A kernel level message passing service

[Bryce Bockman]

I have recently become aware of work being done to incorporate certain
types of services (ex: web servers) into the kernel of unix systems, so
as to take away a level of abstraction, and eliminate the overhead in
performing system calls from user space, thus creating a more efficient
server.

My question is this:

Does is make sense that this sort of thing could be applied to a message
passing interfaces for any sizable gain in performance?  If so, is there
any work already being done on this topic?

My initial reaction to the thought is that there would be all kinds of
security issues, but maybe some sort of "safe" API could be developed to
address these issues.

Cheers,
Bryce Bockman