net/mlx5: fix VLAN PCP item calculation

The VLAN 16 bits tci field contains both values of PCP and VID. When
extracting any one of them - it is required not to affect the other one.
Previous to this commit in routine flow_dev_get_vlan_info_from_items()
we calculated the PCP as follows:
    (1) vlan->vlan_tci &= MLX5DV_FLOW_VLAN_PCP_MASK;
    (2) vlan->vlan_tci |= <3 bits value of PCP>
In line (1) we should have used the negated mask ('~' operator) such
that only the PCP bits will be nullified before ORing them with the
updated PCP value.

Fixes: 9aee7a8418d4 ("net/mlx5: support push flow action on VLAN header")
Cc: stable@dpdk.org
Signed-off-by: Ophir Munk <ophirmu@mellanox.com>
Acked-by: Viacheslav Ovsiienko <viacheslavo@mellanox.com>

diff --git a/drivers/net/mlx5/mlx5_flow_dv.c b/drivers/net/mlx5/mlx5_flow_dv.c
index 06592b5..2414a97 100644 (file)
--- a/drivers/net/mlx5/mlx5_flow_dv.c
+++ b/drivers/net/mlx5/mlx5_flow_dv.c
@@ -1771,7 +1771,7 @@ flow_dev_get_vlan_info_from_items(const struct rte_flow_item *items,
                /* Only full match values are accepted */
                if ((vlan_m->tci & MLX5DV_FLOW_VLAN_PCP_MASK_BE) ==
                     MLX5DV_FLOW_VLAN_PCP_MASK_BE) {
-                       vlan->vlan_tci &= MLX5DV_FLOW_VLAN_PCP_MASK;
+                       vlan->vlan_tci &= ~MLX5DV_FLOW_VLAN_PCP_MASK;
                        vlan->vlan_tci |=
                                rte_be_to_cpu_16(vlan_v->tci &
                                                 MLX5DV_FLOW_VLAN_PCP_MASK_BE);