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From:   Yanfei Xu <yanfei.xu@intel.com>
To:     pbonzini@redhat.com, seanjc@google.com, vkuznets@redhat.com,
        wanpengli@tencent.com, jmattson@google.com, joro@8bytes.org,
        tglx@linutronix.de, mingo@redhat.com, bp@alien8.de,
        dave.hansen@linux.intel.com, wei.w.wang@intel.com,
        kan.liang@intel.com
Cc:     x86@kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH v3] KVM: x86: Fix the intel_pt PMI handling wrongly considered from guest
Date:   Mon, 23 May 2022 22:08:21 +0800
Message-Id: <20220523140821.1345605-1-yanfei.xu@intel.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
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When kernel handles the vm-exit caused by external interrupts and NMI,
it always set a type of kvm_intr_type to handling_intr_from_guest to
tell if it's dealing an IRQ or NMI. For the PMI scenario, it could be
IRQ or NMI.
However the intel_pt PMI certainly is a NMI PMI, hence using
kvm_handling_nmi_from_guest() to distinguish if the intel_pt PMI comes
from guest is more appropriate. This modification can avoid the host
wrongly considered the intel_pt PMI comes from a guest once the host
intel_pt PMI breaks the handling of vm-exit of external interrupts.

Fixes: db215756ae59 ("KVM: x86: More precisely identify NMI from guest when handling PMI")
Signed-off-by: Yanfei Xu <yanfei.xu@intel.com>
---
v1->v2:
1.Fix vmx_handle_intel_pt_intr() directly instead of changing the generic function.
2.Tune the commit message.

v2->v3:
Add the NULL pointer check of variable "vcpu".

 arch/x86/kvm/vmx/vmx.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 610355b9ccce..982df9c000d3 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7856,7 +7856,7 @@ static unsigned int vmx_handle_intel_pt_intr(void)
 	struct kvm_vcpu *vcpu = kvm_get_running_vcpu();
 
 	/* '0' on failure so that the !PT case can use a RET0 static call. */
-	if (!kvm_arch_pmi_in_guest(vcpu))
+	if (!vcpu || !kvm_handling_nmi_from_guest(vcpu))
 		return 0;
 
 	kvm_make_request(KVM_REQ_PMI, vcpu);
-- 
2.32.0