Re: [Qemu-devel] [PATCH v3 00/26] q35 qemu support

[Michael S. Tsirkin]

On Mon, Oct 22, 2012 at 12:37:39PM +0200, Gerd Hoffmann wrote:
> On 10/22/12 12:08, Michael S. Tsirkin wrote:
> > On Mon, Oct 22, 2012 at 07:58:32AM +0200, Gerd Hoffmann wrote:
> >>   Hi,
> >>
> >>> Would it make sense to temporarily rename the machine type e.g.
> >>> pc-q35-experimental to stress it's not fully supported?
> >>
> >> I don't think this is needed as piix will continue to be the default.
> > 
> > Well q35 is not yet 100% ready.
> 
> I know.
> 
> > The point was to hide it from libvirt.
> > libvirt should support pc-q35 not pc-q35-experimental, then
> > it will not cause trouble.
> 
> You'll not going to hide it that way.  Libvirt will just 'qemu -M ?'
> where q35 will show up even if you rename it to be postfixed -experimental.
> 
> But as long as 'pc' continues to be the default the causal user will
> never ever notice q35 is there, at least not with virt-manager (dunno
> about boxes) as there is simply no gui way to pick the machine type.
> You'll have to explicitly "virsh edit $guest" to switch it to q35.
> 
> So I'm not sure what you are worryed about.

I worry about need to maintain  bug for bug compatibility on the
unlikely chance that the work to complete it gets delayed and we release
it in an unready state.

> But in any case this needs
> discussion with the libvirt folks to make sure it will actually work as
> intended.  /me tends to think a experimental bit in machine_info (which
> is then printed by 'qemu -M ?' and the QOM-version of that) is more
> useful than playing tricks with the name.
> 
> cheers,
>   Gerd

I agree it's best to ask libvirt folks what's the right way to hide
a machine type from it. Add a flag so it's not listed in -M ?  ?
Jason, do you know?

-- 
MST