When converting a pfn to a physical address be sure to use 64 bit
wide types or convert the physical address to a pfn if possible.
Signed-off-by: Juergen Gross <jgross@suse.com>
Tested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>