Re: [PATCH v2 2/5] KVM: selftests: Add timing_info bit support in vmx_pmu_caps_test

Sean Christopherson
2025-09-10T22:03:54Z

On Fri, Jul 18, 2025, Dapeng Mi wrote:
> A new bit PERF_CAPABILITIES[17] called "PEBS_TIMING_INFO" bit is added
> to indicated if PEBS supports to record timing information in a new
> "Retried Latency" field.
>
> Since KVM requires user can only set host consistent PEBS capabilities,
> otherwise the PERF_CAPABILITIES setting would fail, so add
> pebs_timing_info bit into "immutable_caps" to block host inconsistent
> PEBS configuration and cause errors.

Please explain the removal of anythread_deprecated. AFAICT, something like this
is accurate:

Opportunistically drop the anythread_deprecated bit. It isn't and likely
never was a PERF_CAPABILITIES flag, the test's definition snuck in when
the union was copy+pasted from the kernel's definition.

> Signed-off-by: Dapeng Mi <dapeng1.mi@linux.intel.com>
> Tested-by: Yi Lai <yi1.lai@intel.com>
> ---
> tools/testing/selftests/kvm/x86/vmx_pmu_caps_test.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/tools/testing/selftests/kvm/x86/vmx_pmu_caps_test.c b/tools/testing/selftests/kvm/x86/vmx_pmu_caps_test.c
> index a1f5ff45d518..f8deea220156 100644
> --- a/tools/testing/selftests/kvm/x86/vmx_pmu_caps_test.c
> +++ b/tools/testing/selftests/kvm/x86/vmx_pmu_caps_test.c
> @@ -29,7 +29,7 @@ static union perf_capabilities {
> u64 pebs_baseline:1;
> u64 perf_metrics:1;
> u64 pebs_output_pt_available:1;
> - u64 anythread_deprecated:1;
> + u64 pebs_timing_info:1;
> };
> u64 capabilities;
> } host_cap;
> @@ -44,6 +44,7 @@ static const union perf_capabilities immutable_caps = {
> .pebs_arch_reg = 1,
> .pebs_format = -1,
> .pebs_baseline = 1,
> + .pebs_timing_info = 1,
> };
>
> static const union perf_capabilities format_caps = {
> --
> 2.34.1
>