Subject: Re: [PATCH net-next 6/8] devlink: introduce port's peer netdevs

From: Jiri Pirko <[email-masked]>
Date: Wed, 27 Feb 2019 14:08:29 +0100

Tue, Feb 26, 2019 at 07:24:34PM CET, [email-masked] wrote:
>Devlink ports represent ports of a switch device (or SR-IOV
>NIC which has an embedded switch). In case of SR-IOV when
>PCIe PFs are exposed the PFs which are directly connected
>to the local machine may also spawn PF netdev (much like
>VFs have a port/"repr" and an actual VF netdev).
>
>Allow devlink to expose such linking. There is currently no
>way to find out which netdev corresponds to which PF.
>
>Example:
>
>$ devlink port
>pci/0000:82:00.0/0: type eth netdev p4p1 flavour physical
>pci/0000:82:00.0/10000: type eth netdev eth1 flavour pci_pf pf 0 peer_netdev enp130s0
>pci/0000:82:00.0/10001: type eth netdev eth0 flavour pci_vf pf 0 vf 0
>pci/0000:82:00.0/10002: type eth netdev eth2 flavour pci_vf pf 0 vf 1

Peer as the other side of a "virtual cable". For PF, that is probably
sufficient. But I think what a "peer of devlink port" should be "a
devlink port".

Not sure about VF.

Consider a simple problem of setting up a VF mac address. In legacy, you
do it like this:
$ ip link set eth2 vf 1 mac 00:52:44:11:22:33
However, in new model, you so far cannot do that.

What I was thinking about was some "dummy peer" which would be on the
host. Not sure if only as a "dummy peer devlink port" or even as some
sort of "dummy netdev".

One way or another, it would provide the user some info about which VF
representor is connected to which VF in VM (mac mapping).