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

Reinette Chatre
2025-12-02T16:20:04Z

Hi Tony,

On 11/24/25 10:53 AM, Tony Luck wrote:
> 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.

(line length)

>
> 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

" these events " -> "these aggregator types"?

> 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

Can these links be fixed also? Appending the "File" to "Link" results in invalid url.

> + */
> +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

same here.

> + */
> +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) \

Reinette