Interface for communicating from kernel to user mode

[Peter Skvarka <ps%softinengines.com@localhost>]

Hello,
what is suitable interface or mechanism on NetBSD to send message with 
some data from kernel-mode code to user-mode process ?
For example in the past on Linux I used on call nlmsg_unicast(socket, 
buffer, pid) to send data to some user-mode process.