Pages that have been ballooned are useful for other Xen drivers doing
grant table actions, because these pages have valid struct page/PFNs but
have no valid MFN so are available for remapping.
Acked-by: NIan Campbell <ian.campbell@citrix.com>
Signed-off-by: NDaniel De Graaf <dgdegra@tycho.nsa.gov>
[v2: Deal with rebasing on top of modified balloon code]
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>