On Fri, 2021-12-17 at 13:46 -0600, Tom Lendacky wrote: > There's no WARN or PANIC, just a reset. I can look to try and capture some > KVM trace data if that would help. If so, let me know what events you'd > like captured. Could start with just kvm_run_exit? Reason 8 would be KVM_EXIT_SHUTDOWN and would potentially indicate a triple fault. Failing that, I'd want to start littering the real mode code with outputting 'a' 'b' 'c' etc. to the serial port and see if the offending CPU is really in the trampoline somewhere when something goes wrong. I can knock up an example patch to do that (not tonight) but this would be somewhat easier if I could find a machine I can reproduce on. Sadly I only seem to have access to Milan *guests* without nested virt, not bare metal. Got a machine I can log in to?