Original patch from Ulrich Hecht, further work from Alexander Graf
and Richard Henderson.

Cc: Ulrich Hecht <uli@suse.de>
Cc: Alexander Graf <agraf@suse.de>
Signed-off-by: NRichard Henderson <rth@twiddle.net>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>