From a58a66afc464d6d2ec294cd3102f36f3652e7ce4 Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Fri, 6 Jan 2023 01:12:38 +0000 Subject: [PATCH] KVM: x86: Don't inhibit APICv/AVIC on xAPIC ID "change" if APIC is disabled Don't inhibit APICv/AVIC due to an xAPIC ID mismatch if the APIC is hardware disabled. The ID cannot be consumed while the APIC is disabled, and the ID is guaranteed to be set back to the vcpu_id when the APIC is hardware enabled (architectural behavior correctly emulated by KVM). Fixes: 3743c2f02517 ("KVM: x86: inhibit APICv/AVIC on changes to APIC ID or APIC base") Cc: stable@vger.kernel.org Reviewed-by: Maxim Levitsky Signed-off-by: Sean Christopherson Message-Id: <20230106011306.85230-6-seanjc@google.com> Signed-off-by: Paolo Bonzini --- arch/x86/kvm/lapic.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index 33a661d..191b5a9 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -2072,6 +2072,9 @@ static void kvm_lapic_xapic_id_updated(struct kvm_lapic *apic) { struct kvm *kvm = apic->vcpu->kvm; + if (!kvm_apic_hw_enabled(apic)) + return; + if (KVM_BUG_ON(apic_x2apic_mode(apic), kvm)) return; -- 2.7.4