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Date: Wed, 13 Jun 2018 15:05:08 -0300
From: Eduardo Habkost <ehabkost@redhat.com>
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Subject: Re: [Qemu-devel] [PATCH RFC] hw/pc: set q35 as the default x86
 machine
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To: Daniel =?iso-8859-1?Q?P=2E_Berrang=E9?= <berrange@redhat.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>, "Michael S. Tsirkin" <mst@redhat.com>, qemu-devel@nongnu.org, pbonzini@redhat.com, rth@twiddle.net, libvir-list@redhat.com

Getting back to this discussion:

On Tue, Jun 05, 2018 at 09:43:00AM +0100, Daniel P. Berrang=E9 wrote:
> On Tue, Jun 05, 2018 at 09:27:46AM +0200, Gerd Hoffmann wrote:
> >   Hi,
> >=20
> > > >   Add to that shortcuts like -cdrom
> > > > stop working,
> > >=20
> > > Maybe is fixable.
> >=20
> > Already fixed for ages.
> >=20
> > > I see marking Q35 as the default machine a first step.
> >=20
> > Maybe the better option is to go the arm route:  Just don't define a
> > default, so users have to specify pc or q35.  That will make them not=
ice
> > there is a world beside 'pc', and we also avoid breaking things
> > silently.
>=20
> If QEMU removes the default, then libvirt will have to hardcode
> 'pc' as the default to maintain back compatibility, so I don't
> think that ends up as a net win

I believe there's consensus that applications blindly relying on
the default machine-type when creating a domain is a bad idea.

That said, can we deprecate this feature in libvirt, encourage
applications to always specify an explicit machine-type, thus
making it possible to deprecate the i440fx machine-types one day?

--=20
Eduardo