From: Paolo Bonzini <pbonzini@redhat.com>
Date: Wed, 17 Nov 2021 12:35:44 +0000 (-0500)
Subject: KVM: x86: ignore APICv if LAPIC is not enabled
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=3a929e1d7e5e0e0fbdbe0dc9ee04638745965108;p=linux.git

KVM: x86: ignore APICv if LAPIC is not enabled

commit 78311a514099932cd8434d5d2194aa94e56ab67c upstream.

Synchronize the two calls to kvm_x86_sync_pir_to_irr.  The one
in the reenter-guest fast path invoked the callback unconditionally
even if LAPIC is present but disabled.  In this case, there are
no interrupts to deliver, and therefore posted interrupts can
be ignored.

Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 16c7465619f7a..8acbb10939662 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -9723,7 +9723,7 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu)
 		if (likely(exit_fastpath != EXIT_FASTPATH_REENTER_GUEST))
 			break;
 
-		if (vcpu->arch.apicv_active)
+		if (kvm_lapic_enabled(vcpu) && vcpu->arch.apicv_active)
 			static_call(kvm_x86_sync_pir_to_irr)(vcpu);
 
 		if (unlikely(kvm_vcpu_exit_request(vcpu))) {