[ofw] ndrping issues

[Fab Tillier]

Hefty, Sean wrote on Tue, 5 Jan 2010 at 12:43:39

>> I'd think I'd like to see GetConnectionData cap the inbound read limit
>> to what the HCA can support, and CreateEndpoint check that the provided
>> OutboundReadLimit doesn't exceed what was offered.  I'll fix the test
>> to not be busted, though.
> 
> GetConnectionData() is only for the active side.  I don't see a way for
> the server side to see what value was offered in the REQ.  So,
> someplace in the code needs to cap the limits.

No, it's for both active and passive.  The passive side calls it after GetConnectionRequest completes, but before calling CreateEndpoint and Accept.

> Winverbs pushed the checks to the user and expected the HCA driver to
> enforce the values in the kernel.

Having the HCA driver enforce the values should happen regardless.

The CM will cap the responder resources given in the REP to the limit of the HCA already (see __save_user_rep.)  So if GetConnectionData doesn't cap the values, the code *could* allow a larger value to be specified and silently cap it by using the value the CM stores in the REP.  A bit kludge, though.

Pushing the check on the client is fine, though - MSMPI does the checks currently.

-Fab