qemu-devel.nongnu.org archive mirror
 help / color / mirror / Atom feed
From: Paul Brook <paul@codesourcery.com>
To: Filip Navara <filip.navara@gmail.com>
Cc: qemu-devel@nongnu.org, Gleb Natapov <gleb@redhat.com>
Subject: Re: [Qemu-devel] [PATCH v2] make windows notice media change
Date: Wed, 29 Jul 2009 21:05:18 +0100	[thread overview]
Message-ID: <200907292105.19006.paul@codesourcery.com> (raw)
In-Reply-To: <5b31733c0907291256r734416d2ifbe8b72105eba27c@mail.gmail.com>

> >> BTW, why would there be the version parameter in the first place if it
> >> wasn't supposed to load older versions?!
> >
> > Like I already said: it's there to prevent an old version being loaded
> > accidentally. Without this an incompatible change will  result in
> > anything from a crash to corrupt/inconsistent guest state. Versioning
> > allows us to reject the snapshot and fail safely.
>
> If that was the case then the if (version != x) return -EINVAL check could
> have been in the generic code and there would be no need for the version
> parameter in the load function.

Preventing loading bad snapshots is the primary goal.

Allowing loading old snapshots is a secondary feature. Personally I think it's 
not worth the effort, and in practice is unlikely to be feasible for whole 
machines over any significant length of time. However I don't feel strongly 
enough to actually rip the code out.

Paul

  reply	other threads:[~2009-07-29 20:05 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-07-29 12:07 [Qemu-devel] [PATCH] make windows notice media change Gleb Natapov
2009-07-29 13:50 ` [Qemu-devel] [PATCH v2] " Gleb Natapov
2009-07-29 14:22   ` Avi Kivity
2009-07-29 14:21     ` Gleb Natapov
2009-07-29 14:44       ` Avi Kivity
2009-07-29 14:35   ` Filip Navara
2009-07-29 14:40     ` Gleb Natapov
2009-07-29 14:59       ` Stefano Stabellini
2009-07-29 19:11     ` Paul Brook
2009-07-29 19:18       ` Filip Navara
2009-07-29 19:24         ` Filip Navara
2009-07-29 19:34           ` Anthony Liguori
2009-07-29 19:52           ` Paul Brook
2009-07-29 19:56             ` Filip Navara
2009-07-29 20:05               ` Paul Brook [this message]
2009-07-29 20:14                 ` Gleb Natapov
2009-07-30 12:14                 ` Stefano Stabellini
2009-07-30 12:27                   ` Paul Brook
2009-07-29 19:33     ` Anthony Liguori
2009-07-29 19:44       ` [Qemu-devel] " Juan Quintela
2009-07-29 20:05         ` Anthony Liguori
2009-07-29 20:09           ` Juan Quintela

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=200907292105.19006.paul@codesourcery.com \
    --to=paul@codesourcery.com \
    --cc=filip.navara@gmail.com \
    --cc=gleb@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).