Hello,
Thanks for the reply.
doesn't qemu actually panic on entry failure? note i don't have crashes
nor anything in logs, I've tried to enable ignore_msrs in kvm parameters
to see if maybe this will report something, but no luck.
Tracing data are here: https://transfer.sh/1lfnMc/kvmtrace.gz
Also unsure if I didn't lose some data in the process, although if this
was actually three reboots, not just instantly going to recovery, it
shouldn't matter.
I definitely cannot get anything useful from it.
W dniu 24.03.2023 o 15:40, Sean Christopherson pisze:
On Fri, Mar 24, 2023, Michał Zegan wrote:
Hi,
I've sent this some time ago, but was not subscribed here, so unsure if I
didn't get a reply or maybe missed it, so repeating:
I have a linux host with cpu intel core i7 12700h, kernel currently 6.2,
fedora37.
I have a kvm/qemu/libvirt virtual machine, cpu model set to host, machine
type q35, uefi with secureboot enabled, smm on.
The kvm_intel module has nested=y set in parameters so nested virtualization
is enabled on host.
The virtual machine has windows11 pro guest installed.
When I install hyperv/virtualization platform/other similar functions, after
reboot, the windows does not boot. Namely it reboots three times and then
goes to recovery.
This is going to be nearly impossible to debug without more information. Assuming
you can't extract more information from the guest, can you try enabling KVM
tracepoints? E.g. to see if KVM is injecting an exception or a nested VM-Entry
failure that leads to the reboot.
I.e. enable tracing
echo 1 > /sys/kernel/debug/tracing/tracing_on
and then to get the full blast from the trace firehose:
echo 1 > /sys/kernel/debug/tracing/events/kvm/enable
or to get slightly less noisy log:
echo 1 > /sys/kernel/debug/tracing/events/kvm/kvm_entry/enable
echo 1 > /sys/kernel/debug/tracing/events/kvm/kvm_exit/enable
echo 1 > /sys/kernel/debug/tracing/events/kvm/kvm_inj_exception/enable
echo 1 > /sys/kernel/debug/tracing/events/kvm/kvm_nested_intercepts/enable
echo 1 > /sys/kernel/debug/tracing/events/kvm/kvm_nested_intr_vmexit/enable
echo 1 > /sys/kernel/debug/tracing/events/kvm/kvm_nested_vmenter_failed/enable
echo 1 > /sys/kernel/debug/tracing/events/kvm/kvm_nested_vmexit/enable
echo 1 > /sys/kernel/debug/tracing/events/kvm/kvm_nested_vmexit_inject/enable
echo 1 > /sys/kernel/debug/tracing/events/kvm/kvm_nested_vmenter/enable
To capture something useful, you may need to (significantly) increase the size of
the buffer,
echo 131072 > /sys/kernel/debug/tracing/buffer_size_kb
The log itself can be found at
/sys/kernel/debug/tracing/trace
