Gpu passthrough performance/usage

User Support General
1

Hello, I’m on Qubes 4.2, kernel version 6.1.75-1.
I have some problems with gpu passthrough, specifically the performance or telling the Qube to use that attached GPU as main one, as a test I launched minecraft and I was doing 10-16fps, I have a 6000th series AMD gpu that can do well over 100 on bare metal.

I got the confirm the GPU is passed to the qube by doing a neofetch and there was in the gpu section, mine.

The passthrough was done by:
1) Appending rd.qubes.hide_pci=00:00.0 in grub config at /etc/default/grub
2) Creating a new qube and passing the [VGA CONTROLLER] the gpu and its Audio device that I didn’t add in hide_pci line in grub as it would just halt my system.
3) Seeing if on my debian-12 fresh qube there were AMD drivers (pog they are preinstalled)

2

Are you using separate display and keyboard/mouse for your qube with GPU attached? Or VNC/VirtualGL/something else?
Are you sure that you’re using the attached GPU?
You can check it using glxinfo:

3

How would I do that? I attached my second monitor to GPU DP port, but it doesn’t output anything on the screen.

Mouse yes, not keyboard as it seems to work fine.

lspci -vnnn | perl -lne 'print if /^\d+\:.+(\[\S+\:\S+\])/' | grep VGA

00:04.0 VGA compatible controller [0300]: Device [1234:1111] (rev 02) (prog-if 00 [VGA controller])

00:07.0 VGA compatible controller [0300]: Advanced Micro Devices, Inc. [AMD/ATI] Navi 22 [Radeon RX [gpu model] [1002:73df] (rev c1) (prog-if 00 [VGA controller])

It should as VGA controller is last on gpu one and other vga controller

4

You can follow this guide to configure VM with GPU passthrough:

5

That’s not useful at all, I asked how to use second Monitor with gpu and you just linked useless pile of things I don’t need at all, I don’t need a WM or mnk drivers

6

It doesn’t even explain how to setup a WM for the user