Re: [PATCH v3 14/15] xen/xenpm: Adapt cpu frequency monitor in xenpm

["Anthony PERARD" <anthony.perard@xxxxxxxxxx>]

On Tue, Mar 25, 2025 at 12:26:09PM +0100, Jan Beulich wrote:
> On 06.03.2025 09:39, Penny Zheng wrote:
> > Make `xenpm get-cpureq-para/set-cpufreq-para` available in CPPC mode.
> > --- a/tools/libs/ctrl/xc_pm.c
> > +++ b/tools/libs/ctrl/xc_pm.c
> > @@ -214,13 +214,12 @@ int xc_get_cpufreq_para(xc_interface *xch, int cpuid,
> > @@ -301,7 +302,8 @@ unlock_4:
> >      if ( user_para->gov_num )
> >          xc_hypercall_bounce_post(xch, scaling_available_governors);
> >  unlock_3:
> > -    xc_hypercall_bounce_post(xch, scaling_available_frequencies);
> > +    if ( user_para->freq_num )
> > +        xc_hypercall_bounce_post(xch, scaling_available_frequencies);
> >  unlock_2:
> >      xc_hypercall_bounce_post(xch, affected_cpus);
> >  unlock_1:
> 
> I'm also puzzled by the function's inconsistent return value - Anthony,
> can you explain / spot why things are the way they are?

Looks like 73367cf3b4b4 ("libxc: Fix xc_pm API calls to return negative
error and stash error in errno.") made some changes, and fixed some
return value to be like described in "xenctrl.h", but I guess failed to
also change the "ret = -errno".

Cheers,

-- 

Anthony Perard | Vates XCP-ng Developer

XCP-ng & Xen Orchestra - Vates solutions

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