vmx->guest_msrs[i].mask);
}

static void __vmx_load_host_state(struct vcpu_vmx *vmx)
{
        if (!vmx->host_state.loaded)
                return;

        ++vmx->vcpu.stat.host_state_reload;
        vmx->host_state.loaded = 0;
#ifdef CONFIG_X86_64
        if (is_long_mode(&vmx->vcpu))
                rdmsrl(MSR_KERNEL_GS_BASE, vmx->msr_guest_kernel_gs_base);
#endif
        if (vmx->host_state.gs_ldt_reload_needed) {
                kvm_load_ldt(vmx->host_state.ldt_sel);
#ifdef CONFIG_X86_64
                load_gs_index(vmx->host_state.gs_sel);
#else
                loadsegment(gs, vmx->host_state.gs_sel);
#endif
        }
        if (vmx->host_state.fs_reload_needed)
                loadsegment(fs, vmx->host_state.fs_sel);
#ifdef CONFIG_X86_64
        if (unlikely(vmx->host_state.ds_sel | vmx->host_state.es_sel)) {
                loadsegment(ds, vmx->host_state.ds_sel);
                loadsegment(es, vmx->host_state.es_sel);
        }
#endif
        reload_tss();
#ifdef CONFIG_X86_64
        wrmsrl(MSR_KERNEL_GS_BASE, vmx->msr_host_kernel_gs_base);
#endif
        if (vmx->host_state.msr_host_bndcfgs)
                wrmsrl(MSR_IA32_BNDCFGS, vmx->host_state.msr_host_bndcfgs);
        /*
         * If the FPU is not active (through the host task or
         * the guest vcpu), then restore the cr0.TS bit.
         */
        if (!user_has_fpu() && !vmx->vcpu.guest_fpu_loaded)
                stts();
        load_gdt(this_cpu_ptr(&host_gdt));
}

static void vmx_load_host_state(struct vcpu_vmx *vmx)
{
        preempt_disable();
        __vmx_load_host_state(vmx);
        preempt_enable();
}

/*
 * Switches to specified vcpu, until a matching vcpu_put(), but assumes
 * vcpu mutex is already taken.
 */
static void vmx_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);
        u64 phys_addr = __pa(per_cpu(vmxarea, cpu));

        if (!vmm_exclusive)
                kvm_cpu_vmxon(phys_addr);
        else if (vmx->loaded_vmcs->cpu != cpu)
                loaded_vmcs_clear(vmx->loaded_vmcs);

        if (per_cpu(current_vmcs, cpu) != vmx->loaded_vmcs->vmcs) {
                per_cpu(current_vmcs, cpu) = vmx->loaded_vmcs->vmcs;
                vmcs_load(vmx->loaded_vmcs->vmcs);
        }

        if (vmx->loaded_vmcs->cpu != cpu) {
                struct desc_ptr *gdt = this_cpu_ptr(&host_gdt);
                unsigned long sysenter_esp;

                kvm_make_request(KVM_REQ_TLB_FLUSH, vcpu);
                local_irq_disable();
                crash_disable_local_vmclear(cpu);

                /*
                 * Read loaded_vmcs->cpu should be before fetching
                 * loaded_vmcs->loaded_vmcss_on_cpu_link.
                 * See the comments in __loaded_vmcs_clear().
                 */
                smp_rmb();

                list_add(&vmx->loaded_vmcs->loaded_vmcss_on_cpu_link,
                         &per_cpu(loaded_vmcss_on_cpu, cpu));
                crash_enable_local_vmclear(cpu);
                local_irq_enable();

                /*
                 * Linux uses per-cpu TSS and GDT, so set these when switching
                 * processors.
                 */
                vmcs_writel(HOST_TR_BASE, kvm_read_tr_base()); /* 22.2.4 */
                vmcs_writel(HOST_GDTR_BASE, gdt->address);   /* 22.2.4 */

                rdmsrl(MSR_IA32_SYSENTER_ESP, sysenter_esp);
                vmcs_writel(HOST_IA32_SYSENTER_ESP, sysenter_esp); /* 22.2.3 */
                vmx->loaded_vmcs->cpu = cpu;
        }
}

static void vmx_vcpu_put(struct kvm_vcpu *vcpu)
{
        __vmx_load_host_state(to_vmx(vcpu));
        if (!vmm_exclusive) {
                __loaded_vmcs_clear(to_vmx(vcpu)->loaded_vmcs);
                vcpu->cpu = -1;
                kvm_cpu_vmxoff();
        }
}

static void vmx_fpu_activate(struct kvm_vcpu *vcpu)
{
        ulong cr0;

        if (vcpu->fpu_active)
                return;
        vcpu->fpu_active = 1;
        cr0 = vmcs_readl(GUEST_CR0);
        cr0 &= ~(X86_CR0_TS | X86_CR0_MP);
        cr0 |= kvm_read_cr0_bits(vcpu, X86_CR0_TS | X86_CR0_MP);
        vmcs_writel(GUEST_CR0, cr0);
        update_exception_bitmap(vcpu);
        vcpu->arch.cr0_guest_owned_bits = X86_CR0_TS;
        if (is_guest_mode(vcpu))
                vcpu->arch.cr0_guest_owned_bits &=
                        ~get_vmcs12(vcpu)->cr0_guest_host_mask;
        vmcs_writel(CR0_GUEST_HOST_MASK, ~vcpu->arch.cr0_guest_owned_bits);
}

static void vmx_decache_cr0_guest_bits(struct kvm_vcpu *vcpu);

/*
 * Return the cr0 value that a nested guest would read. This is a combination
 * of the real cr0 used to run the guest (guest_cr0), and the bits shadowed by
 * its hypervisor (cr0_read_shadow).
 */
static inline unsigned long nested_read_cr0(struct vmcs12 *fields)
{
        return (fields->guest_cr0 & ~fields->cr0_guest_host_mask) |
                (fields->cr0_read_shadow & fields->cr0_guest_host_mask);
}
static inline unsigned long nested_read_cr4(struct vmcs12 *fields)
{
        return (fields->guest_cr4 & ~fields->cr4_guest_host_mask) |
                (fields->cr4_read_shadow & fields->cr4_guest_host_mask);
}

static void vmx_fpu_deactivate(struct kvm_vcpu *vcpu)
{
        /* Note that there is no vcpu->fpu_active = 0 here. The caller must
         * set this *before* calling this function.
         */
        vmx_decache_cr0_guest_bits(vcpu);
        vmcs_set_bits(GUEST_CR0, X86_CR0_TS | X86_CR0_MP);
        update_exception_bitmap(vcpu);
        vcpu->arch.cr0_guest_owned_bits = 0;
        vmcs_writel(CR0_GUEST_HOST_MASK, ~vcpu->arch.cr0_guest_owned_bits);
        if (is_guest_mode(vcpu)) {
                /*
                 * L1's specified read shadow might not contain the TS bit,
                 * so now that we turned on shadowing of this bit, we need to
                 * set this bit of the shadow. Like in nested_vmx_run we need
                 * nested_read_cr0(vmcs12), but vmcs12->guest_cr0 is not yet
                 * up-to-date here because we just decached cr0.TS (and we'll
                 * only update vmcs12->guest_cr0 on nested exit).
                 */
                struct vmcs12 *vmcs12 = get_vmcs12(vcpu);
                vmcs12->guest_cr0 = (vmcs12->guest_cr0 & ~X86_CR0_TS) |
                        (vcpu->arch.cr0 & X86_CR0_TS);
                vmcs_writel(CR0_READ_SHADOW, nested_read_cr0(vmcs12));
        } else
                vmcs_writel(CR0_READ_SHADOW, vcpu->arch.cr0);
}

static unsigned long vmx_get_rflags(struct kvm_vcpu *vcpu)
{
        unsigned long rflags, save_rflags;

        if (!test_bit(VCPU_EXREG_RFLAGS, (ulong *)&vcpu->arch.regs_avail)) {
                __set_bit(VCPU_EXREG_RFLAGS, (ulong *)&vcpu->arch.regs_avail);
                rflags = vmcs_readl(GUEST_RFLAGS);
                if (to_vmx(vcpu)->rmode.vm86_active) {
                        rflags &= RMODE_GUEST_OWNED_EFLAGS_BITS;
                        save_rflags = to_vmx(vcpu)->rmode.save_rflags;
                        rflags |= save_rflags & ~RMODE_GUEST_OWNED_EFLAGS_BITS;
                }
                to_vmx(vcpu)->rflags = rflags;
        }
        return to_vmx(vcpu)->rflags;
}

static void vmx_set_rflags(struct kvm_vcpu *vcpu, unsigned long rflags)
{
        __set_bit(VCPU_EXREG_RFLAGS, (ulong *)&vcpu->arch.regs_avail);
        to_vmx(vcpu)->rflags = rflags;
        if (to_vmx(vcpu)->rmode.vm86_active) {
                to_vmx(vcpu)->rmode.save_rflags = rflags;
                rflags |= X86_EFLAGS_IOPL | X86_EFLAGS_VM;
        }
        vmcs_writel(GUEST_RFLAGS, rflags);
}

static u32 vmx_get_interrupt_shadow(struct kvm_vcpu *vcpu)
{
        u32 interruptibility = vmcs_read32(GUEST_INTERRUPTIBILITY_INFO);
        int ret = 0;

        if (interruptibility & GUEST_INTR_STATE_STI)
                ret |= KVM_X86_SHADOW_INT_STI;
        if (interruptibility & GUEST_INTR_STATE_MOV_SS)
                ret |= KVM_X86_SHADOW_INT_MOV_SS;

        return ret;
}

static void vmx_set_interrupt_shadow(struct kvm_vcpu *vcpu, int mask)
{
        u32 interruptibility_old = vmcs_read32(GUEST_INTERRUPTIBILITY_INFO);
        u32 interruptibility = interruptibility_old;

        interruptibility &= ~(GUEST_INTR_STATE_STI | GUEST_INTR_STATE_MOV_SS);

        if (mask & KVM_X86_SHADOW_INT_MOV_SS)
                interruptibility |= GUEST_INTR_STATE_MOV_SS;
        else if (mask & KVM_X86_SHADOW_INT_STI)
                interruptibility |= GUEST_INTR_STATE_STI;

        if ((interruptibility != interruptibility_old))
                vmcs_write32(GUEST_INTERRUPTIBILITY_INFO, interruptibility);
}

static void skip_emulated_instruction(struct kvm_vcpu *vcpu)
{
        unsigned long rip;

        rip = kvm_rip_read(vcpu);
        rip += vmcs_read32(VM_EXIT_INSTRUCTION_LEN);
        kvm_rip_write(vcpu, rip);

        /* skipping an emulated instruction also counts */
        vmx_set_interrupt_shadow(vcpu, 0);
}

/*
 * KVM wants to inject page-faults which it got to the guest. This function
 * checks whether in a nested guest, we need to inject them to L1 or L2.
 */
static int nested_vmx_check_exception(struct kvm_vcpu *vcpu, unsigned nr)
{
        struct vmcs12 *vmcs12 = get_vmcs12(vcpu);

        if (!(vmcs12->exception_bitmap & (1u << nr)))
                return 0;

        nested_vmx_vmexit(vcpu, to_vmx(vcpu)->exit_reason,
                          vmcs_read32(VM_EXIT_INTR_INFO),
                          vmcs_readl(EXIT_QUALIFICATION));
        return 1;
}

static void vmx_queue_exception(struct kvm_vcpu *vcpu, unsigned nr,
                                bool has_error_code, u32 error_code,
                                bool reinject)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);
        u32 intr_info = nr | INTR_INFO_VALID_MASK;

        if (!reinject && is_guest_mode(vcpu) &&
            nested_vmx_check_exception(vcpu, nr))
                return;

        if (has_error_code) {
                vmcs_write32(VM_ENTRY_EXCEPTION_ERROR_CODE, error_code);
                intr_info |= INTR_INFO_DELIVER_CODE_MASK;
        }

        if (vmx->rmode.vm86_active) {
                int inc_eip = 0;
                if (kvm_exception_is_soft(nr))
                        inc_eip = vcpu->arch.event_exit_inst_len;
                if (kvm_inject_realmode_interrupt(vcpu, nr, inc_eip) != EMULATE_DONE)
                        kvm_make_request(KVM_REQ_TRIPLE_FAULT, vcpu);
                return;
        }

        if (kvm_exception_is_soft(nr)) {
                vmcs_write32(VM_ENTRY_INSTRUCTION_LEN,
                             vmx->vcpu.arch.event_exit_inst_len);
                intr_info |= INTR_TYPE_SOFT_EXCEPTION;
        } else
                intr_info |= INTR_TYPE_HARD_EXCEPTION;

        vmcs_write32(VM_ENTRY_INTR_INFO_FIELD, intr_info);
}

static bool vmx_rdtscp_supported(void)
{
        return cpu_has_vmx_rdtscp();
}

static bool vmx_invpcid_supported(void)
{
        return cpu_has_vmx_invpcid() && enable_ept;
}

/*
 * Swap MSR entry in host/guest MSR entry array.
 */
static void move_msr_up(struct vcpu_vmx *vmx, int from, int to)
{
        struct shared_msr_entry tmp;

        tmp = vmx->guest_msrs[to];
        vmx->guest_msrs[to] = vmx->guest_msrs[from];
        vmx->guest_msrs[from] = tmp;
}

static void vmx_set_msr_bitmap(struct kvm_vcpu *vcpu)
{
        unsigned long *msr_bitmap;

        if (irqchip_in_kernel(vcpu->kvm) && apic_x2apic_mode(vcpu->arch.apic)) {
                if (is_long_mode(vcpu))
                        msr_bitmap = vmx_msr_bitmap_longmode_x2apic;
                else
                        msr_bitmap = vmx_msr_bitmap_legacy_x2apic;
        } else {
                if (is_long_mode(vcpu))
                        msr_bitmap = vmx_msr_bitmap_longmode;
                else
                        msr_bitmap = vmx_msr_bitmap_legacy;
        }

        vmcs_write64(MSR_BITMAP, __pa(msr_bitmap));
}

/*
 * Set up the vmcs to automatically save and restore system
 * msrs.  Don't touch the 64-bit msrs if the guest is in legacy
 * mode, as fiddling with msrs is very expensive.
 */
static void setup_msrs(struct vcpu_vmx *vmx)
{
        int save_nmsrs, index;

        save_nmsrs = 0;
#ifdef CONFIG_X86_64
        if (is_long_mode(&vmx->vcpu)) {
                index = __find_msr_index(vmx, MSR_SYSCALL_MASK);
                if (index >= 0)
                        move_msr_up(vmx, index, save_nmsrs++);
                index = __find_msr_index(vmx, MSR_LSTAR);
                if (index >= 0)
                        move_msr_up(vmx, index, save_nmsrs++);
                index = __find_msr_index(vmx, MSR_CSTAR);
                if (index >= 0)
                        move_msr_up(vmx, index, save_nmsrs++);
                index = __find_msr_index(vmx, MSR_TSC_AUX);
                if (index >= 0 && vmx->rdtscp_enabled)
                        move_msr_up(vmx, index, save_nmsrs++);
                /*
                 * MSR_STAR is only needed on long mode guests, and only
                 * if efer.sce is enabled.
                 */
                index = __find_msr_index(vmx, MSR_STAR);
                if ((index >= 0) && (vmx->vcpu.arch.efer & EFER_SCE))
                        move_msr_up(vmx, index, save_nmsrs++);
        }
#endif
        index = __find_msr_index(vmx, MSR_EFER);
        if (index >= 0 && update_transition_efer(vmx, index))
                move_msr_up(vmx, index, save_nmsrs++);

        vmx->save_nmsrs = save_nmsrs;

        if (cpu_has_vmx_msr_bitmap())
                vmx_set_msr_bitmap(&vmx->vcpu);
}

/*
 * reads and returns guest's timestamp counter "register"
 * guest_tsc = host_tsc + tsc_offset    -- 21.3
 */
static u64 guest_read_tsc(void)
{
        u64 host_tsc, tsc_offset;

        rdtscll(host_tsc);
        tsc_offset = vmcs_read64(TSC_OFFSET);
        return host_tsc + tsc_offset;
}

/*
 * Like guest_read_tsc, but always returns L1's notion of the timestamp
 * counter, even if a nested guest (L2) is currently running.
 */
static u64 vmx_read_l1_tsc(struct kvm_vcpu *vcpu, u64 host_tsc)
{
        u64 tsc_offset;

        tsc_offset = is_guest_mode(vcpu) ?
                to_vmx(vcpu)->nested.vmcs01_tsc_offset :
                vmcs_read64(TSC_OFFSET);
        return host_tsc + tsc_offset;
}

/*
 * Engage any workarounds for mis-matched TSC rates.  Currently limited to
 * software catchup for faster rates on slower CPUs.
 */
static void vmx_set_tsc_khz(struct kvm_vcpu *vcpu, u32 user_tsc_khz, bool scale)
{
        if (!scale)
                return;

        if (user_tsc_khz > tsc_khz) {
                vcpu->arch.tsc_catchup = 1;
                vcpu->arch.tsc_always_catchup = 1;
        } else
                WARN(1, "user requested TSC rate below hardware speed\n");
}

static u64 vmx_read_tsc_offset(struct kvm_vcpu *vcpu)
{
        return vmcs_read64(TSC_OFFSET);
}

/*
 * writes 'offset' into guest's timestamp counter offset register
 */
static void vmx_write_tsc_offset(struct kvm_vcpu *vcpu, u64 offset)
{
        if (is_guest_mode(vcpu)) {
                /*
                 * We're here if L1 chose not to trap WRMSR to TSC. According
                 * to the spec, this should set L1's TSC; The offset that L1
                 * set for L2 remains unchanged, and still needs to be added
                 * to the newly set TSC to get L2's TSC.
                 */
                struct vmcs12 *vmcs12;
                to_vmx(vcpu)->nested.vmcs01_tsc_offset = offset;
                /* recalculate vmcs02.TSC_OFFSET: */
                vmcs12 = get_vmcs12(vcpu);
                vmcs_write64(TSC_OFFSET, offset +
                        (nested_cpu_has(vmcs12, CPU_BASED_USE_TSC_OFFSETING) ?
                         vmcs12->tsc_offset : 0));
        } else {
                trace_kvm_write_tsc_offset(vcpu->vcpu_id,
                                           vmcs_read64(TSC_OFFSET), offset);
                vmcs_write64(TSC_OFFSET, offset);
        }
}

static void vmx_adjust_tsc_offset(struct kvm_vcpu *vcpu, s64 adjustment, bool host)
{
        u64 offset = vmcs_read64(TSC_OFFSET);

        vmcs_write64(TSC_OFFSET, offset + adjustment);
        if (is_guest_mode(vcpu)) {
                /* Even when running L2, the adjustment needs to apply to L1 */
                to_vmx(vcpu)->nested.vmcs01_tsc_offset += adjustment;
        } else
                trace_kvm_write_tsc_offset(vcpu->vcpu_id, offset,
                                           offset + adjustment);
}

static u64 vmx_compute_tsc_offset(struct kvm_vcpu *vcpu, u64 target_tsc)
{
        return target_tsc - native_read_tsc();
}

static bool guest_cpuid_has_vmx(struct kvm_vcpu *vcpu)
{
        struct kvm_cpuid_entry2 *best = kvm_find_cpuid_entry(vcpu, 1, 0);
        return best && (best->ecx & (1 << (X86_FEATURE_VMX & 31)));
}

/*
 * nested_vmx_allowed() checks whether a guest should be allowed to use VMX
 * instructions and MSRs (i.e., nested VMX). Nested VMX is disabled for
 * all guests if the "nested" module option is off, and can also be disabled
 * for a single guest by disabling its VMX cpuid bit.
 */
static inline bool nested_vmx_allowed(struct kvm_vcpu *vcpu)
{
        return nested && guest_cpuid_has_vmx(vcpu);
}

/*
 * nested_vmx_setup_ctls_msrs() sets up variables containing the values to be
 * returned for the various VMX controls MSRs when nested VMX is enabled.
 * The same values should also be used to verify that vmcs12 control fields are
 * valid during nested entry from L1 to L2.
 * Each of these control msrs has a low and high 32-bit half: A low bit is on
 * if the corresponding bit in the (32-bit) control field *must* be on, and a
 * bit in the high half is on if the corresponding bit in the control field
 * may be on. See also vmx_control_verify().
 * TODO: allow these variables to be modified (downgraded) by module options
 * or other means.
 */
static u32 nested_vmx_procbased_ctls_low, nested_vmx_procbased_ctls_high;
static u32 nested_vmx_true_procbased_ctls_low;
static u32 nested_vmx_secondary_ctls_low, nested_vmx_secondary_ctls_high;
static u32 nested_vmx_pinbased_ctls_low, nested_vmx_pinbased_ctls_high;
static u32 nested_vmx_exit_ctls_low, nested_vmx_exit_ctls_high;
static u32 nested_vmx_true_exit_ctls_low;
static u32 nested_vmx_entry_ctls_low, nested_vmx_entry_ctls_high;
static u32 nested_vmx_true_entry_ctls_low;
static u32 nested_vmx_misc_low, nested_vmx_misc_high;
static u32 nested_vmx_ept_caps;
static __init void nested_vmx_setup_ctls_msrs(void)
{
        /*
         * Note that as a general rule, the high half of the MSRs (bits in
         * the control fields which may be 1) should be initialized by the
         * intersection of the underlying hardware's MSR (i.e., features which
         * can be supported) and the list of features we want to expose -
         * because they are known to be properly supported in our code.
         * Also, usually, the low half of the MSRs (bits which must be 1) can
         * be set to 0, meaning that L1 may turn off any of these bits. The
         * reason is that if one of these bits is necessary, it will appear
         * in vmcs01 and prepare_vmcs02, when it bitwise-or's the control
         * fields of vmcs01 and vmcs02, will turn these bits off - and
         * nested_vmx_exit_handled() will not pass related exits to L1.
         * These rules have exceptions below.
         */

        /* pin-based controls */
        rdmsr(MSR_IA32_VMX_PINBASED_CTLS,
              nested_vmx_pinbased_ctls_low, nested_vmx_pinbased_ctls_high);
        nested_vmx_pinbased_ctls_low |= PIN_BASED_ALWAYSON_WITHOUT_TRUE_MSR;
        nested_vmx_pinbased_ctls_high &= PIN_BASED_EXT_INTR_MASK |
                PIN_BASED_NMI_EXITING | PIN_BASED_VIRTUAL_NMIS;
        nested_vmx_pinbased_ctls_high |= PIN_BASED_ALWAYSON_WITHOUT_TRUE_MSR |
                PIN_BASED_VMX_PREEMPTION_TIMER;

        /* exit controls */
        rdmsr(MSR_IA32_VMX_EXIT_CTLS,
                nested_vmx_exit_ctls_low, nested_vmx_exit_ctls_high);
        nested_vmx_exit_ctls_low = VM_EXIT_ALWAYSON_WITHOUT_TRUE_MSR;

        nested_vmx_exit_ctls_high &=
#ifdef CONFIG_X86_64
                VM_EXIT_HOST_ADDR_SPACE_SIZE |
#endif
                VM_EXIT_LOAD_IA32_PAT | VM_EXIT_SAVE_IA32_PAT;
        nested_vmx_exit_ctls_high |= VM_EXIT_ALWAYSON_WITHOUT_TRUE_MSR |
                VM_EXIT_LOAD_IA32_EFER | VM_EXIT_SAVE_IA32_EFER |
                VM_EXIT_SAVE_VMX_PREEMPTION_TIMER | VM_EXIT_ACK_INTR_ON_EXIT;

        if (vmx_mpx_supported())
                nested_vmx_exit_ctls_high |= VM_EXIT_CLEAR_BNDCFGS;

        /* We support free control of debug control saving. */
        nested_vmx_true_exit_ctls_low = nested_vmx_exit_ctls_low &
                ~VM_EXIT_SAVE_DEBUG_CONTROLS;

        /* entry controls */
        rdmsr(MSR_IA32_VMX_ENTRY_CTLS,
                nested_vmx_entry_ctls_low, nested_vmx_entry_ctls_high);
        nested_vmx_entry_ctls_low = VM_ENTRY_ALWAYSON_WITHOUT_TRUE_MSR;
        nested_vmx_entry_ctls_high &=
#ifdef CONFIG_X86_64
                VM_ENTRY_IA32E_MODE |
#endif
                VM_ENTRY_LOAD_IA32_PAT;
        nested_vmx_entry_ctls_high |= (VM_ENTRY_ALWAYSON_WITHOUT_TRUE_MSR |
                                       VM_ENTRY_LOAD_IA32_EFER);
        if (vmx_mpx_supported())
                nested_vmx_entry_ctls_high |= VM_ENTRY_LOAD_BNDCFGS;

        /* We support free control of debug control loading. */
        nested_vmx_true_entry_ctls_low = nested_vmx_entry_ctls_low &
                ~VM_ENTRY_LOAD_DEBUG_CONTROLS;

        /* cpu-based controls */
        rdmsr(MSR_IA32_VMX_PROCBASED_CTLS,
                nested_vmx_procbased_ctls_low, nested_vmx_procbased_ctls_high);
        nested_vmx_procbased_ctls_low = CPU_BASED_ALWAYSON_WITHOUT_TRUE_MSR;
        nested_vmx_procbased_ctls_high &=
                CPU_BASED_VIRTUAL_INTR_PENDING |
                CPU_BASED_VIRTUAL_NMI_PENDING | CPU_BASED_USE_TSC_OFFSETING |
                CPU_BASED_HLT_EXITING | CPU_BASED_INVLPG_EXITING |
                CPU_BASED_MWAIT_EXITING | CPU_BASED_CR3_LOAD_EXITING |
                CPU_BASED_CR3_STORE_EXITING |
#ifdef CONFIG_X86_64
                CPU_BASED_CR8_LOAD_EXITING | CPU_BASED_CR8_STORE_EXITING |
#endif
                CPU_BASED_MOV_DR_EXITING | CPU_BASED_UNCOND_IO_EXITING |
                CPU_BASED_USE_IO_BITMAPS | CPU_BASED_MONITOR_EXITING |
                CPU_BASED_RDPMC_EXITING | CPU_BASED_RDTSC_EXITING |
                CPU_BASED_PAUSE_EXITING | CPU_BASED_TPR_SHADOW |
                CPU_BASED_ACTIVATE_SECONDARY_CONTROLS;
        /*
         * We can allow some features even when not supported by the
         * hardware. For example, L1 can specify an MSR bitmap - and we
         * can use it to avoid exits to L1 - even when L0 runs L2
         * without MSR bitmaps.
         */
        nested_vmx_procbased_ctls_high |= CPU_BASED_ALWAYSON_WITHOUT_TRUE_MSR |
                CPU_BASED_USE_MSR_BITMAPS;

        /* We support free control of CR3 access interception. */
        nested_vmx_true_procbased_ctls_low = nested_vmx_procbased_ctls_low &
                ~(CPU_BASED_CR3_LOAD_EXITING | CPU_BASED_CR3_STORE_EXITING);

        /* secondary cpu-based controls */
        rdmsr(MSR_IA32_VMX_PROCBASED_CTLS2,
                nested_vmx_secondary_ctls_low, nested_vmx_secondary_ctls_high);
        nested_vmx_secondary_ctls_low = 0;
        nested_vmx_secondary_ctls_high &=
                SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES |
                SECONDARY_EXEC_UNRESTRICTED_GUEST |
                SECONDARY_EXEC_WBINVD_EXITING;

        if (enable_ept) {
                /* nested EPT: emulate EPT also to L1 */
                nested_vmx_secondary_ctls_high |= SECONDARY_EXEC_ENABLE_EPT;
                nested_vmx_ept_caps = VMX_EPT_PAGE_WALK_4_BIT |
                         VMX_EPTP_WB_BIT | VMX_EPT_2MB_PAGE_BIT |
                         VMX_EPT_INVEPT_BIT;
                nested_vmx_ept_caps &= vmx_capability.ept;
                /*
                 * For nested guests, we don't do anything specific
                 * for single context invalidation. Hence, only advertise
                 * support for global context invalidation.
                 */
                nested_vmx_ept_caps |= VMX_EPT_EXTENT_GLOBAL_BIT;
        } else
                nested_vmx_ept_caps = 0;

        /* miscellaneous data */
        rdmsr(MSR_IA32_VMX_MISC, nested_vmx_misc_low, nested_vmx_misc_high);
        nested_vmx_misc_low &= VMX_MISC_SAVE_EFER_LMA;
        nested_vmx_misc_low |= VMX_MISC_EMULATED_PREEMPTION_TIMER_RATE |
                VMX_MISC_ACTIVITY_HLT;
        nested_vmx_misc_high = 0;
}

static inline bool vmx_control_verify(u32 control, u32 low, u32 high)
{
        /*
         * Bits 0 in high must be 0, and bits 1 in low must be 1.
         */
        return ((control & high) | low) == control;
}

static inline u64 vmx_control_msr(u32 low, u32 high)
{
        return low | ((u64)high << 32);
}

/* Returns 0 on success, non-0 otherwise. */
static int vmx_get_vmx_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 *pdata)
{
        switch (msr_index) {
        case MSR_IA32_VMX_BASIC:
                /*
                 * This MSR reports some information about VMX support. We
                 * should return information about the VMX we emulate for the
                 * guest, and the VMCS structure we give it - not about the
                 * VMX support of the underlying hardware.
                 */
                *pdata = VMCS12_REVISION | VMX_BASIC_TRUE_CTLS |
                           ((u64)VMCS12_SIZE << VMX_BASIC_VMCS_SIZE_SHIFT) |
                           (VMX_BASIC_MEM_TYPE_WB << VMX_BASIC_MEM_TYPE_SHIFT);
                break;
        case MSR_IA32_VMX_TRUE_PINBASED_CTLS:
        case MSR_IA32_VMX_PINBASED_CTLS:
                *pdata = vmx_control_msr(nested_vmx_pinbased_ctls_low,
                                        nested_vmx_pinbased_ctls_high);
                break;
        case MSR_IA32_VMX_TRUE_PROCBASED_CTLS:
                *pdata = vmx_control_msr(nested_vmx_true_procbased_ctls_low,
                                        nested_vmx_procbased_ctls_high);
                break;
        case MSR_IA32_VMX_PROCBASED_CTLS:
                *pdata = vmx_control_msr(nested_vmx_procbased_ctls_low,
                                        nested_vmx_procbased_ctls_high);
                break;
        case MSR_IA32_VMX_TRUE_EXIT_CTLS:
                *pdata = vmx_control_msr(nested_vmx_true_exit_ctls_low,
                                        nested_vmx_exit_ctls_high);
                break;
        case MSR_IA32_VMX_EXIT_CTLS:
                *pdata = vmx_control_msr(nested_vmx_exit_ctls_low,
                                        nested_vmx_exit_ctls_high);
                break;
        case MSR_IA32_VMX_TRUE_ENTRY_CTLS:
                *pdata = vmx_control_msr(nested_vmx_true_entry_ctls_low,
                                        nested_vmx_entry_ctls_high);
                break;
        case MSR_IA32_VMX_ENTRY_CTLS:
                *pdata = vmx_control_msr(nested_vmx_entry_ctls_low,
                                        nested_vmx_entry_ctls_high);
                break;
        case MSR_IA32_VMX_MISC:
                *pdata = vmx_control_msr(nested_vmx_misc_low,
                                         nested_vmx_misc_high);
                break;
        /*
         * These MSRs specify bits which the guest must keep fixed (on or off)
         * while L1 is in VMXON mode (in L1's root mode, or running an L2).
         * We picked the standard core2 setting.
         */
#define VMXON_CR0_ALWAYSON      (X86_CR0_PE | X86_CR0_PG | X86_CR0_NE)
#define VMXON_CR4_ALWAYSON      X86_CR4_VMXE
        case MSR_IA32_VMX_CR0_FIXED0:
                *pdata = VMXON_CR0_ALWAYSON;
                break;
        case MSR_IA32_VMX_CR0_FIXED1:
                *pdata = -1ULL;
                break;
        case MSR_IA32_VMX_CR4_FIXED0:
                *pdata = VMXON_CR4_ALWAYSON;
                break;
        case MSR_IA32_VMX_CR4_FIXED1:
                *pdata = -1ULL;
                break;
        case MSR_IA32_VMX_VMCS_ENUM:
                *pdata = 0x2e; /* highest index: VMX_PREEMPTION_TIMER_VALUE */
                break;
        case MSR_IA32_VMX_PROCBASED_CTLS2:
                *pdata = vmx_control_msr(nested_vmx_secondary_ctls_low,
                                        nested_vmx_secondary_ctls_high);
                break;
        case MSR_IA32_VMX_EPT_VPID_CAP:
                /* Currently, no nested vpid support */
                *pdata = nested_vmx_ept_caps;
                break;
        default:
                return 1;
        }

        return 0;
}

/*
 * Reads an msr value (of 'msr_index') into 'pdata'.
 * Returns 0 on success, non-0 otherwise.
 * Assumes vcpu_load() was already called.
 */
static int vmx_get_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 *pdata)
{
        u64 data;
        struct shared_msr_entry *msr;

        if (!pdata) {
                printk(KERN_ERR "BUG: get_msr called with NULL pdata\n");
                return -EINVAL;
        }

        switch (msr_index) {
#ifdef CONFIG_X86_64
        case MSR_FS_BASE:
                data = vmcs_readl(GUEST_FS_BASE);
                break;
        case MSR_GS_BASE:
                data = vmcs_readl(GUEST_GS_BASE);
                break;
        case MSR_KERNEL_GS_BASE:
                vmx_load_host_state(to_vmx(vcpu));
                data = to_vmx(vcpu)->msr_guest_kernel_gs_base;
                break;
#endif
        case MSR_EFER:
                return kvm_get_msr_common(vcpu, msr_index, pdata);
        case MSR_IA32_TSC:
                data = guest_read_tsc();
                break;
        case MSR_IA32_SYSENTER_CS:
                data = vmcs_read32(GUEST_SYSENTER_CS);
                break;
        case MSR_IA32_SYSENTER_EIP:
                data = vmcs_readl(GUEST_SYSENTER_EIP);
                break;
        case MSR_IA32_SYSENTER_ESP:
                data = vmcs_readl(GUEST_SYSENTER_ESP);
                break;
        case MSR_IA32_BNDCFGS:
                if (!vmx_mpx_supported())
                        return 1;
                data = vmcs_read64(GUEST_BNDCFGS);
                break;
        case MSR_IA32_FEATURE_CONTROL:
                if (!nested_vmx_allowed(vcpu))
                        return 1;
                data = to_vmx(vcpu)->nested.msr_ia32_feature_control;
                break;
        case MSR_IA32_VMX_BASIC ... MSR_IA32_VMX_VMFUNC:
                if (!nested_vmx_allowed(vcpu))
                        return 1;
                return vmx_get_vmx_msr(vcpu, msr_index, pdata);
        case MSR_TSC_AUX:
                if (!to_vmx(vcpu)->rdtscp_enabled)
                        return 1;
                /* Otherwise falls through */
        default:
                msr = find_msr_entry(to_vmx(vcpu), msr_index);
                if (msr) {
                        data = msr->data;
                        break;
                }
                return kvm_get_msr_common(vcpu, msr_index, pdata);
        }

        *pdata = data;
        return 0;
}

static void vmx_leave_nested(struct kvm_vcpu *vcpu);

/*
 * Writes msr value into into the appropriate "register".
 * Returns 0 on success, non-0 otherwise.
 * Assumes vcpu_load() was already called.
 */
static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);
        struct shared_msr_entry *msr;
        int ret = 0;
        u32 msr_index = msr_info->index;
        u64 data = msr_info->data;

        switch (msr_index) {
        case MSR_EFER:
                ret = kvm_set_msr_common(vcpu, msr_info);
                break;
#ifdef CONFIG_X86_64
        case MSR_FS_BASE:
                vmx_segment_cache_clear(vmx);
                vmcs_writel(GUEST_FS_BASE, data);
                break;
        case MSR_GS_BASE:
                vmx_segment_cache_clear(vmx);
                vmcs_writel(GUEST_GS_BASE, data);
                break;
        case MSR_KERNEL_GS_BASE:
                vmx_load_host_state(vmx);
                vmx->msr_guest_kernel_gs_base = data;
                break;
#endif
        case MSR_IA32_SYSENTER_CS:
                vmcs_write32(GUEST_SYSENTER_CS, data);
                break;
        case MSR_IA32_SYSENTER_EIP:
                vmcs_writel(GUEST_SYSENTER_EIP, data);
                break;
        case MSR_IA32_SYSENTER_ESP:
                vmcs_writel(GUEST_SYSENTER_ESP, data);
                break;
        case MSR_IA32_BNDCFGS:
                if (!vmx_mpx_supported())
                        return 1;
                vmcs_write64(GUEST_BNDCFGS, data);
                break;
        case MSR_IA32_TSC:
                kvm_write_tsc(vcpu, msr_info);
                break;
        case MSR_IA32_CR_PAT:
                if (vmcs_config.vmentry_ctrl & VM_ENTRY_LOAD_IA32_PAT) {
                        if (!kvm_mtrr_valid(vcpu, MSR_IA32_CR_PAT, data))
                                return 1;
                        vmcs_write64(GUEST_IA32_PAT, data);
                        vcpu->arch.pat = data;
                        break;
                }
                ret = kvm_set_msr_common(vcpu, msr_info);
                break;
        case MSR_IA32_TSC_ADJUST:
                ret = kvm_set_msr_common(vcpu, msr_info);
                break;
        case MSR_IA32_FEATURE_CONTROL:
                if (!nested_vmx_allowed(vcpu) ||
                    (to_vmx(vcpu)->nested.msr_ia32_feature_control &
                     FEATURE_CONTROL_LOCKED && !msr_info->host_initiated))
                        return 1;
                vmx->nested.msr_ia32_feature_control = data;
                if (msr_info->host_initiated && data == 0)
                        vmx_leave_nested(vcpu);
                break;
        case MSR_IA32_VMX_BASIC ... MSR_IA32_VMX_VMFUNC:
                return 1; /* they are read-only */
        case MSR_TSC_AUX:
                if (!vmx->rdtscp_enabled)
                        return 1;
                /* Check reserved bit, higher 32 bits should be zero */
                if ((data >> 32) != 0)
                        return 1;
                /* Otherwise falls through */
        default:
                msr = find_msr_entry(vmx, msr_index);
                if (msr) {
                        msr->data = data;
                        if (msr - vmx->guest_msrs < vmx->save_nmsrs) {
                                preempt_disable();
                                kvm_set_shared_msr(msr->index, msr->data,
                                                   msr->mask);
                                preempt_enable();
                        }
                        break;
                }
                ret = kvm_set_msr_common(vcpu, msr_info);
        }

        return ret;
}

static void vmx_cache_reg(struct kvm_vcpu *vcpu, enum kvm_reg reg)
{
        __set_bit(reg, (unsigned long *)&vcpu->arch.regs_avail);
        switch (reg) {
        case VCPU_REGS_RSP:
                vcpu->arch.regs[VCPU_REGS_RSP] = vmcs_readl(GUEST_RSP);
                break;
        case VCPU_REGS_RIP:
                vcpu->arch.regs[VCPU_REGS_RIP] = vmcs_readl(GUEST_RIP);
                break;
        case VCPU_EXREG_PDPTR:
                if (enable_ept)
                        ept_save_pdptrs(vcpu);
                break;
        default:
                break;
        }
}

static __init int cpu_has_kvm_support(void)
{
        return cpu_has_vmx();
}

static __init int vmx_disabled_by_bios(void)
{
        u64 msr;

        rdmsrl(MSR_IA32_FEATURE_CONTROL, msr);
        if (msr & FEATURE_CONTROL_LOCKED) {
                /* launched w/ TXT and VMX disabled */
                if (!(msr & FEATURE_CONTROL_VMXON_ENABLED_INSIDE_SMX)
                        && tboot_enabled())
                        return 1;
                /* launched w/o TXT and VMX only enabled w/ TXT */
                if (!(msr & FEATURE_CONTROL_VMXON_ENABLED_OUTSIDE_SMX)
                        && (msr & FEATURE_CONTROL_VMXON_ENABLED_INSIDE_SMX)
                        && !tboot_enabled()) {
                        printk(KERN_WARNING "kvm: disable TXT in the BIOS or "
                                "activate TXT before enabling KVM\n");
                        return 1;
                }
                /* launched w/o TXT and VMX disabled */
                if (!(msr & FEATURE_CONTROL_VMXON_ENABLED_OUTSIDE_SMX)
                        && !tboot_enabled())
                        return 1;
        }

        return 0;
}

static void kvm_cpu_vmxon(u64 addr)
{
        asm volatile (ASM_VMX_VMXON_RAX
                        : : "a"(&addr), "m"(addr)
                        : "memory", "cc");
}

static int hardware_enable(void)
{
        int cpu = raw_smp_processor_id();
        u64 phys_addr = __pa(per_cpu(vmxarea, cpu));
        u64 old, test_bits;

        if (read_cr4() & X86_CR4_VMXE)
                return -EBUSY;

