14.2. Attaching and Updating a Device with virsh

Procedure 14.1. Hot plugging USB devices for use by the guest virtual machine

1. Locate the USB device you want to attach with the following command:

   # lsusb -v
   
   idVendor           0x17ef Lenovo
   idProduct          0x480f Integrated Webcam [R5U877]
   
   

2. Create an XML file and give it a logical name (usb_device.xml, for example). Make sure you copy the vendor and product IDs exactly as was displayed in your search.

   
      <hostdev mode='subsystem' type='usb' managed='yes'>
         <source>
           <vendor id='0x17ef'/>
           <product id='0x480f'/>
         </source>
       </hostdev>
     ...
   
   

   Figure 14.1. USB Devices XML Snippet

3. Attach the device with the following command:

   # virsh attach-device rhel6 --file usb_device.xml --config

   In this example [rhel6] is the name of your guest virtual machine and [usb_device.xml] is the file you created in the previous step. If you want to have the change take effect in the next reboot, use the --config option. If you want this change to be persistent, use the --persistent option. If you want the change to take effect on the current domain, use the --current option. See the Virsh man page for additional information.
4. If you want to detach the device (hot unplug), perform the following command:

   # virsh detach-device rhel6 --file usb_device.xml

   In this example [rhel6] is the name of your guest virtual machine and [usb_device.xml] is the file you attached in the previous step