doc: announce clarification of implicit filter by port

Transfer flow rules may be applied to traffic entering switch from
many sources. There are flow API pattern items which allow to specify
ingress port match criteria explicitly, but it is not documented
if ethdev port used to create flow rule adds any implicit match
criteria and how it coexists with explicit ones.

These aspects should be documented and drivers and applications
which use it in a different way must be fixed.

Signed-off-by: Andrew Rybchenko <andrew.rybchenko@oktetlabs.ru>
Acked-by: Ori Kam <orika@nvidia.com>
Acked-by: Ajit Khaparde <ajit.khaparde@broadcom.com>
Acked-by: Thomas Monjalon <thomas@monjalon.net>

diff --git a/doc/guides/rel_notes/deprecation.rst b/doc/guides/rel_notes/deprecation.rst
index 4799b642a7e2bb6e12ad3629933336b3bc6b0ff1..26051cc589b9e55fb9414a13591a5f81c80617a8 100644 (file)
--- a/doc/guides/rel_notes/deprecation.rst
+++ b/doc/guides/rel_notes/deprecation.rst
@@ -134,6 +134,11 @@ Deprecation Notices
   traffic direction to the represented entity or ethdev port itself
   in DPDK 21.11.
 
+* ethdev: Flow API documentation is unclear if ethdev port used to create
+  a flow rule adds any implicit match criteria in the case of transfer rules.
+  The semantics will be clarified in DPDK 21.11 and it will require fixes in
+  drivers and applications which interpret it in a different way.
+
 * ethdev: The flow API matching pattern structures, ``struct rte_flow_item_*``,
   should start with relevant protocol header.
   Some matching pattern structures implements this by duplicating protocol header