[dpdk-stable] [PATCH] net/mlx5: fix vectorized Rx burst error handling

[Dekel Peled <dekelp@mellanox.com>]

In the process of recovery from error CQE, when using vectorized Rx
burst, the initialization of data length in mbufs was not done.
As a result the wrong length was left written in mbuf, causing
memory overwrite or wrong error report.

This patch fixes the initialization of mbuf data length during
recovery from error CQE, when using vectorized Rx burst,

Fixes: 88c0733535d6 ("net/mlx5: extend Rx completion with error handling")
Cc: stable@dpdk.org

Signed-off-by: Dekel Peled <dekelp@mellanox.com>
---
 drivers/net/mlx5/mlx5_rxtx.c | 19 +++++++++++++++----
 drivers/net/mlx5/mlx5_rxtx.h |  3 +--
 2 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/drivers/net/mlx5/mlx5_rxtx.c b/drivers/net/mlx5/mlx5_rxtx.c
index f540977..10d0ca1 100644
--- a/drivers/net/mlx5/mlx5_rxtx.c
+++ b/drivers/net/mlx5/mlx5_rxtx.c
@@ -940,14 +940,15 @@ enum mlx5_txcmp_code {
  *
  * @param[in] rxq
  *   Pointer to RX queue structure.
- * @param[in] mbuf_prepare
- *   Whether to prepare mbufs for the RQ.
+ * @param[in] vec
+ *   1 when called from vectorized Rx burst, need to prepare mbufs for the RQ.
+ *   0 when called from non-vectorized Rx burst.
  *
  * @return
  *   -1 in case of recovery error, otherwise the CQE status.
  */
 int
-mlx5_rx_err_handle(struct mlx5_rxq_data *rxq, uint8_t mbuf_prepare)
+mlx5_rx_err_handle(struct mlx5_rxq_data *rxq, uint8_t vec)
 {
 	const uint16_t cqe_n = 1 << rxq->cqe_n;
 	const uint16_t cqe_mask = cqe_n - 1;
@@ -1014,7 +1015,7 @@ enum mlx5_txcmp_code {
 			if (mlx5_queue_state_modify(ETH_DEV(rxq_ctrl->priv),
 						    &sm))
 				return -1;
-			if (mbuf_prepare) {
+			if (vec) {
 				const uint16_t q_mask = wqe_n - 1;
 				uint16_t elt_idx;
 				struct rte_mbuf **elt;
@@ -1038,6 +1039,16 @@ enum mlx5_txcmp_code {
 						return -1;
 					}
 				}
+				for (i = 0; i < (int)wqe_n; ++i) {
+					elt = &(*rxq->elts)[i];
+					DATA_LEN(*elt) =
+						(uint16_t)((*elt)->buf_len -
+						rte_pktmbuf_headroom(*elt));
+				}
+				/* Padding with a fake mbuf for vec Rx. */
+				for (i = 0; i < MLX5_VPMD_DESCS_PER_LOOP; ++i)
+					(*rxq->elts)[wqe_n + i] =
+								&rxq->fake_mbuf;
 			}
 			mlx5_rxq_initialize(rxq);
 			rxq->err_state = MLX5_RXQ_ERR_STATE_NO_ERROR;
diff --git a/drivers/net/mlx5/mlx5_rxtx.h b/drivers/net/mlx5/mlx5_rxtx.h
index 4f73d91..4bb28a4 100644
--- a/drivers/net/mlx5/mlx5_rxtx.h
+++ b/drivers/net/mlx5/mlx5_rxtx.h
@@ -406,8 +406,7 @@ struct mlx5_txq_ctrl *mlx5_txq_new(struct rte_eth_dev *dev, uint16_t idx,
 				 volatile struct mlx5_err_cqe *err_cqe);
 uint16_t mlx5_rx_burst(void *dpdk_rxq, struct rte_mbuf **pkts, uint16_t pkts_n);
 void mlx5_rxq_initialize(struct mlx5_rxq_data *rxq);
-__rte_noinline int mlx5_rx_err_handle(struct mlx5_rxq_data *rxq,
-				      uint8_t mbuf_prepare);
+__rte_noinline int mlx5_rx_err_handle(struct mlx5_rxq_data *rxq, uint8_t vec);
 void mlx5_mprq_buf_free_cb(void *addr, void *opaque);
 void mlx5_mprq_buf_free(struct mlx5_mprq_buf *buf);
 uint16_t mlx5_rx_burst_mprq(void *dpdk_rxq, struct rte_mbuf **pkts,
-- 
1.8.3.1