Documentation/infiniband/opa_vnic.rst

2 Intel Omni-Path (OPA) Virtual Network Interface Controller (VNIC)
5 Intel Omni-Path (OPA) Virtual Network Interface Controller (VNIC) feature
6 supports Ethernet functionality over Omni-Path fabric by encapsulating
7 the Ethernet packets between HFI nodes.
11 The patterns of exchanges of Omni-Path encapsulated Ethernet packets
12 involves one or more virtual Ethernet switches overlaid on the Omni-Path
13 fabric topology. A subset of HFI nodes on the Omni-Path fabric are
14 permitted to exchange encapsulated Ethernet packets across a particular
15 virtual Ethernet switch. The virtual Ethernet switches are logical
18 nodes across the fabric exchange encapsulated Ethernet packets over a
19 single virtual Ethernet switch. A virtual Ethernet switch, is effectively
20 an independent Ethernet network. The configuration is performed by an
21 Ethernet Manager (EM) which is part of the trusted Fabric Manager (FM)
23 different virtual Ethernet switch. The below diagram presents a case
24 of two virtual Ethernet switches with two HFI nodes::
26                                +-------------------+
28                                |     Ethernet      |
30                                +-------------------+
35   +-----------------------------+  +------------------------------+
36   |  Virtual Ethernet Switch    |  |  Virtual Ethernet Switch     |
37   |  +---------+    +---------+ |  | +---------+    +---------+   |
39   +--+---------+----+---------+-+  +-+---------+----+---------+---+
45        +-----------+------------+  +-----------+------------+
47        +-----------+------------+  +-----------+------------+
49        +------------------------+  +------------------------+
52 The Omni-Path encapsulated Ethernet packet format is as described below.
58 0-19                 SLID (lower 20 bits)
59 20-30                Length (in Quad Words)
61 32-51                DLID (lower 20 bits)
62 52-56                SC (Service Class)
63 57-59                RC (Routing Control)
65 61-62                L2 (=10, 16B format)
69 0-7                  L4 type (=0x78 ETHERNET)
70 8-11                 SLID[23:20]
71 12-15                DLID[23:20]
72 16-31                PKEY
73 32-47                Entropy
74 48-63                Reserved
77 0-15                 Reserved
78 16-31                L4 header
79 32-63                Ethernet Packet
81 Quad Words 3 to N-1:
82 0-63                 Ethernet packet (pad extended)
85 0-23                 Ethernet packet (pad extended)
86 24-55                ICRC
87 56-61                Tail
88 62-63                LT (=01, Link Transfer Tail Flit)
91 Ethernet packet is padded on the transmit side to ensure that the VNIC OPA
97 The L4 header field contains the virtual Ethernet switch id the VNIC port
98 belongs to. On the receive side, this field is used to de-multiplex the
116 net_device_ops functions. It expects Omni-Path encapsulated Ethernet
118 the Omni-Path header from the received packets before passing them up
122 It consists of two parts. The VNIC Ethernet Management Agent (VEMA)
124 IB MAD stack. It exchanges the management information with the Ethernet
128 operation. It also handles the encapsulation of Ethernet packets with an
129 Omni-Path header in the transmit path. For each VNIC interface, the
134         +-------------------+ +----------------------+
138         +-------------------+ +----------------------+
141         +----------------------------+      |
147         +----------------------------+      |
150            +------------------+             |
152            +------------------+             |
155         +--------------------------------------------+
159         +--------------------------------------------+