perf list: Give more details about raw event encodings

List all the PMUs, not just the first core one, and list real format
specifiers with value ranges.

Before:

  $ perf list
  ...
    rNNN                                               [Raw hardware event descriptor]
    cpu/t1=v1[,t2=v2,t3 ...]/modifier                  [Raw hardware event descriptor]
         [(see 'man perf-list' on how to encode it)]
    mem:<addr>[/len][:access]                          [Hardware breakpoint]
  ...

After:

  $ perf list
  ...
    rNNN                                               [Raw event descriptor]
    cpu/event=0..255,pc,edge,.../modifier              [Raw event descriptor]
         [(see 'man perf-list' or 'man perf-record' on how to encode it)]
    breakpoint//modifier                               [Raw event descriptor]
    cstate_core/event=0..0xffffffffffffffff/modifier   [Raw event descriptor]
    cstate_pkg/event=0..0xffffffffffffffff/modifier    [Raw event descriptor]
    i915/i915_eventid=0..0x1fffff/modifier             [Raw event descriptor]
    intel_bts//modifier                                [Raw event descriptor]
    intel_pt/ptw,event,cyc_thresh=0..15,.../modifier   [Raw event descriptor]
    kprobe/retprobe/modifier                           [Raw event descriptor]
    msr/event=0..0xffffffffffffffff/modifier           [Raw event descriptor]
    power/event=0..255/modifier                        [Raw event descriptor]
    software//modifier                                 [Raw event descriptor]
    tracepoint//modifier                               [Raw event descriptor]
    uncore_arb/event=0..255,edge,inv,.../modifier      [Raw event descriptor]
    uncore_cbox/event=0..255,edge,inv,.../modifier     [Raw event descriptor]
    uncore_clock/event=0..255/modifier                 [Raw event descriptor]
    uncore_imc_free_running/event=0..255,umask=0..255/modifier[Raw event descriptor]
    uprobe/ref_ctr_offset=0..0xffffffff,retprobe/modifier[Raw event descriptor]
    mem:<addr>[/len][:access]                          [Hardware breakpoint]
  ...

With '--details' provide more details on the formats encoding:

  cpu/event=0..255,pc,edge,.../modifier              [Raw event descriptor]
       [(see 'man perf-list' or 'man perf-record' on how to encode it)]
        cpu/event=0..255,pc,edge,offcore_rsp=0..0xffffffffffffffff,ldlat=0..0xffff,inv,
        umask=0..255,frontend=0..0xffffff,cmask=0..255,config=0..0xffffffffffffffff,
        config1=0..0xffffffffffffffff,config2=0..0xffffffffffffffff,config3=0..0xffffffffffffffff,
        name=string,period=number,freq=number,branch_type=(u|k|hv|any|...),time,
        call-graph=(fp|dwarf|lbr),stack-size=number,max-stack=number,nr=number,inherit,no-inherit,
        overwrite,no-overwrite,percore,aux-output,aux-sample-size=number/modifier
  breakpoint//modifier                               [Raw event descriptor]
        breakpoint//modifier
  cstate_core/event=0..0xffffffffffffffff/modifier   [Raw event descriptor]
        cstate_core/event=0..0xffffffffffffffff/modifier
  cstate_pkg/event=0..0xffffffffffffffff/modifier    [Raw event descriptor]
        cstate_pkg/event=0..0xffffffffffffffff/modifier
  i915/i915_eventid=0..0x1fffff/modifier             [Raw event descriptor]
        i915/i915_eventid=0..0x1fffff/modifier
  intel_bts//modifier                                [Raw event descriptor]
        intel_bts//modifier
  intel_pt/ptw,event,cyc_thresh=0..15,.../modifier   [Raw event descriptor]
        intel_pt/ptw,event,cyc_thresh=0..15,pt,notnt,branch,tsc,pwr_evt,fup_on_ptw,cyc,noretcomp,
        mtc,psb_period=0..15,mtc_period=0..15/modifier
  kprobe/retprobe/modifier                           [Raw event descriptor]
        kprobe/retprobe/modifier
  msr/event=0..0xffffffffffffffff/modifier           [Raw event descriptor]
        msr/event=0..0xffffffffffffffff/modifier
  power/event=0..255/modifier                        [Raw event descriptor]
        power/event=0..255/modifier
  software//modifier                                 [Raw event descriptor]
        software//modifier
  tracepoint//modifier                               [Raw event descriptor]
        tracepoint//modifier
  uncore_arb/event=0..255,edge,inv,.../modifier      [Raw event descriptor]
        uncore_arb/event=0..255,edge,inv,umask=0..255,cmask=0..31/modifier
  uncore_cbox/event=0..255,edge,inv,.../modifier     [Raw event descriptor]
        uncore_cbox/event=0..255,edge,inv,umask=0..255,cmask=0..31/modifier
  uncore_clock/event=0..255/modifier                 [Raw event descriptor]
        uncore_clock/event=0..255/modifier
  uncore_imc_free_running/event=0..255,umask=0..255/modifier[Raw event descriptor]
        uncore_imc_free_running/event=0..255,umask=0..255/modifier
  uprobe/ref_ctr_offset=0..0xffffffff,retprobe/modifier[Raw event descriptor]
        uprobe/ref_ctr_offset=0..0xffffffff,retprobe/modifier

