[PATCH v13 17/32] x86,fs/resctrl: Fill in details of events for guid 0x26696143 and 0x26557651

Tony Luck
2025-10-29T16:21:37Z

The Intel Clearwater Forest CPU supports two RMID-based PMT feature
groups documented in the xml/CWF/OOBMSM/RMID-ENERGY/cwf_aggregator.xml and
xml/CWF/OOBMSM/RMID-PERF/cwf_aggregator.xml files in the Intel PMT GIT repository
[1].

The struct pmt_feature_group provided by the INTEL_PMT_TELEMETRY driver lists the
guid and other information for each aggregator of a given type (energy or perf)
present on the system.

resctrl has a condensed form of the XML description in struct
event_group. An event group is enabled if the pfg field points
to a struct pmt_feature_group.

The counter offsets in 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 these events in the file system code and add the events
to the event_group structures.

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 # [1]
---
include/linux/resctrl_types.h | 11 +++++++
arch/x86/kernel/cpu/resctrl/intel_aet.c | 43 +++++++++++++++++++++++++
fs/resctrl/monitor.c | 35 +++++++++++---------
3 files changed, 74 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 02bbe7872fcf..5aec929c3441 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 - All information about a group of telemetry events.
* @feature: Argument to intel_pmt_get_regions_by_feature() to
@@ -36,6 +53,9 @@
* 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. */
@@ -44,8 +64,14 @@ struct event_group {

/* 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
@@ -53,6 +79,12 @@ struct event_group {
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),
+ }
};

/*
@@ -62,6 +94,17 @@ static struct event_group energy_0x26696143 = {
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[] = {
diff --git a/fs/resctrl/monitor.c b/fs/resctrl/monitor.c
index 7d1b65316bc8..ea7cc0a3340c 100644
--- a/fs/resctrl/monitor.c
+++ b/fs/resctrl/monitor.c
@@ -952,27 +952,32 @@ 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)
--
2.51.0