3 files changed, 14 insertions, 8 deletions

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index c2a01d0513f5..9efc446b5ac6 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -398,6 +398,7 @@ struct kvm_arch{
 
         unsigned long irq_sources_bitmap;
         unsigned long irq_states[KVM_IOAPIC_NUM_PINS];
+        u64 vm_init_tsc;
 };
 
 struct kvm_vm_stat {
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index cee81c9a6653..3312047664a4 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -865,11 +865,8 @@ static u64 guest_read_tsc(void)
  * writes 'guest_tsc' into guest's timestamp counter "register"
  * guest_tsc = host_tsc + tsc_offset ==> tsc_offset = guest_tsc - host_tsc
  */
-static void guest_write_tsc(u64 guest_tsc)
+static void guest_write_tsc(u64 guest_tsc, u64 host_tsc)
 {
-        u64 host_tsc;
-
-        rdtscll(host_tsc);
         vmcs_write64(TSC_OFFSET, guest_tsc - host_tsc);
 }
 
@@ -934,6 +931,7 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 data)
 {
         struct vcpu_vmx *vmx = to_vmx(vcpu);
         struct kvm_msr_entry *msr;
+        u64 host_tsc;
         int ret = 0;
 
         switch (msr_index) {
@@ -959,7 +957,8 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 data)
                 vmcs_writel(GUEST_SYSENTER_ESP, data);
                 break;
         case MSR_IA32_TIME_STAMP_COUNTER:
-                guest_write_tsc(data);
+                rdtscll(host_tsc);
+                guest_write_tsc(data, host_tsc);
                 break;
         case MSR_P6_PERFCTR0:
         case MSR_P6_PERFCTR1:
@@ -2109,7 +2108,7 @@ static int vmx_vcpu_setup(struct vcpu_vmx *vmx)
 {
         u32 host_sysenter_cs, msr_low, msr_high;
         u32 junk;
-        u64 host_pat;
+        u64 host_pat, tsc_this, tsc_base;
         unsigned long a;
         struct descriptor_table dt;
         int i;
@@ -2237,6 +2236,12 @@ static int vmx_vcpu_setup(struct vcpu_vmx *vmx)
         vmcs_writel(CR0_GUEST_HOST_MASK, ~0UL);
         vmcs_writel(CR4_GUEST_HOST_MASK, KVM_GUEST_CR4_MASK);
 
+        tsc_base = vmx->vcpu.kvm->arch.vm_init_tsc;
+        rdtscll(tsc_this);
+        if (tsc_this < vmx->vcpu.kvm->arch.vm_init_tsc)
+                tsc_base = tsc_this;
+
+        guest_write_tsc(0, tsc_base);
 
         return 0;
 }
@@ -2328,8 +2333,6 @@ static int vmx_vcpu_reset(struct kvm_vcpu *vcpu)
         vmcs_write32(GUEST_INTERRUPTIBILITY_INFO, 0);
         vmcs_write32(GUEST_PENDING_DBG_EXCEPTIONS, 0);
 
-        guest_write_tsc(0);
-
         /* Special registers */
         vmcs_write64(GUEST_IA32_DEBUGCTL, 0);
 
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 873602b5edfd..3b2acfd72d7f 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -4170,6 +4170,8 @@ struct  kvm *kvm_arch_create_vm(void)
         /* Reserve bit 0 of irq_sources_bitmap for userspace irq source */
         set_bit(KVM_USERSPACE_IRQ_SOURCE_ID, &kvm->arch.irq_sources_bitmap);
 
+        rdtscll(kvm->arch.vm_init_tsc);
+
         return kvm;
 }