Re: [Qemu-devel] [libvirt] [PATCH 7/9] qmp: Add runnability information to query-cpu-definitions

[Eduardo Habkost]

On Thu, May 12, 2016 at 09:19:48AM +0200, Jiri Denemark wrote:
> On Wed, May 11, 2016 at 16:35:50 -0300, Eduardo Habkost wrote:
> > # @CpuDefinitionInfo:
> > #
> > # Virtual CPU definition.
> > #
> > # @name: the name of the CPU definition
> > # @runnable: #optional. whether the CPU model us usable with the
> 
> s/ us / is /

Thanks!

> 
> > #            current machine and accelerator. Omitted if we don't
> > #            know the answer. (since 2.7)
> > # @unavailable-features: List of attributes that prevent the CPU
> > #                        model from running in the current host.
> > #                        (since 2.7)
> > #
> > # @unavailable-features is a list of QOM property names that
> > # represent CPU model attributes that prevent the CPU from running.
> > # If the QOM property is read-only, that means the CPU model can
> > # never run in the current host. If the property is read-write, it
> > # means that it MAY be possible to run the CPU model in the current
> > # host if that property is changed. Management software can use it
> > # as hints to suggest or choose an alternative for the user, or
> > # just to generate meaningful error messages explaining why the CPU
> > # model can't be used.
> 
> Any chance this could be extended to provide data about every single
> machine type rather than just the current one?

I want to do that, but it would require reorganizing
CPU/machine/accelerator code to allow probing to happen without
depending on global data (including: machine state, accelerator
state, global properties). This will probably take a while to be
implemented.

But: at least for x86, we now guarantee that runnability
shouldn't change depending on the machine-type. If a CPU model is
runnable with a machine version, it should be runnable with other
versions of the same family.

That guarantee is not documented above because I still don't know
if we can enforce it on all other architectures.

-- 
Eduardo