On Wed, Aug 03, 2011 at 11:13:15AM +0100, Stefan Hajnoczi wrote: > On Mon, Aug 01, 2011 at 01:10:38PM +0300, Michael S. Tsirkin wrote: > > On Mon, Aug 01, 2011 at 04:51:02PM +1000, David Gibson wrote: > > > qemu already almost supports PCI domains; that is, several entirely > > > independent PCI host bridges on the same machine. However, a bug in > > > pci_bus_new_inplace() means that every host bridge gets assigned domain > > > number zero and so can't be properly distinguished. This patch fixes the > > > bug, giving each new host bridge a new domain number. > > > > > > Signed-off-by: David Gibson <da...@gibson.dropbear.id.au> > > > > OK, but I'd like to see the whole picture. > > How does the guest detect multiple domains, > > and how does it access them? > > > > > --- > > > hw/pci.c | 5 ++++- > > > 1 files changed, 4 insertions(+), 1 deletions(-) > > > > > > diff --git a/hw/pci.c b/hw/pci.c > > > index 36db58b..2b4aecb 100644 > > > --- a/hw/pci.c > > > +++ b/hw/pci.c > > > @@ -262,6 +262,8 @@ int pci_find_domain(const PCIBus *bus) > > > return -1; > > > } > > > > > > +static int pci_next_domain; /* = 0 */ > > > + > > > void pci_bus_new_inplace(PCIBus *bus, DeviceState *parent, > > > const char *name, > > > MemoryRegion *address_space, > > > @@ -274,7 +276,8 @@ void pci_bus_new_inplace(PCIBus *bus, DeviceState > > > *parent, > > > > > > /* host bridge */ > > > QLIST_INIT(&bus->child); > > > - pci_host_bus_register(0, bus); /* for now only pci domain 0 is > > > supported */ > > > + > > > + pci_host_bus_register(pci_next_domain++, bus); > > > > What happens when that overflows? > > In what scenario do we reach such a high number? (I'm not saying this > is harmless, just trying to understand if it should be an assert or > error return.) > > Stefan
Can bus ever get hot-plugged?
