linux-kernel - [PATCH 03/11] KVM: SVM: Check for nested intercepts on NMI injection

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Date:	Wed, 24 Feb 2010 18:59:12 +0100
From:	Joerg Roedel <joerg.roedel@....com>
To:	Avi Kivity <avi@...hat.com>, Marcelo Tosatti <mtosatti@...hat.com>
CC:	Alexander Graf <agraf@...e.de>, kvm@...r.kernel.org,
	linux-kernel@...r.kernel.org, Joerg Roedel <joerg.roedel@....com>
Subject: [PATCH 03/11] KVM: SVM: Check for nested intercepts on NMI injection

This patch implements the NMI intercept checking for nested
svm.

Signed-off-by: Joerg Roedel <joerg.roedel@....com>
---
 arch/x86/kvm/svm.c |   22 +++++++++++++++++++---
 1 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index b821b2f..9759d9f 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -1480,6 +1480,20 @@ static inline bool nested_svm_intr(struct vcpu_svm *svm)
 	return true;
 }
 
+/* This function returns true if it is save to enable the nmi window */
+static inline bool nested_svm_nmi(struct vcpu_svm *svm)
+{
+	if (!is_nested(svm))
+		return true;
+
+	if (!(svm->nested.intercept & (1ULL << INTERCEPT_NMI)))
+		return true;
+
+	svm->vmcb->control.exit_code = SVM_EXIT_NMI;
+	svm->nested.exit_required = true;
+
+	return false;
+}
 static void *nested_svm_map(struct vcpu_svm *svm, u64 gpa, struct page **_page)
 {
 	struct page *page;
@@ -2681,9 +2695,11 @@ static void enable_nmi_window(struct kvm_vcpu *vcpu)
 	 * Something prevents NMI from been injected. Single step over possible
 	 * problem (IRET or exception injection or interrupt shadow)
 	 */
-	svm->nmi_singlestep = true;
-	svm->vmcb->save.rflags |= (X86_EFLAGS_TF | X86_EFLAGS_RF);
-	update_db_intercept(vcpu);
+	if (gif_set(svm) && nested_svm_nmi(svm)) {
+		svm->nmi_singlestep = true;
+		svm->vmcb->save.rflags |= (X86_EFLAGS_TF | X86_EFLAGS_RF);
+		update_db_intercept(vcpu);
+	}
 }
 
 static int svm_set_tss_addr(struct kvm *kvm, unsigned int addr)
-- 
1.7.0


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