[dpdk-dev] [PATCH v2] net/mlx5: fix inlining segmented TSO packet

[Yongseok Koh <yskoh@mellanox.com>]

When a multi-segmented packet is inlined, data can be further inlined even
after the first segment. In case of TSO packet, extra inline data after TSO
header should be carried by an inline DSEG which has 4B inline header
recording the length of the inline data. If more than one segment is
inlined, the length doesn't count from the second segment. This will cause
a fault in HW and CQE will have an error, which is ignored by PMD.

Fixes: f895536be4fa ("net/mlx5: enable inlining data from multiple segments")
Cc: stable@dpdk.org

Signed-off-by: Xueming Li <xuemingl@mellanox.com>
Signed-off-by: Yongseok Koh <yskoh@mellanox.com>
---

v2:
* replace unnecessary check of 'inl' with assert().
* add "Signed-off-by: Xueming Li".

 drivers/net/mlx5/mlx5_rxtx.c | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/drivers/net/mlx5/mlx5_rxtx.c b/drivers/net/mlx5/mlx5_rxtx.c
index d960a73d5..a2b373e21 100644
--- a/drivers/net/mlx5/mlx5_rxtx.c
+++ b/drivers/net/mlx5/mlx5_rxtx.c
@@ -645,7 +645,8 @@ mlx5_tx_burst(void *dpdk_txq, struct rte_mbuf **pkts, uint16_t pkts_n)
 				if (unlikely(max_wqe < n))
 					break;
 				max_wqe -= n;
-				if (tso && !inl) {
+				if (tso) {
+					assert(inl == 0);
 					inl = rte_cpu_to_be_32(copy_b |
 							       MLX5_INLINE_SEG);
 					rte_memcpy((void *)raw,
@@ -680,8 +681,17 @@ mlx5_tx_burst(void *dpdk_txq, struct rte_mbuf **pkts, uint16_t pkts_n)
 			} else if (!segs_n) {
 				goto next_pkt;
 			} else {
-				raw += copy_b;
-				inline_room -= copy_b;
+				/*
+				 * Further inline the next segment only for
+				 * non-TSO packets.
+				 */
+				if (!tso) {
+					raw += copy_b;
+					inline_room -= copy_b;
+				} else {
+					inline_room = 0;
+				}
+				/* Move to the next segment. */
 				--segs_n;
 				buf = buf->next;
 				assert(buf);
-- 
2.11.0