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

From: Jim Mattson
Date: Tue Oct 24 2023 - 15:05:28 EST


On Tue, Oct 24, 2023 at 12:51 AM Dapeng Mi <dapeng1.mi@xxxxxxxxxxxxxxx> 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?

> Signed-off-by: Dapeng Mi <dapeng1.mi@xxxxxxxxxxxxxxx>
> ---
> 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
>