FreeBSD based VM's work fine here

FreeBSD odyssey 11.0-CURRENT FreeBSD 11.0-CURRENT #83 r275732: Fri Dec 12 16:48:37 EST 2014     root@odyssey:/usr/obj/home/db/svn/system/head/sys/GENERIC  amd64

https://www.freebsd.org/doc/handbook/virtualization-host-bhyve.html

# more device.map
(hd0) /bhyve/linux.img
(cd0) /bhyve/ubuntu-13.10-server-amd64.iso

# grub-bhyve -m device.map -r cd0 -M 1024M linuxguest


# bhyve -AI -H -P -s 0:0,hostbridge -s 1:0,lpc -s 2:0,virtio-net,tap1 -s 3:0,virtio-blk,./linux.img -s 4:0,ahci-cd,./ubuntu-13.10-server-amd64.iso -l com1,stdio -c 4 -m 1024M linuxguest
Assertion failed: (error == 0), function fbsdrun_addcpu, file /home/db/svn/system/head/usr.sbin/bhyve/bhyverun.c, line 266.
                                           zsh: abort (core dumped)  bhyve -AI -H -P -s 0:0,hostbridge -s 1:0,lpc -s 2:0,virtio-net,tap1 -s  -s  -
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