The virtio device lifecycle can be observed by looking at the sequence
of set status operations.  This is especially important for catching the
reset operation (status value 0), which resets the device and all
virtqueues.
Signed-off-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: NBlue Swirl <blauwirbel@gmail.com>