Re: [PATCH v4 net-next 1/8] sfc: add devlink support for ef100

On Thu, 2 Feb 2023 09:24:56 +0000 Martin Habets wrote:

quoted

FWIW I'd just take the devl lock in the main driver code.
devlink should be viewed as a layer between bus and driver rather 
than as another subsystem the driver registers with. Otherwise reloads
and port creation get awkward.  

I see it a bit differently. For me devlink is another subsystem, it even is
an optional subsystem.
At the moment we don't support devlink port for VFs. If needed we'll add that
at some point, but likely only for newer NICs.

That's fine. I believe the structure I suggest is the easiest one 
to get right, but it's not a hard requirement.

Do you think vDPA and RDMA devices will ever register with devlink?

Good question, I can't speak for the entire project but personally 
I have little interest in interfaces to proprietary world, 
so I hope not.

At the moment I don't see devlink port ever applying to our older hardware,
like our sfn8000 or X2 cards. I do think devlink info and other commands
could apply more generally.

There definitely is a need to evolve to another layer between bus and
devices, and devlink can be used to administer that. But that does not
imply the reverse, that all devices register as devlink devices.
For security we would want to limit some operations (such as port creation)
to specific devlink instance(s). For example, normally we would not want a
tennant VM to flash new firmware that applies to the whole NIC.
I hope this makes sense.