Re: [dpdk-dev] [PATCH v5] ethdev: fix representor port ID search by name

[Andrew Rybchenko <andrew.rybchenko@oktetlabs.ru>]

On 9/29/21 2:13 PM, Singh, Aman Deep wrote:
> 
> On 9/13/2021 4:56 PM, Andrew Rybchenko wrote:
>> From: Viacheslav Galaktionov <viacheslav.galaktionov@oktetlabs.ru>
>>
>> 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
>> <viacheslav.galaktionov@oktetlabs.ru>
>> Signed-off-by: Andrew Rybchenko <andrew.rybchenko@oktetlabs.ru>
>> Acked-by: Haiyue Wang <haiyue.wang@intel.com>
>> Acked-by: Beilei Xing <beilei.xing@intel.com>
>> ---
>> 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.

>>
>> 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]