Re: [Qemu-devel] Re: [PATCH] PCI: Bus number from the bridge, not the device

[Gleb Natapov]

On Sun, Nov 21, 2010 at 10:39:31PM +0200, Michael S. Tsirkin wrote:
> On Sun, Nov 21, 2010 at 09:29:59PM +0200, Gleb Natapov wrote:
> > > We can control the bus numbers that the BIOS will assign to pci root.
> > And if you need to insert device that sits behind pci-to-pci bridge? Do
> > you want to control that bus address too? And bus number do not 
> > unambiguously
> > describe pci root since two roots can have same bus number just fine.
> 
> They have to have different segment numbers.
> 
AKA PCI domains AKA one more number assigned by a guest.

> > > It's probably required to make them stable anyway.
> > > 
> > Why?
> 
> To avoid bus renumbering on reboot after you add a pci-to-pci bridge.
> 
Why should qemu care?

--
                        Gleb.