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Message-ID: <CAP-5=fVBsrF0_JiyXTF7QjsqAEox_d8exGjhrsDLsipw=yE_eQ@mail.gmail.com>
Date: Wed, 3 Dec 2025 23:28:55 -0800
From: Ian Rogers <irogers@...gle.com>
To: "Mi, Dapeng" <dapeng1.mi@...ux.intel.com>
Cc: Peter Zijlstra <peterz@...radead.org>, Ingo Molnar <mingo@...hat.com>,
Arnaldo Carvalho de Melo <acme@...nel.org>, Namhyung Kim <namhyung@...nel.org>,
Thomas Gleixner <tglx@...utronix.de>, Dave Hansen <dave.hansen@...ux.intel.com>,
Adrian Hunter <adrian.hunter@...el.com>, Jiri Olsa <jolsa@...nel.org>,
Alexander Shishkin <alexander.shishkin@...ux.intel.com>, Andi Kleen <ak@...ux.intel.com>,
Eranian Stephane <eranian@...gle.com>, Mark Rutland <mark.rutland@....com>, broonie@...nel.org,
Ravi Bangoria <ravi.bangoria@....com>, linux-kernel@...r.kernel.org,
linux-perf-users@...r.kernel.org, Zide Chen <zide.chen@...el.com>,
Falcon Thomas <thomas.falcon@...el.com>, Dapeng Mi <dapeng1.mi@...el.com>,
Xudong Hao <xudong.hao@...el.com>, Kan Liang <kan.liang@...ux.intel.com>
Subject: Re: [Patch v5 17/19] perf headers: Sync with the kernel headers
On Wed, Dec 3, 2025 at 5:38 PM Mi, Dapeng <dapeng1.mi@...ux.intel.com> wrote:
>
>
> On 12/4/2025 7:43 AM, Ian Rogers wrote:
> > On Tue, Dec 2, 2025 at 10:59 PM Dapeng Mi <dapeng1.mi@...ux.intel.com> wrote:
> >> From: Kan Liang <kan.liang@...ux.intel.com>
> >>
> >> Update include/uapi/linux/perf_event.h and
> >> arch/x86/include/uapi/asm/perf_regs.h to support extended regs.
> >>
> >> Signed-off-by: Kan Liang <kan.liang@...ux.intel.com>
> >> Co-developed-by: Dapeng Mi <dapeng1.mi@...ux.intel.com>
> >> Signed-off-by: Dapeng Mi <dapeng1.mi@...ux.intel.com>
> >> ---
> >> tools/arch/x86/include/uapi/asm/perf_regs.h | 62 +++++++++++++++++++++
> >> tools/include/uapi/linux/perf_event.h | 45 +++++++++++++--
> >> 2 files changed, 103 insertions(+), 4 deletions(-)
> >>
> >> diff --git a/tools/arch/x86/include/uapi/asm/perf_regs.h b/tools/arch/x86/include/uapi/asm/perf_regs.h
> >> index 7c9d2bb3833b..f3561ed10041 100644
> >> --- a/tools/arch/x86/include/uapi/asm/perf_regs.h
> >> +++ b/tools/arch/x86/include/uapi/asm/perf_regs.h
> >> @@ -27,9 +27,34 @@ enum perf_event_x86_regs {
> >> PERF_REG_X86_R13,
> >> PERF_REG_X86_R14,
> >> PERF_REG_X86_R15,
> >> + /*
> >> + * The EGPRs/SSP and XMM have overlaps. Only one can be used
> >> + * at a time. For the ABI type PERF_SAMPLE_REGS_ABI_SIMD,
> >> + * utilize EGPRs/SSP. For the other ABI type, XMM is used.
> >> + *
> >> + * Extended GPRs (EGPRs)
> >> + */
> >> + PERF_REG_X86_R16,
> >> + PERF_REG_X86_R17,
> >> + PERF_REG_X86_R18,
> >> + PERF_REG_X86_R19,
> >> + PERF_REG_X86_R20,
> >> + PERF_REG_X86_R21,
> >> + PERF_REG_X86_R22,
> >> + PERF_REG_X86_R23,
> >> + PERF_REG_X86_R24,
> >> + PERF_REG_X86_R25,
> >> + PERF_REG_X86_R26,
> >> + PERF_REG_X86_R27,
> >> + PERF_REG_X86_R28,
> >> + PERF_REG_X86_R29,
> >> + PERF_REG_X86_R30,
> >> + PERF_REG_X86_R31,
> >> + PERF_REG_X86_SSP,
> >> /* These are the limits for the GPRs. */
> >> PERF_REG_X86_32_MAX = PERF_REG_X86_GS + 1,
> >> PERF_REG_X86_64_MAX = PERF_REG_X86_R15 + 1,
> >> + PERF_REG_MISC_MAX = PERF_REG_X86_SSP + 1,
> > I wonder MISC isn't the most intention revealing name. What happens if
> > things are extended again? Would APX be a better alternative, so
> > PERF_REG_APX_MAX ?
