Re: [PATCH 1/2 v5] KVM: nVMX: Fix VMX preemption timer migration

[Paolo Bonzini <pbonzini@xxxxxxxxxx>]

On 26/05/20 23:51, Makarand Sonare wrote:
> +
> +	u64 l1_scaled_tsc = kvm_read_l1_tsc(vcpu, rdtsc()) >>
> +			    VMX_MISC_EMULATED_PREEMPTION_TIMER_RATE;
> +
> +	if (!vmx->nested.has_preemption_timer_deadline) {
> +		timer_value = vmcs12->vmx_preemption_timer_value;
> +		vmx->nested.preemption_timer_deadline = timer_value +
> +							l1_scaled_tsc;
> +		vmx->nested.has_preemption_timer_deadline = true;
> +	} else if (l1_scaled_tsc < vmx->nested.preemption_timer_deadline)
> +		timer_value = vmx->nested.preemption_timer_deadline -
> +			      l1_scaled_tsc;
> +	return timer_value;

Queued, thanks!  Just a tiny change that I squashed here:

diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index da87bb8670bb..9c74a732b08d 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -2091,20 +2091,16 @@ static u64 vmx_calc_preemption_timer_value(struct kvm_vcpu *vcpu)
 {
 	struct vcpu_vmx *vmx = to_vmx(vcpu);
 	struct vmcs12 *vmcs12 = get_vmcs12(vcpu);
-	u64 timer_value = 0;
 
 	u64 l1_scaled_tsc = kvm_read_l1_tsc(vcpu, rdtsc()) >>
 			    VMX_MISC_EMULATED_PREEMPTION_TIMER_RATE;
 
 	if (!vmx->nested.has_preemption_timer_deadline) {
-		timer_value = vmcs12->vmx_preemption_timer_value;
-		vmx->nested.preemption_timer_deadline = timer_value +
-							l1_scaled_tsc;
+		vmx->nested.preemption_timer_deadline =
+			vmcs12->vmx_preemption_timer_value + l1_scaled_tsc;
 		vmx->nested.has_preemption_timer_deadline = true;
-	} else if (l1_scaled_tsc < vmx->nested.preemption_timer_deadline)
-		timer_value = vmx->nested.preemption_timer_deadline -
-			      l1_scaled_tsc;
-	return timer_value;
+	}
+	return vmx->nested.preemption_timer_deadline - l1_scaled_tsc;
 }
 
 static void vmx_start_preemption_timer(struct kvm_vcpu *vcpu,


Thanks,

Paolo