Re: REGRESSION on linux-next (next-20250919)

["Borah, Chaitanya Kumar" <chaitanya.kumar.borah@intel.com>]

Hi,

On 10/6/2025 1:33 PM, Borah, Chaitanya Kumar wrote:
> Thank you for your responses.
> 
> Following change fixes the issue for us.
> 
> 
> diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c
> index 40ac4cb44ed2..487ad19a236e 100644
> --- a/arch/x86/kvm/pmu.c
> +++ b/arch/x86/kvm/pmu.c
> @@ -108,16 +108,18 @@ void kvm_init_pmu_capability(const struct 
> kvm_pmu_ops *pmu_ops)
>          bool is_intel = boot_cpu_data.x86_vendor == X86_VENDOR_INTEL;
>          int min_nr_gp_ctrs = pmu_ops->MIN_NR_GP_COUNTERS;
> 
> -       perf_get_x86_pmu_capability(&kvm_host_pmu);
> -
>          /*
>           * Hybrid PMUs don't play nice with virtualization without careful
>           * configuration by userspace, and KVM's APIs for reporting 
> supported
>           * vPMU features do not account for hybrid PMUs.  Disable vPMU 
> support
>           * for hybrid PMUs until KVM gains a way to let userspace opt-in.
>           */
> -       if (cpu_feature_enabled(X86_FEATURE_HYBRID_CPU))
> +       if (cpu_feature_enabled(X86_FEATURE_HYBRID_CPU)) {
>                  enable_pmu = false;
> +               memset(&kvm_host_pmu, 0, sizeof(kvm_host_pmu));
> +       } else {
> +               perf_get_x86_pmu_capability(&kvm_host_pmu);
> +       }

Can we expect a formal patch soon?

Regards

Chaitanya