Committer notes:

Address this build error in various distros:

  55    58.44 ubuntu:24.04                  : FAIL gcc version 13.2.0 (Ubuntu 13.2.0-17ubuntu2)
    util/pmu.c:1638:70: error: '_Static_assert' with no message is a C2x extension [-Werror,-Wc2x-extensions]
     1638 |         _Static_assert(ARRAY_SIZE(terms) == __PARSE_EVENTS__TERM_TYPE_NR - 6);
          |                                                                             ^
          |                                                                             , ""
    1 error generated.

Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Tested-by: Kan Liang <kan.liang@linux.intel.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Cc: Yang Jihong <yangjihong1@huawei.com>
Link: https://lore.kernel.org/r/20240308001915.4060155-5-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/pmu.c

@@ -1603,6 +1603,62 @@ bool perf_pmu__has_format(const struct perf_pmu *pmu, const char *name)
 	return false;
 }
 
+int perf_pmu__for_each_format(struct perf_pmu *pmu, void *state, pmu_format_callback cb)
+{
+	static const char *const terms[] = {
+		"config=0..0xffffffffffffffff",
+		"config1=0..0xffffffffffffffff",
+		"config2=0..0xffffffffffffffff",
+		"config3=0..0xffffffffffffffff",
+		"name=string",
+		"period=number",
+		"freq=number",
+		"branch_type=(u|k|hv|any|...)",
+		"time",
+		"call-graph=(fp|dwarf|lbr)",
+		"stack-size=number",
+		"max-stack=number",
+		"nr=number",
+		"inherit",
+		"no-inherit",
+		"overwrite",
+		"no-overwrite",
+		"percore",
+		"aux-output",
+		"aux-sample-size=number",
+	};
+	struct perf_pmu_format *format;
+	int ret;
+
+	/*
+	 * max-events and driver-config are missing above as are the internal
+	 * types user, metric-id, raw, legacy cache and hardware. Assert against
+	 * the enum parse_events__term_type so they are kept in sync.
+	 */
+	_Static_assert(ARRAY_SIZE(terms) == __PARSE_EVENTS__TERM_TYPE_NR - 6,
+		       "perf_pmu__for_each_format()'s terms must be kept in sync with enum parse_events__term_type");
+	list_for_each_entry(format, &pmu->format, list) {
+		perf_pmu_format__load(pmu, format);
+		ret = cb(state, format->name, (int)format->value, format->bits);
+		if (ret)
+			return ret;
+	}
+	if (!pmu->is_core)
+		return 0;
+
+	for (size_t i = 0; i < ARRAY_SIZE(terms); i++) {
+		int config = PERF_PMU_FORMAT_VALUE_CONFIG;
+
+		if (i < PERF_PMU_FORMAT_VALUE_CONFIG_END)
+			config = i;
+
+		ret = cb(state, terms[i], config, /*bits=*/NULL);
+		if (ret)
+			return ret;
+	}
+	return 0;
+}
+
 bool is_pmu_core(const char *name)
 {
 	return !strcmp(name, "cpu") || !strcmp(name, "cpum_cf") || is_sysfs_pmu_core(name);
@@ -1697,8 +1753,12 @@ int perf_pmu__for_each_event(struct perf_pmu *pmu, bool skip_duplicate_pmus,
 	pmu_add_cpu_aliases(pmu);
 	list_for_each_entry(event, &pmu->aliases, list) {
 		size_t buf_used;
+		int pmu_name_len;
 
