[Patch v3 14/22] perf/x86/intel: Add counter group support for arch-PEBS

Dapeng Mi
2025-04-15T08:24:00Z

Base on previous adaptive PEBS counter snapshot support, add counter
group support for architectural PEBS. Since arch-PEBS shares same
counter group layout with adaptive PEBS, directly reuse
__setup_pebs_counter_group() helper to process arch-PEBS counter group.

Signed-off-by: Dapeng Mi <dapeng1.mi@linux.intel.com>
---
arch/x86/events/intel/core.c | 38 ++++++++++++++++++++++++++++---
arch/x86/events/intel/ds.c | 29 ++++++++++++++++++++---
arch/x86/include/asm/msr-index.h | 6 +++++
arch/x86/include/asm/perf_event.h | 13 ++++++++---
4 files changed, 77 insertions(+), 9 deletions(-)

diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c
index ae7f5dfee041..d543ed052743 100644
--- a/arch/x86/events/intel/core.c
+++ b/arch/x86/events/intel/core.c
@@ -3009,6 +3009,17 @@ static void intel_pmu_enable_event_ext(struct perf_event *event)

if (pebs_data_cfg & PEBS_DATACFG_LBRS)
ext |= ARCH_PEBS_LBR & cap.caps;
+
+ if (pebs_data_cfg &
+ (PEBS_DATACFG_CNTR_MASK << PEBS_DATACFG_CNTR_SHIFT))
+ ext |= ARCH_PEBS_CNTR_GP & cap.caps;
+
+ if (pebs_data_cfg &
+ (PEBS_DATACFG_FIX_MASK << PEBS_DATACFG_FIX_SHIFT))
+ ext |= ARCH_PEBS_CNTR_FIXED & cap.caps;
+
+ if (pebs_data_cfg & PEBS_DATACFG_METRICS)
+ ext |= ARCH_PEBS_CNTR_METRICS & cap.caps;
}

if (cpuc->n_pebs == cpuc->n_large_pebs)
@@ -3034,6 +3045,9 @@ static void intel_pmu_enable_event_ext(struct perf_event *event)
}
}

+ if (is_pebs_counter_event_group(event))
+ ext |= ARCH_PEBS_CNTR_ALLOW;
+
if (cpuc->cfg_c_val[hwc->idx] != ext)
__intel_pmu_update_event_ext(hwc->idx, ext);
}
@@ -4318,6 +4332,20 @@ static bool intel_pmu_is_acr_group(struct perf_event *event)
return false;
}

+static inline bool intel_pmu_has_pebs_counter_group(struct pmu *pmu)
+{
+ u64 caps;
+
+ if (x86_pmu.intel_cap.pebs_format >= 6 && x86_pmu.intel_cap.pebs_baseline)
+ return true;
+
+ caps = hybrid(pmu, arch_pebs_cap).caps;
+ if (x86_pmu.arch_pebs && (caps & ARCH_PEBS_CNTR_MASK))
+ return true;
+
+ return false;
+}
+
static inline void intel_pmu_set_acr_cntr_constr(struct perf_event *event,
u64 *cause_mask, int *num)
{
@@ -4464,8 +4492,7 @@ static int intel_pmu_hw_config(struct perf_event *event)
}

if ((event->attr.sample_type & PERF_SAMPLE_READ) &&
- (x86_pmu.intel_cap.pebs_format >= 6) &&
- x86_pmu.intel_cap.pebs_baseline &&
+ intel_pmu_has_pebs_counter_group(event->pmu) &&
is_sampling_event(event) &&
event->attr.precise_ip)
event->group_leader->hw.flags |= PERF_X86_EVENT_PEBS_CNTR;
@@ -5407,6 +5434,8 @@ static inline void __intel_update_large_pebs_flags(struct pmu *pmu)
x86_pmu.large_pebs_flags |= PERF_SAMPLE_TIME;
if (caps & ARCH_PEBS_LBR)
x86_pmu.large_pebs_flags |= PERF_SAMPLE_BRANCH_STACK;
+ if (caps & ARCH_PEBS_CNTR_MASK)
+ x86_pmu.large_pebs_flags |= PERF_SAMPLE_READ;

if (!(caps & ARCH_PEBS_AUX))
x86_pmu.large_pebs_flags &= ~PERF_SAMPLE_DATA_SRC;
@@ -7108,8 +7137,11 @@ __init int intel_pmu_init(void)
* Many features on and after V6 require dynamic constraint,
* e.g., Arch PEBS, ACR.
*/
- if (version >= 6)
+ if (version >= 6) {
x86_pmu.flags |= PMU_FL_DYN_CONSTRAINT;
+ x86_pmu.late_setup = intel_pmu_late_setup;
+ }
+
/*
* Install the hw-cache-events table:
*/
diff --git a/arch/x86/events/intel/ds.c b/arch/x86/events/intel/ds.c
index 6a138435092d..19b51b4d0d94 100644
--- a/arch/x86/events/intel/ds.c
+++ b/arch/x86/events/intel/ds.c
@@ -1514,13 +1514,20 @@ pebs_update_state(bool needed_cb, struct cpu_hw_events *cpuc,

u64 intel_get_arch_pebs_data_config(struct perf_event *event)
{
+ struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
u64 pebs_data_cfg = 0;
+ u64 cntr_mask;

if (WARN_ON(event->hw.idx < 0 || event->hw.idx >= X86_PMC_IDX_MAX))
return 0;

pebs_data_cfg |= pebs_update_adaptive_cfg(event);

