selftests/verification: Add initial RV tests

Add a series of tests to validate the RV tracefs API and basic
functionality.

* available monitors:
    Check that all monitors (from the monitors folder) appear as
    available and have a description. Works with nested monitors.

* enable/disable:
    Enable and disable all monitors and validate both the enabled file
    and the enabled_monitors. Check that enabling container monitors
    enables all nested monitors.

* reactors:
    Set all reactors and validate the setting, also for nested monitors.

* wwnr with printk:
    wwnr is broken on purpose, run it with a load and check that the
    printk reactor works. Also validate disabling reacting_on or
    monitoring_on prevents reactions.

These tests use the ftracetest suite.

Acked-by: Nam Cao <namcao@linutronix.de>
Link: https://lore.kernel.org/r/20251017115203.140080-3-gmonaco@redhat.com
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>

MAINTAINERS

@@ -22498,6 +22498,7 @@ F:	Documentation/trace/rv/
 F:	include/linux/rv.h
 F:	include/rv/
 F:	kernel/trace/rv/
+F:	tools/testing/selftests/verification/
 F:	tools/verification/
 
 RUST

tools/testing/selftests/verification/.gitignore

@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0-only
+logs

tools/testing/selftests/verification/Makefile

@@ -0,0 +1,8 @@
+# SPDX-License-Identifier: GPL-2.0
+all:
+
+TEST_PROGS := verificationtest-ktap
+TEST_FILES := test.d settings
+EXTRA_CLEAN := $(OUTPUT)/logs/*
+
+include ../lib.mk

tools/testing/selftests/verification/config

@@ -0,0 +1 @@
+CONFIG_RV=y

tools/testing/selftests/verification/settings

@@ -0,0 +1 @@
+timeout=0

tools/testing/selftests/verification/test.d/functions

@@ -0,0 +1,39 @@
+check_requires() { # Check required files, monitors and reactors
+	for i in "$@" ; do
+		p=${i%:program}
+		m=${i%:monitor}
+		r=${i%:reactor}
+		if [ $p != $i ]; then
+			if ! which $p ; then
+				echo "Required program $p is not found."
+				exit_unresolved
+			fi
+		elif [ $m != $i ]; then
+			if ! grep -wq $m available_monitors ; then
+				echo "Required monitor $m is not configured."
+				exit_unsupported
+			fi
+		elif [ $r != $i ]; then
+			if ! grep -wq $r available_reactors ; then
+				echo "Required reactor $r is not configured."
+				exit_unsupported
+			fi
+		elif [ ! -e $i ]; then
+			echo "Required feature interface $i doesn't exist."
+			exit_unsupported
+		fi
+	done
+}
+
+initialize_system() { # Reset RV to initial-state
+	echo > enabled_monitors
+	for m in monitors/*; do
+		echo nop > $m/reactors || true
+	done
+	echo 1 > monitoring_on
+	echo 1 > reacting_on || true
+}
+
+finish_system() {
+	initialize_system
+}

tools/testing/selftests/verification/test.d/rv_monitor_enable_disable.tc

@@ -0,0 +1,75 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0-or-later
+# description: Test monitor enable/disable
+
+test_simple_monitor() {
+    local monitor="$1"
+    local prefix="$2" # nested monitors
+
+    echo 1 > "monitors/$prefix$monitor/enable"
+    grep -q "$monitor$" enabled_monitors
+
+    echo 0 > "monitors/$prefix$monitor/enable"
+    ! grep -q "$monitor$" enabled_monitors
+
+    echo "$monitor" >> enabled_monitors
+    grep -q 1 "monitors/$prefix$monitor/enable"
+
+    echo "!$monitor" >> enabled_monitors
+    grep -q 0 "monitors/$prefix$monitor/enable"
+}
+
+test_container_monitor() {
+    local monitor="$1"
+	local nested
+
+    echo 1 > "monitors/$monitor/enable"
+    grep -q "^$monitor$" enabled_monitors
+
+    for nested_dir in "monitors/$monitor"/*; do
+        [ -d "$nested_dir" ] || continue
+        nested=$(basename "$nested_dir")
+        grep -q "^$monitor:$nested$" enabled_monitors
+    done
+	test -n "$nested"
+
+    echo 0 > "monitors/$monitor/enable"
+    ! grep -q "^$monitor$" enabled_monitors
+
+    for nested_dir in "monitors/$monitor"/*; do
+        [ -d "$nested_dir" ] || continue
+        nested=$(basename "$nested_dir")
+        ! grep -q "^$monitor:$nested$" enabled_monitors
+    done
+
+    echo "$monitor" >> enabled_monitors
+    grep -q 1 "monitors/$monitor/enable"
+
+    for nested_dir in "monitors/$monitor"/*; do
+        [ -d "$nested_dir" ] || continue
+        nested=$(basename "$nested_dir")
+        grep -q "^$monitor:$nested$" enabled_monitors
+    done
+
+    echo "!$monitor" >> enabled_monitors
+    grep -q 0 "monitors/$monitor/enable"
+
+    for nested_dir in "monitors/$monitor"/*; do
+        [ -d "$nested_dir" ] || continue
+        nested=$(basename "$nested_dir")
+		test_simple_monitor "$nested" "$monitor/"
+    done
+}
+
+for monitor_dir in monitors/*; do
+    monitor=$(basename "$monitor_dir")
+
+    if find "$monitor_dir" -mindepth 1 -type d | grep -q .; then
+        test_container_monitor "$monitor"
+    else
+        test_simple_monitor "$monitor"
+    fi
+done
+
+! echo non_existent_monitor > enabled_monitors
+! grep -q "^non_existent_monitor$" enabled_monitors

