From: Eric Blake <eblake@redhat.com>
To: Luiz Capitulino <lcapitulino@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>,
Markus Armbruster <armbru@redhat.com>,
qemu-devel <qemu-devel@nongnu.org>
Subject: Re: [Qemu-devel] qmp: dump-guest-memory: -p option has issues, fix it or drop it?
Date: Mon, 17 Sep 2012 12:08:28 -0600 [thread overview]
Message-ID: <5057671C.40400@redhat.com> (raw)
In-Reply-To: <20120917145622.5ba28e23@doriath.home>
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On 09/17/2012 11:56 AM, Luiz Capitulino wrote:
> Hi Wen,
>
> We've re-reviewed the dump-guest-memory command and found some
> possible issues with the -p option.
>
> However, I also think that we should consider if having the -p
> feature is really worth it. It's a complex feature and has a number
> of limitations*. If libvirt doesn't use this, dropping it shouldn't
> be a big deal (we can return an error when -p is used).
>
> * The issues discussed in this email plus the fact that the guest
> memory may be corrupted, and the guest may be in real-mode even
> when paging is enabled
Libvirt is not currently exposing the -p mode (that is, it currently
blindly passes 'paging':false to the JSON command). Dropping it would
have no noticeable impact to libvirt. (Note - libvirt _did_ wire up an
internal flag to qemu_monitor_json.c, QEMU_MONITOR_DUMP_PAGING, but
nothing sets this flag, so libvirt would need a cleanup patch to remove
it as useless code, but that is not user-visible.)
--
Eric Blake eblake@redhat.com +1-919-301-3266
Libvirt virtualization library http://libvirt.org
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next prev parent reply other threads:[~2012-09-17 18:08 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-09-17 17:56 [Qemu-devel] qmp: dump-guest-memory: -p option has issues, fix it or drop it? Luiz Capitulino
2012-09-17 18:08 ` Eric Blake [this message]
2012-09-18 1:52 ` Wen Congyang
2012-09-18 9:22 ` Jan Kiszka
2012-09-18 12:23 ` Markus Armbruster
2012-09-18 12:41 ` Jan Kiszka
2012-09-18 13:33 ` Luiz Capitulino
2012-09-18 16:51 ` Jan Kiszka
2012-09-18 13:36 ` Markus Armbruster
2012-09-18 21:13 ` Anthony Liguori
2012-09-19 0:18 ` Luiz Capitulino
2012-09-19 0:56 ` Anthony Liguori
2012-09-19 2:07 ` Wen Congyang
2012-09-19 2:26 ` HATAYAMA Daisuke
2012-09-19 13:23 ` Luiz Capitulino
2012-09-20 1:06 ` HATAYAMA Daisuke
2012-09-19 7:25 ` Markus Armbruster
2012-09-19 12:10 ` Anthony Liguori
2012-09-19 13:13 ` Markus Armbruster
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