On Fri, Jul 04, 2014 at 08:28:25AM +0200, Paolo Bonzini wrote: > Il 03/07/2014 21:09, Jesse Barnes ha scritto: > >Practically speaking, we could probably assume specific CPU/PCH combos, > >as I don't think they're generally mixed across generations, though SNB > >and IVB did have compatible sockets, so there is the possibility of > >mixing CPT and PPT PCHs, but those are register identical as far as the > >graphics driver is concerned, so even that should be safe. > > I guess the driver could do that if it finds an unknown PCH device ID. I would say if possible, do this unconditionally. If this logic is strictly required then I would also check the subsystem vendor id and skip the PCH tricks if it matches Xen. > But > encoding it in the subsystem device ID could also work and it would be easy > to do in the hypervisor. Right, but that's custom code in the hypervisor as opposed to the generic one. If generic one can work, that's much better. > >Beyond that, the other MCH data we need to look at is mirrored into the > >GPU's MMIO space on current gens. > > Heh, that's exactly the same as the paravirtualized solution we were > suggesting. ;) > > Paolo > > >On older gens, we do need to poke at > >the memory controller a bit to get some info (see > >intel_setup_mchbar()), but that's not true of newer stuff. Looks like > >we only short circuit that on VLV though; we could probably do it on > >SNB+. _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
