[dpdk-dev] [PATCH v2 1/3] security: enforce semantics for Tx inline processing

[Nithin Dabilpuram <ndabilpuram@marvell.com>]

Not all net PMD's/HW can parse packet and identify L2 header and
L3 header locations on Tx. This is inline with other Tx offloads
requirements such as L3 checksum, L4 checksum offload, etc,
where mbuf.l2_len, mbuf.l3_len etc, needs to be set for HW to be
able to generate checksum. Since Inline IPSec is also such a Tx
offload, some PMD's at least need mbuf.l2_len to be valid to
find L3 header and perform Outbound IPSec processing.

Hence, this patch updates documentation to enforce setting
mbuf.l2_len while setting PKT_TX_SEC_OFFLOAD in mbuf.ol_flags
for Inline IPSec Crypto / Protocol offload processing to
work on Tx.

Signed-off-by: Nithin Dabilpuram <ndabilpuram@marvell.com>
---
 doc/guides/nics/features.rst | 2 ++
 lib/mbuf/rte_mbuf_core.h     | 2 ++
 2 files changed, 4 insertions(+)

diff --git a/doc/guides/nics/features.rst b/doc/guides/nics/features.rst
index a96e12d..4fce8cd 100644
--- a/doc/guides/nics/features.rst
+++ b/doc/guides/nics/features.rst
@@ -430,6 +430,7 @@ of protocol operations. See Security library and PMD documentation for more deta
 
 * **[uses]       rte_eth_rxconf,rte_eth_rxmode**: ``offloads:DEV_RX_OFFLOAD_SECURITY``,
 * **[uses]       rte_eth_txconf,rte_eth_txmode**: ``offloads:DEV_TX_OFFLOAD_SECURITY``.
+* **[uses]       mbuf**: ``mbuf.l2_len``.
 * **[implements] rte_security_ops**: ``session_create``, ``session_update``,
   ``session_stats_get``, ``session_destroy``, ``set_pkt_metadata``, ``capabilities_get``.
 * **[provides] rte_eth_dev_info**: ``rx_offload_capa,rx_queue_offload_capa:DEV_RX_OFFLOAD_SECURITY``,
@@ -451,6 +452,7 @@ protocol operations. See security library and PMD documentation for more details
 
 * **[uses]       rte_eth_rxconf,rte_eth_rxmode**: ``offloads:DEV_RX_OFFLOAD_SECURITY``,
 * **[uses]       rte_eth_txconf,rte_eth_txmode**: ``offloads:DEV_TX_OFFLOAD_SECURITY``.
+* **[uses]       mbuf**: ``mbuf.l2_len``.
 * **[implements] rte_security_ops**: ``session_create``, ``session_update``,
   ``session_stats_get``, ``session_destroy``, ``set_pkt_metadata``, ``get_userdata``,
   ``capabilities_get``.
diff --git a/lib/mbuf/rte_mbuf_core.h b/lib/mbuf/rte_mbuf_core.h
index bb38d7f..9d8e3dd 100644
--- a/lib/mbuf/rte_mbuf_core.h
+++ b/lib/mbuf/rte_mbuf_core.h
@@ -228,6 +228,8 @@ extern "C" {
 
 /**
  * Request security offload processing on the TX packet.
+ * To use Tx security offload, the user needs to fill l2_len in mbuf
+ * indicating L2 header size and where L3 header starts.
  */
 #define PKT_TX_SEC_OFFLOAD	(1ULL << 43)
 
-- 
2.8.4