[xdp-hints] Interest in TX-side XDP metadata hints from Intel (+ Red Hat)

[Jesper Dangaard Brouer <hawk@kernel.org>]

Hi Stanislav,

Sharing that Intel (+Red Hat) have an interest in getting XDP metadata
hints working on smaller devices used for "Edge Controls for Industrial"
(ECI)[1].

What are your plans for your patchset[2] ?

My suggestion (to Intel) is that we implement the TX-timestamp (plus
LaunchTime) on top of Stanslav's patches[2].  For drivers igc+igb+stmmac
which I think will cover the tests[3] need by Arun/Costin (?). And then
post it upstream for review.

The Intel test tool[3] isn't open, but it is an AF_XDP based Real-Time
Compute Performance (RTCP) application that show-case a real-time
control loop application.  The current code uses out-of-tree[4] "TXTIME"
LaunchTime feature, that want not upstreamed.

Lets us instead implement a proper TX LaunchTime feature on top of [2].

--Jesper
cc. XDP-hints ML as anyone is free to code this up, code help here[5]


[1] https://eci.intel.com/
[2] https://lore.kernel.org/all/20230809165418.2831456-1-sdf@google.com/
[3] https://github.com/OTCShare2/rtcp-xdp
[4] https://lore.kernel.org/all/20210621230635.3a83851c@carbon/
[5] 
https://github.com/xdp-project/xdp-project/blob/master/areas/tsn/code01_follow_qdisc_TSN_offload.org#tx-time-to-hardware-driver-igc