tools/rv: Allow rv list to filter for container

Add possibility to supply the container name to rv list:

  # rv list sched
  mon1
  mon2
  mon3

This lists only monitors in sched, without indentation.
Supplying -h, any option (string starting with -) or more than 1
argument will still print the usage.
Passing a non-existent container prints nothing and passing no container
continues to print all monitors, showing indentation for nested
monitors, reported after their container.

Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Juri Lelli <juri.lelli@redhat.com>
Link: https://lore.kernel.org/20250305140406.350227-10-gmonaco@redhat.com
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

1 files changed, 27 insertions, 9 deletions

diff --git a/tools/verification/rv/src/in_kernel.c b/tools/verification/rv/src/in_kernel.c
index 032b85101929..c0dcee795c0d 100644
--- a/tools/verification/rv/src/in_kernel.c
+++ b/tools/verification/rv/src/in_kernel.c
@@ -180,19 +180,25 @@ static char *ikm_read_desc(char *monitor_name)
 /*
  * ikm_fill_monitor_definition - fill monitor's definition
  *
- * Returns -1 on error, 0 otherwise.
+ * Returns -1 on error, 1 if the monitor does not belong in the container, 0 otherwise.
+ * container can be NULL
  */
-static int ikm_fill_monitor_definition(char *name, struct monitor *ikm)
+static int ikm_fill_monitor_definition(char *name, struct monitor *ikm, char *container)
 {
 	int enabled;
 	char *desc, *nested_name;
 
 	nested_name = strstr(name, ":");
 	if (nested_name) {
+		/* it belongs in container if it starts with "container:" */
+		if (container && strstr(name, container) != name)
+			return 1;
 		*nested_name = '/';
 		++nested_name;
 		ikm->nested = 1;
 	} else {
+		if (container)
+			return 1;
 		nested_name = name;
 		ikm->nested = 0;
 	}
@@ -328,12 +334,12 @@ static int ikm_has_id(char *monitor_name)
  *
  * Returns 0 on success, -1 otherwise.
  */
-int ikm_list_monitors(void)
+int ikm_list_monitors(char *container)
 {
 	char *available_monitors;
 	struct monitor ikm = {0};
 	char *curr, *next;
-	int retval;
+	int retval, list_monitor = 0;
 
 	available_monitors = tracefs_instance_file_read(NULL, "rv/available_monitors", NULL);
 
@@ -347,17 +353,29 @@ int ikm_list_monitors(void)
 		next = strstr(curr, "\n");
 		*next = '\0';
 
-		retval = ikm_fill_monitor_definition(curr, &ikm);
-		if (retval)
+		retval = ikm_fill_monitor_definition(curr, &ikm, container);
+		if (retval < 0)
 			err_msg("ikm: error reading %d in kernel monitor, skipping\n", curr);
 
-		printf("%s%-*s %s %s\n", ikm.nested ? " - " : "",
-		       ikm.nested ? MAX_DA_NAME_LEN - 3 : MAX_DA_NAME_LEN,
-		       ikm.name, ikm.desc, ikm.enabled ? "[ON]" : "[OFF]");
+		if (!retval) {
+			int indent = ikm.nested && !container;
+
+			list_monitor = 1;
+			printf("%s%-*s %s %s\n", indent ? " - " : "",
+			       indent ? MAX_DA_NAME_LEN - 3 : MAX_DA_NAME_LEN,
+			       ikm.name, ikm.desc, ikm.enabled ? "[ON]" : "[OFF]");
+		}
 		curr = ++next;
 
 	} while (strlen(curr));
 
+	if (!list_monitor) {
+		if (container)
+			printf("-- No monitor found in container %s --\n", container);
+		else
+			printf("-- No monitor found --\n");
+	}
+
 	free(available_monitors);
 
 	return 0;