Dear Maintainer,

when trying to add a USB CDROM drive which is empty, the VM doesn't start anymore.
Error starting domain: internal error: qemu unexpectedly closed the monitor: 2021-07-27T16:55:41.147567Z qemu-system-aarch64: -device usb-storage,bus=usb.0,port=1,id=usb-disk1,removable=on: drive property not set

	Traceback (most recent call last):
	  File "/usr/share/virt-manager/virtManager/asyncjob.py", line 65, in cb_wrapper
	    callback(asyncjob, *args, **kwargs)
	  File "/usr/share/virt-manager/virtManager/asyncjob.py", line 101, in tmpcb
	    callback(*args, **kwargs)
	  File "/usr/share/virt-manager/virtManager/object/libvirtobject.py", line 57, in newfn
	    ret = fn(self, *args, **kwargs)
	  File "/usr/share/virt-manager/virtManager/object/domain.py", line 1329, in startup
	    self._backend.create()
	  File "/usr/lib/python3/dist-packages/libvirt.py", line 1353, in create
	    raise libvirtError('virDomainCreate() failed')
	libvirt.libvirtError: internal error: qemu unexpectedly closed the monitor: 2021-07-27T16:55:41.147567Z qemu-system-aarch64: -device usb-storage,bus=usb.0,port=1,id=usb-disk1,removable=on: drive property not set

When adding an iso to the drive, the VM can normally be started.


I get this error from virt-manager, but when opening the configuration with virsh, I can see the flag is properly added to the config:
	<disk type='file' device='cdrom'>
		<driver name='qemu' type='raw'/>
		<target dev='sdb' bus='usb' removable='on'/>
		<readonly/>
		<address type='usb' bus='0' port='1'/>
	</disk>


I can't tell, when the bug appeared, because I have not been using a USB cdrom so far.