Re: [Qemu-devel] [PATCH v4 11/15] target-s390x: New QMP command query-cpu-model

[Michael Mueller <mimu@linux.vnet.ibm.com>]

On Mon, 30 Mar 2015 17:17:21 -0300
Eduardo Habkost <ehabkost@redhat.com> wrote:

> On Mon, Mar 30, 2015 at 04:28:24PM +0200, Michael Mueller wrote:
> > This patch implements a new QMP request named 'query-cpu-model'.
> > It returns the cpu model of cpu 0 and its backing accelerator.
> > 
> > request:
> >   {"execute" : "query-cpu-model" }
> > 
> > answer:
> >   {"return" : {"name": "2827-ga2", "accel": "kvm" }}
> 
> If you are returning information about an existing CPU, why not just
> extend the output of "query-cpus"?
> 
> (Existing qmp_query_cpus() calls cpu_synchronize_state(), which may be
> undesired. But in this case we could add an optional parameter to
> disable the return of data that requires stopping the VCPU).

Will the cpu_cpu_syncronize_state() really hurt in real life? query-cpus will be called only once
a while...

I will prepare the extension of query-cpus as an option but initially without the optional
parameter.

> 
> > 
> > Alias names are resolved to their respective machine type and GA names
> > already during cpu instantiation. Thus, also a cpu model like 'host'
> > which is implemented as alias will return its normalized cpu model name.
> > 
> > Furthermore the patch implements the following function:
> > 
> > - s390_cpu_models_used(), returns true if S390 cpu models are in use
> > 
> > Signed-off-by: Michael Mueller <mimu@linux.vnet.ibm.com>
> [...]
> 

Thanks,
Michael