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From:   Ben Hutchings <ben@decadent.org.uk>
To:     linux-kernel@vger.kernel.org, stable@vger.kernel.org
CC:     akpm@linux-foundation.org, Denis Kirjanov <kda@linux-powerpc.org>,
        "Paolo Bonzini" <pbonzini@redhat.com>,
        "Oliver Upton" <oupton@google.com>
Date:   Fri, 24 Apr 2020 00:07:24 +0100
Message-ID: <lsq.1587683028.625278815@decadent.org.uk>
Subject: [PATCH 3.16 217/245] KVM: nVMX: Don't emulate instructions in
 guest mode
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3.16.83-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Paolo Bonzini <pbonzini@redhat.com>

commit 07721feee46b4b248402133228235318199b05ec upstream.

vmx_check_intercept is not yet fully implemented. To avoid emulating
instructions disallowed by the L1 hypervisor, refuse to emulate
instructions by default.

[Made commit, added commit msg - Oliver]
Signed-off-by: Oliver Upton <oupton@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[bwh: Backported to 3.16: adjust filename, context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
 arch/x86/kvm/vmx.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -8938,7 +8938,7 @@ static int vmx_check_intercept(struct kv
 			       struct x86_instruction_info *info,
 			       enum x86_intercept_stage stage)
 {
-	return X86EMUL_CONTINUE;
+	return X86EMUL_UNHANDLEABLE;
 }
 
 static struct kvm_x86_ops vmx_x86_ops = {