[PATCH v14 17/32] x86,fs/resctrl: Fill in details of events for guid 0x26696143 and 0x26557651

Tony Luck
2025-11-24T18:54:59Z

The telemetry event aggregators of the Intel Clearwater Forest CPU support
two RMID-based feature types: "energy" with guid 0x26696143 [1], and "perf"
with guid 0x26557651 [2].

The event counter offsets in an aggregator's MMIO space are arranged in
groups for each RMID.

E.g the "energy" counters for guid 0x26696143 are arranged like this:

MMIO offset:0x0000 Counter for RMID 0 PMT_EVENT_ENERGY
MMIO offset:0x0008 Counter for RMID 0 PMT_EVENT_ACTIVITY
MMIO offset:0x0010 Counter for RMID 1 PMT_EVENT_ENERGY
MMIO offset:0x0018 Counter for RMID 1 PMT_EVENT_ACTIVITY
...
MMIO offset:0x23F0 Counter for RMID 575 PMT_EVENT_ENERGY
MMIO offset:0x23F8 Counter for RMID 575 PMT_EVENT_ACTIVITY

After all counters there are three status registers that provide
indications of how many times an aggregator was unable to process
event counts, the time stamp for the most recent loss of data, and
the time stamp of the most recent successful update.

MMIO offset:0x2400 AGG_DATA_LOSS_COUNT
MMIO offset:0x2408 AGG_DATA_LOSS_TIMESTAMP
MMIO offset:0x2410 LAST_UPDATE_TIMESTAMP

Define event_group structures for both of these events and define the events
tracked by the aggregators in the file system code.

PMT_EVENT_ENERGY and PMT_EVENT_ACTIVITY are produced in fixed point
format. File system code must output as floating point values.

Signed-off-by: Tony Luck <tony.luck@intel.com>
Link: https://github.com/intel/Intel-PMT/blob/main/xml/CWF/OOBMSM/RMID-ENERGY/cwf_aggregator.xml # [1]
Link: https://github.com/intel/Intel-PMT/blob/main/xml/CWF/OOBMSM/RMID-PERF/cwf_aggregator.xml # [2]
---
include/linux/resctrl_types.h | 11 ++++
arch/x86/kernel/cpu/resctrl/intel_aet.c | 67 +++++++++++++++++++++++++
fs/resctrl/monitor.c | 35 +++++++------
3 files changed, 98 insertions(+), 15 deletions(-)

diff --git a/include/linux/resctrl_types.h b/include/linux/resctrl_types.h
index acfe07860b34..a5f56faa18d2 100644
--- a/include/linux/resctrl_types.h
+++ b/include/linux/resctrl_types.h
@@ -50,6 +50,17 @@ enum resctrl_event_id {
QOS_L3_MBM_TOTAL_EVENT_ID = 0x02,
QOS_L3_MBM_LOCAL_EVENT_ID = 0x03,

+ /* Intel Telemetry Events */
+ PMT_EVENT_ENERGY,
+ PMT_EVENT_ACTIVITY,
+ PMT_EVENT_STALLS_LLC_HIT,
+ PMT_EVENT_C1_RES,
+ PMT_EVENT_UNHALTED_CORE_CYCLES,
+ PMT_EVENT_STALLS_LLC_MISS,
+ PMT_EVENT_AUTO_C6_RES,
+ PMT_EVENT_UNHALTED_REF_CYCLES,
+ PMT_EVENT_UOPS_RETIRED,
+
/* Must be the last */
QOS_NUM_EVENTS,
};
diff --git a/arch/x86/kernel/cpu/resctrl/intel_aet.c b/arch/x86/kernel/cpu/resctrl/intel_aet.c
index 5d34c7349b02..bb080bdde190 100644
--- a/arch/x86/kernel/cpu/resctrl/intel_aet.c
+++ b/arch/x86/kernel/cpu/resctrl/intel_aet.c
@@ -13,6 +13,7 @@

#include <linux/array_size.h>
#include <linux/cleanup.h>
+#include <linux/compiler_types.h>
#include <linux/cpu.h>
#include <linux/err.h>
#include <linux/init.h>
@@ -20,11 +21,27 @@
#include <linux/intel_vsec.h>
#include <linux/overflow.h>
#include <linux/resctrl.h>
+#include <linux/resctrl_types.h>
#include <linux/stddef.h>
#include <linux/types.h>

#include "internal.h"

