While debugging a kernel issue, I found that QEMU always reboots when an
x86 triple fault occurs, which complicates debugging. QEMU and libvirt
have a facility for creating a dump when KVM reports
KVM_SYSTEM_EVENT_CRASH. So change the VMX triple fault handler to do
that. This gives user space the ability to decide whether to dump,
pause, shutdown, or reboot.
Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
---
arch/x86/kvm/vmx.c | 3 ++-
include/trace/events/kvm.h | 3 ++-
2 files changed, 4 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 3acde66..1f2694c 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -5731,7 +5731,8 @@ static int handle_external_interrupt(struct kvm_vcpu *vcpu)
static int handle_triple_fault(struct kvm_vcpu *vcpu)
{
- vcpu->run->exit_reason = KVM_EXIT_SHUTDOWN;
+ vcpu->run->exit_reason = KVM_EXIT_SYSTEM_EVENT;
+ vcpu->run->system_event.type = KVM_SYSTEM_EVENT_CRASH;
return 0;
}
diff --git a/include/trace/events/kvm.h b/include/trace/events/kvm.h
index 8ade3eb..200a3d7 100644
--- a/include/trace/events/kvm.h
+++ b/include/trace/events/kvm.h
@@ -14,7 +14,8 @@
ERSN(SHUTDOWN), ERSN(FAIL_ENTRY), ERSN(INTR), ERSN(SET_TPR), \
ERSN(TPR_ACCESS), ERSN(S390_SIEIC), ERSN(S390_RESET), ERSN(DCR),\
ERSN(NMI), ERSN(INTERNAL_ERROR), ERSN(OSI), ERSN(PAPR_HCALL), \
- ERSN(S390_UCONTROL), ERSN(WATCHDOG), ERSN(S390_TSCH)
+ ERSN(S390_UCONTROL), ERSN(WATCHDOG), ERSN(S390_TSCH), \
+ ERSN(SYSTEM_EVENT)
TRACE_EVENT(kvm_userspace_exit,
TP_PROTO(__u32 reason, int errno),
--
2.7.4
