4 files changed, 86 insertions, 2 deletions

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index da6bbee878ca..59086a77ff13 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -389,6 +389,15 @@ struct kvm_vcpu_arch {
         unsigned int hw_tsc_khz;
         unsigned int time_offset;
         struct page *time_page;
+
+        struct {
+                u64 msr_val;
+                u64 last_steal;
+                u64 accum_steal;
+                struct gfn_to_hva_cache stime;
+                struct kvm_steal_time steal;
+        } st;
+
         u64 last_guest_tsc;
         u64 last_kernel_ns;
         u64 last_tsc_nsec;
diff --git a/arch/x86/include/asm/kvm_para.h b/arch/x86/include/asm/kvm_para.h
index 65f8bb9279e0..c484ba8e05ea 100644
--- a/arch/x86/include/asm/kvm_para.h
+++ b/arch/x86/include/asm/kvm_para.h
@@ -45,6 +45,10 @@ struct kvm_steal_time {
         __u32 pad[12];
 };
 
+#define KVM_STEAL_ALIGNMENT_BITS 5
+#define KVM_STEAL_VALID_BITS ((-1ULL << (KVM_STEAL_ALIGNMENT_BITS + 1)))
+#define KVM_STEAL_RESERVED_MASK (((1 << KVM_STEAL_ALIGNMENT_BITS) - 1 ) << 1)
+
 #define KVM_MAX_MMU_OP_BATCH           32
 
 #define KVM_ASYNC_PF_ENABLED                    (1 << 0)
diff --git a/arch/x86/kvm/Kconfig b/arch/x86/kvm/Kconfig
index 50f63648ce1b..99c3f0589faa 100644
--- a/arch/x86/kvm/Kconfig
+++ b/arch/x86/kvm/Kconfig
@@ -31,6 +31,7 @@ config KVM
         select KVM_ASYNC_PF
         select USER_RETURN_NOTIFIER
         select KVM_MMIO
+        select TASK_DELAY_ACCT
         ---help---
           Support hosting fully virtualized guest machines using hardware
           virtualization extensions.  You will need a fairly recent
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 0b803f04bde7..c96cdc092484 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);