From b9e4281361290be50b0caea2951af1c68815ec06 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 commit a58a66afc464d6d2ec294cd3102f36f3652e7ce4 upstream. 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 Signed-off-by: Greg Kroah-Hartman --- 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 0c8230a88bbf..bdb27eb7a9c7 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; -- 2.50.1