+/**
+ * struct pmt_event - Telemetry event.
+ * @id: Resctrl event id.
+ * @idx: Counter index within each per-RMID block of counters.
+ * @bin_bits: Zero for integer valued events, else number bits in fraction
+ * part of fixed-point.
+ */
+struct pmt_event {
+ enum resctrl_event_id id;
+ unsigned int idx;
+ unsigned int bin_bits;
+};
+
+#define EVT(_id, _idx, _bits) { .id = _id, .idx = _idx, .bin_bits = _bits }
+
/**
* struct event_group - Events with the same feature type ("energy" or "perf") and guid.
* @feature: Type of events, for example FEATURE_PER_RMID_PERF_TELEM or
@@ -35,14 +52,64 @@
* data for all telemetry regions type @feature.
* Valid if the system supports the event group.
* NULL otherwise.
+ * @guid: Unique number per XML description file.
+ * @mmio_size: Number of bytes of MMIO registers for this group.
+ * @num_events: Number of events in this group.
+ * @evts: Array of event descriptors.
*/
struct event_group {
/* Data fields for additional structures to manage this group. */
enum pmt_feature_id feature;
struct pmt_feature_group *pfg;
+
+ /* Remaining fields initialized from XML file. */
+ u32 guid;
+ size_t mmio_size;
+ unsigned int num_events;
+ struct pmt_event evts[] __counted_by(num_events);
+};
+
+#define XML_MMIO_SIZE(num_rmids, num_events, num_extra_status) \
+ (((num_rmids) * (num_events) + (num_extra_status)) * sizeof(u64))
+
+/*
+ * Link: https://github.com/intel/Intel-PMT
+ * File: xml/CWF/OOBMSM/RMID-ENERGY/cwf_aggregator.xml
+ */
+static struct event_group energy_0x26696143 = {
+ .feature = FEATURE_PER_RMID_ENERGY_TELEM,
+ .guid = 0x26696143,
+ .mmio_size = XML_MMIO_SIZE(576, 2, 3),
+ .num_events = 2,
+ .evts = {
+ EVT(PMT_EVENT_ENERGY, 0, 18),
+ EVT(PMT_EVENT_ACTIVITY, 1, 18),
+ }
+};
+
+/*
+ * Link: https://github.com/intel/Intel-PMT
+ * File: xml/CWF/OOBMSM/RMID-PERF/cwf_aggregator.xml
+ */
+static struct event_group perf_0x26557651 = {
+ .feature = FEATURE_PER_RMID_PERF_TELEM,
+ .guid = 0x26557651,
+ .mmio_size = XML_MMIO_SIZE(576, 7, 3),
+ .num_events = 7,
+ .evts = {
+ EVT(PMT_EVENT_STALLS_LLC_HIT, 0, 0),
+ EVT(PMT_EVENT_C1_RES, 1, 0),
+ EVT(PMT_EVENT_UNHALTED_CORE_CYCLES, 2, 0),
+ EVT(PMT_EVENT_STALLS_LLC_MISS, 3, 0),
+ EVT(PMT_EVENT_AUTO_C6_RES, 4, 0),
+ EVT(PMT_EVENT_UNHALTED_REF_CYCLES, 5, 0),
+ EVT(PMT_EVENT_UOPS_RETIRED, 6, 0),
+ }
};

static struct event_group *known_event_groups[] = {
+ &energy_0x26696143,
+ &perf_0x26557651,
};

#define for_each_event_group(_peg) \
diff --git a/fs/resctrl/monitor.c b/fs/resctrl/monitor.c
index 9c316b714968..df80eac48be6 100644
--- a/fs/resctrl/monitor.c
+++ b/fs/resctrl/monitor.c
@@ -958,27 +958,32 @@ static void dom_data_exit(struct rdt_resource *r)
mutex_unlock(&rdtgroup_mutex);
}

+#define MON_EVENT(_eventid, _name, _res, _fp) \
+ [_eventid] = { \
+ .name = _name, \
+ .evtid = _eventid, \
+ .rid = _res, \
+ .is_floating_point = _fp, \
+}
+
/*
* All available events. Architecture code marks the ones that
* are supported by a system using resctrl_enable_mon_event()
* to set .enabled.
*/
struct mon_evt mon_event_all[QOS_NUM_EVENTS] = {
- [QOS_L3_OCCUP_EVENT_ID] = {
- .name = "llc_occupancy",
- .evtid = QOS_L3_OCCUP_EVENT_ID,
- .rid = RDT_RESOURCE_L3,
- },
- [QOS_L3_MBM_TOTAL_EVENT_ID] = {
- .name = "mbm_total_bytes",
- .evtid = QOS_L3_MBM_TOTAL_EVENT_ID,
- .rid = RDT_RESOURCE_L3,
- },
- [QOS_L3_MBM_LOCAL_EVENT_ID] = {
- .name = "mbm_local_bytes",
- .evtid = QOS_L3_MBM_LOCAL_EVENT_ID,
- .rid = RDT_RESOURCE_L3,
- },
+ MON_EVENT(QOS_L3_OCCUP_EVENT_ID, "llc_occupancy", RDT_RESOURCE_L3, false),
+ MON_EVENT(QOS_L3_MBM_TOTAL_EVENT_ID, "mbm_total_bytes", RDT_RESOURCE_L3, false),
+ MON_EVENT(QOS_L3_MBM_LOCAL_EVENT_ID, "mbm_local_bytes", RDT_RESOURCE_L3, false),
+ MON_EVENT(PMT_EVENT_ENERGY, "core_energy", RDT_RESOURCE_PERF_PKG, true),
+ MON_EVENT(PMT_EVENT_ACTIVITY, "activity", RDT_RESOURCE_PERF_PKG, true),
+ MON_EVENT(PMT_EVENT_STALLS_LLC_HIT, "stalls_llc_hit", RDT_RESOURCE_PERF_PKG, false),
+ MON_EVENT(PMT_EVENT_C1_RES, "c1_res", RDT_RESOURCE_PERF_PKG, false),
+ MON_EVENT(PMT_EVENT_UNHALTED_CORE_CYCLES, "unhalted_core_cycles", RDT_RESOURCE_PERF_PKG, false),
+ MON_EVENT(PMT_EVENT_STALLS_LLC_MISS, "stalls_llc_miss", RDT_RESOURCE_PERF_PKG, false),
+ MON_EVENT(PMT_EVENT_AUTO_C6_RES, "c6_res", RDT_RESOURCE_PERF_PKG, false),
+ MON_EVENT(PMT_EVENT_UNHALTED_REF_CYCLES, "unhalted_ref_cycles", RDT_RESOURCE_PERF_PKG, false),
+ MON_EVENT(PMT_EVENT_UOPS_RETIRED, "uops_retired", RDT_RESOURCE_PERF_PKG, false),
};

void resctrl_enable_mon_event(enum resctrl_event_id eventid, bool any_cpu, unsigned int binary_bits)
--
2.51.1