[PATCH 2/2] KVM: VMX: Report unexpected simultaneous exceptions as internal errors

[Avi Kivity <avi@redhat.com>]

These happen when we trap an exception when another exception is being
delivered; we only expect these with MCEs and page faults.  If something
unexpected happens, things probably went south and we're better off reporting
an internal error and freezing.

Signed-off-by: Avi Kivity <avi@redhat.com>
---
 arch/x86/kvm/vmx.c  |   11 ++++++++---
 include/linux/kvm.h |    1 +
 2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 85a7363..8b8eaac 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -2738,9 +2738,14 @@ static int handle_exception(struct kvm_vcpu *vcpu)
 		return handle_machine_check(vcpu);
 
 	if ((vect_info & VECTORING_INFO_VALID_MASK) &&
-						!is_page_fault(intr_info))
-		printk(KERN_ERR "%s: unexpected, vectoring info 0x%x "
-		       "intr info 0x%x\n", __func__, vect_info, intr_info);
+	    !is_page_fault(intr_info)) {
+		vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+		vcpu->run->internal.suberror = KVM_INTERNAL_ERROR_SIMUL_EX;
+		vcpu->run->internal.ndata = 2;
+		vcpu->run->internal.data[0] = vect_info;
+		vcpu->run->internal.data[1] = intr_info;
+		return 0;
+	}
 
 	if ((intr_info & INTR_INFO_INTR_TYPE_MASK) == INTR_TYPE_NMI_INTR)
 		return 1;  /* already handled by vmx_vcpu_run() */
diff --git a/include/linux/kvm.h b/include/linux/kvm.h
index 6d27513..089cad7 100644
--- a/include/linux/kvm.h
+++ b/include/linux/kvm.h
@@ -99,6 +99,7 @@ struct kvm_pit_config {
 
 /* For KVM_EXIT_INTERNAL_ERROR */
 #define KVM_INTERNAL_ERROR_EMULATION 1
+#define KVM_INTERNAL_ERROR_SIMUL_EX 2
 
 /* for KVM_RUN, returned by mmap(vcpu_fd, offset=0) */
 struct kvm_run {
-- 
1.6.5.2