Subject: Re: [RFC bpf-next 0/7] bpf: netdev TX metadata

From: Toke Høiland-Jørgensen <[email-masked]>
Date: Thu, 15 Jun 2023 14:36:19 +0200

Alexei Starovoitov <[email-masked]> writes:

> On Wed, Jun 14, 2023 at 5:00 AM Toke Høiland-Jørgensen <[email-masked]> wrote:
>>
>> >>
>> >> It's probably going to work if each driver has a separate set of tx
>> >> fentry points, something like:
>> >>   {veth,mlx5,etc}_devtx_submit()
>> >>   {veth,mlx5,etc}_devtx_complete()
>>
>> I really don't get the opposition to exposing proper APIs; as a
>> dataplane developer I want to attach a program to an interface. The
>> kernel's role is to provide a consistent interface for this, not to
>> require users to become driver developers just to get at the required
>> details.
>
> Consistent interface can appear only when there is a consistency
> across nic manufacturers.
> I'm suggesting to experiment in the most unstable way and
> if/when the consistency is discovered then generalize.

That would be fine for new experimental HW features, but we're talking
about timestamps here: a feature that is already supported by multiple
drivers and for which the stack has a working abstraction. There's no
reason why we can't have that for the XDP path as well.

-Toke