[openib-general] [PATCH] add cq error events

[Sean Hefty]

Caitlin Bestler wrote:
> If the semantics were defined such that an overrun meant
> that an event had been lost, but that the CQ was still
> intact, then the user can definitely adjust and continue.

My understanding is that a CQ overrun error is fatal.  No additional entries may 
be added to that CQ.  All QPs associated with the CQ will generate an error the 
next time that they try to access it.  And outstanding completions on the CQ may 
not be retrievable.  See IB spec 11.6.3.2, C11-38.

C11-37 and C11-38 talk about generating a CQ Error on non-overrun errors and 
overrun errors.  So I'm not sure if its a requirement for hardware to 
distinguish between the cause of the error.

- Sean