[dpdk-dev] [PATCH v2] net/mlx5: setup RSS regardless of queue count

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

From: Dahir Osman <dahir.osman@windriver.com>

In some environments it is desirable to have the NIC perform RSS
normally on the packet regardless of the number of queues configured.
The RSS hash result that is stored in the mbuf can then be used by
the application to make decisions about how to distribute workloads
to threads, secondary processes, or even virtual machines if the
application is a virtual switch.  This change to the mlx5 driver
aligns with how other drivers in the Intel family work.

Signed-off-by: Allain Legacy <allain.legacy@windriver.com>
Signed-off-by: Nelio Laranjeiro <nelio.laranjeiro@6wind.com>
---
 drivers/net/mlx5/mlx5_flow.c |  2 +-
 drivers/net/mlx5/mlx5_rss.c  | 10 ++++++++++
 drivers/net/mlx5/mlx5_rxq.c  |  3 ++-
 3 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/drivers/net/mlx5/mlx5_flow.c b/drivers/net/mlx5/mlx5_flow.c
index 3eecdc604..49600e174 100644
--- a/drivers/net/mlx5/mlx5_flow.c
+++ b/drivers/net/mlx5/mlx5_flow.c
@@ -909,7 +909,7 @@ mlx5_flow_convert_finalise(struct mlx5_flow_parse *parser)
 	unsigned int i;
 
 	/* Remove any other flow not matching the pattern. */
-	if (parser->queues_n == 1) {
+	if (parser->queues_n == 1 && !parser->rss_conf.rss_hf) {
 		for (i = 0; i != hash_rxq_init_n; ++i) {
 			if (i == HASH_RXQ_ETH)
 				continue;
diff --git a/drivers/net/mlx5/mlx5_rss.c b/drivers/net/mlx5/mlx5_rss.c
index 5ac650163..c490854e1 100644
--- a/drivers/net/mlx5/mlx5_rss.c
+++ b/drivers/net/mlx5/mlx5_rss.c
@@ -42,6 +42,8 @@ mlx5_rss_hash_update(struct rte_eth_dev *dev,
 		     struct rte_eth_rss_conf *rss_conf)
 {
 	struct priv *priv = dev->data->dev_private;
+	unsigned int i;
+	unsigned int idx;
 
 	if (rss_conf->rss_hf & MLX5_RSS_HF_MASK) {
 		rte_errno = EINVAL;
@@ -59,6 +61,14 @@ mlx5_rss_hash_update(struct rte_eth_dev *dev,
 		priv->rss_conf.rss_key_len = rss_conf->rss_key_len;
 	}
 	priv->rss_conf.rss_hf = rss_conf->rss_hf;
+	/* Enable the RSS hash in all Rx queues. */
+	for (i = 0, idx = 0; idx != priv->rxqs_n; ++i) {
+		if (!(*priv->rxqs)[i])
+			continue;
+		(*priv->rxqs)[i]->rss_hash = !!rss_conf->rss_hf &&
+			!!(dev->data->dev_conf.rxmode.mq_mode & ETH_MQ_RX_RSS);
+		++idx;
+	}
 	return 0;
 }
 
diff --git a/drivers/net/mlx5/mlx5_rxq.c b/drivers/net/mlx5/mlx5_rxq.c
index 56b2d19f2..1b4570586 100644
--- a/drivers/net/mlx5/mlx5_rxq.c
+++ b/drivers/net/mlx5/mlx5_rxq.c
@@ -1070,7 +1070,8 @@ mlx5_rxq_new(struct rte_eth_dev *dev, uint16_t idx, uint16_t desc,
 		tmpl->rxq.crc_present ? "disabled" : "enabled",
 		tmpl->rxq.crc_present << 2);
 	/* Save port ID. */
-	tmpl->rxq.rss_hash = priv->rxqs_n > 1;
+	tmpl->rxq.rss_hash = !!priv->rss_conf.rss_hf &&
+		(!!(dev->data->dev_conf.rxmode.mq_mode & ETH_MQ_RX_RSS));
 	tmpl->rxq.port_id = dev->data->port_id;
 	tmpl->priv = priv;
 	tmpl->rxq.mp = mp;
-- 
2.11.0