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| author | Jan Kiszka <jan.kiszka@siemens.com> | 2011-10-18 16:23:11 (GMT) |
|---|---|---|
| committer | Avi Kivity <avi@redhat.com> | 2011-10-30 10:24:10 (GMT) |
| commit | f1c1da2bde712812a3e0f9a7a7ebe7a916a4b5f4 (patch) | |
| tree | db3715f38fd012cece847d0f0918cbc12eb2123f | |
| parent | 7697e71f72b45a1bd0abe70918c383100fcc8514 (diff) | |
| download | linux-f1c1da2bde712812a3e0f9a7a7ebe7a916a4b5f4.tar.xz | |
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.c | 1 |
1 files changed, 0 insertions, 1 deletions
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index e7ed4b1..e32243e 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); |