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From: "Radim Krčmář" <rkrcmar@redhat.com>
To: linux-kernel@vger.kernel.org
Cc: kvm@vger.kernel.org, joro@8bytes.org, pbonzini@redhat.com,
	stable@vger.kernel.org
Subject: [PATCH] KVM: SVM: fix NMI window after iret
Date: Fri, 17 Jan 2014 20:52:42 +0100	[thread overview]
Message-ID: <1389988362-15260-1-git-send-email-rkrcmar@redhat.com> (raw)

We should open NMI window right after an iret, but SVM exits before it.
We wanted to single step using the trap flag and then open it.
(or we could emulate the iret instead)
We don't do it since commit 3842d135ff2 (likely), because the iret exit
handler does not request an event, so NMI window remains closed until
the next exit.

Fix this by making KVM_REQ_EVENT request in the iret handler.

Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
---
 (btw. kvm-unit-tests weren't executed on SVM since Nov 2010, at least)

 arch/x86/kvm/svm.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index c7168a5..b5a735b 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -2829,6 +2829,7 @@ static int iret_interception(struct vcpu_svm *svm)
 	clr_intercept(svm, INTERCEPT_IRET);
 	svm->vcpu.arch.hflags |= HF_IRET_MASK;
 	svm->nmi_iret_rip = kvm_rip_read(&svm->vcpu);
+	kvm_make_request(KVM_REQ_EVENT, &svm->vcpu);
 	return 1;
 }
 
-- 
1.8.5.2


             reply	other threads:[~2014-01-17 19:54 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-01-17 19:52 Radim Krčmář [this message]
2014-01-17 20:18 ` [PATCH] KVM: SVM: fix NMI window after iret Greg KH
2014-01-17 20:29   ` Radim Krčmář
2014-02-18  9:18 ` Paolo Bonzini

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