        INIT_LIST_HEAD(&per_cpu(loaded_vmcss_on_cpu, cpu));

        /*
         * Now we can enable the vmclear operation in kdump
         * since the loaded_vmcss_on_cpu list on this cpu
         * has been initialized.
         *
         * Though the cpu is not in VMX operation now, there
         * is no problem to enable the vmclear operation
         * for the loaded_vmcss_on_cpu list is empty!
         */
        crash_enable_local_vmclear(cpu);

        rdmsrl(MSR_IA32_FEATURE_CONTROL, old);

        test_bits = FEATURE_CONTROL_LOCKED;
        test_bits |= FEATURE_CONTROL_VMXON_ENABLED_OUTSIDE_SMX;
        if (tboot_enabled())
                test_bits |= FEATURE_CONTROL_VMXON_ENABLED_INSIDE_SMX;

        if ((old & test_bits) != test_bits) {
                /* enable and lock */
                wrmsrl(MSR_IA32_FEATURE_CONTROL, old | test_bits);
        }
        write_cr4(read_cr4() | X86_CR4_VMXE); /* FIXME: not cpu hotplug safe */

        if (vmm_exclusive) {
                kvm_cpu_vmxon(phys_addr);
                ept_sync_global();
        }

        native_store_gdt(this_cpu_ptr(&host_gdt));

        return 0;
}

static void vmclear_local_loaded_vmcss(void)
{
        int cpu = raw_smp_processor_id();
        struct loaded_vmcs *v, *n;

        list_for_each_entry_safe(v, n, &per_cpu(loaded_vmcss_on_cpu, cpu),
                                 loaded_vmcss_on_cpu_link)
                __loaded_vmcs_clear(v);
}


/* Just like cpu_vmxoff(), but with the __kvm_handle_fault_on_reboot()
 * tricks.
 */
static void kvm_cpu_vmxoff(void)
{
        asm volatile (__ex(ASM_VMX_VMXOFF) : : : "cc");
}

static void hardware_disable(void)
{
        if (vmm_exclusive) {
                vmclear_local_loaded_vmcss();
                kvm_cpu_vmxoff();
        }
        write_cr4(read_cr4() & ~X86_CR4_VMXE);
}

static __init int adjust_vmx_controls(u32 ctl_min, u32 ctl_opt,
                                      u32 msr, u32 *result)
{
        u32 vmx_msr_low, vmx_msr_high;
        u32 ctl = ctl_min | ctl_opt;

        rdmsr(msr, vmx_msr_low, vmx_msr_high);

        ctl &= vmx_msr_high; /* bit == 0 in high word ==> must be zero */
        ctl |= vmx_msr_low;  /* bit == 1 in low word  ==> must be one  */

        /* Ensure minimum (required) set of control bits are supported. */
        if (ctl_min & ~ctl)
                return -EIO;

        *result = ctl;
        return 0;
}

static __init bool allow_1_setting(u32 msr, u32 ctl)
{
        u32 vmx_msr_low, vmx_msr_high;

        rdmsr(msr, vmx_msr_low, vmx_msr_high);
        return vmx_msr_high & ctl;
}

static __init int setup_vmcs_config(struct vmcs_config *vmcs_conf)
{
        u32 vmx_msr_low, vmx_msr_high;
        u32 min, opt, min2, opt2;
        u32 _pin_based_exec_control = 0;
        u32 _cpu_based_exec_control = 0;
        u32 _cpu_based_2nd_exec_control = 0;
        u32 _vmexit_control = 0;
        u32 _vmentry_control = 0;

        min = CPU_BASED_HLT_EXITING |
#ifdef CONFIG_X86_64
              CPU_BASED_CR8_LOAD_EXITING |
              CPU_BASED_CR8_STORE_EXITING |
#endif
              CPU_BASED_CR3_LOAD_EXITING |
              CPU_BASED_CR3_STORE_EXITING |
              CPU_BASED_USE_IO_BITMAPS |
              CPU_BASED_MOV_DR_EXITING |
              CPU_BASED_USE_TSC_OFFSETING |
              CPU_BASED_MWAIT_EXITING |
              CPU_BASED_MONITOR_EXITING |
              CPU_BASED_INVLPG_EXITING |
              CPU_BASED_RDPMC_EXITING;

        opt = CPU_BASED_TPR_SHADOW |
              CPU_BASED_USE_MSR_BITMAPS |
              CPU_BASED_ACTIVATE_SECONDARY_CONTROLS;
        if (adjust_vmx_controls(min, opt, MSR_IA32_VMX_PROCBASED_CTLS,
                                &_cpu_based_exec_control) < 0)
                return -EIO;
#ifdef CONFIG_X86_64
        if ((_cpu_based_exec_control & CPU_BASED_TPR_SHADOW))
                _cpu_based_exec_control &= ~CPU_BASED_CR8_LOAD_EXITING &
                                           ~CPU_BASED_CR8_STORE_EXITING;
#endif
        if (_cpu_based_exec_control & CPU_BASED_ACTIVATE_SECONDARY_CONTROLS) {
                min2 = 0;
                opt2 = SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES |
                        SECONDARY_EXEC_VIRTUALIZE_X2APIC_MODE |
                        SECONDARY_EXEC_WBINVD_EXITING |
                        SECONDARY_EXEC_ENABLE_VPID |
                        SECONDARY_EXEC_ENABLE_EPT |
                        SECONDARY_EXEC_UNRESTRICTED_GUEST |
                        SECONDARY_EXEC_PAUSE_LOOP_EXITING |
                        SECONDARY_EXEC_RDTSCP |
                        SECONDARY_EXEC_ENABLE_INVPCID |
                        SECONDARY_EXEC_APIC_REGISTER_VIRT |
                        SECONDARY_EXEC_VIRTUAL_INTR_DELIVERY |
                        SECONDARY_EXEC_SHADOW_VMCS;
                if (adjust_vmx_controls(min2, opt2,
                                        MSR_IA32_VMX_PROCBASED_CTLS2,
                                        &_cpu_based_2nd_exec_control) < 0)
                        return -EIO;
        }
#ifndef CONFIG_X86_64
        if (!(_cpu_based_2nd_exec_control &
                                SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES))
                _cpu_based_exec_control &= ~CPU_BASED_TPR_SHADOW;
#endif

        if (!(_cpu_based_exec_control & CPU_BASED_TPR_SHADOW))
                _cpu_based_2nd_exec_control &= ~(
                                SECONDARY_EXEC_APIC_REGISTER_VIRT |
                                SECONDARY_EXEC_VIRTUALIZE_X2APIC_MODE |
                                SECONDARY_EXEC_VIRTUAL_INTR_DELIVERY);

        if (_cpu_based_2nd_exec_control & SECONDARY_EXEC_ENABLE_EPT) {
                /* CR3 accesses and invlpg don't need to cause VM Exits when EPT
                   enabled */
                _cpu_based_exec_control &= ~(CPU_BASED_CR3_LOAD_EXITING |
                                             CPU_BASED_CR3_STORE_EXITING |
                                             CPU_BASED_INVLPG_EXITING);
                rdmsr(MSR_IA32_VMX_EPT_VPID_CAP,
                      vmx_capability.ept, vmx_capability.vpid);
        }

        min = VM_EXIT_SAVE_DEBUG_CONTROLS;
#ifdef CONFIG_X86_64
        min |= VM_EXIT_HOST_ADDR_SPACE_SIZE;
#endif
        opt = VM_EXIT_SAVE_IA32_PAT | VM_EXIT_LOAD_IA32_PAT |
                VM_EXIT_ACK_INTR_ON_EXIT | VM_EXIT_CLEAR_BNDCFGS;
        if (adjust_vmx_controls(min, opt, MSR_IA32_VMX_EXIT_CTLS,
                                &_vmexit_control) < 0)
                return -EIO;

        min = PIN_BASED_EXT_INTR_MASK | PIN_BASED_NMI_EXITING;
        opt = PIN_BASED_VIRTUAL_NMIS | PIN_BASED_POSTED_INTR;
        if (adjust_vmx_controls(min, opt, MSR_IA32_VMX_PINBASED_CTLS,
                                &_pin_based_exec_control) < 0)
                return -EIO;

        if (!(_cpu_based_2nd_exec_control &
                SECONDARY_EXEC_VIRTUAL_INTR_DELIVERY) ||
                !(_vmexit_control & VM_EXIT_ACK_INTR_ON_EXIT))
                _pin_based_exec_control &= ~PIN_BASED_POSTED_INTR;

        min = VM_ENTRY_LOAD_DEBUG_CONTROLS;
        opt = VM_ENTRY_LOAD_IA32_PAT | VM_ENTRY_LOAD_BNDCFGS;
        if (adjust_vmx_controls(min, opt, MSR_IA32_VMX_ENTRY_CTLS,
                                &_vmentry_control) < 0)
                return -EIO;

        rdmsr(MSR_IA32_VMX_BASIC, vmx_msr_low, vmx_msr_high);

        /* IA-32 SDM Vol 3B: VMCS size is never greater than 4kB. */
        if ((vmx_msr_high & 0x1fff) > PAGE_SIZE)
                return -EIO;

#ifdef CONFIG_X86_64
        /* IA-32 SDM Vol 3B: 64-bit CPUs always have VMX_BASIC_MSR[48]==0. */
        if (vmx_msr_high & (1u<<16))
                return -EIO;
#endif

        /* Require Write-Back (WB) memory type for VMCS accesses. */
        if (((vmx_msr_high >> 18) & 15) != 6)
                return -EIO;

        vmcs_conf->size = vmx_msr_high & 0x1fff;
        vmcs_conf->order = get_order(vmcs_config.size);
        vmcs_conf->revision_id = vmx_msr_low;

        vmcs_conf->pin_based_exec_ctrl = _pin_based_exec_control;
        vmcs_conf->cpu_based_exec_ctrl = _cpu_based_exec_control;
        vmcs_conf->cpu_based_2nd_exec_ctrl = _cpu_based_2nd_exec_control;
        vmcs_conf->vmexit_ctrl         = _vmexit_control;
        vmcs_conf->vmentry_ctrl        = _vmentry_control;

        cpu_has_load_ia32_efer =
                allow_1_setting(MSR_IA32_VMX_ENTRY_CTLS,
                                VM_ENTRY_LOAD_IA32_EFER)
                && allow_1_setting(MSR_IA32_VMX_EXIT_CTLS,
                                   VM_EXIT_LOAD_IA32_EFER);

        cpu_has_load_perf_global_ctrl =
                allow_1_setting(MSR_IA32_VMX_ENTRY_CTLS,
                                VM_ENTRY_LOAD_IA32_PERF_GLOBAL_CTRL)
                && allow_1_setting(MSR_IA32_VMX_EXIT_CTLS,
                                   VM_EXIT_LOAD_IA32_PERF_GLOBAL_CTRL);

        /*
         * Some cpus support VM_ENTRY_(LOAD|SAVE)_IA32_PERF_GLOBAL_CTRL
         * but due to arrata below it can't be used. Workaround is to use
         * msr load mechanism to switch IA32_PERF_GLOBAL_CTRL.
         *
         * VM Exit May Incorrectly Clear IA32_PERF_GLOBAL_CTRL [34:32]
         *
         * AAK155             (model 26)
         * AAP115             (model 30)
         * AAT100             (model 37)
         * BC86,AAY89,BD102   (model 44)
         * BA97               (model 46)
         *
         */
        if (cpu_has_load_perf_global_ctrl && boot_cpu_data.x86 == 0x6) {
                switch (boot_cpu_data.x86_model) {
                case 26:
                case 30:
                case 37:
                case 44:
                case 46:
                        cpu_has_load_perf_global_ctrl = false;
                        printk_once(KERN_WARNING"kvm: VM_EXIT_LOAD_IA32_PERF_GLOBAL_CTRL "
                                        "does not work properly. Using workaround\n");
                        break;
                default:
                        break;
                }
        }

        return 0;
}

static struct vmcs *alloc_vmcs_cpu(int cpu)
{
        int node = cpu_to_node(cpu);
        struct page *pages;
        struct vmcs *vmcs;

        pages = alloc_pages_exact_node(node, GFP_KERNEL, vmcs_config.order);
        if (!pages)
                return NULL;
        vmcs = page_address(pages);
        memset(vmcs, 0, vmcs_config.size);
        vmcs->revision_id = vmcs_config.revision_id; /* vmcs revision id */
        return vmcs;
}

static struct vmcs *alloc_vmcs(void)
{
        return alloc_vmcs_cpu(raw_smp_processor_id());
}

static void free_vmcs(struct vmcs *vmcs)
{
        free_pages((unsigned long)vmcs, vmcs_config.order);
}

/*
 * Free a VMCS, but before that VMCLEAR it on the CPU where it was last loaded
 */
static void free_loaded_vmcs(struct loaded_vmcs *loaded_vmcs)
{
        if (!loaded_vmcs->vmcs)
                return;
        loaded_vmcs_clear(loaded_vmcs);
        free_vmcs(loaded_vmcs->vmcs);
        loaded_vmcs->vmcs = NULL;
}

static void free_kvm_area(void)
{
        int cpu;

        for_each_possible_cpu(cpu) {
                free_vmcs(per_cpu(vmxarea, cpu));
                per_cpu(vmxarea, cpu) = NULL;
        }
}

static void init_vmcs_shadow_fields(void)
{
        int i, j;

        /* No checks for read only fields yet */

        for (i = j = 0; i < max_shadow_read_write_fields; i++) {
                switch (shadow_read_write_fields[i]) {
                case GUEST_BNDCFGS:
                        if (!vmx_mpx_supported())
                                continue;
                        break;
                default:
                        break;
                }

                if (j < i)
                        shadow_read_write_fields[j] =
                                shadow_read_write_fields[i];
                j++;
        }
        max_shadow_read_write_fields = j;

        /* shadowed fields guest access without vmexit */
        for (i = 0; i < max_shadow_read_write_fields; i++) {
                clear_bit(shadow_read_write_fields[i],
                          vmx_vmwrite_bitmap);
                clear_bit(shadow_read_write_fields[i],
                          vmx_vmread_bitmap);
        }
        for (i = 0; i < max_shadow_read_only_fields; i++)
                clear_bit(shadow_read_only_fields[i],
                          vmx_vmread_bitmap);
}

static __init int alloc_kvm_area(void)
{
        int cpu;

        for_each_possible_cpu(cpu) {
                struct vmcs *vmcs;

                vmcs = alloc_vmcs_cpu(cpu);
                if (!vmcs) {
                        free_kvm_area();
                        return -ENOMEM;
                }

                per_cpu(vmxarea, cpu) = vmcs;
        }
        return 0;
}

static __init int hardware_setup(void)
{
        if (setup_vmcs_config(&vmcs_config) < 0)
                return -EIO;

        if (boot_cpu_has(X86_FEATURE_NX))
                kvm_enable_efer_bits(EFER_NX);

        if (!cpu_has_vmx_vpid())
                enable_vpid = 0;
        if (!cpu_has_vmx_shadow_vmcs())
                enable_shadow_vmcs = 0;
        if (enable_shadow_vmcs)
                init_vmcs_shadow_fields();

        if (!cpu_has_vmx_ept() ||
            !cpu_has_vmx_ept_4levels()) {
                enable_ept = 0;
                enable_unrestricted_guest = 0;
                enable_ept_ad_bits = 0;
        }

        if (!cpu_has_vmx_ept_ad_bits())
                enable_ept_ad_bits = 0;

        if (!cpu_has_vmx_unrestricted_guest())
                enable_unrestricted_guest = 0;

        if (!cpu_has_vmx_flexpriority()) {
                flexpriority_enabled = 0;

                /*
                 * set_apic_access_page_addr() is used to reload apic access
                 * page upon invalidation.  No need to do anything if the
                 * processor does not have the APIC_ACCESS_ADDR VMCS field.
                 */
                kvm_x86_ops->set_apic_access_page_addr = NULL;
        }

        if (!cpu_has_vmx_tpr_shadow())
                kvm_x86_ops->update_cr8_intercept = NULL;

        if (enable_ept && !cpu_has_vmx_ept_2m_page())
                kvm_disable_largepages();

        if (!cpu_has_vmx_ple())
                ple_gap = 0;

        if (!cpu_has_vmx_apicv())
                enable_apicv = 0;

        if (enable_apicv)
                kvm_x86_ops->update_cr8_intercept = NULL;
        else {
                kvm_x86_ops->hwapic_irr_update = NULL;
                kvm_x86_ops->deliver_posted_interrupt = NULL;
                kvm_x86_ops->sync_pir_to_irr = vmx_sync_pir_to_irr_dummy;
        }

        if (nested)
                nested_vmx_setup_ctls_msrs();

        return alloc_kvm_area();
}

static __exit void hardware_unsetup(void)
{
        free_kvm_area();
}

static bool emulation_required(struct kvm_vcpu *vcpu)
{
        return emulate_invalid_guest_state && !guest_state_valid(vcpu);
}

static void fix_pmode_seg(struct kvm_vcpu *vcpu, int seg,
                struct kvm_segment *save)
{
        if (!emulate_invalid_guest_state) {
                /*
                 * CS and SS RPL should be equal during guest entry according
                 * to VMX spec, but in reality it is not always so. Since vcpu
                 * is in the middle of the transition from real mode to
                 * protected mode it is safe to assume that RPL 0 is a good
                 * default value.
                 */
                if (seg == VCPU_SREG_CS || seg == VCPU_SREG_SS)
                        save->selector &= ~SELECTOR_RPL_MASK;
                save->dpl = save->selector & SELECTOR_RPL_MASK;
                save->s = 1;
        }
        vmx_set_segment(vcpu, save, seg);
}

static void enter_pmode(struct kvm_vcpu *vcpu)
{
        unsigned long flags;
        struct vcpu_vmx *vmx = to_vmx(vcpu);

        /*
         * Update real mode segment cache. It may be not up-to-date if sement
         * register was written while vcpu was in a guest mode.
         */
        vmx_get_segment(vcpu, &vmx->rmode.segs[VCPU_SREG_ES], VCPU_SREG_ES);
        vmx_get_segment(vcpu, &vmx->rmode.segs[VCPU_SREG_DS], VCPU_SREG_DS);
        vmx_get_segment(vcpu, &vmx->rmode.segs[VCPU_SREG_FS], VCPU_SREG_FS);
        vmx_get_segment(vcpu, &vmx->rmode.segs[VCPU_SREG_GS], VCPU_SREG_GS);
        vmx_get_segment(vcpu, &vmx->rmode.segs[VCPU_SREG_SS], VCPU_SREG_SS);
        vmx_get_segment(vcpu, &vmx->rmode.segs[VCPU_SREG_CS], VCPU_SREG_CS);

        vmx->rmode.vm86_active = 0;

        vmx_segment_cache_clear(vmx);

        vmx_set_segment(vcpu, &vmx->rmode.segs[VCPU_SREG_TR], VCPU_SREG_TR);

        flags = vmcs_readl(GUEST_RFLAGS);
        flags &= RMODE_GUEST_OWNED_EFLAGS_BITS;
        flags |= vmx->rmode.save_rflags & ~RMODE_GUEST_OWNED_EFLAGS_BITS;
        vmcs_writel(GUEST_RFLAGS, flags);

        vmcs_writel(GUEST_CR4, (vmcs_readl(GUEST_CR4) & ~X86_CR4_VME) |
                        (vmcs_readl(CR4_READ_SHADOW) & X86_CR4_VME));

        update_exception_bitmap(vcpu);

        fix_pmode_seg(vcpu, VCPU_SREG_CS, &vmx->rmode.segs[VCPU_SREG_CS]);
        fix_pmode_seg(vcpu, VCPU_SREG_SS, &vmx->rmode.segs[VCPU_SREG_SS]);
        fix_pmode_seg(vcpu, VCPU_SREG_ES, &vmx->rmode.segs[VCPU_SREG_ES]);
        fix_pmode_seg(vcpu, VCPU_SREG_DS, &vmx->rmode.segs[VCPU_SREG_DS]);
        fix_pmode_seg(vcpu, VCPU_SREG_FS, &vmx->rmode.segs[VCPU_SREG_FS]);
        fix_pmode_seg(vcpu, VCPU_SREG_GS, &vmx->rmode.segs[VCPU_SREG_GS]);
}

static void fix_rmode_seg(int seg, struct kvm_segment *save)
{
        const struct kvm_vmx_segment_field *sf = &kvm_vmx_segment_fields[seg];
        struct kvm_segment var = *save;

        var.dpl = 0x3;
        if (seg == VCPU_SREG_CS)
                var.type = 0x3;

        if (!emulate_invalid_guest_state) {
                var.selector = var.base >> 4;
                var.base = var.base & 0xffff0;
                var.limit = 0xffff;
                var.g = 0;
                var.db = 0;
                var.present = 1;
                var.s = 1;
                var.l = 0;
                var.unusable = 0;
                var.type = 0x3;
                var.avl = 0;
                if (save->base & 0xf)
                        printk_once(KERN_WARNING "kvm: segment base is not "
                                        "paragraph aligned when entering "
                                        "protected mode (seg=%d)", seg);
        }

        vmcs_write16(sf->selector, var.selector);
        vmcs_write32(sf->base, var.base);
        vmcs_write32(sf->limit, var.limit);
        vmcs_write32(sf->ar_bytes, vmx_segment_access_rights(&var));
}

static void enter_rmode(struct kvm_vcpu *vcpu)
{
        unsigned long flags;
        struct vcpu_vmx *vmx = to_vmx(vcpu);

        vmx_get_segment(vcpu, &vmx->rmode.segs[VCPU_SREG_TR], VCPU_SREG_TR);
        vmx_get_segment(vcpu, &vmx->rmode.segs[VCPU_SREG_ES], VCPU_SREG_ES);
        vmx_get_segment(vcpu, &vmx->rmode.segs[VCPU_SREG_DS], VCPU_SREG_DS);
        vmx_get_segment(vcpu, &vmx->rmode.segs[VCPU_SREG_FS], VCPU_SREG_FS);
        vmx_get_segment(vcpu, &vmx->rmode.segs[VCPU_SREG_GS], VCPU_SREG_GS);
        vmx_get_segment(vcpu, &vmx->rmode.segs[VCPU_SREG_SS], VCPU_SREG_SS);
        vmx_get_segment(vcpu, &vmx->rmode.segs[VCPU_SREG_CS], VCPU_SREG_CS);

        vmx->rmode.vm86_active = 1;

        /*
         * Very old userspace does not call KVM_SET_TSS_ADDR before entering
         * vcpu. Warn the user that an update is overdue.
         */
        if (!vcpu->kvm->arch.tss_addr)
                printk_once(KERN_WARNING "kvm: KVM_SET_TSS_ADDR need to be "
                             "called before entering vcpu\n");

        vmx_segment_cache_clear(vmx);

        vmcs_writel(GUEST_TR_BASE, vcpu->kvm->arch.tss_addr);
        vmcs_write32(GUEST_TR_LIMIT, RMODE_TSS_SIZE - 1);
        vmcs_write32(GUEST_TR_AR_BYTES, 0x008b);

        flags = vmcs_readl(GUEST_RFLAGS);
        vmx->rmode.save_rflags = flags;

        flags |= X86_EFLAGS_IOPL | X86_EFLAGS_VM;

        vmcs_writel(GUEST_RFLAGS, flags);
        vmcs_writel(GUEST_CR4, vmcs_readl(GUEST_CR4) | X86_CR4_VME);
        update_exception_bitmap(vcpu);

        fix_rmode_seg(VCPU_SREG_SS, &vmx->rmode.segs[VCPU_SREG_SS]);
        fix_rmode_seg(VCPU_SREG_CS, &vmx->rmode.segs[VCPU_SREG_CS]);
        fix_rmode_seg(VCPU_SREG_ES, &vmx->rmode.segs[VCPU_SREG_ES]);
        fix_rmode_seg(VCPU_SREG_DS, &vmx->rmode.segs[VCPU_SREG_DS]);
        fix_rmode_seg(VCPU_SREG_GS, &vmx->rmode.segs[VCPU_SREG_GS]);
        fix_rmode_seg(VCPU_SREG_FS, &vmx->rmode.segs[VCPU_SREG_FS]);

        kvm_mmu_reset_context(vcpu);
}

static void vmx_set_efer(struct kvm_vcpu *vcpu, u64 efer)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);
        struct shared_msr_entry *msr = find_msr_entry(vmx, MSR_EFER);

        if (!msr)
                return;

        /*
         * Force kernel_gs_base reloading before EFER changes, as control
         * of this msr depends on is_long_mode().
         */
        vmx_load_host_state(to_vmx(vcpu));
        vcpu->arch.efer = efer;
        if (efer & EFER_LMA) {
                vm_entry_controls_setbit(to_vmx(vcpu), VM_ENTRY_IA32E_MODE);
                msr->data = efer;
        } else {
                vm_entry_controls_clearbit(to_vmx(vcpu), VM_ENTRY_IA32E_MODE);

                msr->data = efer & ~EFER_LME;
        }
        setup_msrs(vmx);
}

#ifdef CONFIG_X86_64

static void enter_lmode(struct kvm_vcpu *vcpu)
{
        u32 guest_tr_ar;

        vmx_segment_cache_clear(to_vmx(vcpu));

        guest_tr_ar = vmcs_read32(GUEST_TR_AR_BYTES);
        if ((guest_tr_ar & AR_TYPE_MASK) != AR_TYPE_BUSY_64_TSS) {
                pr_debug_ratelimited("%s: tss fixup for long mode. \n",
                                     __func__);
                vmcs_write32(GUEST_TR_AR_BYTES,
                             (guest_tr_ar & ~AR_TYPE_MASK)
                             | AR_TYPE_BUSY_64_TSS);
        }
        vmx_set_efer(vcpu, vcpu->arch.efer | EFER_LMA);
}

static void exit_lmode(struct kvm_vcpu *vcpu)
{
        vm_entry_controls_clearbit(to_vmx(vcpu), VM_ENTRY_IA32E_MODE);
        vmx_set_efer(vcpu, vcpu->arch.efer & ~EFER_LMA);
}

#endif

static void vmx_flush_tlb(struct kvm_vcpu *vcpu)
{
        vpid_sync_context(to_vmx(vcpu));
        if (enable_ept) {
                if (!VALID_PAGE(vcpu->arch.mmu.root_hpa))
                        return;
                ept_sync_context(construct_eptp(vcpu->arch.mmu.root_hpa));
        }
}

static void vmx_decache_cr0_guest_bits(struct kvm_vcpu *vcpu)
{
        ulong cr0_guest_owned_bits = vcpu->arch.cr0_guest_owned_bits;

        vcpu->arch.cr0 &= ~cr0_guest_owned_bits;
        vcpu->arch.cr0 |= vmcs_readl(GUEST_CR0) & cr0_guest_owned_bits;
}

static void vmx_decache_cr3(struct kvm_vcpu *vcpu)
{
        if (enable_ept && is_paging(vcpu))
                vcpu->arch.cr3 = vmcs_readl(GUEST_CR3);
        __set_bit(VCPU_EXREG_CR3, (ulong *)&vcpu->arch.regs_avail);
}

static void vmx_decache_cr4_guest_bits(struct kvm_vcpu *vcpu)
{
        ulong cr4_guest_owned_bits = vcpu->arch.cr4_guest_owned_bits;

        vcpu->arch.cr4 &= ~cr4_guest_owned_bits;
        vcpu->arch.cr4 |= vmcs_readl(GUEST_CR4) & cr4_guest_owned_bits;
}

static void ept_load_pdptrs(struct kvm_vcpu *vcpu)
{
        struct kvm_mmu *mmu = vcpu->arch.walk_mmu;

        if (!test_bit(VCPU_EXREG_PDPTR,
                      (unsigned long *)&vcpu->arch.regs_dirty))
                return;

        if (is_paging(vcpu) && is_pae(vcpu) && !is_long_mode(vcpu)) {
                vmcs_write64(GUEST_PDPTR0, mmu->pdptrs[0]);
                vmcs_write64(GUEST_PDPTR1, mmu->pdptrs[1]);
                vmcs_write64(GUEST_PDPTR2, mmu->pdptrs[2]);
                vmcs_write64(GUEST_PDPTR3, mmu->pdptrs[3]);
        }
}

static void ept_save_pdptrs(struct kvm_vcpu *vcpu)
{
        struct kvm_mmu *mmu = vcpu->arch.walk_mmu;

        if (is_paging(vcpu) && is_pae(vcpu) && !is_long_mode(vcpu)) {
                mmu->pdptrs[0] = vmcs_read64(GUEST_PDPTR0);
                mmu->pdptrs[1] = vmcs_read64(GUEST_PDPTR1);
                mmu->pdptrs[2] = vmcs_read64(GUEST_PDPTR2);
                mmu->pdptrs[3] = vmcs_read64(GUEST_PDPTR3);
        }

        __set_bit(VCPU_EXREG_PDPTR,
                  (unsigned long *)&vcpu->arch.regs_avail);
        __set_bit(VCPU_EXREG_PDPTR,
                  (unsigned long *)&vcpu->arch.regs_dirty);
}

static int vmx_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4);

static void ept_update_paging_mode_cr0(unsigned long *hw_cr0,
                                        unsigned long cr0,
                                        struct kvm_vcpu *vcpu)
{
        if (!test_bit(VCPU_EXREG_CR3, (ulong *)&vcpu->arch.regs_avail))
                vmx_decache_cr3(vcpu);
        if (!(cr0 & X86_CR0_PG)) {
                /* From paging/starting to nonpaging */
                vmcs_write32(CPU_BASED_VM_EXEC_CONTROL,
                             vmcs_read32(CPU_BASED_VM_EXEC_CONTROL) |
                             (CPU_BASED_CR3_LOAD_EXITING |
                              CPU_BASED_CR3_STORE_EXITING));
                vcpu->arch.cr0 = cr0;
                vmx_set_cr4(vcpu, kvm_read_cr4(vcpu));
        } else if (!is_paging(vcpu)) {
                /* From nonpaging to paging */
                vmcs_write32(CPU_BASED_VM_EXEC_CONTROL,
                             vmcs_read32(CPU_BASED_VM_EXEC_CONTROL) &
                             ~(CPU_BASED_CR3_LOAD_EXITING |
                               CPU_BASED_CR3_STORE_EXITING));
                vcpu->arch.cr0 = cr0;
                vmx_set_cr4(vcpu, kvm_read_cr4(vcpu));
        }

        if (!(cr0 & X86_CR0_WP))
                *hw_cr0 &= ~X86_CR0_WP;
}

static void vmx_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);
        unsigned long hw_cr0;

        hw_cr0 = (cr0 & ~KVM_GUEST_CR0_MASK);
        if (enable_unrestricted_guest)
                hw_cr0 |= KVM_VM_CR0_ALWAYS_ON_UNRESTRICTED_GUEST;
        else {
                hw_cr0 |= KVM_VM_CR0_ALWAYS_ON;

                if (vmx->rmode.vm86_active && (cr0 & X86_CR0_PE))
                        enter_pmode(vcpu);

                if (!vmx->rmode.vm86_active && !(cr0 & X86_CR0_PE))
                        enter_rmode(vcpu);
        }

#ifdef CONFIG_X86_64
        if (vcpu->arch.efer & EFER_LME) {
                if (!is_paging(vcpu) && (cr0 & X86_CR0_PG))
                        enter_lmode(vcpu);
                if (is_paging(vcpu) && !(cr0 & X86_CR0_PG))
                        exit_lmode(vcpu);
        }
#endif

        if (enable_ept)
                ept_update_paging_mode_cr0(&hw_cr0, cr0, vcpu);

        if (!vcpu->fpu_active)
                hw_cr0 |= X86_CR0_TS | X86_CR0_MP;

        vmcs_writel(CR0_READ_SHADOW, cr0);
        vmcs_writel(GUEST_CR0, hw_cr0);
        vcpu->arch.cr0 = cr0;

        /* depends on vcpu->arch.cr0 to be set to a new value */
        vmx->emulation_required = emulation_required(vcpu);
}

static u64 construct_eptp(unsigned long root_hpa)
{
        u64 eptp;

        /* TODO write the value reading from MSR */
        eptp = VMX_EPT_DEFAULT_MT |
                VMX_EPT_DEFAULT_GAW << VMX_EPT_GAW_EPTP_SHIFT;
        if (enable_ept_ad_bits)
                eptp |= VMX_EPT_AD_ENABLE_BIT;
        eptp |= (root_hpa & PAGE_MASK);

        return eptp;
}

static void vmx_set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3)
{
        unsigned long guest_cr3;
        u64 eptp;

        guest_cr3 = cr3;
        if (enable_ept) {
                eptp = construct_eptp(cr3);
                vmcs_write64(EPT_POINTER, eptp);
                if (is_paging(vcpu) || is_guest_mode(vcpu))
                        guest_cr3 = kvm_read_cr3(vcpu);
                else
                        guest_cr3 = vcpu->kvm->arch.ept_identity_map_addr;
                ept_load_pdptrs(vcpu);
        }

        vmx_flush_tlb(vcpu);
        vmcs_writel(GUEST_CR3, guest_cr3);
}

static int vmx_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)
{
        unsigned long hw_cr4 = cr4 | (to_vmx(vcpu)->rmode.vm86_active ?
                    KVM_RMODE_VM_CR4_ALWAYS_ON : KVM_PMODE_VM_CR4_ALWAYS_ON);

        if (cr4 & X86_CR4_VMXE) {
                /*
                 * To use VMXON (and later other VMX instructions), a guest
                 * must first be able to turn on cr4.VMXE (see handle_vmon()).
                 * So basically the check on whether to allow nested VMX
                 * is here.
                 */
                if (!nested_vmx_allowed(vcpu))
                        return 1;
        }
        if (to_vmx(vcpu)->nested.vmxon &&
            ((cr4 & VMXON_CR4_ALWAYSON) != VMXON_CR4_ALWAYSON))
                return 1;

        vcpu->arch.cr4 = cr4;
        if (enable_ept) {
                if (!is_paging(vcpu)) {
                        hw_cr4 &= ~X86_CR4_PAE;
                        hw_cr4 |= X86_CR4_PSE;
                        /*
                         * SMEP/SMAP is disabled if CPU is in non-paging mode
                         * in hardware. However KVM always uses paging mode to
                         * emulate guest non-paging mode with TDP.
                         * To emulate this behavior, SMEP/SMAP needs to be
                         * manually disabled when guest switches to non-paging
                         * mode.
                         */
                        hw_cr4 &= ~(X86_CR4_SMEP | X86_CR4_SMAP);
                } else if (!(cr4 & X86_CR4_PAE)) {
                        hw_cr4 &= ~X86_CR4_PAE;
                }
        }

        vmcs_writel(CR4_READ_SHADOW, cr4);
        vmcs_writel(GUEST_CR4, hw_cr4);
        return 0;
}

static void vmx_get_segment(struct kvm_vcpu *vcpu,
                            struct kvm_segment *var, int seg)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);
        u32 ar;

        if (vmx->rmode.vm86_active && seg != VCPU_SREG_LDTR) {
                *var = vmx->rmode.segs[seg];
                if (seg == VCPU_SREG_TR
                    || var->selector == vmx_read_guest_seg_selector(vmx, seg))
                        return;
                var->base = vmx_read_guest_seg_base(vmx, seg);
                var->selector = vmx_read_guest_seg_selector(vmx, seg);
                return;
        }
        var->base = vmx_read_guest_seg_base(vmx, seg);
        var->limit = vmx_read_guest_seg_limit(vmx, seg);
        var->selector = vmx_read_guest_seg_selector(vmx, seg);
        ar = vmx_read_guest_seg_ar(vmx, seg);
        var->unusable = (ar >> 16) & 1;
        var->type = ar & 15;
        var->s = (ar >> 4) & 1;
        var->dpl = (ar >> 5) & 3;
        /*
         * Some userspaces do not preserve unusable property. Since usable
         * segment has to be present according to VMX spec we can use present
         * property to amend userspace bug by making unusable segment always
         * nonpresent. vmx_segment_access_rights() already marks nonpresent
         * segment as unusable.
         */
        var->present = !var->unusable;
        var->avl = (ar >> 12) & 1;
        var->l = (ar >> 13) & 1;
        var->db = (ar >> 14) & 1;
        var->g = (ar >> 15) & 1;
}

static u64 vmx_get_segment_base(struct kvm_vcpu *vcpu, int seg)
{
        struct kvm_segment s;

        if (to_vmx(vcpu)->rmode.vm86_active) {
                vmx_get_segment(vcpu, &s, seg);
                return s.base;
        }
        return vmx_read_guest_seg_base(to_vmx(vcpu), seg);
}

static int vmx_get_cpl(struct kvm_vcpu *vcpu)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);

        if (unlikely(vmx->rmode.vm86_active))
                return 0;
        else {
                int ar = vmx_read_guest_seg_ar(vmx, VCPU_SREG_SS);
                return AR_DPL(ar);
        }
}

static u32 vmx_segment_access_rights(struct kvm_segment *var)
{
        u32 ar;

        if (var->unusable || !var->present)
                ar = 1 << 16;
        else {
                ar = var->type & 15;
                ar |= (var->s & 1) << 4;
                ar |= (var->dpl & 3) << 5;
                ar |= (var->present & 1) << 7;
                ar |= (var->avl & 1) << 12;
                ar |= (var->l & 1) << 13;
                ar |= (var->db & 1) << 14;
                ar |= (var->g & 1) << 15;
        }

        return ar;
}

static void vmx_set_segment(struct kvm_vcpu *vcpu,
                            struct kvm_segment *var, int seg)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);
        const struct kvm_vmx_segment_field *sf = &kvm_vmx_segment_fields[seg];

        vmx_segment_cache_clear(vmx);

        if (vmx->rmode.vm86_active && seg != VCPU_SREG_LDTR) {
                vmx->rmode.segs[seg] = *var;
                if (seg == VCPU_SREG_TR)
                        vmcs_write16(sf->selector, var->selector);
                else if (var->s)
                        fix_rmode_seg(seg, &vmx->rmode.segs[seg]);
                goto out;
        }

        vmcs_writel(sf->base, var->base);
        vmcs_write32(sf->limit, var->limit);
        vmcs_write16(sf->selector, var->selector);

