1 files changed, 72 insertions, 2 deletions

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 0b803f04bde..c96cdc09248 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -808,12 +808,12 @@ EXPORT_SYMBOL_GPL(kvm_get_dr);
  * kvm-specific. Those are put in the beginning of the list.
  */
 
-#define KVM_SAVE_MSRS_BEGIN	8
+#define KVM_SAVE_MSRS_BEGIN	9
 static u32 msrs_to_save[] = {
 	MSR_KVM_SYSTEM_TIME, MSR_KVM_WALL_CLOCK,
 	MSR_KVM_SYSTEM_TIME_NEW, MSR_KVM_WALL_CLOCK_NEW,
 	HV_X64_MSR_GUEST_OS_ID, HV_X64_MSR_HYPERCALL,
-	HV_X64_MSR_APIC_ASSIST_PAGE, MSR_KVM_ASYNC_PF_EN,
+	HV_X64_MSR_APIC_ASSIST_PAGE, MSR_KVM_ASYNC_PF_EN, MSR_KVM_STEAL_TIME,
 	MSR_IA32_SYSENTER_CS, MSR_IA32_SYSENTER_ESP, MSR_IA32_SYSENTER_EIP,
 	MSR_STAR,
 #ifdef CONFIG_X86_64
@@ -1488,6 +1488,35 @@ static void kvmclock_reset(struct kvm_vcpu *vcpu)
 	}
 }
 
+static void accumulate_steal_time(struct kvm_vcpu *vcpu)
+{
+	u64 delta;
+
+	if (!(vcpu->arch.st.msr_val & KVM_MSR_ENABLED))
+		return;
+
+	delta = current->sched_info.run_delay - vcpu->arch.st.last_steal;
+	vcpu->arch.st.last_steal = current->sched_info.run_delay;
+	vcpu->arch.st.accum_steal = delta;
+}
+
+static void record_steal_time(struct kvm_vcpu *vcpu)
+{
+	if (!(vcpu->arch.st.msr_val & KVM_MSR_ENABLED))
+		return;
+
+	if (unlikely(kvm_read_guest_cached(vcpu->kvm, &vcpu->arch.st.stime,
+		&vcpu->arch.st.steal, sizeof(struct kvm_steal_time))))
+		return;
+
+	vcpu->arch.st.steal.steal += vcpu->arch.st.accum_steal;
+	vcpu->arch.st.steal.version += 2;
+	vcpu->arch.st.accum_steal = 0;
+
+	kvm_write_guest_cached(vcpu->kvm, &vcpu->arch.st.stime,
+		&vcpu->arch.st.steal, sizeof(struct kvm_steal_time));
+}
+
 int kvm_set_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 data)
 {
 	switch (msr) {
@@ -1570,6 +1599,33 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 data)
 		if (kvm_pv_enable_async_pf(vcpu, data))
 			return 1;
 		break;
+	case MSR_KVM_STEAL_TIME:
+
+		if (unlikely(!sched_info_on()))
+			return 1;
+
+		if (data & KVM_STEAL_RESERVED_MASK)
+			return 1;
+
+		if (kvm_gfn_to_hva_cache_init(vcpu->kvm, &vcpu->arch.st.stime,
+							data & KVM_STEAL_VALID_BITS))
+			return 1;
+
+		vcpu->arch.st.msr_val = data;
+
+		if (!(data & KVM_MSR_ENABLED))
+			break;
+
+		vcpu->arch.st.last_steal = current->sched_info.run_delay;
+
+		preempt_disable();
+		accumulate_steal_time(vcpu);
+		preempt_enable();
+
+		kvm_make_request(KVM_REQ_STEAL_UPDATE, vcpu);
+
+		break;
+
 	case MSR_IA32_MCG_CTL:
 	case MSR_IA32_MCG_STATUS:
 	case MSR_IA32_MC0_CTL ... MSR_IA32_MC0_CTL + 4 * KVM_MAX_MCE_BANKS - 1:
@@ -1855,6 +1911,9 @@ int kvm_get_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata)
 	case MSR_KVM_ASYNC_PF_EN:
 		data = vcpu->arch.apf.msr_val;
 		break;
+	case MSR_KVM_STEAL_TIME:
+		data = vcpu->arch.st.msr_val;
+		break;
 	case MSR_IA32_P5_MC_ADDR:
 	case MSR_IA32_P5_MC_TYPE:
 	case MSR_IA32_MCG_CAP:
@@ -2166,6 +2225,9 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
 			kvm_migrate_timers(vcpu);
 		vcpu->cpu = cpu;
 	}
+
+	accumulate_steal_time(vcpu);
+	kvm_make_request(KVM_REQ_STEAL_UPDATE, vcpu);
 }
 
 void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
@@ -2487,6 +2549,10 @@ static void do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
 			     (1 << KVM_FEATURE_CLOCKSOURCE2) |
 			     (1 << KVM_FEATURE_ASYNC_PF) |
 			     (1 << KVM_FEATURE_CLOCKSOURCE_STABLE_BIT);
+
+		if (sched_info_on())
+			entry->eax |= (1 << KVM_FEATURE_STEAL_TIME);
+
 		entry->ebx = 0;
 		entry->ecx = 0;
 		entry->edx = 0;
@@ -5470,6 +5536,9 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu)
 			r = 1;
 			goto out;
 		}
+		if (kvm_check_request(KVM_REQ_STEAL_UPDATE, vcpu))
+			record_steal_time(vcpu);
+
 	}
 
 	r = kvm_mmu_reload(vcpu);
@@ -6206,6 +6275,7 @@ int kvm_arch_vcpu_reset(struct kvm_vcpu *vcpu)
 
 	kvm_make_request(KVM_REQ_EVENT, vcpu);
 	vcpu->arch.apf.msr_val = 0;
+	vcpu->arch.st.msr_val = 0;
 
 	kvmclock_reset(vcpu);