Description of problem:
Support hotplug/hotunplug to these USB controller/devices:

• nec-usb-xhci
• piix3-usb-uhci
• piix4-usb-uhci
• qemu-xhci
• usb-ehci
• usb-hub
• usb-ccid

Version-Release number of selected component (if applicable):
libvirt-8.7.0-1.el9.x86_64

How reproducible:
100%

Steps to Reproduce:
1. Start an VM
2. Try to attach USB nec-xhci controller/ccid controller/hub:
➜ ~ cat hub.xml
<hub type='usb'/>
➜ ~ virsh attach-device rhel-9.2 hub.xml
error: Failed to attach device from hub.xml
error: Operation not supported: live attach of device 'hub' is not supported

➜ ~ cat nec-xhci.xml
<controller type='usb' index='1' model='nec-xhci'/>
➜ ~ virsh attach-device rhel-9.2 nec-xhci.xml
error: Failed to attach device from nec-xhci.xml
error: Operation not supported: 'usb' controller cannot be hot plugged.

➜ ~ cat ccid.xml
<controller type='ccid' index='0'/>
➜ ~ virsh attach-device rhel-9.2 ccid.xml
error: Failed to attach device from ccid.xml
error: Operation not supported: 'ccid' controller cannot be hot plugged.

In fact, hot-plug for these devices is supported in qemu:
➜ ~ virsh qemu-monitor-command rhel-9.2 '{"execute":"device_add","arguments":{"driver":"usb-hub","bus":"usb.0","port":5,"id":"usb-hub"}}'
{"return":{},"id":"libvirt-574"}
➜ ~ virsh qemu-monitor-command rhel-9.2 '{"execute":"device_del","arguments":{"id":"usb-hub"}}'
{"return":{},"id":"libvirt-575"}

➜ ~ virsh qemu-monitor-command rhel-9.2 '{"execute":"device_add","arguments":{"driver":"usb-ccid","bus":"usb.0","port":5,"id":"usb-ccid"}}'
{"return":{},"id":"libvirt-576"}
➜ ~ virsh qemu-monitor-command rhel-9.2 '{"execute":"device_del","arguments":{"id":"usb-ccid"}}'
{"return":{},"id":"libvirt-577"}

Run hcis.sh to get all the USB controllers with hot-plug/hot-unplug support:
➜ ~ bash /tmp/hcis.sh
...
Hotplug/Hotunplug nec-usb-xhci
{"return":{},"id":"libvirt-594"}

{"return":{},"id":"libvirt-595"}

Hotplug/Hotunplug piix3-usb-uhci
{"return":{},"id":"libvirt-596"}

{"return":{},"id":"libvirt-597"}

Hotplug/Hotunplug piix4-usb-uhci
{"return":{},"id":"libvirt-598"}

{"return":{},"id":"libvirt-599"}

Hotplug/Hotunplug qemu-xhci
{"return":{},"id":"libvirt-600"}

{"return":{},"id":"libvirt-601"}

Hotplug/Hotunplug usb-ehci
{"return":{},"id":"libvirt-602"}

{"return":{},"id":"libvirt-603"}

Actual results:
As above

Expected results:
Support hotplug/hotunplug for the devices mentioned in the subject

Additional info:
See the VM XML and hcis.sh in the attachment