Re: [Qemu-devel] [PATCH v4 12/15] Add optional parameters to QMP command query-cpu-definitions

[Michael Mueller]

On Tue, 31 Mar 2015 16:46:56 -0300
Eduardo Habkost <address@hidden> wrote:

> On Mon, Mar 30, 2015 at 04:28:25PM +0200, Michael Mueller wrote:
> [...]
> >  ##
> >  # @query-cpu-definitions:
> >  #
> >  # Return a list of supported virtual CPU definitions
> >  #
> > +# @machine: #optional machine type (since 2.4)
> > +#
> > +# @accel: #optional accelerator id (since 2.4)
> > +#
> >  # Returns: a list of CpuDefInfo
> >  #
> >  # Since: 1.2.0
> >  ##
> > -{ 'command': 'query-cpu-definitions', 'returns': ['CpuDefinitionInfo'] }
> > +{ 'command': 'query-cpu-definitions',
> > +  'data': { '*machine': 'str', '*accel': 'AccelId' },
> > +  'returns': ['CpuDefinitionInfo'] }
> 
> What happens if the new parameters are provided to an old QEMU version
> that doesn't accept them? It looks like we need an introspection
> mechanism or a new command name.

Yep, as Eric mentions:

address@hidden (master) qemu]$ sudo virsh qemu-monitor-command zhyp027 '{ 
"execute":
"query-cpu-definitions", "arguments": { "accel": "kvm", "machine":
"s390-ccw-virtio" } }'

{"id":"libvirt-13","error":{"class":"GenericError","desc":"Invalid parameter 
'accel'"}}



>