Hi,
BTW can we teach virtio-gpu to look for framebuffer using virtio pci caps?
The virtio-gpu driver doesn't matter much here, it doesn't use it anyway.
Or are there limitations such as only using IO port BARs, or compatibility with BIOS code etc that limit us to specific BARs anyway?
Yes, vgabios code needs to know. Currently it has bar #2 for the vga framebuffer bar hardcoded. It's 16bit code. I don't feel like making the probing more complicated ...
cheers, Gerd