common/iavf: add virtual channel protocol header

common/iavf: add virtual channel protocol header

To support advanced AVF's FDIR and RSS feature, we need to figure out
what kind of data structure should be passed from VF to PF to describe
an FDIR rule or RSS config rule. The common part of the requirement is
we need a data structure to represent the input set selection of a rule's
hash key.

An input set selection is a group of fields be selected from one or more
network protocol layers that could be identified as a specific flow.
For example, select dst IP address from an IPv4 header combined with
dst port from the TCP header as the input set for an IPv4/TCP flow.

The patch adds a new data structure virtchnl_proto_hdrs to abstract
a network protocol headers group which is composed of layers of network
protocol header(virtchnl_proto_hdr).

A protocol header contains a 32 bits mask (field_selector) to describe
which fields are selected as input sets, as well as a header type
(enum virtchnl_proto_hdr_type). Each bit is mapped to a field in
enum virtchnl_proto_hdr_field guided by its header type.

+------------+-----------+------------------------------+
|            | Proto Hdr | Header Type A                |
|            |           +------------------------------+
|            |           | BIT 31 | ... | BIT 1 | BIT 0 |
|            |-----------+------------------------------+
|Proto Hdrs  | Proto Hdr | Header Type B                |
|            |           +------------------------------+
|            |           | BIT 31 | ... | BIT 1 | BIT 0 |
|            |-----------+------------------------------+
|            | Proto Hdr | Header Type C                |
|            |           +------------------------------+
|            |           | BIT 31 | ... | BIT 1 | BIT 0 |
|            |-----------+------------------------------+
|            |    ....                                  |
+-------------------------------------------------------+

All fields in enum virtchnl_proto_hdr_fields are grouped with header type
and the value of the first field of a header type is always 32 aligned.

enum proto_hdr_type {
	header_type_A = 0;
	header_type_B = 1;
	....
}

enum proto_hdr_field {
	/* header type A */
	header_A_field_0 = 0,
	header_A_field_1 = 1,
	header_A_field_2 = 2,
	header_A_field_3 = 3,

	/* header type B */
	header_B_field_0 = 32, // = header_type_B << 5
	header_B_field_0 = 33,
	header_B_field_0 = 34
	header_B_field_0 = 35,
	....
};

So we have:
proto_hdr_type = proto_hdr_field / 32
bit offset = proto_hdr_field % 32

To simply the protocol header's operations, couple help macros are added.
For example, to select src IP and dst port as input set for an IPv4/UDP
flow.

we have:
struct virtchnl_proto_hdr hdr[2];

VIRTCHNL_SET_PROTO_HDR_TYPE(&hdr[0], IPV4)
VIRTCHNL_ADD_PROTO_HDR_FIELD(&hdr[0], IPV4, SRC)

VIRTCHNL_SET_PROTO_HDR_TYPE(&hdr[1], UDP)
VIRTCHNL_ADD_PROTO_HDR_FIELD(&hdr[1], UDP, DST)

A protocol header also contains a byte array, this field should only
be used by an FDIR rule and should be ignored by RSS. For an FDIR rule,
the byte array is used to store the protocol header of a training
package. The byte array must be network order.

Signed-off-by: Jeff Guo <jia.guo@intel.com>
Signed-off-by: Paul M Stillwell Jr <paul.m.stillwell.jr@intel.com>
Signed-off-by: Qi Zhang <qi.z.zhang@intel.com>
Acked-by: Beilei Xing <beilei.xing@intel.com>