Re: [Qemu-devel] [PATCH RFC] hw/pc: set q35 as the default x86 machine

[Marcel Apfelbaum]

On 06/05/2018 11:43 AM, Daniel P. Berrangé wrote:
> On Tue, Jun 05, 2018 at 09:27:46AM +0200, Gerd Hoffmann wrote:
> >    Hi,
> >
> > > >    Add to that shortcuts like -cdrom
> > > > stop working,
> > > Maybe is fixable.
> > Already fixed for ages.
> >
> > > I see marking Q35 as the default machine a first step.
> > 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 notice
> > there is a world beside 'pc', and we also avoid breaking things
> > silently.

It can work, sure. And we can add user hints: "Use q35 for ...., select 
pc if..."

> 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

Can't libvirt preserve 'pc' for existing domains, while defaulting to q35
the creation of new domains ? This way it aligns with Gerd's proposal of 
no default
x86 machine.

Thanks,
Marcel

> Regards,
> Daniel