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SVM: do not generate "external interrupt exit" if other exit is pending

PATCH Applied Gleb Natapov 3 participants 3 messages Sep 20, 2010

Subsystems (3)
x86 KVM KVM x86
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Gleb Natapov

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#0 lore raw

PATCH v2 1/1 SVM: do not generate "external interrupt exit" if other exit is pending

Nested SVM checks for external interrupt after injecting nested exception. In case there is external interrupt pending the code generates "external interrupt exit" and overwrites previous exit info. If previously injected exception already generated exit it will be lost.

Signed-off-by Gleb Natapov <[email protected]>

---
v1->v2
- Added comment

arch/x86/kvm/svm.c +8 -0
index 43f5558..ca778d5 100644
@@ -1707,6 +1707,14 @@ static inline bool nested_svm_intr(struct vcpu_svm *svm)
 	if (!(svm->vcpu.arch.hflags & HF_HIF_MASK))
 		return false;
 
+	/*
+	 * if vmexit was already requested (by intercepted exception
+	 * for instance) do not overwrite it with "external interrupt"
+	 * vmexit.
+	 */
+	if (svm->nested.exit_required)
+		return false;
+
 	svm->vmcb->control.exit_code   = SVM_EXIT_INTR;
 	svm->vmcb->control.exit_info_1 = 0;
 	svm->vmcb->control.exit_info_2 = 0;

--
Gleb.

Acked-by on v2 1/1
#1 lore raw
Quoted 6 lines · Gleb Natapov

Nested SVM checks for external interrupt after injecting nested exception. In case there is external interrupt pending the code generates "external interrupt exit" and overwrites previous exit info. If previously injected exception already generated exit it will be lost.

Signed-off-by Gleb Natapov <[email protected]>
Acked-by Joerg Roedel <[email protected]>
Quoted 26 lines

---
v1->v2
- Added comment

arch/x86/kvm/svm.c +8 -1
index 43f5558..ca778d5 100644
@@ -1707,6 +1707,14 @@ static inline bool nested_svm_intr(struct vcpu_svm *svm)
 	if (!(svm->vcpu.arch.hflags & HF_HIF_MASK))
 		return false;
 
+	/*
+	 * if vmexit was already requested (by intercepted exception
+	 * for instance) do not overwrite it with "external interrupt"
+	 * vmexit.
+	 */
+	if (svm->nested.exit_required)
+		return false;
+
 	svm->vmcb->control.exit_code   = SVM_EXIT_INTR;
 	svm->vmcb->control.exit_info_1 = 0;
 	svm->vmcb->control.exit_info_2 = 0;
--

Gleb.

Signature · 5 lines
AMD Operating System Research Center

Advanced Micro Devices GmbH Einsteinring 24 85609 Dornach
General Managers: Alberto Bozzo, Andrew Bowd
Registration: Dornach, Landkr. Muenchen; Registerger. Muenchen, HRB Nr. 43632
Applied
#2 lore raw
In reply to Gleb Natapov
Quoted 9 lines · Gleb Natapov

Nested SVM checks for external interrupt after injecting nested exception. In case there is external interrupt pending the code generates "external interrupt exit" and overwrites previous exit info. If previously injected exception already generated exit it will be lost.

Signed-off-by Gleb Natapov <[email protected]>

---
v1->v2
- Added comment

Applied, thanks.