        /*
         *   Fix the "Accessed" bit in AR field of segment registers for older
         * qemu binaries.
         *   IA32 arch specifies that at the time of processor reset the
         * "Accessed" bit in the AR field of segment registers is 1. And qemu
         * is setting it to 0 in the userland code. This causes invalid guest
         * state vmexit when "unrestricted guest" mode is turned on.
         *    Fix for this setup issue in cpu_reset is being pushed in the qemu
         * tree. Newer qemu binaries with that qemu fix would not need this
         * kvm hack.
         */
        if (enable_unrestricted_guest && (seg != VCPU_SREG_LDTR))
                var->type |= 0x1; /* Accessed */

        vmcs_write32(sf->ar_bytes, vmx_segment_access_rights(var));

out:
        vmx->emulation_required = emulation_required(vcpu);
}

static void vmx_get_cs_db_l_bits(struct kvm_vcpu *vcpu, int *db, int *l)
{
        u32 ar = vmx_read_guest_seg_ar(to_vmx(vcpu), VCPU_SREG_CS);

        *db = (ar >> 14) & 1;
        *l = (ar >> 13) & 1;
}

static void vmx_get_idt(struct kvm_vcpu *vcpu, struct desc_ptr *dt)
{
        dt->size = vmcs_read32(GUEST_IDTR_LIMIT);
        dt->address = vmcs_readl(GUEST_IDTR_BASE);
}

static void vmx_set_idt(struct kvm_vcpu *vcpu, struct desc_ptr *dt)
{
        vmcs_write32(GUEST_IDTR_LIMIT, dt->size);
        vmcs_writel(GUEST_IDTR_BASE, dt->address);
}

static void vmx_get_gdt(struct kvm_vcpu *vcpu, struct desc_ptr *dt)
{
        dt->size = vmcs_read32(GUEST_GDTR_LIMIT);
        dt->address = vmcs_readl(GUEST_GDTR_BASE);
}

static void vmx_set_gdt(struct kvm_vcpu *vcpu, struct desc_ptr *dt)
{
        vmcs_write32(GUEST_GDTR_LIMIT, dt->size);
        vmcs_writel(GUEST_GDTR_BASE, dt->address);
}

static bool rmode_segment_valid(struct kvm_vcpu *vcpu, int seg)
{
        struct kvm_segment var;
        u32 ar;

        vmx_get_segment(vcpu, &var, seg);
        var.dpl = 0x3;
        if (seg == VCPU_SREG_CS)
                var.type = 0x3;
        ar = vmx_segment_access_rights(&var);

        if (var.base != (var.selector << 4))
                return false;
        if (var.limit != 0xffff)
                return false;
        if (ar != 0xf3)
                return false;

        return true;
}

static bool code_segment_valid(struct kvm_vcpu *vcpu)
{
        struct kvm_segment cs;
        unsigned int cs_rpl;

        vmx_get_segment(vcpu, &cs, VCPU_SREG_CS);
        cs_rpl = cs.selector & SELECTOR_RPL_MASK;

        if (cs.unusable)
                return false;
        if (~cs.type & (AR_TYPE_CODE_MASK|AR_TYPE_ACCESSES_MASK))
                return false;
        if (!cs.s)
                return false;
        if (cs.type & AR_TYPE_WRITEABLE_MASK) {
                if (cs.dpl > cs_rpl)
                        return false;
        } else {
                if (cs.dpl != cs_rpl)
                        return false;
        }
        if (!cs.present)
                return false;

        /* TODO: Add Reserved field check, this'll require a new member in the kvm_segment_field structure */
        return true;
}

static bool stack_segment_valid(struct kvm_vcpu *vcpu)
{
        struct kvm_segment ss;
        unsigned int ss_rpl;

        vmx_get_segment(vcpu, &ss, VCPU_SREG_SS);
        ss_rpl = ss.selector & SELECTOR_RPL_MASK;

        if (ss.unusable)
                return true;
        if (ss.type != 3 && ss.type != 7)
                return false;
        if (!ss.s)
                return false;
        if (ss.dpl != ss_rpl) /* DPL != RPL */
                return false;
        if (!ss.present)
                return false;

        return true;
}

static bool data_segment_valid(struct kvm_vcpu *vcpu, int seg)
{
        struct kvm_segment var;
        unsigned int rpl;

        vmx_get_segment(vcpu, &var, seg);
        rpl = var.selector & SELECTOR_RPL_MASK;

        if (var.unusable)
                return true;
        if (!var.s)
                return false;
        if (!var.present)
                return false;
        if (~var.type & (AR_TYPE_CODE_MASK|AR_TYPE_WRITEABLE_MASK)) {
                if (var.dpl < rpl) /* DPL < RPL */
                        return false;
        }

        /* TODO: Add other members to kvm_segment_field to allow checking for other access
         * rights flags
         */
        return true;
}

static bool tr_valid(struct kvm_vcpu *vcpu)
{
        struct kvm_segment tr;

        vmx_get_segment(vcpu, &tr, VCPU_SREG_TR);

        if (tr.unusable)
                return false;
        if (tr.selector & SELECTOR_TI_MASK)     /* TI = 1 */
                return false;
        if (tr.type != 3 && tr.type != 11) /* TODO: Check if guest is in IA32e mode */
                return false;
        if (!tr.present)
                return false;

        return true;
}

static bool ldtr_valid(struct kvm_vcpu *vcpu)
{
        struct kvm_segment ldtr;

        vmx_get_segment(vcpu, &ldtr, VCPU_SREG_LDTR);

        if (ldtr.unusable)
                return true;
        if (ldtr.selector & SELECTOR_TI_MASK)   /* TI = 1 */
                return false;
        if (ldtr.type != 2)
                return false;
        if (!ldtr.present)
                return false;

        return true;
}

static bool cs_ss_rpl_check(struct kvm_vcpu *vcpu)
{
        struct kvm_segment cs, ss;

        vmx_get_segment(vcpu, &cs, VCPU_SREG_CS);
        vmx_get_segment(vcpu, &ss, VCPU_SREG_SS);

        return ((cs.selector & SELECTOR_RPL_MASK) ==
                 (ss.selector & SELECTOR_RPL_MASK));
}

/*
 * Check if guest state is valid. Returns true if valid, false if
 * not.
 * We assume that registers are always usable
 */
static bool guest_state_valid(struct kvm_vcpu *vcpu)
{
        if (enable_unrestricted_guest)
                return true;

        /* real mode guest state checks */
        if (!is_protmode(vcpu) || (vmx_get_rflags(vcpu) & X86_EFLAGS_VM)) {
                if (!rmode_segment_valid(vcpu, VCPU_SREG_CS))
                        return false;
                if (!rmode_segment_valid(vcpu, VCPU_SREG_SS))
                        return false;
                if (!rmode_segment_valid(vcpu, VCPU_SREG_DS))
                        return false;
                if (!rmode_segment_valid(vcpu, VCPU_SREG_ES))
                        return false;
                if (!rmode_segment_valid(vcpu, VCPU_SREG_FS))
                        return false;
                if (!rmode_segment_valid(vcpu, VCPU_SREG_GS))
                        return false;
        } else {
        /* protected mode guest state checks */
                if (!cs_ss_rpl_check(vcpu))
                        return false;
                if (!code_segment_valid(vcpu))
                        return false;
                if (!stack_segment_valid(vcpu))
                        return false;
                if (!data_segment_valid(vcpu, VCPU_SREG_DS))
                        return false;
                if (!data_segment_valid(vcpu, VCPU_SREG_ES))
                        return false;
                if (!data_segment_valid(vcpu, VCPU_SREG_FS))
                        return false;
                if (!data_segment_valid(vcpu, VCPU_SREG_GS))
                        return false;
                if (!tr_valid(vcpu))
                        return false;
                if (!ldtr_valid(vcpu))
                        return false;
        }
        /* TODO:
         * - Add checks on RIP
         * - Add checks on RFLAGS
         */

        return true;
}

static int init_rmode_tss(struct kvm *kvm)
{
        gfn_t fn;
        u16 data = 0;
        int idx, r;

        idx = srcu_read_lock(&kvm->srcu);
        fn = kvm->arch.tss_addr >> PAGE_SHIFT;
        r = kvm_clear_guest_page(kvm, fn, 0, PAGE_SIZE);
        if (r < 0)
                goto out;
        data = TSS_BASE_SIZE + TSS_REDIRECTION_SIZE;
        r = kvm_write_guest_page(kvm, fn++, &data,
                        TSS_IOPB_BASE_OFFSET, sizeof(u16));
        if (r < 0)
                goto out;
        r = kvm_clear_guest_page(kvm, fn++, 0, PAGE_SIZE);
        if (r < 0)
                goto out;
        r = kvm_clear_guest_page(kvm, fn, 0, PAGE_SIZE);
        if (r < 0)
                goto out;
        data = ~0;
        r = kvm_write_guest_page(kvm, fn, &data,
                                 RMODE_TSS_SIZE - 2 * PAGE_SIZE - 1,
                                 sizeof(u8));
out:
        srcu_read_unlock(&kvm->srcu, idx);
        return r;
}

static int init_rmode_identity_map(struct kvm *kvm)
{
        int i, idx, r = 0;
        pfn_t identity_map_pfn;
        u32 tmp;

        if (!enable_ept)
                return 0;

        /* Protect kvm->arch.ept_identity_pagetable_done. */
        mutex_lock(&kvm->slots_lock);

        if (likely(kvm->arch.ept_identity_pagetable_done))
                goto out2;

        identity_map_pfn = kvm->arch.ept_identity_map_addr >> PAGE_SHIFT;

        r = alloc_identity_pagetable(kvm);
        if (r < 0)
                goto out2;

        idx = srcu_read_lock(&kvm->srcu);
        r = kvm_clear_guest_page(kvm, identity_map_pfn, 0, PAGE_SIZE);
        if (r < 0)
                goto out;
        /* Set up identity-mapping pagetable for EPT in real mode */
        for (i = 0; i < PT32_ENT_PER_PAGE; i++) {
                tmp = (i << 22) + (_PAGE_PRESENT | _PAGE_RW | _PAGE_USER |
                        _PAGE_ACCESSED | _PAGE_DIRTY | _PAGE_PSE);
                r = kvm_write_guest_page(kvm, identity_map_pfn,
                                &tmp, i * sizeof(tmp), sizeof(tmp));
                if (r < 0)
                        goto out;
        }
        kvm->arch.ept_identity_pagetable_done = true;

out:
        srcu_read_unlock(&kvm->srcu, idx);

out2:
        mutex_unlock(&kvm->slots_lock);
        return r;
}

static void seg_setup(int seg)
{
        const struct kvm_vmx_segment_field *sf = &kvm_vmx_segment_fields[seg];
        unsigned int ar;

        vmcs_write16(sf->selector, 0);
        vmcs_writel(sf->base, 0);
        vmcs_write32(sf->limit, 0xffff);
        ar = 0x93;
        if (seg == VCPU_SREG_CS)
                ar |= 0x08; /* code segment */

        vmcs_write32(sf->ar_bytes, ar);
}

static int alloc_apic_access_page(struct kvm *kvm)
{
        struct page *page;
        struct kvm_userspace_memory_region kvm_userspace_mem;
        int r = 0;

        mutex_lock(&kvm->slots_lock);
        if (kvm->arch.apic_access_page_done)
                goto out;
        kvm_userspace_mem.slot = APIC_ACCESS_PAGE_PRIVATE_MEMSLOT;
        kvm_userspace_mem.flags = 0;
        kvm_userspace_mem.guest_phys_addr = APIC_DEFAULT_PHYS_BASE;
        kvm_userspace_mem.memory_size = PAGE_SIZE;
        r = __kvm_set_memory_region(kvm, &kvm_userspace_mem);
        if (r)
                goto out;

        page = gfn_to_page(kvm, APIC_DEFAULT_PHYS_BASE >> PAGE_SHIFT);
        if (is_error_page(page)) {
                r = -EFAULT;
                goto out;
        }

        /*
         * Do not pin the page in memory, so that memory hot-unplug
         * is able to migrate it.
         */
        put_page(page);
        kvm->arch.apic_access_page_done = true;
out:
        mutex_unlock(&kvm->slots_lock);
        return r;
}

static int alloc_identity_pagetable(struct kvm *kvm)
{
        /* Called with kvm->slots_lock held. */

        struct kvm_userspace_memory_region kvm_userspace_mem;
        int r = 0;

        BUG_ON(kvm->arch.ept_identity_pagetable_done);

        kvm_userspace_mem.slot = IDENTITY_PAGETABLE_PRIVATE_MEMSLOT;
        kvm_userspace_mem.flags = 0;
        kvm_userspace_mem.guest_phys_addr =
                kvm->arch.ept_identity_map_addr;
        kvm_userspace_mem.memory_size = PAGE_SIZE;
        r = __kvm_set_memory_region(kvm, &kvm_userspace_mem);

        return r;
}

static void allocate_vpid(struct vcpu_vmx *vmx)
{
        int vpid;

        vmx->vpid = 0;
        if (!enable_vpid)
                return;
        spin_lock(&vmx_vpid_lock);
        vpid = find_first_zero_bit(vmx_vpid_bitmap, VMX_NR_VPIDS);
        if (vpid < VMX_NR_VPIDS) {
                vmx->vpid = vpid;
                __set_bit(vpid, vmx_vpid_bitmap);
        }
        spin_unlock(&vmx_vpid_lock);
}

static void free_vpid(struct vcpu_vmx *vmx)
{
        if (!enable_vpid)
                return;
        spin_lock(&vmx_vpid_lock);
        if (vmx->vpid != 0)
                __clear_bit(vmx->vpid, vmx_vpid_bitmap);
        spin_unlock(&vmx_vpid_lock);
}

#define MSR_TYPE_R      1
#define MSR_TYPE_W      2
static void __vmx_disable_intercept_for_msr(unsigned long *msr_bitmap,
                                                u32 msr, int type)
{
        int f = sizeof(unsigned long);

        if (!cpu_has_vmx_msr_bitmap())
                return;

        /*
         * See Intel PRM Vol. 3, 20.6.9 (MSR-Bitmap Address). Early manuals
         * have the write-low and read-high bitmap offsets the wrong way round.
         * We can control MSRs 0x00000000-0x00001fff and 0xc0000000-0xc0001fff.
         */
        if (msr <= 0x1fff) {
                if (type & MSR_TYPE_R)
                        /* read-low */
                        __clear_bit(msr, msr_bitmap + 0x000 / f);

                if (type & MSR_TYPE_W)
                        /* write-low */
                        __clear_bit(msr, msr_bitmap + 0x800 / f);

        } else if ((msr >= 0xc0000000) && (msr <= 0xc0001fff)) {
                msr &= 0x1fff;
                if (type & MSR_TYPE_R)
                        /* read-high */
                        __clear_bit(msr, msr_bitmap + 0x400 / f);

                if (type & MSR_TYPE_W)
                        /* write-high */
                        __clear_bit(msr, msr_bitmap + 0xc00 / f);

        }
}

static void __vmx_enable_intercept_for_msr(unsigned long *msr_bitmap,
                                                u32 msr, int type)
{
        int f = sizeof(unsigned long);

        if (!cpu_has_vmx_msr_bitmap())
                return;

        /*
         * See Intel PRM Vol. 3, 20.6.9 (MSR-Bitmap Address). Early manuals
         * have the write-low and read-high bitmap offsets the wrong way round.
         * We can control MSRs 0x00000000-0x00001fff and 0xc0000000-0xc0001fff.
         */
        if (msr <= 0x1fff) {
                if (type & MSR_TYPE_R)
                        /* read-low */
                        __set_bit(msr, msr_bitmap + 0x000 / f);

                if (type & MSR_TYPE_W)
                        /* write-low */
                        __set_bit(msr, msr_bitmap + 0x800 / f);

        } else if ((msr >= 0xc0000000) && (msr <= 0xc0001fff)) {
                msr &= 0x1fff;
                if (type & MSR_TYPE_R)
                        /* read-high */
                        __set_bit(msr, msr_bitmap + 0x400 / f);

                if (type & MSR_TYPE_W)
                        /* write-high */
                        __set_bit(msr, msr_bitmap + 0xc00 / f);

        }
}

static void vmx_disable_intercept_for_msr(u32 msr, bool longmode_only)
{
        if (!longmode_only)
                __vmx_disable_intercept_for_msr(vmx_msr_bitmap_legacy,
                                                msr, MSR_TYPE_R | MSR_TYPE_W);
        __vmx_disable_intercept_for_msr(vmx_msr_bitmap_longmode,
                                                msr, MSR_TYPE_R | MSR_TYPE_W);
}

static void vmx_enable_intercept_msr_read_x2apic(u32 msr)
{
        __vmx_enable_intercept_for_msr(vmx_msr_bitmap_legacy_x2apic,
                        msr, MSR_TYPE_R);
        __vmx_enable_intercept_for_msr(vmx_msr_bitmap_longmode_x2apic,
                        msr, MSR_TYPE_R);
}

static void vmx_disable_intercept_msr_read_x2apic(u32 msr)
{
        __vmx_disable_intercept_for_msr(vmx_msr_bitmap_legacy_x2apic,
                        msr, MSR_TYPE_R);
        __vmx_disable_intercept_for_msr(vmx_msr_bitmap_longmode_x2apic,
                        msr, MSR_TYPE_R);
}

static void vmx_disable_intercept_msr_write_x2apic(u32 msr)
{
        __vmx_disable_intercept_for_msr(vmx_msr_bitmap_legacy_x2apic,
                        msr, MSR_TYPE_W);
        __vmx_disable_intercept_for_msr(vmx_msr_bitmap_longmode_x2apic,
                        msr, MSR_TYPE_W);
}

static int vmx_vm_has_apicv(struct kvm *kvm)
{
        return enable_apicv && irqchip_in_kernel(kvm);
}

/*
 * Send interrupt to vcpu via posted interrupt way.
 * 1. If target vcpu is running(non-root mode), send posted interrupt
 * notification to vcpu and hardware will sync PIR to vIRR atomically.
 * 2. If target vcpu isn't running(root mode), kick it to pick up the
 * interrupt from PIR in next vmentry.
 */
static void vmx_deliver_posted_interrupt(struct kvm_vcpu *vcpu, int vector)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);
        int r;

        if (pi_test_and_set_pir(vector, &vmx->pi_desc))
                return;

        r = pi_test_and_set_on(&vmx->pi_desc);
        kvm_make_request(KVM_REQ_EVENT, vcpu);
#ifdef CONFIG_SMP
        if (!r && (vcpu->mode == IN_GUEST_MODE))
                apic->send_IPI_mask(get_cpu_mask(vcpu->cpu),
                                POSTED_INTR_VECTOR);
        else
#endif
                kvm_vcpu_kick(vcpu);
}

static void vmx_sync_pir_to_irr(struct kvm_vcpu *vcpu)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);

        if (!pi_test_and_clear_on(&vmx->pi_desc))
                return;

        kvm_apic_update_irr(vcpu, vmx->pi_desc.pir);
}

static void vmx_sync_pir_to_irr_dummy(struct kvm_vcpu *vcpu)
{
        return;
}

/*
 * Set up the vmcs's constant host-state fields, i.e., host-state fields that
 * will not change in the lifetime of the guest.
 * Note that host-state that does change is set elsewhere. E.g., host-state
 * that is set differently for each CPU is set in vmx_vcpu_load(), not here.
 */
static void vmx_set_constant_host_state(struct vcpu_vmx *vmx)
{
        u32 low32, high32;
        unsigned long tmpl;
        struct desc_ptr dt;
        unsigned long cr4;

        vmcs_writel(HOST_CR0, read_cr0() & ~X86_CR0_TS);  /* 22.2.3 */
        vmcs_writel(HOST_CR3, read_cr3());  /* 22.2.3  FIXME: shadow tables */

        /* Save the most likely value for this task's CR4 in the VMCS. */
        cr4 = read_cr4();
        vmcs_writel(HOST_CR4, cr4);                     /* 22.2.3, 22.2.5 */
        vmx->host_state.vmcs_host_cr4 = cr4;

        vmcs_write16(HOST_CS_SELECTOR, __KERNEL_CS);  /* 22.2.4 */
#ifdef CONFIG_X86_64
        /*
         * Load null selectors, so we can avoid reloading them in
         * __vmx_load_host_state(), in case userspace uses the null selectors
         * too (the expected case).
         */
        vmcs_write16(HOST_DS_SELECTOR, 0);
        vmcs_write16(HOST_ES_SELECTOR, 0);
#else
        vmcs_write16(HOST_DS_SELECTOR, __KERNEL_DS);  /* 22.2.4 */
        vmcs_write16(HOST_ES_SELECTOR, __KERNEL_DS);  /* 22.2.4 */
#endif
        vmcs_write16(HOST_SS_SELECTOR, __KERNEL_DS);  /* 22.2.4 */
        vmcs_write16(HOST_TR_SELECTOR, GDT_ENTRY_TSS*8);  /* 22.2.4 */

        native_store_idt(&dt);
        vmcs_writel(HOST_IDTR_BASE, dt.address);   /* 22.2.4 */
        vmx->host_idt_base = dt.address;

        vmcs_writel(HOST_RIP, vmx_return); /* 22.2.5 */

        rdmsr(MSR_IA32_SYSENTER_CS, low32, high32);
        vmcs_write32(HOST_IA32_SYSENTER_CS, low32);
        rdmsrl(MSR_IA32_SYSENTER_EIP, tmpl);
        vmcs_writel(HOST_IA32_SYSENTER_EIP, tmpl);   /* 22.2.3 */

        if (vmcs_config.vmexit_ctrl & VM_EXIT_LOAD_IA32_PAT) {
                rdmsr(MSR_IA32_CR_PAT, low32, high32);
                vmcs_write64(HOST_IA32_PAT, low32 | ((u64) high32 << 32));
        }
}

static void set_cr4_guest_host_mask(struct vcpu_vmx *vmx)
{
        vmx->vcpu.arch.cr4_guest_owned_bits = KVM_CR4_GUEST_OWNED_BITS;
        if (enable_ept)
                vmx->vcpu.arch.cr4_guest_owned_bits |= X86_CR4_PGE;
        if (is_guest_mode(&vmx->vcpu))
                vmx->vcpu.arch.cr4_guest_owned_bits &=
                        ~get_vmcs12(&vmx->vcpu)->cr4_guest_host_mask;
        vmcs_writel(CR4_GUEST_HOST_MASK, ~vmx->vcpu.arch.cr4_guest_owned_bits);
}

static u32 vmx_pin_based_exec_ctrl(struct vcpu_vmx *vmx)
{
        u32 pin_based_exec_ctrl = vmcs_config.pin_based_exec_ctrl;

        if (!vmx_vm_has_apicv(vmx->vcpu.kvm))
                pin_based_exec_ctrl &= ~PIN_BASED_POSTED_INTR;
        return pin_based_exec_ctrl;
}

static u32 vmx_exec_control(struct vcpu_vmx *vmx)
{
        u32 exec_control = vmcs_config.cpu_based_exec_ctrl;

        if (vmx->vcpu.arch.switch_db_regs & KVM_DEBUGREG_WONT_EXIT)
                exec_control &= ~CPU_BASED_MOV_DR_EXITING;

        if (!vm_need_tpr_shadow(vmx->vcpu.kvm)) {
                exec_control &= ~CPU_BASED_TPR_SHADOW;
#ifdef CONFIG_X86_64
                exec_control |= CPU_BASED_CR8_STORE_EXITING |
                                CPU_BASED_CR8_LOAD_EXITING;
#endif
        }
        if (!enable_ept)
                exec_control |= CPU_BASED_CR3_STORE_EXITING |
                                CPU_BASED_CR3_LOAD_EXITING  |
                                CPU_BASED_INVLPG_EXITING;
        return exec_control;
}

static u32 vmx_secondary_exec_control(struct vcpu_vmx *vmx)
{
        u32 exec_control = vmcs_config.cpu_based_2nd_exec_ctrl;
        if (!vm_need_virtualize_apic_accesses(vmx->vcpu.kvm))
                exec_control &= ~SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES;
        if (vmx->vpid == 0)
                exec_control &= ~SECONDARY_EXEC_ENABLE_VPID;
        if (!enable_ept) {
                exec_control &= ~SECONDARY_EXEC_ENABLE_EPT;
                enable_unrestricted_guest = 0;
                /* Enable INVPCID for non-ept guests may cause performance regression. */
                exec_control &= ~SECONDARY_EXEC_ENABLE_INVPCID;
        }
        if (!enable_unrestricted_guest)
                exec_control &= ~SECONDARY_EXEC_UNRESTRICTED_GUEST;
        if (!ple_gap)
                exec_control &= ~SECONDARY_EXEC_PAUSE_LOOP_EXITING;
        if (!vmx_vm_has_apicv(vmx->vcpu.kvm))
                exec_control &= ~(SECONDARY_EXEC_APIC_REGISTER_VIRT |
                                  SECONDARY_EXEC_VIRTUAL_INTR_DELIVERY);
        exec_control &= ~SECONDARY_EXEC_VIRTUALIZE_X2APIC_MODE;
        /* SECONDARY_EXEC_SHADOW_VMCS is enabled when L1 executes VMPTRLD
           (handle_vmptrld).
           We can NOT enable shadow_vmcs here because we don't have yet
           a current VMCS12
        */
        exec_control &= ~SECONDARY_EXEC_SHADOW_VMCS;
        return exec_control;
}

static void ept_set_mmio_spte_mask(void)
{
        /*
         * EPT Misconfigurations can be generated if the value of bits 2:0
         * of an EPT paging-structure entry is 110b (write/execute).
         * Also, magic bits (0x3ull << 62) is set to quickly identify mmio
         * spte.
         */
        kvm_mmu_set_mmio_spte_mask((0x3ull << 62) | 0x6ull);
}

/*
 * Sets up the vmcs for emulated real mode.
 */
static int vmx_vcpu_setup(struct vcpu_vmx *vmx)
{
#ifdef CONFIG_X86_64
        unsigned long a;
#endif
        int i;

        /* I/O */
        vmcs_write64(IO_BITMAP_A, __pa(vmx_io_bitmap_a));
        vmcs_write64(IO_BITMAP_B, __pa(vmx_io_bitmap_b));

        if (enable_shadow_vmcs) {
                vmcs_write64(VMREAD_BITMAP, __pa(vmx_vmread_bitmap));
                vmcs_write64(VMWRITE_BITMAP, __pa(vmx_vmwrite_bitmap));
        }
        if (cpu_has_vmx_msr_bitmap())
                vmcs_write64(MSR_BITMAP, __pa(vmx_msr_bitmap_legacy));

        vmcs_write64(VMCS_LINK_POINTER, -1ull); /* 22.3.1.5 */

        /* Control */
        vmcs_write32(PIN_BASED_VM_EXEC_CONTROL, vmx_pin_based_exec_ctrl(vmx));

        vmcs_write32(CPU_BASED_VM_EXEC_CONTROL, vmx_exec_control(vmx));

        if (cpu_has_secondary_exec_ctrls()) {
                vmcs_write32(SECONDARY_VM_EXEC_CONTROL,
                                vmx_secondary_exec_control(vmx));
        }

        if (vmx_vm_has_apicv(vmx->vcpu.kvm)) {
                vmcs_write64(EOI_EXIT_BITMAP0, 0);
                vmcs_write64(EOI_EXIT_BITMAP1, 0);
                vmcs_write64(EOI_EXIT_BITMAP2, 0);
                vmcs_write64(EOI_EXIT_BITMAP3, 0);

                vmcs_write16(GUEST_INTR_STATUS, 0);

                vmcs_write64(POSTED_INTR_NV, POSTED_INTR_VECTOR);
                vmcs_write64(POSTED_INTR_DESC_ADDR, __pa((&vmx->pi_desc)));
        }

        if (ple_gap) {
                vmcs_write32(PLE_GAP, ple_gap);
                vmx->ple_window = ple_window;
                vmx->ple_window_dirty = true;
        }

        vmcs_write32(PAGE_FAULT_ERROR_CODE_MASK, 0);
        vmcs_write32(PAGE_FAULT_ERROR_CODE_MATCH, 0);
        vmcs_write32(CR3_TARGET_COUNT, 0);           /* 22.2.1 */

        vmcs_write16(HOST_FS_SELECTOR, 0);            /* 22.2.4 */
        vmcs_write16(HOST_GS_SELECTOR, 0);            /* 22.2.4 */
        vmx_set_constant_host_state(vmx);
#ifdef CONFIG_X86_64
        rdmsrl(MSR_FS_BASE, a);
        vmcs_writel(HOST_FS_BASE, a); /* 22.2.4 */
        rdmsrl(MSR_GS_BASE, a);
        vmcs_writel(HOST_GS_BASE, a); /* 22.2.4 */
#else
        vmcs_writel(HOST_FS_BASE, 0); /* 22.2.4 */
        vmcs_writel(HOST_GS_BASE, 0); /* 22.2.4 */
#endif

        vmcs_write32(VM_EXIT_MSR_STORE_COUNT, 0);
        vmcs_write32(VM_EXIT_MSR_LOAD_COUNT, 0);
        vmcs_write64(VM_EXIT_MSR_LOAD_ADDR, __pa(vmx->msr_autoload.host));
        vmcs_write32(VM_ENTRY_MSR_LOAD_COUNT, 0);
        vmcs_write64(VM_ENTRY_MSR_LOAD_ADDR, __pa(vmx->msr_autoload.guest));

        if (vmcs_config.vmentry_ctrl & VM_ENTRY_LOAD_IA32_PAT) {
                u32 msr_low, msr_high;
                u64 host_pat;
                rdmsr(MSR_IA32_CR_PAT, msr_low, msr_high);
                host_pat = msr_low | ((u64) msr_high << 32);
                /* Write the default value follow host pat */
                vmcs_write64(GUEST_IA32_PAT, host_pat);
                /* Keep arch.pat sync with GUEST_IA32_PAT */
                vmx->vcpu.arch.pat = host_pat;
        }

        for (i = 0; i < ARRAY_SIZE(vmx_msr_index); ++i) {
                u32 index = vmx_msr_index[i];
                u32 data_low, data_high;
                int j = vmx->nmsrs;

                if (rdmsr_safe(index, &data_low, &data_high) < 0)
                        continue;
                if (wrmsr_safe(index, data_low, data_high) < 0)
                        continue;
                vmx->guest_msrs[j].index = i;
                vmx->guest_msrs[j].data = 0;
                vmx->guest_msrs[j].mask = -1ull;
                ++vmx->nmsrs;
        }


        vm_exit_controls_init(vmx, vmcs_config.vmexit_ctrl);

        /* 22.2.1, 20.8.1 */
        vm_entry_controls_init(vmx, vmcs_config.vmentry_ctrl);

        vmcs_writel(CR0_GUEST_HOST_MASK, ~0UL);
        set_cr4_guest_host_mask(vmx);

        return 0;
}

static void vmx_vcpu_reset(struct kvm_vcpu *vcpu)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);
        struct msr_data apic_base_msr;

        vmx->rmode.vm86_active = 0;

        vmx->soft_vnmi_blocked = 0;

        vmx->vcpu.arch.regs[VCPU_REGS_RDX] = get_rdx_init_val();
        kvm_set_cr8(&vmx->vcpu, 0);
        apic_base_msr.data = APIC_DEFAULT_PHYS_BASE | MSR_IA32_APICBASE_ENABLE;
        if (kvm_vcpu_is_bsp(&vmx->vcpu))
                apic_base_msr.data |= MSR_IA32_APICBASE_BSP;
        apic_base_msr.host_initiated = true;
        kvm_set_apic_base(&vmx->vcpu, &apic_base_msr);

        vmx_segment_cache_clear(vmx);

        seg_setup(VCPU_SREG_CS);
        vmcs_write16(GUEST_CS_SELECTOR, 0xf000);
        vmcs_write32(GUEST_CS_BASE, 0xffff0000);

        seg_setup(VCPU_SREG_DS);
        seg_setup(VCPU_SREG_ES);
        seg_setup(VCPU_SREG_FS);
        seg_setup(VCPU_SREG_GS);
        seg_setup(VCPU_SREG_SS);

        vmcs_write16(GUEST_TR_SELECTOR, 0);
        vmcs_writel(GUEST_TR_BASE, 0);
        vmcs_write32(GUEST_TR_LIMIT, 0xffff);
        vmcs_write32(GUEST_TR_AR_BYTES, 0x008b);

        vmcs_write16(GUEST_LDTR_SELECTOR, 0);
        vmcs_writel(GUEST_LDTR_BASE, 0);
        vmcs_write32(GUEST_LDTR_LIMIT, 0xffff);
        vmcs_write32(GUEST_LDTR_AR_BYTES, 0x00082);

        vmcs_write32(GUEST_SYSENTER_CS, 0);
        vmcs_writel(GUEST_SYSENTER_ESP, 0);
        vmcs_writel(GUEST_SYSENTER_EIP, 0);

        vmcs_writel(GUEST_RFLAGS, 0x02);
        kvm_rip_write(vcpu, 0xfff0);

        vmcs_writel(GUEST_GDTR_BASE, 0);
        vmcs_write32(GUEST_GDTR_LIMIT, 0xffff);

        vmcs_writel(GUEST_IDTR_BASE, 0);
        vmcs_write32(GUEST_IDTR_LIMIT, 0xffff);

        vmcs_write32(GUEST_ACTIVITY_STATE, GUEST_ACTIVITY_ACTIVE);
        vmcs_write32(GUEST_INTERRUPTIBILITY_INFO, 0);
        vmcs_write32(GUEST_PENDING_DBG_EXCEPTIONS, 0);

        /* Special registers */
        vmcs_write64(GUEST_IA32_DEBUGCTL, 0);

        setup_msrs(vmx);

        vmcs_write32(VM_ENTRY_INTR_INFO_FIELD, 0);  /* 22.2.1 */

        if (cpu_has_vmx_tpr_shadow()) {
                vmcs_write64(VIRTUAL_APIC_PAGE_ADDR, 0);
                if (vm_need_tpr_shadow(vmx->vcpu.kvm))
                        vmcs_write64(VIRTUAL_APIC_PAGE_ADDR,
                                     __pa(vmx->vcpu.arch.apic->regs));
                vmcs_write32(TPR_THRESHOLD, 0);
        }

        kvm_vcpu_reload_apic_access_page(vcpu);

        if (vmx_vm_has_apicv(vcpu->kvm))
                memset(&vmx->pi_desc, 0, sizeof(struct pi_desc));

        if (vmx->vpid != 0)
                vmcs_write16(VIRTUAL_PROCESSOR_ID, vmx->vpid);

        vmx->vcpu.arch.cr0 = X86_CR0_NW | X86_CR0_CD | X86_CR0_ET;
        vmx_set_cr0(&vmx->vcpu, kvm_read_cr0(vcpu)); /* enter rmode */
        vmx_set_cr4(&vmx->vcpu, 0);
        vmx_set_efer(&vmx->vcpu, 0);
        vmx_fpu_activate(&vmx->vcpu);
        update_exception_bitmap(&vmx->vcpu);

        vpid_sync_context(vmx);
}

/*
 * In nested virtualization, check if L1 asked to exit on external interrupts.
 * For most existing hypervisors, this will always return true.
 */
static bool nested_exit_on_intr(struct kvm_vcpu *vcpu)
{
        return get_vmcs12(vcpu)->pin_based_vm_exec_control &
                PIN_BASED_EXT_INTR_MASK;
}

/*
 * In nested virtualization, check if L1 has set
 * VM_EXIT_ACK_INTR_ON_EXIT
 */
static bool nested_exit_intr_ack_set(struct kvm_vcpu *vcpu)
{
        return get_vmcs12(vcpu)->vm_exit_controls &
                VM_EXIT_ACK_INTR_ON_EXIT;
}

static bool nested_exit_on_nmi(struct kvm_vcpu *vcpu)
{
        return get_vmcs12(vcpu)->pin_based_vm_exec_control &
                PIN_BASED_NMI_EXITING;
}

static void enable_irq_window(struct kvm_vcpu *vcpu)
{
        u32 cpu_based_vm_exec_control;

        cpu_based_vm_exec_control = vmcs_read32(CPU_BASED_VM_EXEC_CONTROL);
        cpu_based_vm_exec_control |= CPU_BASED_VIRTUAL_INTR_PENDING;
        vmcs_write32(CPU_BASED_VM_EXEC_CONTROL, cpu_based_vm_exec_control);
}

static void enable_nmi_window(struct kvm_vcpu *vcpu)
{
        u32 cpu_based_vm_exec_control;

        if (!cpu_has_virtual_nmis() ||
            vmcs_read32(GUEST_INTERRUPTIBILITY_INFO) & GUEST_INTR_STATE_STI) {
                enable_irq_window(vcpu);
                return;
        }

        cpu_based_vm_exec_control = vmcs_read32(CPU_BASED_VM_EXEC_CONTROL);
        cpu_based_vm_exec_control |= CPU_BASED_VIRTUAL_NMI_PENDING;
        vmcs_write32(CPU_BASED_VM_EXEC_CONTROL, cpu_based_vm_exec_control);
}

static void vmx_inject_irq(struct kvm_vcpu *vcpu)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);
        uint32_t intr;
        int irq = vcpu->arch.interrupt.nr;

        trace_kvm_inj_virq(irq);

