RE: [PATCH v2] app/test-pmd: add generic PROG action parser support

[Konstantin Ananyev <konstantin.ananyev@huawei.com>]

> >
> > This looks like a third attempt to parse text into rte_flow.
> > Not sure how this fits in and why it would be useful?
> 
> Thanks for the feedback.
> I wanted to clarify the intent of this patch. The backend support for the PROG
> action already exists in the PMD. This patch is focused on adding the
> corresponding frontend (testpmd) parser support so that users can configure
> and exercise this functionality via CLI.
> The motivation here is to enable configuration of programmable actions that are
> already supported in the backend but cannot currently be invoked through
> testpmd. With this addition, new actions that are exposed through PROG can be
> configured using the flow command interface.

For my own curiosity: how user can define his own PROG action?
Is it supposed to be programmed and uplodaded to the NIC by some external tool (P4 compiler)?
Or does it refer to the set of some predefined functions that given firmware supports?
Or ... ?
Sorry for probably naive questions, but I found is nearly zero information inside DPDK docs about
how PROG action supposed to work.
Thanks
Konstantin