[openib-general] userspace CM API for per device handling

[Sean Hefty]

Arlin Davis wrote:
> User events are processed (poll/select) with FD's so can we just use the 
> FD to get events? This would give the user a direct mapping back to the 
> correct device based on the poll or select results.
> 
> Something like...
> 
> 5. ib_cm_get_fd( struct ibv_context *device_context)  and  
> ib_cm_get_event(int fd, **event).

I think that this is a good approach.  It avoids searching lists when calling 
ib_cm_get_event(), but still gives the flexibility of per device event handling. 
  Plus users don't have to track CM devices separately from verb devices.

> ibv_get_async_event(int fd, struct ibv_async_event *event);
> ibv_get_cq_event(int fd, struct ibv_cq **cq, void **cq_context);

This makes sense and avoids users from having to map from an fd back to a verbs 
defined data structure, that is used to reference the fd.  Roland, what do you 
think?

- Sean