[PATCH v4 10/16] KVM: SVM: add warning for mistmatch between AVIC vcpu state and AVIC inhibition

From: Maxim Levitsky <mlevitsk@redhat.com>
To: kvm@vger.kernel.org
Cc: Jim Mattson <jmattson@google.com>,
	linux-kernel@vger.kernel.org, Wanpeng Li <wanpengli@tencent.com>,
	Borislav Petkov <bp@alien8.de>, Joerg Roedel <joro@8bytes.org>,
	Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>,
	"H. Peter Anvin" <hpa@zytor.com>,
	Paolo Bonzini <pbonzini@redhat.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>,
	Vitaly Kuznetsov <vkuznets@redhat.com>,
	Sean Christopherson <seanjc@google.com>,
	x86@kernel.org (maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)),
	Maxim Levitsky <mlevitsk@redhat.com>
Subject: [PATCH v4 10/16] KVM: SVM: add warning for mistmatch between AVIC vcpu state and AVIC inhibition
Date: Tue, 10 Aug 2021 23:52:45 +0300	[thread overview]
Message-ID: <20210810205251.424103-11-mlevitsk@redhat.com> (raw)
In-Reply-To: <20210810205251.424103-1-mlevitsk@redhat.com>

It is never a good idea to enter a guest on a vCPU when the
AVIC inhibition state doesn't match the enablement of
the AVIC on the vCPU.

Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
---
 arch/x86/kvm/svm/svm.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 4feff53dd1d3..6cb7ffbde03b 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -3781,6 +3781,8 @@ static __no_kcsan fastpath_t svm_vcpu_run(struct kvm_vcpu *vcpu)
 
 	pre_svm_run(vcpu);
 
+	WARN_ON_ONCE(kvm_apicv_activated(vcpu->kvm) != kvm_vcpu_apicv_active(vcpu));
+
 	sync_lapic_to_cr8(vcpu);
 
 	if (unlikely(svm->asid != svm->vmcb->control.asid)) {
-- 
2.26.3