        ++vcpu->stat.irq_injections;
        if (vmx->rmode.vm86_active) {
                int inc_eip = 0;
                if (vcpu->arch.interrupt.soft)
                        inc_eip = vcpu->arch.event_exit_inst_len;
                if (kvm_inject_realmode_interrupt(vcpu, irq, inc_eip) != EMULATE_DONE)
                        kvm_make_request(KVM_REQ_TRIPLE_FAULT, vcpu);
                return;
        }
        intr = irq | INTR_INFO_VALID_MASK;
        if (vcpu->arch.interrupt.soft) {
                intr |= INTR_TYPE_SOFT_INTR;
                vmcs_write32(VM_ENTRY_INSTRUCTION_LEN,
                             vmx->vcpu.arch.event_exit_inst_len);
        } else
                intr |= INTR_TYPE_EXT_INTR;
        vmcs_write32(VM_ENTRY_INTR_INFO_FIELD, intr);
}

static void vmx_inject_nmi(struct kvm_vcpu *vcpu)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);

        if (is_guest_mode(vcpu))
                return;

        if (!cpu_has_virtual_nmis()) {
                /*
                 * Tracking the NMI-blocked state in software is built upon
                 * finding the next open IRQ window. This, in turn, depends on
                 * well-behaving guests: They have to keep IRQs disabled at
                 * least as long as the NMI handler runs. Otherwise we may
                 * cause NMI nesting, maybe breaking the guest. But as this is
                 * highly unlikely, we can live with the residual risk.
                 */
                vmx->soft_vnmi_blocked = 1;
                vmx->vnmi_blocked_time = 0;
        }

        ++vcpu->stat.nmi_injections;
        vmx->nmi_known_unmasked = false;
        if (vmx->rmode.vm86_active) {
                if (kvm_inject_realmode_interrupt(vcpu, NMI_VECTOR, 0) != EMULATE_DONE)
                        kvm_make_request(KVM_REQ_TRIPLE_FAULT, vcpu);
                return;
        }
        vmcs_write32(VM_ENTRY_INTR_INFO_FIELD,
                        INTR_TYPE_NMI_INTR | INTR_INFO_VALID_MASK | NMI_VECTOR);
}

static bool vmx_get_nmi_mask(struct kvm_vcpu *vcpu)
{
        if (!cpu_has_virtual_nmis())
                return to_vmx(vcpu)->soft_vnmi_blocked;
        if (to_vmx(vcpu)->nmi_known_unmasked)
                return false;
        return vmcs_read32(GUEST_INTERRUPTIBILITY_INFO) & GUEST_INTR_STATE_NMI;
}

static void vmx_set_nmi_mask(struct kvm_vcpu *vcpu, bool masked)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);

        if (!cpu_has_virtual_nmis()) {
                if (vmx->soft_vnmi_blocked != masked) {
                        vmx->soft_vnmi_blocked = masked;
                        vmx->vnmi_blocked_time = 0;
                }
        } else {
                vmx->nmi_known_unmasked = !masked;
                if (masked)
                        vmcs_set_bits(GUEST_INTERRUPTIBILITY_INFO,
                                      GUEST_INTR_STATE_NMI);
                else
                        vmcs_clear_bits(GUEST_INTERRUPTIBILITY_INFO,
                                        GUEST_INTR_STATE_NMI);
        }
}

static int vmx_nmi_allowed(struct kvm_vcpu *vcpu)
{
        if (to_vmx(vcpu)->nested.nested_run_pending)
                return 0;

        if (!cpu_has_virtual_nmis() && to_vmx(vcpu)->soft_vnmi_blocked)
                return 0;

        return  !(vmcs_read32(GUEST_INTERRUPTIBILITY_INFO) &
                  (GUEST_INTR_STATE_MOV_SS | GUEST_INTR_STATE_STI
                   | GUEST_INTR_STATE_NMI));
}

static int vmx_interrupt_allowed(struct kvm_vcpu *vcpu)
{
        return (!to_vmx(vcpu)->nested.nested_run_pending &&
                vmcs_readl(GUEST_RFLAGS) & X86_EFLAGS_IF) &&
                !(vmcs_read32(GUEST_INTERRUPTIBILITY_INFO) &
                        (GUEST_INTR_STATE_STI | GUEST_INTR_STATE_MOV_SS));
}

static int vmx_set_tss_addr(struct kvm *kvm, unsigned int addr)
{
        int ret;
        struct kvm_userspace_memory_region tss_mem = {
                .slot = TSS_PRIVATE_MEMSLOT,
                .guest_phys_addr = addr,
                .memory_size = PAGE_SIZE * 3,
                .flags = 0,
        };

        ret = kvm_set_memory_region(kvm, &tss_mem);
        if (ret)
                return ret;
        kvm->arch.tss_addr = addr;
        return init_rmode_tss(kvm);
}

static bool rmode_exception(struct kvm_vcpu *vcpu, int vec)
{
        switch (vec) {
        case BP_VECTOR:
                /*
                 * Update instruction length as we may reinject the exception
                 * from user space while in guest debugging mode.
                 */
                to_vmx(vcpu)->vcpu.arch.event_exit_inst_len =
                        vmcs_read32(VM_EXIT_INSTRUCTION_LEN);
                if (vcpu->guest_debug & KVM_GUESTDBG_USE_SW_BP)
                        return false;
                /* fall through */
        case DB_VECTOR:
                if (vcpu->guest_debug &
                        (KVM_GUESTDBG_SINGLESTEP | KVM_GUESTDBG_USE_HW_BP))
                        return false;
                /* fall through */
        case DE_VECTOR:
        case OF_VECTOR:
        case BR_VECTOR:
        case UD_VECTOR:
        case DF_VECTOR:
        case SS_VECTOR:
        case GP_VECTOR:
        case MF_VECTOR:
                return true;
        break;
        }
        return false;
}

static int handle_rmode_exception(struct kvm_vcpu *vcpu,
                                  int vec, u32 err_code)
{
        /*
         * Instruction with address size override prefix opcode 0x67
         * Cause the #SS fault with 0 error code in VM86 mode.
         */
        if (((vec == GP_VECTOR) || (vec == SS_VECTOR)) && err_code == 0) {
                if (emulate_instruction(vcpu, 0) == EMULATE_DONE) {
                        if (vcpu->arch.halt_request) {
                                vcpu->arch.halt_request = 0;
                                return kvm_emulate_halt(vcpu);
                        }
                        return 1;
                }
                return 0;
        }

        /*
         * Forward all other exceptions that are valid in real mode.
         * FIXME: Breaks guest debugging in real mode, needs to be fixed with
         *        the required debugging infrastructure rework.
         */
        kvm_queue_exception(vcpu, vec);
        return 1;
}

/*
 * Trigger machine check on the host. We assume all the MSRs are already set up
 * by the CPU and that we still run on the same CPU as the MCE occurred on.
 * We pass a fake environment to the machine check handler because we want
 * the guest to be always treated like user space, no matter what context
 * it used internally.
 */
static void kvm_machine_check(void)
{
#if defined(CONFIG_X86_MCE) && defined(CONFIG_X86_64)
        struct pt_regs regs = {
                .cs = 3, /* Fake ring 3 no matter what the guest ran on */
                .flags = X86_EFLAGS_IF,
        };

        do_machine_check(&regs, 0);
#endif
}

static int handle_machine_check(struct kvm_vcpu *vcpu)
{
        /* already handled by vcpu_run */
        return 1;
}

static int handle_exception(struct kvm_vcpu *vcpu)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);
        struct kvm_run *kvm_run = vcpu->run;
        u32 intr_info, ex_no, error_code;
        unsigned long cr2, rip, dr6;
        u32 vect_info;
        enum emulation_result er;

        vect_info = vmx->idt_vectoring_info;
        intr_info = vmx->exit_intr_info;

        if (is_machine_check(intr_info))
                return handle_machine_check(vcpu);

        if ((intr_info & INTR_INFO_INTR_TYPE_MASK) == INTR_TYPE_NMI_INTR)
                return 1;  /* already handled by vmx_vcpu_run() */

        if (is_no_device(intr_info)) {
                vmx_fpu_activate(vcpu);
                return 1;
        }

        if (is_invalid_opcode(intr_info)) {
                er = emulate_instruction(vcpu, EMULTYPE_TRAP_UD);
                if (er != EMULATE_DONE)
                        kvm_queue_exception(vcpu, UD_VECTOR);
                return 1;
        }

        error_code = 0;
        if (intr_info & INTR_INFO_DELIVER_CODE_MASK)
                error_code = vmcs_read32(VM_EXIT_INTR_ERROR_CODE);

        /*
         * The #PF with PFEC.RSVD = 1 indicates the guest is accessing
         * MMIO, it is better to report an internal error.
         * See the comments in vmx_handle_exit.
         */
        if ((vect_info & VECTORING_INFO_VALID_MASK) &&
            !(is_page_fault(intr_info) && !(error_code & PFERR_RSVD_MASK))) {
                vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
                vcpu->run->internal.suberror = KVM_INTERNAL_ERROR_SIMUL_EX;
                vcpu->run->internal.ndata = 2;
                vcpu->run->internal.data[0] = vect_info;
                vcpu->run->internal.data[1] = intr_info;
                return 0;
        }

        if (is_page_fault(intr_info)) {
                /* EPT won't cause page fault directly */
                BUG_ON(enable_ept);
                cr2 = vmcs_readl(EXIT_QUALIFICATION);
                trace_kvm_page_fault(cr2, error_code);

                if (kvm_event_needs_reinjection(vcpu))
                        kvm_mmu_unprotect_page_virt(vcpu, cr2);
                return kvm_mmu_page_fault(vcpu, cr2, error_code, NULL, 0);
        }

        ex_no = intr_info & INTR_INFO_VECTOR_MASK;

        if (vmx->rmode.vm86_active && rmode_exception(vcpu, ex_no))
                return handle_rmode_exception(vcpu, ex_no, error_code);

        switch (ex_no) {
        case DB_VECTOR:
                dr6 = vmcs_readl(EXIT_QUALIFICATION);
                if (!(vcpu->guest_debug &
                      (KVM_GUESTDBG_SINGLESTEP | KVM_GUESTDBG_USE_HW_BP))) {
                        vcpu->arch.dr6 &= ~15;
                        vcpu->arch.dr6 |= dr6 | DR6_RTM;
                        if (!(dr6 & ~DR6_RESERVED)) /* icebp */
                                skip_emulated_instruction(vcpu);

                        kvm_queue_exception(vcpu, DB_VECTOR);
                        return 1;
                }
                kvm_run->debug.arch.dr6 = dr6 | DR6_FIXED_1;
                kvm_run->debug.arch.dr7 = vmcs_readl(GUEST_DR7);
                /* fall through */
        case BP_VECTOR:
                /*
                 * Update instruction length as we may reinject #BP from
                 * user space while in guest debugging mode. Reading it for
                 * #DB as well causes no harm, it is not used in that case.
                 */
                vmx->vcpu.arch.event_exit_inst_len =
                        vmcs_read32(VM_EXIT_INSTRUCTION_LEN);
                kvm_run->exit_reason = KVM_EXIT_DEBUG;
                rip = kvm_rip_read(vcpu);
                kvm_run->debug.arch.pc = vmcs_readl(GUEST_CS_BASE) + rip;
                kvm_run->debug.arch.exception = ex_no;
                break;
        default:
                kvm_run->exit_reason = KVM_EXIT_EXCEPTION;
                kvm_run->ex.exception = ex_no;
                kvm_run->ex.error_code = error_code;
                break;
        }
        return 0;
}

static int handle_external_interrupt(struct kvm_vcpu *vcpu)
{
        ++vcpu->stat.irq_exits;
        return 1;
}

static int handle_triple_fault(struct kvm_vcpu *vcpu)
{
        vcpu->run->exit_reason = KVM_EXIT_SHUTDOWN;
        return 0;
}

static int handle_io(struct kvm_vcpu *vcpu)
{
        unsigned long exit_qualification;
        int size, in, string;
        unsigned port;

        exit_qualification = vmcs_readl(EXIT_QUALIFICATION);
        string = (exit_qualification & 16) != 0;
        in = (exit_qualification & 8) != 0;

        ++vcpu->stat.io_exits;

        if (string || in)
                return emulate_instruction(vcpu, 0) == EMULATE_DONE;

        port = exit_qualification >> 16;
        size = (exit_qualification & 7) + 1;
        skip_emulated_instruction(vcpu);

        return kvm_fast_pio_out(vcpu, size, port);
}

static void
vmx_patch_hypercall(struct kvm_vcpu *vcpu, unsigned char *hypercall)
{
        /*
         * Patch in the VMCALL instruction:
         */
        hypercall[0] = 0x0f;
        hypercall[1] = 0x01;
        hypercall[2] = 0xc1;
}

static bool nested_cr0_valid(struct vmcs12 *vmcs12, unsigned long val)
{
        unsigned long always_on = VMXON_CR0_ALWAYSON;

        if (nested_vmx_secondary_ctls_high &
                SECONDARY_EXEC_UNRESTRICTED_GUEST &&
            nested_cpu_has2(vmcs12, SECONDARY_EXEC_UNRESTRICTED_GUEST))
                always_on &= ~(X86_CR0_PE | X86_CR0_PG);
        return (val & always_on) == always_on;
}

/* called to set cr0 as appropriate for a mov-to-cr0 exit. */
static int handle_set_cr0(struct kvm_vcpu *vcpu, unsigned long val)
{
        if (is_guest_mode(vcpu)) {
                struct vmcs12 *vmcs12 = get_vmcs12(vcpu);
                unsigned long orig_val = val;

                /*
                 * We get here when L2 changed cr0 in a way that did not change
                 * any of L1's shadowed bits (see nested_vmx_exit_handled_cr),
                 * but did change L0 shadowed bits. So we first calculate the
                 * effective cr0 value that L1 would like to write into the
                 * hardware. It consists of the L2-owned bits from the new
                 * value combined with the L1-owned bits from L1's guest_cr0.
                 */
                val = (val & ~vmcs12->cr0_guest_host_mask) |
                        (vmcs12->guest_cr0 & vmcs12->cr0_guest_host_mask);

                if (!nested_cr0_valid(vmcs12, val))
                        return 1;

                if (kvm_set_cr0(vcpu, val))
                        return 1;
                vmcs_writel(CR0_READ_SHADOW, orig_val);
                return 0;
        } else {
                if (to_vmx(vcpu)->nested.vmxon &&
                    ((val & VMXON_CR0_ALWAYSON) != VMXON_CR0_ALWAYSON))
                        return 1;
                return kvm_set_cr0(vcpu, val);
        }
}

static int handle_set_cr4(struct kvm_vcpu *vcpu, unsigned long val)
{
        if (is_guest_mode(vcpu)) {
                struct vmcs12 *vmcs12 = get_vmcs12(vcpu);
                unsigned long orig_val = val;

                /* analogously to handle_set_cr0 */
                val = (val & ~vmcs12->cr4_guest_host_mask) |
                        (vmcs12->guest_cr4 & vmcs12->cr4_guest_host_mask);
                if (kvm_set_cr4(vcpu, val))
                        return 1;
                vmcs_writel(CR4_READ_SHADOW, orig_val);
                return 0;
        } else
                return kvm_set_cr4(vcpu, val);
}

/* called to set cr0 as approriate for clts instruction exit. */
static void handle_clts(struct kvm_vcpu *vcpu)
{
        if (is_guest_mode(vcpu)) {
                /*
                 * We get here when L2 did CLTS, and L1 didn't shadow CR0.TS
                 * but we did (!fpu_active). We need to keep GUEST_CR0.TS on,
                 * just pretend it's off (also in arch.cr0 for fpu_activate).
                 */
                vmcs_writel(CR0_READ_SHADOW,
                        vmcs_readl(CR0_READ_SHADOW) & ~X86_CR0_TS);
                vcpu->arch.cr0 &= ~X86_CR0_TS;
        } else
                vmx_set_cr0(vcpu, kvm_read_cr0_bits(vcpu, ~X86_CR0_TS));
}

static int handle_cr(struct kvm_vcpu *vcpu)
{
        unsigned long exit_qualification, val;
        int cr;
        int reg;
        int err;

        exit_qualification = vmcs_readl(EXIT_QUALIFICATION);
        cr = exit_qualification & 15;
        reg = (exit_qualification >> 8) & 15;
        switch ((exit_qualification >> 4) & 3) {
        case 0: /* mov to cr */
                val = kvm_register_readl(vcpu, reg);
                trace_kvm_cr_write(cr, val);
                switch (cr) {
                case 0:
                        err = handle_set_cr0(vcpu, val);
                        kvm_complete_insn_gp(vcpu, err);
                        return 1;
                case 3:
                        err = kvm_set_cr3(vcpu, val);
                        kvm_complete_insn_gp(vcpu, err);
                        return 1;
                case 4:
                        err = handle_set_cr4(vcpu, val);
                        kvm_complete_insn_gp(vcpu, err);
                        return 1;
                case 8: {
                                u8 cr8_prev = kvm_get_cr8(vcpu);
                                u8 cr8 = (u8)val;
                                err = kvm_set_cr8(vcpu, cr8);
                                kvm_complete_insn_gp(vcpu, err);
                                if (irqchip_in_kernel(vcpu->kvm))
                                        return 1;
                                if (cr8_prev <= cr8)
                                        return 1;
                                vcpu->run->exit_reason = KVM_EXIT_SET_TPR;
                                return 0;
                        }
                }
                break;
        case 2: /* clts */
                handle_clts(vcpu);
                trace_kvm_cr_write(0, kvm_read_cr0(vcpu));
                skip_emulated_instruction(vcpu);
                vmx_fpu_activate(vcpu);
                return 1;
        case 1: /*mov from cr*/
                switch (cr) {
                case 3:
                        val = kvm_read_cr3(vcpu);
                        kvm_register_write(vcpu, reg, val);
                        trace_kvm_cr_read(cr, val);
                        skip_emulated_instruction(vcpu);
                        return 1;
                case 8:
                        val = kvm_get_cr8(vcpu);
                        kvm_register_write(vcpu, reg, val);
                        trace_kvm_cr_read(cr, val);
                        skip_emulated_instruction(vcpu);
                        return 1;
                }
                break;
        case 3: /* lmsw */
                val = (exit_qualification >> LMSW_SOURCE_DATA_SHIFT) & 0x0f;
                trace_kvm_cr_write(0, (kvm_read_cr0(vcpu) & ~0xful) | val);
                kvm_lmsw(vcpu, val);

                skip_emulated_instruction(vcpu);
                return 1;
        default:
                break;
        }
        vcpu->run->exit_reason = 0;
        vcpu_unimpl(vcpu, "unhandled control register: op %d cr %d\n",
               (int)(exit_qualification >> 4) & 3, cr);
        return 0;
}

static int handle_dr(struct kvm_vcpu *vcpu)
{
        unsigned long exit_qualification;
        int dr, reg;

        /* Do not handle if the CPL > 0, will trigger GP on re-entry */
        if (!kvm_require_cpl(vcpu, 0))
                return 1;
        dr = vmcs_readl(GUEST_DR7);
        if (dr & DR7_GD) {
                /*
                 * As the vm-exit takes precedence over the debug trap, we
                 * need to emulate the latter, either for the host or the
                 * guest debugging itself.
                 */
                if (vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP) {
                        vcpu->run->debug.arch.dr6 = vcpu->arch.dr6;
                        vcpu->run->debug.arch.dr7 = dr;
                        vcpu->run->debug.arch.pc =
                                vmcs_readl(GUEST_CS_BASE) +
                                vmcs_readl(GUEST_RIP);
                        vcpu->run->debug.arch.exception = DB_VECTOR;
                        vcpu->run->exit_reason = KVM_EXIT_DEBUG;
                        return 0;
                } else {
                        vcpu->arch.dr7 &= ~DR7_GD;
                        vcpu->arch.dr6 |= DR6_BD | DR6_RTM;
                        vmcs_writel(GUEST_DR7, vcpu->arch.dr7);
                        kvm_queue_exception(vcpu, DB_VECTOR);
                        return 1;
                }
        }

        if (vcpu->guest_debug == 0) {
                u32 cpu_based_vm_exec_control;

                cpu_based_vm_exec_control = vmcs_read32(CPU_BASED_VM_EXEC_CONTROL);
                cpu_based_vm_exec_control &= ~CPU_BASED_MOV_DR_EXITING;
                vmcs_write32(CPU_BASED_VM_EXEC_CONTROL, cpu_based_vm_exec_control);

                /*
                 * No more DR vmexits; force a reload of the debug registers
                 * and reenter on this instruction.  The next vmexit will
                 * retrieve the full state of the debug registers.
                 */
                vcpu->arch.switch_db_regs |= KVM_DEBUGREG_WONT_EXIT;
                return 1;
        }

        exit_qualification = vmcs_readl(EXIT_QUALIFICATION);
        dr = exit_qualification & DEBUG_REG_ACCESS_NUM;
        reg = DEBUG_REG_ACCESS_REG(exit_qualification);
        if (exit_qualification & TYPE_MOV_FROM_DR) {
                unsigned long val;

                if (kvm_get_dr(vcpu, dr, &val))
                        return 1;
                kvm_register_write(vcpu, reg, val);
        } else
                if (kvm_set_dr(vcpu, dr, kvm_register_readl(vcpu, reg)))
                        return 1;

        skip_emulated_instruction(vcpu);
        return 1;
}

static u64 vmx_get_dr6(struct kvm_vcpu *vcpu)
{
        return vcpu->arch.dr6;
}

static void vmx_set_dr6(struct kvm_vcpu *vcpu, unsigned long val)
{
}

static void vmx_sync_dirty_debug_regs(struct kvm_vcpu *vcpu)
{
        u32 cpu_based_vm_exec_control;

        get_debugreg(vcpu->arch.db[0], 0);
        get_debugreg(vcpu->arch.db[1], 1);
        get_debugreg(vcpu->arch.db[2], 2);
        get_debugreg(vcpu->arch.db[3], 3);
        get_debugreg(vcpu->arch.dr6, 6);
        vcpu->arch.dr7 = vmcs_readl(GUEST_DR7);

        vcpu->arch.switch_db_regs &= ~KVM_DEBUGREG_WONT_EXIT;

        cpu_based_vm_exec_control = vmcs_read32(CPU_BASED_VM_EXEC_CONTROL);
        cpu_based_vm_exec_control |= CPU_BASED_MOV_DR_EXITING;
        vmcs_write32(CPU_BASED_VM_EXEC_CONTROL, cpu_based_vm_exec_control);
}

static void vmx_set_dr7(struct kvm_vcpu *vcpu, unsigned long val)
{
        vmcs_writel(GUEST_DR7, val);
}

static int handle_cpuid(struct kvm_vcpu *vcpu)
{
        kvm_emulate_cpuid(vcpu);
        return 1;
}

static int handle_rdmsr(struct kvm_vcpu *vcpu)
{
        u32 ecx = vcpu->arch.regs[VCPU_REGS_RCX];
        u64 data;

        if (vmx_get_msr(vcpu, ecx, &data)) {
                trace_kvm_msr_read_ex(ecx);
                kvm_inject_gp(vcpu, 0);
                return 1;
        }

        trace_kvm_msr_read(ecx, data);

        /* FIXME: handling of bits 32:63 of rax, rdx */
        vcpu->arch.regs[VCPU_REGS_RAX] = data & -1u;
        vcpu->arch.regs[VCPU_REGS_RDX] = (data >> 32) & -1u;
        skip_emulated_instruction(vcpu);
        return 1;
}

static int handle_wrmsr(struct kvm_vcpu *vcpu)
{
        struct msr_data msr;
        u32 ecx = vcpu->arch.regs[VCPU_REGS_RCX];
        u64 data = (vcpu->arch.regs[VCPU_REGS_RAX] & -1u)
                | ((u64)(vcpu->arch.regs[VCPU_REGS_RDX] & -1u) << 32);

        msr.data = data;
        msr.index = ecx;
        msr.host_initiated = false;
        if (vmx_set_msr(vcpu, &msr) != 0) {
                trace_kvm_msr_write_ex(ecx, data);
                kvm_inject_gp(vcpu, 0);
                return 1;
        }

        trace_kvm_msr_write(ecx, data);
        skip_emulated_instruction(vcpu);
        return 1;
}

static int handle_tpr_below_threshold(struct kvm_vcpu *vcpu)
{
        kvm_make_request(KVM_REQ_EVENT, vcpu);
        return 1;
}

static int handle_interrupt_window(struct kvm_vcpu *vcpu)
{
        u32 cpu_based_vm_exec_control;

        /* clear pending irq */
        cpu_based_vm_exec_control = vmcs_read32(CPU_BASED_VM_EXEC_CONTROL);
        cpu_based_vm_exec_control &= ~CPU_BASED_VIRTUAL_INTR_PENDING;
        vmcs_write32(CPU_BASED_VM_EXEC_CONTROL, cpu_based_vm_exec_control);

        kvm_make_request(KVM_REQ_EVENT, vcpu);

        ++vcpu->stat.irq_window_exits;

        /*
         * If the user space waits to inject interrupts, exit as soon as
         * possible
         */
        if (!irqchip_in_kernel(vcpu->kvm) &&
            vcpu->run->request_interrupt_window &&
            !kvm_cpu_has_interrupt(vcpu)) {
                vcpu->run->exit_reason = KVM_EXIT_IRQ_WINDOW_OPEN;
                return 0;
        }
        return 1;
}

static int handle_halt(struct kvm_vcpu *vcpu)
{
        skip_emulated_instruction(vcpu);
        return kvm_emulate_halt(vcpu);
}

static int handle_vmcall(struct kvm_vcpu *vcpu)
{
        skip_emulated_instruction(vcpu);
        kvm_emulate_hypercall(vcpu);
        return 1;
}

static int handle_invd(struct kvm_vcpu *vcpu)
{
        return emulate_instruction(vcpu, 0) == EMULATE_DONE;
}

static int handle_invlpg(struct kvm_vcpu *vcpu)
{
        unsigned long exit_qualification = vmcs_readl(EXIT_QUALIFICATION);

        kvm_mmu_invlpg(vcpu, exit_qualification);
        skip_emulated_instruction(vcpu);
        return 1;
}

static int handle_rdpmc(struct kvm_vcpu *vcpu)
{
        int err;

        err = kvm_rdpmc(vcpu);
        kvm_complete_insn_gp(vcpu, err);

        return 1;
}

static int handle_wbinvd(struct kvm_vcpu *vcpu)
{
        skip_emulated_instruction(vcpu);
        kvm_emulate_wbinvd(vcpu);
        return 1;
}

static int handle_xsetbv(struct kvm_vcpu *vcpu)
{
        u64 new_bv = kvm_read_edx_eax(vcpu);
        u32 index = kvm_register_read(vcpu, VCPU_REGS_RCX);

        if (kvm_set_xcr(vcpu, index, new_bv) == 0)
                skip_emulated_instruction(vcpu);
        return 1;
}

static int handle_apic_access(struct kvm_vcpu *vcpu)
{
        if (likely(fasteoi)) {
                unsigned long exit_qualification = vmcs_readl(EXIT_QUALIFICATION);
                int access_type, offset;

                access_type = exit_qualification & APIC_ACCESS_TYPE;
                offset = exit_qualification & APIC_ACCESS_OFFSET;
                /*
                 * Sane guest uses MOV to write EOI, with written value
                 * not cared. So make a short-circuit here by avoiding
                 * heavy instruction emulation.
                 */
                if ((access_type == TYPE_LINEAR_APIC_INST_WRITE) &&
                    (offset == APIC_EOI)) {
                        kvm_lapic_set_eoi(vcpu);
                        skip_emulated_instruction(vcpu);
                        return 1;
                }
        }
        return emulate_instruction(vcpu, 0) == EMULATE_DONE;
}

static int handle_apic_eoi_induced(struct kvm_vcpu *vcpu)
{
        unsigned long exit_qualification = vmcs_readl(EXIT_QUALIFICATION);
        int vector = exit_qualification & 0xff;

        /* EOI-induced VM exit is trap-like and thus no need to adjust IP */
        kvm_apic_set_eoi_accelerated(vcpu, vector);
        return 1;
}

static int handle_apic_write(struct kvm_vcpu *vcpu)
{
        unsigned long exit_qualification = vmcs_readl(EXIT_QUALIFICATION);
        u32 offset = exit_qualification & 0xfff;

        /* APIC-write VM exit is trap-like and thus no need to adjust IP */
        kvm_apic_write_nodecode(vcpu, offset);
        return 1;
}

static int handle_task_switch(struct kvm_vcpu *vcpu)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);
        unsigned long exit_qualification;
        bool has_error_code = false;
        u32 error_code = 0;
        u16 tss_selector;
        int reason, type, idt_v, idt_index;

        idt_v = (vmx->idt_vectoring_info & VECTORING_INFO_VALID_MASK);
        idt_index = (vmx->idt_vectoring_info & VECTORING_INFO_VECTOR_MASK);
        type = (vmx->idt_vectoring_info & VECTORING_INFO_TYPE_MASK);

        exit_qualification = vmcs_readl(EXIT_QUALIFICATION);

        reason = (u32)exit_qualification >> 30;
        if (reason == TASK_SWITCH_GATE && idt_v) {
                switch (type) {
                case INTR_TYPE_NMI_INTR:
                        vcpu->arch.nmi_injected = false;
                        vmx_set_nmi_mask(vcpu, true);
                        break;
                case INTR_TYPE_EXT_INTR:
                case INTR_TYPE_SOFT_INTR:
                        kvm_clear_interrupt_queue(vcpu);
                        break;
                case INTR_TYPE_HARD_EXCEPTION:
                        if (vmx->idt_vectoring_info &
                            VECTORING_INFO_DELIVER_CODE_MASK) {
                                has_error_code = true;
                                error_code =
                                        vmcs_read32(IDT_VECTORING_ERROR_CODE);
                        }
                        /* fall through */
                case INTR_TYPE_SOFT_EXCEPTION:
                        kvm_clear_exception_queue(vcpu);
                        break;
                default:
                        break;
                }
        }
        tss_selector = exit_qualification;

        if (!idt_v || (type != INTR_TYPE_HARD_EXCEPTION &&
                       type != INTR_TYPE_EXT_INTR &&
                       type != INTR_TYPE_NMI_INTR))
                skip_emulated_instruction(vcpu);

        if (kvm_task_switch(vcpu, tss_selector,
                            type == INTR_TYPE_SOFT_INTR ? idt_index : -1, reason,
                            has_error_code, error_code) == EMULATE_FAIL) {
                vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
                vcpu->run->internal.suberror = KVM_INTERNAL_ERROR_EMULATION;
                vcpu->run->internal.ndata = 0;
                return 0;
        }

        /* clear all local breakpoint enable flags */
        vmcs_writel(GUEST_DR7, vmcs_readl(GUEST_DR7) & ~0x55);

        /*
         * TODO: What about debug traps on tss switch?
         *       Are we supposed to inject them and update dr6?
         */

        return 1;
}

static int handle_ept_violation(struct kvm_vcpu *vcpu)
{
        unsigned long exit_qualification;
        gpa_t gpa;
        u32 error_code;
        int gla_validity;

        exit_qualification = vmcs_readl(EXIT_QUALIFICATION);

        gla_validity = (exit_qualification >> 7) & 0x3;
        if (gla_validity != 0x3 && gla_validity != 0x1 && gla_validity != 0) {
                printk(KERN_ERR "EPT: Handling EPT violation failed!\n");
                printk(KERN_ERR "EPT: GPA: 0x%lx, GVA: 0x%lx\n",
                        (long unsigned int)vmcs_read64(GUEST_PHYSICAL_ADDRESS),
                        vmcs_readl(GUEST_LINEAR_ADDRESS));
                printk(KERN_ERR "EPT: Exit qualification is 0x%lx\n",
                        (long unsigned int)exit_qualification);
                vcpu->run->exit_reason = KVM_EXIT_UNKNOWN;
                vcpu->run->hw.hardware_exit_reason = EXIT_REASON_EPT_VIOLATION;
                return 0;
        }

        /*
         * EPT violation happened while executing iret from NMI,
         * "blocked by NMI" bit has to be set before next VM entry.
         * There are errata that may cause this bit to not be set:
         * AAK134, BY25.
         */
        if (!(to_vmx(vcpu)->idt_vectoring_info & VECTORING_INFO_VALID_MASK) &&
                        cpu_has_virtual_nmis() &&
                        (exit_qualification & INTR_INFO_UNBLOCK_NMI))
                vmcs_set_bits(GUEST_INTERRUPTIBILITY_INFO, GUEST_INTR_STATE_NMI);

        gpa = vmcs_read64(GUEST_PHYSICAL_ADDRESS);
        trace_kvm_page_fault(gpa, exit_qualification);

        /* It is a write fault? */
        error_code = exit_qualification & (1U << 1);
        /* It is a fetch fault? */
        error_code |= (exit_qualification & (1U << 2)) << 2;
        /* ept page table is present? */
        error_code |= (exit_qualification >> 3) & 0x1;

        vcpu->arch.exit_qualification = exit_qualification;

        return kvm_mmu_page_fault(vcpu, gpa, error_code, NULL, 0);
}

static u64 ept_rsvd_mask(u64 spte, int level)
{
        int i;
        u64 mask = 0;

        for (i = 51; i > boot_cpu_data.x86_phys_bits; i--)
                mask |= (1ULL << i);

        if (level == 4)
                /* bits 7:3 reserved */
                mask |= 0xf8;
        else if (spte & (1ULL << 7))
                /*
                 * 1GB/2MB page, bits 29:12 or 20:12 reserved respectively,
                 * level == 1 if the hypervisor is using the ignored bit 7.
                 */
                mask |= (PAGE_SIZE << ((level - 1) * 9)) - PAGE_SIZE;
        else if (level > 1)
                /* bits 6:3 reserved */
                mask |= 0x78;

        return mask;
}

static void ept_misconfig_inspect_spte(struct kvm_vcpu *vcpu, u64 spte,
                                       int level)
{
        printk(KERN_ERR "%s: spte 0x%llx level %d\n", __func__, spte, level);

        /* 010b (write-only) */
        WARN_ON((spte & 0x7) == 0x2);

        /* 110b (write/execute) */
        WARN_ON((spte & 0x7) == 0x6);

        /* 100b (execute-only) and value not supported by logical processor */
        if (!cpu_has_vmx_ept_execute_only())
                WARN_ON((spte & 0x7) == 0x4);

        /* not 000b */
        if ((spte & 0x7)) {
                u64 rsvd_bits = spte & ept_rsvd_mask(spte, level);

                if (rsvd_bits != 0) {
                        printk(KERN_ERR "%s: rsvd_bits = 0x%llx\n",
                                         __func__, rsvd_bits);
                        WARN_ON(1);
                }

                /* bits 5:3 are _not_ reserved for large page or leaf page */
                if ((rsvd_bits & 0x38) == 0) {
                        u64 ept_mem_type = (spte & 0x38) >> 3;

                        if (ept_mem_type == 2 || ept_mem_type == 3 ||
                            ept_mem_type == 7) {
                                printk(KERN_ERR "%s: ept_mem_type=0x%llx\n",
                                                __func__, ept_mem_type);
                                WARN_ON(1);
                        }
                }
        }
}

static int handle_ept_misconfig(struct kvm_vcpu *vcpu)
{
        u64 sptes[4];
        int nr_sptes, i, ret;
        gpa_t gpa;

        gpa = vmcs_read64(GUEST_PHYSICAL_ADDRESS);
        if (!kvm_io_bus_write(vcpu->kvm, KVM_FAST_MMIO_BUS, gpa, 0, NULL)) {
                skip_emulated_instruction(vcpu);
                return 1;
        }

        ret = handle_mmio_page_fault_common(vcpu, gpa, true);
        if (likely(ret == RET_MMIO_PF_EMULATE))
                return x86_emulate_instruction(vcpu, gpa, 0, NULL, 0) ==
                                              EMULATE_DONE;

        if (unlikely(ret == RET_MMIO_PF_INVALID))
                return kvm_mmu_page_fault(vcpu, gpa, 0, NULL, 0);

        if (unlikely(ret == RET_MMIO_PF_RETRY))
                return 1;

        /* It is the real ept misconfig */
        printk(KERN_ERR "EPT: Misconfiguration.\n");
        printk(KERN_ERR "EPT: GPA: 0x%llx\n", gpa);

        nr_sptes = kvm_mmu_get_spte_hierarchy(vcpu, gpa, sptes);

        for (i = PT64_ROOT_LEVEL; i > PT64_ROOT_LEVEL - nr_sptes; --i)
                ept_misconfig_inspect_spte(vcpu, sptes[i-1], i);

        vcpu->run->exit_reason = KVM_EXIT_UNKNOWN;
        vcpu->run->hw.hardware_exit_reason = EXIT_REASON_EPT_MISCONFIG;

        return 0;
}

static int handle_nmi_window(struct kvm_vcpu *vcpu)
{
        u32 cpu_based_vm_exec_control;