>
> Hmm, I don't think PERF_REG_APX_MAX is a good name either since there is
> SSP as well besides the APX eGPRs, and there could be more registers
> introduced in the future.
>
> How about PERF_REG_X86_EXTD_MAX?
Sounds good to me, especially with the eGPR already using the term extended.
Thanks,
Ian
> >
> >> /* These all need two bits set because they are 128bit */
> >> PERF_REG_X86_XMM0 = 32,
> >> @@ -54,5 +79,42 @@ enum perf_event_x86_regs {
> >> };
> >>
> >> #define PERF_REG_EXTENDED_MASK (~((1ULL << PERF_REG_X86_XMM0) - 1))
> >> +#define PERF_X86_EGPRS_MASK GENMASK_ULL(PERF_REG_X86_R31, PERF_REG_X86_R16)
> >> +
> >> +enum {
> >> + PERF_REG_X86_XMM,
> >> + PERF_REG_X86_YMM,
> >> + PERF_REG_X86_ZMM,
> >> + PERF_REG_X86_MAX_SIMD_REGS,
> >> +
> >> + PERF_REG_X86_OPMASK = 0,
> >> + PERF_REG_X86_MAX_PRED_REGS = 1,
> >> +};
> >> +
> >> +enum {
> >> + PERF_X86_SIMD_XMM_REGS = 16,
> >> + PERF_X86_SIMD_YMM_REGS = 16,
> >> + PERF_X86_SIMD_ZMMH_REGS = 16,
> >> + PERF_X86_SIMD_ZMM_REGS = 32,
> >> + PERF_X86_SIMD_VEC_REGS_MAX = PERF_X86_SIMD_ZMM_REGS,
> >> +
> >> + PERF_X86_SIMD_OPMASK_REGS = 8,
> >> + PERF_X86_SIMD_PRED_REGS_MAX = PERF_X86_SIMD_OPMASK_REGS,
> >> +};
> >> +
> >> +#define PERF_X86_SIMD_PRED_MASK GENMASK(PERF_X86_SIMD_PRED_REGS_MAX - 1, 0)
> >> +#define PERF_X86_SIMD_VEC_MASK GENMASK_ULL(PERF_X86_SIMD_VEC_REGS_MAX - 1, 0)
> >> +
> >> +#define PERF_X86_H16ZMM_BASE PERF_X86_SIMD_ZMMH_REGS
> >> +
> >> +enum {
> >> + PERF_X86_OPMASK_QWORDS = 1,
> >> + PERF_X86_XMM_QWORDS = 2,
> >> + PERF_X86_YMMH_QWORDS = 2,
> >> + PERF_X86_YMM_QWORDS = 4,
> >> + PERF_X86_ZMMH_QWORDS = 4,
> >> + PERF_X86_ZMM_QWORDS = 8,
> >> + PERF_X86_SIMD_QWORDS_MAX = PERF_X86_ZMM_QWORDS,
> >> +};
> >>
> >> #endif /* _ASM_X86_PERF_REGS_H */
> >> diff --git a/tools/include/uapi/linux/perf_event.h b/tools/include/uapi/linux/perf_event.h
> >> index d292f96bc06f..f1474da32622 100644
> >> --- a/tools/include/uapi/linux/perf_event.h
> >> +++ b/tools/include/uapi/linux/perf_event.h
> >> @@ -314,8 +314,9 @@ enum {
> >> */
> >> enum perf_sample_regs_abi {
> >> PERF_SAMPLE_REGS_ABI_NONE = 0,
> >> - PERF_SAMPLE_REGS_ABI_32 = 1,
> >> - PERF_SAMPLE_REGS_ABI_64 = 2,
> >> + PERF_SAMPLE_REGS_ABI_32 = (1 << 0),
> >> + PERF_SAMPLE_REGS_ABI_64 = (1 << 1),
> >> + PERF_SAMPLE_REGS_ABI_SIMD = (1 << 2),
> >> };
> >>
> >> /*
> >> @@ -382,6 +383,7 @@ enum perf_event_read_format {
> >> #define PERF_ATTR_SIZE_VER6 120 /* Add: aux_sample_size */
> >> #define PERF_ATTR_SIZE_VER7 128 /* Add: sig_data */
> >> #define PERF_ATTR_SIZE_VER8 136 /* Add: config3 */
> >> +#define PERF_ATTR_SIZE_VER9 168 /* Add: sample_simd_{pred,vec}_reg_* */
> > ARM have added a config4 in:
> > https://lore.kernel.org/lkml/20251111-james-perf-feat_spe_eft-v10-1-1e1b5bf2cd05@linaro.org/
> > so this will need to be VER10.
