[dpdk-dev] [PATCH v2] net/mlx5: fix push VLAN action wrongly use item info

[Xiaoyu Min]

Currently when PMD create push VLAN action it need to provide VID to HW
and PMD get VID value from item VLAN in pattern if there is no
of_set_vlan_vid action following.

When user create rule like [1], which has of_set_vlan_vid action
before of_push_vlan, the intention is to modify VID on existing VLAN
header and push a new VLAN header with VID _inherit_ from the previous
of_set_vlan_vid.

Currently the above is not covered by PMD, PMD always fetch the VLAN
information from item for of_push_vlan action.

Fix it by only fetch VLAN information from item when there is no
previous of_set_vlan_vid action.

[1]: testpmd> flow create 2 ingress transfer group 1 priority 3 pattern
                eth / vlan vid is 2731 / ipv4 / end actions
		of_set_vlan_vid vlan_vid 3209 / of_push_vlan ethertype
		0x88A8 / port_id id 1 / end

Fixes: b8c0372bc5ac ("net/mlx5: fix set VLAN ID/PCP in new header")
Cc: stable at dpdk.org

Signed-off-by: Xiaoyu Min <jackmin at mellanox.com>
Reviewed-by: Dekel Peled <dekelp at mellanox.com>
Acked-by: Viacheslav Ovsiienko <viacheslavo at mellanox.com>
---
v2:
  - rebased
  - added Acked-by tag

 drivers/net/mlx5/mlx5_flow_dv.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/net/mlx5/mlx5_flow_dv.c b/drivers/net/mlx5/mlx5_flow_dv.c
index 18ea577f8c..106d0b9461 100644
--- a/drivers/net/mlx5/mlx5_flow_dv.c
+++ b/drivers/net/mlx5/mlx5_flow_dv.c
@@ -7511,7 +7511,9 @@ __flow_dv_translate(struct rte_eth_dev *dev,
 			action_flags |= MLX5_FLOW_ACTION_OF_POP_VLAN;
 			break;
 		case RTE_FLOW_ACTION_TYPE_OF_PUSH_VLAN:
-			flow_dev_get_vlan_info_from_items(items, &vlan);
+			if (!(action_flags &
+			      MLX5_FLOW_ACTION_OF_SET_VLAN_VID))
+				flow_dev_get_vlan_info_from_items(items, &vlan);
 			vlan.eth_proto = rte_be_to_cpu_16
 			     ((((const struct rte_flow_action_of_push_vlan *)
 						   actions->conf)->ethertype));
-- 
2.26.0