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-rw-r--r--drivers/kvm/kvm.h1
-rw-r--r--drivers/kvm/svm.c21
2 files changed, 18 insertions, 4 deletions
diff --git a/drivers/kvm/kvm.h b/drivers/kvm/kvm.h
index f5e343c..6d0bd7a 100644
--- a/drivers/kvm/kvm.h
+++ b/drivers/kvm/kvm.h
@@ -244,6 +244,7 @@ struct kvm_vcpu {
struct mutex mutex;
int cpu;
int launched;
+ u64 host_tsc;
struct kvm_run *run;
int interrupt_window_open;
unsigned long irq_summary; /* bit vector: 1 per word in irq_pending */
diff --git a/drivers/kvm/svm.c b/drivers/kvm/svm.c
index 0542d33..ca2642f 100644
--- a/drivers/kvm/svm.c
+++ b/drivers/kvm/svm.c
@@ -459,7 +459,6 @@ static void init_vmcb(struct vmcb *vmcb)
{
struct vmcb_control_area *control = &vmcb->control;
struct vmcb_save_area *save = &vmcb->save;
- u64 tsc;
control->intercept_cr_read = INTERCEPT_CR0_MASK |
INTERCEPT_CR3_MASK |
@@ -517,8 +516,7 @@ static void init_vmcb(struct vmcb *vmcb)
control->iopm_base_pa = iopm_base;
control->msrpm_base_pa = msrpm_base;
- rdtscll(tsc);
- control->tsc_offset = -tsc;
+ control->tsc_offset = 0;
control->int_ctl = V_INTR_MASKING_MASK;
init_seg(&save->es);
@@ -606,11 +604,26 @@ static void svm_free_vcpu(struct kvm_vcpu *vcpu)
static void svm_vcpu_load(struct kvm_vcpu *vcpu)
{
- get_cpu();
+ int cpu;
+
+ cpu = get_cpu();
+ if (unlikely(cpu != vcpu->cpu)) {
+ u64 tsc_this, delta;
+
+ /*
+ * Make sure that the guest sees a monotonically
+ * increasing TSC.
+ */
+ rdtscll(tsc_this);
+ delta = vcpu->host_tsc - tsc_this;
+ vcpu->svm->vmcb->control.tsc_offset += delta;
+ vcpu->cpu = cpu;
+ }
}
static void svm_vcpu_put(struct kvm_vcpu *vcpu)
{
+ rdtscll(vcpu->host_tsc);
put_cpu();
}
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