Re: [Qemu-devel] [PATCH RFC] docs: add PCIe devices placement guidelines

[Laine Stump]

On 10/04/2016 12:10 PM, Laine Stump wrote:
> On 10/04/2016 11:40 AM, Laszlo Ersek wrote:

> > Small correction to your wording though: you don't want to attach the
> > DMI-PCI bridge to the PXB device, but to the extra root bus provided by
> > the PXB.
>
> This made me realize something - the root bus on a pxb-pcie controller
> has a single slot and that slot can accept either a pcie-root-port
> (ioh3420) or a dmi-to-pci-bridge. If you want to have both express and
> legacy PCI devices on the same NUMA node, then you would either need to
> create one pxb-pcie for the pcie-root-port and another for the
> dmi-to-pci-bridge, or you would need to put the pcie-root-port and
> dmi-to-pci-bridge onto different functions of the single slot. Should
> the latter work properly?

We were discussing pxb-pcie today while Dan was trying to get a 
particular configuration working, and there was some disagreement about 
two points that I stated above as fact (but which may just be 
misunderstanding again):

1) Does pxb-pcie only provide a single slot (0)? Or does it provide 32 
slots (0-31) just like the pcie root complex?

2) can you really only plug a pcie-root-port (ioh3420) into a pxb-pcie? 
Or will it accept anything that pcie.0 accepts?