On Sun, Mar 12, 2017 at 11:16:44AM +0000, Mark Cave-Ayland wrote: > On 12/03/17 03:56, Michael S. Tsirkin wrote: > > > After looking at it some more, I think the issue is merely with how info > > mtree presents information, which confuses instead of helping when > > overlap triggers. Specifically > > 000001ff00000000-000001ffffffffff (prio 0, i/o): pci-mmio > > ... > > 000001fe04040000-000001fe04043fff (prio 1, i/o): virtio-pci > > > > really means that virtio-pci is not visible at all, this > > happens because it starts at offset ffffffff04040000 which is > > outside the parent. > > > > I think that the cleanest fix is probably to show 128 bit addresses, > > then user will see the real addresses: > > > > 000001ff00000000-000001ffffffffff (prio 0, i/o): pci-mmio > > ... > > 1000001fe04040000-1000001fe04043fff (prio 1, i/o): virtio-pci > > > > and now it's clear what is going on: virtio-pci is outside pci-mmio. > > > > This would have pointed Mark in the right direction earlier. > > > > Thoughts? Patch? > > Presumably if someone tried to do this on real hardware, the BAR address > would lie outside of the pci-mmio region and effectively isn't mapped? > > If this is the case I'd be happy with a simple qemu_log() showing the > full 64-bit address and region name explaining that it couldn't be > mapped underneath its parent because it was outside its parent region, > and skip the mapping. > > > ATB, > > Mark.
I think that's what happens anyway. The bug is merely the desplay in info mtree which uses 64 bit math. -- MST