>
> Thanks. It looks the ARM changes have been merged, so we can change it to
> VER10 in next version.
>
>
> >
> > Thanks,
> > Ian
> >
> >> /*
> >> * 'struct perf_event_attr' contains various attributes that define
> >> @@ -545,6 +547,25 @@ struct perf_event_attr {
> >> __u64 sig_data;
> >>
> >> __u64 config3; /* extension of config2 */
> >> +
> >> +
> >> + /*
> >> + * Defines set of SIMD registers to dump on samples.
> >> + * The sample_simd_regs_enabled !=0 implies the
> >> + * set of SIMD registers is used to config all SIMD registers.
> >> + * If !sample_simd_regs_enabled, sample_regs_XXX may be used to
> >> + * config some SIMD registers on X86.
> >> + */
> >> + union {
> >> + __u16 sample_simd_regs_enabled;
> >> + __u16 sample_simd_pred_reg_qwords;
> >> + };
> >> + __u32 sample_simd_pred_reg_intr;
> >> + __u32 sample_simd_pred_reg_user;
> >> + __u16 sample_simd_vec_reg_qwords;
> >> + __u64 sample_simd_vec_reg_intr;
> >> + __u64 sample_simd_vec_reg_user;
> >> + __u32 __reserved_4;
> >> };
> >>
> >> /*
> >> @@ -1018,7 +1039,15 @@ enum perf_event_type {
> >> * } && PERF_SAMPLE_BRANCH_STACK
> >> *
> >> * { u64 abi; # enum perf_sample_regs_abi
> >> - * u64 regs[weight(mask)]; } && PERF_SAMPLE_REGS_USER
> >> + * u64 regs[weight(mask)];
> >> + * struct {
> >> + * u16 nr_vectors;
> >> + * u16 vector_qwords;
> >> + * u16 nr_pred;
> >> + * u16 pred_qwords;
> >> + * u64 data[nr_vectors * vector_qwords + nr_pred * pred_qwords];
> >> + * } && (abi & PERF_SAMPLE_REGS_ABI_SIMD)
> >> + * } && PERF_SAMPLE_REGS_USER
> >> *
> >> * { u64 size;
> >> * char data[size];
> >> @@ -1045,7 +1074,15 @@ enum perf_event_type {
> >> * { u64 data_src; } && PERF_SAMPLE_DATA_SRC
> >> * { u64 transaction; } && PERF_SAMPLE_TRANSACTION
> >> * { u64 abi; # enum perf_sample_regs_abi
> >> - * u64 regs[weight(mask)]; } && PERF_SAMPLE_REGS_INTR
> >> + * u64 regs[weight(mask)];
> >> + * struct {
> >> + * u16 nr_vectors;
> >> + * u16 vector_qwords;
> >> + * u16 nr_pred;
> >> + * u16 pred_qwords;
> >> + * u64 data[nr_vectors * vector_qwords + nr_pred * pred_qwords];
> >> + * } && (abi & PERF_SAMPLE_REGS_ABI_SIMD)
> >> + * } && PERF_SAMPLE_REGS_INTR
> >> * { u64 phys_addr;} && PERF_SAMPLE_PHYS_ADDR
> >> * { u64 cgroup;} && PERF_SAMPLE_CGROUP
> >> * { u64 data_page_size;} && PERF_SAMPLE_DATA_PAGE_SIZE
> >> --
> >> 2.34.1
> >>
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