docs/designs/multihost-ipmi-design.md

1 # Multi-host IPMI design
12 The current version of OpenBMC does not support multi-host implementation in
13 IPMI commands handling. We have a multi-host system and proposing the design to
14 support multi-host.
20 Issue 1: ipmbridged does not send the channel number (ie HostId) Issue 2: ipmid
21 does not have the information on which IPMB channel the request has come from.
30  +------------------------------------+
32  | +-----------+       +------------+ |      +--------+
34  | |           |       |            |-|------| Host-1 |
36  | |           |       |            | |      +--------+
39  | |           | D-Bus |            | |      +--------+
40  | | ipmid     |-------| ipmbbridged| | IPMB2|        |
41  | |           |       |            |-|------| Host-2 |
43  | |           |       |            | |      +--------+
46  | |           |       |            | |      +--------+
48  | |           |       |            |-|------| Host-N |
50  | +-----------+       +------------+ |      +--------+
51  +------------------------------------+
56 requests are routed from ipmid or any service by D-Bus interface and The
61 The current version of OpenBMC does not support multi-host implementation in
62 IPMI commands handling. We have a multi-host system and proposing the design to
63 support multi-host.
68 ipmbbridged and ipmid. To address out-of-band IPMI command from the network,the
73 ipmbbridged to send the channel details from where the request is received.
77 While routing the IPMB requests coming from the host channel, We will be adding
79 will send '"devIndex": 0' as optional parameter(options) in D-Bus interface to
84 channel.To ensure existing platforms does not get affected, if the "devIndex"
87 { "type": "me", "slave-path": "/dev/ipmb-1", "bmc-addr": 32, "remote-addr": 64,
88 "devIndex": 0 }, { "type": "ipmb", "slave-path": "/dev/ipmb-2", "bmc-addr": 32,
89 "remote-addr": 64, "devIndex": 0 }, { "type": "me", "slave-path": "/dev/ipmb-3",
90 "bmc-addr": 32, "remote-addr": 64, "devIndex": 1 }, { "type": "ipmb",
91 "slave-path": "/dev/ipmb-4", "bmc-addr": 32, "remote-addr": 64, "devIndex": 1 },
110 The netipmid sends the "devIndex" on which channel the request comes from. There
112 multiple approaches to handle multi-host.Some of the approaches are listed down
115 1. Virtual Ethernet interfaces - One virtual interface per host.
116 2. Different port numbers - Can have different port numbers for each host.
117 3. VLAN Ids- VLAN IDs can be used to support multi host. The netipmid shall have
122 {"Host":1, "Interface-1":"eth0", "Interface-2":"eth1", "Interface-3":"veth4",
123 "Interface-4":"veth5" }, {"Host":2, "Interface-1":"eth2", "Interface-2":"eth3",
124 "Interface-3":"veth1", "Interface-4":"veth2" },
129 +--------------------------------------------+
131 | +--------+       +-----------+   +------+  |      +--------+
132 | |        | D-Bus |           |   |      |  |      |        |
133 | |        |-------| netipmid1 |---|veth1 |---------| Host-1 |
135 | |        |       +-----------+   +------+  |      +--------+
137 | |        |       +-----------+   +------+  |      +--------+
138 | | ipmid  | D-Bus |           |   |      |  |      |        |
139 | |        |-------| netipmid2 |---|veth2 |---------| Host-2 |
141 | |        |       +-----------+   +------+  |      +--------+
143 | |        |       +-----------+   +------+  |      +--------+
144 | |        | D-Bus |           |   |      |  |      |        |
145 | |        |-------| netipmidN |---|vethN |---------| Host-N |
147 | +--------+       +-----------+   +------+  |      +--------+
148 +--------------------------------------------+
157 ## Approach1:ipmbbridged to send host-id in the payload
165 This is a multi service appoach,one instance of ipmid service shall be spawned
170 ## Approach3:Using a different IPMI channel for handling multiple host.
172 Using a different IPMI channel for handling multiple hosts, in the ipmbbridged
173 the channel id can be used to identify host. In this approach we will be having
175 a channel number.Maximum channel numbers are limited to 8 as per the