bhyve in -current 4/14/13 can no longer support FreeBSD stable install

[Peter Grehan]

Hi Alfred,

>> If you do this repeatedly, it may be possible to see some patterns
>> e.g. counters incrementing, %RIP values being the same etc.
>>
> Hmm, I keep seem to be getting this:
> /usr/home/alfred # bhyvectl --get-all --cpu=0 --vm=freebsd-stable
> lowmem 0x0000000000000000/536870912
> highmem 0x0000000100000000/0
> errno = 16
> /usr/home/alfred # bhyvectl --get-all --cpu=1 --vm=freebsd-stable
> lowmem 0x0000000000000000/536870912
> highmem 0x0000000100000000/0
> errno = 16

  Yeh, this is a problem :( Currently, the stats gathering does a 
trylock on the VM to avoid having the VM be perturbed by the bhyvectl 
process. We probably need to put something in there so it can eventually 
get the lock, and hence the stats, when the VM is busy rather than 
forcing the user to retry.

  The work around is to send a SIGSTOP to the bhyve process and then run 
the bhyvectl. A SIGSTART will then set the VM going again.

later,

Peter.