        /* clear pending NMI */
        cpu_based_vm_exec_control = vmcs_read32(CPU_BASED_VM_EXEC_CONTROL);
        cpu_based_vm_exec_control &= ~CPU_BASED_VIRTUAL_NMI_PENDING;
        vmcs_write32(CPU_BASED_VM_EXEC_CONTROL, cpu_based_vm_exec_control);
        ++vcpu->stat.nmi_window_exits;
        kvm_make_request(KVM_REQ_EVENT, vcpu);

        return 1;
}

static int handle_invalid_guest_state(struct kvm_vcpu *vcpu)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);
        enum emulation_result err = EMULATE_DONE;
        int ret = 1;
        u32 cpu_exec_ctrl;
        bool intr_window_requested;
        unsigned count = 130;

        cpu_exec_ctrl = vmcs_read32(CPU_BASED_VM_EXEC_CONTROL);
        intr_window_requested = cpu_exec_ctrl & CPU_BASED_VIRTUAL_INTR_PENDING;

        while (vmx->emulation_required && count-- != 0) {
                if (intr_window_requested && vmx_interrupt_allowed(vcpu))
                        return handle_interrupt_window(&vmx->vcpu);

                if (test_bit(KVM_REQ_EVENT, &vcpu->requests))
                        return 1;

                err = emulate_instruction(vcpu, EMULTYPE_NO_REEXECUTE);

                if (err == EMULATE_USER_EXIT) {
                        ++vcpu->stat.mmio_exits;
                        ret = 0;
                        goto out;
                }

                if (err != EMULATE_DONE) {
                        vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
                        vcpu->run->internal.suberror = KVM_INTERNAL_ERROR_EMULATION;
                        vcpu->run->internal.ndata = 0;
                        return 0;
                }

                if (vcpu->arch.halt_request) {
                        vcpu->arch.halt_request = 0;
                        ret = kvm_emulate_halt(vcpu);
                        goto out;
                }

                if (signal_pending(current))
                        goto out;
                if (need_resched())
                        schedule();
        }

out:
        return ret;
}

static int __grow_ple_window(int val)
{
        if (ple_window_grow < 1)
                return ple_window;

        val = min(val, ple_window_actual_max);

        if (ple_window_grow < ple_window)
                val *= ple_window_grow;
        else
                val += ple_window_grow;

        return val;
}

static int __shrink_ple_window(int val, int modifier, int minimum)
{
        if (modifier < 1)
                return ple_window;

        if (modifier < ple_window)
                val /= modifier;
        else
                val -= modifier;

        return max(val, minimum);
}

static void grow_ple_window(struct kvm_vcpu *vcpu)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);
        int old = vmx->ple_window;

        vmx->ple_window = __grow_ple_window(old);

        if (vmx->ple_window != old)
                vmx->ple_window_dirty = true;

        trace_kvm_ple_window_grow(vcpu->vcpu_id, vmx->ple_window, old);
}

static void shrink_ple_window(struct kvm_vcpu *vcpu)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);
        int old = vmx->ple_window;

        vmx->ple_window = __shrink_ple_window(old,
                                              ple_window_shrink, ple_window);

        if (vmx->ple_window != old)
                vmx->ple_window_dirty = true;

        trace_kvm_ple_window_shrink(vcpu->vcpu_id, vmx->ple_window, old);
}

/*
 * ple_window_actual_max is computed to be one grow_ple_window() below
 * ple_window_max. (See __grow_ple_window for the reason.)
 * This prevents overflows, because ple_window_max is int.
 * ple_window_max effectively rounded down to a multiple of ple_window_grow in
 * this process.
 * ple_window_max is also prevented from setting vmx->ple_window < ple_window.
 */
static void update_ple_window_actual_max(void)
{
        ple_window_actual_max =
                        __shrink_ple_window(max(ple_window_max, ple_window),
                                            ple_window_grow, INT_MIN);
}

/*
 * Indicate a busy-waiting vcpu in spinlock. We do not enable the PAUSE
 * exiting, so only get here on cpu with PAUSE-Loop-Exiting.
 */
static int handle_pause(struct kvm_vcpu *vcpu)
{
        if (ple_gap)
                grow_ple_window(vcpu);

        skip_emulated_instruction(vcpu);
        kvm_vcpu_on_spin(vcpu);

        return 1;
}

static int handle_nop(struct kvm_vcpu *vcpu)
{
        skip_emulated_instruction(vcpu);
        return 1;
}

static int handle_mwait(struct kvm_vcpu *vcpu)
{
        printk_once(KERN_WARNING "kvm: MWAIT instruction emulated as NOP!\n");
        return handle_nop(vcpu);
}

static int handle_monitor(struct kvm_vcpu *vcpu)
{
        printk_once(KERN_WARNING "kvm: MONITOR instruction emulated as NOP!\n");
        return handle_nop(vcpu);
}

/*
 * To run an L2 guest, we need a vmcs02 based on the L1-specified vmcs12.
 * We could reuse a single VMCS for all the L2 guests, but we also want the
 * option to allocate a separate vmcs02 for each separate loaded vmcs12 - this
 * allows keeping them loaded on the processor, and in the future will allow
 * optimizations where prepare_vmcs02 doesn't need to set all the fields on
 * every entry if they never change.
 * So we keep, in vmx->nested.vmcs02_pool, a cache of size VMCS02_POOL_SIZE
 * (>=0) with a vmcs02 for each recently loaded vmcs12s, most recent first.
 *
 * The following functions allocate and free a vmcs02 in this pool.
 */

/* Get a VMCS from the pool to use as vmcs02 for the current vmcs12. */
static struct loaded_vmcs *nested_get_current_vmcs02(struct vcpu_vmx *vmx)
{
        struct vmcs02_list *item;
        list_for_each_entry(item, &vmx->nested.vmcs02_pool, list)
                if (item->vmptr == vmx->nested.current_vmptr) {
                        list_move(&item->list, &vmx->nested.vmcs02_pool);
                        return &item->vmcs02;
                }

        if (vmx->nested.vmcs02_num >= max(VMCS02_POOL_SIZE, 1)) {
                /* Recycle the least recently used VMCS. */
                item = list_entry(vmx->nested.vmcs02_pool.prev,
                        struct vmcs02_list, list);
                item->vmptr = vmx->nested.current_vmptr;
                list_move(&item->list, &vmx->nested.vmcs02_pool);
                return &item->vmcs02;
        }

        /* Create a new VMCS */
        item = kmalloc(sizeof(struct vmcs02_list), GFP_KERNEL);
        if (!item)
                return NULL;
        item->vmcs02.vmcs = alloc_vmcs();
        if (!item->vmcs02.vmcs) {
                kfree(item);
                return NULL;
        }
        loaded_vmcs_init(&item->vmcs02);
        item->vmptr = vmx->nested.current_vmptr;
        list_add(&(item->list), &(vmx->nested.vmcs02_pool));
        vmx->nested.vmcs02_num++;
        return &item->vmcs02;
}

/* Free and remove from pool a vmcs02 saved for a vmcs12 (if there is one) */
static void nested_free_vmcs02(struct vcpu_vmx *vmx, gpa_t vmptr)
{
        struct vmcs02_list *item;
        list_for_each_entry(item, &vmx->nested.vmcs02_pool, list)
                if (item->vmptr == vmptr) {
                        free_loaded_vmcs(&item->vmcs02);
                        list_del(&item->list);
                        kfree(item);
                        vmx->nested.vmcs02_num--;
                        return;
                }
}

/*
 * Free all VMCSs saved for this vcpu, except the one pointed by
 * vmx->loaded_vmcs. We must be running L1, so vmx->loaded_vmcs
 * must be &vmx->vmcs01.
 */
static void nested_free_all_saved_vmcss(struct vcpu_vmx *vmx)
{
        struct vmcs02_list *item, *n;

        WARN_ON(vmx->loaded_vmcs != &vmx->vmcs01);
        list_for_each_entry_safe(item, n, &vmx->nested.vmcs02_pool, list) {
                /*
                 * Something will leak if the above WARN triggers.  Better than
                 * a use-after-free.
                 */
                if (vmx->loaded_vmcs == &item->vmcs02)
                        continue;

                free_loaded_vmcs(&item->vmcs02);
                list_del(&item->list);
                kfree(item);
                vmx->nested.vmcs02_num--;
        }
}

/*
 * The following 3 functions, nested_vmx_succeed()/failValid()/failInvalid(),
 * set the success or error code of an emulated VMX instruction, as specified
 * by Vol 2B, VMX Instruction Reference, "Conventions".
 */
static void nested_vmx_succeed(struct kvm_vcpu *vcpu)
{
        vmx_set_rflags(vcpu, vmx_get_rflags(vcpu)
                        & ~(X86_EFLAGS_CF | X86_EFLAGS_PF | X86_EFLAGS_AF |
                            X86_EFLAGS_ZF | X86_EFLAGS_SF | X86_EFLAGS_OF));
}

static void nested_vmx_failInvalid(struct kvm_vcpu *vcpu)
{
        vmx_set_rflags(vcpu, (vmx_get_rflags(vcpu)
                        & ~(X86_EFLAGS_PF | X86_EFLAGS_AF | X86_EFLAGS_ZF |
                            X86_EFLAGS_SF | X86_EFLAGS_OF))
                        | X86_EFLAGS_CF);
}

static void nested_vmx_failValid(struct kvm_vcpu *vcpu,
                                        u32 vm_instruction_error)
{
        if (to_vmx(vcpu)->nested.current_vmptr == -1ull) {
                /*
                 * failValid writes the error number to the current VMCS, which
                 * can't be done there isn't a current VMCS.
                 */
                nested_vmx_failInvalid(vcpu);
                return;
        }
        vmx_set_rflags(vcpu, (vmx_get_rflags(vcpu)
                        & ~(X86_EFLAGS_CF | X86_EFLAGS_PF | X86_EFLAGS_AF |
                            X86_EFLAGS_SF | X86_EFLAGS_OF))
                        | X86_EFLAGS_ZF);
        get_vmcs12(vcpu)->vm_instruction_error = vm_instruction_error;
        /*
         * We don't need to force a shadow sync because
         * VM_INSTRUCTION_ERROR is not shadowed
         */
}

static enum hrtimer_restart vmx_preemption_timer_fn(struct hrtimer *timer)
{
        struct vcpu_vmx *vmx =
                container_of(timer, struct vcpu_vmx, nested.preemption_timer);

        vmx->nested.preemption_timer_expired = true;
        kvm_make_request(KVM_REQ_EVENT, &vmx->vcpu);
        kvm_vcpu_kick(&vmx->vcpu);

        return HRTIMER_NORESTART;
}

/*
 * Decode the memory-address operand of a vmx instruction, as recorded on an
 * exit caused by such an instruction (run by a guest hypervisor).
 * On success, returns 0. When the operand is invalid, returns 1 and throws
 * #UD or #GP.
 */
static int get_vmx_mem_address(struct kvm_vcpu *vcpu,
                                 unsigned long exit_qualification,
                                 u32 vmx_instruction_info, gva_t *ret)
{
        /*
         * According to Vol. 3B, "Information for VM Exits Due to Instruction
         * Execution", on an exit, vmx_instruction_info holds most of the
         * addressing components of the operand. Only the displacement part
         * is put in exit_qualification (see 3B, "Basic VM-Exit Information").
         * For how an actual address is calculated from all these components,
         * refer to Vol. 1, "Operand Addressing".
         */
        int  scaling = vmx_instruction_info & 3;
        int  addr_size = (vmx_instruction_info >> 7) & 7;
        bool is_reg = vmx_instruction_info & (1u << 10);
        int  seg_reg = (vmx_instruction_info >> 15) & 7;
        int  index_reg = (vmx_instruction_info >> 18) & 0xf;
        bool index_is_valid = !(vmx_instruction_info & (1u << 22));
        int  base_reg       = (vmx_instruction_info >> 23) & 0xf;
        bool base_is_valid  = !(vmx_instruction_info & (1u << 27));

        if (is_reg) {
                kvm_queue_exception(vcpu, UD_VECTOR);
                return 1;
        }

        /* Addr = segment_base + offset */
        /* offset = base + [index * scale] + displacement */
        *ret = vmx_get_segment_base(vcpu, seg_reg);
        if (base_is_valid)
                *ret += kvm_register_read(vcpu, base_reg);
        if (index_is_valid)
                *ret += kvm_register_read(vcpu, index_reg)<<scaling;
        *ret += exit_qualification; /* holds the displacement */

        if (addr_size == 1) /* 32 bit */
                *ret &= 0xffffffff;

        /*
         * TODO: throw #GP (and return 1) in various cases that the VM*
         * instructions require it - e.g., offset beyond segment limit,
         * unusable or unreadable/unwritable segment, non-canonical 64-bit
         * address, and so on. Currently these are not checked.
         */
        return 0;
}

/*
 * This function performs the various checks including
 * - if it's 4KB aligned
 * - No bits beyond the physical address width are set
 * - Returns 0 on success or else 1
 * (Intel SDM Section 30.3)
 */
static int nested_vmx_check_vmptr(struct kvm_vcpu *vcpu, int exit_reason,
                                  gpa_t *vmpointer)
{
        gva_t gva;
        gpa_t vmptr;
        struct x86_exception e;
        struct page *page;
        struct vcpu_vmx *vmx = to_vmx(vcpu);
        int maxphyaddr = cpuid_maxphyaddr(vcpu);

        if (get_vmx_mem_address(vcpu, vmcs_readl(EXIT_QUALIFICATION),
                        vmcs_read32(VMX_INSTRUCTION_INFO), &gva))
                return 1;

        if (kvm_read_guest_virt(&vcpu->arch.emulate_ctxt, gva, &vmptr,
                                sizeof(vmptr), &e)) {
                kvm_inject_page_fault(vcpu, &e);
                return 1;
        }

        switch (exit_reason) {
        case EXIT_REASON_VMON:
                /*
                 * SDM 3: 24.11.5
                 * The first 4 bytes of VMXON region contain the supported
                 * VMCS revision identifier
                 *
                 * Note - IA32_VMX_BASIC[48] will never be 1
                 * for the nested case;
                 * which replaces physical address width with 32
                 *
                 */
                if (!PAGE_ALIGNED(vmptr) || (vmptr >> maxphyaddr)) {
                        nested_vmx_failInvalid(vcpu);
                        skip_emulated_instruction(vcpu);
                        return 1;
                }

                page = nested_get_page(vcpu, vmptr);
                if (page == NULL ||
                    *(u32 *)kmap(page) != VMCS12_REVISION) {
                        nested_vmx_failInvalid(vcpu);
                        kunmap(page);
                        skip_emulated_instruction(vcpu);
                        return 1;
                }
                kunmap(page);
                vmx->nested.vmxon_ptr = vmptr;
                break;
        case EXIT_REASON_VMCLEAR:
                if (!PAGE_ALIGNED(vmptr) || (vmptr >> maxphyaddr)) {
                        nested_vmx_failValid(vcpu,
                                             VMXERR_VMCLEAR_INVALID_ADDRESS);
                        skip_emulated_instruction(vcpu);
                        return 1;
                }

                if (vmptr == vmx->nested.vmxon_ptr) {
                        nested_vmx_failValid(vcpu,
                                             VMXERR_VMCLEAR_VMXON_POINTER);
                        skip_emulated_instruction(vcpu);
                        return 1;
                }
                break;
        case EXIT_REASON_VMPTRLD:
                if (!PAGE_ALIGNED(vmptr) || (vmptr >> maxphyaddr)) {
                        nested_vmx_failValid(vcpu,
                                             VMXERR_VMPTRLD_INVALID_ADDRESS);
                        skip_emulated_instruction(vcpu);
                        return 1;
                }

                if (vmptr == vmx->nested.vmxon_ptr) {
                        nested_vmx_failValid(vcpu,
                                             VMXERR_VMCLEAR_VMXON_POINTER);
                        skip_emulated_instruction(vcpu);
                        return 1;
                }
                break;
        default:
                return 1; /* shouldn't happen */
        }

        if (vmpointer)
                *vmpointer = vmptr;
        return 0;
}

/*
 * Emulate the VMXON instruction.
 * Currently, we just remember that VMX is active, and do not save or even
 * inspect the argument to VMXON (the so-called "VMXON pointer") because we
 * do not currently need to store anything in that guest-allocated memory
 * region. Consequently, VMCLEAR and VMPTRLD also do not verify that the their
 * argument is different from the VMXON pointer (which the spec says they do).
 */
static int handle_vmon(struct kvm_vcpu *vcpu)
{
        struct kvm_segment cs;
        struct vcpu_vmx *vmx = to_vmx(vcpu);
        struct vmcs *shadow_vmcs;
        const u64 VMXON_NEEDED_FEATURES = FEATURE_CONTROL_LOCKED
                | FEATURE_CONTROL_VMXON_ENABLED_OUTSIDE_SMX;

        /* The Intel VMX Instruction Reference lists a bunch of bits that
         * are prerequisite to running VMXON, most notably cr4.VMXE must be
         * set to 1 (see vmx_set_cr4() for when we allow the guest to set this).
         * Otherwise, we should fail with #UD. We test these now:
         */
        if (!kvm_read_cr4_bits(vcpu, X86_CR4_VMXE) ||
            !kvm_read_cr0_bits(vcpu, X86_CR0_PE) ||
            (vmx_get_rflags(vcpu) & X86_EFLAGS_VM)) {
                kvm_queue_exception(vcpu, UD_VECTOR);
                return 1;
        }

        vmx_get_segment(vcpu, &cs, VCPU_SREG_CS);
        if (is_long_mode(vcpu) && !cs.l) {
                kvm_queue_exception(vcpu, UD_VECTOR);
                return 1;
        }

        if (vmx_get_cpl(vcpu)) {
                kvm_inject_gp(vcpu, 0);
                return 1;
        }

        if (nested_vmx_check_vmptr(vcpu, EXIT_REASON_VMON, NULL))
                return 1;

        if (vmx->nested.vmxon) {
                nested_vmx_failValid(vcpu, VMXERR_VMXON_IN_VMX_ROOT_OPERATION);
                skip_emulated_instruction(vcpu);
                return 1;
        }

        if ((vmx->nested.msr_ia32_feature_control & VMXON_NEEDED_FEATURES)
                        != VMXON_NEEDED_FEATURES) {
                kvm_inject_gp(vcpu, 0);
                return 1;
        }

        if (enable_shadow_vmcs) {
                shadow_vmcs = alloc_vmcs();
                if (!shadow_vmcs)
                        return -ENOMEM;
                /* mark vmcs as shadow */
                shadow_vmcs->revision_id |= (1u << 31);
                /* init shadow vmcs */
                vmcs_clear(shadow_vmcs);
                vmx->nested.current_shadow_vmcs = shadow_vmcs;
        }

        INIT_LIST_HEAD(&(vmx->nested.vmcs02_pool));
        vmx->nested.vmcs02_num = 0;

        hrtimer_init(&vmx->nested.preemption_timer, CLOCK_MONOTONIC,
                     HRTIMER_MODE_REL);
        vmx->nested.preemption_timer.function = vmx_preemption_timer_fn;

        vmx->nested.vmxon = true;

        skip_emulated_instruction(vcpu);
        nested_vmx_succeed(vcpu);
        return 1;
}

/*
 * Intel's VMX Instruction Reference specifies a common set of prerequisites
 * for running VMX instructions (except VMXON, whose prerequisites are
 * slightly different). It also specifies what exception to inject otherwise.
 */
static int nested_vmx_check_permission(struct kvm_vcpu *vcpu)
{
        struct kvm_segment cs;
        struct vcpu_vmx *vmx = to_vmx(vcpu);

        if (!vmx->nested.vmxon) {
                kvm_queue_exception(vcpu, UD_VECTOR);
                return 0;
        }

        vmx_get_segment(vcpu, &cs, VCPU_SREG_CS);
        if ((vmx_get_rflags(vcpu) & X86_EFLAGS_VM) ||
            (is_long_mode(vcpu) && !cs.l)) {
                kvm_queue_exception(vcpu, UD_VECTOR);
                return 0;
        }

        if (vmx_get_cpl(vcpu)) {
                kvm_inject_gp(vcpu, 0);
                return 0;
        }

        return 1;
}

static inline void nested_release_vmcs12(struct vcpu_vmx *vmx)
{
        u32 exec_control;
        if (vmx->nested.current_vmptr == -1ull)
                return;

        /* current_vmptr and current_vmcs12 are always set/reset together */
        if (WARN_ON(vmx->nested.current_vmcs12 == NULL))
                return;

        if (enable_shadow_vmcs) {
                /* copy to memory all shadowed fields in case
                   they were modified */
                copy_shadow_to_vmcs12(vmx);
                vmx->nested.sync_shadow_vmcs = false;
                exec_control = vmcs_read32(SECONDARY_VM_EXEC_CONTROL);
                exec_control &= ~SECONDARY_EXEC_SHADOW_VMCS;
                vmcs_write32(SECONDARY_VM_EXEC_CONTROL, exec_control);
                vmcs_write64(VMCS_LINK_POINTER, -1ull);
        }
        kunmap(vmx->nested.current_vmcs12_page);
        nested_release_page(vmx->nested.current_vmcs12_page);
        vmx->nested.current_vmptr = -1ull;
        vmx->nested.current_vmcs12 = NULL;
}

/*
 * Free whatever needs to be freed from vmx->nested when L1 goes down, or
 * just stops using VMX.
 */
static void free_nested(struct vcpu_vmx *vmx)
{
        if (!vmx->nested.vmxon)
                return;

        vmx->nested.vmxon = false;
        nested_release_vmcs12(vmx);
        if (enable_shadow_vmcs)
                free_vmcs(vmx->nested.current_shadow_vmcs);
        /* Unpin physical memory we referred to in current vmcs02 */
        if (vmx->nested.apic_access_page) {
                nested_release_page(vmx->nested.apic_access_page);
                vmx->nested.apic_access_page = NULL;
        }
        if (vmx->nested.virtual_apic_page) {
                nested_release_page(vmx->nested.virtual_apic_page);
                vmx->nested.virtual_apic_page = NULL;
        }

        nested_free_all_saved_vmcss(vmx);
}

/* Emulate the VMXOFF instruction */
static int handle_vmoff(struct kvm_vcpu *vcpu)
{
        if (!nested_vmx_check_permission(vcpu))
                return 1;
        free_nested(to_vmx(vcpu));
        skip_emulated_instruction(vcpu);
        nested_vmx_succeed(vcpu);
        return 1;
}

/* Emulate the VMCLEAR instruction */
static int handle_vmclear(struct kvm_vcpu *vcpu)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);
        gpa_t vmptr;
        struct vmcs12 *vmcs12;
        struct page *page;

        if (!nested_vmx_check_permission(vcpu))
                return 1;

        if (nested_vmx_check_vmptr(vcpu, EXIT_REASON_VMCLEAR, &vmptr))
                return 1;

        if (vmptr == vmx->nested.current_vmptr)
                nested_release_vmcs12(vmx);

        page = nested_get_page(vcpu, vmptr);
        if (page == NULL) {
                /*
                 * For accurate processor emulation, VMCLEAR beyond available
                 * physical memory should do nothing at all. However, it is
                 * possible that a nested vmx bug, not a guest hypervisor bug,
                 * resulted in this case, so let's shut down before doing any
                 * more damage:
                 */
                kvm_make_request(KVM_REQ_TRIPLE_FAULT, vcpu);
                return 1;
        }
        vmcs12 = kmap(page);
        vmcs12->launch_state = 0;
        kunmap(page);
        nested_release_page(page);

        nested_free_vmcs02(vmx, vmptr);

        skip_emulated_instruction(vcpu);
        nested_vmx_succeed(vcpu);
        return 1;
}

static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch);

/* Emulate the VMLAUNCH instruction */
static int handle_vmlaunch(struct kvm_vcpu *vcpu)
{
        return nested_vmx_run(vcpu, true);
}

/* Emulate the VMRESUME instruction */
static int handle_vmresume(struct kvm_vcpu *vcpu)
{

        return nested_vmx_run(vcpu, false);
}

enum vmcs_field_type {
        VMCS_FIELD_TYPE_U16 = 0,
        VMCS_FIELD_TYPE_U64 = 1,
        VMCS_FIELD_TYPE_U32 = 2,
        VMCS_FIELD_TYPE_NATURAL_WIDTH = 3
};

static inline int vmcs_field_type(unsigned long field)
{
        if (0x1 & field)        /* the *_HIGH fields are all 32 bit */
                return VMCS_FIELD_TYPE_U32;
        return (field >> 13) & 0x3 ;
}

static inline int vmcs_field_readonly(unsigned long field)
{
        return (((field >> 10) & 0x3) == 1);
}

/*
 * Read a vmcs12 field. Since these can have varying lengths and we return
 * one type, we chose the biggest type (u64) and zero-extend the return value
 * to that size. Note that the caller, handle_vmread, might need to use only
 * some of the bits we return here (e.g., on 32-bit guests, only 32 bits of
 * 64-bit fields are to be returned).
 */
static inline bool vmcs12_read_any(struct kvm_vcpu *vcpu,
                                        unsigned long field, u64 *ret)
{
        short offset = vmcs_field_to_offset(field);
        char *p;

        if (offset < 0)
                return 0;

        p = ((char *)(get_vmcs12(vcpu))) + offset;

        switch (vmcs_field_type(field)) {
        case VMCS_FIELD_TYPE_NATURAL_WIDTH:
                *ret = *((natural_width *)p);
                return 1;
        case VMCS_FIELD_TYPE_U16:
                *ret = *((u16 *)p);
                return 1;
        case VMCS_FIELD_TYPE_U32:
                *ret = *((u32 *)p);
                return 1;
        case VMCS_FIELD_TYPE_U64:
                *ret = *((u64 *)p);
                return 1;
        default:
                return 0; /* can never happen. */
        }
}


static inline bool vmcs12_write_any(struct kvm_vcpu *vcpu,
                                    unsigned long field, u64 field_value){
        short offset = vmcs_field_to_offset(field);
        char *p = ((char *) get_vmcs12(vcpu)) + offset;
        if (offset < 0)
                return false;

        switch (vmcs_field_type(field)) {
        case VMCS_FIELD_TYPE_U16:
                *(u16 *)p = field_value;
                return true;
        case VMCS_FIELD_TYPE_U32:
                *(u32 *)p = field_value;
                return true;
        case VMCS_FIELD_TYPE_U64:
                *(u64 *)p = field_value;
                return true;
        case VMCS_FIELD_TYPE_NATURAL_WIDTH:
                *(natural_width *)p = field_value;
                return true;
        default:
                return false; /* can never happen. */
        }

}

static void copy_shadow_to_vmcs12(struct vcpu_vmx *vmx)
{
        int i;
        unsigned long field;
        u64 field_value;
        struct vmcs *shadow_vmcs = vmx->nested.current_shadow_vmcs;
        const unsigned long *fields = shadow_read_write_fields;
        const int num_fields = max_shadow_read_write_fields;

        vmcs_load(shadow_vmcs);

        for (i = 0; i < num_fields; i++) {
                field = fields[i];
                switch (vmcs_field_type(field)) {
                case VMCS_FIELD_TYPE_U16:
                        field_value = vmcs_read16(field);
                        break;
                case VMCS_FIELD_TYPE_U32:
                        field_value = vmcs_read32(field);
                        break;
                case VMCS_FIELD_TYPE_U64:
                        field_value = vmcs_read64(field);
                        break;
                case VMCS_FIELD_TYPE_NATURAL_WIDTH:
                        field_value = vmcs_readl(field);
                        break;
                }
                vmcs12_write_any(&vmx->vcpu, field, field_value);
        }

        vmcs_clear(shadow_vmcs);
        vmcs_load(vmx->loaded_vmcs->vmcs);
}

static void copy_vmcs12_to_shadow(struct vcpu_vmx *vmx)
{
        const unsigned long *fields[] = {
                shadow_read_write_fields,
                shadow_read_only_fields
        };
        const int max_fields[] = {
                max_shadow_read_write_fields,
                max_shadow_read_only_fields
        };
        int i, q;
        unsigned long field;
        u64 field_value = 0;
        struct vmcs *shadow_vmcs = vmx->nested.current_shadow_vmcs;

        vmcs_load(shadow_vmcs);

        for (q = 0; q < ARRAY_SIZE(fields); q++) {
                for (i = 0; i < max_fields[q]; i++) {
                        field = fields[q][i];
                        vmcs12_read_any(&vmx->vcpu, field, &field_value);

                        switch (vmcs_field_type(field)) {
                        case VMCS_FIELD_TYPE_U16:
                                vmcs_write16(field, (u16)field_value);
                                break;
                        case VMCS_FIELD_TYPE_U32:
                                vmcs_write32(field, (u32)field_value);
                                break;
                        case VMCS_FIELD_TYPE_U64:
                                vmcs_write64(field, (u64)field_value);
                                break;
                        case VMCS_FIELD_TYPE_NATURAL_WIDTH:
                                vmcs_writel(field, (long)field_value);
                                break;
                        }
                }
        }

        vmcs_clear(shadow_vmcs);
        vmcs_load(vmx->loaded_vmcs->vmcs);
}

/*
 * VMX instructions which assume a current vmcs12 (i.e., that VMPTRLD was
 * used before) all generate the same failure when it is missing.
 */
static int nested_vmx_check_vmcs12(struct kvm_vcpu *vcpu)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);
        if (vmx->nested.current_vmptr == -1ull) {
                nested_vmx_failInvalid(vcpu);
                skip_emulated_instruction(vcpu);
                return 0;
        }
        return 1;
}

static int handle_vmread(struct kvm_vcpu *vcpu)
{
        unsigned long field;
        u64 field_value;
        unsigned long exit_qualification = vmcs_readl(EXIT_QUALIFICATION);
        u32 vmx_instruction_info = vmcs_read32(VMX_INSTRUCTION_INFO);
        gva_t gva = 0;

        if (!nested_vmx_check_permission(vcpu) ||
            !nested_vmx_check_vmcs12(vcpu))
                return 1;

        /* Decode instruction info and find the field to read */
        field = kvm_register_readl(vcpu, (((vmx_instruction_info) >> 28) & 0xf));
        /* Read the field, zero-extended to a u64 field_value */
        if (!vmcs12_read_any(vcpu, field, &field_value)) {
                nested_vmx_failValid(vcpu, VMXERR_UNSUPPORTED_VMCS_COMPONENT);
                skip_emulated_instruction(vcpu);
                return 1;
        }
        /*
         * Now copy part of this value to register or memory, as requested.
         * Note that the number of bits actually copied is 32 or 64 depending
         * on the guest's mode (32 or 64 bit), not on the given field's length.
         */
        if (vmx_instruction_info & (1u << 10)) {
                kvm_register_writel(vcpu, (((vmx_instruction_info) >> 3) & 0xf),
                        field_value);
        } else {
                if (get_vmx_mem_address(vcpu, exit_qualification,
                                vmx_instruction_info, &gva))
                        return 1;
                /* _system ok, as nested_vmx_check_permission verified cpl=0 */
                kvm_write_guest_virt_system(&vcpu->arch.emulate_ctxt, gva,
                             &field_value, (is_long_mode(vcpu) ? 8 : 4), NULL);
        }

        nested_vmx_succeed(vcpu);
        skip_emulated_instruction(vcpu);
        return 1;
}


static int handle_vmwrite(struct kvm_vcpu *vcpu)
{
        unsigned long field;
        gva_t gva;
        unsigned long exit_qualification = vmcs_readl(EXIT_QUALIFICATION);
        u32 vmx_instruction_info = vmcs_read32(VMX_INSTRUCTION_INFO);
        /* The value to write might be 32 or 64 bits, depending on L1's long
         * mode, and eventually we need to write that into a field of several
         * possible lengths. The code below first zero-extends the value to 64
         * bit (field_value), and then copies only the approriate number of
         * bits into the vmcs12 field.
         */
        u64 field_value = 0;
        struct x86_exception e;

        if (!nested_vmx_check_permission(vcpu) ||
            !nested_vmx_check_vmcs12(vcpu))
                return 1;

        if (vmx_instruction_info & (1u << 10))
                field_value = kvm_register_readl(vcpu,
                        (((vmx_instruction_info) >> 3) & 0xf));
        else {
                if (get_vmx_mem_address(vcpu, exit_qualification,
                                vmx_instruction_info, &gva))
                        return 1;
                if (kvm_read_guest_virt(&vcpu->arch.emulate_ctxt, gva,
                           &field_value, (is_64_bit_mode(vcpu) ? 8 : 4), &e)) {
                        kvm_inject_page_fault(vcpu, &e);
                        return 1;
                }
        }


        field = kvm_register_readl(vcpu, (((vmx_instruction_info) >> 28) & 0xf));
        if (vmcs_field_readonly(field)) {
                nested_vmx_failValid(vcpu,
                        VMXERR_VMWRITE_READ_ONLY_VMCS_COMPONENT);
                skip_emulated_instruction(vcpu);
                return 1;
        }

        if (!vmcs12_write_any(vcpu, field, field_value)) {
                nested_vmx_failValid(vcpu, VMXERR_UNSUPPORTED_VMCS_COMPONENT);
                skip_emulated_instruction(vcpu);
                return 1;
        }

        nested_vmx_succeed(vcpu);
        skip_emulated_instruction(vcpu);
        return 1;
}

/* Emulate the VMPTRLD instruction */
static int handle_vmptrld(struct kvm_vcpu *vcpu)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);
        gpa_t vmptr;
        u32 exec_control;

        if (!nested_vmx_check_permission(vcpu))
                return 1;

        if (nested_vmx_check_vmptr(vcpu, EXIT_REASON_VMPTRLD, &vmptr))
                return 1;

        if (vmx->nested.current_vmptr != vmptr) {
                struct vmcs12 *new_vmcs12;
                struct page *page;
                page = nested_get_page(vcpu, vmptr);
                if (page == NULL) {
                        nested_vmx_failInvalid(vcpu);
                        skip_emulated_instruction(vcpu);
                        return 1;
                }
                new_vmcs12 = kmap(page);
                if (new_vmcs12->revision_id != VMCS12_REVISION) {
                        kunmap(page);
                        nested_release_page_clean(page);
                        nested_vmx_failValid(vcpu,
                                VMXERR_VMPTRLD_INCORRECT_VMCS_REVISION_ID);
                        skip_emulated_instruction(vcpu);
                        return 1;
                }

                nested_release_vmcs12(vmx);
                vmx->nested.current_vmptr = vmptr;
                vmx->nested.current_vmcs12 = new_vmcs12;
                vmx->nested.current_vmcs12_page = page;
                if (enable_shadow_vmcs) {
                        exec_control = vmcs_read32(SECONDARY_VM_EXEC_CONTROL);
                        exec_control |= SECONDARY_EXEC_SHADOW_VMCS;
                        vmcs_write32(SECONDARY_VM_EXEC_CONTROL, exec_control);
                        vmcs_write64(VMCS_LINK_POINTER,
                                     __pa(vmx->nested.current_shadow_vmcs));
                        vmx->nested.sync_shadow_vmcs = true;
                }
        }

        nested_vmx_succeed(vcpu);
        skip_emulated_instruction(vcpu);
        return 1;
}

/* Emulate the VMPTRST instruction */
static int handle_vmptrst(struct kvm_vcpu *vcpu)
{
        unsigned long exit_qualification = vmcs_readl(EXIT_QUALIFICATION);
        u32 vmx_instruction_info = vmcs_read32(VMX_INSTRUCTION_INFO);
        gva_t vmcs_gva;
        struct x86_exception e;

        if (!nested_vmx_check_permission(vcpu))
                return 1;

        if (get_vmx_mem_address(vcpu, exit_qualification,
                        vmx_instruction_info, &vmcs_gva))
                return 1;
        /* ok to use *_system, as nested_vmx_check_permission verified cpl=0 */
        if (kvm_write_guest_virt_system(&vcpu->arch.emulate_ctxt, vmcs_gva,
                                 (void *)&to_vmx(vcpu)->nested.current_vmptr,
                                 sizeof(u64), &e)) {
                kvm_inject_page_fault(vcpu, &e);
                return 1;
        }
        nested_vmx_succeed(vcpu);
        skip_emulated_instruction(vcpu);
        return 1;
}

/* Emulate the INVEPT instruction */
static int handle_invept(struct kvm_vcpu *vcpu)
{
        u32 vmx_instruction_info, types;
        unsigned long type;
        gva_t gva;
        struct x86_exception e;
        struct {
                u64 eptp, gpa;
        } operand;

        if (!(nested_vmx_secondary_ctls_high & SECONDARY_EXEC_ENABLE_EPT) ||
            !(nested_vmx_ept_caps & VMX_EPT_INVEPT_BIT)) {
                kvm_queue_exception(vcpu, UD_VECTOR);
                return 1;
        }

        if (!nested_vmx_check_permission(vcpu))
                return 1;

        if (!kvm_read_cr0_bits(vcpu, X86_CR0_PE)) {
                kvm_queue_exception(vcpu, UD_VECTOR);
                return 1;
        }

        vmx_instruction_info = vmcs_read32(VMX_INSTRUCTION_INFO);
        type = kvm_register_readl(vcpu, (vmx_instruction_info >> 28) & 0xf);

        types = (nested_vmx_ept_caps >> VMX_EPT_EXTENT_SHIFT) & 6;

        if (!(types & (1UL << type))) {
                nested_vmx_failValid(vcpu,
                                VMXERR_INVALID_OPERAND_TO_INVEPT_INVVPID);
                return 1;
        }

