Detect of BHyve VM was powered off or rebooted?

[Craig Rodrigues]

Hi,

I posted some rc.d scripts that I am using to boot a BHyve VM
and send the output to a serial console using the /dev/nmdm
driver:

http://lists.freebsd.org/pipermail/freebsd-virtualization/2014-January/002040.html

It works quite well.  There is some things I would like to improve,
and would like some advice on the best way to do it.

(1)  If the VM was destroyed with bhyvectl --destroy --vm ${VM_NAME},
      then I do not want to automatically restart the VM in the script.
      User should manually:  service bhyvevm start

(2)  If the VM was powered down, via shutdown -p, or halt -p,
       then in my script I do not want to restart the VM in the script.
       User should manually:  service bhyvevm start

(3)   If the VM was rebooted via "reboot" or "shutdown -r",
       then I *do* want the script to restart the VM.

I think if I change my start_vm.sh script to do something like:



(
 while [ -e /dev/vmm/${VM} ]; do
    /usr/sbin/bhyve -c 16 -m 8G -A -H -P -g 0 -s 0:0,hostbridge -s 1:0,lpc
-s 2:0,virtio-net,${TAP} -s 3:0,virtio-blk,${IMG} -l com1,${CONS_A} ${VM}"
 done

)  &


then this might cover cases (1) and (3), but what will cover
case (2)?

Thanks for any advice.

--
Craig