What were you trying to do that didn't work?

Attaching device with unsupported target ccw addr gets unclear error message. In code, it mainly uses info->alias to check, others are 'null'. But sometimes we may not necessarily use alias.

Please provide the package NVR for which bug is seen:

libvirt-9.5.0-7.el9_3.x86_64
qemu-kvm-8.1.0-4.el9.x86_64

How reproducible:

100%

Steps to reproduce

For disk device:

# virsh attach-disk rhel /var/lib/libvirt/images/test.img vdb --targetbus virtio --address ccw:00.0.0000
error: Failed to attach disk
error: unsupported configuration: cannot use CCW address type for device '<null>' using machine type 'pc-q35-rhel9.2.0' 

For scsi controller:

# cat controller.xml 
<controller type='scsi' index='10'>
   <address type='ccw' cssid='0x0' ssid='0x0' devno='0x0000'/>
</controller> 
# virsh attach-device rhel controller.xml 
error: Failed to attach device from controller.xml
error: unsupported configuration: cannot use CCW address type for device '<null>' using machine type 'pc-q35-rhel9.2.0'

Same with other devices.

Expected results

Use device name to check, for example:

cannot use CCW address type for device 'vdb' using machine type 'pc-q35-rhel9.2.0'

or

cannot use CCW address type for device 'controller' using machine type 'pc-q35-rhel9.2.0'

Actual results

If we don't use alias, the error will use '<null>' which is not clear.