[Patch v7 07/24] perf/x86: Introduce x86-specific x86_pmu_setup_regs_data()

Dapeng Mi
2026-03-24T00:46:24Z

From: Kan Liang <kan.liang@linux.intel.com>

The current perf/x86 implementation uses the generic functions
perf_sample_regs_user() and perf_sample_regs_intr() to set up registers
data for sampling records. While this approach works for general
registers, it falls short when adding sampling support for SIMD and APX
eGPRs registers on x86 platforms.

To address this, we introduce the x86-specific function
x86_pmu_setup_regs_data() for setting up register data on x86 platforms.

At present, x86_pmu_setup_regs_data() mirrors the logic of the generic
functions perf_sample_regs_user() and perf_sample_regs_intr().
Subsequent patches will introduce x86-specific enhancements.

Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Dapeng Mi <dapeng1.mi@linux.intel.com>
---
arch/x86/events/core.c | 33 +++++++++++++++++++++++++++++++++
arch/x86/events/intel/ds.c | 9 ++++++---
arch/x86/events/perf_event.h | 4 ++++
3 files changed, 43 insertions(+), 3 deletions(-)

diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c
index ad6cbc19592d..0a6c51e86e9b 100644
--- a/arch/x86/events/core.c
+++ b/arch/x86/events/core.c
@@ -1699,6 +1699,39 @@ static void x86_pmu_del(struct perf_event *event, int flags)
static_call_cond(x86_pmu_del)(event);
}

+void x86_pmu_setup_regs_data(struct perf_event *event,
+ struct perf_sample_data *data,
+ struct pt_regs *regs)
+{
+ struct perf_event_attr *attr = &event->attr;
+ u64 sample_type = attr->sample_type;
+
+ if (sample_type & PERF_SAMPLE_REGS_USER) {
+ if (user_mode(regs)) {
+ data->regs_user.abi = perf_reg_abi(current);
+ data->regs_user.regs = regs;
+ } else if (!(current->flags & PF_KTHREAD)) {
+ perf_get_regs_user(&data->regs_user, regs);
+ } else {
+ data->regs_user.abi = PERF_SAMPLE_REGS_ABI_NONE;
+ data->regs_user.regs = NULL;
+ }
+ data->dyn_size += sizeof(u64);
+ if (data->regs_user.regs)
+ data->dyn_size += hweight64(attr->sample_regs_user) * sizeof(u64);
+ data->sample_flags |= PERF_SAMPLE_REGS_USER;
+ }
+
+ if (sample_type & PERF_SAMPLE_REGS_INTR) {
+ data->regs_intr.regs = regs;
+ data->regs_intr.abi = perf_reg_abi(current);
+ data->dyn_size += sizeof(u64);
+ if (data->regs_intr.regs)
+ data->dyn_size += hweight64(attr->sample_regs_intr) * sizeof(u64);
+ data->sample_flags |= PERF_SAMPLE_REGS_INTR;
+ }
+}
+
int x86_pmu_handle_irq(struct pt_regs *regs)
{
struct perf_sample_data data;
diff --git a/arch/x86/events/intel/ds.c b/arch/x86/events/intel/ds.c
index 52eb6eac5df3..b045297c02d0 100644
--- a/arch/x86/events/intel/ds.c
+++ b/arch/x86/events/intel/ds.c
@@ -2450,6 +2450,7 @@ static inline void __setup_pebs_basic_group(struct perf_event *event,
}

static inline void __setup_pebs_gpr_group(struct perf_event *event,
+ struct perf_sample_data *data,
struct pt_regs *regs,
struct pebs_gprs *gprs,
u64 sample_type)
@@ -2459,8 +2460,10 @@ static inline void __setup_pebs_gpr_group(struct perf_event *event,
regs->flags &= ~PERF_EFLAGS_EXACT;
}

- if (sample_type & (PERF_SAMPLE_REGS_INTR | PERF_SAMPLE_REGS_USER))
+ if (sample_type & (PERF_SAMPLE_REGS_INTR | PERF_SAMPLE_REGS_USER)) {
adaptive_pebs_save_regs(regs, gprs);
+ x86_pmu_setup_regs_data(event, data, regs);
+ }
}

static inline void __setup_pebs_meminfo_group(struct perf_event *event,
@@ -2553,7 +2556,7 @@ static void setup_pebs_adaptive_sample_data(struct perf_event *event,
gprs = next_record;
next_record = gprs + 1;

- __setup_pebs_gpr_group(event, regs, gprs, sample_type);
+ __setup_pebs_gpr_group(event, data, regs, gprs, sample_type);
}

if (format_group & PEBS_DATACFG_MEMINFO) {
@@ -2677,7 +2680,7 @@ static void setup_arch_pebs_sample_data(struct perf_event *event,
gprs = next_record;
next_record = gprs + 1;

- __setup_pebs_gpr_group(event, regs,
+ __setup_pebs_gpr_group(event, data, regs,
(struct pebs_gprs *)gprs,
sample_type);
}
diff --git a/arch/x86/events/perf_event.h b/arch/x86/events/perf_event.h
index fad87d3c8b2c..39c41947c70d 100644
--- a/arch/x86/events/perf_event.h
+++ b/arch/x86/events/perf_event.h
@@ -1306,6 +1306,10 @@ void x86_pmu_enable_event(struct perf_event *event);

int x86_pmu_handle_irq(struct pt_regs *regs);

+void x86_pmu_setup_regs_data(struct perf_event *event,
+ struct perf_sample_data *data,
+ struct pt_regs *regs);
+
void x86_pmu_show_pmu_cap(struct pmu *pmu);

static inline int x86_pmu_num_counters(struct pmu *pmu)
--
2.34.1