[RFC v1 0/3] Unifying fabrics drivers

[Daniel Wagner]

On Tue, Mar 07, 2023 at 11:26:12AM +0200, Sagi Grimberg wrote:
> I think we should make all transports to unify setup/teardown sequences
> (i.e. including pcie and fc). Otherwise we are not gaining much.

Not sure about pcie but I haven't really looked at it. The state machine is
really handling all the fabrics specific queue handling.

Ideally, fc would use the same state machine. Though the current code base is
differs quiet significantly but I can try to convert it too.

> It will help if we make the ops higher level like
> 
> ops.setup_transport(ctrl)
> ops.alloc_admin_queue(ctrl)
> ops.start_admin_queue(ctrl)
> ops.stop_admin_queue(ctrl)
> ops.free_admin_queue(ctrl)
> ops.alloc_io_queues(ctrl)
> ops.start_io_queues(ctrl)
> ops.stop_io_queues(ctrl)
> ops.free_io_queues(ctrl)

This is more ore less what v2 is.

> The init/deinit can be folded to alloc/free I think.

Yes, that would a good thing. In my first attempt I tried to keep things more a
less identically with the existing code, just using the callbacks for the
transport specific bits.

> This is indeed a much larger effort, but I don't know what
> this unification of rdma/tcp buys us really...

My motiviation is that we are keep fixing the same bugs in rdma and tcp
transport since a while. The state machine code is almost identically so why not
trying to reduce the code duplication?

(*) There are a few small things which are not the same.