Re: [PATCH net-next v2 4/7] devlink: allow subports on devlink PCI ports

[Jakub Kicinski <jakub.kicinski@netronome.com>]

On Mon, 4 Mar 2019 12:08:57 +0100, Jiri Pirko wrote:
> Fri, Mar 01, 2019 at 07:04:50PM CET, jakub.kicinski@netronome.com wrote:
> >PCI endpoint corresponds to a PCI device, but such device
> >can have one more more logical device ports associated with it.
> >We need a way to distinguish those. Add a PCI subport in the
> >dumps and print the info in phys_port_name appropriately.
> >
> >This is not equivalent to port splitting, there is no split
> >group. It's just a way of representing multiple netdevs on
> >a single PCI function.
> >
> >Note that the quality of being multiport pertains only to
> >the PCI function itself. A PF having multiple netdevs does
> >not mean that its VFs will also have multiple, or that VFs
> >are associated with any particular port of a multiport VF.
> >
> >Example (bus 05 device has subports, bus 82 has only one port per
> >function):  
> 
> How do you plan to added/remove these subports?

I can't say I got that figured out fully, but I was wondering if we can
have some form of:

$ devlink partition pci/0000:82:00.0 new
pci/0000:82:00.0/1001002

Which would create appropriate sub-port and port (-repr-) netdev.

Plus optionally the ability to work with something like the already
existing mdev infrastructure for passing to a VM.  But I haven't even
looked at that, yet.