In qemu, you can load gpu bios from file by adding the info into the config xml.
If ctrl alt f3 didn't work, but you know the ip, you can always ssh in. Enable ssh in the libreelec settings addon first.
If you are passing through a gpu, you need the generic version. The virtual build is for a setup without a physical dedicated gpu, for testing and development purposes.
Which file in which folder should I edit to enable ssh? I can also mount the virtual disk in my ubuntu VM, if the file is not visible in Samba.
I'm not using Qemu but Vmware. Maybe the process will be the same?
snailboy1: as you managed to pass through the video card in kvm, have you had to load GPU bios from file?