[libvirt] Qemu: create empty cdrom

Hello. Qemu is latest from master branch. Tryingto start a domain, which is connected toa blankcdrom: <disk type='file' device='cdrom'> <driver name='qemu' type='raw'/> <target dev='sdb' bus='scsi'/> <readonly/> <address type='drive' controller='0' target='1' bus='0' unit='0'/> </disk> But I get an error: qemu-system-x86_64: -drive if=none,id=drive-scsi0-0-1-0,readonly=on,format=raw: Can't use 'raw' as a block driver for the protocol level.