qemu-devel.nongnu.org archive mirror
 help / color / mirror / Atom feed
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>

[-- Attachment #1: Type: text/plain, Size: 1136 bytes --]

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


[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 617 bytes --]

  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

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=5057671C.40400@redhat.com \
    --to=eblake@redhat.com \
    --cc=armbru@redhat.com \
    --cc=lcapitulino@redhat.com \
    --cc=mtosatti@redhat.com \
    --cc=qemu-devel@nongnu.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).