arch/x86/include/asm/kvm_para.h

   1 #ifndef _ASM_X86_KVM_PARA_H
   2 #define _ASM_X86_KVM_PARA_H
   3
   4 #include <asm/processor.h>
   5 #include <uapi/asm/kvm_para.h>
   6
   7 extern void kvmclock_init(void);
   8 extern int kvm_register_clock(char *txt);
   9
  10 #ifdef CONFIG_KVM_GUEST
  11 bool kvm_check_and_clear_guest_paused(void);
  12 #else
  13 static inline bool kvm_check_and_clear_guest_paused(void)
  14 {
  15         return false;
  16 }
  17 #endif /* CONFIG_KVM_GUEST */
  18
  19 /* This instruction is vmcall.  On non-VT architectures, it will generate a
  20  * trap that we will then rewrite to the appropriate instruction.
  21  */
  22 #define KVM_HYPERCALL ".byte 0x0f,0x01,0xc1"
  23
  24 /* For KVM hypercalls, a three-byte sequence of either the vmcall or the vmmcall
  25  * instruction.  The hypervisor may replace it with something else but only the
  26  * instructions are guaranteed to be supported.
  27  *
  28  * Up to four arguments may be passed in rbx, rcx, rdx, and rsi respectively.
  29  * The hypercall number should be placed in rax and the return value will be
  30  * placed in rax.  No other registers will be clobbered unless explicitly
  31  * noted by the particular hypercall.
  32  */
  33
  34 static inline long kvm_hypercall0(unsigned int nr)
  35 {
  36         long ret;
  37         asm volatile(KVM_HYPERCALL
  38                      : "=a"(ret)
  39                      : "a"(nr)
  40                      : "memory");
  41         return ret;
  42 }
  43
  44 static inline long kvm_hypercall1(unsigned int nr, unsigned long p1)
  45 {
  46         long ret;
  47         asm volatile(KVM_HYPERCALL
  48                      : "=a"(ret)
  49                      : "a"(nr), "b"(p1)
  50                      : "memory");
  51         return ret;
  52 }
  53
  54 static inline long kvm_hypercall2(unsigned int nr, unsigned long p1,
  55                                   unsigned long p2)
  56 {
  57         long ret;
  58         asm volatile(KVM_HYPERCALL
  59                      : "=a"(ret)
  60                      : "a"(nr), "b"(p1), "c"(p2)
  61                      : "memory");
  62         return ret;
  63 }
  64
  65 static inline long kvm_hypercall3(unsigned int nr, unsigned long p1,
  66                                   unsigned long p2, unsigned long p3)
  67 {
  68         long ret;
  69         asm volatile(KVM_HYPERCALL
  70                      : "=a"(ret)
  71                      : "a"(nr), "b"(p1), "c"(p2), "d"(p3)
  72                      : "memory");
  73         return ret;
  74 }
  75
  76 static inline long kvm_hypercall4(unsigned int nr, unsigned long p1,
  77                                   unsigned long p2, unsigned long p3,
  78                                   unsigned long p4)
  79 {
  80         long ret;
  81         asm volatile(KVM_HYPERCALL
  82                      : "=a"(ret)
  83                      : "a"(nr), "b"(p1), "c"(p2), "d"(p3), "S"(p4)
  84                      : "memory");
  85         return ret;
  86 }
  87
  88 static inline bool kvm_para_available(void)
  89 {
  90         unsigned int eax, ebx, ecx, edx;
  91         char signature[13];
  92
  93         if (boot_cpu_data.cpuid_level < 0)
  94                 return false;   /* So we don't blow up on old processors */
  95
  96         if (cpu_has_hypervisor) {
  97                 cpuid(KVM_CPUID_SIGNATURE, &eax, &ebx, &ecx, &edx);
  98                 memcpy(signature + 0, &ebx, 4);
  99                 memcpy(signature + 4, &ecx, 4);
 100                 memcpy(signature + 8, &edx, 4);
 101                 signature[12] = 0;
 102
 103                 if (strcmp(signature, "KVMKVMKVM") == 0)
 104                         return true;
 105         }
 106
 107         return false;
 108 }
 109
 110 static inline unsigned int kvm_arch_para_features(void)
 111 {
 112         return cpuid_eax(KVM_CPUID_FEATURES);
 113 }
 114
 115 #ifdef CONFIG_KVM_GUEST
 116 void __init kvm_guest_init(void);
 117 void kvm_async_pf_task_wait(u32 token);
 118 void kvm_async_pf_task_wake(u32 token);
 119 u32 kvm_read_and_reset_pf_reason(void);
 120 extern void kvm_disable_steal_time(void);
 121 #else
 122 #define kvm_guest_init() do { } while (0)
 123 #define kvm_async_pf_task_wait(T) do {} while(0)
 124 #define kvm_async_pf_task_wake(T) do {} while(0)
 125 static inline u32 kvm_read_and_reset_pf_reason(void)
 126 {
 127         return 0;
 128 }
 129
 130 static inline void kvm_disable_steal_time(void)
 131 {
 132         return;
 133 }
 134 #endif
 135
 136 #endif /* _ASM_X86_KVM_PARA_H */