6.6 VMs need 320Mb of ram in bhyve

Hi,

  I just upgraded a couple of VMs to 6.6 (thanks to everyone for
another brilliant release!) that used to manage in 256Mb of RAM. They
crash at the stage the kernel loads with that amount in 6.6, and with
288Mb the kernel loading process hangs. It takes 320Mb for them to boot
without any issues. I don't know what's changed but I thought it'd be
worth reporting. I'm using bhyve on FreeBSD 12.0.

Cheers,

Noth