From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760568Ab3B1VNg (ORCPT ); Thu, 28 Feb 2013 16:13:36 -0500 Received: from mx1.redhat.com ([209.132.183.28]:10476 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751509Ab3B1VNe (ORCPT ); Thu, 28 Feb 2013 16:13:34 -0500 Message-ID: <512FC845.9080209@redhat.com> Date: Thu, 28 Feb 2013 14:12:37 -0700 From: Eric Blake Organization: Red Hat, Inc. User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130219 Thunderbird/17.0.3 MIME-Version: 1.0 To: Hu Tao CC: kvm list , qemu-devel , "linux-kernel@vger.kernel.org" , "Daniel P. Berrange" , KAMEZAWA Hiroyuki , Jan Kiszka , Gleb Natapov , Blue Swirl , Andrew Jones , Marcelo Tosatti , Sasha Levin , Luiz Capitulino , Anthony Liguori , Markus Armbruster , Paolo Bonzini , Stefan Hajnoczi , Juan Quintela , Orit Wasserman , Kevin Wolf , Wen Congyang , "Michael S. Tsirkin" , Alexander Graf , Alex Williamson , Peter Maydell Subject: Re: [PATCH v13 1/8] save/load cpu runstate References: In-Reply-To: X-Enigmail-Version: 1.5.1 OpenPGP: url=http://people.redhat.com/eblake/eblake.gpg Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="----enig2KGFPHESTKVMQPNTPCTHU" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This is an OpenPGP/MIME signed message (RFC 4880 and 3156) ------enig2KGFPHESTKVMQPNTPCTHU Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On 02/28/2013 05:13 AM, Hu Tao wrote: > This patch enables preservation of cpu runstate during save/load vm. > So when a vm is restored from snapshot, the cpu runstate is restored, > too. What happens if a management app wants to override the runstate when restoring the domain? I can think of several useful scenarios: 1. management app pauses the guest, then saves domain state and other things (management state, or disk clones), then resumes the guest. Later, the management wants to revert to the saved state, but have the guest running right away. I guess here, knowing that the guest was saved in a paused state doesn't hurt, since the management app can resume it right away. 2. management app saves domain state of a live guest, then copies that state elsewhere. In its new location, the management app wants to investigate the state for forensic analysis - so even though the guest remembers that it was running, management wants to start it paused. Here, it is important that there must not be a window of time where the guest can run, otherwise, the results are not reproducible. --=20 Eric Blake eblake redhat com +1-919-301-3266 Libvirt virtualization library http://libvirt.org ------enig2KGFPHESTKVMQPNTPCTHU Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.13 (GNU/Linux) Comment: Public key at http://people.redhat.com/eblake/eblake.gpg Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iQEcBAEBCAAGBQJRL8hFAAoJEKeha0olJ0NqiqIH/jhEaYxoEOF5ai1k7Clr+gUZ wxoQtCASSj4t4JsxpNjAWyDwePtM3lT+E1tiVsgsoCJgc1XcPrYFrLU80NXPo+6u 1BgkqAHsxbRNybLBN458jkWgN/d2ZAplyLbAgCeVfmOTcbTwK3lAqI0rVu3Rh9OQ 6MfagF2WQc/pTqdc90TadtDq3CSQmt5QoW1anzXy8f9NSdUO69w/ZCjbMPm8PMfR wg++5FavuFQoa/MqUWnK9U/igAww7Qloru13Lp3EV3rMxySSJyu4OaZPcNg7390T WKheOYEn/W1DC17aTqEmoN3+Tq34FZUln0rv42176Z+foc4x2Qcim2hIPLSI39E= =+51e -----END PGP SIGNATURE----- ------enig2KGFPHESTKVMQPNTPCTHU--