path: root/arch
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authorRadim Krčmář <rkrcmar@redhat.com>2014-03-11 19:11:18 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-03-23 21:38:18 -0700
commitc516a4c127a90e5889b72f1ad1b9da4005bba65b (patch)
treefa9d5ff0df79c1dbd17d41e0beb8e0010a4df89a /arch
parent0f8141267dce8a719b294b6fcade653eaae7aa54 (diff)
KVM: SVM: fix cr8 intercept window
commit 596f3142d2b7be307a1652d59e7b93adab918437 upstream. We always disable cr8 intercept in its handler, but only re-enable it if handling KVM_REQ_EVENT, so there can be a window where we do not intercept cr8 writes, which allows an interrupt to disrupt a higher priority task. Fix this by disabling intercepts in the same function that re-enables them when needed. This fixes BSOD in Windows 2008. Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch')
1 files changed, 3 insertions, 3 deletions
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index a14a6eaf871..765210d4d92 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -2985,10 +2985,8 @@ static int cr8_write_interception(struct vcpu_svm *svm)
u8 cr8_prev = kvm_get_cr8(&svm->vcpu);
/* instruction emulation calls kvm_set_cr8() */
r = cr_interception(svm);
- if (irqchip_in_kernel(svm->vcpu.kvm)) {
- clr_cr_intercept(svm, INTERCEPT_CR8_WRITE);
+ if (irqchip_in_kernel(svm->vcpu.kvm))
return r;
- }
if (cr8_prev <= kvm_get_cr8(&svm->vcpu))
return r;
kvm_run->exit_reason = KVM_EXIT_SET_TPR;
@@ -3550,6 +3548,8 @@ static void update_cr8_intercept(struct kvm_vcpu *vcpu, int tpr, int irr)
if (is_guest_mode(vcpu) && (vcpu->arch.hflags & HF_VINTR_MASK))
+ clr_cr_intercept(svm, INTERCEPT_CR8_WRITE);
if (irr == -1)