From: "Daniel P. Berrangé" <berrange@redhat.com>
To: Andrea Bolognani <abologna@redhat.com>
Cc: Eric Blake <eblake@redhat.com>, Kevin Wolf <kwolf@redhat.com>,
qemu-block@nongnu.org, "Michael S. Tsirkin" <mst@redhat.com>,
qemu-devel@nongnu.org, armbru@redhat.com,
"Dr. David Alan Gilbert" <dgilbert@redhat.com>,
"Richard W.M. Jones" <rjones@redhat.com>,
stefanha@redhat.com, Max Reitz <mreitz@redhat.com>
Subject: Re: [Qemu-devel] storing machine data in qcow images?
Date: Thu, 7 Jun 2018 11:22:57 +0100 [thread overview]
Message-ID: <20180607102257.GH28827@redhat.com> (raw)
In-Reply-To: <f3914a591a46c9d489f2fa1ad2ac4fd0c5a9e5b6.camel@redhat.com>
On Thu, Jun 07, 2018 at 12:02:29PM +0200, Andrea Bolognani wrote:
> On Wed, 2018-06-06 at 17:32 +0100, Daniel P. Berrangé wrote:
> > On Wed, Jun 06, 2018 at 10:36:20AM -0500, Eric Blake wrote:
> > > But for the new config to be useful, you have to modify at least one tool in
> > > the path. At which point, it is just as easy to say: "libvirt is now smart
> > > enough to read the config file out of a .qcow2 to know that it should prefer
> > > a q35 machine" as it is to say "libvirt is now smart enough to treat a .tar
> > > file containing .qcow2 and a config file that states that it should prefer a
> > > q35 machine", and either approach requires just a single file for the user
> > > to download.
> >
> > Just to be clear, libvirt isn't going to do either of those things.
> >
> > Whether there is metadata stuffed inside qcow2, or in a metdata file
> > inside a tar file, libvirt is not going to look inside either of them.
> > The XML is the only place libvirt deals with the hardware config.
> >
> > Extracting machine type is always going to be a job for the layer above
> > such as OpenStack/OVirt/Virt-manager/etc. They will then decide whether
> > or not they want to honour that info, and if so, put it into the XML
> > they give to libvirt.
> >
> > As mentioned elsewhere, IMHO, it is more friendly to those tools
> > to use pre-existing formats, eg TAR and XML/JSON, for which
> > their respective programming langauges already have APIs/parsers.
>
> Something that I haven't seen mentioned in the thread - and this
> looks like as good a point as any to jump in - is that for q35
> guests using EFI as well as aarch64 guests the "one click import"
> experience requires not only hints about the machine (and firmware!)
> type, but also a copy of the EFI variable store:
>
> $ virt-builder fedora-27 --arch aarch64 --notes
> Fedora® 27 Server (aarch64)
>
> [...]
>
> You will need to use the associated UEFI NVRAM variables file:
> http://libguestfs.org/download/builder/fedora-27-aarch64-nvram.xz
>
> While hints might be considered a reasonable fit for qcow2, I think
> it's pretty hard to argue for embedding the NVRAM file in there,
> which to me signals quite clearly that an archive containing the
> disk image(s) *and* the configuration hints *and* other ancillary
> files such as the NVRAM is the only way to build a solution that's
> not dead on arrival.
On a similar theme, I can imagine users wanting to provide a TPM
data blob too, and for AMD SEV we'd need to be able to provide a
DH key, and session blob too IIUC.
