[PATCH v2 35/43] KVM: SVM: Signal AVIC doorbell iff vCPU is in guest mode
Sean Christopherson <[email protected]>
| Newsgroups | org.kernel.vger.kvm-ppc,dev.linux.lists.kvmarm,org.infradead.lists.kvm-riscv,org.infradead.lists.linux-arm-kernel,org.infradead.lists.linux-riscv,org.kernel.vger.kvm,org.kernel.vger.linux-kernel,org.kernel.vger.linux-mips |
|---|---|
| Message-ID | <[email protected]> |
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 <[email protected]> --- 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