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Diffstat (limited to 'arch/x86/kvm/vmx.c')
-rw-r--r--arch/x86/kvm/vmx.c14
1 files changed, 8 insertions, 6 deletions
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 533a327372c8..4655d6dd6759 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -11427,16 +11427,18 @@ static void vmx_start_preemption_timer(struct kvm_vcpu *vcpu)
u64 preemption_timeout = get_vmcs12(vcpu)->vmx_preemption_timer_value;
struct vcpu_vmx *vmx = to_vmx(vcpu);
- if (vcpu->arch.virtual_tsc_khz == 0)
- return;
-
- /* Make sure short timeouts reliably trigger an immediate vmexit.
- * hrtimer_start does not guarantee this. */
- if (preemption_timeout <= 1) {
+ /*
+ * A timer value of zero is architecturally guaranteed to cause
+ * a VMExit prior to executing any instructions in the guest.
+ */
+ if (preemption_timeout == 0) {
vmx_preemption_timer_fn(&vmx->nested.preemption_timer);
return;
}
+ if (vcpu->arch.virtual_tsc_khz == 0)
+ return;
+
preemption_timeout <<= VMX_MISC_EMULATED_PREEMPTION_TIMER_RATE;
preemption_timeout *= 1000000;
do_div(preemption_timeout, vcpu->arch.virtual_tsc_khz);