[openib-general] fmr question

[Caitlin Bestler]

Steve Wise wrote:
> Something similar to the mw_bind semantics should work to
> make it more like the iwarp fast-register (i'm not sure about
> IB 1.2).  A function like ib_bind_mw() to post the map WR,
> and then a new completion type to post the results back to the CQ...
> 
> Would we just change ib_map_phys_fmr() to do this or create a
> new API function to preserve backwards compatibility?
> 
> 
The rationale for bind_mw() is that the caller needs to
know what the RKey that will be associated with the window
when the bind completes *before* it reaps the completion.

A special method is not required to achieve this when
the RKey is defined to have an index and key portion,
and the new key value is selected by the consumer.
All that is required is to post the work request.

For FMRs that applies to RDMAC, IB 1.2 and RNIC-PI.
Therefore new work request and work completion structs
are all that are required. There is no need for a bind_fmr()
method, anymore than there is for a post_rdma_write() method.