On 9/29/21 2:13 PM, Singh, Aman Deep wrote:

On 9/13/2021 4:56 PM, Andrew Rybchenko wrote:

quoted

From: Viacheslav Galaktionov <redacted>

Getting a list of representors from a representor does not make sense.
Instead, a parent device should be used.

To this end, extend the rte_eth_dev_data structure to include the port ID
of the backing device for representors.

Signed-off-by: Viacheslav Galaktionov
[off-list ref]
Signed-off-by: Andrew Rybchenko <redacted>
Acked-by: Haiyue Wang <redacted>
Acked-by: Beilei Xing <redacted>
---
The new field is added into the hole in rte_eth_dev_data structure.
The patch does not change ABI, but extra care is required since ABI
check is disabled for the structure because of the libabigail bug [1].
It should not be a problem anyway since 21.11 is a ABI breaking release.

Potentially it is bad for out-of-tree drivers which implement
representors but do not fill in a new parert_port_id field in
rte_eth_dev_data structure. Get ID by name will not work.

Did we change name of new field from parert_port_id to backer_port_id.

Yes, see v5 changelog below.
It is done to address review notes from Ferruh on v4.

quoted

mlx5 changes should be reviwed by maintainers very carefully, since
we are not sure if we patch it correctly.

[1] https://sourceware.org/bugzilla/show_bug.cgi?id=28060

v5:
     - try to improve name: backer_port_id instead of parent_port_id
     - init new field to RTE_MAX_ETHPORTS on allocation to avoid
       zero port usage by default

v4:
     - apply mlx5 review notes: remove fallback from generic ethdev
       code and add fallback to mlx5 code to handle legacy usecase

v3:
     - fix mlx5 build breakage

v2:
     - fix mlx5 review notes
     - try device port ID first before parent in order to address
       backward compatibility issue

[snip]