 		info.pmu_name = event->pmu_name ?: pmu->name;
+		pmu_name_len = skip_duplicate_pmus
+			? pmu_name_len_no_suffix(info.pmu_name, /*num=*/NULL)
+			: (int)strlen(info.pmu_name);
 		info.alias = NULL;
 		if (event->desc) {
 			info.name = event->name;
@@ -1723,7 +1783,7 @@ int perf_pmu__for_each_event(struct perf_pmu *pmu, bool skip_duplicate_pmus,
 		info.encoding_desc = buf + buf_used;
 		parse_events_terms__to_strbuf(&event->terms, &sb);
 		buf_used += snprintf(buf + buf_used, sizeof(buf) - buf_used,
-				"%s/%s/", info.pmu_name, sb.buf) + 1;
+				"%.*s/%s/", pmu_name_len, info.pmu_name, sb.buf) + 1;
 		info.topic = event->topic;
 		info.str = sb.buf;
 		info.deprecated = event->deprecated;

tools/perf/util/pmu.h

@@ -196,6 +196,8 @@ struct pmu_event_info {
 };
 
 typedef int (*pmu_event_callback)(void *state, struct pmu_event_info *info);
+typedef int (*pmu_format_callback)(void *state, const char *name, int config,
+				   const unsigned long *bits);
 
 void pmu_add_sys_aliases(struct perf_pmu *pmu);
 int perf_pmu__config(struct perf_pmu *pmu, struct perf_event_attr *attr,
@@ -215,6 +217,7 @@ int perf_pmu__find_event(struct perf_pmu *pmu, const char *event, void *state, p
 int perf_pmu__format_parse(struct perf_pmu *pmu, int dirfd, bool eager_load);
 void perf_pmu_format__set_value(void *format, int config, unsigned long *bits);
 bool perf_pmu__has_format(const struct perf_pmu *pmu, const char *name);
+int perf_pmu__for_each_format(struct perf_pmu *pmu, void *state, pmu_format_callback cb);
 
 bool is_pmu_core(const char *name);
 bool perf_pmu__supports_legacy_cache(const struct perf_pmu *pmu);

tools/perf/util/pmus.c

@@ -16,6 +16,7 @@
 #include "pmus.h"
 #include "pmu.h"
 #include "print-events.h"
+#include "strbuf.h"
 
 /*
  * core_pmus:  A PMU belongs to core_pmus if it's name is "cpu" or it's sysfs
@@ -503,6 +504,99 @@ void perf_pmus__print_pmu_events(const struct print_callbacks *print_cb, void *p
 	zfree(&aliases);
 }
 
+struct build_format_string_args {
+	struct strbuf short_string;
+	struct strbuf long_string;
+	int num_formats;
+};
+
+static int build_format_string(void *state, const char *name, int config,
+			       const unsigned long *bits)
+{
+	struct build_format_string_args *args = state;
+	unsigned int num_bits;
+	int ret1, ret2 = 0;
+
+	(void)config;
+	args->num_formats++;
+	if (args->num_formats > 1) {
+		strbuf_addch(&args->long_string, ',');
+		if (args->num_formats < 4)
+			strbuf_addch(&args->short_string, ',');
+	}
+	num_bits = bits ? bitmap_weight(bits, PERF_PMU_FORMAT_BITS) : 0;
+	if (num_bits <= 1) {
+		ret1 = strbuf_addf(&args->long_string, "%s", name);
+		if (args->num_formats < 4)
+			ret2 = strbuf_addf(&args->short_string, "%s", name);
+	} else if (num_bits > 8) {
+		ret1 = strbuf_addf(&args->long_string, "%s=0..0x%llx", name,
+				   ULLONG_MAX >> (64 - num_bits));
+		if (args->num_formats < 4) {
+			ret2 = strbuf_addf(&args->short_string, "%s=0..0x%llx", name,
+					   ULLONG_MAX >> (64 - num_bits));
+		}
+	} else {
+		ret1 = strbuf_addf(&args->long_string, "%s=0..%llu", name,
+				  ULLONG_MAX >> (64 - num_bits));
+		if (args->num_formats < 4) {
+			ret2 = strbuf_addf(&args->short_string, "%s=0..%llu", name,
+					   ULLONG_MAX >> (64 - num_bits));
+		}
+	}
+	return ret1 < 0 ? ret1 : (ret2 < 0 ? ret2 : 0);
+}
+
+void perf_pmus__print_raw_pmu_events(const struct print_callbacks *print_cb, void *print_state)
+{
+	bool skip_duplicate_pmus = print_cb->skip_duplicate_pmus(print_state);
+	struct perf_pmu *(*scan_fn)(struct perf_pmu *);
+	struct perf_pmu *pmu = NULL;
+
+	if (skip_duplicate_pmus)
+		scan_fn = perf_pmus__scan_skip_duplicates;
+	else
+		scan_fn = perf_pmus__scan;
+
+	while ((pmu = scan_fn(pmu)) != NULL) {
+		struct build_format_string_args format_args = {
+			.short_string = STRBUF_INIT,
+			.long_string = STRBUF_INIT,
+			.num_formats = 0,
+		};
+		int len = pmu_name_len_no_suffix(pmu->name, /*num=*/NULL);
+		const char *desc = "(see 'man perf-list' or 'man perf-record' on how to encode it)";
+
+		if (!pmu->is_core)
+			desc = NULL;
+
+		strbuf_addf(&format_args.short_string, "%.*s/", len, pmu->name);
+		strbuf_addf(&format_args.long_string, "%.*s/", len, pmu->name);
+		perf_pmu__for_each_format(pmu, &format_args, build_format_string);
+
+		if (format_args.num_formats > 3)
+			strbuf_addf(&format_args.short_string, ",.../modifier");
+		else
+			strbuf_addf(&format_args.short_string, "/modifier");
+
+		strbuf_addf(&format_args.long_string, "/modifier");
+		print_cb->print_event(print_state,
+				/*topic=*/NULL,
+				/*pmu_name=*/NULL,
+				format_args.short_string.buf,
+				/*event_alias=*/NULL,
+				/*scale_unit=*/NULL,
+				/*deprecated=*/false,
+				"Raw event descriptor",
+				desc,
+				/*long_desc=*/NULL,
+				format_args.long_string.buf);
+
+		strbuf_release(&format_args.short_string);
+		strbuf_release(&format_args.long_string);
+	}
+}
+
 bool perf_pmus__have_event(const char *pname, const char *name)
 {
 	struct perf_pmu *pmu = perf_pmus__find(pname);

