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| author | Radim Krčmář <rkrcmar@redhat.com> | 2014-03-11 19:11:18 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-03-23 21:37:07 -0700 |
| commit | 18bd55f61fa9f46082820741d753b3b919244d8a (patch) | |
| tree | 3b7dbb24858d36e878cc2a0045fcfb8cab35f240 | |
| parent | 7dab50632efb9ed42ee352c3588a3e107dff66bb (diff) | |
| download | lwn-18bd55f61fa9f46082820741d753b3b919244d8a.tar.gz lwn-18bd55f61fa9f46082820741d753b3b919244d8a.zip | |
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>
| -rw-r--r-- | arch/x86/kvm/svm.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index e334389e1c75..b567285efceb 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -3007,10 +3007,8 @@ 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; @@ -3566,6 +3564,8 @@ static void update_cr8_intercept(struct kvm_vcpu *vcpu, int tpr, int irr) if (is_guest_mode(vcpu) && (vcpu->arch.hflags & HF_VINTR_MASK)) return; + clr_cr_intercept(svm, INTERCEPT_CR8_WRITE); + if (irr == -1) return; |