I'm also trying to pass through my Intel iGPU to a VM, but running into issues. It does work on Debian, however not on Fedora Server which I'd like to use. I have tried changing to BIOS mode, even plugged in a dummy HDMI plug, but nothing helped. SELinux is disabled on Fedora to rule out any issues related to that. I even tried using XCP-NG Center which was suggested in an older post, but that didn't help either: https://xcp-ng.org/forum/topic/6211/intel-gpu-passthrough-question/3
I also posted this on the Fedora forum with further details: https://discussion.fedoraproject.org/t/intel-igpu-in-containers/176029
Are there any other things I could try to investigate this further?