On Wed, Nov 28, 2012 at 01:50:53PM +1100, David Gibson wrote: > On Tue, Nov 27, 2012 at 02:36:57PM +0200, Michael S. Tsirkin wrote: > > On Tue, Nov 27, 2012 at 05:07:31PM +1100, David Gibson wrote: > > > Hi Michael, Alex, > > > > > > This patch represents a compromise I hope will be acceptable after the > > > long thread discussing handling of multiple PCI host bridges on the > > > pseries machine. Patch 1/1 is just a preliminary enforcing uniqueness > > > of LIOBNs in the IOMMU code. > > > > > > Patch 2/2 is the meat. It allows either explicit configuration of all > > > the properties, or the user can just set an abstract index which will > > > generate sensible and probably-unique values for all the rest. > > > > > > With these patches I was able to do something like: > > > qemu-system-ppc64 -M pseries -m 1024 -nographic \ > > > fc17-root.qcow2 -net none -device nec-usb-xhci -device \ > > > spapr-pci-host-bridge,index=1 -device e1000,netdev=fred \ > > > -netdev user,id=fred > > > > > > I was able to see both the PCI domains in the guest, and use the NIC > > > on the secondary domain. > > > > > > There are still some gotches with multiple domains though. The domain > > > value in PCIHostBus is still always initialized to 0, and there are > > > other places in the PCI core where handling of multiple domains is > > > essentially stubbed out. > > > > > > Michael, any thoughts on what to do about that? I could fix up the > > > PCI code so that domain is actually set and used. But I think the > > > whole notion of domain numbers is kind of bogus on the qemu side: > > > since PCI domains are completely independent from each other, it's > > > only platform convention which determines what the domain numbers are. > > > On platforms that don't have a strong convention, the guest will > > > number them itself and we have no way of knowing that. So it seems to > > > me that the PCI code should instead of domain numbers just use the > > > device ID, or the bus name or some qemu side symbolic name. For > > > platforms that do have a numbering convention those names can be > > > derived from the domain numbers, but it also works for platforms that > > > don't. > > > > I agree with this last statement: using bus numbers and domain > > numbers is not a good idea. We mostly need to support domain 0 > > to mean "default" for backwards compatibility. > > Ok. Where are domain numbers actually specified by the qemu user?
pci_parse_devaddr > -- > David Gibson | I'll have my music baroque, and my code > david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ > _other_ > | _way_ _around_! > http://www.ozlabs.org/~dgibson
