virtfs-9p-kmod based on code from Juniper

Build tested on 12.x, 13.x and 14.x. Run tested on 12.x.

Add these flags to bhyve: -s 28,virtio-9p,9p=/some/local/path

In the bhyve VM, load the module and then:

mount -t virtfs -o trans=virtio 9p /some/vm/path

See also:

• 9p review for bhyve
• lib9p
• 9P
• 9P protocol