RE: [PATCH 2/2] rdma/cm: allow user to specify IP to DGID mapping

Sean Hefty
2009-10-20T19:13:03Z

>> rdma_bind_addr fills in the service id according RDMA IP CM service
>> annex.
>
>Hm? If the sockaddr_ib contains the service ID why override it in the
>kernel?
>
>The AF_IB/PS_IB flow in the kernel side must just use straight service
>IDs.

I agree. But we can still support AF_IB/PS_TCP by simply assigning the service
ID correctly. rdma_bind_addr only needs to fill in a service id if one is not
given. This should enable interoperability. I realize that IB doesn't have the
concept of a service ID for the active side of a connection, but the RDMA IP CM
Service header carries the source port. And rdma_bind_addr is called by
rdma_resolve_addr, so it needs to be updated.

Even once PS_IB is added, we need to make sure that it doesn't collide with
PS_TCP at the IB service ID level, or IB will be in the same situation that
iWarp is in with space collisions.

- Sean