perf topdown: Use attribute to see an event is a topdown metic or slots

The string comparisons were overly broad and could fire for the
incorrect PMU and events. Switch to using the config in the attribute
then add a perf test to confirm the attribute config values match
those of parsed events of that name and don't match others. This
exposed matches for slots events that shouldn't have matched as the
slots fixed counter event, such as topdown.slots_p.

Fixes: fbc798316bef ("perf x86/topdown: Refine helper arch_is_topdown_metrics()")
Signed-off-by: Ian Rogers <irogers@google.com>
Link: https://lore.kernel.org/r/20250719030517.1990983-14-irogers@google.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>

3 files changed, 26 insertions, 55 deletions

diff --git a/tools/perf/arch/x86/util/evsel.c b/tools/perf/arch/x86/util/evsel.c
index 3dd29ba2c23b..9bc80fff3aa0 100644
--- a/tools/perf/arch/x86/util/evsel.c
+++ b/tools/perf/arch/x86/util/evsel.c
@@ -23,47 +23,25 @@ void arch_evsel__set_sample_weight(struct evsel *evsel)
 bool evsel__sys_has_perf_metrics(const struct evsel *evsel)
 {
 	struct perf_pmu *pmu;
-	u32 type = evsel->core.attr.type;
 
-	/*
-	 * The PERF_TYPE_RAW type is the core PMU type, e.g., "cpu" PMU
-	 * on a non-hybrid machine, "cpu_core" PMU on a hybrid machine.
-	 * The slots event is only available for the core PMU, which
-	 * supports the perf metrics feature.
-	 * Checking both the PERF_TYPE_RAW type and the slots event
-	 * should be good enough to detect the perf metrics feature.
-	 */
-again:
-	switch (type) {
-	case PERF_TYPE_HARDWARE:
-	case PERF_TYPE_HW_CACHE:
-		type = evsel->core.attr.config >> PERF_PMU_TYPE_SHIFT;
-		if (type)
-			goto again;
-		break;
-	case PERF_TYPE_RAW:
-		break;
-	default:
+	if (!topdown_sys_has_perf_metrics())
 		return false;
-	}
-
-	pmu = evsel->pmu;
-	if (pmu && perf_pmu__is_fake(pmu))
-		pmu = NULL;
 
-	if (!pmu) {
-		while ((pmu = perf_pmus__scan_core(pmu)) != NULL) {
-			if (pmu->type == PERF_TYPE_RAW)
-				break;
-		}
-	}
-	return pmu && perf_pmu__have_event(pmu, "slots");
+	/*
+	 * The PERF_TYPE_RAW type is the core PMU type, e.g., "cpu" PMU on a
+	 * non-hybrid machine, "cpu_core" PMU on a hybrid machine.  The
+	 * topdown_sys_has_perf_metrics checks the slots event is only available
+	 * for the core PMU, which supports the perf metrics feature. Checking
+	 * both the PERF_TYPE_RAW type and the slots event should be good enough
+	 * to detect the perf metrics feature.
+	 */
+	pmu = evsel__find_pmu(evsel);
+	return pmu && pmu->type == PERF_TYPE_RAW;
 }
 
 bool arch_evsel__must_be_in_group(const struct evsel *evsel)
 {
-	if (!evsel__sys_has_perf_metrics(evsel) || !evsel->name ||
-	    strcasestr(evsel->name, "uops_retired.slots"))
+	if (!evsel__sys_has_perf_metrics(evsel))
 		return false;
 
 	return arch_is_topdown_metrics(evsel) || arch_is_topdown_slots(evsel);
diff --git a/tools/perf/arch/x86/util/topdown.c b/tools/perf/arch/x86/util/topdown.c
index d1c654839049..66b231fbf52e 100644
--- a/tools/perf/arch/x86/util/topdown.c
+++ b/tools/perf/arch/x86/util/topdown.c
@@ -1,6 +1,4 @@
 // SPDX-License-Identifier: GPL-2.0
-#include "api/fs/fs.h"
-#include "util/evsel.h"
 #include "util/evlist.h"
 #include "util/pmu.h"
 #include "util/pmus.h"
@@ -8,6 +6,9 @@
 #include "topdown.h"
 #include "evsel.h"
 
+// cmask=0, inv=0, pc=0, edge=0, umask=4, event=0
+#define TOPDOWN_SLOTS		0x0400
+
 /* Check whether there is a PMU which supports the perf metrics. */
 bool topdown_sys_has_perf_metrics(void)
 {
@@ -32,31 +33,19 @@ bool topdown_sys_has_perf_metrics(void)
 	return has_perf_metrics;
 }
 
-#define TOPDOWN_SLOTS		0x0400
 bool arch_is_topdown_slots(const struct evsel *evsel)
 {
-	if (evsel->core.attr.config == TOPDOWN_SLOTS)
-		return true;
-
-	return false;
+	return evsel->core.attr.type == PERF_TYPE_RAW &&
+	       evsel->core.attr.config == TOPDOWN_SLOTS &&
+	       evsel->core.attr.config1 == 0;
 }
 
 bool arch_is_topdown_metrics(const struct evsel *evsel)
 {
-	int config = evsel->core.attr.config;
-	const char *name_from_config;
-	struct perf_pmu *pmu;
-
-	/* All topdown events have an event code of 0. */
-	if ((config & 0xFF) != 0)
-		return false;
-
-	pmu = evsel__find_pmu(evsel);
-	if (!pmu || !pmu->is_core)
-		return false;
-
-	name_from_config = perf_pmu__name_from_config(pmu, config);
-	return name_from_config && strcasestr(name_from_config, "topdown");
+	// cmask=0, inv=0, pc=0, edge=0, umask=0x80-0x87, event=0
+	return evsel->core.attr.type == PERF_TYPE_RAW &&
+		(evsel->core.attr.config & 0xFFFFF8FF) == 0x8000 &&
+		evsel->core.attr.config1 == 0;
 }
 
 /*
diff --git a/tools/perf/arch/x86/util/topdown.h b/tools/perf/arch/x86/util/topdown.h
index 1bae9b1822d7..2349536cf882 100644
--- a/tools/perf/arch/x86/util/topdown.h
+++ b/tools/perf/arch/x86/util/topdown.h
@@ -2,6 +2,10 @@
 #ifndef _TOPDOWN_H
 #define _TOPDOWN_H 1
 
+#include <stdbool.h>
+
+struct evsel;
+
 bool topdown_sys_has_perf_metrics(void);
 bool arch_is_topdown_slots(const struct evsel *evsel);
 bool arch_is_topdown_metrics(const struct evsel *evsel);