iavf: add support for offloading tc U32 cls filters

iavf: add support for offloading tc U32 cls filters

Add support for offloading cls U32 filters. Only "skbedit queue_mapping"
and "drop" actions are supported. Also, only "ip" and "802_3" tc
protocols are allowed. The PF must advertise the VIRTCHNL_VF_OFFLOAD_TC_U32
capability flag.

Since the filters will be enabled via the FD stage at the PF, a new type
of FDIR filters is added and the existing list and state machine are used.

The new filters can be used to configure flow directors based on raw
(binary) pattern in the rx packet.

Examples:

0. # tc qdisc add dev enp175s0v0  ingress

1. Redirect UDP from src IP 192.168.2.1 to queue 12:

    # tc filter add dev <dev> protocol ip ingress u32 \
	match u32 0x45000000 0xff000000 at 0  \
	match u32 0x00110000 0x00ff0000 at 8  \
	match u32 0xC0A80201 0xffffffff at 12 \
	match u32 0x00000000 0x00000000 at 24 \
	action skbedit queue_mapping 12 skip_sw

2. Drop all ICMP:

    # tc filter add dev <dev> protocol ip ingress u32 \
	match u32 0x45000000 0xff000000 at 0  \
	match u32 0x00010000 0x00ff0000 at 8  \
	match u32 0x00000000 0x00000000 at 24 \
	action drop skip_sw

3. Redirect ICMP traffic from MAC 3c:fd:fe:a5:47:e0 to queue 7
   (note proto: 802_3):

   # tc filter add dev <dev> protocol 802_3 ingress u32 \
	match u32 0x00003CFD 0x0000ffff at 4   \
	match u32 0xFEA547E0 0xffffffff at 8   \
	match u32 0x08004500 0xffffff00 at 12  \
	match u32 0x00000001 0x000000ff at 20  \
	match u32 0x0000 0x0000 at 40          \
	action skbedit queue_mapping 7 skip_sw

Notes on matches:
1 - All intermediate fields that are needed to parse the correct PTYPE
    must be provided (in e.g. 3: Ethernet Type 0x0800 in MAC, IP version
    and IP length: 0x45 and protocol: 0x01 (ICMP)).
2 - The last match must provide an offset that guarantees all required
    headers are accounted for, even if the last header is not matched.
    For example, in #2, the last match is 4 bytes at offset 24 starting
    from IP header, so the total is 14 (MAC) + 24 + 4 = 42, which is the
    sum of MAC+IP+ICMP headers.

Reviewed-by: Sridhar Samudrala <sridhar.samudrala@intel.com>
Reviewed-by: Marcin Szycik <marcin.szycik@linux.intel.com>
Signed-off-by: Ahmed Zaki <ahmed.zaki@intel.com>
Tested-by: Rafal Romanowski <rafal.romanowski@intel.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>