[dpdk-stable] [PATCH 17.11] net/mlx5: fix flow search on FDIR deletion

[Yongseok Koh]

When searching for a flow on FDIR deletion, the index for flow Rx queue
(flow->frxq[]) isn't referenced correclty by parser.layer. This is a bug in
mlx5_flow_convert(). This will have to be addresssed later. For now, this
workaround is enough.

Fixes: 37e900246c43 ("net/mlx5: fix flow director drop rule deletion crash")
Cc: Nelio Laranjeiro <nelio.laranjeiro at 6wind.com>
Cc: Shahaf Shuler <shahafs at mellanox.com>

Signed-off-by: Yongseok Koh <yskoh at mellanox.com>
---
 drivers/net/mlx5/mlx5_flow.c | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/drivers/net/mlx5/mlx5_flow.c b/drivers/net/mlx5/mlx5_flow.c
index 7e69f6aba..1822c2bdb 100644
--- a/drivers/net/mlx5/mlx5_flow.c
+++ b/drivers/net/mlx5/mlx5_flow.c
@@ -2960,10 +2960,21 @@ mlx5_fdir_filter_delete(struct rte_eth_dev *dev,
 		struct ibv_spec_header *flow_h;
 		void *flow_spec;
 		unsigned int specs_n;
-		unsigned int queue_id = parser.drop ? HASH_RXQ_ETH :
-						      parser.layer;
+		unsigned int queue_id;
 
-		attr = parser.queue[queue_id].ibv_attr;
+		/*
+		 * Search for a non-empty ibv_attr. There should be only one
+		 * because no RSS action is allowed for FDIR. This should have
+		 * been referenced directly by parser.layer but due to a bug in
+		 * mlx5_flow_convert() as of v17.11.4, parser.layer isn't
+		 * correct. This bug will have to be addressed later.
+		 */
+		for (queue_id = 0; queue_id != hash_rxq_init_n; ++queue_id) {
+			attr = parser.queue[queue_id].ibv_attr;
+			if (attr)
+				break;
+		}
+		assert(!parser.drop || queue_id == HASH_RXQ_ETH);
 		flow_attr = flow->frxq[queue_id].ibv_attr;
 		/* Compare first the attributes. */
 		if (!flow_attr ||
-- 
2.11.0