net/mlx5e: Properly set steering match levels for offloaded TC decap rules

The match level computed by the driver gets to be wrong for decap
rules with wildcarded inner packet match such as:

tc filter add dev vxlan_sys_4789 protocol all parent ffff: prio 2 flower
       enc_dst_ip 192.168.0.9 enc_key_id 100 enc_dst_port 4789
       action tunnel_key unset
       action mirred egress redirect dev eth1

The FW errs for a missing matching meta-data indicator for the outer
headers (where we do have a match), and a wrong matching meta-data
indicator for the inner headers (where we don't have a match).

Fix that by taking into account the matching on the tunnel info and
relating the match level of the encapsulated packet to the firmware
inner headers indicator in case of decap.

As for vxlan we mandate a match on the tunnel udp dst port, and in general
we practically madndate a match on the source or dest ip for any IP tunnel,
the fix was done in a minimal manner around the tunnel match parsing code.

Fixes: d708f902 ('net/mlx5e: Get the required HW match level while parsing TC flow matches')
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Reported-by: Slava Ovsiienko <viacheslavo@mellanox.com>
Reviewed-by: Jianbo Liu <jianbol@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun.c

@@ -612,16 +612,18 @@ int mlx5e_tc_tun_parse(struct net_device *filter_dev,
 		       struct mlx5_flow_spec *spec,
 		       struct tc_cls_flower_offload *f,
 		       void *headers_c,
-		       void *headers_v)
+		       void *headers_v, u8 *match_level)
 {
 	int tunnel_type;
 	int err = 0;
 
 	tunnel_type = mlx5e_tc_tun_get_type(filter_dev);
 	if (tunnel_type == MLX5E_TC_TUNNEL_TYPE_VXLAN) {
+		*match_level = MLX5_MATCH_L4;
 		err = mlx5e_tc_tun_parse_vxlan(priv, spec, f,
 					       headers_c, headers_v);
 	} else if (tunnel_type == MLX5E_TC_TUNNEL_TYPE_GRETAP) {
+		*match_level = MLX5_MATCH_L3;
 		err = mlx5e_tc_tun_parse_gretap(priv, spec, f,
 						headers_c, headers_v);
 	} else {

drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun.h

@@ -39,6 +39,6 @@ int mlx5e_tc_tun_parse(struct net_device *filter_dev,
 		       struct mlx5_flow_spec *spec,
 		       struct tc_cls_flower_offload *f,
 		       void *headers_c,
-		       void *headers_v);
+		       void *headers_v, u8 *match_level);
 
 #endif //__MLX5_EN_TC_TUNNEL_H__

drivers/net/ethernet/mellanox/mlx5/core/en_tc.c

@@ -1302,7 +1302,7 @@ static void mlx5e_tc_del_flow(struct mlx5e_priv *priv,
 static int parse_tunnel_attr(struct mlx5e_priv *priv,
 			     struct mlx5_flow_spec *spec,
 			     struct tc_cls_flower_offload *f,
-			     struct net_device *filter_dev)
+			     struct net_device *filter_dev, u8 *match_level)
 {
 	struct netlink_ext_ack *extack = f->common.extack;
 	void *headers_c = MLX5_ADDR_OF(fte_match_param, spec->match_criteria,
@@ -1317,7 +1317,7 @@ static int parse_tunnel_attr(struct mlx5e_priv *priv,
 	int err = 0;
 
