Re: [Qemu-devel] [PATCH v2] qom: Introduce object_realize_nofail()

[Anthony Liguori]

On 04/12/2012 11:09 AM, Peter Maydell wrote:
> On 12 April 2012 17:02, Anthony Liguori<address@hidden>  wrote:
> > On 04/12/2012 10:52 AM, Peter Maydell wrote:
> > > Why would you design an infrastructure that lets you coherently bundle
> > > together a collection of devices and have configurable properties on
> > > that bundle as well as on the devices, and then *not* use it for machines?
> >
> >
> > The machine concept in QEMU is "broken" IMHO.  If we want to maintain
> > compatibility (and we do), we need to let machines act as a bridge.
> >
> > Here's how I expect the PC to work:
> >
> > qemu --no-machine -readconfig my-system.cfg
> >
> > [device "root"]
> > driver=i440fx
> > cpu[0]=cpu0
> > slot[3]=e1000
> > memory=2G
> > biosname=bios.bin
> >
> > [device "cpu0"]
> > driver=qemu64
> >
> > [device "e1000"]
> > bus=/i440fx
> > netdev=eth0
> >
> > [netdev "eth0"]
> > type=tap
>
> Isn't this just defining a machine in a config file without
> naming it?

Yup.

And what we think of as "machines' should basically just be doing the same thing 
a config file does.  It doesn't need to be part of the object model.

> > There is no real need to have a '-machine' option and no need to model a
> > machine.
>
> This doesn't make sense to me. We need a -machine option because it's
> the major way for the user to say what kind of model they want. We need
> to model machines because without that we just have a pile of useless
> devices.

Machine wouldn't go away.  The point I'm making is that -machine doesn't have to 
be an alias of a single -device option.

Regards,

Anthony Liguori

> > -M pc ends up being a compatibility bridge which takes a bunch of options
> > that really do lots of different things (like choosing network device
> > models).  I see machines as a function that takes a QemuOpts and then does
> > the equivalent of the above.
>
> -- PMM