On Fri, 2016-12-02 at 15:18 +1100, David Gibson wrote:
> But if you pass through multiple groups, things get weird. On q35,
> you'd generally expect physically separate (different slot) devices to
> appear under separate root complexes. Whereas on pseries they'll
> appear as siblings on a virtual bus (which makes no physical sense for
> point-to-point PCI-E).
It's also somewhat broken if they aren't in the same iommu domain
because the way we pass the iommu buid is via the parent node, so
a given iommu domain must reside below a common parent and not share
> I suppose we could try treating all devices on pseries as though they
> were chipset builtin devices on q35, which will appear on the root
> PCI-E bus without root complex. But I suspect that's likely to cause
> trouble with hotplug, and it will certainly need different address
> allocation from libvirt.