[ofw] API breakage in trunk

[Sean Hefty]

>I'd like to replace IBAL by WinVerbs, but as far as I remember, it doesn't
>cover all IBAL functionality so far.
>(multicast ?)

It does cover multicast.  WinMad covers MAD layer functionality.  Between the
two, the functionality of the Linux libibverbs, librdmacm, and libibumad APIs
are covered.  IB CM functionality is not, with no current plans to support it.

I'm not suggesting that IBAL be dropped, just the user space work on the
interface cease.

>And what about starting to replace kernel IBAL by WinVerbs ?
>Are there any plans ?

I would like to do this, but do not have the time at this point.  I'm only
discussing the user space APIs with these changes.  For example, if you want to
copy-paste-rename ib_port_attr_t -> ibk_port_attr_t for kernel only clients,
then add these changes, that's fine with me.  The issue is when the changes
affect user space applications.  IMO, even the user to kernel interface changes
are less of a concern.

The guidelines that I use are:

* user space must be backwards compatible
* kernel space can change at will
* user space must support older kernel releases

I do believe that OFED for Windows should adopt these policies.