linux-kernel - [PATCH 3.12 106/206] kvm: x86: don't kill guest on unknown exit reason

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Message-Id: <3f119d66b95c31910a5363b15308ff3d18bba29d.1416319692.git.jslaby@suse.cz>
Date:	Tue, 18 Nov 2014 15:07:41 +0100
From:	Jiri Slaby <jslaby@...e.cz>
To:	stable@...r.kernel.org
Cc:	linux-kernel@...r.kernel.org,
	"Michael S. Tsirkin" <mst@...hat.com>,
	Paolo Bonzini <pbonzini@...hat.com>,
	Jiri Slaby <jslaby@...e.cz>
Subject: [PATCH 3.12 106/206] kvm: x86: don't kill guest on unknown exit reason

From: "Michael S. Tsirkin" <mst@...hat.com>

3.12-stable review patch.  If anyone has any objections, please let me know.

===============

commit 2bc19dc3754fc066c43799659f0d848631c44cfe upstream.

KVM_EXIT_UNKNOWN is a kvm bug, we don't really know whether it was
triggered by a priveledged application.  Let's not kill the guest: WARN
and inject #UD instead.

Signed-off-by: Michael S. Tsirkin <mst@...hat.com>
Signed-off-by: Paolo Bonzini <pbonzini@...hat.com>
Signed-off-by: Jiri Slaby <jslaby@...e.cz>
---
 arch/x86/kvm/svm.c | 6 +++---
 arch/x86/kvm/vmx.c | 6 +++---
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 8466c33e5f53..5dcdff58b679 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -3486,9 +3486,9 @@ static int handle_exit(struct kvm_vcpu *vcpu)
 
 	if (exit_code >= ARRAY_SIZE(svm_exit_handlers)
 	    || !svm_exit_handlers[exit_code]) {
-		kvm_run->exit_reason = KVM_EXIT_UNKNOWN;
-		kvm_run->hw.hardware_exit_reason = exit_code;
-		return 0;
+		WARN_ONCE(1, "vmx: unexpected exit reason 0x%x\n", exit_code);
+		kvm_queue_exception(vcpu, UD_VECTOR);
+		return 1;
 	}
 
 	return svm_exit_handlers[exit_code](svm);
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 87e910934286..d1e87ae48513 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -6815,10 +6815,10 @@ static int vmx_handle_exit(struct kvm_vcpu *vcpu)
 	    && kvm_vmx_exit_handlers[exit_reason])
 		return kvm_vmx_exit_handlers[exit_reason](vcpu);
 	else {
-		vcpu->run->exit_reason = KVM_EXIT_UNKNOWN;
-		vcpu->run->hw.hardware_exit_reason = exit_reason;
+		WARN_ONCE(1, "vmx: unexpected exit reason 0x%x\n", exit_reason);
+		kvm_queue_exception(vcpu, UD_VECTOR);
+		return 1;
 	}
-	return 0;
 }
 
 static void update_cr8_intercept(struct kvm_vcpu *vcpu, int tpr, int irr)
-- 
2.1.3

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