Xorg errors while attempting gpu passthrough

[apparatus]

Check the dmesg/journalctl in the qube, maybe you’re missing your GPU firmware or there is some driver issue.
Also did you generate your own Xorg config? E.g.:

@solene

use X :1 -configure to generate an xorg.conf file, then remove all extra in it to just keep the screen/monitor/device related to the VGA card itself was good enough, check you are using nvidia for NVIDIA cards and amdgpu for AMD cards