[openib-general] Re: RFC: ipath ioctls and their replacements

[Bryan O'Sullivan]

On Thu, 2006-01-19 at 13:08 -0800, Sean Hefty wrote:

> I'm struggling to understand what your card does then.  From this, it sounds 
> like a standard network card that just happens to use IB physicals.

It has typical features of a standard network card, while also
supporting direct user access to the hardware.  We eschew the
offload-as-much-as-possible approach that other vendors take.

> Do you just send raw packets?

We certainly can do that.  The hardware doesn't need to do much more, in
fact.

> How is the LRH formatted by your card?  I.e. what's setting 
> up the dlid, slid, vl, etc.?

This is all done in software.  The low-level driver and hardware fill
out enough of the IB UD protocol headers to put packets on the wire that
an IB switch will route.  The higher-level layer is responsible for the
full IB protocol suite and the driver-side interfaces to the various
OpenIB userspace APIs.

>   Can your card interoperate with other IB devices 
> on the network when running in this mode?

Yes.  It can do both the low-level wonkery and regular IB at the same
time.

	<b