Re: [kvm-unit-tests Patch 4/5] x86: pmu: Support validation for Intel PMU fixed counter 3

Mi, Dapeng
2023-10-25T11:26:54Z

On 10/25/2023 3:05 AM, Jim Mattson wrote:
> On Tue, Oct 24, 2023 at 12:51 AM Dapeng Mi <dapeng1.mi@linux.intel.com> wrote:
>> Intel CPUs, like Sapphire Rapids, introduces a new fixed counter
>> (fixed counter 3) to counter/sample topdown.slots event, but current
>> code still doesn't cover this new fixed counter.
>>
>> So add code to validate this new fixed counter.
> Can you explain how this "validates" anything?

I may not describe the sentence clearly. This would validate the fixed
counter 3 can count the slots event and get a valid count in a
reasonable range. Thanks.

>
>> Signed-off-by: Dapeng Mi <dapeng1.mi@linux.intel.com>
>> ---
>> x86/pmu.c | 3 ++-
>> 1 file changed, 2 insertions(+), 1 deletion(-)
>>
>> diff --git a/x86/pmu.c b/x86/pmu.c
>> index 1bebf493d4a4..41165e168d8e 100644
>> --- a/x86/pmu.c
>> +++ b/x86/pmu.c
>> @@ -46,7 +46,8 @@ struct pmu_event {
>> }, fixed_events[] = {
>> {"fixed 1", MSR_CORE_PERF_FIXED_CTR0, 10*N, 10.2*N},
>> {"fixed 2", MSR_CORE_PERF_FIXED_CTR0 + 1, 1*N, 30*N},
>> - {"fixed 3", MSR_CORE_PERF_FIXED_CTR0 + 2, 0.1*N, 30*N}
>> + {"fixed 3", MSR_CORE_PERF_FIXED_CTR0 + 2, 0.1*N, 30*N},
>> + {"fixed 4", MSR_CORE_PERF_FIXED_CTR0 + 3, 1*N, 100*N}
>> };
>>
>> char *buf;
>> --
>> 2.34.1
>>