Commit 0532dd52 authored May 03, 2019 by Suthikulpanit, Suravee Committed by Paolo Bonzini Jun 04, 2019

kvm: svm/avic: Do not send AVIC doorbell to self



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 <suravee.suthikulpanit@amd.com>
Reviewed-by: Alexander Graf <graf@amazon.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

parent b6c4bc65

arch/x86/kvm/svm.c

+7 −4

Original line number	Diff line number	Diff line
		@@ -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);
		}

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