From mboxrd@z Thu Jan  1 00:00:00 1970
From: David Vrabel <david.vrabel@citrix.com>
Subject: Re: Migration memory corruption - PV backends need to
	quiesce
Date: Fri, 27 Jun 2014 18:28:08 +0100
Message-ID: <53ADA9A8.6020103@citrix.com>
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To: Andrew Cooper <andrew.cooper3@citrix.com>, Xen-devel List <xen-devel@lists.xen.org>
Cc: Ian Campbell <Ian.Campbell@citrix.com>, Tim Deegan <tim@xen.org>, Ian Jackson <Ian.Jackson@eu.citrix.com>, Paul Durrant <Paul.Durrant@citrix.com>, Jan Beulich <JBeulich@suse.com>
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On 27/06/14 17:51, Andrew Cooper wrote:
> 
> Overall, it would appear that there needs to be a hook for all PV
> drivers to force quiescence.  In particular, a backend must guarantee to
> unmap all active grant maps (so the frames get properly reflected in the
> dirty bitmap), and never process subsequent requests (so no new frames
> appear dirty in the bitmap after the guest has been paused).

I think this would be much too expensive for snapshots and things like
remus.  Waiting for all outstanding I/O could take seconds.

David