 	err = mlx5e_tc_tun_parse(filter_dev, priv, spec, f,
-				 headers_c, headers_v);
+				 headers_c, headers_v, match_level);
 	if (err) {
 		NL_SET_ERR_MSG_MOD(extack,
 				   "failed to parse tunnel attributes");
@@ -1426,7 +1426,7 @@ static int __parse_cls_flower(struct mlx5e_priv *priv,
 			      struct mlx5_flow_spec *spec,
 			      struct tc_cls_flower_offload *f,
 			      struct net_device *filter_dev,
-			      u8 *match_level)
+			      u8 *match_level, u8 *tunnel_match_level)
 {
 	struct netlink_ext_ack *extack = f->common.extack;
 	void *headers_c = MLX5_ADDR_OF(fte_match_param, spec->match_criteria,
@@ -1477,7 +1477,7 @@ static int __parse_cls_flower(struct mlx5e_priv *priv,
 		switch (key->addr_type) {
 		case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
 		case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
-			if (parse_tunnel_attr(priv, spec, f, filter_dev))
+			if (parse_tunnel_attr(priv, spec, f, filter_dev, tunnel_match_level))
 				return -EOPNOTSUPP;
 			break;
 		default:
@@ -1826,11 +1826,11 @@ static int parse_cls_flower(struct mlx5e_priv *priv,
 	struct mlx5_core_dev *dev = priv->mdev;
 	struct mlx5_eswitch *esw = dev->priv.eswitch;
 	struct mlx5e_rep_priv *rpriv = priv->ppriv;
+	u8 match_level, tunnel_match_level = MLX5_MATCH_NONE;
 	struct mlx5_eswitch_rep *rep;
-	u8 match_level;
 	int err;
 
-	err = __parse_cls_flower(priv, spec, f, filter_dev, &match_level);
+	err = __parse_cls_flower(priv, spec, f, filter_dev, &match_level, &tunnel_match_level);
 
 	if (!err && (flow->flags & MLX5E_TC_FLOW_ESWITCH)) {
 		rep = rpriv->rep;
@@ -1846,10 +1846,12 @@ static int parse_cls_flower(struct mlx5e_priv *priv,
 		}
 	}
 
-	if (flow->flags & MLX5E_TC_FLOW_ESWITCH)
+	if (flow->flags & MLX5E_TC_FLOW_ESWITCH) {
 		flow->esw_attr->match_level = match_level;
-	else
+		flow->esw_attr->tunnel_match_level = tunnel_match_level;
+	} else {
 		flow->nic_attr->match_level = match_level;
+	}
 
 	return err;
 }

drivers/net/ethernet/mellanox/mlx5/core/eswitch.h

@@ -312,6 +312,7 @@ struct mlx5_esw_flow_attr {
 	} dests[MLX5_MAX_FLOW_FWD_VPORTS];
 	u32	mod_hdr_id;
 	u8	match_level;
+	u8	tunnel_match_level;
 	struct mlx5_fc *counter;
 	u32	chain;
 	u16	prio;

drivers/net/ethernet/mellanox/mlx5/core/eswitch_offloads.c

@@ -160,14 +160,15 @@ mlx5_eswitch_add_offloaded_rule(struct mlx5_eswitch *esw,
 		MLX5_SET_TO_ONES(fte_match_set_misc, misc,
 				 source_eswitch_owner_vhca_id);
 
-	if (attr->match_level == MLX5_MATCH_NONE)
-		spec->match_criteria_enable = MLX5_MATCH_MISC_PARAMETERS;
-	else
-		spec->match_criteria_enable = MLX5_MATCH_OUTER_HEADERS |
-					      MLX5_MATCH_MISC_PARAMETERS;
-
-	if (flow_act.action & MLX5_FLOW_CONTEXT_ACTION_DECAP)
-		spec->match_criteria_enable |= MLX5_MATCH_INNER_HEADERS;
+	spec->match_criteria_enable = MLX5_MATCH_MISC_PARAMETERS;
+	if (flow_act.action & MLX5_FLOW_CONTEXT_ACTION_DECAP) {
+		if (attr->tunnel_match_level != MLX5_MATCH_NONE)
+			spec->match_criteria_enable |= MLX5_MATCH_OUTER_HEADERS;
+		if (attr->match_level != MLX5_MATCH_NONE)
+			spec->match_criteria_enable |= MLX5_MATCH_INNER_HEADERS;
+	} else if (attr->match_level != MLX5_MATCH_NONE) {
+		spec->match_criteria_enable |= MLX5_MATCH_OUTER_HEADERS;
+	}
 
 	if (flow_act.action & MLX5_FLOW_CONTEXT_ACTION_MOD_HDR)
 		flow_act.modify_id = attr->mod_hdr_id;