Re: [PATCH v2 35/43] KVM: SVM: Signal AVIC doorbell iff vCPU is in guest mode

From: Paolo Bonzini
Date: Mon Oct 25 2021 - 10:26:38 EST


On 09/10/21 04:12, Sean Christopherson wrote:
+ */
+ if (vcpu->mode == IN_GUEST_MODE) {
int cpu = READ_ONCE(vcpu->cpu);
/*
@@ -687,8 +692,13 @@ int svm_deliver_avic_intr(struct kvm_vcpu *vcpu, int vec)
if (cpu != get_cpu())
wrmsrl(SVM_AVIC_DOORBELL, kvm_cpu_get_apicid(cpu));
put_cpu();
- } else
+ } else {
+ /*
+ * Wake the vCPU if it was blocking. KVM will then detect the
+ * pending IRQ when checking if the vCPU has a wake event.
+ */
kvm_vcpu_wake_up(vcpu);
+ }

Does this still need to check the "running" flag? That should be a strict superset of vcpu->mode == IN_GUEST_MODE.

Paolo