[openib-general] Re: [RFC] userspace CM/verbs QP

[Libor Michalek]

On Mon, Mar 07, 2005 at 11:14:07AM -0800, Sean Hefty wrote:
> Roland Dreier wrote:
> >  1. Don't worry about checking.  There's nothing too evil a CM user
> >     can do with a QP beyond getting another QP to connect to it, since
> >     the CM user can't modify a QP unless it legitimately owns it.  And
> >     an evil user can always guess the QPN instead of the QP handle anyway.
> > 
> >  2. Change the CM API so that it just takes the QPN, QP type, SRQ
> >     status and device directly rather than reading it out of the QP.
> >     This lets the userspace CM just get the info from userspace
> >     without needing to look at the QP at all.  Of course it does raise
> >     the issue of how userspace should specify the device.
> > 
> >  3. Merge the userspace CM into userspace verbs support so they use
> >     the same context.  Ugh.
> > 
> > Personally I would lean slightly towards #2, since it feels to me like
> > even the kernel CM API would be cleaner that way.  However I don't
> > have a good answer for how userspace should specify which device to
> > use.
> 
> Which of these options is being used?  It seems like option #2 would 
> work as long as there's a way to locate a device based on a GID.

Sean, I'm not sure there's an easy way to perform a port source GID
to device lookup, did you have something specific in mind for the
lookup? Unless there's an easy way to do this, I was going to go ahead
with #1...

-Libor