QubesHVm: restore private.img support
QubesHVm: restore private.img support

marmarek/qubes-core-admin,QubesOS/qubes-core-admin,woju/qubes-core-admin,marmarek/qubes-core-admin,woju/qubes-core-admin,woju/qubes-core-admin,marmarek/qubes-core-admin,woju/qubes-core-admin,QubesOS/qubes-core-admin,QubesOS/qubes-core-admin