[PATCH] common/mlx5: fix MPRQ mempool registration

[Dmitry Kozlyuk]

Mempool registration code had a wrong assumption
that it is always dealing with packet mempools
and always called rte_pktmbuf_priv_flags(),
which returned a random value for different types of mempools.
In particular, it could consider MPRQ mempools
as having externally pinned buffers, which is wrong.
Packet mempools cannot be reliably recognized,
but it is sufficient to check that the mempool is not a packet one,
so it cannot have externally pinned buffers.
Compare mempool private data size to that of packet mempools to check.

Fixes: 690b2a88c2f7 ("common/mlx5: add mempool registration facilities")
Fixes: fec28ca0e3a9 ("net/mlx5: support mempool registration")

Signed-off-by: Dmitry Kozlyuk <dkozlyuk at nvidia.com>
---
 drivers/common/mlx5/mlx5_common.c    |  3 +--
 drivers/common/mlx5/mlx5_common_mr.c |  2 +-
 drivers/common/mlx5/mlx5_common_mr.h | 10 ++++++++++
 drivers/net/mlx5/mlx5_trigger.c      |  5 +++--
 4 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/drivers/common/mlx5/mlx5_common.c b/drivers/common/mlx5/mlx5_common.c
index b9ed5ee676..66c2c08b7d 100644
--- a/drivers/common/mlx5/mlx5_common.c
+++ b/drivers/common/mlx5/mlx5_common.c
@@ -390,8 +390,7 @@ mlx5_dev_mempool_event_cb(enum rte_mempool_event event, struct rte_mempool *mp,
 			  void *arg)
 {
 	struct mlx5_common_device *cdev = arg;
-	bool extmem = rte_pktmbuf_priv_flags(mp) &
-		      RTE_PKTMBUF_POOL_F_PINNED_EXT_BUF;
+	bool extmem = mlx5_mempool_is_extmem(mp);
 
 	switch (event) {
 	case RTE_MEMPOOL_EVENT_READY:
diff --git a/drivers/common/mlx5/mlx5_common_mr.c b/drivers/common/mlx5/mlx5_common_mr.c
index 49feea4474..69fae88fb0 100644
--- a/drivers/common/mlx5/mlx5_common_mr.c
+++ b/drivers/common/mlx5/mlx5_common_mr.c
@@ -1414,7 +1414,7 @@ mlx5_get_mempool_ranges(struct rte_mempool *mp, struct mlx5_range **out,
 	int ret;
 
 	/* Collect the pool underlying memory. */
-	ret = (rte_pktmbuf_priv_flags(mp) & RTE_PKTMBUF_POOL_F_PINNED_EXT_BUF) ?
+	ret = mlx5_mempool_is_extmem(mp) ?
 	      mlx5_mempool_get_extmem(mp, &chunks, &chunks_n) :
 	      mlx5_mempool_get_chunks(mp, &chunks, &chunks_n);
 	if (ret < 0)
diff --git a/drivers/common/mlx5/mlx5_common_mr.h b/drivers/common/mlx5/mlx5_common_mr.h
index dc7ddc3513..442b9d4694 100644
--- a/drivers/common/mlx5/mlx5_common_mr.h
+++ b/drivers/common/mlx5/mlx5_common_mr.h
@@ -263,4 +263,14 @@ int
 mlx5_mr_mempool_unregister(struct mlx5_common_device *cdev,
 			   struct rte_mempool *mp);
 
+/** Check if @p mp has buffers pinned in external memory. */
+static inline bool
+mlx5_mempool_is_extmem(struct rte_mempool *mp)
+{
+	return (mp->private_data_size ==
+		sizeof(struct rte_pktmbuf_pool_private)) &&
+	       (mp->elt_size >= sizeof(struct rte_mbuf)) &&
+	       (rte_pktmbuf_priv_flags(mp) & RTE_PKTMBUF_POOL_F_PINNED_EXT_BUF);
+}
+
 #endif /* RTE_PMD_MLX5_COMMON_MR_H_ */
diff --git a/drivers/net/mlx5/mlx5_trigger.c b/drivers/net/mlx5/mlx5_trigger.c
index 1952d68444..4440a765d9 100644
--- a/drivers/net/mlx5/mlx5_trigger.c
+++ b/drivers/net/mlx5/mlx5_trigger.c
@@ -149,13 +149,14 @@ mlx5_rxq_mempool_register(struct mlx5_rxq_ctrl *rxq_ctrl)
 		uint32_t flags;
 
 		mp = rxq_ctrl->rxq.rxseg[s].mp;
-		flags = rte_pktmbuf_priv_flags(mp);
+		flags = mp != rxq_ctrl->rxq.mprq_mp ?
+			rte_pktmbuf_priv_flags(mp) : 0;
 		ret = mlx5_mr_mempool_register(rxq_ctrl->sh->cdev, mp);
 		if (ret < 0 && rte_errno != EEXIST)
 			return ret;
 		if ((flags & RTE_PKTMBUF_POOL_F_PINNED_EXT_BUF) == 0)
 			rte_mempool_mem_iter(mp, mlx5_rxq_mempool_register_cb,
-					&rxq_ctrl->rxq);
+					     &rxq_ctrl->rxq);
 	}
 	return 0;
 }
-- 
2.25.1