Version-Release number of selected component (if applicable):
libvirt-9.9.0-1.el9.x86_64

How reproducible:
100%

Steps to Reproduce:
1. Preapre a input device xml without specifying the bus type

# cat tablet.xml 
<input type='tablet' />

2. Attach the input device to guest

# virsh attach-device avocado-vt-vm1 mouse.xml --config 
error: Failed to attach device from mouse.xml
error: unsupported configuration: unknown input bus type 'default'

Actual results:
Can not plug input device without specifying bus

Expected results:
Can plug input device without specifying bus

Upstream issue:
https://gitlab.com/libvirt/libvirt/-/issues/577