Re: [Qemu-devel] [PATCH v6 04/17] Extend HMP command info cpus to display accelerator id and model name

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

On Wed, 6 May 2015 10:33:55 -0300
Eduardo Habkost <ehabkost@redhat.com> wrote:

> On Wed, May 06, 2015 at 08:59:56AM -0400, Luiz Capitulino wrote:
> > On Wed, 6 May 2015 07:38:53 -0300
> > Eduardo Habkost <ehabkost@redhat.com> wrote:
> > 
> > > On Wed, May 06, 2015 at 09:32:58AM +0200, Michael Mueller wrote:
> > > > On Tue, 5 May 2015 10:14:32 -0300
> > > > Eduardo Habkost <ehabkost@redhat.com> wrote:
> > > > 
> > > > > On Mon, Apr 27, 2015 at 04:53:18PM +0200, Michael Mueller wrote:
> > > > > > The HMP command info cpus now displays the CPU model name and the
> > > > > > backing accelerator if part of the CPUState.
> > > > > > 
> > > > > > (qemu) info cpus
> > > > > > * CPU #0: (halted) model=2827-ga2 accel=kvm thread_id=1679
> > > > > > 
> > > > > > Signed-off-by: Michael Mueller <mimu@linux.vnet.ibm.com>
> > > > > > Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
> > > > > 
> > > > > Do we really need this? I mean: I expect the amount of CPU data we
> > > > > provide to QMP clients to grow a lot in the near future, but that
> > > > > doesn't mean HMP users need all that data to be printed by "info cpus".
> > > > 
> > > > Where do you see the limit of what is worth to be shown an what not.
> > > > I personally use "info cpus" less then sporadic but already got a comment
> > > > internally on that information being worthwhile to be shown.  
> > > 
> > > I really don't know, but I think we shouldn't add stuff to HMP unless we
> > > have a good reason. For each new piece of data in HMP I would like to at
> > > least see the description of a real use case that justifies adding it to
> > > HMP and not just implementing a simple script on top of QMP.
> > > 
> > > For accel info we already have "info kvm" that is not ideal but is
> > > enough for current use cases, isn't it? CPU model name information seems
> > > to be more useful, but if it is just for debugging, people can just run
> > > QMP query-cpus command.
> > > 
> > > Luiz, what do you think?
> > 
> > I don't see a problem with that. HMP is a debugging interface anyways.
> > Actually, I think it's a good test-case for QMP having a high-level
> > in-tree client (vs. qmp-shell, which is too low-level).
> > 
> > If the problem is that a command is dumping too much information to
> > the point of hurting usability, we can split the command or add a '-a'
> > option or something like that.
> 
> Thanks! If HMP is seen as a debugging interface, my main objections
> aren't valid.
> 
> That said, I would prefer to keep the command output cleaner and add
> only the "model" field, as people can use "info kvm" for the accel info
> by now.

Ok, I buy that and will kick the accel name out again.

Michael

>