From: "Daniel P. Berrangé" <berrange@redhat.com>
To: Eric Blake <eblake@redhat.com>
Cc: libvir-list@redhat.com, Igor Mammedov <imammedo@redhat.com>,
qemu-devel@nongnu.org, dgilbert@redhat.com, ehabkost@redhat.com
Subject: Re: [Qemu-devel] [libvirt] [PATCH v2] deprecate -mem-path fallback to anonymous RAM
Date: Tue, 25 Jun 2019 19:27:55 +0100 [thread overview]
Message-ID: <20190625182755.GN3139@redhat.com> (raw)
In-Reply-To: <2647871f-34f2-0f8d-adb7-0265f951acd3@redhat.com>
On Tue, Jun 25, 2019 at 01:18:01PM -0500, Eric Blake wrote:
> On 6/25/19 11:16 AM, Igor Mammedov wrote:
> > Fallback might affect guest or worse whole host performance
> > or functionality if backing file were used to share guest RAM
> > with another process.
> >
> > Patch deprecates fallback so that we could remove it in future
> > and ensure that QEMU will provide expected behavior and fail if
> > it can't use user provided backing file.
> >
> > Signed-off-by: Igor Mammedov <imammedo@redhat.com>
> > ---
> > v2:
> > * improve text language
> > (Markus Armbruster <armbru@redhat.com>)
> >
>
> Is this deprecation introspectible? Does it need to be?
>
> Do we even need a deprecation period, or can we declare this a bug fix
> (it was a bug that we didn't fail outright on an impossible request) and
> do it immediately?
I think it is hard to call it a bug when we added explicit extra code to
make it work as it does today.
It is really a misguided feature.
> If it is not a bug fix, perhaps it could be made introspectible by
> having a new boolean parameter to opt in to the failure now, rather than
> 2 releases from now?
From libvirt's POV I don't see a need for introspection. There's no
special action we need to take to deal with the new behaviour - it is
ultimately just providing the behaviour we kind of assumed it already
had.
Regards,
Daniel
--
|: https://berrange.com -o- https://www.flickr.com/photos/dberrange :|
|: https://libvirt.org -o- https://fstop138.berrange.com :|
|: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|
next prev parent reply other threads:[~2019-06-25 18:30 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-25 16:16 [Qemu-devel] [PATCH v2] deprecate -mem-path fallback to anonymous RAM Igor Mammedov
2019-06-25 16:44 ` Daniel P. Berrangé
2019-06-25 18:18 ` [Qemu-devel] [libvirt] " Eric Blake
2019-06-25 18:27 ` Daniel P. Berrangé [this message]
2019-06-26 5:02 ` [Qemu-devel] " 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=20190625182755.GN3139@redhat.com \
--to=berrange@redhat.com \
--cc=dgilbert@redhat.com \
--cc=eblake@redhat.com \
--cc=ehabkost@redhat.com \
--cc=imammedo@redhat.com \
--cc=libvir-list@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).