KVM: x86: disallow KVM_{SET,GET}_LAPIC without allocated in-kernel lapic
[deliverable/linux.git] / arch / x86 / kvm / x86.c
index 13f30aac460b8a39f8cf10b1c17cfefead7c70df..cd6fe0a5797fb094e4e805b275d10f1869056e00 100644 (file)
@@ -37,6 +37,7 @@
 #include <linux/iommu.h>
 #include <linux/intel-iommu.h>
 #include <linux/cpufreq.h>
+#include <linux/user-return-notifier.h>
 #include <trace/events/kvm.h>
 #undef TRACE_INCLUDE_FILE
 #define CREATE_TRACE_POINTS
@@ -87,6 +88,25 @@ EXPORT_SYMBOL_GPL(kvm_x86_ops);
 int ignore_msrs = 0;
 module_param_named(ignore_msrs, ignore_msrs, bool, S_IRUGO | S_IWUSR);
 
+#define KVM_NR_SHARED_MSRS 16
+
+struct kvm_shared_msrs_global {
+       int nr;
+       struct kvm_shared_msr {
+               u32 msr;
+               u64 value;
+       } msrs[KVM_NR_SHARED_MSRS];
+};
+
+struct kvm_shared_msrs {
+       struct user_return_notifier urn;
+       bool registered;
+       u64 current_value[KVM_NR_SHARED_MSRS];
+};
+
+static struct kvm_shared_msrs_global __read_mostly shared_msrs_global;
+static DEFINE_PER_CPU(struct kvm_shared_msrs, shared_msrs);
+
 struct kvm_stats_debugfs_item debugfs_entries[] = {
        { "pf_fixed", VCPU_STAT(pf_fixed) },
        { "pf_guest", VCPU_STAT(pf_guest) },
@@ -123,6 +143,64 @@ struct kvm_stats_debugfs_item debugfs_entries[] = {
        { NULL }
 };
 
+static void kvm_on_user_return(struct user_return_notifier *urn)
+{
+       unsigned slot;
+       struct kvm_shared_msr *global;
+       struct kvm_shared_msrs *locals
+               = container_of(urn, struct kvm_shared_msrs, urn);
+
+       for (slot = 0; slot < shared_msrs_global.nr; ++slot) {
+               global = &shared_msrs_global.msrs[slot];
+               if (global->value != locals->current_value[slot]) {
+                       wrmsrl(global->msr, global->value);
+                       locals->current_value[slot] = global->value;
+               }
+       }
+       locals->registered = false;
+       user_return_notifier_unregister(urn);
+}
+
+void kvm_define_shared_msr(unsigned slot, u32 msr)
+{
+       int cpu;
+       u64 value;
+
+       if (slot >= shared_msrs_global.nr)
+               shared_msrs_global.nr = slot + 1;
+       shared_msrs_global.msrs[slot].msr = msr;
+       rdmsrl_safe(msr, &value);
+       shared_msrs_global.msrs[slot].value = value;
+       for_each_online_cpu(cpu)
+               per_cpu(shared_msrs, cpu).current_value[slot] = value;
+}
+EXPORT_SYMBOL_GPL(kvm_define_shared_msr);
+
+static void kvm_shared_msr_cpu_online(void)
+{
+       unsigned i;
+       struct kvm_shared_msrs *locals = &__get_cpu_var(shared_msrs);
+
+       for (i = 0; i < shared_msrs_global.nr; ++i)
+               locals->current_value[i] = shared_msrs_global.msrs[i].value;
+}
+
+void kvm_set_shared_msr(unsigned slot, u64 value)
+{
+       struct kvm_shared_msrs *smsr = &__get_cpu_var(shared_msrs);
+
+       if (value == smsr->current_value[slot])
+               return;
+       smsr->current_value[slot] = value;
+       wrmsrl(shared_msrs_global.msrs[slot].msr, value);
+       if (!smsr->registered) {
+               smsr->urn.on_user_return = kvm_on_user_return;
+               user_return_notifier_register(&smsr->urn);
+               smsr->registered = true;
+       }
+}
+EXPORT_SYMBOL_GPL(kvm_set_shared_msr);
+
 unsigned long segment_base(u16 selector)
 {
        struct descriptor_table gdt;
@@ -680,7 +758,8 @@ static void kvm_write_guest_time(struct kvm_vcpu *v)
        /* With all the info we got, fill in the values */
 
        vcpu->hv_clock.system_time = ts.tv_nsec +
-                                    (NSEC_PER_SEC * (u64)ts.tv_sec);
+                                    (NSEC_PER_SEC * (u64)ts.tv_sec) + v->kvm->arch.kvmclock_offset;
+
        /*
         * The interface expects us to write an even number signaling that the
         * update is finished. Since the guest won't see the intermediate
@@ -1262,6 +1341,7 @@ int kvm_dev_ioctl_check_extension(long ext)
        case KVM_CAP_PIT_STATE2:
        case KVM_CAP_SET_IDENTITY_MAP_ADDR:
        case KVM_CAP_XEN_HVM:
+       case KVM_CAP_ADJUST_CLOCK:
                r = 1;
                break;
        case KVM_CAP_COALESCED_MMIO:
@@ -1813,6 +1893,9 @@ long kvm_arch_vcpu_ioctl(struct file *filp,
 