tools/testing/selftests/verification/test.d/rv_monitor_reactor.tc

@@ -0,0 +1,68 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0-or-later
+# description: Test monitor reactor setting
+# requires: available_reactors
+
+test_monitor_reactor() {
+    local monitor="$1"
+    local prefix="$2" # nested monitors
+
+    while read -r reactor; do
+        [ "$reactor" = nop ] && continue
+
+        echo "$reactor" > "monitors/$prefix$monitor/reactors"
+        grep -q "\\[$reactor\\]" "monitors/$prefix$monitor/reactors"
+    done < available_reactors
+
+    echo nop > "monitors/$prefix$monitor/reactors"
+    grep -q "\\[nop\\]" "monitors/$prefix$monitor/reactors"
+}
+
+test_container_monitor() {
+    local monitor="$1"
+	local nested
+
+    while read -r reactor; do
+        [ "$reactor" = nop ] && continue
+
+        echo "$reactor" > "monitors/$monitor/reactors"
+        grep -q "\\[$reactor\\]" "monitors/$monitor/reactors"
+
+        for nested_dir in "monitors/$monitor"/*; do
+            [ -d "$nested_dir" ] || continue
+            nested=$(basename "$nested_dir")
+            grep -q "\\[$reactor\\]" "monitors/$monitor/$nested/reactors"
+        done
+    done < available_reactors
+	test -n "$nested"
+
+    echo nop > "monitors/$monitor/reactors"
+    grep -q "\\[nop\\]" "monitors/$monitor/reactors"
+
+    for nested_dir in "monitors/$monitor"/*; do
+        [ -d "$nested_dir" ] || continue
+        nested=$(basename "$nested_dir")
+        grep -q "\\[nop\\]" "monitors/$monitor/$nested/reactors"
+    done
+
+    for nested_dir in "monitors/$monitor"/*; do
+        [ -d "$nested_dir" ] || continue
+        nested=$(basename "$nested_dir")
+        test_monitor_reactor "$nested" "$monitor/"
+    done
+}
+
+for monitor_dir in monitors/*; do
+    monitor=$(basename "$monitor_dir")
+
+    if find "$monitor_dir" -mindepth 1 -type d | grep -q .; then
+        test_container_monitor "$monitor"
+    else
+        test_monitor_reactor "$monitor"
+    fi
+done
+
+monitor=$(ls /sys/kernel/tracing/rv/monitors -1 | head -n 1)
+test -f "monitors/$monitor/reactors"
+! echo non_existent_reactor > "monitors/$monitor/reactors"
+! grep -q "\\[non_existent_reactor\\]" "monitors/$monitor/reactors"

tools/testing/selftests/verification/test.d/rv_monitors_available.tc

@@ -0,0 +1,18 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0-or-later
+# description: Check available monitors
+
+for monitor_dir in monitors/*; do
+    monitor=$(basename "$monitor_dir")
+
+    grep -q "^$monitor$" available_monitors
+    grep -q . "$monitor_dir"/desc
+
+    for nested_dir in "$monitor_dir"/*; do
+        [ -d "$nested_dir" ] || continue
+        nested=$(basename "$nested_dir")
+
+        grep -q "^$monitor:$nested$" available_monitors
+		grep -q . "$nested_dir"/desc
+    done
+done

tools/testing/selftests/verification/test.d/rv_wwnr_printk.tc

@@ -0,0 +1,30 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0-or-later
+# description: Test wwnr monitor with printk reactor
+# requires: available_reactors wwnr:monitor printk:reactor stress-ng:program
+
+load() { # returns true if there was a reaction
+	local lines_before num
+	num=$((($(nproc) + 1) / 2))
+	lines_before=$(dmesg | wc -l)
+	stress-ng --cpu-sched "$num" --timer "$num" -t 5 -q
+	dmesg | tail -n $((lines_before + 1)) | grep -q "rv: monitor wwnr does not allow event"
+}
+
+echo 1 > monitors/wwnr/enable
+echo printk > monitors/wwnr/reactors
+
+load
+
+echo 0 > monitoring_on
+! load
+echo 1 > monitoring_on
+
+load
+
+echo 0 > reacting_on
+! load
+echo 1 > reacting_on
+
+echo nop > monitors/wwnr/reactors
+echo 0 > monitors/wwnr/enable

tools/testing/selftests/verification/verificationtest-ktap

@@ -0,0 +1,8 @@
+#!/bin/sh -e
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# ftracetest-ktap: Wrapper to integrate ftracetest with the kselftest runner
+#
+# Copyright (C) Arm Ltd., 2023
+
+../ftrace/ftracetest -K -v --rv ../verification