Signal the AVIC doorbell iff the vCPU is running in the guest. If the vCPU
is not IN_GUEST_MODE, it's guaranteed to pick up any pending IRQs on the
next VMRUN, which unconditionally processes the vIRR.
Add comments to document the logic.
Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
arch/x86/kvm/svm/avic.c | 14 ++++++++++++--
1 file changed, 12 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kvm/svm/avic.c b/arch/x86/kvm/svm/avic.c
index 208c5c71e827..cbf02e7e20d0 100644
--- a/arch/x86/kvm/svm/avic.c
+++ b/arch/x86/kvm/svm/avic.c
@@ -674,7 +674,12 @@ int svm_deliver_avic_intr(struct kvm_vcpu *vcpu, int vec)
kvm_lapic_set_irr(vec, vcpu->arch.apic);
smp_mb__after_atomic();
- if (avic_vcpu_is_running(vcpu)) {
+ /*
+ * Signal the doorbell to tell hardware to inject the IRQ if the vCPU
+ * is in the guest. If the vCPU is not in the guest, hardware will
+ * automatically process AVIC interrupts at VMRUN.
+ */
+ 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);
+ }
return 0;
}
--
2.33.0.882.g93a45727a2-goog
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