On Wed, Feb 25, 2015 at 04:52:02PM +0000, Dr. David Alan Gilbert (git) wrote:
> From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
> 
> Prior to the start of postcopy, ensure that everything that will
> be transferred later is a whole host-page in size.
> 
> This is accomplished by discarding partially transferred host pages
> and marking any that are partially dirty as fully dirty.

Again, I wonder if this might be a bit more obvious with
send/receive_host_page() helpers.  Rather than jiggering the basic
data structures, you make the code only do the transmission in terms
of host page sized chunks, doing the dirty check against all the
necessary target page bits.

Or better yet, a migration_chunk_size variable, rather than host page
size.  Initially that would be initialized to host page size, but
gives easier flexibility to improve future handling of cases where
source hps != dest hps.

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson