[ofw] Use of I/O completion port with Winverbs

[Hefty, Sean]

> Actually, I am in the process of deciding which API to use (although I have
> existing librdma code). NetworkDirect indeed looks promising, but as I
> understand, I need HPC Pack 2012 for that which I cannot install on our cluster
> in the short term.

IMO - your best choice of which API to use on Windows at this point is ND.  That is the sanctioned API by Microsoft, and the only API which HW vendors are required to provide.  Future support for winverbs is basically an effort left up to any HW vendors that wish to carry it forward.

> Is it possible to use IOCPs with winverbs?

Yes - winverbs was written such that ND could easily be written over it.

> Is it possible to use IOCPs with the RDMA library?

It is only possible with winverbs and ND as I remember.