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:[~2018-06-07 10:23 UTC|newest]
Thread overview: 157+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-05-18 15:30 [Qemu-devel] storing machine data in qcow images? Michael S. Tsirkin
2018-05-18 16:49 ` Eduardo Habkost
2018-05-18 17:09 ` Daniel P. Berrangé
2018-05-18 17:41 ` Eduardo Habkost
2018-05-19 6:05 ` Markus Armbruster
2018-05-21 18:29 ` Eduardo Habkost
2018-05-21 18:44 ` Daniel P. Berrangé
2018-05-21 19:01 ` Eduardo Habkost
2018-05-23 11:19 ` Markus Armbruster
2018-05-23 12:13 ` Eduardo Habkost
2018-05-23 16:35 ` Markus Armbruster
2018-05-29 14:06 ` Dr. David Alan Gilbert
2018-06-05 21:58 ` Michal Suchánek
2018-05-21 20:18 ` Daniel P. Berrangé
2018-05-21 20:33 ` Eduardo Habkost
2018-05-24 9:58 ` Kashyap Chamarthy
2018-05-22 7:35 ` Gerd Hoffmann
2018-05-22 10:53 ` Eduardo Habkost
2018-05-22 14:19 ` Michael S. Tsirkin
2018-05-22 15:02 ` Kevin Wolf
2018-05-22 15:14 ` Eduardo Habkost
2018-05-23 2:12 ` Fam Zheng
2018-05-23 9:16 ` Kevin Wolf
2018-05-23 14:46 ` Michael S. Tsirkin
2018-05-24 11:17 ` Richard W.M. Jones
2018-05-29 14:03 ` Dr. David Alan Gilbert
2018-05-29 14:14 ` Eduardo Habkost
2018-05-29 14:51 ` Richard W.M. Jones
2018-05-29 15:31 ` Dr. David Alan Gilbert
2018-05-22 8:50 ` Philipp Hahn
2018-05-24 11:32 ` Richard W.M. Jones
2018-05-24 14:56 ` Michael S. Tsirkin
2018-05-24 15:08 ` Kevin Wolf
2018-05-24 15:19 ` Michael S. Tsirkin
2018-05-24 15:20 ` Richard W.M. Jones
2018-05-24 16:25 ` Markus Armbruster
2018-05-28 18:10 ` Max Reitz
2018-05-28 18:30 ` Richard W.M. Jones
2018-05-28 18:38 ` Kevin Wolf
2018-05-28 18:44 ` Max Reitz
2018-05-28 19:09 ` Kevin Wolf
2018-05-29 9:23 ` Max Reitz
2018-05-29 10:14 ` Kevin Wolf
2018-05-29 13:16 ` Eduardo Habkost
2018-05-28 21:20 ` Richard W.M. Jones
2018-05-28 21:25 ` Richard W.M. Jones
2018-05-29 6:44 ` Kevin Wolf
2018-05-29 10:14 ` Max Reitz
2018-06-05 9:21 ` Dr. David Alan Gilbert
2018-06-05 19:03 ` Eduardo Habkost
2018-06-05 19:47 ` Michael S. Tsirkin
2018-06-05 19:54 ` [Qemu-devel] [Qemu-block] " Eric Blake
2018-06-05 19:58 ` Richard W.M. Jones
2018-06-05 20:09 ` Eric Blake
2018-06-05 20:28 ` Michael S. Tsirkin
2018-06-05 20:46 ` Eric Blake
2018-06-05 21:26 ` Michael S. Tsirkin
2018-06-06 8:07 ` Dr. David Alan Gilbert
2018-06-06 6:23 ` Gerd Hoffmann
2018-06-05 20:06 ` Michael S. Tsirkin
2018-06-06 6:26 ` [Qemu-devel] " Gerd Hoffmann
2018-06-06 9:44 ` Dr. David Alan Gilbert
2018-06-06 13:35 ` Eduardo Habkost
2018-06-06 11:02 ` Max Reitz
2018-06-06 11:14 ` Dr. David Alan Gilbert
2018-06-06 11:26 ` Max Reitz
2018-06-06 12:00 ` Dr. David Alan Gilbert
2018-06-06 12:59 ` Max Reitz
2018-06-06 14:31 ` Dr. David Alan Gilbert
2018-06-06 14:37 ` Daniel P. Berrangé
2018-06-06 14:42 ` Dr. David Alan Gilbert
2018-06-06 14:51 ` Max Reitz
2018-06-06 15:05 ` Dr. David Alan Gilbert
2018-06-06 15:36 ` Eric Blake
2018-06-06 16:11 ` Michal Suchánek
2018-06-06 16:37 ` Eric Blake
2018-06-06 16:32 ` Daniel P. Berrangé
2018-06-06 16:36 ` Dr. David Alan Gilbert
2018-06-07 10:02 ` Andrea Bolognani
2018-06-07 10:22 ` Daniel P. Berrangé [this message]
2018-06-07 11:17 ` Andrea Bolognani
2018-06-07 12:38 ` Daniel P. Berrangé
