Re: [PATCH 1/3] perf/x86: Add PERF_CAP_PEBS_TIMING_INFO flag

[Mi, Dapeng]

Run basic perf  counting, PMI based sampling and PEBS based sampling on
Intel Sapphire Rapids, Granite Rapids and Sierra Forest platforms, no issue
is found.

On 7/17/2025 5:03 PM, Dapeng Mi wrote:
> IA32_PERF_CAPABILITIES.PEBS_TIMING_INFO[bit 17] is introduced to
> indicate whether timed PEBS is supported. Timed PEBS adds a new "retired
> latency" field in basic info group to show the timing info. Please find
> detailed information about timed PEBS in section 8.4.1 "Timed Processor
> Event Based Sampling" of "Intel Architecture Instruction Set Extensions
> and Future Features".
>
> This patch adds PERF_CAP_PEBS_TIMING_INFO flag and KVM module leverages
> this flag to expose timed PEBS feature to guest.
>
> Moreover, opportunistically refine the indents and make the macros
> share consistent indents.
>
> Signed-off-by: Dapeng Mi <dapeng1.mi@xxxxxxxxxxxxxxx>
> Tested-by: Yi Lai <yi1.lai@xxxxxxxxx>
> ---
>  arch/x86/include/asm/msr-index.h       | 14 ++++++++------
>  tools/arch/x86/include/asm/msr-index.h | 14 ++++++++------
>  2 files changed, 16 insertions(+), 12 deletions(-)
>
> diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h
> index b7dded3c8113..48b7ed28718c 100644
> --- a/arch/x86/include/asm/msr-index.h
> +++ b/arch/x86/include/asm/msr-index.h
> @@ -315,12 +315,14 @@
>  #define PERF_CAP_PT_IDX			16
>  
>  #define MSR_PEBS_LD_LAT_THRESHOLD	0x000003f6
> -#define PERF_CAP_PEBS_TRAP             BIT_ULL(6)
> -#define PERF_CAP_ARCH_REG              BIT_ULL(7)
> -#define PERF_CAP_PEBS_FORMAT           0xf00
> -#define PERF_CAP_PEBS_BASELINE         BIT_ULL(14)
> -#define PERF_CAP_PEBS_MASK	(PERF_CAP_PEBS_TRAP | PERF_CAP_ARCH_REG | \
> -				 PERF_CAP_PEBS_FORMAT | PERF_CAP_PEBS_BASELINE)
> +#define PERF_CAP_PEBS_TRAP		BIT_ULL(6)
> +#define PERF_CAP_ARCH_REG		BIT_ULL(7)
> +#define PERF_CAP_PEBS_FORMAT		0xf00
> +#define PERF_CAP_PEBS_BASELINE		BIT_ULL(14)
> +#define PERF_CAP_PEBS_TIMING_INFO	BIT_ULL(17)
> +#define PERF_CAP_PEBS_MASK		(PERF_CAP_PEBS_TRAP | PERF_CAP_ARCH_REG | \
> +					 PERF_CAP_PEBS_FORMAT | PERF_CAP_PEBS_BASELINE | \
> +					 PERF_CAP_PEBS_TIMING_INFO)
>  
>  #define MSR_IA32_RTIT_CTL		0x00000570
>  #define RTIT_CTL_TRACEEN		BIT(0)
> diff --git a/tools/arch/x86/include/asm/msr-index.h b/tools/arch/x86/include/asm/msr-index.h
> index b7dded3c8113..48b7ed28718c 100644
> --- a/tools/arch/x86/include/asm/msr-index.h
> +++ b/tools/arch/x86/include/asm/msr-index.h
> @@ -315,12 +315,14 @@
>  #define PERF_CAP_PT_IDX			16
>  
>  #define MSR_PEBS_LD_LAT_THRESHOLD	0x000003f6
> -#define PERF_CAP_PEBS_TRAP             BIT_ULL(6)
> -#define PERF_CAP_ARCH_REG              BIT_ULL(7)
> -#define PERF_CAP_PEBS_FORMAT           0xf00
> -#define PERF_CAP_PEBS_BASELINE         BIT_ULL(14)
> -#define PERF_CAP_PEBS_MASK	(PERF_CAP_PEBS_TRAP | PERF_CAP_ARCH_REG | \
> -				 PERF_CAP_PEBS_FORMAT | PERF_CAP_PEBS_BASELINE)
> +#define PERF_CAP_PEBS_TRAP		BIT_ULL(6)
> +#define PERF_CAP_ARCH_REG		BIT_ULL(7)
> +#define PERF_CAP_PEBS_FORMAT		0xf00
> +#define PERF_CAP_PEBS_BASELINE		BIT_ULL(14)
> +#define PERF_CAP_PEBS_TIMING_INFO	BIT_ULL(17)
> +#define PERF_CAP_PEBS_MASK		(PERF_CAP_PEBS_TRAP | PERF_CAP_ARCH_REG | \
> +					 PERF_CAP_PEBS_FORMAT | PERF_CAP_PEBS_BASELINE | \
> +					 PERF_CAP_PEBS_TIMING_INFO)
>  
>  #define MSR_IA32_RTIT_CTL		0x00000570
>  #define RTIT_CTL_TRACEEN		BIT(0)
>
> base-commit: 829f5a6308ce11c3edaa31498a825f8c41b9e9aa