Re: [RFC net-next v2 1/2] devlink: add whole device devlink instance

[Jiri Pirko]

Wed, Feb 19, 2025 at 05:32:54PM +0100, przemyslaw.kitszel@xxxxxxxxx wrote:
>Add a support for whole device devlink instance. Intented as a entity
>over all PF devices on given physical device.
>
>In case of ice driver we have multiple PF devices (with their devlink
>dev representation), that have separate drivers loaded. However those
>still do share lots of resources due to being the on same HW. Examples
>include PTP clock and RSS LUT. Historically such stuff was assigned to
>PF0, but that was both not clear and not working well. Now such stuff
>is moved to be covered into struct ice_adapter, there is just one instance
>of such per HW.
>
>This patch adds a devlink instance that corresponds to that ice_adapter,
>to allow arbitrage over resources (as RSS LUT) via it (further in the
>series (RFC NOTE: stripped out so far)).
>
>Thanks to Wojciech Drewek for very nice naming of the devlink instance:
>PF0:		pci/0000:00:18.0
>whole-dev:	pci/0000:00:18
>But I made this a param for now (driver is free to pass just "whole-dev").
>
>$ devlink dev # (Interesting part of output only)
>pci/0000:af:00:
>  nested_devlink:
>    pci/0000:af:00.0
>    pci/0000:af:00.1
>    pci/0000:af:00.2
>    pci/0000:af:00.3
>    pci/0000:af:00.4
>    pci/0000:af:00.5
>    pci/0000:af:00.6
>    pci/0000:af:00.7

Please check my RFC attempt to solve this for mlx5:
https://lore.kernel.org/all/20250318124706.94156-1-jiri@xxxxxxxxxxx/

I believe that the same could work for you too.