Re: [PATCH v1 06/19] xen/sysctl: wrap around XEN_SYSCTL_perfc_op

[Stefano Stabellini <sstabellini@xxxxxxxxxx>]

On Thu, 13 Mar 2025, Jan Beulich wrote:
> On 13.03.2025 00:12, Stefano Stabellini wrote:
> > On Wed, 12 Mar 2025, Penny Zheng wrote:
> >> perfc_control() and perfc_copy_info() are responsible for providing control
> >> of perf counters via XEN_SYSCTL_perfc_op in DOM0, so they both shall
> >> be wrapped.
> >>
> >> Signed-off-by: Penny Zheng <Penny.Zheng@xxxxxxx>
> >> ---
> >>  xen/common/perfc.c      | 2 ++
> >>  xen/include/xen/perfc.h | 8 ++++++++
> >>  2 files changed, 10 insertions(+)
> >>
> >> diff --git a/xen/common/perfc.c b/xen/common/perfc.c
> >> index 8302b7cf6d..0f3b89af2c 100644
> >> --- a/xen/common/perfc.c
> >> +++ b/xen/common/perfc.c
> >> @@ -149,6 +149,7 @@ void cf_check perfc_reset(unsigned char key)
> >>      }
> >>  }
> >>  
> >> +#ifdef CONFIG_SYSCTL
> > 
> > I think in this case it would be best to make CONFIG_PERF_COUNTERS
> > depending on CONFIG_SYSCTL. The consequence is that without
> > CONFIG_SYSCTL, xen/common/perfc.c will be disabled in the build.
> 
> But perf counters can be used without sysctl, via the dedicated debug
> keys.

I checked the code, and you are right, please ignore my comment here,
and also the similar comment to the next patch