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> -----Original Message-----
> From: Jan Beulich <jbeul...@suse.com>
> Sent: Thursday, August 28, 2025 2:38 PM
> To: Penny, Zheng <penny.zh...@amd.com>
> Cc: Huang, Ray <ray.hu...@amd.com>; Anthony PERARD
> <anthony.per...@vates.tech>; Andrew Cooper <andrew.coop...@citrix.com>;
> Orzel, Michal <michal.or...@amd.com>; Julien Grall <jul...@xen.org>; Roger Pau
> Monné <roger....@citrix.com>; Stefano Stabellini <sstabell...@kernel.org>;
> xen-
> de...@lists.xenproject.org
> Subject: Re: [PATCH v7 13/13] xen/cpufreq: Adapt SET/GET_CPUFREQ_CPPC
> xen_sysctl_pm_op for amd-cppc driver
>
> On 28.08.2025 08:35, Jan Beulich wrote:
> > On 28.08.2025 06:06, Penny, Zheng wrote:
> >>> -----Original Message-----
> >>> From: Jan Beulich <jbeul...@suse.com>
> >>> Sent: Tuesday, August 26, 2025 12:03 AM
> >>>
> >>> On 22.08.2025 12:52, Penny Zheng wrote:
> >>>> --- a/xen/include/public/sysctl.h
> >>>> +++ b/xen/include/public/sysctl.h
> >>>> @@ -336,8 +336,14 @@ struct xen_ondemand {
> >>>> uint32_t up_threshold;
> >>>> };
> >>>>
> >>>> +#define CPUFREQ_POLICY_UNKNOWN 0
> >>>> +#define CPUFREQ_POLICY_POWERSAVE 1
> >>>> +#define CPUFREQ_POLICY_PERFORMANCE 2
> >>>> +#define CPUFREQ_POLICY_ONDEMAND 3
> >>>
> >>> Without XEN_ prefixes they shouldn't appear in a public header. But
> >>> do we need ...
> >>>
> >>>> struct xen_get_cppc_para {
> >>>> /* OUT */
> >>>> + uint32_t policy; /* CPUFREQ_POLICY_xxx */
> >>>
> >>> ... the new field at all? Can't you synthesize the kind-of-governor
> >>> into struct xen_get_cpufreq_para's respective field? You invoke both
> >>> sub-ops from xenpm now anyway ...
> >>>
> >>
> >> Maybe I could borrow governor field to indicate policy info, like the
> >> following in
> print_cpufreq_para(), then we don't need to add the new filed "policy"
> >> ```
> >> + /* Translate governor info to policy info in CPPC active mode */
> >> + if ( is_cppc_active )
> >> + {
> >> + if ( !strncmp(p_cpufreq->u.s.scaling_governor,
> >> + "ondemand", CPUFREQ_NAME_LEN) )
> >> + printf("cppc policy : ondemand\n");
> >> + else if ( !strncmp(p_cpufreq->u.s.scaling_governor,
> >> + "performance", CPUFREQ_NAME_LEN) )
> >> + printf("cppc policy : performance\n");
> >> +
> >> + else if ( !strncmp(p_cpufreq->u.s.scaling_governor,
> >> + "powersave", CPUFREQ_NAME_LEN) )
> >> + printf("cppc policy : powersave\n");
> >> + else
> >> + printf("cppc policy : unknown\n");
> >> + }
> >> +
> >> ```
> >
> > Something like this is what I was thinking of, yes.
>
> Albeit - why the complicated if/else sequence? Why not simply print the field
> the
> hypercall returned?
>
userspace governor doesn't have according policy. I could simplify it to
```
if ( !strncmp(p_cpufreq->u.s.scaling_governor,
"userspace", CPUFREQ_NAME_LEN) )
printf("policy : unknown\n");
else
printf("policy : %s\n",
p_cpufreq->u.s.scaling_governor);
```
> Jan