        /* According to the Intel VMX instruction reference, the memory
         * operand is read even if it isn't needed (e.g., for type==global)
         */
        if (get_vmx_mem_address(vcpu, vmcs_readl(EXIT_QUALIFICATION),
                        vmx_instruction_info, &gva))
                return 1;
        if (kvm_read_guest_virt(&vcpu->arch.emulate_ctxt, gva, &operand,
                                sizeof(operand), &e)) {
                kvm_inject_page_fault(vcpu, &e);
                return 1;
        }

        switch (type) {
        case VMX_EPT_EXTENT_GLOBAL:
                kvm_mmu_sync_roots(vcpu);
                kvm_make_request(KVM_REQ_TLB_FLUSH, vcpu);
                nested_vmx_succeed(vcpu);
                break;
        default:
                /* Trap single context invalidation invept calls */
                BUG_ON(1);
                break;
        }

        skip_emulated_instruction(vcpu);
        return 1;
}

/*
 * The exit handlers return 1 if the exit was handled fully and guest execution
 * may resume.  Otherwise they set the kvm_run parameter to indicate what needs
 * to be done to userspace and return 0.
 */
static int (*const kvm_vmx_exit_handlers[])(struct kvm_vcpu *vcpu) = {
        [EXIT_REASON_EXCEPTION_NMI]           = handle_exception,
        [EXIT_REASON_EXTERNAL_INTERRUPT]      = handle_external_interrupt,
        [EXIT_REASON_TRIPLE_FAULT]            = handle_triple_fault,
        [EXIT_REASON_NMI_WINDOW]              = handle_nmi_window,
        [EXIT_REASON_IO_INSTRUCTION]          = handle_io,
        [EXIT_REASON_CR_ACCESS]               = handle_cr,
        [EXIT_REASON_DR_ACCESS]               = handle_dr,
        [EXIT_REASON_CPUID]                   = handle_cpuid,
        [EXIT_REASON_MSR_READ]                = handle_rdmsr,
        [EXIT_REASON_MSR_WRITE]               = handle_wrmsr,
        [EXIT_REASON_PENDING_INTERRUPT]       = handle_interrupt_window,
        [EXIT_REASON_HLT]                     = handle_halt,
        [EXIT_REASON_INVD]                    = handle_invd,
        [EXIT_REASON_INVLPG]                  = handle_invlpg,
        [EXIT_REASON_RDPMC]                   = handle_rdpmc,
        [EXIT_REASON_VMCALL]                  = handle_vmcall,
        [EXIT_REASON_VMCLEAR]                 = handle_vmclear,
        [EXIT_REASON_VMLAUNCH]                = handle_vmlaunch,
        [EXIT_REASON_VMPTRLD]                 = handle_vmptrld,
        [EXIT_REASON_VMPTRST]                 = handle_vmptrst,
        [EXIT_REASON_VMREAD]                  = handle_vmread,
        [EXIT_REASON_VMRESUME]                = handle_vmresume,
        [EXIT_REASON_VMWRITE]                 = handle_vmwrite,
        [EXIT_REASON_VMOFF]                   = handle_vmoff,
        [EXIT_REASON_VMON]                    = handle_vmon,
        [EXIT_REASON_TPR_BELOW_THRESHOLD]     = handle_tpr_below_threshold,
        [EXIT_REASON_APIC_ACCESS]             = handle_apic_access,
        [EXIT_REASON_APIC_WRITE]              = handle_apic_write,
        [EXIT_REASON_EOI_INDUCED]             = handle_apic_eoi_induced,
        [EXIT_REASON_WBINVD]                  = handle_wbinvd,
        [EXIT_REASON_XSETBV]                  = handle_xsetbv,
        [EXIT_REASON_TASK_SWITCH]             = handle_task_switch,
        [EXIT_REASON_MCE_DURING_VMENTRY]      = handle_machine_check,
        [EXIT_REASON_EPT_VIOLATION]           = handle_ept_violation,
        [EXIT_REASON_EPT_MISCONFIG]           = handle_ept_misconfig,
        [EXIT_REASON_PAUSE_INSTRUCTION]       = handle_pause,
        [EXIT_REASON_MWAIT_INSTRUCTION]       = handle_mwait,
        [EXIT_REASON_MONITOR_INSTRUCTION]     = handle_monitor,
        [EXIT_REASON_INVEPT]                  = handle_invept,
};

static const int kvm_vmx_max_exit_handlers =
        ARRAY_SIZE(kvm_vmx_exit_handlers);

static bool nested_vmx_exit_handled_io(struct kvm_vcpu *vcpu,
                                       struct vmcs12 *vmcs12)
{
        unsigned long exit_qualification;
        gpa_t bitmap, last_bitmap;
        unsigned int port;
        int size;
        u8 b;

        if (!nested_cpu_has(vmcs12, CPU_BASED_USE_IO_BITMAPS))
                return nested_cpu_has(vmcs12, CPU_BASED_UNCOND_IO_EXITING);

        exit_qualification = vmcs_readl(EXIT_QUALIFICATION);

        port = exit_qualification >> 16;
        size = (exit_qualification & 7) + 1;

        last_bitmap = (gpa_t)-1;
        b = -1;

        while (size > 0) {
                if (port < 0x8000)
                        bitmap = vmcs12->io_bitmap_a;
                else if (port < 0x10000)
                        bitmap = vmcs12->io_bitmap_b;
                else
                        return 1;
                bitmap += (port & 0x7fff) / 8;

                if (last_bitmap != bitmap)
                        if (kvm_read_guest(vcpu->kvm, bitmap, &b, 1))
                                return 1;
                if (b & (1 << (port & 7)))
                        return 1;

                port++;
                size--;
                last_bitmap = bitmap;
        }

        return 0;
}

/*
 * Return 1 if we should exit from L2 to L1 to handle an MSR access access,
 * rather than handle it ourselves in L0. I.e., check whether L1 expressed
 * disinterest in the current event (read or write a specific MSR) by using an
 * MSR bitmap. This may be the case even when L0 doesn't use MSR bitmaps.
 */
static bool nested_vmx_exit_handled_msr(struct kvm_vcpu *vcpu,
        struct vmcs12 *vmcs12, u32 exit_reason)
{
        u32 msr_index = vcpu->arch.regs[VCPU_REGS_RCX];
        gpa_t bitmap;

        if (!nested_cpu_has(vmcs12, CPU_BASED_USE_MSR_BITMAPS))
                return 1;

        /*
         * The MSR_BITMAP page is divided into four 1024-byte bitmaps,
         * for the four combinations of read/write and low/high MSR numbers.
         * First we need to figure out which of the four to use:
         */
        bitmap = vmcs12->msr_bitmap;
        if (exit_reason == EXIT_REASON_MSR_WRITE)
                bitmap += 2048;
        if (msr_index >= 0xc0000000) {
                msr_index -= 0xc0000000;
                bitmap += 1024;
        }

        /* Then read the msr_index'th bit from this bitmap: */
        if (msr_index < 1024*8) {
                unsigned char b;
                if (kvm_read_guest(vcpu->kvm, bitmap + msr_index/8, &b, 1))
                        return 1;
                return 1 & (b >> (msr_index & 7));
        } else
                return 1; /* let L1 handle the wrong parameter */
}

/*
 * Return 1 if we should exit from L2 to L1 to handle a CR access exit,
 * rather than handle it ourselves in L0. I.e., check if L1 wanted to
 * intercept (via guest_host_mask etc.) the current event.
 */
static bool nested_vmx_exit_handled_cr(struct kvm_vcpu *vcpu,
        struct vmcs12 *vmcs12)
{
        unsigned long exit_qualification = vmcs_readl(EXIT_QUALIFICATION);
        int cr = exit_qualification & 15;
        int reg = (exit_qualification >> 8) & 15;
        unsigned long val = kvm_register_readl(vcpu, reg);

        switch ((exit_qualification >> 4) & 3) {
        case 0: /* mov to cr */
                switch (cr) {
                case 0:
                        if (vmcs12->cr0_guest_host_mask &
                            (val ^ vmcs12->cr0_read_shadow))
                                return 1;
                        break;
                case 3:
                        if ((vmcs12->cr3_target_count >= 1 &&
                                        vmcs12->cr3_target_value0 == val) ||
                                (vmcs12->cr3_target_count >= 2 &&
                                        vmcs12->cr3_target_value1 == val) ||
                                (vmcs12->cr3_target_count >= 3 &&
                                        vmcs12->cr3_target_value2 == val) ||
                                (vmcs12->cr3_target_count >= 4 &&
                                        vmcs12->cr3_target_value3 == val))
                                return 0;
                        if (nested_cpu_has(vmcs12, CPU_BASED_CR3_LOAD_EXITING))
                                return 1;
                        break;
                case 4:
                        if (vmcs12->cr4_guest_host_mask &
                            (vmcs12->cr4_read_shadow ^ val))
                                return 1;
                        break;
                case 8:
                        if (nested_cpu_has(vmcs12, CPU_BASED_CR8_LOAD_EXITING))
                                return 1;
                        break;
                }
                break;
        case 2: /* clts */
                if ((vmcs12->cr0_guest_host_mask & X86_CR0_TS) &&
                    (vmcs12->cr0_read_shadow & X86_CR0_TS))
                        return 1;
                break;
        case 1: /* mov from cr */
                switch (cr) {
                case 3:
                        if (vmcs12->cpu_based_vm_exec_control &
                            CPU_BASED_CR3_STORE_EXITING)
                                return 1;
                        break;
                case 8:
                        if (vmcs12->cpu_based_vm_exec_control &
                            CPU_BASED_CR8_STORE_EXITING)
                                return 1;
                        break;
                }
                break;
        case 3: /* lmsw */
                /*
                 * lmsw can change bits 1..3 of cr0, and only set bit 0 of
                 * cr0. Other attempted changes are ignored, with no exit.
                 */
                if (vmcs12->cr0_guest_host_mask & 0xe &
                    (val ^ vmcs12->cr0_read_shadow))
                        return 1;
                if ((vmcs12->cr0_guest_host_mask & 0x1) &&
                    !(vmcs12->cr0_read_shadow & 0x1) &&
                    (val & 0x1))
                        return 1;
                break;
        }
        return 0;
}

/*
 * Return 1 if we should exit from L2 to L1 to handle an exit, or 0 if we
 * should handle it ourselves in L0 (and then continue L2). Only call this
 * when in is_guest_mode (L2).
 */
static bool nested_vmx_exit_handled(struct kvm_vcpu *vcpu)
{
        u32 intr_info = vmcs_read32(VM_EXIT_INTR_INFO);
        struct vcpu_vmx *vmx = to_vmx(vcpu);
        struct vmcs12 *vmcs12 = get_vmcs12(vcpu);
        u32 exit_reason = vmx->exit_reason;

        trace_kvm_nested_vmexit(kvm_rip_read(vcpu), exit_reason,
                                vmcs_readl(EXIT_QUALIFICATION),
                                vmx->idt_vectoring_info,
                                intr_info,
                                vmcs_read32(VM_EXIT_INTR_ERROR_CODE),
                                KVM_ISA_VMX);

        if (vmx->nested.nested_run_pending)
                return 0;

        if (unlikely(vmx->fail)) {
                pr_info_ratelimited("%s failed vm entry %x\n", __func__,
                                    vmcs_read32(VM_INSTRUCTION_ERROR));
                return 1;
        }

        switch (exit_reason) {
        case EXIT_REASON_EXCEPTION_NMI:
                if (!is_exception(intr_info))
                        return 0;
                else if (is_page_fault(intr_info))
                        return enable_ept;
                else if (is_no_device(intr_info) &&
                         !(vmcs12->guest_cr0 & X86_CR0_TS))
                        return 0;
                return vmcs12->exception_bitmap &
                                (1u << (intr_info & INTR_INFO_VECTOR_MASK));
        case EXIT_REASON_EXTERNAL_INTERRUPT:
                return 0;
        case EXIT_REASON_TRIPLE_FAULT:
                return 1;
        case EXIT_REASON_PENDING_INTERRUPT:
                return nested_cpu_has(vmcs12, CPU_BASED_VIRTUAL_INTR_PENDING);
        case EXIT_REASON_NMI_WINDOW:
                return nested_cpu_has(vmcs12, CPU_BASED_VIRTUAL_NMI_PENDING);
        case EXIT_REASON_TASK_SWITCH:
                return 1;
        case EXIT_REASON_CPUID:
                if (kvm_register_read(vcpu, VCPU_REGS_RAX) == 0xa)
                        return 0;
                return 1;
        case EXIT_REASON_HLT:
                return nested_cpu_has(vmcs12, CPU_BASED_HLT_EXITING);
        case EXIT_REASON_INVD:
                return 1;
        case EXIT_REASON_INVLPG:
                return nested_cpu_has(vmcs12, CPU_BASED_INVLPG_EXITING);
        case EXIT_REASON_RDPMC:
                return nested_cpu_has(vmcs12, CPU_BASED_RDPMC_EXITING);
        case EXIT_REASON_RDTSC:
                return nested_cpu_has(vmcs12, CPU_BASED_RDTSC_EXITING);
        case EXIT_REASON_VMCALL: case EXIT_REASON_VMCLEAR:
        case EXIT_REASON_VMLAUNCH: case EXIT_REASON_VMPTRLD:
        case EXIT_REASON_VMPTRST: case EXIT_REASON_VMREAD:
        case EXIT_REASON_VMRESUME: case EXIT_REASON_VMWRITE:
        case EXIT_REASON_VMOFF: case EXIT_REASON_VMON:
        case EXIT_REASON_INVEPT:
                /*
                 * VMX instructions trap unconditionally. This allows L1 to
                 * emulate them for its L2 guest, i.e., allows 3-level nesting!
                 */
                return 1;
        case EXIT_REASON_CR_ACCESS:
                return nested_vmx_exit_handled_cr(vcpu, vmcs12);
        case EXIT_REASON_DR_ACCESS:
                return nested_cpu_has(vmcs12, CPU_BASED_MOV_DR_EXITING);
        case EXIT_REASON_IO_INSTRUCTION:
                return nested_vmx_exit_handled_io(vcpu, vmcs12);
        case EXIT_REASON_MSR_READ:
        case EXIT_REASON_MSR_WRITE:
                return nested_vmx_exit_handled_msr(vcpu, vmcs12, exit_reason);
        case EXIT_REASON_INVALID_STATE:
                return 1;
        case EXIT_REASON_MWAIT_INSTRUCTION:
                return nested_cpu_has(vmcs12, CPU_BASED_MWAIT_EXITING);
        case EXIT_REASON_MONITOR_INSTRUCTION:
                return nested_cpu_has(vmcs12, CPU_BASED_MONITOR_EXITING);
        case EXIT_REASON_PAUSE_INSTRUCTION:
                return nested_cpu_has(vmcs12, CPU_BASED_PAUSE_EXITING) ||
                        nested_cpu_has2(vmcs12,
                                SECONDARY_EXEC_PAUSE_LOOP_EXITING);
        case EXIT_REASON_MCE_DURING_VMENTRY:
                return 0;
        case EXIT_REASON_TPR_BELOW_THRESHOLD:
                return nested_cpu_has(vmcs12, CPU_BASED_TPR_SHADOW);
        case EXIT_REASON_APIC_ACCESS:
                return nested_cpu_has2(vmcs12,
                        SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES);
        case EXIT_REASON_EPT_VIOLATION:
                /*
                 * L0 always deals with the EPT violation. If nested EPT is
                 * used, and the nested mmu code discovers that the address is
                 * missing in the guest EPT table (EPT12), the EPT violation
                 * will be injected with nested_ept_inject_page_fault()
                 */
                return 0;
        case EXIT_REASON_EPT_MISCONFIG:
                /*
                 * L2 never uses directly L1's EPT, but rather L0's own EPT
                 * table (shadow on EPT) or a merged EPT table that L0 built
                 * (EPT on EPT). So any problems with the structure of the
                 * table is L0's fault.
                 */
                return 0;
        case EXIT_REASON_WBINVD:
                return nested_cpu_has2(vmcs12, SECONDARY_EXEC_WBINVD_EXITING);
        case EXIT_REASON_XSETBV:
                return 1;
        default:
                return 1;
        }
}

static void vmx_get_exit_info(struct kvm_vcpu *vcpu, u64 *info1, u64 *info2)
{
        *info1 = vmcs_readl(EXIT_QUALIFICATION);
        *info2 = vmcs_read32(VM_EXIT_INTR_INFO);
}

/*
 * The guest has exited.  See if we can fix it or if we need userspace
 * assistance.
 */
static int vmx_handle_exit(struct kvm_vcpu *vcpu)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);
        u32 exit_reason = vmx->exit_reason;
        u32 vectoring_info = vmx->idt_vectoring_info;

        /* If guest state is invalid, start emulating */
        if (vmx->emulation_required)
                return handle_invalid_guest_state(vcpu);

        if (is_guest_mode(vcpu) && nested_vmx_exit_handled(vcpu)) {
                nested_vmx_vmexit(vcpu, exit_reason,
                                  vmcs_read32(VM_EXIT_INTR_INFO),
                                  vmcs_readl(EXIT_QUALIFICATION));
                return 1;
        }

        if (exit_reason & VMX_EXIT_REASONS_FAILED_VMENTRY) {
                vcpu->run->exit_reason = KVM_EXIT_FAIL_ENTRY;
                vcpu->run->fail_entry.hardware_entry_failure_reason
                        = exit_reason;
                return 0;
        }

        if (unlikely(vmx->fail)) {
                vcpu->run->exit_reason = KVM_EXIT_FAIL_ENTRY;
                vcpu->run->fail_entry.hardware_entry_failure_reason
                        = vmcs_read32(VM_INSTRUCTION_ERROR);
                return 0;
        }

        /*
         * Note:
         * Do not try to fix EXIT_REASON_EPT_MISCONFIG if it caused by
         * delivery event since it indicates guest is accessing MMIO.
         * The vm-exit can be triggered again after return to guest that
         * will cause infinite loop.
         */
        if ((vectoring_info & VECTORING_INFO_VALID_MASK) &&
                        (exit_reason != EXIT_REASON_EXCEPTION_NMI &&
                        exit_reason != EXIT_REASON_EPT_VIOLATION &&
                        exit_reason != EXIT_REASON_TASK_SWITCH)) {
                vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
                vcpu->run->internal.suberror = KVM_INTERNAL_ERROR_DELIVERY_EV;
                vcpu->run->internal.ndata = 2;
                vcpu->run->internal.data[0] = vectoring_info;
                vcpu->run->internal.data[1] = exit_reason;
                return 0;
        }

        if (unlikely(!cpu_has_virtual_nmis() && vmx->soft_vnmi_blocked &&
            !(is_guest_mode(vcpu) && nested_cpu_has_virtual_nmis(
                                        get_vmcs12(vcpu))))) {
                if (vmx_interrupt_allowed(vcpu)) {
                        vmx->soft_vnmi_blocked = 0;
                } else if (vmx->vnmi_blocked_time > 1000000000LL &&
                           vcpu->arch.nmi_pending) {
                        /*
                         * This CPU don't support us in finding the end of an
                         * NMI-blocked window if the guest runs with IRQs
                         * disabled. So we pull the trigger after 1 s of
                         * futile waiting, but inform the user about this.
                         */
                        printk(KERN_WARNING "%s: Breaking out of NMI-blocked "
                               "state on VCPU %d after 1 s timeout\n",
                               __func__, vcpu->vcpu_id);
                        vmx->soft_vnmi_blocked = 0;
                }
        }

        if (exit_reason < kvm_vmx_max_exit_handlers
            && kvm_vmx_exit_handlers[exit_reason])
                return kvm_vmx_exit_handlers[exit_reason](vcpu);
        else {
                vcpu->run->exit_reason = KVM_EXIT_UNKNOWN;
                vcpu->run->hw.hardware_exit_reason = exit_reason;
        }
        return 0;
}

static void update_cr8_intercept(struct kvm_vcpu *vcpu, int tpr, int irr)
{
        struct vmcs12 *vmcs12 = get_vmcs12(vcpu);

        if (is_guest_mode(vcpu) &&
                nested_cpu_has(vmcs12, CPU_BASED_TPR_SHADOW))
                return;

        if (irr == -1 || tpr < irr) {
                vmcs_write32(TPR_THRESHOLD, 0);
                return;
        }

        vmcs_write32(TPR_THRESHOLD, irr);
}

static void vmx_set_virtual_x2apic_mode(struct kvm_vcpu *vcpu, bool set)
{
        u32 sec_exec_control;

        /*
         * There is not point to enable virtualize x2apic without enable
         * apicv
         */
        if (!cpu_has_vmx_virtualize_x2apic_mode() ||
                                !vmx_vm_has_apicv(vcpu->kvm))
                return;

        if (!vm_need_tpr_shadow(vcpu->kvm))
                return;

        sec_exec_control = vmcs_read32(SECONDARY_VM_EXEC_CONTROL);

        if (set) {
                sec_exec_control &= ~SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES;
                sec_exec_control |= SECONDARY_EXEC_VIRTUALIZE_X2APIC_MODE;
        } else {
                sec_exec_control &= ~SECONDARY_EXEC_VIRTUALIZE_X2APIC_MODE;
                sec_exec_control |= SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES;
        }
        vmcs_write32(SECONDARY_VM_EXEC_CONTROL, sec_exec_control);

        vmx_set_msr_bitmap(vcpu);
}

static void vmx_set_apic_access_page_addr(struct kvm_vcpu *vcpu, hpa_t hpa)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);

        /*
         * Currently we do not handle the nested case where L2 has an
         * APIC access page of its own; that page is still pinned.
         * Hence, we skip the case where the VCPU is in guest mode _and_
         * L1 prepared an APIC access page for L2.
         *
         * For the case where L1 and L2 share the same APIC access page
         * (flexpriority=Y but SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES clear
         * in the vmcs12), this function will only update either the vmcs01
         * or the vmcs02.  If the former, the vmcs02 will be updated by
         * prepare_vmcs02.  If the latter, the vmcs01 will be updated in
         * the next L2->L1 exit.
         */
        if (!is_guest_mode(vcpu) ||
            !nested_cpu_has2(vmx->nested.current_vmcs12,
                             SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES))
                vmcs_write64(APIC_ACCESS_ADDR, hpa);
}

static void vmx_hwapic_isr_update(struct kvm *kvm, int isr)
{
        u16 status;
        u8 old;

        if (!vmx_vm_has_apicv(kvm))
                return;

        if (isr == -1)
                isr = 0;

        status = vmcs_read16(GUEST_INTR_STATUS);
        old = status >> 8;
        if (isr != old) {
                status &= 0xff;
                status |= isr << 8;
                vmcs_write16(GUEST_INTR_STATUS, status);
        }
}

static void vmx_set_rvi(int vector)
{
        u16 status;
        u8 old;

        status = vmcs_read16(GUEST_INTR_STATUS);
        old = (u8)status & 0xff;
        if ((u8)vector != old) {
                status &= ~0xff;
                status |= (u8)vector;
                vmcs_write16(GUEST_INTR_STATUS, status);
        }
}

static void vmx_hwapic_irr_update(struct kvm_vcpu *vcpu, int max_irr)
{
        if (max_irr == -1)
                return;

        /*
         * If a vmexit is needed, vmx_check_nested_events handles it.
         */
        if (is_guest_mode(vcpu) && nested_exit_on_intr(vcpu))
                return;

        if (!is_guest_mode(vcpu)) {
                vmx_set_rvi(max_irr);
                return;
        }

        /*
         * Fall back to pre-APICv interrupt injection since L2
         * is run without virtual interrupt delivery.
         */
        if (!kvm_event_needs_reinjection(vcpu) &&
            vmx_interrupt_allowed(vcpu)) {
                kvm_queue_interrupt(vcpu, max_irr, false);
                vmx_inject_irq(vcpu);
        }
}

static void vmx_load_eoi_exitmap(struct kvm_vcpu *vcpu, u64 *eoi_exit_bitmap)
{
        if (!vmx_vm_has_apicv(vcpu->kvm))
                return;

        vmcs_write64(EOI_EXIT_BITMAP0, eoi_exit_bitmap[0]);
        vmcs_write64(EOI_EXIT_BITMAP1, eoi_exit_bitmap[1]);
        vmcs_write64(EOI_EXIT_BITMAP2, eoi_exit_bitmap[2]);
        vmcs_write64(EOI_EXIT_BITMAP3, eoi_exit_bitmap[3]);
}

static void vmx_complete_atomic_exit(struct vcpu_vmx *vmx)
{
        u32 exit_intr_info;

        if (!(vmx->exit_reason == EXIT_REASON_MCE_DURING_VMENTRY
              || vmx->exit_reason == EXIT_REASON_EXCEPTION_NMI))
                return;

        vmx->exit_intr_info = vmcs_read32(VM_EXIT_INTR_INFO);
        exit_intr_info = vmx->exit_intr_info;

        /* Handle machine checks before interrupts are enabled */
        if (is_machine_check(exit_intr_info))
                kvm_machine_check();

        /* We need to handle NMIs before interrupts are enabled */
        if ((exit_intr_info & INTR_INFO_INTR_TYPE_MASK) == INTR_TYPE_NMI_INTR &&
            (exit_intr_info & INTR_INFO_VALID_MASK)) {
                kvm_before_handle_nmi(&vmx->vcpu);
                asm("int $2");
                kvm_after_handle_nmi(&vmx->vcpu);
        }
}

static void vmx_handle_external_intr(struct kvm_vcpu *vcpu)
{
        u32 exit_intr_info = vmcs_read32(VM_EXIT_INTR_INFO);

        /*
         * If external interrupt exists, IF bit is set in rflags/eflags on the
         * interrupt stack frame, and interrupt will be enabled on a return
         * from interrupt handler.
         */
        if ((exit_intr_info & (INTR_INFO_VALID_MASK | INTR_INFO_INTR_TYPE_MASK))
                        == (INTR_INFO_VALID_MASK | INTR_TYPE_EXT_INTR)) {
                unsigned int vector;
                unsigned long entry;
                gate_desc *desc;
                struct vcpu_vmx *vmx = to_vmx(vcpu);
#ifdef CONFIG_X86_64
                unsigned long tmp;
#endif

                vector =  exit_intr_info & INTR_INFO_VECTOR_MASK;
                desc = (gate_desc *)vmx->host_idt_base + vector;
                entry = gate_offset(*desc);
                asm volatile(
#ifdef CONFIG_X86_64
                        "mov %%" _ASM_SP ", %[sp]\n\t"
                        "and $0xfffffffffffffff0, %%" _ASM_SP "\n\t"
                        "push $%c[ss]\n\t"
                        "push %[sp]\n\t"
#endif
                        "pushf\n\t"
                        "orl $0x200, (%%" _ASM_SP ")\n\t"
                        __ASM_SIZE(push) " $%c[cs]\n\t"
                        "call *%[entry]\n\t"
                        :
#ifdef CONFIG_X86_64
                        [sp]"=&r"(tmp)
#endif
                        :
                        [entry]"r"(entry),
                        [ss]"i"(__KERNEL_DS),
                        [cs]"i"(__KERNEL_CS)
                        );
        } else
                local_irq_enable();
}

static bool vmx_mpx_supported(void)
{
        return (vmcs_config.vmexit_ctrl & VM_EXIT_CLEAR_BNDCFGS) &&
                (vmcs_config.vmentry_ctrl & VM_ENTRY_LOAD_BNDCFGS);
}

static void vmx_recover_nmi_blocking(struct vcpu_vmx *vmx)
{
        u32 exit_intr_info;
        bool unblock_nmi;
        u8 vector;
        bool idtv_info_valid;

        idtv_info_valid = vmx->idt_vectoring_info & VECTORING_INFO_VALID_MASK;

        if (cpu_has_virtual_nmis()) {
                if (vmx->nmi_known_unmasked)
                        return;
                /*
                 * Can't use vmx->exit_intr_info since we're not sure what
                 * the exit reason is.
                 */
                exit_intr_info = vmcs_read32(VM_EXIT_INTR_INFO);
                unblock_nmi = (exit_intr_info & INTR_INFO_UNBLOCK_NMI) != 0;
                vector = exit_intr_info & INTR_INFO_VECTOR_MASK;
                /*
                 * SDM 3: 27.7.1.2 (September 2008)
                 * Re-set bit "block by NMI" before VM entry if vmexit caused by
                 * a guest IRET fault.
                 * SDM 3: 23.2.2 (September 2008)
                 * Bit 12 is undefined in any of the following cases:
                 *  If the VM exit sets the valid bit in the IDT-vectoring
                 *   information field.
                 *  If the VM exit is due to a double fault.
                 */
                if ((exit_intr_info & INTR_INFO_VALID_MASK) && unblock_nmi &&
                    vector != DF_VECTOR && !idtv_info_valid)
                        vmcs_set_bits(GUEST_INTERRUPTIBILITY_INFO,
                                      GUEST_INTR_STATE_NMI);
                else
                        vmx->nmi_known_unmasked =
                                !(vmcs_read32(GUEST_INTERRUPTIBILITY_INFO)
                                  & GUEST_INTR_STATE_NMI);
        } else if (unlikely(vmx->soft_vnmi_blocked))
                vmx->vnmi_blocked_time +=
                        ktime_to_ns(ktime_sub(ktime_get(), vmx->entry_time));
}

static void __vmx_complete_interrupts(struct kvm_vcpu *vcpu,
                                      u32 idt_vectoring_info,
                                      int instr_len_field,
                                      int error_code_field)
{
        u8 vector;
        int type;
        bool idtv_info_valid;

        idtv_info_valid = idt_vectoring_info & VECTORING_INFO_VALID_MASK;

        vcpu->arch.nmi_injected = false;
        kvm_clear_exception_queue(vcpu);
        kvm_clear_interrupt_queue(vcpu);

        if (!idtv_info_valid)
                return;

        kvm_make_request(KVM_REQ_EVENT, vcpu);

        vector = idt_vectoring_info & VECTORING_INFO_VECTOR_MASK;
        type = idt_vectoring_info & VECTORING_INFO_TYPE_MASK;

        switch (type) {
        case INTR_TYPE_NMI_INTR:
                vcpu->arch.nmi_injected = true;
                /*
                 * SDM 3: 27.7.1.2 (September 2008)
                 * Clear bit "block by NMI" before VM entry if a NMI
                 * delivery faulted.
                 */
                vmx_set_nmi_mask(vcpu, false);
                break;
        case INTR_TYPE_SOFT_EXCEPTION:
                vcpu->arch.event_exit_inst_len = vmcs_read32(instr_len_field);
                /* fall through */
        case INTR_TYPE_HARD_EXCEPTION:
                if (idt_vectoring_info & VECTORING_INFO_DELIVER_CODE_MASK) {
                        u32 err = vmcs_read32(error_code_field);
                        kvm_requeue_exception_e(vcpu, vector, err);
                } else
                        kvm_requeue_exception(vcpu, vector);
                break;
        case INTR_TYPE_SOFT_INTR:
                vcpu->arch.event_exit_inst_len = vmcs_read32(instr_len_field);
                /* fall through */
        case INTR_TYPE_EXT_INTR:
                kvm_queue_interrupt(vcpu, vector, type == INTR_TYPE_SOFT_INTR);
                break;
        default:
                break;
        }
}

static void vmx_complete_interrupts(struct vcpu_vmx *vmx)
{
        __vmx_complete_interrupts(&vmx->vcpu, vmx->idt_vectoring_info,
                                  VM_EXIT_INSTRUCTION_LEN,
                                  IDT_VECTORING_ERROR_CODE);
}

static void vmx_cancel_injection(struct kvm_vcpu *vcpu)
{
        __vmx_complete_interrupts(vcpu,
                                  vmcs_read32(VM_ENTRY_INTR_INFO_FIELD),
                                  VM_ENTRY_INSTRUCTION_LEN,
                                  VM_ENTRY_EXCEPTION_ERROR_CODE);

        vmcs_write32(VM_ENTRY_INTR_INFO_FIELD, 0);
}

static void atomic_switch_perf_msrs(struct vcpu_vmx *vmx)
{
        int i, nr_msrs;
        struct perf_guest_switch_msr *msrs;

        msrs = perf_guest_get_msrs(&nr_msrs);

        if (!msrs)
                return;

        for (i = 0; i < nr_msrs; i++)
                if (msrs[i].host == msrs[i].guest)
                        clear_atomic_switch_msr(vmx, msrs[i].msr);
                else
                        add_atomic_switch_msr(vmx, msrs[i].msr, msrs[i].guest,
                                        msrs[i].host);
}

static void __noclone vmx_vcpu_run(struct kvm_vcpu *vcpu)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);
        unsigned long debugctlmsr, cr4;

        /* Record the guest's net vcpu time for enforced NMI injections. */
        if (unlikely(!cpu_has_virtual_nmis() && vmx->soft_vnmi_blocked))
                vmx->entry_time = ktime_get();

        /* Don't enter VMX if guest state is invalid, let the exit handler
           start emulation until we arrive back to a valid state */
        if (vmx->emulation_required)
                return;

        if (vmx->ple_window_dirty) {
                vmx->ple_window_dirty = false;
                vmcs_write32(PLE_WINDOW, vmx->ple_window);
        }

        if (vmx->nested.sync_shadow_vmcs) {
                copy_vmcs12_to_shadow(vmx);
                vmx->nested.sync_shadow_vmcs = false;
        }

        if (test_bit(VCPU_REGS_RSP, (unsigned long *)&vcpu->arch.regs_dirty))
                vmcs_writel(GUEST_RSP, vcpu->arch.regs[VCPU_REGS_RSP]);
        if (test_bit(VCPU_REGS_RIP, (unsigned long *)&vcpu->arch.regs_dirty))
                vmcs_writel(GUEST_RIP, vcpu->arch.regs[VCPU_REGS_RIP]);

        cr4 = read_cr4();
        if (unlikely(cr4 != vmx->host_state.vmcs_host_cr4)) {
                vmcs_writel(HOST_CR4, cr4);
                vmx->host_state.vmcs_host_cr4 = cr4;
        }

        /* When single-stepping over STI and MOV SS, we must clear the
         * corresponding interruptibility bits in the guest state. Otherwise
         * vmentry fails as it then expects bit 14 (BS) in pending debug
         * exceptions being set, but that's not correct for the guest debugging
         * case. */
        if (vcpu->guest_debug & KVM_GUESTDBG_SINGLESTEP)
                vmx_set_interrupt_shadow(vcpu, 0);

        atomic_switch_perf_msrs(vmx);
        debugctlmsr = get_debugctlmsr();

        vmx->__launched = vmx->loaded_vmcs->launched;
        asm(
                /* Store host registers */
                "push %%" _ASM_DX "; push %%" _ASM_BP ";"
                "push %%" _ASM_CX " \n\t" /* placeholder for guest rcx */
                "push %%" _ASM_CX " \n\t"
                "cmp %%" _ASM_SP ", %c[host_rsp](%0) \n\t"
                "je 1f \n\t"
                "mov %%" _ASM_SP ", %c[host_rsp](%0) \n\t"
                __ex(ASM_VMX_VMWRITE_RSP_RDX) "\n\t"
                "1: \n\t"
                /* Reload cr2 if changed */
                "mov %c[cr2](%0), %%" _ASM_AX " \n\t"
                "mov %%cr2, %%" _ASM_DX " \n\t"
                "cmp %%" _ASM_AX ", %%" _ASM_DX " \n\t"
                "je 2f \n\t"
                "mov %%" _ASM_AX", %%cr2 \n\t"
                "2: \n\t"
                /* Check if vmlaunch of vmresume is needed */
                "cmpl $0, %c[launched](%0) \n\t"
                /* Load guest registers.  Don't clobber flags. */
                "mov %c[rax](%0), %%" _ASM_AX " \n\t"
                "mov %c[rbx](%0), %%" _ASM_BX " \n\t"
                "mov %c[rdx](%0), %%" _ASM_DX " \n\t"
                "mov %c[rsi](%0), %%" _ASM_SI " \n\t"
                "mov %c[rdi](%0), %%" _ASM_DI " \n\t"
                "mov %c[rbp](%0), %%" _ASM_BP " \n\t"
#ifdef CONFIG_X86_64
                "mov %c[r8](%0),  %%r8  \n\t"
                "mov %c[r9](%0),  %%r9  \n\t"
                "mov %c[r10](%0), %%r10 \n\t"
                "mov %c[r11](%0), %%r11 \n\t"
                "mov %c[r12](%0), %%r12 \n\t"
                "mov %c[r13](%0), %%r13 \n\t"
                "mov %c[r14](%0), %%r14 \n\t"
                "mov %c[r15](%0), %%r15 \n\t"
#endif
                "mov %c[rcx](%0), %%" _ASM_CX " \n\t" /* kills %0 (ecx) */

                /* Enter guest mode */
                "jne 1f \n\t"
                __ex(ASM_VMX_VMLAUNCH) "\n\t"
                "jmp 2f \n\t"
                "1: " __ex(ASM_VMX_VMRESUME) "\n\t"
                "2: "
                /* Save guest registers, load host registers, keep flags */
                "mov %0, %c[wordsize](%%" _ASM_SP ") \n\t"
                "pop %0 \n\t"
                "mov %%" _ASM_AX ", %c[rax](%0) \n\t"
                "mov %%" _ASM_BX ", %c[rbx](%0) \n\t"
                __ASM_SIZE(pop) " %c[rcx](%0) \n\t"
                "mov %%" _ASM_DX ", %c[rdx](%0) \n\t"
                "mov %%" _ASM_SI ", %c[rsi](%0) \n\t"
                "mov %%" _ASM_DI ", %c[rdi](%0) \n\t"
                "mov %%" _ASM_BP ", %c[rbp](%0) \n\t"
#ifdef CONFIG_X86_64
                "mov %%r8,  %c[r8](%0) \n\t"
                "mov %%r9,  %c[r9](%0) \n\t"
                "mov %%r10, %c[r10](%0) \n\t"
                "mov %%r11, %c[r11](%0) \n\t"
                "mov %%r12, %c[r12](%0) \n\t"
                "mov %%r13, %c[r13](%0) \n\t"
                "mov %%r14, %c[r14](%0) \n\t"
                "mov %%r15, %c[r15](%0) \n\t"
#endif
                "mov %%cr2, %%" _ASM_AX "   \n\t"
                "mov %%" _ASM_AX ", %c[cr2](%0) \n\t"

                "pop  %%" _ASM_BP "; pop  %%" _ASM_DX " \n\t"
                "setbe %c[fail](%0) \n\t"
                ".pushsection .rodata \n\t"
                ".global vmx_return \n\t"
                "vmx_return: " _ASM_PTR " 2b \n\t"
                ".popsection"
              : : "c"(vmx), "d"((unsigned long)HOST_RSP),
                [launched]"i"(offsetof(struct vcpu_vmx, __launched)),
                [fail]"i"(offsetof(struct vcpu_vmx, fail)),
                [host_rsp]"i"(offsetof(struct vcpu_vmx, host_rsp)),
                [rax]"i"(offsetof(struct vcpu_vmx, vcpu.arch.regs[VCPU_REGS_RAX])),
                [rbx]"i"(offsetof(struct vcpu_vmx, vcpu.arch.regs[VCPU_REGS_RBX])),
                [rcx]"i"(offsetof(struct vcpu_vmx, vcpu.arch.regs[VCPU_REGS_RCX])),
                [rdx]"i"(offsetof(struct vcpu_vmx, vcpu.arch.regs[VCPU_REGS_RDX])),
                [rsi]"i"(offsetof(struct vcpu_vmx, vcpu.arch.regs[VCPU_REGS_RSI])),
                [rdi]"i"(offsetof(struct vcpu_vmx, vcpu.arch.regs[VCPU_REGS_RDI])),
                [rbp]"i"(offsetof(struct vcpu_vmx, vcpu.arch.regs[VCPU_REGS_RBP])),
#ifdef CONFIG_X86_64
                [r8]"i"(offsetof(struct vcpu_vmx, vcpu.arch.regs[VCPU_REGS_R8])),
                [r9]"i"(offsetof(struct vcpu_vmx, vcpu.arch.regs[VCPU_REGS_R9])),
                [r10]"i"(offsetof(struct vcpu_vmx, vcpu.arch.regs[VCPU_REGS_R10])),
                [r11]"i"(offsetof(struct vcpu_vmx, vcpu.arch.regs[VCPU_REGS_R11])),
                [r12]"i"(offsetof(struct vcpu_vmx, vcpu.arch.regs[VCPU_REGS_R12])),
                [r13]"i"(offsetof(struct vcpu_vmx, vcpu.arch.regs[VCPU_REGS_R13])),
                [r14]"i"(offsetof(struct vcpu_vmx, vcpu.arch.regs[VCPU_REGS_R14])),
                [r15]"i"(offsetof(struct vcpu_vmx, vcpu.arch.regs[VCPU_REGS_R15])),
#endif
                [cr2]"i"(offsetof(struct vcpu_vmx, vcpu.arch.cr2)),
                [wordsize]"i"(sizeof(ulong))
              : "cc", "memory"
#ifdef CONFIG_X86_64
                , "rax", "rbx", "rdi", "rsi"
                , "r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15"
#else
                , "eax", "ebx", "edi", "esi"
#endif
              );

        /* MSR_IA32_DEBUGCTLMSR is zeroed on vmexit. Restore it if needed */
        if (debugctlmsr)
                update_debugctlmsr(debugctlmsr);

