On Mon, Jul 16, 2018 at 11:03:53PM +0300, Yuval Shaia wrote: > 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: > ---------------- > 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. Eh? The entire reason the kernel forbis multiple registrations is because it has no way to de-multiplex them.. If you want to de-multiplex based on GRH.GID, or DMAC, we could probably arrange for the kernel to support that kind of model.. Maybe it is even already done via the steering APIs? Jason -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
