[ofw] partial review of mlx4 branch

[Hefty, Sean]

> How would a kernel driver establish a trusted communications link with a user-
> space path record service?
> What is the failover position for the case when the user-space PR agent is
> unavailable?
> Would a caching user-space PR agent be accessible from other nodes?

well, opensm is a user space service...

Communication with a service can be done using QP 1, through TCP/IP, or some other means, like named pipes.  We're only limited by what Windows supports in the kernel.  The location of the service doesn't have to be local, as long as the address is known.

This raises an issue with the Windows stack, in that access to QP0/1 are open to any application that wishes to create havoc on the subnet.