[libvirt] [PATCH 6/8] qemu_driver: add support to perf event

[Jiri Denemark]

On Mon, Nov 30, 2015 at 08:17:05 +0000, Ren, Qiaowei wrote:
> 
> > -----Original Message-----
> > From: Jiri Denemark [mailto:jdenemar at redhat.com]
> > Sent: Tuesday, November 24, 2015 9:01 PM
> > To: Ren, Qiaowei
> > Cc: libvir-list at redhat.com
> > Subject: Re: [libvirt] [PATCH 6/8] qemu_driver: add support to perf event
> > 
> > On Tue, Nov 17, 2015 at 16:00:46 +0800, Qiaowei Ren wrote:
> > > This patch implement the internal driver API for perf event into qemu
> > > driver.
> > >
> > > In addition, this patch extend virDomainListGetStats API to get the
> > > statistics for perf event. To do so, we add a 'VIR_DOMAIN_STATS_PERF'
> > > enum to causes reporting of all previously enabled perf events.
> > >
> > > Signed-off-by: Qiaowei Ren <qiaowei.ren at intel.com>
> > > ---
> > >  include/libvirt/libvirt-domain.h |   1 +
> > >  src/qemu/qemu_domain.h           |   3 +
> > >  src/qemu/qemu_driver.c           | 181
> > +++++++++++++++++++++++++++++++++++++++
> > >  #define QEMU_SCHED_MIN_PERIOD              1000LL
> > >  #define QEMU_SCHED_MAX_PERIOD           1000000LL
> > >  #define QEMU_SCHED_MIN_QUOTA               1000LL
> > > @@ -10244,6 +10247,106 @@
> > qemuDomainGetNumaParameters(virDomainPtr
> > > dom,  }
> > >
> > >  static int
> > > +qemuDomainSetPerfEvents(virDomainPtr dom,
> > > +                        virTypedParameterPtr params,
> > > +                        int nparams)
> > > +{
> > > +    size_t i;
> > > +    virDomainObjPtr vm = NULL;
> > > +    qemuDomainObjPrivatePtr priv;
> > > +    int ret = -1;
> > > +    bool enabled;
> > > +
> > > +    if (virTypedParamsValidate(params, nparams,
> > > +                               VIR_DOMAIN_PERF_CMT,
> > > +                               VIR_TYPED_PARAM_BOOLEAN,
> > > +                               NULL) < 0)
> > > +        return -1;
> > 
> > Use virTypedParamsCheck and define the data for it in virperf.h so that you
> > don't need to change the code here if new event type is added.
> > 
> 
> Jirka, I checked the difference between virTypedParamsValidate and
> virTypedParamsCheck, and found that virTypedParamsCheck just check
> whether the param is valid through param name, but
> virTypedParamsValidate will check whether the param type is right.

Oh, sorry for the confusion then. I actually wanted the code to be
something like

    if (virTypedParamsValidate(params, nparams, VIR_PERF_PARAMS) < 0)
        return -1;

and VIR_PERF_PARAMS would be a macro defined in virparams.h:

# define VIR_PERF_PARAMS \
    VIR_DOMAIN_PERF_CMT, VIR_TYPED_PARAM_BOOLEAN, \
    NULL

Similar to QEMU_MIGRATION_PARAMETERS and few others.

Jirka