[Qemu-devel] Re: Hitting 29 NIC limit

[Michael S. Tsirkin]

On Thu, Nov 18, 2010 at 04:09:34PM +0900, Isaku Yamahata wrote:
> On Thu, Nov 18, 2010 at 08:46:43AM +0200, Michael S. Tsirkin wrote:
> > > What is missing for multiple pci buses is
> > > - a new PC machine description which has multiple pci buses
> > >   My Q35 chipset patch will provide this.
> > 
> > IMHO, what we really need is a way to specify bridges
> > through qdev. Not a machine with a hard-coded buses.
> 
> Yes, it's long-term goal.
> 
> 
> > The firmware paths used by Gleb's code might supply
> > a good syntax to specify topology.
> > 
> > > - a simple P2P bridge emulator for pc architecture
> > > - seabios support
> > >   - DSDT for a new machine which has multi pci buses(IRQ routing)
> > >   - pv pci bus numbering
> > 
> > Interesting. What's the motivation for this?
> 
> For hot-plugging pci-to-pci bridge. It requires sparse pci bus numbering.

Not sure I understand. pci bus numbering should be
completely up to the guest.

> In fact, it's not so strong requirement.
> Possibly I would have to dig into dsdt.

Yes, some guest-side technology like acpi might be needed.

> -- 
> yamahata