[dpdk-dev] [PATCH] net/mlx5: set VLAN tag matcher bit properly

[Dekel Peled]

Currently MLX5 PMD can't match on untagged packets specifically.
Tagged traffic still hits the flows intended for untagged packets.
If the flow has ETH, it will catch all matching packets, tagged
and untagged.
The solution is to use cvlan_tag bit.
If mask=1 and value=0 it matches on untagged traffic.
If mask=1 and value=1 it matches on tagged traffic.
This is the kernel implementation.

This patch updated MLX5 PMD to set cvlan_tag mask and value according
to flow rule contents.

Signed-off-by: Dekel Peled <dek...@mellanox.com>
---
 drivers/net/mlx5/mlx5_flow_dv.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/drivers/net/mlx5/mlx5_flow_dv.c b/drivers/net/mlx5/mlx5_flow_dv.c
index 3daabd3..a28af7c 100644
--- a/drivers/net/mlx5/mlx5_flow_dv.c
+++ b/drivers/net/mlx5/mlx5_flow_dv.c
@@ -5214,6 +5214,15 @@ struct field_modify_info modify_tcp[] = {
                 rte_be_to_cpu_16(eth_m->type));
        l24_v = MLX5_ADDR_OF(fte_match_set_lyr_2_4, headers_v, ethertype);
        *(uint16_t *)(l24_v) = eth_m->type & eth_v->type;
+       if (eth_v->type) {
+               /* When ethertype is present set mask for tagged VLAN. */
+               MLX5_SET(fte_match_set_lyr_2_4, headers_m, cvlan_tag, 1);
+               /* Set value for tagged VLAN if ethertype is 802.1Q. */
+               if (eth_v->type == RTE_BE16(RTE_ETHER_TYPE_VLAN) ||
+                   eth_v->type == RTE_BE16(RTE_ETHER_TYPE_QINQ))
+                       MLX5_SET(fte_match_set_lyr_2_4, headers_v, cvlan_tag,
+                                1);
+       }
 }
 
 /**
@@ -5354,6 +5363,7 @@ struct field_modify_info modify_tcp[] = {
                 ipv4_m->hdr.next_proto_id);
        MLX5_SET(fte_match_set_lyr_2_4, headers_v, ip_protocol,
                 ipv4_v->hdr.next_proto_id & ipv4_m->hdr.next_proto_id);
+       MLX5_SET(fte_match_set_lyr_2_4, headers_m, cvlan_tag, 1);
 }
 
 /**
@@ -5458,6 +5468,7 @@ struct field_modify_info modify_tcp[] = {
                 ipv6_m->hdr.proto);
        MLX5_SET(fte_match_set_lyr_2_4, headers_v, ip_protocol,
                 ipv6_v->hdr.proto & ipv6_m->hdr.proto);
+       MLX5_SET(fte_match_set_lyr_2_4, headers_m, cvlan_tag, 1);
 }
 
 /**
-- 
1.8.3.1