Might be wrong place (i.e. not kern) but not where to file it now that the MS HV drivers/tools are included in the 10.1 base, i.e. ports didn't seem to make sense.
Current on Microsoft HyperV FreeBSD VM is setup in cluster which means every time my system "moves" hosts (blade chassis) I lose my swap drive. Per the the FreeBSD HyperV wiki and Microsoft FBSD BP Guide (https://technet.microsoft.com/en-us/library/dn848317.aspx) this is handled by "Add UUIDs for all devices listed in fstab" yet doesn't seem to work. Output below:
root@prh-i-sec:/home/pthoenen # swapinfo
Device 1K-blocks Used Avail Capacity
root@prh-i-sec:/home/pthoenen # swapon -a
swapon: /dev/gptid/a6822e47-dcc4-11e4-88a9-00155d29501f: No such file or directory
root@prh-i-sec:/home/pthoenen # cat /etc/fstab
# Device Mountpoint FStype Options Dump Pass#
/dev/gptid/a6822e47-dcc4-11e4-88a9-00155d29501f none swap sw 0 0
[..cut the rest such as proc .. the main drives are all via zfs..]
root@prh-i-sec:/home/pthoenen # ls /dev/gpt/
root@prh-i-sec:/home/pthoenen # gpart list | grep -A 11 'da0p2' | grep 'rawuuid\|type\|Name'
2. Name: da0p2
You're fine, "kern" is as close of a place as we have ATM.