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

["Mi, Dapeng" <dapeng1.mi@linux.intel.com>]

On 10/7/2025 2:22 PM, Borah, Chaitanya Kumar wrote:
> 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?

I'd like to post a patch to fix this tomorrow if Sean has no bandwidth on
this. Thanks.


>
> Regards
>
> Chaitanya