Andrew> What is a userspace protection domain? A protection domain is an abstraction enforced by IB hardware -- loosely put, every resource (work queue, memory region, etc) in put in a PD when it is created, and different resources can only see each other if they belong to the same PD.
As an example, PDs are needed because IB allows unprivileged processes to directly post requests to work queues. Work requests refer to memory regions by memory keys (32 bit cookies). Without PDs, a process could get access to another process's memory region if it could guess the 32-bit key -- with PDs, it can't because the other process's memory region will be in a different PD from its work queue. - R. _______________________________________________ openib-general mailing list openib-general@openib.org http://openib.org/mailman/listinfo/openib-general To unsubscribe, please visit http://openib.org/mailman/listinfo/openib-general
