Exclusive USB Device Passthrough QEMU/KVM

List the device you would like to redirect using lsusb

[user@hostname ~]$ lsusb
Bus 001 Device 004: ID 258a:0027 SINOWEALTH Wired Gaming Mouse

Add the following to your virtsh edit XML file

<hostdev mode='subsystem' type='usb' managed='yes'>
<source>
<address bus='1' device='4'/>
</source>
</hostdev>

Disconnecting the device from your Virtual Machine will reconnect it to the source system.