On Thu, May 23, 2013 at 02:04:08PM +0300, Michael S. Tsirkin wrote: > On Thu, May 09, 2013 at 10:31:09AM +1000, David Gibson wrote: > > pci_find_domain() is used in a number of places where we want an id for a > > whole PCI domain (i.e. the subtree under a PCI root bus). The trouble is > > that many platforms may support multiple independent host bridges with no > > hardware supplied notion of domain number. > > > > This patch, therefore, replaces calls to pci_find_domain() with calls to > > a new pci_root_bus_path() returning a string. The new call is implemented > > in terms of a new callback in the host bridge class, so it can be defined > > in some way that's well defined for the platform. When no callback is > > available we fall back on the qbus name. > > > > Most current uses of pci_find_domain() are for error or informational > > messages, so the change in identifiers should be harmless. The exception > > is pci_get_dev_path(), whose results form part of migration streams. To > > maintain compatibility with old migration streams, the PIIX PCI host is > > altered to always supply "0000" for this path, which matches the old domain > > number (since the code didn't actually support domains other than 0). > > > > For the pseries (spapr) PCI bridge we use a different platform-unique > > identifier (pseries machines can routinely have dozens of PCI host > > bridges). Theoretically that breaks migration streams, but given that we > > don't yet have migration support for pseries, it doesn't matter. > > > > Any other machines that have working migration support including PCI > > devices will need to be updated to maintain migration stream compatibility. > > > > Signed-off-by: David Gibson <da...@gibson.dropbear.id.au> > > AFAIK PC is the only one with working migration, yes, but > we have Q35 as well which can be migrated.
Good point, I'll add a similar hook to q35.
--
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
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