Re: [Qemu-devel] [PATCH 3/3 v2] Add a pc-0-10 machine type for compatibility with 0.10.x

[Anthony Liguori]

Gerd Hoffmann wrote:
> On 07/08/09 17:08, Mark McLoughlin wrote:
> > On Wed, 2009-07-08 at 16:09 +0200, Gerd Hoffmann wrote:
> > > > /usr/share/qemu/configs/pc-0-10.dts
> > > > /usr/share/qemu/configs/pc-0-11.dts
> > > > /usr/share/qemu/configs/pc ->  /usr/share/qemu/configs/pc-0-11.dts
> > > Doesn't work.  Your virtio blk device isn't in there.
> >
> > Right - I had assumed Anthony meant that such a config file would also
> > have details on the defaults used for devices which can be added to that
> > machine.
>
> Could probably be done that way, but that wouldn't be different from a 
> global compat variable where the virtio-block-pci driver looks at.
> We have different versions of devices.

We have options that we can tweak for devices.  That doesn't mean 
they're versioned.  What the default set of options that is turned on 
for any given device is determined by the machine type (since the 
machine init is what creates the devices to start with).

Linear versioning doesn't work because there are too many forks of QEMU 
(each distro release that includes backported features is a fork).

Regards.

Anthony Liguori