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=78311a514099932cd8434d5d2194aa94e56ab67c;p=linux.git

KVM: x86: ignore APICv if LAPIC is not enabled

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>
---

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 5a403d92833f5..441f4769173e0 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -9849,7 +9849,7 @@ 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))) {