xemu/contrib
Yuval Shaia a5d2f6f877 contrib/rdmacm-mux: Add implementation of RDMA User MAD multiplexer
RDMA MAD kernel module (ibcm) disallow more than one MAD-agent for a
given MAD class.
This does not go hand-by-hand with qemu pvrdma device's requirements
where each VM is MAD agent.
Fix it by adding implementation of RDMA MAD multiplexer service which on
one hand register as a sole MAD agent with the kernel module and on the
other hand gives service to more than one VM.

Design Overview:
Reviewed-by: Shamir Rabinovitch <shamir.rabinovitch@oracle.com>
----------------
A server process is registered to UMAD framework (for this to work the
rdma_cm kernel module needs to be unloaded) and creates a unix socket to
listen to incoming request from clients.
A client process (such as QEMU) connects to this unix socket and
registers with its own GID.

TX:
----
When client needs to send rdma_cm MAD message it construct it the same
way as without this multiplexer, i.e. creates a umad packet but this
time it writes its content to the socket instead of calling umad_send().
The server, upon receiving such a message fetch local_comm_id from it so
a context for this session can be maintain and relay the message to UMAD
layer by calling umad_send().

RX:
----
The server creates a worker thread to process incoming rdma_cm MAD
messages. When an incoming message arrived (umad_recv()) the server,
depending on the message type (attr_id) looks for target client by
either searching in gid->fd table or in local_comm_id->fd table. With
the extracted fd the server relays to incoming message to the client.

Signed-off-by: Yuval Shaia <yuval.shaia@oracle.com>
Reviewed-by: Shamir Rabinovitch <shamir.rabinovitch@oracle.com>
Signed-off-by: Marcel Apfelbaum <marcel.apfelbaum@gmail.com>
2018-12-22 11:09:56 +02:00
..
elf2dmp Clean up includes 2018-12-20 10:29:08 +01:00
gitdm contrib: add a basic gitdm config 2018-12-17 08:25:10 +00:00
ivshmem-client Clean up ill-advised or unusual header guards 2016-07-12 16:20:46 +02:00
ivshmem-server Move include qemu/option.h from qemu-common.h to actual users 2018-02-09 13:52:16 +01:00
libvhost-user libvhost-user: support host notifier 2018-05-24 21:14:11 +03:00
rdmacm-mux contrib/rdmacm-mux: Add implementation of RDMA User MAD multiplexer 2018-12-22 11:09:56 +02:00
systemd contrib: add systemd unit files 2017-12-20 22:29:26 +01:00
vhost-user-blk Clean up includes 2018-12-20 10:29:08 +01:00
vhost-user-scsi Clean up includes 2018-12-20 10:29:08 +01:00