qemu-e2k/contrib/rdmacm-mux/rdmacm-mux.h
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

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1.4 KiB
C

/*
* QEMU paravirtual RDMA - rdmacm-mux declarations
*
* Copyright (C) 2018 Oracle
* Copyright (C) 2018 Red Hat Inc
*
* Authors:
* Yuval Shaia <yuval.shaia@oracle.com>
* Marcel Apfelbaum <marcel@redhat.com>
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*
*/
#ifndef RDMACM_MUX_H
#define RDMACM_MUX_H
#include "linux/if.h"
#include "infiniband/verbs.h"
#include "infiniband/umad.h"
#include "rdma/rdma_user_cm.h"
typedef enum RdmaCmMuxMsgType {
RDMACM_MUX_MSG_TYPE_REQ = 0,
RDMACM_MUX_MSG_TYPE_RESP = 1,
} RdmaCmMuxMsgType;
typedef enum RdmaCmMuxOpCode {
RDMACM_MUX_OP_CODE_REG = 0,
RDMACM_MUX_OP_CODE_UNREG = 1,
RDMACM_MUX_OP_CODE_MAD = 2,
} RdmaCmMuxOpCode;
typedef enum RdmaCmMuxErrCode {
RDMACM_MUX_ERR_CODE_OK = 0,
RDMACM_MUX_ERR_CODE_EINVAL = 1,
RDMACM_MUX_ERR_CODE_EEXIST = 2,
RDMACM_MUX_ERR_CODE_EACCES = 3,
RDMACM_MUX_ERR_CODE_ENOTFOUND = 4,
} RdmaCmMuxErrCode;
typedef struct RdmaCmMuxHdr {
RdmaCmMuxMsgType msg_type;
RdmaCmMuxOpCode op_code;
union ibv_gid sgid;
RdmaCmMuxErrCode err_code;
} RdmaCmUHdr;
typedef struct RdmaCmUMad {
struct ib_user_mad hdr;
char mad[RDMA_MAX_PRIVATE_DATA];
} RdmaCmUMad;
typedef struct RdmaCmMuxMsg {
RdmaCmUHdr hdr;
int umad_len;
RdmaCmUMad umad;
} RdmaCmMuxMsg;
#endif