After one of the recent updates virtual machines managed by LXD won't boot
after being stopped. When you try to start the virtual machine after it's been
stopped the console output remains empty. You can start fresh virtual machines.

Steps to reproduce:

1. Prerequisites: LXD initialized and running
2. Initialize virtual machine `lxc init images:opensuse/15.4 vmtest --vm`
3. Start the virtual machine `lxc start vmtest`
4. Wait a while and verify that you can access the shell `lxc shell vmtest`
5. Stop the virtual machine `lxc stop vmtest`
6. Start the virtual machine `lxc start vmtest` or `lxc start vmtest --console`
to see the console, which will be empty as virtual machine refuses to start.


Actual results:

Virtual machine fails to start, console output is empty.


Expected result:

Virtual machine should start normally and you should see the output in the
console, when you start it with `lxc start vmtest --console`


Date & Hardware:

Update took place 2022-12-01 around 1:19 CET. From the logs it seems qemu
packages were upgraded from 7.1.0-6.1 to 7.1.0-5.1, which may be the cause of
the problem. 

I have two machines with Tumbleweed: transactional server (x86_64 Intel Xeon)
and a desktop (x86_64 AMD Ryzen). Both seem to suffer from this issue.


Additional notes:

For more details and investigation of this issue you may check out
https://discuss.linuxcontainers.org/t/vm-wont-start-empty-console-output/15841