Nova/USB device hot cold plug

USB device hot/cold plug features

Background

Adding usb devices to a exist vm is a necessary supplement features to usb device passthrough.

User scenarios

When a user transfers money online, him may need to attach a usb-key provided by bank to vm for authentication.

Technical verification

1. Test case

   (1)Attaching different type and number usb controllers and usb devices to vm when vm in diffrent status(running, stopped and so on).
   (2)Detaching usb devices from vm when vm in diffrent status(running, stopped and so on).

2. Xml definition

   (1)Sample of usb controller:
  <controller type='usb' index='2' model='piix3-uhci'/>
  <controller type='usb' index='1' model='ehci'/>

  (2)Sample of pass-through usb devices
  <hostdev mode='subsystem' type='usb'>
   < source>
    <vendor id='0x136b'/>
    <product id='0x0003'/>
    <address bus='2' device='2'/>
   </source>
   <address type='usb' bus='1' port='1'/>
  </hostdev>

3. The test results

Proposed solution

1. Use cases

2. System requirements and things should be considered(An optional Implementation):