On Mi, 2015-03-25 at 18:09 +0100, Michael S. Tsirkin wrote:
On Wed, Mar 25, 2015 at 04:37:16PM +0100, Gerd Hoffmann wrote:
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
OK - you are saying all VGA cards use bar #2 for this functionality, so we are just following established practice here?
vgabios checks pci ids to figure. qxl+stdvga use bar #0, vmware-vga bar #1, virtio-vga bar #2.
cheers, Gerd