VM with GPU passthrough freezes when turning off monitor after proxmox 6.2 upgrade

freebeerz

Renowned Member
Aug 5, 2015
11
2
68
Hi,

My setup:
- upgraded from Promox 6.1 to 6.2
- Linux VM: Fedora 32 with GPU passthrough (AMD Sapphire 280x) => worked fine with Proxmox 6.1
- One monitor with integrated USB hub (keyboard + mouse) plugged into the GPU and USB devices passed through to the VM

I have a very weird bug with the new qemu 5.0 in proxmox 6.2:

When I electrically turn off the monitor by using a switch on the power socket, the VM freezes instantly. No pings. Nothing in dmesg or journalctl. When I turn the screen back on, the picture is frozen to whatever was displayed before. Mouse and keyboard don't work.
I can kill the frozen VM with "qm stop" (it has to do a SIGKILL)

If I just put the screen in standby I don't get any freeze.

Maybe it's the GPU or it could be an issue with the USB devices disappearing suddenly (on standby the hub is still powered)...

In any case, I rolled back to pve-qemu-kvm 4.2.0-1 (apt-get install pve-qemu-kvm=4.2.0-1) and I don't get this issue anymore.

So this feels like some sort of regression in qemu 5...

If anyone has any idea how to debug this issue further? Any qemu logs I could find somewhere?

Thanks!
 

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