On 10/1/21 12:32 PM, Thomas Monjalon wrote:

01/10/2021 10:54, Andrew Rybchenko:

quoted

quoted

quoted

Thomas, if I'm not mistaken, net/mlx5 dv_xmeta_en driver option
is vendor-specific way to address the same problem.

Not exactly, it is configuring the capabilities:
  +------+-----------+-----------+-------------+-------------+
  | Mode | ``MARK``  | ``META``  | ``META`` Tx | FDB/Through |
  +======+===========+===========+=============+=============+
  | 0    | 24 bits   | 32 bits   | 32 bits     | no          |
  +------+-----------+-----------+-------------+-------------+
  | 1    | 24 bits   | vary 0-32 | 32 bits     | yes         |
  +------+-----------+-----------+-------------+-------------+
  | 2    | vary 0-24 | 32 bits   | 32 bits     | yes         |
  +------+-----------+-----------+-------------+-------------+

Sorry, but I don't understand the difference. Negotiate is
exactly about capabilities which we want to use.

The difference is that dv_xmeta_en is not enabling/disabling
the delivery of mark/meta.
It is just extending the scope (cross-domain) and the size.

Enabling/disabling delivery of some bits...

I think this is not covered in your proposal.

Yes, that's true, since it is too specific this way,
but our proposal can help to make the best automatic
choice from above options depending on negotiation
request.

Of course, you can always enforce via the driver option
and reply on negotiate requests in accordance with
enforced configuration.