On Mon, Jan 25, 2021 at 12:09 PM Edwin Peer <edwin.peer@broadcom.com> wrote:
>
> On Mon, Jan 25, 2021 at 11:49 AM Jason Gunthorpe <jgg@nvidia.com> wrote:
>
> > I've never seen someone implement a NumVF > 256 by co-opting the bus
> > number.
>
> Usually the VF offset already places the VF routing IDs into a
> different bus number range from the PF. That much at least works
> today.
>
> > Can Linux even assign more bus numbers to a port without firmware
> > help? Bus numbers are something that requires the root complex to be
> > aware of to setup routability.
>
> I'm not sure, presumably something already infers this for the first
> additional bus number based on the SR-IOV config capability?
>

Yes, this should work.  During enumeration, it sees that a device
capable of SRIOV needs more than one bus number and will assign the
proper primary and secondary bus numbers to the upstream bridge.