[ofa-general] Re: [PATCH] core/cm: improverequestmessage interpretation of subnet local fields

[Jason Gunthorpe]

On Mon, Sep 17, 2007 at 02:29:15PM -0500, Jim Hall wrote:
> Is it valid to have a CM request message with subnet local = 1 and hop 
> limit > 1?

Oop, I hadn't considered the subnet local field. That should probably
unconditionally control the GRH, like your patch.

Hmm, you know, there is compliance statement C9-43.1.2 that is not
reflected in the flow diagram of Figure 81, so the GRH
presence/absence is explicitly matched. My bad.

> C9-43.1.2: For RC, RD and UC services, if a received packet is
> consistent with the configuration of the QP (or EEC) with respect to
> the presence or absence of a GRH, then the packet shall be
> considered to have passed the GRH check, subject to the remaining
> GRH checks described in the rest of Section 9.6.1.2 GRH Checks on
> page 274.

One thing though, if the subnet local = 0 and the incoming hop limit
<= 1 a GRH will still not be used. Your patch should probably also
force the hop limit to 2 in this case and include a note for later
fixup..

Jason