[PATCH 3.17 132/319] kvm: x86: dont kill guest on unknown exit reason

From: Greg Kroah-Hartman
Date: Tue Nov 11 2014 - 20:26:27 EST


3.17-stable review patch. If anyone has any objections, please let me know.

------------------

From: "Michael S. Tsirkin" <mst@xxxxxxxxxx>

commit 2bc19dc3754fc066c43799659f0d848631c44cfe upstream.

KVM_EXIT_UNKNOWN is a kvm bug, we don't really know whether it was
triggered by a priveledged application. Let's not kill the guest: WARN
and inject #UD instead.

Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
arch/x86/kvm/svm.c | 6 +++---
arch/x86/kvm/vmx.c | 6 +++---
2 files changed, 6 insertions(+), 6 deletions(-)

--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -3534,9 +3534,9 @@ static int handle_exit(struct kvm_vcpu *

if (exit_code >= ARRAY_SIZE(svm_exit_handlers)
|| !svm_exit_handlers[exit_code]) {
- kvm_run->exit_reason = KVM_EXIT_UNKNOWN;
- kvm_run->hw.hardware_exit_reason = exit_code;
- return 0;
+ WARN_ONCE(1, "vmx: unexpected exit reason 0x%x\n", exit_code);
+ kvm_queue_exception(vcpu, UD_VECTOR);
+ return 1;
}

return svm_exit_handlers[exit_code](svm);
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -7058,10 +7058,10 @@ static int vmx_handle_exit(struct kvm_vc
&& kvm_vmx_exit_handlers[exit_reason])
return kvm_vmx_exit_handlers[exit_reason](vcpu);
else {
- vcpu->run->exit_reason = KVM_EXIT_UNKNOWN;
- vcpu->run->hw.hardware_exit_reason = exit_reason;
+ WARN_ONCE(1, "vmx: unexpected exit reason 0x%x\n", exit_reason);
+ kvm_queue_exception(vcpu, UD_VECTOR);
+ return 1;
}
- return 0;
}

static void update_cr8_intercept(struct kvm_vcpu *vcpu, int tpr, int irr)


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