Re: [PATCH v3] powerpc/pseries/Kconfig: Enable CONFIG_VPA_PMU to be used with KVM

[Harsh Prateek Bora <harshpb@linux.ibm.com>]

On 29/05/26 7:40 pm, Gautam Menghani wrote:
> Currently, CONFIG_VPA_PMU is not enabled any of the configs, and

Not sure what is meant by "any of the configs" , distros ?
We could just say "not enabled by default" ..

> consequently cannot be used for KVM guests at all.

.. consequently cannot be used for KVM guests unless explicitly enabled 
on host kernel (which is currently ignored by distro configs)?

> 
> Mark CONFIG_VPA_PMU as "default m" to ensure it is available when KVM is
> being used.

I think title could have been rephrased to focus on "default m" enablement.

> 
> Fixes: 176cda0619b6c ("powerpc/perf: Add perf interface to expose vpa counters")
> Cc: stable@vger.kernel.org # v6.13+
> Suggested-by: Sean Christopherson <seanjc@google.com>
> Signed-off-by: Gautam Menghani <gautam@linux.ibm.com>
> ---
> v2 -> v3:
> 1. Make CONFIG_VPA_PMU as default m so that it can separately disabled
> (Sean)


This indeed is more appropriate way for enablement, thanks Sean!

regards,
Harsh

> 
> v1 -> v2:
> 1. Rebased on latest master
> 
>   arch/powerpc/platforms/pseries/Kconfig | 1 +
>   1 file changed, 1 insertion(+)
> 
> diff --git a/arch/powerpc/platforms/pseries/Kconfig b/arch/powerpc/platforms/pseries/Kconfig
> index f7052b131a4c..74910ce3a541 100644
> --- a/arch/powerpc/platforms/pseries/Kconfig
> +++ b/arch/powerpc/platforms/pseries/Kconfig
> @@ -154,6 +154,7 @@ config HV_PERF_CTRS
>   config VPA_PMU
>   	tristate "VPA PMU events"
>   	depends on KVM_BOOK3S_64_HV && HV_PERF_CTRS
> +	default m
>   	help
>   	  Enable access to the VPA PMU counters via perf. This enables
>   	  code that support measurement for KVM on PowerVM(KoP) feature.