net/mlx5: fix partial inline of fine grain packets

Assuming a user tried to send multi-segment packets, with
RTE_PMD_MLX5_FINE_GRANULARITY_INLINE flag set, using a device with
minimum inlining requirements (such as ConnectX-4 Lx or when user
specified them explicitly), sending such packets caused segfault.
Segfault was caused by failed invariants in
mlx5_tx_packet_multi_inline function.

This patch introduces a logic for multi-segment packets, with
RTE_PMD_MLX5_FINE_GRANULARITY_INLINE flag set, to omit mbuf scanning for
filling inline buffer and inline only minimal amount of data required.

Fixes: ec837ad0fc7c ("net/mlx5: fix multi-segment inline for the first segments")
Cc: stable@dpdk.org
Signed-off-by: Dariusz Sosnowski <dsosnowski@nvidia.com>
Acked-by: Viacheslav Ovsiienko <viacheslavo@nvidia.com>

diff --git a/drivers/net/mlx5/mlx5_tx.h b/drivers/net/mlx5/mlx5_tx.h
index ad13b5e..bc62998 100644 (file)
--- a/drivers/net/mlx5/mlx5_tx.h
+++ b/drivers/net/mlx5/mlx5_tx.h
@@ -1933,7 +1933,7 @@ mlx5_tx_packet_multi_inline(struct mlx5_txq_data *__rte_restrict txq,
                        MLX5_ASSERT(txq->inlen_mode >=
                                    MLX5_ESEG_MIN_INLINE_SIZE);
                        MLX5_ASSERT(txq->inlen_mode <= txq->inlen_send);
-                       inlen = txq->inlen_mode;
+                       inlen = RTE_MIN(txq->inlen_mode, inlen);
                } else if (vlan && !txq->vlan_en) {
                        /*
                         * VLAN insertion is requested and hardware does not
@@ -1946,6 +1946,8 @@ mlx5_tx_packet_multi_inline(struct mlx5_txq_data *__rte_restrict txq,
                } else {
                        goto do_first;
                }
+               if (mbuf->ol_flags & RTE_MBUF_F_TX_DYNF_NOINLINE)
+                       goto do_build;
                /*
                 * Now we know the minimal amount of data is requested
                 * to inline. Check whether we should inline the buffers
@@ -1978,6 +1980,8 @@ do_first:
                                mbuf = NEXT(mbuf);
                                /* There should be not end of packet. */
                                MLX5_ASSERT(mbuf);
+                               if (mbuf->ol_flags & RTE_MBUF_F_TX_DYNF_NOINLINE)
+                                       break;
                                nxlen = inlen + rte_pktmbuf_data_len(mbuf);
                        } while (unlikely(nxlen < txq->inlen_send));
                }
@@ -2005,6 +2009,7 @@ do_align:
         * Estimate the number of Data Segments conservatively,
         * supposing no any mbufs is being freed during inlining.
         */
+do_build:
        MLX5_ASSERT(inlen <= txq->inlen_send);
        ds = NB_SEGS(loc->mbuf) + 2 + (inlen -
                                       MLX5_ESEG_MIN_INLINE_SIZE +