Re: [dpdk-dev] [PATCH v3 0/5] A means to negotiate delivery of Rx meta data

[Thomas Monjalon <thomas@monjalon.net>]

23/09/2021 13:20, Ivan Malov:
> In 2019, commit [1] announced changes in DEV_RX_OFFLOAD namespace
> intending to add new flags, RSS_HASH and FLOW_MARK. Since then,
> only the former has been added. The problem hasn't been solved.
> Applications still assume that no efforts are needed to enable
> flow mark and similar meta data delivery.
> 
> The team behind net/sfc driver has to take over the efforts since
> the problem has started impacting us. Riverhead, a cutting edge
> Xilinx smart NIC family, has two Rx prefix types. Rx meta data
> is available only from long Rx prefix. Switching between the
> prefix formats can't happen in started state. Hence, we run
> into the same problem which [1] was aiming to solve.

Sorry I don't understand what is Rx prefix?

> Rx meta data (mark, flag, tunnel ID) delivery is not an offload
> on its own since the corresponding flows must be active to set
> the data in the first place. Hence, adding offload flags
> similar to RSS_HASH is not a good idea.

What means "active" here?

> Patch [1/5] of this series adds a generic API to let applications
> negotiate delivery of Rx meta data during initialisation period.
> This way, an application knows right from the start which parts
> of Rx meta data won't be delivered. Hence, no necessity to try
> inserting flows requesting such data and handle the failures.

Sorry I don't understand the problem you want to solve.
And sorry for not noticing earlier.