[openib-general] RDMA connection and address translation API

[Sean Hefty]

>However, there's another problem with trying to lump address
>translation and connection into a single "connect" call, and this
>problem looks fundamental and fatal to me.  The connect call takes a
>QP pointer, but to create a QP the consumer needs to know which local
>device to use.  However, the consumer doesn't know which device to use
>until the destination address has been resolved to a route, including
>a local interface.

I agree that this is a fairly serious issue with the proposed API.  I guess that
I'd like to clarify what the operation of a connect call would do.  Would it be
responsible for modifying the QP?  If so, could such a call also allocate the
QP?  Note that I'm not advocating either of these, just trying to determine what
the behavior of the API would be.

>        Wait for connection requests and pass events to the consumer's
>        callback.  I'm not sure if/home we want to support binding to
>        a particular IP address.  The current IB CM in Linux doesn't
>        support binding a listen to a single device or port, and even
>        if it did it's not clear how to handle binding to one IP
>        address when a port has more than one IP.

I don't think that it would be overly difficult to bind IB CM listen requests to
a specific port or LID, or based on matching specific private data.

- Sean