From: "Suthikulpanit, Suravee" Date: Fri, 3 May 2019 06:38:53 -0700 Subject: kvm: svm/avic: Do not send AVIC doorbell to self Git-commit: 0532dd52dfec0cf774188d3e692d50c197bc4210 References: bsc#1140133 Patch-mainline: v5.3-rc1 AVIC doorbell is used to notify a running vCPU that interrupts has been injected into the vCPU AVIC backing page. Current logic checks only if a VCPU is running before sending a doorbell. However, the doorbell is not necessary if the destination CPU is itself. Add logic to check currently running CPU before sending doorbell. Signed-off-by: Suravee Suthikulpanit Reviewed-by: Alexander Graf Signed-off-by: Paolo Bonzini Acked-by: Joerg Roedel --- arch/x86/kvm/svm.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index a7ea34bed3fe..c56f40d430e5 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -5163,10 +5163,13 @@ static void 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)) - wrmsrl(SVM_AVIC_DOORBELL, - kvm_cpu_get_apicid(vcpu->cpu)); - else + if (avic_vcpu_is_running(vcpu)) { + int cpuid = vcpu->cpu; + + if (cpuid != get_cpu()) + wrmsrl(SVM_AVIC_DOORBELL, kvm_cpu_get_apicid(cpuid)); + put_cpu(); + } else kvm_vcpu_wake_up(vcpu); }