[dpdk-dev] [PATCH] doc: announce ABI change for librte_port

[Cristian Dumitrescu <cristian.dumitrescu@intel.com>]

Signed-off-by: Cristian Dumitrescu <cristian.dumitrescu@intel.com>
---
 doc/guides/rel_notes/abi.rst |   12 ++++++++++++
 1 files changed, 12 insertions(+), 0 deletions(-)

diff --git a/doc/guides/rel_notes/abi.rst b/doc/guides/rel_notes/abi.rst
index 9e98d62..271e08e 100644
--- a/doc/guides/rel_notes/abi.rst
+++ b/doc/guides/rel_notes/abi.rst
@@ -34,3 +34,15 @@ Deprecation Notices
   creates a dummy/empty malloc library to fulfill binaries with dynamic linking
   dependencies on librte_malloc.so. Such dummy library will not be created from
   release 2.2 so binaries will need to be rebuilt.
+
+* librte_port (rte_port.h): Macros to access the packet meta-data stored within
+  the packet buffer will be adjusted to cover the packet mbuf structure as well,
+  as currently they are able to access any packet buffer location except the
+  packet mbuf structure. The consequence is that applications currently using
+  these macros will have to adjust the value of the offset parameter of these
+  macros by increasing it with sizeof(struc rte_mbuf). The affected macros are:
+  RTE_MBUF_METADATA_UINT<8, 16, 32, 64>_PTR and
+  RTE_MBUF_METADATA_UINT<8, 16, 32, 64>. In terms of code changes, most likely
+  only the definition of RTE_MBUF_METADATA_UINT8_PTR macro will be changed from
+  ``(&((uint8_t *) &(mbuf)[1])[offset])`` to
+  ``(&((uint8_t *) (mbuf))[offset])``.
-- 
1.7.4.1