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authorJan Kiszka <jan.kiszka@siemens.com>2011-10-18 18:23:11 +0200
committerAvi Kivity <avi@redhat.com>2011-10-30 12:24:10 +0200
commitf1c1da2bde712812a3e0f9a7a7ebe7a916a4b5f4 (patch)
treedb3715f38fd012cece847d0f0918cbc12eb2123f
parent7697e71f72b45a1bd0abe70918c383100fcc8514 (diff)
KVM: SVM: Keep intercepting task switching with NPT enabled
AMD processors apparently have a bug in the hardware task switching support when NPT is enabled. If the task switch triggers a NPF, we can get wrong EXITINTINFO along with that fault. On resume, spurious exceptions may then be injected into the guest. We were able to reproduce this bug when our guest triggered #SS and the handler were supposed to run over a separate task with not yet touched stack pages. Work around the issue by continuing to emulate task switches even in NPT mode. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
-rw-r--r--arch/x86/kvm/svm.c1
1 files changed, 0 insertions, 1 deletions
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index e7ed4b1623b9..e32243eac2f4 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -1084,7 +1084,6 @@ static void init_vmcb(struct vcpu_svm *svm)
if (npt_enabled) {
/* Setup VMCB for Nested Paging */
control->nested_ctl = 1;
- clr_intercept(svm, INTERCEPT_TASK_SWITCH);
clr_intercept(svm, INTERCEPT_INVLPG);
clr_exception_intercept(svm, PF_VECTOR);
clr_cr_intercept(svm, INTERCEPT_CR3_READ);

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