On 01/29/2013 02:59 PM, Thomas Petazzoni wrote:

Arnd,

On Tue, 29 Jan 2013 21:33:08 +0100, Thomas Petazzoni wrote:

quoted

Basically, I have currently two suggestions:

 * From Jason Gunthorpe, to not use any host bridge, and instead use
   only PCI-to-PCI bridges, one per PCIe interface.

 * From you, to not use any PCI-to-PCI bridge, and use only host
   bridges, one per PCIe interface.

Thinking more about this, this solution (using one emulated host bridge
per PCIe interface) would cause one problem: the PCIe device itself
would no longer be in slot 0.

I think that's device 0 not slot 0 right?

If I'm correct, with one host bridge per PCIe interface, we would have
the following topology:

 bus 0, slot 0: emulated host bridge 0
 bus 0, slot 1: PCIe device connected to PCIe interface 0

I /think/ the bus that the root port itself is on is different from the
bus that the downstream device is on, so wouldn't you end up with:

bus 0, slot 0: emulated host bridge 0
bus 1, slot 0: PCIe device connected to PCIe interface 0

(and isn't that "root port" not "host bridge" in the first line above?)