Re: [PATCH] doc: fix support table for ETH and VLAN flow items

[Ilya Maximets <i.maximets@ovn.org>]

On 10/12/22 17:30, Thomas Monjalon wrote:
> 07/10/2022 13:55, Ilya Maximets:
>> On 10/7/22 13:50, Ilya Maximets wrote:
>>> On 9/12/22 12:09, Thomas Monjalon wrote:
>>>> 16/03/2022 13:01, Ilya Maximets:
>>>>> 'has_vlan' attribute is only supported by sfc, mlx5 and cnxk.
>>>>> Other drivers doesn't support it.  Most of them (like i40e) just
>>>>> ignore it silently.  Some drivers (like mlx4) never had a full
>>>>> support of the eth item even before introduction of 'has_vlan'
>>>>> (mlx4 allows to match on the destination MAC only).
>>>>>
>>>>> Same for the 'has_more_vlan' flag of the vlan item.
>>>>>
>>>>> Changing the support level to 'partial' for all such drivers.
>>>>> This doesn't solve the issue, but at least marks the problematic
>>>>> drivers.
>>>>
>>>> You changed "eth" and "vlan" from "Y" to "P".
>>>> The field "has_vlan" is part of "rte_flow_item_eth",
>>>> and "has_more_vlan" is part of "rte_flow_item_vlan",
>>>> so I agree we need to change both items to "partial support".
>>>> It looks to be a good change, just needs to more explicit,
>>>> adding this kind of explanation about the fields.
>>>
>>> I can add this to the commit message.  Should I also add
>>> some note alongside the table in that documentation page?
> 
> I'm afraid it can be long and complex to add notes in the page
> about what is missing to get complete support for each feature/PMD.
> I think you can just re-spin with a clear explanation in the commit,
> so PMD maintainers can refer to it.

OK.  v2 sent here:
  https://patches.dpdk.org/project/dpdk/patch/20221013104849.2677995-1-i.maximets@ovn.org/

Sorry, forgot about --in-reply-to.  Can re-post if necessary.

> 
>>>> We missed this patch in 22.07, let's have some progress quickly.
>>>
>>> It was a busy month + PTO, sorry I didn't get to that patch faster.
> 
> No problem, we are still on time for 22.11.
> 
>>>>> Some details are available in:
>>>>>   https://bugs.dpdk.org/show_bug.cgi?id=958
>>>>
>>>> About rte_flow_item_eth.{src,dst}, I don't find a deprecation notice
>>>> about it in the history of the file doc/guides/rel_notes/deprecation.rst
>>>
>>> It took some time to find the deprecation notice, but I did find it
>>> in the end.  It's in the doc/guides/rel_notes/deprecation.rst, and
>>> it says:
>>>
>>> * ethdev: The flow API matching pattern structures, ``struct rte_flow_item_*``,
>>>   should start with relevant protocol header.
>>>   Some matching pattern structures implements this by duplicating protocol header
>>>   fields in the struct. To clarify the intention and to be sure protocol header
>>>   is intact, will replace those fields with relevant protocol header struct.
>>>   In v21.02 both individual protocol header fields and the protocol header struct
>>>   will be added as union, target is switch usage to the protocol header by time.
>>>   In v21.11 LTS, protocol header fields will be cleaned and only protocol header
>>>   struct will remain.
> 
> You're right, this is the general notice for rte_flow_item_*.
> 
>>>> This is what we have in the code:
>>>>     union {
>>>>         struct {
>>>>             /*
>>>>              * These fields are retained for compatibility.
>>>>              * Please switch to the new header field below.
>>>>              */
>>>>             struct rte_ether_addr dst; /**< Destination MAC. */
>>>>             struct rte_ether_addr src; /**< Source MAC. */
>>>>             rte_be16_t type; /**< EtherType or TPID. */
>>>>         };
>>>>         struct rte_ether_hdr hdr;
>>>>     };
>>>>
>>>> Do you think we should remove the old fields now?
>>>
>>> From the OVS perspective, we do not care much.  OVS is still using
>>> old fields, but it's fairly simple change that we can do while moving
>>> to a new version of DPDK.
>>>
>>> From the perspective of the API clarity, it's probably better to clean
>>> up these structures.
>>
>> There seems to be some outstanding work still though:
>>   https://patches.dpdk.org/project/dpdk/patch/20210312110745.31721-1-ivan.malov@oktetlabs.ru/#129161
> 
> I think nobody took care of it so far.
> I will send a patch to clean the easy ones,
> and I will follow up with Ori for a complete plan.
> 
> Thanks
> 
>