[openib-general] OpenIB and OpenRDMA: Convergence on common RDMAAPIs and ULPs for Linux

[Bob Woodruff]

 Venkat>  I would like to start a discussion around the convergence of RDMA
APIs and ULPs
 Venkat>  between OpenIB and OpenRDMA projects.

There is already a RDMA device independent API being developed for the
kernel
by people on this list. 
It is starting with the kDAPL code base, which was designed to support both
IBA and iWarp devices. People have already started to re-work this code
and API so that meets the Linux coding standards, etc. It is being developed
in an open source way, rather than by some committee. 
I would suggest that it is at this level that iWarp or other RDMA devices
fit into the stack. 
ULPs that want to be able to run on any RDMA device (such as iSer, 
NFS-R) are already coding to this interface.

I am not sure that having one mid-layer is really required, at least
initially.
Once the RNIC people have a mid-layer that interfaces with the RDMA API
(kDAPL 
derivative), we can look at where there might be common code that could be
shared between the InfiniBand mid-layer and the iWarp mid-layer. This would
allow the RNIC vendors to develop code that could use the same ULPs without
slowing down the InfiniBand development.  

Finally, until there is some consensus about allowing TCP offload in Linux, 
I see no need to start to hack up the InfiniBand stack to support iWarp. 

woody