A method can effectively lock up a VM and any attempt of killing the VM in dom0 lock up the GUI.

[rqwan...@gmail.com]

Currently in my work I encountered VM lock-ups that can be reliably replayed. And each time I must cold reboot my laptop in order to recover.

I have allocated 2 VCPUs to the VM and the triggerer process is single threaded. However when that happens, Qubes VM Manager shows that 50% of the CPU is busy in the mentioned VM. Noticing that my cpu has 4 cores and a recent update disabled hyper-threading, certainly some disaster happened to the VM. I don't know whether Shutdown VM does its job (I believe it should be unlikely), but to make things worse, Kill VM in the Qubes VM Manager locked up the GUI and I cannot even use Ctrl+Alt+Fx to open the other ttys.

The lock up is limited to several instructions in userspace.

Any idea of tracking the problems?

[rqwan...@gmail.com]

For reference I use Qubes 3.2, and the guest is Fedora 28.

[awokd]

rqwan...@gmail.com:

Does qvm-kill from the command line work any better than the GUI?

[rqwan...@gmail.com]

qvm-kill cannot kill the locked up VM. As for GUI lock up I don't know how it works, it may lock after certain period of time or after I operate on Qubes VM Manager; anyway the whole qubes gets locked by the VM _often_.

I used another fedora 26 old VM and got the same result.

[awokd]

You might want to submit an issue on
https://github.com/QubesOS/qubes-issues. Details on how to recreate the
lockup would be needed.