Booting Linux (eg Fedora) guest VBox on /dev/mapper/vg0-fc17-root:

I already have the following logical volumes:

• host:/dev/mapper/vg0-fc17-boot (guestOS:/dev/hdb) formatted as ext4 (no partition table)

• host:/dev/mapper/vg0-fc17-root (guestOS:/dev/hdc) formatted as ext4 (no partition table)

Do I have to create the following grub partition to boot a guest VM under VirtualBox?

• eg host:/dev/mapper/vg-fc17-mbr (guestOS:/dev/hda) with a partition table and install grub MBR here?

Or is there a better way? (Maybe grub on vg0-fc17-boot?)