Commit 755c2bf8 authored by Maxim Levitsky's avatar Maxim Levitsky Committed by Paolo Bonzini
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KVM: x86: lapic: don't touch irr_pending in kvm_apic_update_apicv when inhibiting it 



kvm_apic_update_apicv is called when AVIC is still active, thus IRR bits
can be set by the CPU after it is called, and don't cause the irr_pending
to be set to true.

Also logic in avic_kick_target_vcpu doesn't expect a race with this
function so to make it simple, just keep irr_pending set to true and
let the next interrupt injection to the guest clear it.

Signed-off-by: default avatarMaxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20220207155447.840194-9-mlevitsk@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 2b0ecccb

arch/x86/kvm/lapic.c

+6 −1
Original line number Diff line number Diff line
@@ -2306,7 +2306,12 @@ void kvm_apic_update_apicv(struct kvm_vcpu *vcpu) 
		apic->irr_pending = true;

		apic->isr_count = 1;

	} else {

		apic->irr_pending = (apic_search_irr(apic) != -1);

		/*

		 * Don't clear irr_pending, searching the IRR can race with

		 * updates from the CPU as APICv is still active from hardware's

		 * perspective.  The flag will be cleared as appropriate when

		 * KVM injects the interrupt.

		 */

		apic->isr_count = count_vectors(apic->regs + APIC_ISR);

	}

}