On Mon, 7 Mar 2016 18:19:46 +0200 "Michael S. Tsirkin" <mst@xxxxxxxxxx> wrote: > On Mon, Mar 07, 2016 at 05:17:19PM +0100, Igor Mammedov wrote: > > > > So what would happen when PCI MMIO BAR would be mapped over above range, > > > > since guest thinks it's free to use it as unused resource? > > > > > > IIRC, allocating MMIO BAR over RAM would make the MMIO invisible, > > > irrespective of whether the RAM range is being used for anything. > > An then driver would start writing 'garbage' to RAM, resulting in > > strange guest behavior and not work PCI device. > > Do you observe such behaviour? > > > that's why reserving region is a good idea if it could be done. > > Which region? Reserve all of RAM in _CRS? Ops, I'm wrong here since PCI0._CRS doesn't include RAM, it's not needed to reserve region there. > > > > > > > > > > > > > > > > > > > So we should either reserve range or punch a hole in PCI0._CRS. > > > > > > Reserving ranges is simpler and that's what we've switched to > > > > > > from manual hole punching, see PCI/CPU/Memory hotplug and other > > > > > > motherboard resources. > -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