tools/perf/util/pmus.h

@@ -18,6 +18,7 @@ struct perf_pmu *perf_pmus__scan_core(struct perf_pmu *pmu);
 const struct perf_pmu *perf_pmus__pmu_for_pmu_filter(const char *str);
 
 void perf_pmus__print_pmu_events(const struct print_callbacks *print_cb, void *print_state);
+void perf_pmus__print_raw_pmu_events(const struct print_callbacks *print_cb, void *print_state);
 bool perf_pmus__have_event(const char *pname, const char *name);
 int perf_pmus__num_core_pmus(void);
 bool perf_pmus__supports_extended_type(void);

tools/perf/util/print-events.c

@@ -39,7 +39,7 @@ static const char * const event_type_descriptors[] = {
 	"Software event",
 	"Tracepoint event",
 	"Hardware cache event",
-	"Raw hardware event descriptor",
+	"Raw event descriptor",
 	"Hardware breakpoint",
 };
 
@@ -416,8 +416,6 @@ void print_symbol_events(const struct print_callbacks *print_cb, void *print_sta
  */
 void print_events(const struct print_callbacks *print_cb, void *print_state)
 {
-	char *tmp;
-
 	print_symbol_events(print_cb, print_state, PERF_TYPE_HARDWARE,
 			event_symbols_hw, PERF_COUNT_HW_MAX);
 	print_symbol_events(print_cb, print_state, PERF_TYPE_SOFTWARE,
@@ -441,21 +439,7 @@ void print_events(const struct print_callbacks *print_cb, void *print_state)
 			/*long_desc=*/NULL,
 			/*encoding_desc=*/NULL);
 
-	if (asprintf(&tmp, "%s/t1=v1[,t2=v2,t3 ...]/modifier",
+	perf_pmus__print_raw_pmu_events(print_cb, print_state);
-		     perf_pmus__scan_core(/*pmu=*/NULL)->name) > 0) {
-		print_cb->print_event(print_state,
-				/*topic=*/NULL,
-				/*pmu_name=*/NULL,
-				tmp,
-				/*event_alias=*/NULL,
-				/*scale_unit=*/NULL,
-				/*deprecated=*/false,
-				event_type_descriptors[PERF_TYPE_RAW],
-				"(see 'man perf-list' on how to encode it)",
-				/*long_desc=*/NULL,
-				/*encoding_desc=*/NULL);
-		free(tmp);
-	}
 
 	print_cb->print_event(print_state,
 			/*topic=*/NULL,