net/mlx5e: VF tunnel RX traffic offloading

net/mlx5e: VF tunnel RX traffic offloading

When tunnel endpoint is on VF the encapsulated RX traffic is exposed on the
representor of the VF without any further processing of rules installed on
the VF. Detect such case by checking if the device returned by route lookup
in decap rule handling code is a mlx5 VF and handle it with new redirection
tables API.

Example TC rules for VF tunnel traffic:

1. Rule that encapsulates the tunneled flow and redirects packets from
source VF rep to tunnel device:

$ tc -s filter show dev enp8s0f0_1 ingress
filter protocol ip pref 4 flower chain 0
filter protocol ip pref 4 flower chain 0 handle 0x1
  dst_mac 0a:40:bd:30:89:99
  src_mac ca:2e:a7:3f:f5:0f
  eth_type ipv4
  ip_tos 0/0x3
  ip_flags nofrag
  in_hw in_hw_count 1
        action order 1: tunnel_key  set
        src_ip 7.7.7.5
        dst_ip 7.7.7.1
        key_id 98
        dst_port 4789
        nocsum
        ttl 64 pipe
         index 1 ref 1 bind 1 installed 411 sec used 411 sec
        Action statistics:
        Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0)
        backlog 0b 0p requeues 0
        no_percpu
        used_hw_stats delayed

        action order 2: mirred (Egress Redirect to device vxlan_sys_4789) stolen
        index 1 ref 1 bind 1 installed 411 sec used 0 sec
        Action statistics:
        Sent 5615833 bytes 4028 pkt (dropped 0, overlimits 0 requeues 0)
        Sent software 0 bytes 0 pkt
        Sent hardware 5615833 bytes 4028 pkt
        backlog 0b 0p requeues 0
        cookie bb406d45d343bf7ade9690ae80c7cba4
        no_percpu
        used_hw_stats delayed

2. Rule that redirects from tunnel device to UL rep:

$ tc -s filter show dev vxlan_sys_4789 ingress
filter protocol ip pref 4 flower chain 0
filter protocol ip pref 4 flower chain 0 handle 0x1
  dst_mac ca:2e:a7:3f:f5:0f
  src_mac 0a:40:bd:30:89:99
  eth_type ipv4
  enc_dst_ip 7.7.7.5
  enc_src_ip 7.7.7.1
  enc_key_id 98
  enc_dst_port 4789
  enc_tos 0
  ip_flags nofrag
  in_hw in_hw_count 1
        action order 1: tunnel_key  unset pipe
         index 2 ref 1 bind 1 installed 434 sec used 434 sec
        Action statistics:
        Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0)
        backlog 0b 0p requeues 0
        used_hw_stats delayed

        action order 2: mirred (Egress Redirect to device enp8s0f0_1) stolen
        index 4 ref 1 bind 1 installed 434 sec used 0 sec
        Action statistics:
        Sent 129936 bytes 1082 pkt (dropped 0, overlimits 0 requeues 0)
        Sent software 0 bytes 0 pkt
        Sent hardware 129936 bytes 1082 pkt
        backlog 0b 0p requeues 0
        cookie ac17cf398c4c69e4a5b2f7aabd1b88ff
        no_percpu
        used_hw_stats delayed

Co-developed-by: Dmytro Linkin <dlinkin@nvidia.com>
Signed-off-by: Dmytro Linkin <dlinkin@nvidia.com>
Signed-off-by: Vlad Buslov <vladbu@nvidia.com>
Reviewed-by: Roi Dayan <roid@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>