#ifndef CONFIG_X86_64
        /*
         * The sysexit path does not restore ds/es, so we must set them to
         * a reasonable value ourselves.
         *
         * We can't defer this to vmx_load_host_state() since that function
         * may be executed in interrupt context, which saves and restore segments
         * around it, nullifying its effect.
         */
        loadsegment(ds, __USER_DS);
        loadsegment(es, __USER_DS);
#endif

        vcpu->arch.regs_avail = ~((1 << VCPU_REGS_RIP) | (1 << VCPU_REGS_RSP)
                                  | (1 << VCPU_EXREG_RFLAGS)
                                  | (1 << VCPU_EXREG_PDPTR)
                                  | (1 << VCPU_EXREG_SEGMENTS)
                                  | (1 << VCPU_EXREG_CR3));
        vcpu->arch.regs_dirty = 0;

        vmx->idt_vectoring_info = vmcs_read32(IDT_VECTORING_INFO_FIELD);

        vmx->loaded_vmcs->launched = 1;

        vmx->exit_reason = vmcs_read32(VM_EXIT_REASON);
        trace_kvm_exit(vmx->exit_reason, vcpu, KVM_ISA_VMX);

        /*
         * the KVM_REQ_EVENT optimization bit is only on for one entry, and if
         * we did not inject a still-pending event to L1 now because of
         * nested_run_pending, we need to re-enable this bit.
         */
        if (vmx->nested.nested_run_pending)
                kvm_make_request(KVM_REQ_EVENT, vcpu);

        vmx->nested.nested_run_pending = 0;

        vmx_complete_atomic_exit(vmx);
        vmx_recover_nmi_blocking(vmx);
        vmx_complete_interrupts(vmx);
}

static void vmx_load_vmcs01(struct kvm_vcpu *vcpu)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);
        int cpu;

        if (vmx->loaded_vmcs == &vmx->vmcs01)
                return;

        cpu = get_cpu();
        vmx->loaded_vmcs = &vmx->vmcs01;
        vmx_vcpu_put(vcpu);
        vmx_vcpu_load(vcpu, cpu);
        vcpu->cpu = cpu;
        put_cpu();
}

static void vmx_free_vcpu(struct kvm_vcpu *vcpu)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);

        free_vpid(vmx);
        leave_guest_mode(vcpu);
        vmx_load_vmcs01(vcpu);
        free_nested(vmx);
        free_loaded_vmcs(vmx->loaded_vmcs);
        kfree(vmx->guest_msrs);
        kvm_vcpu_uninit(vcpu);
        kmem_cache_free(kvm_vcpu_cache, vmx);
}

static struct kvm_vcpu *vmx_create_vcpu(struct kvm *kvm, unsigned int id)
{
        int err;
        struct vcpu_vmx *vmx = kmem_cache_zalloc(kvm_vcpu_cache, GFP_KERNEL);
        int cpu;

        if (!vmx)
                return ERR_PTR(-ENOMEM);

        allocate_vpid(vmx);

        err = kvm_vcpu_init(&vmx->vcpu, kvm, id);
        if (err)
                goto free_vcpu;

        vmx->guest_msrs = kmalloc(PAGE_SIZE, GFP_KERNEL);
        BUILD_BUG_ON(ARRAY_SIZE(vmx_msr_index) * sizeof(vmx->guest_msrs[0])
                     > PAGE_SIZE);

        err = -ENOMEM;
        if (!vmx->guest_msrs) {
                goto uninit_vcpu;
        }

        vmx->loaded_vmcs = &vmx->vmcs01;
        vmx->loaded_vmcs->vmcs = alloc_vmcs();
        if (!vmx->loaded_vmcs->vmcs)
                goto free_msrs;
        if (!vmm_exclusive)
                kvm_cpu_vmxon(__pa(per_cpu(vmxarea, raw_smp_processor_id())));
        loaded_vmcs_init(vmx->loaded_vmcs);
        if (!vmm_exclusive)
                kvm_cpu_vmxoff();

        cpu = get_cpu();
        vmx_vcpu_load(&vmx->vcpu, cpu);
        vmx->vcpu.cpu = cpu;
        err = vmx_vcpu_setup(vmx);
        vmx_vcpu_put(&vmx->vcpu);
        put_cpu();
        if (err)
                goto free_vmcs;
        if (vm_need_virtualize_apic_accesses(kvm)) {
                err = alloc_apic_access_page(kvm);
                if (err)
                        goto free_vmcs;
        }

        if (enable_ept) {
                if (!kvm->arch.ept_identity_map_addr)
                        kvm->arch.ept_identity_map_addr =
                                VMX_EPT_IDENTITY_PAGETABLE_ADDR;
                err = init_rmode_identity_map(kvm);
                if (err)
                        goto free_vmcs;
        }

        vmx->nested.current_vmptr = -1ull;
        vmx->nested.current_vmcs12 = NULL;

        return &vmx->vcpu;

free_vmcs:
        free_loaded_vmcs(vmx->loaded_vmcs);
free_msrs:
        kfree(vmx->guest_msrs);
uninit_vcpu:
        kvm_vcpu_uninit(&vmx->vcpu);
free_vcpu:
        free_vpid(vmx);
        kmem_cache_free(kvm_vcpu_cache, vmx);
        return ERR_PTR(err);
}

static void __init vmx_check_processor_compat(void *rtn)
{
        struct vmcs_config vmcs_conf;

        *(int *)rtn = 0;
        if (setup_vmcs_config(&vmcs_conf) < 0)
                *(int *)rtn = -EIO;
        if (memcmp(&vmcs_config, &vmcs_conf, sizeof(struct vmcs_config)) != 0) {
                printk(KERN_ERR "kvm: CPU %d feature inconsistency!\n",
                                smp_processor_id());
                *(int *)rtn = -EIO;
        }
}

static int get_ept_level(void)
{
        return VMX_EPT_DEFAULT_GAW + 1;
}

static u64 vmx_get_mt_mask(struct kvm_vcpu *vcpu, gfn_t gfn, bool is_mmio)
{
        u64 ret;

        /* For VT-d and EPT combination
         * 1. MMIO: always map as UC
         * 2. EPT with VT-d:
         *   a. VT-d without snooping control feature: can't guarantee the
         *      result, try to trust guest.
         *   b. VT-d with snooping control feature: snooping control feature of
         *      VT-d engine can guarantee the cache correctness. Just set it
         *      to WB to keep consistent with host. So the same as item 3.
         * 3. EPT without VT-d: always map as WB and set IPAT=1 to keep
         *    consistent with host MTRR
         */
        if (is_mmio)
                ret = MTRR_TYPE_UNCACHABLE << VMX_EPT_MT_EPTE_SHIFT;
        else if (kvm_arch_has_noncoherent_dma(vcpu->kvm))
                ret = kvm_get_guest_memory_type(vcpu, gfn) <<
                      VMX_EPT_MT_EPTE_SHIFT;
        else
                ret = (MTRR_TYPE_WRBACK << VMX_EPT_MT_EPTE_SHIFT)
                        | VMX_EPT_IPAT_BIT;

        return ret;
}

static int vmx_get_lpage_level(void)
{
        if (enable_ept && !cpu_has_vmx_ept_1g_page())
                return PT_DIRECTORY_LEVEL;
        else
                /* For shadow and EPT supported 1GB page */
                return PT_PDPE_LEVEL;
}

static void vmx_cpuid_update(struct kvm_vcpu *vcpu)
{
        struct kvm_cpuid_entry2 *best;
        struct vcpu_vmx *vmx = to_vmx(vcpu);
        u32 exec_control;

        vmx->rdtscp_enabled = false;
        if (vmx_rdtscp_supported()) {
                exec_control = vmcs_read32(SECONDARY_VM_EXEC_CONTROL);
                if (exec_control & SECONDARY_EXEC_RDTSCP) {
                        best = kvm_find_cpuid_entry(vcpu, 0x80000001, 0);
                        if (best && (best->edx & bit(X86_FEATURE_RDTSCP)))
                                vmx->rdtscp_enabled = true;
                        else {
                                exec_control &= ~SECONDARY_EXEC_RDTSCP;
                                vmcs_write32(SECONDARY_VM_EXEC_CONTROL,
                                                exec_control);
                        }
                }
        }

        /* Exposing INVPCID only when PCID is exposed */
        best = kvm_find_cpuid_entry(vcpu, 0x7, 0);
        if (vmx_invpcid_supported() &&
            best && (best->ebx & bit(X86_FEATURE_INVPCID)) &&
            guest_cpuid_has_pcid(vcpu)) {
                exec_control = vmcs_read32(SECONDARY_VM_EXEC_CONTROL);
                exec_control |= SECONDARY_EXEC_ENABLE_INVPCID;
                vmcs_write32(SECONDARY_VM_EXEC_CONTROL,
                             exec_control);
        } else {
                if (cpu_has_secondary_exec_ctrls()) {
                        exec_control = vmcs_read32(SECONDARY_VM_EXEC_CONTROL);
                        exec_control &= ~SECONDARY_EXEC_ENABLE_INVPCID;
                        vmcs_write32(SECONDARY_VM_EXEC_CONTROL,
                                     exec_control);
                }
                if (best)
                        best->ebx &= ~bit(X86_FEATURE_INVPCID);
        }
}

static void vmx_set_supported_cpuid(u32 func, struct kvm_cpuid_entry2 *entry)
{
        if (func == 1 && nested)
                entry->ecx |= bit(X86_FEATURE_VMX);
}

static void nested_ept_inject_page_fault(struct kvm_vcpu *vcpu,
                struct x86_exception *fault)
{
        struct vmcs12 *vmcs12 = get_vmcs12(vcpu);
        u32 exit_reason;

        if (fault->error_code & PFERR_RSVD_MASK)
                exit_reason = EXIT_REASON_EPT_MISCONFIG;
        else
                exit_reason = EXIT_REASON_EPT_VIOLATION;
        nested_vmx_vmexit(vcpu, exit_reason, 0, vcpu->arch.exit_qualification);
        vmcs12->guest_physical_address = fault->address;
}

/* Callbacks for nested_ept_init_mmu_context: */

static unsigned long nested_ept_get_cr3(struct kvm_vcpu *vcpu)
{
        /* return the page table to be shadowed - in our case, EPT12 */
        return get_vmcs12(vcpu)->ept_pointer;
}

static void nested_ept_init_mmu_context(struct kvm_vcpu *vcpu)
{
        kvm_init_shadow_ept_mmu(vcpu, &vcpu->arch.mmu,
                        nested_vmx_ept_caps & VMX_EPT_EXECUTE_ONLY_BIT);

        vcpu->arch.mmu.set_cr3           = vmx_set_cr3;
        vcpu->arch.mmu.get_cr3           = nested_ept_get_cr3;
        vcpu->arch.mmu.inject_page_fault = nested_ept_inject_page_fault;

        vcpu->arch.walk_mmu              = &vcpu->arch.nested_mmu;
}

static void nested_ept_uninit_mmu_context(struct kvm_vcpu *vcpu)
{
        vcpu->arch.walk_mmu = &vcpu->arch.mmu;
}

static void vmx_inject_page_fault_nested(struct kvm_vcpu *vcpu,
                struct x86_exception *fault)
{
        struct vmcs12 *vmcs12 = get_vmcs12(vcpu);

        WARN_ON(!is_guest_mode(vcpu));

        /* TODO: also check PFEC_MATCH/MASK, not just EB.PF. */
        if (vmcs12->exception_bitmap & (1u << PF_VECTOR))
                nested_vmx_vmexit(vcpu, to_vmx(vcpu)->exit_reason,
                                  vmcs_read32(VM_EXIT_INTR_INFO),
                                  vmcs_readl(EXIT_QUALIFICATION));
        else
                kvm_inject_page_fault(vcpu, fault);
}

static bool nested_get_vmcs12_pages(struct kvm_vcpu *vcpu,
                                        struct vmcs12 *vmcs12)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);

        if (nested_cpu_has2(vmcs12, SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES)) {
                /* TODO: Also verify bits beyond physical address width are 0 */
                if (!PAGE_ALIGNED(vmcs12->apic_access_addr))
                        return false;

                /*
                 * Translate L1 physical address to host physical
                 * address for vmcs02. Keep the page pinned, so this
                 * physical address remains valid. We keep a reference
                 * to it so we can release it later.
                 */
                if (vmx->nested.apic_access_page) /* shouldn't happen */
                        nested_release_page(vmx->nested.apic_access_page);
                vmx->nested.apic_access_page =
                        nested_get_page(vcpu, vmcs12->apic_access_addr);
        }

        if (nested_cpu_has(vmcs12, CPU_BASED_TPR_SHADOW)) {
                /* TODO: Also verify bits beyond physical address width are 0 */
                if (!PAGE_ALIGNED(vmcs12->virtual_apic_page_addr))
                        return false;

                if (vmx->nested.virtual_apic_page) /* shouldn't happen */
                        nested_release_page(vmx->nested.virtual_apic_page);
                vmx->nested.virtual_apic_page =
                        nested_get_page(vcpu, vmcs12->virtual_apic_page_addr);

                /*
                 * Failing the vm entry is _not_ what the processor does
                 * but it's basically the only possibility we have.
                 * We could still enter the guest if CR8 load exits are
                 * enabled, CR8 store exits are enabled, and virtualize APIC
                 * access is disabled; in this case the processor would never
                 * use the TPR shadow and we could simply clear the bit from
                 * the execution control.  But such a configuration is useless,
                 * so let's keep the code simple.
                 */
                if (!vmx->nested.virtual_apic_page)
                        return false;
        }

        return true;
}

static void vmx_start_preemption_timer(struct kvm_vcpu *vcpu)
{
        u64 preemption_timeout = get_vmcs12(vcpu)->vmx_preemption_timer_value;
        struct vcpu_vmx *vmx = to_vmx(vcpu);

        if (vcpu->arch.virtual_tsc_khz == 0)
                return;

        /* Make sure short timeouts reliably trigger an immediate vmexit.
         * hrtimer_start does not guarantee this. */
        if (preemption_timeout <= 1) {
                vmx_preemption_timer_fn(&vmx->nested.preemption_timer);
                return;
        }

        preemption_timeout <<= VMX_MISC_EMULATED_PREEMPTION_TIMER_RATE;
        preemption_timeout *= 1000000;
        do_div(preemption_timeout, vcpu->arch.virtual_tsc_khz);
        hrtimer_start(&vmx->nested.preemption_timer,
                      ns_to_ktime(preemption_timeout), HRTIMER_MODE_REL);
}

/*
 * prepare_vmcs02 is called when the L1 guest hypervisor runs its nested
 * L2 guest. L1 has a vmcs for L2 (vmcs12), and this function "merges" it
 * with L0's requirements for its guest (a.k.a. vmcs01), so we can run the L2
 * guest in a way that will both be appropriate to L1's requests, and our
 * needs. In addition to modifying the active vmcs (which is vmcs02), this
 * function also has additional necessary side-effects, like setting various
 * vcpu->arch fields.
 */
static void prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);
        u32 exec_control;

        vmcs_write16(GUEST_ES_SELECTOR, vmcs12->guest_es_selector);
        vmcs_write16(GUEST_CS_SELECTOR, vmcs12->guest_cs_selector);
        vmcs_write16(GUEST_SS_SELECTOR, vmcs12->guest_ss_selector);
        vmcs_write16(GUEST_DS_SELECTOR, vmcs12->guest_ds_selector);
        vmcs_write16(GUEST_FS_SELECTOR, vmcs12->guest_fs_selector);
        vmcs_write16(GUEST_GS_SELECTOR, vmcs12->guest_gs_selector);
        vmcs_write16(GUEST_LDTR_SELECTOR, vmcs12->guest_ldtr_selector);
        vmcs_write16(GUEST_TR_SELECTOR, vmcs12->guest_tr_selector);
        vmcs_write32(GUEST_ES_LIMIT, vmcs12->guest_es_limit);
        vmcs_write32(GUEST_CS_LIMIT, vmcs12->guest_cs_limit);
        vmcs_write32(GUEST_SS_LIMIT, vmcs12->guest_ss_limit);
        vmcs_write32(GUEST_DS_LIMIT, vmcs12->guest_ds_limit);
        vmcs_write32(GUEST_FS_LIMIT, vmcs12->guest_fs_limit);
        vmcs_write32(GUEST_GS_LIMIT, vmcs12->guest_gs_limit);
        vmcs_write32(GUEST_LDTR_LIMIT, vmcs12->guest_ldtr_limit);
        vmcs_write32(GUEST_TR_LIMIT, vmcs12->guest_tr_limit);
        vmcs_write32(GUEST_GDTR_LIMIT, vmcs12->guest_gdtr_limit);
        vmcs_write32(GUEST_IDTR_LIMIT, vmcs12->guest_idtr_limit);
        vmcs_write32(GUEST_ES_AR_BYTES, vmcs12->guest_es_ar_bytes);
        vmcs_write32(GUEST_CS_AR_BYTES, vmcs12->guest_cs_ar_bytes);
        vmcs_write32(GUEST_SS_AR_BYTES, vmcs12->guest_ss_ar_bytes);
        vmcs_write32(GUEST_DS_AR_BYTES, vmcs12->guest_ds_ar_bytes);
        vmcs_write32(GUEST_FS_AR_BYTES, vmcs12->guest_fs_ar_bytes);
        vmcs_write32(GUEST_GS_AR_BYTES, vmcs12->guest_gs_ar_bytes);
        vmcs_write32(GUEST_LDTR_AR_BYTES, vmcs12->guest_ldtr_ar_bytes);
        vmcs_write32(GUEST_TR_AR_BYTES, vmcs12->guest_tr_ar_bytes);
        vmcs_writel(GUEST_ES_BASE, vmcs12->guest_es_base);
        vmcs_writel(GUEST_CS_BASE, vmcs12->guest_cs_base);
        vmcs_writel(GUEST_SS_BASE, vmcs12->guest_ss_base);
        vmcs_writel(GUEST_DS_BASE, vmcs12->guest_ds_base);
        vmcs_writel(GUEST_FS_BASE, vmcs12->guest_fs_base);
        vmcs_writel(GUEST_GS_BASE, vmcs12->guest_gs_base);
        vmcs_writel(GUEST_LDTR_BASE, vmcs12->guest_ldtr_base);
        vmcs_writel(GUEST_TR_BASE, vmcs12->guest_tr_base);
        vmcs_writel(GUEST_GDTR_BASE, vmcs12->guest_gdtr_base);
        vmcs_writel(GUEST_IDTR_BASE, vmcs12->guest_idtr_base);

        if (vmcs12->vm_entry_controls & VM_ENTRY_LOAD_DEBUG_CONTROLS) {
                kvm_set_dr(vcpu, 7, vmcs12->guest_dr7);
                vmcs_write64(GUEST_IA32_DEBUGCTL, vmcs12->guest_ia32_debugctl);
        } else {
                kvm_set_dr(vcpu, 7, vcpu->arch.dr7);
                vmcs_write64(GUEST_IA32_DEBUGCTL, vmx->nested.vmcs01_debugctl);
        }
        vmcs_write32(VM_ENTRY_INTR_INFO_FIELD,
                vmcs12->vm_entry_intr_info_field);
        vmcs_write32(VM_ENTRY_EXCEPTION_ERROR_CODE,
                vmcs12->vm_entry_exception_error_code);
        vmcs_write32(VM_ENTRY_INSTRUCTION_LEN,
                vmcs12->vm_entry_instruction_len);
        vmcs_write32(GUEST_INTERRUPTIBILITY_INFO,
                vmcs12->guest_interruptibility_info);
        vmcs_write32(GUEST_SYSENTER_CS, vmcs12->guest_sysenter_cs);
        vmx_set_rflags(vcpu, vmcs12->guest_rflags);
        vmcs_writel(GUEST_PENDING_DBG_EXCEPTIONS,
                vmcs12->guest_pending_dbg_exceptions);
        vmcs_writel(GUEST_SYSENTER_ESP, vmcs12->guest_sysenter_esp);
        vmcs_writel(GUEST_SYSENTER_EIP, vmcs12->guest_sysenter_eip);

        vmcs_write64(VMCS_LINK_POINTER, -1ull);

        exec_control = vmcs12->pin_based_vm_exec_control;
        exec_control |= vmcs_config.pin_based_exec_ctrl;
        exec_control &= ~(PIN_BASED_VMX_PREEMPTION_TIMER |
                          PIN_BASED_POSTED_INTR);
        vmcs_write32(PIN_BASED_VM_EXEC_CONTROL, exec_control);

        vmx->nested.preemption_timer_expired = false;
        if (nested_cpu_has_preemption_timer(vmcs12))
                vmx_start_preemption_timer(vcpu);

        /*
         * Whether page-faults are trapped is determined by a combination of
         * 3 settings: PFEC_MASK, PFEC_MATCH and EXCEPTION_BITMAP.PF.
         * If enable_ept, L0 doesn't care about page faults and we should
         * set all of these to L1's desires. However, if !enable_ept, L0 does
         * care about (at least some) page faults, and because it is not easy
         * (if at all possible?) to merge L0 and L1's desires, we simply ask
         * to exit on each and every L2 page fault. This is done by setting
         * MASK=MATCH=0 and (see below) EB.PF=1.
         * Note that below we don't need special code to set EB.PF beyond the
         * "or"ing of the EB of vmcs01 and vmcs12, because when enable_ept,
         * vmcs01's EB.PF is 0 so the "or" will take vmcs12's value, and when
         * !enable_ept, EB.PF is 1, so the "or" will always be 1.
         *
         * A problem with this approach (when !enable_ept) is that L1 may be
         * injected with more page faults than it asked for. This could have
         * caused problems, but in practice existing hypervisors don't care.
         * To fix this, we will need to emulate the PFEC checking (on the L1
         * page tables), using walk_addr(), when injecting PFs to L1.
         */
        vmcs_write32(PAGE_FAULT_ERROR_CODE_MASK,
                enable_ept ? vmcs12->page_fault_error_code_mask : 0);
        vmcs_write32(PAGE_FAULT_ERROR_CODE_MATCH,
                enable_ept ? vmcs12->page_fault_error_code_match : 0);

        if (cpu_has_secondary_exec_ctrls()) {
                exec_control = vmx_secondary_exec_control(vmx);
                if (!vmx->rdtscp_enabled)
                        exec_control &= ~SECONDARY_EXEC_RDTSCP;
                /* Take the following fields only from vmcs12 */
                exec_control &= ~(SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES |
                                  SECONDARY_EXEC_VIRTUAL_INTR_DELIVERY |
                                  SECONDARY_EXEC_APIC_REGISTER_VIRT);
                if (nested_cpu_has(vmcs12,
                                CPU_BASED_ACTIVATE_SECONDARY_CONTROLS))
                        exec_control |= vmcs12->secondary_vm_exec_control;

                if (exec_control & SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES) {
                        /*
                         * If translation failed, no matter: This feature asks
                         * to exit when accessing the given address, and if it
                         * can never be accessed, this feature won't do
                         * anything anyway.
                         */
                        if (!vmx->nested.apic_access_page)
                                exec_control &=
                                  ~SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES;
                        else
                                vmcs_write64(APIC_ACCESS_ADDR,
                                  page_to_phys(vmx->nested.apic_access_page));
                } else if (vm_need_virtualize_apic_accesses(vmx->vcpu.kvm)) {
                        exec_control |=
                                SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES;
                        kvm_vcpu_reload_apic_access_page(vcpu);
                }

                vmcs_write32(SECONDARY_VM_EXEC_CONTROL, exec_control);
        }


        /*
         * Set host-state according to L0's settings (vmcs12 is irrelevant here)
         * Some constant fields are set here by vmx_set_constant_host_state().
         * Other fields are different per CPU, and will be set later when
         * vmx_vcpu_load() is called, and when vmx_save_host_state() is called.
         */
        vmx_set_constant_host_state(vmx);

        /*
         * HOST_RSP is normally set correctly in vmx_vcpu_run() just before
         * entry, but only if the current (host) sp changed from the value
         * we wrote last (vmx->host_rsp). This cache is no longer relevant
         * if we switch vmcs, and rather than hold a separate cache per vmcs,
         * here we just force the write to happen on entry.
         */
        vmx->host_rsp = 0;

        exec_control = vmx_exec_control(vmx); /* L0's desires */
        exec_control &= ~CPU_BASED_VIRTUAL_INTR_PENDING;
        exec_control &= ~CPU_BASED_VIRTUAL_NMI_PENDING;
        exec_control &= ~CPU_BASED_TPR_SHADOW;
        exec_control |= vmcs12->cpu_based_vm_exec_control;

        if (exec_control & CPU_BASED_TPR_SHADOW) {
                vmcs_write64(VIRTUAL_APIC_PAGE_ADDR,
                                page_to_phys(vmx->nested.virtual_apic_page));
                vmcs_write32(TPR_THRESHOLD, vmcs12->tpr_threshold);
        }

        /*
         * Merging of IO and MSR bitmaps not currently supported.
         * Rather, exit every time.
         */
        exec_control &= ~CPU_BASED_USE_MSR_BITMAPS;
        exec_control &= ~CPU_BASED_USE_IO_BITMAPS;
        exec_control |= CPU_BASED_UNCOND_IO_EXITING;

        vmcs_write32(CPU_BASED_VM_EXEC_CONTROL, exec_control);

        /* EXCEPTION_BITMAP and CR0_GUEST_HOST_MASK should basically be the
         * bitwise-or of what L1 wants to trap for L2, and what we want to
         * trap. Note that CR0.TS also needs updating - we do this later.
         */
        update_exception_bitmap(vcpu);
        vcpu->arch.cr0_guest_owned_bits &= ~vmcs12->cr0_guest_host_mask;
        vmcs_writel(CR0_GUEST_HOST_MASK, ~vcpu->arch.cr0_guest_owned_bits);

        /* L2->L1 exit controls are emulated - the hardware exit is to L0 so
         * we should use its exit controls. Note that VM_EXIT_LOAD_IA32_EFER
         * bits are further modified by vmx_set_efer() below.
         */
        vmcs_write32(VM_EXIT_CONTROLS, vmcs_config.vmexit_ctrl);

        /* vmcs12's VM_ENTRY_LOAD_IA32_EFER and VM_ENTRY_IA32E_MODE are
         * emulated by vmx_set_efer(), below.
         */
        vm_entry_controls_init(vmx, 
                (vmcs12->vm_entry_controls & ~VM_ENTRY_LOAD_IA32_EFER &
                        ~VM_ENTRY_IA32E_MODE) |
                (vmcs_config.vmentry_ctrl & ~VM_ENTRY_IA32E_MODE));

        if (vmcs12->vm_entry_controls & VM_ENTRY_LOAD_IA32_PAT) {
                vmcs_write64(GUEST_IA32_PAT, vmcs12->guest_ia32_pat);
                vcpu->arch.pat = vmcs12->guest_ia32_pat;
        } else if (vmcs_config.vmentry_ctrl & VM_ENTRY_LOAD_IA32_PAT)
                vmcs_write64(GUEST_IA32_PAT, vmx->vcpu.arch.pat);


        set_cr4_guest_host_mask(vmx);

        if (vmcs12->vm_entry_controls & VM_ENTRY_LOAD_BNDCFGS)
                vmcs_write64(GUEST_BNDCFGS, vmcs12->guest_bndcfgs);

        if (vmcs12->cpu_based_vm_exec_control & CPU_BASED_USE_TSC_OFFSETING)
                vmcs_write64(TSC_OFFSET,
                        vmx->nested.vmcs01_tsc_offset + vmcs12->tsc_offset);
        else
                vmcs_write64(TSC_OFFSET, vmx->nested.vmcs01_tsc_offset);

        if (enable_vpid) {
                /*
                 * Trivially support vpid by letting L2s share their parent
                 * L1's vpid. TODO: move to a more elaborate solution, giving
                 * each L2 its own vpid and exposing the vpid feature to L1.
                 */
                vmcs_write16(VIRTUAL_PROCESSOR_ID, vmx->vpid);
                vmx_flush_tlb(vcpu);
        }

        if (nested_cpu_has_ept(vmcs12)) {
                kvm_mmu_unload(vcpu);
                nested_ept_init_mmu_context(vcpu);
        }

        if (vmcs12->vm_entry_controls & VM_ENTRY_LOAD_IA32_EFER)
                vcpu->arch.efer = vmcs12->guest_ia32_efer;
        else if (vmcs12->vm_entry_controls & VM_ENTRY_IA32E_MODE)
                vcpu->arch.efer |= (EFER_LMA | EFER_LME);
        else
                vcpu->arch.efer &= ~(EFER_LMA | EFER_LME);
        /* Note: modifies VM_ENTRY/EXIT_CONTROLS and GUEST/HOST_IA32_EFER */
        vmx_set_efer(vcpu, vcpu->arch.efer);

        /*
         * This sets GUEST_CR0 to vmcs12->guest_cr0, with possibly a modified
         * TS bit (for lazy fpu) and bits which we consider mandatory enabled.
         * The CR0_READ_SHADOW is what L2 should have expected to read given
         * the specifications by L1; It's not enough to take
         * vmcs12->cr0_read_shadow because on our cr0_guest_host_mask we we
         * have more bits than L1 expected.
         */
        vmx_set_cr0(vcpu, vmcs12->guest_cr0);
        vmcs_writel(CR0_READ_SHADOW, nested_read_cr0(vmcs12));

        vmx_set_cr4(vcpu, vmcs12->guest_cr4);
        vmcs_writel(CR4_READ_SHADOW, nested_read_cr4(vmcs12));

        /* shadow page tables on either EPT or shadow page tables */
        kvm_set_cr3(vcpu, vmcs12->guest_cr3);
        kvm_mmu_reset_context(vcpu);

        if (!enable_ept)
                vcpu->arch.walk_mmu->inject_page_fault = vmx_inject_page_fault_nested;

        /*
         * L1 may access the L2's PDPTR, so save them to construct vmcs12
         */
        if (enable_ept) {
                vmcs_write64(GUEST_PDPTR0, vmcs12->guest_pdptr0);
                vmcs_write64(GUEST_PDPTR1, vmcs12->guest_pdptr1);
                vmcs_write64(GUEST_PDPTR2, vmcs12->guest_pdptr2);
                vmcs_write64(GUEST_PDPTR3, vmcs12->guest_pdptr3);
        }

        kvm_register_write(vcpu, VCPU_REGS_RSP, vmcs12->guest_rsp);
        kvm_register_write(vcpu, VCPU_REGS_RIP, vmcs12->guest_rip);
}

/*
 * nested_vmx_run() handles a nested entry, i.e., a VMLAUNCH or VMRESUME on L1
 * for running an L2 nested guest.
 */
static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch)
{
        struct vmcs12 *vmcs12;
        struct vcpu_vmx *vmx = to_vmx(vcpu);
        int cpu;
        struct loaded_vmcs *vmcs02;
        bool ia32e;

        if (!nested_vmx_check_permission(vcpu) ||
            !nested_vmx_check_vmcs12(vcpu))
                return 1;

        skip_emulated_instruction(vcpu);
        vmcs12 = get_vmcs12(vcpu);

        if (enable_shadow_vmcs)
                copy_shadow_to_vmcs12(vmx);

        /*
         * The nested entry process starts with enforcing various prerequisites
         * on vmcs12 as required by the Intel SDM, and act appropriately when
         * they fail: As the SDM explains, some conditions should cause the
         * instruction to fail, while others will cause the instruction to seem
         * to succeed, but return an EXIT_REASON_INVALID_STATE.
         * To speed up the normal (success) code path, we should avoid checking
         * for misconfigurations which will anyway be caught by the processor
         * when using the merged vmcs02.
         */
        if (vmcs12->launch_state == launch) {
                nested_vmx_failValid(vcpu,
                        launch ? VMXERR_VMLAUNCH_NONCLEAR_VMCS
                               : VMXERR_VMRESUME_NONLAUNCHED_VMCS);
                return 1;
        }

        if (vmcs12->guest_activity_state != GUEST_ACTIVITY_ACTIVE &&
            vmcs12->guest_activity_state != GUEST_ACTIVITY_HLT) {
                nested_vmx_failValid(vcpu, VMXERR_ENTRY_INVALID_CONTROL_FIELD);
                return 1;
        }

        if ((vmcs12->cpu_based_vm_exec_control & CPU_BASED_USE_MSR_BITMAPS) &&
                        !PAGE_ALIGNED(vmcs12->msr_bitmap)) {
                /*TODO: Also verify bits beyond physical address width are 0*/
                nested_vmx_failValid(vcpu, VMXERR_ENTRY_INVALID_CONTROL_FIELD);
                return 1;
        }

        if (!nested_get_vmcs12_pages(vcpu, vmcs12)) {
                /*TODO: Also verify bits beyond physical address width are 0*/
                nested_vmx_failValid(vcpu, VMXERR_ENTRY_INVALID_CONTROL_FIELD);
                return 1;
        }

        if (vmcs12->vm_entry_msr_load_count > 0 ||
            vmcs12->vm_exit_msr_load_count > 0 ||
            vmcs12->vm_exit_msr_store_count > 0) {
                pr_warn_ratelimited("%s: VMCS MSR_{LOAD,STORE} unsupported\n",
                                    __func__);
                nested_vmx_failValid(vcpu, VMXERR_ENTRY_INVALID_CONTROL_FIELD);
                return 1;
        }

        if (!vmx_control_verify(vmcs12->cpu_based_vm_exec_control,
                                nested_vmx_true_procbased_ctls_low,
                                nested_vmx_procbased_ctls_high) ||
            !vmx_control_verify(vmcs12->secondary_vm_exec_control,
              nested_vmx_secondary_ctls_low, nested_vmx_secondary_ctls_high) ||
            !vmx_control_verify(vmcs12->pin_based_vm_exec_control,
              nested_vmx_pinbased_ctls_low, nested_vmx_pinbased_ctls_high) ||
            !vmx_control_verify(vmcs12->vm_exit_controls,
                                nested_vmx_true_exit_ctls_low,
                                nested_vmx_exit_ctls_high) ||
            !vmx_control_verify(vmcs12->vm_entry_controls,
                                nested_vmx_true_entry_ctls_low,
                                nested_vmx_entry_ctls_high))
        {
                nested_vmx_failValid(vcpu, VMXERR_ENTRY_INVALID_CONTROL_FIELD);
                return 1;
        }

        if (((vmcs12->host_cr0 & VMXON_CR0_ALWAYSON) != VMXON_CR0_ALWAYSON) ||
            ((vmcs12->host_cr4 & VMXON_CR4_ALWAYSON) != VMXON_CR4_ALWAYSON)) {
                nested_vmx_failValid(vcpu,
                        VMXERR_ENTRY_INVALID_HOST_STATE_FIELD);
                return 1;
        }

        if (!nested_cr0_valid(vmcs12, vmcs12->guest_cr0) ||
            ((vmcs12->guest_cr4 & VMXON_CR4_ALWAYSON) != VMXON_CR4_ALWAYSON)) {
                nested_vmx_entry_failure(vcpu, vmcs12,
                        EXIT_REASON_INVALID_STATE, ENTRY_FAIL_DEFAULT);
                return 1;
        }
        if (vmcs12->vmcs_link_pointer != -1ull) {
                nested_vmx_entry_failure(vcpu, vmcs12,
                        EXIT_REASON_INVALID_STATE, ENTRY_FAIL_VMCS_LINK_PTR);
                return 1;
        }

        /*
         * If the load IA32_EFER VM-entry control is 1, the following checks
         * are performed on the field for the IA32_EFER MSR:
         * - Bits reserved in the IA32_EFER MSR must be 0.
         * - Bit 10 (corresponding to IA32_EFER.LMA) must equal the value of
         *   the IA-32e mode guest VM-exit control. It must also be identical
         *   to bit 8 (LME) if bit 31 in the CR0 field (corresponding to
         *   CR0.PG) is 1.
         */
        if (vmcs12->vm_entry_controls & VM_ENTRY_LOAD_IA32_EFER) {
                ia32e = (vmcs12->vm_entry_controls & VM_ENTRY_IA32E_MODE) != 0;
                if (!kvm_valid_efer(vcpu, vmcs12->guest_ia32_efer) ||
                    ia32e != !!(vmcs12->guest_ia32_efer & EFER_LMA) ||
                    ((vmcs12->guest_cr0 & X86_CR0_PG) &&
                     ia32e != !!(vmcs12->guest_ia32_efer & EFER_LME))) {
                        nested_vmx_entry_failure(vcpu, vmcs12,
                                EXIT_REASON_INVALID_STATE, ENTRY_FAIL_DEFAULT);
                        return 1;
                }
        }

        /*
         * If the load IA32_EFER VM-exit control is 1, bits reserved in the
         * IA32_EFER MSR must be 0 in the field for that register. In addition,
         * the values of the LMA and LME bits in the field must each be that of
         * the host address-space size VM-exit control.
         */
        if (vmcs12->vm_exit_controls & VM_EXIT_LOAD_IA32_EFER) {
                ia32e = (vmcs12->vm_exit_controls &
                         VM_EXIT_HOST_ADDR_SPACE_SIZE) != 0;
                if (!kvm_valid_efer(vcpu, vmcs12->host_ia32_efer) ||
                    ia32e != !!(vmcs12->host_ia32_efer & EFER_LMA) ||
                    ia32e != !!(vmcs12->host_ia32_efer & EFER_LME)) {
                        nested_vmx_entry_failure(vcpu, vmcs12,
                                EXIT_REASON_INVALID_STATE, ENTRY_FAIL_DEFAULT);
                        return 1;
                }
        }

        /*
         * We're finally done with prerequisite checking, and can start with
         * the nested entry.
         */

        vmcs02 = nested_get_current_vmcs02(vmx);
        if (!vmcs02)
                return -ENOMEM;

        enter_guest_mode(vcpu);

        vmx->nested.vmcs01_tsc_offset = vmcs_read64(TSC_OFFSET);

        if (!(vmcs12->vm_entry_controls & VM_ENTRY_LOAD_DEBUG_CONTROLS))
                vmx->nested.vmcs01_debugctl = vmcs_read64(GUEST_IA32_DEBUGCTL);

        cpu = get_cpu();
        vmx->loaded_vmcs = vmcs02;
        vmx_vcpu_put(vcpu);
        vmx_vcpu_load(vcpu, cpu);
        vcpu->cpu = cpu;
        put_cpu();

        vmx_segment_cache_clear(vmx);

        vmcs12->launch_state = 1;

        prepare_vmcs02(vcpu, vmcs12);

        if (vmcs12->guest_activity_state == GUEST_ACTIVITY_HLT)
                return kvm_emulate_halt(vcpu);

        vmx->nested.nested_run_pending = 1;

        /*
         * Note no nested_vmx_succeed or nested_vmx_fail here. At this point
         * we are no longer running L1, and VMLAUNCH/VMRESUME has not yet
         * returned as far as L1 is concerned. It will only return (and set
         * the success flag) when L2 exits (see nested_vmx_vmexit()).
         */
        return 1;
}