        switch (ioctl) {
        case KVM_GET_LAPIC: {
+               r = -EINVAL;
+               if (!vcpu->arch.apic)
+                       goto out;
                lapic = kzalloc(sizeof(struct kvm_lapic_state), GFP_KERNEL);
 
                r = -ENOMEM;
@@ -1828,6 +1911,9 @@ long kvm_arch_vcpu_ioctl(struct file *filp,
                break;
        }
        case KVM_SET_LAPIC: {
+               r = -EINVAL;
+               if (!vcpu->arch.apic)
+                       goto out;
                lapic = kmalloc(sizeof(struct kvm_lapic_state), GFP_KERNEL);
                r = -ENOMEM;
                if (!lapic)
@@ -2282,25 +2368,39 @@ long kvm_arch_vm_ioctl(struct file *filp,
                if (r)
                        goto out;
                break;
-       case KVM_CREATE_IRQCHIP:
+       case KVM_CREATE_IRQCHIP: {
+               struct kvm_pic *vpic;
+
+               mutex_lock(&kvm->lock);
+               r = -EEXIST;
+               if (kvm->arch.vpic)
+                       goto create_irqchip_unlock;
                r = -ENOMEM;
-               kvm->arch.vpic = kvm_create_pic(kvm);
-               if (kvm->arch.vpic) {
+               vpic = kvm_create_pic(kvm);
+               if (vpic) {
                        r = kvm_ioapic_init(kvm);
                        if (r) {
-                               kfree(kvm->arch.vpic);
-                               kvm->arch.vpic = NULL;
-                               goto out;
+                               kfree(vpic);
+                               goto create_irqchip_unlock;
                        }
                } else
-                       goto out;
+                       goto create_irqchip_unlock;
+               smp_wmb();
+               kvm->arch.vpic = vpic;
+               smp_wmb();
                r = kvm_setup_default_irq_routing(kvm);
                if (r) {
+                       mutex_lock(&kvm->irq_lock);
                        kfree(kvm->arch.vpic);
                        kfree(kvm->arch.vioapic);
-                       goto out;
+                       kvm->arch.vpic = NULL;
+                       kvm->arch.vioapic = NULL;
+                       mutex_unlock(&kvm->irq_lock);
                }
+       create_irqchip_unlock:
+               mutex_unlock(&kvm->lock);
                break;
+       }
        case KVM_CREATE_PIT:
                u.pit_config.flags = KVM_PIT_SPEAKER_DUMMY;
                goto create_pit;
@@ -2468,6 +2568,44 @@ long kvm_arch_vm_ioctl(struct file *filp,
                r = 0;
                break;
        }
+       case KVM_SET_CLOCK: {
+               struct timespec now;
+               struct kvm_clock_data user_ns;
+               u64 now_ns;
+               s64 delta;
+
+               r = -EFAULT;
+               if (copy_from_user(&user_ns, argp, sizeof(user_ns)))
+                       goto out;
+
+               r = -EINVAL;
+               if (user_ns.flags)
+                       goto out;
+
+               r = 0;
+               ktime_get_ts(&now);
+               now_ns = timespec_to_ns(&now);
+               delta = user_ns.clock - now_ns;
+               kvm->arch.kvmclock_offset = delta;
+               break;
+       }
+       case KVM_GET_CLOCK: {
+               struct timespec now;
+               struct kvm_clock_data user_ns;
+               u64 now_ns;
+
+               ktime_get_ts(&now);
+               now_ns = timespec_to_ns(&now);
+               user_ns.clock = kvm->arch.kvmclock_offset + now_ns;
+               user_ns.flags = 0;
+
+               r = -EFAULT;
+               if (copy_to_user(argp, &user_ns, sizeof(user_ns)))
+                       goto out;
+               r = 0;
+               break;
+       }
+
        default:
                ;
        }
@@ -4407,11 +4545,6 @@ int kvm_task_switch(struct kvm_vcpu *vcpu, u16 tss_selector, int reason)
                kvm_set_rflags(vcpu, eflags & ~X86_EFLAGS_NT);
        }
 
-       /* set back link to prev task only if NT bit is set in eflags
-          note that old_tss_sel is not used afetr this point */
-       if (reason != TASK_SWITCH_CALL && reason != TASK_SWITCH_GATE)
-               old_tss_sel = 0xffff;
-
        /* set back link to prev task only if NT bit is set in eflags
           note that old_tss_sel is not used afetr this point */
        if (reason != TASK_SWITCH_CALL && reason != TASK_SWITCH_GATE)
@@ -4478,8 +4611,10 @@ int kvm_arch_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu,
 
        mmu_reset_needed |= vcpu->arch.cr4 != sregs->cr4;
        kvm_x86_ops->set_cr4(vcpu, sregs->cr4);
-       if (!is_long_mode(vcpu) && is_pae(vcpu))
+       if (!is_long_mode(vcpu) && is_pae(vcpu)) {
                load_pdptrs(vcpu, vcpu->arch.cr3);
+               mmu_reset_needed = 1;
+       }
 
        if (mmu_reset_needed)
                kvm_mmu_reset_context(vcpu);
@@ -4775,6 +4910,9 @@ int kvm_arch_hardware_enable(void *garbage)
                int cpu = raw_smp_processor_id();
                per_cpu(cpu_tsc_khz, cpu) = 0;
        }
+
+       kvm_shared_msr_cpu_online();
+
        return kvm_x86_ops->hardware_enable(garbage);
 }
 
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