[openib-general] [RFC] userspace IB SA support

[Sean Hefty]

Sean Hefty wrote:
> Adding this functionality to the existing ib_umad module would add an extra
> dependency of ib_umad on the ib_sa module.  Multicast join / leave operations
> could be done by adding additional IOCTLs, by embedding the request as a
> send_mad call, or by modifying the ib_umad send interface.

Given that the ibibumad interface is intended to send and receive MADs, I would 
rather not abuse the interface by changing the behavior of umad_send/umad_recv. 
  These calls map directly to ib_umad write and read.

Would we be okay with extending the IOCTL interface to allow multicast joins, 
notice registration, and event reporting?  Or would it be acceptable to change 
the ib_umad read/write interface to add a command?

> As an alternative, a new kernel userspace SA module could be created to
> explicitly interface with the kernel ib_sa.

Or do people preferred this approach over changing the ib_umad interface?

I'm looking for something that will be acceptable to merge upstream.

- Sean