Re: [dpdk-dev] [PATCH v3 1/5] ethdev: add API to negotiate delivery of Rx meta data

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

On 10/4/21 2:39 PM, Ivan Malov wrote:
> On 04/10/2021 09:56, Ori Kam wrote:
>>> On 04/10/2021 00:04, Ori Kam wrote:
>>>> I understand that you are only talking about enabling the action,
>>>> meaning to let the PMD know that at some point there will be a rule
>>>> that will use the mark action for example.
>>>> Is my understanding correct?
>>>
>>> Not really. The causal relationships are as follows. The application
>>> comes to
>>> realise that it will need to use, say, action MARK in flows.
>>> This, in turn, means that, in order to be able to actually see the
>>> mark in
>>> received packets, the application needs to ensure that a) the NIC
>>> will be able
>>> to deliver the mark to the PMD and b) that the PMD will be able to
>>> deliver
>>> the mark to the application. In particular, in the case of Rx mark,
>>> (b) doesn't
>>> need to be negotiated = field "mark" is anyway provisioned in the mbuf
>>> structure, so no need to enable it. But (a) needs to be negotiated.
>>> Hence this
>>> API.
>>>
>> Please see my above comment I think we both agree.
> 
> Agree to have the 4-th flag in the new API to cover this "custom / raw
> metdata" delivery? Personally, I tend to agree, but maybe Andrew can
> express his opinion, too.

Of course, it could be added, but we're not going to support it
in net/sfc. So, I think the flag should be added when a PMD
will going to support it (e.g. net/mlx5).