From: Vlad Buslov <vladbu@nvidia.com>
Date: Mon, 28 Mar 2022 15:54:52 +0300
Subject: net/mlx5e: Don't match double-vlan packets if cvlan is not set
Patch-mainline: v5.18-rc6
Git-commit: ada09af92e621ab500dd80a16d1d0299a18a1180
References: jsc#PED-1549

Currently, match VLAN rule also matches packets that have multiple VLAN
headers. This behavior is similar to buggy flower classifier behavior that
has recently been fixed. Fix the issue by matching on
outer_second_cvlan_tag with value 0 which will cause the HW to verify the
packet doesn't contain second vlan header.

Fixes: 699e96ddf47f ("net/mlx5e: Support offloading tc double vlan headers match")
Signed-off-by: Vlad Buslov <vladbu@nvidia.com>
Reviewed-by: Maor Dickman <maord@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/net/ethernet/mellanox/mlx5/core/en_tc.c |   11 +++++++++++
 1 file changed, 11 insertions(+)

--- a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
@@ -2459,6 +2459,17 @@ static int __parse_cls_flower(struct mlx
 				 match.key->vlan_priority);
 
 			*match_level = MLX5_MATCH_L2;
+
+			if (!flow_rule_match_key(rule, FLOW_DISSECTOR_KEY_CVLAN) &&
+			    match.mask->vlan_eth_type &&
+			    MLX5_CAP_FLOWTABLE_TYPE(priv->mdev,
+						    ft_field_support.outer_second_vid,
+						    fs_type)) {
+				MLX5_SET(fte_match_set_misc, misc_c,
+					 outer_second_cvlan_tag, 1);
+				spec->match_criteria_enable |=
+					MLX5_MATCH_MISC_PARAMETERS;
+			}
 		}
 	} else if (*match_level != MLX5_MATCH_NONE) {
 		/* cvlan_tag enabled in match criteria and