Hi, > One question: are we sure all guest OSes we care about can deal with > discontiguous 32-bit PCI MMIO aperture(s)? Personally, I've got no clue. > Is a "naïve" OS imaginable that looks only at the first suitable range > in the _CRS?
Well, I know there is physical hardware doing the same thing, my work station for example: [ ... ] c8000000-f7ffffff : PCI Bus 0000:00 c8000000-c81fffff : PCI Bus 0000:01 e0000000-efffffff : 0000:00:02.0 e0000000-e02fffff : BOOTFB [ ... ] f8000000-fbffffff : PCI MMCONFIG 0000 [bus 00-3f] f8000000-fbffffff : Reserved f8000000-fbffffff : pnp 00:06 fd000000-fe7fffff : PCI Bus 0000:00 fd000000-fdabffff : pnp 00:07 [ ... ] Which of course is no guarantee that no naïve OS exists, but I think the chances that we'll run into trouble with this are rather small. cheers, Gerd