linux-kernel - [PATCH 1/2] KVM: VMX: avoid running vmx_handle_exit

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Message-Id: <20210826095750.1650467-2-mlevitsk@redhat.com>
Date:   Thu, 26 Aug 2021 12:57:49 +0300
From:   Maxim Levitsky <mlevitsk@...hat.com>
To:     kvm@...r.kernel.org
Cc:     Thomas Gleixner <tglx@...utronix.de>,
        Wanpeng Li <wanpengli@...cent.com>,
        Joerg Roedel <joro@...tes.org>,
        "H. Peter Anvin" <hpa@...or.com>,
        Jim Mattson <jmattson@...gle.com>,
        Sean Christopherson <seanjc@...gle.com>,
        Ingo Molnar <mingo@...hat.com>,
        Paolo Bonzini <pbonzini@...hat.com>,
        Vitaly Kuznetsov <vkuznets@...hat.com>,
        x86@...nel.org (maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)),
        Borislav Petkov <bp@...en8.de>,
        linux-kernel@...r.kernel.org (open list:X86 ARCHITECTURE (32-BIT AND
        64-BIT)), Maxim Levitsky <mlevitsk@...hat.com>
Subject: [PATCH 1/2] KVM: VMX: avoid running vmx_handle_exit_irqoff in case of emulation

If we are emulating an invalid guest state, we don't have a correct
exit reason, and thus we shouldn't do anything in this function.

Signed-off-by: Maxim Levitsky <mlevitsk@...hat.com>
---
 arch/x86/kvm/vmx/vmx.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index fada1055f325..0c2c0d5ae873 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -6382,6 +6382,9 @@ static void vmx_handle_exit_irqoff(struct kvm_vcpu *vcpu)
 {
 	struct vcpu_vmx *vmx = to_vmx(vcpu);
 
+	if (vmx->emulation_required)
+		return;
+
 	if (vmx->exit_reason.basic == EXIT_REASON_EXTERNAL_INTERRUPT)
 		handle_external_interrupt_irqoff(vcpu);
 	else if (vmx->exit_reason.basic == EXIT_REASON_EXCEPTION_NMI)
-- 
2.26.3