bhyve + VALE recipe

requires FreeBSD kernel with 
https://github.com/freebsd/freebsd/commit/cac3f209134f9f95a431a8480d1275c640d86d7d#diff-f4318c2cf4a50c29e6990f3e8a8a5286
https://github.com/freebsd/freebsd/commit/7ab2b8809cd93e9b6da4f2284f4a5851deeff012#diff-f4318c2cf4a50c29e6990f3e8a8a5286

or pfense 2.3 snapshot from 8 Jan 2016 or later

1. Launch the first vm with a NIC configured as a vale port:

$ bhyve -A -H -P \
        -s 0:0,hostbridge \
        -s 1:0,lpc \
        -s 2,virtio-blk,./disk-vm1 \
        -s 3:0,virtio-net,vale0:vm1 \
        -l com1,stdio \
        -m 1G -c 2 vm1

2. Launch the second vm with a NIC configured as a vale port:

$ bhyve -A -H -P \
        -s 0:0,hostbridge \
        -s 1:0,lpc \
        -s 2,virtio-blk,./disk-vm2 \
        -s 3:0,virtio-net,vale0:vm2 \
        -l com1,stdio \
        -m 1G -c 2 vm2

Both vale0:vm1 and vale0:vm2 are now ports on vale0 vswitch.

3. Setup the network in each vm:

$ ifconfig vtnet0 192.168.1.1 up     # in 1st vm
$ ifconfig vtnet0 192.168.1.2 up     # in 2nd vm

4. Ping test

# ping -c 5 192.168.1.1              # in  2nd vm
PING 192.168.1.1 (192.168.1.1): 56 data bytes
64 bytes from 192.168.1.1: icmp_seq=0 ttl=64 time=0.513 ms
64 bytes from 192.168.1.1: icmp_seq=1 ttl=64 time=0.356 ms
64 bytes from 192.168.1.1: icmp_seq=2 ttl=64 time=0.523 ms
64 bytes from 192.168.1.1: icmp_seq=3 ttl=64 time=0.362 ms
64 bytes from 192.168.1.1: icmp_seq=4 ttl=64 time=0.532 ms

--- 192.168.1.1 ping statistics ---
5 packets transmitted, 5 packets received, 0.0% packet loss
round-trip min/avg/max/stddev = 0.356/0.457/0.532/0.080 ms