+ cntr_mask = (PEBS_DATACFG_CNTR_MASK << PEBS_DATACFG_CNTR_SHIFT) |
+ (PEBS_DATACFG_FIX_MASK << PEBS_DATACFG_FIX_SHIFT) |
+ PEBS_DATACFG_CNTR | PEBS_DATACFG_METRICS;
+ pebs_data_cfg |= cpuc->pebs_data_cfg & cntr_mask;
+
return pebs_data_cfg;
}

@@ -2428,6 +2435,24 @@ static void setup_arch_pebs_sample_data(struct perf_event *event,
}
}

+ if (header->cntr) {
+ struct arch_pebs_cntr_header *cntr = next_record;
+ unsigned int nr;
+
+ next_record += sizeof(struct arch_pebs_cntr_header);
+
+ if (is_pebs_counter_event_group(event)) {
+ __setup_pebs_counter_group(cpuc, event,
+ (struct pebs_cntr_header *)cntr, next_record);
+ data->sample_flags |= PERF_SAMPLE_READ;
+ }
+
+ nr = hweight32(cntr->cntr) + hweight32(cntr->fixed);
+ if (cntr->metrics == INTEL_CNTR_METRICS)
+ nr += 2;
+ next_record += nr * sizeof(u64);
+ }
+
/* Parse followed fragments if there are. */
if (arch_pebs_record_continued(header)) {
at = at + header->size;
@@ -3057,10 +3082,8 @@ static void __init intel_ds_pebs_init(void)
break;

case 6:
- if (x86_pmu.intel_cap.pebs_baseline) {
+ if (x86_pmu.intel_cap.pebs_baseline)
x86_pmu.large_pebs_flags |= PERF_SAMPLE_READ;
- x86_pmu.late_setup = intel_pmu_late_setup;
- }
fallthrough;
case 5:
x86_pmu.pebs_ept = 1;
diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h
index ea4f100dbd3c..c971ac09d881 100644
--- a/arch/x86/include/asm/msr-index.h
+++ b/arch/x86/include/asm/msr-index.h
@@ -321,12 +321,18 @@
#define ARCH_PEBS_INDEX_WR_SHIFT 4

#define ARCH_PEBS_RELOAD 0xffffffff
+#define ARCH_PEBS_CNTR_ALLOW BIT_ULL(35)
+#define ARCH_PEBS_CNTR_GP BIT_ULL(36)
+#define ARCH_PEBS_CNTR_FIXED BIT_ULL(37)
+#define ARCH_PEBS_CNTR_METRICS BIT_ULL(38)
#define ARCH_PEBS_LBR_SHIFT 40
#define ARCH_PEBS_LBR (0x3ull << ARCH_PEBS_LBR_SHIFT)
#define ARCH_PEBS_VECR_XMM BIT_ULL(49)
#define ARCH_PEBS_GPR BIT_ULL(61)
#define ARCH_PEBS_AUX BIT_ULL(62)
#define ARCH_PEBS_EN BIT_ULL(63)
+#define ARCH_PEBS_CNTR_MASK (ARCH_PEBS_CNTR_GP | ARCH_PEBS_CNTR_FIXED | \
+ ARCH_PEBS_CNTR_METRICS)

#define MSR_IA32_RTIT_CTL 0x00000570
#define RTIT_CTL_TRACEEN BIT(0)
diff --git a/arch/x86/include/asm/perf_event.h b/arch/x86/include/asm/perf_event.h
index 7f9d8e6577f0..4e5adbc7baea 100644
--- a/arch/x86/include/asm/perf_event.h
+++ b/arch/x86/include/asm/perf_event.h
@@ -137,16 +137,16 @@
#define ARCH_PERFMON_EVENTS_COUNT 7

#define PEBS_DATACFG_MEMINFO BIT_ULL(0)
-#define PEBS_DATACFG_GP BIT_ULL(1)
+#define PEBS_DATACFG_GP BIT_ULL(1)
#define PEBS_DATACFG_XMMS BIT_ULL(2)
#define PEBS_DATACFG_LBRS BIT_ULL(3)
-#define PEBS_DATACFG_LBR_SHIFT 24
#define PEBS_DATACFG_CNTR BIT_ULL(4)
+#define PEBS_DATACFG_METRICS BIT_ULL(5)
+#define PEBS_DATACFG_LBR_SHIFT 24
#define PEBS_DATACFG_CNTR_SHIFT 32
#define PEBS_DATACFG_CNTR_MASK GENMASK_ULL(15, 0)
#define PEBS_DATACFG_FIX_SHIFT 48
#define PEBS_DATACFG_FIX_MASK GENMASK_ULL(7, 0)
-#define PEBS_DATACFG_METRICS BIT_ULL(5)

/* Steal the highest bit of pebs_data_cfg for SW usage */
#define PEBS_UPDATE_DS_SW BIT_ULL(63)
@@ -603,6 +603,13 @@ struct arch_pebs_lbr_header {
u64 ler_info;
};

+struct arch_pebs_cntr_header {
+ u32 cntr;
+ u32 fixed;
+ u32 metrics;
+ u32 reserved;
+};
+
/*
* AMD Extended Performance Monitoring and Debug cpuid feature detection
*/
--
2.40.1