net/mlx5: fix modify action with tunnel decapsulation

[ upstream commit 9f71a29 ]

The driver splits the flow with sample action into two sub-flows,
sub prefix flow and sub suffix flow.

In the case of tunnel flow including a decap action, the driver should
translate the inner as outer for actions coming after the decap action.
In the case of flow splitting, the packet layers, used to detect the
attributes, are inherited from the prefix flow to the suffix flow but
the driver wrongly didn't handle the decap adjustment and the inner
layers didn't shift to the outer.

This patch adjusts the inherited layers in case of decap.

Fixes: 6e77151 ("net/mlx5: fix match information in meter")

Signed-off-by: Jiawei Wang <jiaweiw@nvidia.com>
Acked-by: Matan Azrad <matan@nvidia.com>

drivers/net/mlx5/mlx5_flow_dv.c

@@ -121,6 +121,13 @@ flow_dv_attr_init(const struct rte_flow_item *item, union flow_dv_attr *attr,
 	 * have the user defined items as the flow is split.
 	 */
 	if (layers) {
+		if (tunnel_decap) {
+			/*
+			 * If decap action before modify, it means the driver
+			 * should take the inner as outer for the modify actions.
+			 */
+			layers = ((layers >> 6) & MLX5_FLOW_LAYER_OUTER);
+		}
 		if (layers & MLX5_FLOW_LAYER_OUTER_L3_IPV4)
 			attr->ipv4 = 1;
 		else if (layers & MLX5_FLOW_LAYER_OUTER_L3_IPV6)