[PATCH 34/35] KVM: VMX: Report unexpected simultaneous exceptions as internal errors

Avi Kivity
2009-11-19T13:35:09Z

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 c0e66dd..22fcd27 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -2744,9 +2744,14 @@ 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 172639e..976f4d1 100644
--- a/include/linux/kvm.h
+++ b/include/linux/kvm.h
@@ -163,6 +163,7 @@ 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