[ofw] typical values for ci_umv_buf_t

[Sean Hefty]

>IBAL calls uvp:post() in query_av verb even when the uvp:pre() returns
>IB_VERBS_PROCESSING_DONE
>in order to return pd (which absent in the pre() prototype)
>I think there is no need for that in create_av verb.

What about the following idea?

Add new AV calls to the uvp3_interface_t structure that I mentioned in my other
email to create/destroy address vectors.  Internally to the existing uvp, these
would just call the current pre/post routines.

A new uvp that wanted to implement these calls would simply either have to do
everything in userspace, or perform their own IOCTLs to the kernel WV driver.
(The IOCTLs would be defined, but missing the kernel implementation until it's
actually needed by someone.)

I think this would be cleaner than trying to handle IB_VERBS_PROCESSING_DONE.

- Sean