From: Eduardo Habkost <ehabkost@redhat.com>
To: Sergio Lopez <slp@redhat.com>
Cc: peter.maydell@linaro.org, qemu-devel@nongnu.org,
"Michael S. Tsirkin" <mst@redhat.com>
Subject: Re: [Qemu-devel] [RFC] virtio-mmio: implement modern (v2) personality (virtio-1)
Date: Wed, 31 Jul 2019 18:22:52 -0300 [thread overview]
Message-ID: <20190731212252.GW4313@habkost.net> (raw)
In-Reply-To: <87ftmmwg0e.fsf@redhat.com>
On Wed, Jul 31, 2019 at 02:22:09PM +0200, Sergio Lopez wrote:
>
> Michael S. Tsirkin <mst@redhat.com> writes:
>
> > On Mon, Jul 29, 2019 at 02:57:55PM +0200, Sergio Lopez wrote:
> >> Implement the modern (v2) personality, according to the VirtIO 1.0
> >> specification.
> >>
> >> Support for v2 among guests is not as widespread as it'd be
> >> desirable. While the Linux driver has had it for a while, support is
> >> missing, at least, from Tianocore EDK II, NetBSD and FreeBSD.
> >
> > The fact that there was no open source hypervisor implementation has
> > probably contributed to this :)
> >
> >> For this reason, the v2 personality is disabled, keeping the legacy
> >> behavior as default.
> >
> > I agree it's a good default for existing machine types.
> >
> >> Machine types willing to use v2, can enable it
> >> using MachineClass's compat_props.
> >
> > Hmm. Are compat_props really the recommended mechanism to
> > tweak defaults? I was under the impression it's
> > only for compatibility with old machine types.
> > Eduardo, any opinion on this?
>
> Stefan suggested using something like "-global virtio-mmio.modern=true"
> which does the trick for the command line, but I'd also like a way to
> set it to true by default on microvm. We can discuss the best way to
> achieve that (if using compat_props isn't acceptable) on the next
> microvm patch series.
Compatibility is the most common use case, but IMO compat_props
can be used for other kinds of machine-specific defaults. It's
better than burying defaults inside non-introspectable machine
initialization functions.
--
Eduardo
next prev parent reply other threads:[~2019-07-31 21:23 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-29 12:57 [Qemu-devel] [RFC] virtio-mmio: implement modern (v2) personality (virtio-1) Sergio Lopez
2019-07-29 13:10 ` no-reply
2019-07-30 7:06 ` Stefan Hajnoczi
2019-07-30 8:34 ` Michael S. Tsirkin
2019-07-31 12:22 ` Sergio Lopez
2019-07-31 19:34 ` Michael S. Tsirkin
2019-07-31 21:22 ` Eduardo Habkost [this message]
2019-07-30 10:25 ` Andrea Bolognani
2019-07-30 11:35 ` Cornelia Huck
2019-07-30 12:17 ` Andrea Bolognani
2019-07-30 13:14 ` Cornelia Huck
2019-07-30 20:02 ` Michael S. Tsirkin
2019-07-30 20:18 ` Michael S. Tsirkin
2019-07-31 11:04 ` Sergio Lopez
2019-07-31 13:55 ` Cornelia Huck
2019-07-31 19:06 ` Michael S. Tsirkin
2019-08-01 8:18 ` Cornelia Huck
2019-07-31 11:02 ` Sergio Lopez
2019-08-01 12:17 ` Michael S. Tsirkin
2019-07-30 16:06 ` Laszlo Ersek
2019-07-31 23:58 ` Paolo Bonzini
2019-08-01 19:45 ` Michael S. Tsirkin
2019-08-02 9:24 ` Paolo Bonzini
2019-08-02 0:26 ` Laszlo Ersek
2019-08-02 9:20 ` Peter Maydell
2019-08-02 22:33 ` Laszlo Ersek
2019-08-01 8:37 ` Sergio Lopez
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=20190731212252.GW4313@habkost.net \
--to=ehabkost@redhat.com \
--cc=mst@redhat.com \
--cc=peter.maydell@linaro.org \
--cc=qemu-devel@nongnu.org \
--cc=slp@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).