Add support for multiple TX and RX queue pairs. The default number of queues
is set to 4, but can be easily changed from the sysctl node hw.xn.num_queues.
Also heavily refactor netfront driver: break out a bunch of helper
functions and different structures. Use threads to handle TX and RX.
Remove some dead code and fix quite a few bugs as I go along.
Submitted by: Wei Liu <wei.liu2@citrix.com>
Reviewed by: royger
Sponsored by: Citrix Systems R&D
Relnotes: Yes
Differential Revision: https://reviews.freebsd.org/D4193
cbb7a2ba43