migration/postcopy: Add max-postcopy-bandwidth parameter

Limit the background transfer bandwidth during the postcopy
phase to the value set on this new parameter.  The default, 0,
corresponds to the existing behaviour which is unlimited bandwidth.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20180613102642.23995-2-dgilbert@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
3 files changed