>>> Ian Campbell  07/13/11 11:12 AM >>>
>It's not so much an objection to this patch but this issue seems to have
>been caused by Xen cset 20892:d311d1efc25e which looks to me like a
>subtle ABI breakage for guests. Perhaps we should introduce a feature
>flag to indicate that a guest can cope with the m2p changing size over
>migration like this?

Indeed - migration was completely beyond my consideration when
submitting this. A feature flag seems the right way to go to me.

Jan