/*
 * On a nested exit from L2 to L1, vmcs12.guest_cr0 might not be up-to-date
 * because L2 may have changed some cr0 bits directly (CRO_GUEST_HOST_MASK).
 * This function returns the new value we should put in vmcs12.guest_cr0.
 * It's not enough to just return the vmcs02 GUEST_CR0. Rather,
 *  1. Bits that neither L0 nor L1 trapped, were set directly by L2 and are now
 *     available in vmcs02 GUEST_CR0. (Note: It's enough to check that L0
 *     didn't trap the bit, because if L1 did, so would L0).
 *  2. Bits that L1 asked to trap (and therefore L0 also did) could not have
 *     been modified by L2, and L1 knows it. So just leave the old value of
 *     the bit from vmcs12.guest_cr0. Note that the bit from vmcs02 GUEST_CR0
 *     isn't relevant, because if L0 traps this bit it can set it to anything.
 *  3. Bits that L1 didn't trap, but L0 did. L1 believes the guest could have
 *     changed these bits, and therefore they need to be updated, but L0
 *     didn't necessarily allow them to be changed in GUEST_CR0 - and rather
 *     put them in vmcs02 CR0_READ_SHADOW. So take these bits from there.
 */
static inline unsigned long
vmcs12_guest_cr0(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12)
{
        return
        /*1*/   (vmcs_readl(GUEST_CR0) & vcpu->arch.cr0_guest_owned_bits) |
        /*2*/   (vmcs12->guest_cr0 & vmcs12->cr0_guest_host_mask) |
        /*3*/   (vmcs_readl(CR0_READ_SHADOW) & ~(vmcs12->cr0_guest_host_mask |
                        vcpu->arch.cr0_guest_owned_bits));
}

static inline unsigned long
vmcs12_guest_cr4(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12)
{
        return
        /*1*/   (vmcs_readl(GUEST_CR4) & vcpu->arch.cr4_guest_owned_bits) |
        /*2*/   (vmcs12->guest_cr4 & vmcs12->cr4_guest_host_mask) |
        /*3*/   (vmcs_readl(CR4_READ_SHADOW) & ~(vmcs12->cr4_guest_host_mask |
                        vcpu->arch.cr4_guest_owned_bits));
}

static void vmcs12_save_pending_event(struct kvm_vcpu *vcpu,
                                       struct vmcs12 *vmcs12)
{
        u32 idt_vectoring;
        unsigned int nr;

        if (vcpu->arch.exception.pending && vcpu->arch.exception.reinject) {
                nr = vcpu->arch.exception.nr;
                idt_vectoring = nr | VECTORING_INFO_VALID_MASK;

                if (kvm_exception_is_soft(nr)) {
                        vmcs12->vm_exit_instruction_len =
                                vcpu->arch.event_exit_inst_len;
                        idt_vectoring |= INTR_TYPE_SOFT_EXCEPTION;
                } else
                        idt_vectoring |= INTR_TYPE_HARD_EXCEPTION;

                if (vcpu->arch.exception.has_error_code) {
                        idt_vectoring |= VECTORING_INFO_DELIVER_CODE_MASK;
                        vmcs12->idt_vectoring_error_code =
                                vcpu->arch.exception.error_code;
                }

                vmcs12->idt_vectoring_info_field = idt_vectoring;
        } else if (vcpu->arch.nmi_injected) {
                vmcs12->idt_vectoring_info_field =
                        INTR_TYPE_NMI_INTR | INTR_INFO_VALID_MASK | NMI_VECTOR;
        } else if (vcpu->arch.interrupt.pending) {
                nr = vcpu->arch.interrupt.nr;
                idt_vectoring = nr | VECTORING_INFO_VALID_MASK;

                if (vcpu->arch.interrupt.soft) {
                        idt_vectoring |= INTR_TYPE_SOFT_INTR;
                        vmcs12->vm_entry_instruction_len =
                                vcpu->arch.event_exit_inst_len;
                } else
                        idt_vectoring |= INTR_TYPE_EXT_INTR;

                vmcs12->idt_vectoring_info_field = idt_vectoring;
        }
}

static int vmx_check_nested_events(struct kvm_vcpu *vcpu, bool external_intr)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);

        if (nested_cpu_has_preemption_timer(get_vmcs12(vcpu)) &&
            vmx->nested.preemption_timer_expired) {
                if (vmx->nested.nested_run_pending)
                        return -EBUSY;
                nested_vmx_vmexit(vcpu, EXIT_REASON_PREEMPTION_TIMER, 0, 0);
                return 0;
        }

        if (vcpu->arch.nmi_pending && nested_exit_on_nmi(vcpu)) {
                if (vmx->nested.nested_run_pending ||
                    vcpu->arch.interrupt.pending)
                        return -EBUSY;
                nested_vmx_vmexit(vcpu, EXIT_REASON_EXCEPTION_NMI,
                                  NMI_VECTOR | INTR_TYPE_NMI_INTR |
                                  INTR_INFO_VALID_MASK, 0);
                /*
                 * The NMI-triggered VM exit counts as injection:
                 * clear this one and block further NMIs.
                 */
                vcpu->arch.nmi_pending = 0;
                vmx_set_nmi_mask(vcpu, true);
                return 0;
        }

        if ((kvm_cpu_has_interrupt(vcpu) || external_intr) &&
            nested_exit_on_intr(vcpu)) {
                if (vmx->nested.nested_run_pending)
                        return -EBUSY;
                nested_vmx_vmexit(vcpu, EXIT_REASON_EXTERNAL_INTERRUPT, 0, 0);
        }

        return 0;
}

static u32 vmx_get_preemption_timer_value(struct kvm_vcpu *vcpu)
{
        ktime_t remaining =
                hrtimer_get_remaining(&to_vmx(vcpu)->nested.preemption_timer);
        u64 value;

        if (ktime_to_ns(remaining) <= 0)
                return 0;

        value = ktime_to_ns(remaining) * vcpu->arch.virtual_tsc_khz;
        do_div(value, 1000000);
        return value >> VMX_MISC_EMULATED_PREEMPTION_TIMER_RATE;
}

/*
 * prepare_vmcs12 is part of what we need to do when the nested L2 guest exits
 * and we want to prepare to run its L1 parent. L1 keeps a vmcs for L2 (vmcs12),
 * and this function updates it to reflect the changes to the guest state while
 * L2 was running (and perhaps made some exits which were handled directly by L0
 * without going back to L1), and to reflect the exit reason.
 * Note that we do not have to copy here all VMCS fields, just those that
 * could have changed by the L2 guest or the exit - i.e., the guest-state and
 * exit-information fields only. Other fields are modified by L1 with VMWRITE,
 * which already writes to vmcs12 directly.
 */
static void prepare_vmcs12(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12,
                           u32 exit_reason, u32 exit_intr_info,
                           unsigned long exit_qualification)
{
        /* update guest state fields: */
        vmcs12->guest_cr0 = vmcs12_guest_cr0(vcpu, vmcs12);
        vmcs12->guest_cr4 = vmcs12_guest_cr4(vcpu, vmcs12);

        vmcs12->guest_rsp = kvm_register_read(vcpu, VCPU_REGS_RSP);
        vmcs12->guest_rip = kvm_register_read(vcpu, VCPU_REGS_RIP);
        vmcs12->guest_rflags = vmcs_readl(GUEST_RFLAGS);

        vmcs12->guest_es_selector = vmcs_read16(GUEST_ES_SELECTOR);
        vmcs12->guest_cs_selector = vmcs_read16(GUEST_CS_SELECTOR);
        vmcs12->guest_ss_selector = vmcs_read16(GUEST_SS_SELECTOR);
        vmcs12->guest_ds_selector = vmcs_read16(GUEST_DS_SELECTOR);
        vmcs12->guest_fs_selector = vmcs_read16(GUEST_FS_SELECTOR);
        vmcs12->guest_gs_selector = vmcs_read16(GUEST_GS_SELECTOR);
        vmcs12->guest_ldtr_selector = vmcs_read16(GUEST_LDTR_SELECTOR);
        vmcs12->guest_tr_selector = vmcs_read16(GUEST_TR_SELECTOR);
        vmcs12->guest_es_limit = vmcs_read32(GUEST_ES_LIMIT);
        vmcs12->guest_cs_limit = vmcs_read32(GUEST_CS_LIMIT);
        vmcs12->guest_ss_limit = vmcs_read32(GUEST_SS_LIMIT);
        vmcs12->guest_ds_limit = vmcs_read32(GUEST_DS_LIMIT);
        vmcs12->guest_fs_limit = vmcs_read32(GUEST_FS_LIMIT);
        vmcs12->guest_gs_limit = vmcs_read32(GUEST_GS_LIMIT);
        vmcs12->guest_ldtr_limit = vmcs_read32(GUEST_LDTR_LIMIT);
        vmcs12->guest_tr_limit = vmcs_read32(GUEST_TR_LIMIT);
        vmcs12->guest_gdtr_limit = vmcs_read32(GUEST_GDTR_LIMIT);
        vmcs12->guest_idtr_limit = vmcs_read32(GUEST_IDTR_LIMIT);
        vmcs12->guest_es_ar_bytes = vmcs_read32(GUEST_ES_AR_BYTES);
        vmcs12->guest_cs_ar_bytes = vmcs_read32(GUEST_CS_AR_BYTES);
        vmcs12->guest_ss_ar_bytes = vmcs_read32(GUEST_SS_AR_BYTES);
        vmcs12->guest_ds_ar_bytes = vmcs_read32(GUEST_DS_AR_BYTES);
        vmcs12->guest_fs_ar_bytes = vmcs_read32(GUEST_FS_AR_BYTES);
        vmcs12->guest_gs_ar_bytes = vmcs_read32(GUEST_GS_AR_BYTES);
        vmcs12->guest_ldtr_ar_bytes = vmcs_read32(GUEST_LDTR_AR_BYTES);
        vmcs12->guest_tr_ar_bytes = vmcs_read32(GUEST_TR_AR_BYTES);
        vmcs12->guest_es_base = vmcs_readl(GUEST_ES_BASE);
        vmcs12->guest_cs_base = vmcs_readl(GUEST_CS_BASE);
        vmcs12->guest_ss_base = vmcs_readl(GUEST_SS_BASE);
        vmcs12->guest_ds_base = vmcs_readl(GUEST_DS_BASE);
        vmcs12->guest_fs_base = vmcs_readl(GUEST_FS_BASE);
        vmcs12->guest_gs_base = vmcs_readl(GUEST_GS_BASE);
        vmcs12->guest_ldtr_base = vmcs_readl(GUEST_LDTR_BASE);
        vmcs12->guest_tr_base = vmcs_readl(GUEST_TR_BASE);
        vmcs12->guest_gdtr_base = vmcs_readl(GUEST_GDTR_BASE);
        vmcs12->guest_idtr_base = vmcs_readl(GUEST_IDTR_BASE);

        vmcs12->guest_interruptibility_info =
                vmcs_read32(GUEST_INTERRUPTIBILITY_INFO);
        vmcs12->guest_pending_dbg_exceptions =
                vmcs_readl(GUEST_PENDING_DBG_EXCEPTIONS);
        if (vcpu->arch.mp_state == KVM_MP_STATE_HALTED)
                vmcs12->guest_activity_state = GUEST_ACTIVITY_HLT;
        else
                vmcs12->guest_activity_state = GUEST_ACTIVITY_ACTIVE;

        if (nested_cpu_has_preemption_timer(vmcs12)) {
                if (vmcs12->vm_exit_controls &
                    VM_EXIT_SAVE_VMX_PREEMPTION_TIMER)
                        vmcs12->vmx_preemption_timer_value =
                                vmx_get_preemption_timer_value(vcpu);
                hrtimer_cancel(&to_vmx(vcpu)->nested.preemption_timer);
        }

        /*
         * In some cases (usually, nested EPT), L2 is allowed to change its
         * own CR3 without exiting. If it has changed it, we must keep it.
         * Of course, if L0 is using shadow page tables, GUEST_CR3 was defined
         * by L0, not L1 or L2, so we mustn't unconditionally copy it to vmcs12.
         *
         * Additionally, restore L2's PDPTR to vmcs12.
         */
        if (enable_ept) {
                vmcs12->guest_cr3 = vmcs_read64(GUEST_CR3);
                vmcs12->guest_pdptr0 = vmcs_read64(GUEST_PDPTR0);
                vmcs12->guest_pdptr1 = vmcs_read64(GUEST_PDPTR1);
                vmcs12->guest_pdptr2 = vmcs_read64(GUEST_PDPTR2);
                vmcs12->guest_pdptr3 = vmcs_read64(GUEST_PDPTR3);
        }

        vmcs12->vm_entry_controls =
                (vmcs12->vm_entry_controls & ~VM_ENTRY_IA32E_MODE) |
                (vm_entry_controls_get(to_vmx(vcpu)) & VM_ENTRY_IA32E_MODE);

        if (vmcs12->vm_exit_controls & VM_EXIT_SAVE_DEBUG_CONTROLS) {
                kvm_get_dr(vcpu, 7, (unsigned long *)&vmcs12->guest_dr7);
                vmcs12->guest_ia32_debugctl = vmcs_read64(GUEST_IA32_DEBUGCTL);
        }

        /* TODO: These cannot have changed unless we have MSR bitmaps and
         * the relevant bit asks not to trap the change */
        if (vmcs12->vm_exit_controls & VM_EXIT_SAVE_IA32_PAT)
                vmcs12->guest_ia32_pat = vmcs_read64(GUEST_IA32_PAT);
        if (vmcs12->vm_exit_controls & VM_EXIT_SAVE_IA32_EFER)
                vmcs12->guest_ia32_efer = vcpu->arch.efer;
        vmcs12->guest_sysenter_cs = vmcs_read32(GUEST_SYSENTER_CS);
        vmcs12->guest_sysenter_esp = vmcs_readl(GUEST_SYSENTER_ESP);
        vmcs12->guest_sysenter_eip = vmcs_readl(GUEST_SYSENTER_EIP);
        if (vmx_mpx_supported())
                vmcs12->guest_bndcfgs = vmcs_read64(GUEST_BNDCFGS);

        /* update exit information fields: */

        vmcs12->vm_exit_reason = exit_reason;
        vmcs12->exit_qualification = exit_qualification;

        vmcs12->vm_exit_intr_info = exit_intr_info;
        if ((vmcs12->vm_exit_intr_info &
             (INTR_INFO_VALID_MASK | INTR_INFO_DELIVER_CODE_MASK)) ==
            (INTR_INFO_VALID_MASK | INTR_INFO_DELIVER_CODE_MASK))
                vmcs12->vm_exit_intr_error_code =
                        vmcs_read32(VM_EXIT_INTR_ERROR_CODE);
        vmcs12->idt_vectoring_info_field = 0;
        vmcs12->vm_exit_instruction_len = vmcs_read32(VM_EXIT_INSTRUCTION_LEN);
        vmcs12->vmx_instruction_info = vmcs_read32(VMX_INSTRUCTION_INFO);

        if (!(vmcs12->vm_exit_reason & VMX_EXIT_REASONS_FAILED_VMENTRY)) {
                /* vm_entry_intr_info_field is cleared on exit. Emulate this
                 * instead of reading the real value. */
                vmcs12->vm_entry_intr_info_field &= ~INTR_INFO_VALID_MASK;

                /*
                 * Transfer the event that L0 or L1 may wanted to inject into
                 * L2 to IDT_VECTORING_INFO_FIELD.
                 */
                vmcs12_save_pending_event(vcpu, vmcs12);
        }

        /*
         * Drop what we picked up for L2 via vmx_complete_interrupts. It is
         * preserved above and would only end up incorrectly in L1.
         */
        vcpu->arch.nmi_injected = false;
        kvm_clear_exception_queue(vcpu);
        kvm_clear_interrupt_queue(vcpu);
}

/*
 * A part of what we need to when the nested L2 guest exits and we want to
 * run its L1 parent, is to reset L1's guest state to the host state specified
 * in vmcs12.
 * This function is to be called not only on normal nested exit, but also on
 * a nested entry failure, as explained in Intel's spec, 3B.23.7 ("VM-Entry
 * Failures During or After Loading Guest State").
 * This function should be called when the active VMCS is L1's (vmcs01).
 */
static void load_vmcs12_host_state(struct kvm_vcpu *vcpu,
                                   struct vmcs12 *vmcs12)
{
        struct kvm_segment seg;

        if (vmcs12->vm_exit_controls & VM_EXIT_LOAD_IA32_EFER)
                vcpu->arch.efer = vmcs12->host_ia32_efer;
        else if (vmcs12->vm_exit_controls & VM_EXIT_HOST_ADDR_SPACE_SIZE)
                vcpu->arch.efer |= (EFER_LMA | EFER_LME);
        else
                vcpu->arch.efer &= ~(EFER_LMA | EFER_LME);
        vmx_set_efer(vcpu, vcpu->arch.efer);

        kvm_register_write(vcpu, VCPU_REGS_RSP, vmcs12->host_rsp);
        kvm_register_write(vcpu, VCPU_REGS_RIP, vmcs12->host_rip);
        vmx_set_rflags(vcpu, X86_EFLAGS_FIXED);
        /*
         * Note that calling vmx_set_cr0 is important, even if cr0 hasn't
         * actually changed, because it depends on the current state of
         * fpu_active (which may have changed).
         * Note that vmx_set_cr0 refers to efer set above.
         */
        vmx_set_cr0(vcpu, vmcs12->host_cr0);
        /*
         * If we did fpu_activate()/fpu_deactivate() during L2's run, we need
         * to apply the same changes to L1's vmcs. We just set cr0 correctly,
         * but we also need to update cr0_guest_host_mask and exception_bitmap.
         */
        update_exception_bitmap(vcpu);
        vcpu->arch.cr0_guest_owned_bits = (vcpu->fpu_active ? X86_CR0_TS : 0);
        vmcs_writel(CR0_GUEST_HOST_MASK, ~vcpu->arch.cr0_guest_owned_bits);

        /*
         * Note that CR4_GUEST_HOST_MASK is already set in the original vmcs01
         * (KVM doesn't change it)- no reason to call set_cr4_guest_host_mask();
         */
        vcpu->arch.cr4_guest_owned_bits = ~vmcs_readl(CR4_GUEST_HOST_MASK);
        kvm_set_cr4(vcpu, vmcs12->host_cr4);

        nested_ept_uninit_mmu_context(vcpu);

        kvm_set_cr3(vcpu, vmcs12->host_cr3);
        kvm_mmu_reset_context(vcpu);

        if (!enable_ept)
                vcpu->arch.walk_mmu->inject_page_fault = kvm_inject_page_fault;

        if (enable_vpid) {
                /*
                 * Trivially support vpid by letting L2s share their parent
                 * L1's vpid. TODO: move to a more elaborate solution, giving
                 * each L2 its own vpid and exposing the vpid feature to L1.
                 */
                vmx_flush_tlb(vcpu);
        }


        vmcs_write32(GUEST_SYSENTER_CS, vmcs12->host_ia32_sysenter_cs);
        vmcs_writel(GUEST_SYSENTER_ESP, vmcs12->host_ia32_sysenter_esp);
        vmcs_writel(GUEST_SYSENTER_EIP, vmcs12->host_ia32_sysenter_eip);
        vmcs_writel(GUEST_IDTR_BASE, vmcs12->host_idtr_base);
        vmcs_writel(GUEST_GDTR_BASE, vmcs12->host_gdtr_base);

        /* If not VM_EXIT_CLEAR_BNDCFGS, the L2 value propagates to L1.  */
        if (vmcs12->vm_exit_controls & VM_EXIT_CLEAR_BNDCFGS)
                vmcs_write64(GUEST_BNDCFGS, 0);

        if (vmcs12->vm_exit_controls & VM_EXIT_LOAD_IA32_PAT) {
                vmcs_write64(GUEST_IA32_PAT, vmcs12->host_ia32_pat);
                vcpu->arch.pat = vmcs12->host_ia32_pat;
        }
        if (vmcs12->vm_exit_controls & VM_EXIT_LOAD_IA32_PERF_GLOBAL_CTRL)
                vmcs_write64(GUEST_IA32_PERF_GLOBAL_CTRL,
                        vmcs12->host_ia32_perf_global_ctrl);

        /* Set L1 segment info according to Intel SDM
            27.5.2 Loading Host Segment and Descriptor-Table Registers */
        seg = (struct kvm_segment) {
                .base = 0,
                .limit = 0xFFFFFFFF,
                .selector = vmcs12->host_cs_selector,
                .type = 11,
                .present = 1,
                .s = 1,
                .g = 1
        };
        if (vmcs12->vm_exit_controls & VM_EXIT_HOST_ADDR_SPACE_SIZE)
                seg.l = 1;
        else
                seg.db = 1;
        vmx_set_segment(vcpu, &seg, VCPU_SREG_CS);
        seg = (struct kvm_segment) {
                .base = 0,
                .limit = 0xFFFFFFFF,
                .type = 3,
                .present = 1,
                .s = 1,
                .db = 1,
                .g = 1
        };
        seg.selector = vmcs12->host_ds_selector;
        vmx_set_segment(vcpu, &seg, VCPU_SREG_DS);
        seg.selector = vmcs12->host_es_selector;
        vmx_set_segment(vcpu, &seg, VCPU_SREG_ES);
        seg.selector = vmcs12->host_ss_selector;
        vmx_set_segment(vcpu, &seg, VCPU_SREG_SS);
        seg.selector = vmcs12->host_fs_selector;
        seg.base = vmcs12->host_fs_base;
        vmx_set_segment(vcpu, &seg, VCPU_SREG_FS);
        seg.selector = vmcs12->host_gs_selector;
        seg.base = vmcs12->host_gs_base;
        vmx_set_segment(vcpu, &seg, VCPU_SREG_GS);
        seg = (struct kvm_segment) {
                .base = vmcs12->host_tr_base,
                .limit = 0x67,
                .selector = vmcs12->host_tr_selector,
                .type = 11,
                .present = 1
        };
        vmx_set_segment(vcpu, &seg, VCPU_SREG_TR);

        kvm_set_dr(vcpu, 7, 0x400);
        vmcs_write64(GUEST_IA32_DEBUGCTL, 0);
}

/*
 * Emulate an exit from nested guest (L2) to L1, i.e., prepare to run L1
 * and modify vmcs12 to make it see what it would expect to see there if
 * L2 was its real guest. Must only be called when in L2 (is_guest_mode())
 */
static void nested_vmx_vmexit(struct kvm_vcpu *vcpu, u32 exit_reason,
                              u32 exit_intr_info,
                              unsigned long exit_qualification)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);
        struct vmcs12 *vmcs12 = get_vmcs12(vcpu);

        /* trying to cancel vmlaunch/vmresume is a bug */
        WARN_ON_ONCE(vmx->nested.nested_run_pending);

        leave_guest_mode(vcpu);
        prepare_vmcs12(vcpu, vmcs12, exit_reason, exit_intr_info,
                       exit_qualification);

        vmx_load_vmcs01(vcpu);

        if ((exit_reason == EXIT_REASON_EXTERNAL_INTERRUPT)
            && nested_exit_intr_ack_set(vcpu)) {
                int irq = kvm_cpu_get_interrupt(vcpu);
                WARN_ON(irq < 0);
                vmcs12->vm_exit_intr_info = irq |
                        INTR_INFO_VALID_MASK | INTR_TYPE_EXT_INTR;
        }

        trace_kvm_nested_vmexit_inject(vmcs12->vm_exit_reason,
                                       vmcs12->exit_qualification,
                                       vmcs12->idt_vectoring_info_field,
                                       vmcs12->vm_exit_intr_info,
                                       vmcs12->vm_exit_intr_error_code,
                                       KVM_ISA_VMX);

        vm_entry_controls_init(vmx, vmcs_read32(VM_ENTRY_CONTROLS));
        vm_exit_controls_init(vmx, vmcs_read32(VM_EXIT_CONTROLS));
        vmx_segment_cache_clear(vmx);

        /* if no vmcs02 cache requested, remove the one we used */
        if (VMCS02_POOL_SIZE == 0)
                nested_free_vmcs02(vmx, vmx->nested.current_vmptr);

        load_vmcs12_host_state(vcpu, vmcs12);

        /* Update TSC_OFFSET if TSC was changed while L2 ran */
        vmcs_write64(TSC_OFFSET, vmx->nested.vmcs01_tsc_offset);

        /* This is needed for same reason as it was needed in prepare_vmcs02 */
        vmx->host_rsp = 0;

        /* Unpin physical memory we referred to in vmcs02 */
        if (vmx->nested.apic_access_page) {
                nested_release_page(vmx->nested.apic_access_page);
                vmx->nested.apic_access_page = NULL;
        }
        if (vmx->nested.virtual_apic_page) {
                nested_release_page(vmx->nested.virtual_apic_page);
                vmx->nested.virtual_apic_page = NULL;
        }

        /*
         * We are now running in L2, mmu_notifier will force to reload the
         * page's hpa for L2 vmcs. Need to reload it for L1 before entering L1.
         */
        kvm_vcpu_reload_apic_access_page(vcpu);

        /*
         * Exiting from L2 to L1, we're now back to L1 which thinks it just
         * finished a VMLAUNCH or VMRESUME instruction, so we need to set the
         * success or failure flag accordingly.
         */
        if (unlikely(vmx->fail)) {
                vmx->fail = 0;
                nested_vmx_failValid(vcpu, vmcs_read32(VM_INSTRUCTION_ERROR));
        } else
                nested_vmx_succeed(vcpu);
        if (enable_shadow_vmcs)
                vmx->nested.sync_shadow_vmcs = true;

        /* in case we halted in L2 */
        vcpu->arch.mp_state = KVM_MP_STATE_RUNNABLE;
}

/*
 * Forcibly leave nested mode in order to be able to reset the VCPU later on.
 */
static void vmx_leave_nested(struct kvm_vcpu *vcpu)
{
        if (is_guest_mode(vcpu))
                nested_vmx_vmexit(vcpu, -1, 0, 0);
        free_nested(to_vmx(vcpu));
}

/*
 * L1's failure to enter L2 is a subset of a normal exit, as explained in
 * 23.7 "VM-entry failures during or after loading guest state" (this also
 * lists the acceptable exit-reason and exit-qualification parameters).
 * It should only be called before L2 actually succeeded to run, and when
 * vmcs01 is current (it doesn't leave_guest_mode() or switch vmcss).
 */
static void nested_vmx_entry_failure(struct kvm_vcpu *vcpu,
                        struct vmcs12 *vmcs12,
                        u32 reason, unsigned long qualification)
{
        load_vmcs12_host_state(vcpu, vmcs12);
        vmcs12->vm_exit_reason = reason | VMX_EXIT_REASONS_FAILED_VMENTRY;
        vmcs12->exit_qualification = qualification;
        nested_vmx_succeed(vcpu);
        if (enable_shadow_vmcs)
                to_vmx(vcpu)->nested.sync_shadow_vmcs = true;
}

static int vmx_check_intercept(struct kvm_vcpu *vcpu,
                               struct x86_instruction_info *info,
                               enum x86_intercept_stage stage)
{
        return X86EMUL_CONTINUE;
}

static void vmx_sched_in(struct kvm_vcpu *vcpu, int cpu)
{
        if (ple_gap)
                shrink_ple_window(vcpu);
}

static struct kvm_x86_ops vmx_x86_ops = {
        .cpu_has_kvm_support = cpu_has_kvm_support,
        .disabled_by_bios = vmx_disabled_by_bios,
        .hardware_setup = hardware_setup,
        .hardware_unsetup = hardware_unsetup,
        .check_processor_compatibility = vmx_check_processor_compat,
        .hardware_enable = hardware_enable,
        .hardware_disable = hardware_disable,
        .cpu_has_accelerated_tpr = report_flexpriority,

        .vcpu_create = vmx_create_vcpu,
        .vcpu_free = vmx_free_vcpu,
        .vcpu_reset = vmx_vcpu_reset,

        .prepare_guest_switch = vmx_save_host_state,
        .vcpu_load = vmx_vcpu_load,
        .vcpu_put = vmx_vcpu_put,

        .update_db_bp_intercept = update_exception_bitmap,
        .get_msr = vmx_get_msr,
        .set_msr = vmx_set_msr,
        .get_segment_base = vmx_get_segment_base,
        .get_segment = vmx_get_segment,
        .set_segment = vmx_set_segment,
        .get_cpl = vmx_get_cpl,
        .get_cs_db_l_bits = vmx_get_cs_db_l_bits,
        .decache_cr0_guest_bits = vmx_decache_cr0_guest_bits,
        .decache_cr3 = vmx_decache_cr3,
        .decache_cr4_guest_bits = vmx_decache_cr4_guest_bits,
        .set_cr0 = vmx_set_cr0,
        .set_cr3 = vmx_set_cr3,
        .set_cr4 = vmx_set_cr4,
        .set_efer = vmx_set_efer,
        .get_idt = vmx_get_idt,
        .set_idt = vmx_set_idt,
        .get_gdt = vmx_get_gdt,
        .set_gdt = vmx_set_gdt,
        .get_dr6 = vmx_get_dr6,
        .set_dr6 = vmx_set_dr6,
        .set_dr7 = vmx_set_dr7,
        .sync_dirty_debug_regs = vmx_sync_dirty_debug_regs,
        .cache_reg = vmx_cache_reg,
        .get_rflags = vmx_get_rflags,
        .set_rflags = vmx_set_rflags,
        .fpu_deactivate = vmx_fpu_deactivate,

        .tlb_flush = vmx_flush_tlb,

        .run = vmx_vcpu_run,
        .handle_exit = vmx_handle_exit,
        .skip_emulated_instruction = skip_emulated_instruction,
        .set_interrupt_shadow = vmx_set_interrupt_shadow,
        .get_interrupt_shadow = vmx_get_interrupt_shadow,
        .patch_hypercall = vmx_patch_hypercall,
        .set_irq = vmx_inject_irq,
        .set_nmi = vmx_inject_nmi,
        .queue_exception = vmx_queue_exception,
        .cancel_injection = vmx_cancel_injection,
        .interrupt_allowed = vmx_interrupt_allowed,
        .nmi_allowed = vmx_nmi_allowed,
        .get_nmi_mask = vmx_get_nmi_mask,
        .set_nmi_mask = vmx_set_nmi_mask,
        .enable_nmi_window = enable_nmi_window,
        .enable_irq_window = enable_irq_window,
        .update_cr8_intercept = update_cr8_intercept,
        .set_virtual_x2apic_mode = vmx_set_virtual_x2apic_mode,
        .set_apic_access_page_addr = vmx_set_apic_access_page_addr,
        .vm_has_apicv = vmx_vm_has_apicv,
        .load_eoi_exitmap = vmx_load_eoi_exitmap,
        .hwapic_irr_update = vmx_hwapic_irr_update,
        .hwapic_isr_update = vmx_hwapic_isr_update,
        .sync_pir_to_irr = vmx_sync_pir_to_irr,
        .deliver_posted_interrupt = vmx_deliver_posted_interrupt,

        .set_tss_addr = vmx_set_tss_addr,
        .get_tdp_level = get_ept_level,
        .get_mt_mask = vmx_get_mt_mask,

        .get_exit_info = vmx_get_exit_info,

        .get_lpage_level = vmx_get_lpage_level,

        .cpuid_update = vmx_cpuid_update,

        .rdtscp_supported = vmx_rdtscp_supported,
        .invpcid_supported = vmx_invpcid_supported,

        .set_supported_cpuid = vmx_set_supported_cpuid,

        .has_wbinvd_exit = cpu_has_vmx_wbinvd_exit,

        .set_tsc_khz = vmx_set_tsc_khz,
        .read_tsc_offset = vmx_read_tsc_offset,
        .write_tsc_offset = vmx_write_tsc_offset,
        .adjust_tsc_offset = vmx_adjust_tsc_offset,
        .compute_tsc_offset = vmx_compute_tsc_offset,
        .read_l1_tsc = vmx_read_l1_tsc,

        .set_tdp_cr3 = vmx_set_cr3,

        .check_intercept = vmx_check_intercept,
        .handle_external_intr = vmx_handle_external_intr,
        .mpx_supported = vmx_mpx_supported,

        .check_nested_events = vmx_check_nested_events,

        .sched_in = vmx_sched_in,
};

static int __init vmx_init(void)
{
        int r, i, msr;

        rdmsrl_safe(MSR_EFER, &host_efer);

        for (i = 0; i < ARRAY_SIZE(vmx_msr_index); ++i)
                kvm_define_shared_msr(i, vmx_msr_index[i]);

        vmx_io_bitmap_a = (unsigned long *)__get_free_page(GFP_KERNEL);
        if (!vmx_io_bitmap_a)
                return -ENOMEM;

        r = -ENOMEM;

        vmx_io_bitmap_b = (unsigned long *)__get_free_page(GFP_KERNEL);
        if (!vmx_io_bitmap_b)
                goto out;

        vmx_msr_bitmap_legacy = (unsigned long *)__get_free_page(GFP_KERNEL);
        if (!vmx_msr_bitmap_legacy)
                goto out1;

        vmx_msr_bitmap_legacy_x2apic =
                                (unsigned long *)__get_free_page(GFP_KERNEL);
        if (!vmx_msr_bitmap_legacy_x2apic)
                goto out2;

        vmx_msr_bitmap_longmode = (unsigned long *)__get_free_page(GFP_KERNEL);
        if (!vmx_msr_bitmap_longmode)
                goto out3;

        vmx_msr_bitmap_longmode_x2apic =
                                (unsigned long *)__get_free_page(GFP_KERNEL);
        if (!vmx_msr_bitmap_longmode_x2apic)
                goto out4;
        vmx_vmread_bitmap = (unsigned long *)__get_free_page(GFP_KERNEL);
        if (!vmx_vmread_bitmap)
                goto out5;

        vmx_vmwrite_bitmap = (unsigned long *)__get_free_page(GFP_KERNEL);
        if (!vmx_vmwrite_bitmap)
                goto out6;

        memset(vmx_vmread_bitmap, 0xff, PAGE_SIZE);
        memset(vmx_vmwrite_bitmap, 0xff, PAGE_SIZE);

        /*
         * Allow direct access to the PC debug port (it is often used for I/O
         * delays, but the vmexits simply slow things down).
         */
        memset(vmx_io_bitmap_a, 0xff, PAGE_SIZE);
        clear_bit(0x80, vmx_io_bitmap_a);

        memset(vmx_io_bitmap_b, 0xff, PAGE_SIZE);

        memset(vmx_msr_bitmap_legacy, 0xff, PAGE_SIZE);
        memset(vmx_msr_bitmap_longmode, 0xff, PAGE_SIZE);

        set_bit(0, vmx_vpid_bitmap); /* 0 is reserved for host */

        r = kvm_init(&vmx_x86_ops, sizeof(struct vcpu_vmx),
                     __alignof__(struct vcpu_vmx), THIS_MODULE);
        if (r)
                goto out7;

#ifdef CONFIG_KEXEC
        rcu_assign_pointer(crash_vmclear_loaded_vmcss,
                           crash_vmclear_local_loaded_vmcss);
#endif

        vmx_disable_intercept_for_msr(MSR_FS_BASE, false);
        vmx_disable_intercept_for_msr(MSR_GS_BASE, false);
        vmx_disable_intercept_for_msr(MSR_KERNEL_GS_BASE, true);
        vmx_disable_intercept_for_msr(MSR_IA32_SYSENTER_CS, false);
        vmx_disable_intercept_for_msr(MSR_IA32_SYSENTER_ESP, false);
        vmx_disable_intercept_for_msr(MSR_IA32_SYSENTER_EIP, false);
        vmx_disable_intercept_for_msr(MSR_IA32_BNDCFGS, true);

        memcpy(vmx_msr_bitmap_legacy_x2apic,
                        vmx_msr_bitmap_legacy, PAGE_SIZE);
        memcpy(vmx_msr_bitmap_longmode_x2apic,
                        vmx_msr_bitmap_longmode, PAGE_SIZE);

        if (enable_apicv) {
                for (msr = 0x800; msr <= 0x8ff; msr++)
                        vmx_disable_intercept_msr_read_x2apic(msr);

                /* According SDM, in x2apic mode, the whole id reg is used.
                 * But in KVM, it only use the highest eight bits. Need to
                 * intercept it */
                vmx_enable_intercept_msr_read_x2apic(0x802);
                /* TMCCT */
                vmx_enable_intercept_msr_read_x2apic(0x839);
                /* TPR */
                vmx_disable_intercept_msr_write_x2apic(0x808);
                /* EOI */
                vmx_disable_intercept_msr_write_x2apic(0x80b);
                /* SELF-IPI */
                vmx_disable_intercept_msr_write_x2apic(0x83f);
        }

        if (enable_ept) {
                kvm_mmu_set_mask_ptes(0ull,
                        (enable_ept_ad_bits) ? VMX_EPT_ACCESS_BIT : 0ull,
                        (enable_ept_ad_bits) ? VMX_EPT_DIRTY_BIT : 0ull,
                        0ull, VMX_EPT_EXECUTABLE_MASK);
                ept_set_mmio_spte_mask();
                kvm_enable_tdp();
        } else
                kvm_disable_tdp();

        update_ple_window_actual_max();

        return 0;

out7:
        free_page((unsigned long)vmx_vmwrite_bitmap);
out6:
        free_page((unsigned long)vmx_vmread_bitmap);
out5:
        free_page((unsigned long)vmx_msr_bitmap_longmode_x2apic);
out4:
        free_page((unsigned long)vmx_msr_bitmap_longmode);
out3:
        free_page((unsigned long)vmx_msr_bitmap_legacy_x2apic);
out2:
        free_page((unsigned long)vmx_msr_bitmap_legacy);
out1:
        free_page((unsigned long)vmx_io_bitmap_b);
out:
        free_page((unsigned long)vmx_io_bitmap_a);
        return r;
}

static void __exit vmx_exit(void)
{
        free_page((unsigned long)vmx_msr_bitmap_legacy_x2apic);
        free_page((unsigned long)vmx_msr_bitmap_longmode_x2apic);
        free_page((unsigned long)vmx_msr_bitmap_legacy);
        free_page((unsigned long)vmx_msr_bitmap_longmode);
        free_page((unsigned long)vmx_io_bitmap_b);
        free_page((unsigned long)vmx_io_bitmap_a);
        free_page((unsigned long)vmx_vmwrite_bitmap);
        free_page((unsigned long)vmx_vmread_bitmap);

#ifdef CONFIG_KEXEC
        RCU_INIT_POINTER(crash_vmclear_loaded_vmcss, NULL);
        synchronize_rcu();
#endif

        kvm_exit();
}

module_init(vmx_init)
module_exit(vmx_exit)