[dpdk-dev] [PATCH] net/mlx5: allow port start with zero Rx queues

[Dekel Peled <dekelp@mellanox.com>]

During port start, function mlx5_ctrl_flow_vlan() is called to create
default ingress flow rules.
For specific use-cases, a port can be used for Tx only.
In such case, number of Rx queues can be set to 0 to save resources,
hence the default ingress rules are irrelevant.

This patch modifies function mlx5_ctrl_flow_vlan() to avoid the
creation of the default ingress rules when number of Rx queues is 0.
It also includes update of validation functions for relevant actions,
mlx5_flow_validate_action_queue() and mlx5_flow_validate_action_rss(),
to prevent creation of flow rules with these actions when number of Rx
queues is 0.

Signed-off-by: Dekel Peled <dekelp@mellanox.com>
---
 drivers/net/mlx5/mlx5_flow.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/net/mlx5/mlx5_flow.c b/drivers/net/mlx5/mlx5_flow.c
index 0fd6ed5..f91aecd 100644
--- a/drivers/net/mlx5/mlx5_flow.c
+++ b/drivers/net/mlx5/mlx5_flow.c
@@ -846,6 +846,10 @@ uint32_t mlx5_flow_adjust_priority(struct rte_eth_dev *dev, int32_t priority,
 					  RTE_FLOW_ERROR_TYPE_ACTION, NULL,
 					  "can't have 2 fate actions in"
 					  " same flow");
+	if (!priv->rxqs_n)
+		return rte_flow_error_set(error, EINVAL,
+					  RTE_FLOW_ERROR_TYPE_ACTION_CONF,
+					  NULL, "No Rx queues configured");
 	if (queue->index >= priv->rxqs_n)
 		return rte_flow_error_set(error, EINVAL,
 					  RTE_FLOW_ERROR_TYPE_ACTION_CONF,
@@ -939,6 +943,10 @@ uint32_t mlx5_flow_adjust_priority(struct rte_eth_dev *dev, int32_t priority,
 					  &rss->types,
 					  "some RSS protocols are not"
 					  " supported");
+	if (!priv->rxqs_n)
+		return rte_flow_error_set(error, EINVAL,
+					  RTE_FLOW_ERROR_TYPE_ACTION_CONF,
+					  NULL, "No Rx queues configured");
 	for (i = 0; i != rss->queue_num; ++i) {
 		if (!(*priv->rxqs)[rss->queue[i]])
 			return rte_flow_error_set
@@ -2325,8 +2333,7 @@ struct rte_flow *
 	unsigned int i;
 
 	if (!priv->reta_idx_n || !priv->rxqs_n) {
-		rte_errno = EINVAL;
-		return -rte_errno;
+		return 0;
 	}
 	for (i = 0; i != priv->reta_idx_n; ++i)
 		queue[i] = (*priv->reta_idx)[i];
-- 
1.8.3.1