Thats fine as long as you don't want to do acceleration or object migration between GTT and VRAM type memory. Now I expect when you give out this advice you
Yes but the VIA doesn't if I recall correctly have any 'VRAM type memory'. It's all effectively in the GART with the 'stolen' pages preloaded into the translation tables by the BIOS at vga init time.
It has fake VRAM type memory but thats really an illusion (although one the driver seems to like to keep up). The GEM changes do mean you can plug the existing allocator in the VIA driver into GEM directly. Whether that would be a good idea or not given the other things you then need to do I don't know - but it does seem to be me to be a stepping stone in the right direction that is much easier to make ?
That is correct. In fact the via driver detects what type of system ram is used so I can limit what resolutions are supported. Its possible that the memory doesn't have the bandwidth to support a very large resolution on older systems.