The balloon device is used to take regions of unused memory from the
guest and allow other host processes to use that memory.
Change-Id: I06c821365a58672d605fc7555beaec599cae1b15
Signed-off-by: Dylan Reid <dgreid@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/759306
Reviewed-by: Stephen Barber <smbarber@chromium.org>