2018-06-07 13:49 ` Dr. David Alan Gilbert
2018-06-07 14:06 ` Andrea Bolognani
2018-06-07 14:45 ` Dr. David Alan Gilbert
2018-06-07 14:56 ` Andrea Bolognani
2018-06-07 15:25 ` Dr. David Alan Gilbert
2018-06-07 20:38 ` Gerd Hoffmann
2018-06-07 10:32 ` Richard W.M. Jones
2018-06-07 10:35 ` Dr. David Alan Gilbert
2018-06-07 10:36 ` Daniel P. Berrangé
2018-06-07 10:54 ` Andrea Bolognani
2018-06-07 19:24 ` Laszlo Ersek
2018-06-08 8:21 ` Dr. David Alan Gilbert
2018-06-08 8:41 ` Daniel P. Berrangé
2018-06-08 8:53 ` Dr. David Alan Gilbert
2018-06-07 21:19 ` Michael S. Tsirkin
2018-06-07 21:18 ` Michael S. Tsirkin
2018-06-07 10:51 ` Andrea Bolognani
2018-06-07 19:38 ` Laszlo Ersek
2018-06-06 17:49 ` Max Reitz
2018-06-06 15:09 ` Michael S. Tsirkin
2018-06-06 17:06 ` Max Reitz
2018-06-07 21:43 ` Michael S. Tsirkin
2018-06-09 21:34 ` Max Reitz
2018-06-11 2:06 ` Michael S. Tsirkin
2018-06-11 8:16 ` Michal Suchánek
2018-06-06 11:42 ` Richard W.M. Jones
2018-06-06 11:48 ` Daniel P. Berrangé
2018-06-06 11:53 ` Max Reitz
2018-06-06 12:03 ` Dr. David Alan Gilbert
2018-06-06 13:15 ` Max Reitz
2018-06-06 12:29 ` Richard W.M. Jones
2018-06-06 11:22 ` [Qemu-devel] [Qemu-block] " Peter Krempa
2018-06-06 10:32 ` [Qemu-devel] " Michal Suchánek
2018-06-06 11:02 ` Max Reitz
2018-06-06 11:19 ` Michal Suchánek
2018-06-06 11:32 ` Max Reitz
2018-06-06 11:37 ` Dr. David Alan Gilbert
2018-06-06 11:44 ` Max Reitz
2018-06-06 12:16 ` Dr. David Alan Gilbert
2018-06-06 13:22 ` Max Reitz
2018-06-06 14:02 ` Dr. David Alan Gilbert
2018-06-06 14:33 ` Max Reitz
2018-06-06 14:41 ` Dr. David Alan Gilbert
2018-06-06 14:55 ` Max Reitz
2018-06-06 15:25 ` Michal Suchánek
2018-06-06 18:02 ` Max Reitz
2018-06-06 18:33 ` Michal Suchánek
2018-06-06 18:36 ` Eduardo Habkost
2018-06-07 18:27 ` [Qemu-devel] [Qemu-block] " Kashyap Chamarthy
2018-06-06 13:42 ` [Qemu-devel] " Eduardo Habkost
2018-06-06 14:55 ` Michael S. Tsirkin
2018-06-06 14:57 ` Max Reitz
2018-06-11 14:10 ` Kevin Wolf
2018-06-06 14:46 ` Michael S. Tsirkin
2018-06-06 15:04 ` Max Reitz
2018-06-06 11:43 ` Michal Suchánek
2018-06-06 11:52 ` Max Reitz
2018-06-06 12:13 ` Michal Suchánek
2018-06-06 13:14 ` Max Reitz
2018-06-06 13:45 ` Michal Suchánek
2018-06-06 13:50 ` Daniel P. Berrangé
2018-06-06 14:14 ` Eduardo Habkost
2018-06-06 14:21 ` Max Reitz
2018-06-06 14:24 ` Daniel P. Berrangé
2018-06-06 14:17 ` Max Reitz
2018-06-06 16:10 ` Eduardo Habkost
2018-06-06 18:09 ` Max Reitz
2018-06-11 8:44 ` Richard W.M. Jones
2018-06-06 11:40 ` Richard W.M. Jones
2018-06-06 14:31 ` Michael S. Tsirkin
2018-06-06 14:43 ` Michael S. Tsirkin
2018-06-06 14:57 ` Eric Blake
2018-06-06 20:39 ` Eric Blake
2018-06-06 21:01 ` Gerd Hoffmann
2018-06-06 15:02 ` Max Reitz
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=20180607102257.GH28827@redhat.com \
--to=berrange@redhat.com \
--cc=abologna@redhat.com \
--cc=armbru@redhat.com \
--cc=dgilbert@redhat.com \
--cc=eblake@redhat.com \
--cc=kwolf@redhat.com \
--cc=mreitz@redhat.com \
--cc=mst@redhat.com \
--cc=qemu-block@nongnu.org \
--cc=qemu-devel@nongnu.org \
--cc=rjones@redhat.com \
--cc=stefanha@redhat.com \
/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).