I’m using Looking-Glass to share my mouse/keyboard/audio between host and client:
https://looking-glass.io/
And USB-Libvirt-Hotplug to pass through USB devices to the KVM on the fly:
https://github.com/olavmrk/usb-libvirt-hotplug
Hope these will prove useful to you :)
Ah sorry that wasn’t clear to me,
thought you where talking about KVMs as in Kernel Virtual Machines :)