From mboxrd@z Thu Jan  1 00:00:00 1970
From: Olaf Hering <olaf@aepfle.de>
Subject: Re: [PATCH v4 0/9] toolstack-based approach to pvhvm
 guest kexec
Date: Thu, 11 Dec 2014 15:24:28 +0100
Message-ID: <20141211142428.GA19820@aepfle.de>
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To: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Wei Liu <wei.liu2@citrix.com>, Andrew Jones <drjones@redhat.com>, Keir Fraser <keir@xen.org>, Ian Campbell <ian.campbell@citrix.com>, Stefano Stabellini <stefano.stabellini@eu.citrix.com>, Andrew Cooper <andrew.cooper3@citrix.com>, Ian Jackson <ian.jackson@eu.citrix.com>, Tim Deegan <tim@xen.org>, David Vrabel <david.vrabel@citrix.com>, Jan Beulich <jbeulich@suse.com>, xen-devel@lists.xenproject.org
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On Wed, Dec 03, Vitaly Kuznetsov wrote:

> When a PVHVM linux guest performs kexec there are lots of things which
> require taking care of:
> - shared info, vcpu_info
> - grants
> - event channels
> - ...
> Instead of taking care of all these things we can rebuild the domain
> performing kexec from scratch doing so-called soft-reboot.

How does this approach handle ballooned pages?
>>From the guests point of view they are always there, just claimed by the
balloon driver. The new kernel does not have that driver nor does its
driver have the knowledge which pages the old kernel gave back to Xen.

After a brief look none of the patches seem to deal with that.

Olaf