[dpdk-dev] [PATCH] net/mlx5: fix flow RSS configuration

[Nelio Laranjeiro <nelio.laranjeiro@6wind.com>]

An RSS configuration without a key is valid according to the
rte_eth_rss_conf API definition.

Fixes: 8086cf08b2f0 ("net/mlx5: handle RSS hash configuration in RSS flow")

Cc: stable@dpdk.org
Reported-by: Yuanhan Liu <yliu@fridaylinux.org>
Signed-off-by: Nelio Laranjeiro <nelio.laranjeiro@6wind.com>
---
 drivers/net/mlx5/mlx5_flow.c | 29 +++++++++++++++++------------
 1 file changed, 17 insertions(+), 12 deletions(-)

diff --git a/drivers/net/mlx5/mlx5_flow.c b/drivers/net/mlx5/mlx5_flow.c
index ea90556d0..fd6f96083 100644
--- a/drivers/net/mlx5/mlx5_flow.c
+++ b/drivers/net/mlx5/mlx5_flow.c
@@ -514,7 +514,8 @@ mlx5_flow_item_validate(const struct rte_flow_item *item,
 }
 
 /**
- * Copy the RSS configuration from the user ones.
+ * Copy the RSS configuration from the user ones, of the rss_conf is null,
+ * uses the driver one.
  *
  * @param priv
  *   Pointer to private structure.
@@ -531,21 +532,25 @@ priv_flow_convert_rss_conf(struct priv *priv,
 			   struct mlx5_flow_parse *parser,
 			   const struct rte_eth_rss_conf *rss_conf)
 {
-	const struct rte_eth_rss_conf *rss;
-
+	/*
+	 * This function is also called at the beginning of
+	 * priv_flow_convert_actions() to initialise the parser with the
+	 * device default RSS configuration.
+	 */
+	(void)priv;
 	if (rss_conf) {
 		if (rss_conf->rss_hf & MLX5_RSS_HF_MASK)
 			return EINVAL;
-		rss = rss_conf;
-	} else {
-		rss = &priv->rss_conf;
+		if (rss_conf->rss_key_len != 40)
+			return EINVAL;
+		if (rss_conf->rss_key_len && rss_conf->rss_key) {
+			parser->rss_conf.rss_key_len = rss_conf->rss_key_len;
+			memcpy(parser->rss_key, rss_conf->rss_key,
+			       rss_conf->rss_key_len);
+			parser->rss_conf.rss_key = parser->rss_key;
+		}
+		parser->rss_conf.rss_hf = rss_conf->rss_hf;
 	}
-	if (rss->rss_key_len > 40)
-		return EINVAL;
-	parser->rss_conf.rss_key_len = rss->rss_key_len;
-	parser->rss_conf.rss_hf = rss->rss_hf;
-	memcpy(parser->rss_key, rss->rss_key, rss->rss_key_len);
-	parser->rss_conf.rss_key = parser->rss_key;
 	return 0;
 }
 
-- 
2.11.0