[v4,11/11] trace: enable trace operations via telemetry

diff --git a/doc/guides/prog_guide/trace_lib.rst b/doc/guides/prog_guide/trace_lib.rst
index 9a8f38073d..b7abf8e640 100644
--- a/doc/guides/prog_guide/trace_lib.rst
+++ b/doc/guides/prog_guide/trace_lib.rst
@@ -233,6 +233,45 @@  This section steps you through the details of generating trace and viewing it.
 
     babeltrace $HOME/dpdk-traces/rte-yyyy-mm-dd-[AP]M-hh-mm-ss/
 
+Configuring traces on a running DPDK application
+------------------------------------------------
+
+The DPDK trace library can be configured using the Telemetry interface.
+
+Examples::
+
+  --> /trace/list,lib.ethdev.*
+  {"/trace/list": {"lib.ethdev.configure": "Disabled",
+      "lib.ethdev.rxq.setup": "Disabled",
+      "lib.ethdev.txq.setup": "Disabled",
+      "lib.ethdev.start": "Disabled",
+      "lib.ethdev.stop": "Disabled",
+      "lib.ethdev.close": "Disabled",
+      "lib.ethdev.rx.burst": "Disabled",
+      "lib.ethdev.tx.burst": "Disabled"}}
+
+  --> /trace/enable,lib.ethdev.st*
+  {"/trace/enable": {"Count": 2}}
+  --> /trace/enable,lib.ethdev.st*
+  {"/trace/enable": {"Count": 0}}
+
+  --> /trace/list,lib.ethdev.*
+  {"/trace/list": {"lib.ethdev.configure": "Disabled",
+      "lib.ethdev.rxq.setup": "Disabled",
+      "lib.ethdev.txq.setup": "Disabled",
+      "lib.ethdev.start": "Enabled",
+      "lib.ethdev.stop": "Enabled",
+      "lib.ethdev.close": "Disabled",
+      "lib.ethdev.rx.burst": "Disabled",
+      "lib.ethdev.tx.burst": "Disabled"}}
+
+  --> /trace/save
+  {"/trace/save": {"Status": "OK",
+      "Path": ".../dpdk-traces/rte-2022-10-12-AM-10-51-48"}}
+
+For more information on how to use the Telemetry interface, see
+the :doc:`../howto/telemetry`.
+
 Implementation details
 ----------------------
 
diff --git a/lib/eal/common/eal_common_trace.c b/lib/eal/common/eal_common_trace.c
index 42f2c28c23..3c7c666269 100644
--- a/lib/eal/common/eal_common_trace.c
+++ b/lib/eal/common/eal_common_trace.c
@@ -12,6 +12,7 @@ 
 #include <rte_lcore.h>
 #include <rte_per_lcore.h>
 #include <rte_string_fns.h>
+#include <rte_telemetry.h>
 
 #include "eal_trace.h"
 
@@ -528,3 +529,80 @@  __rte_trace_point_register(rte_trace_point_t *handle, const char *name,
 
 	return -rte_errno;
 }
+
+static int
+trace_telemetry_enable(const char *cmd __rte_unused,
+	const char *params, struct rte_tel_data *d)
+{
+	unsigned int count;
+
+	if (params == NULL || strlen(params) == 0)
+		return -1;
+	rte_tel_data_start_dict(d);
+	count = __atomic_load_n(&trace.status, __ATOMIC_RELAXED);
+	rte_trace_pattern(params, true);
+	rte_tel_data_add_dict_int(d, "Count",
+		__atomic_load_n(&trace.status, __ATOMIC_RELAXED) - count);
+	return 0;
+
+}
+
+static int
+trace_telemetry_disable(const char *cmd __rte_unused,
+	const char *params, struct rte_tel_data *d)
+{
+	unsigned int count;
+
+	if (params == NULL || strlen(params) == 0)
+		return -1;
+	rte_tel_data_start_dict(d);
+	count = __atomic_load_n(&trace.status, __ATOMIC_RELAXED);
+	rte_trace_pattern(params, false);
+	rte_tel_data_add_dict_int(d, "Count",
+		count - __atomic_load_n(&trace.status, __ATOMIC_RELAXED));
+	return 0;
+
+}
+
+static int
+trace_telemetry_list(const char *cmd __rte_unused,
+	const char *params, struct rte_tel_data *d)
+{
+	struct trace_point *tp;
+
+	rte_tel_data_start_dict(d);
+	STAILQ_FOREACH(tp, &tp_list, next) {
+		if (params != NULL && fnmatch(params, tp->name, 0) != 0)
+			continue;
+
+		rte_tel_data_add_dict_string(d, tp->name,
+			rte_trace_point_is_enabled(tp->handle) ?  "Enabled" : "Disabled");
+	}
+
+	return 0;
+}
+
+static int
+trace_telemetry_save(const char *cmd __rte_unused,
+	const char *params __rte_unused, struct rte_tel_data *d)
+{
+	struct trace *trace = trace_obj_get();
+
+	rte_tel_data_start_dict(d);
+	rte_tel_data_add_dict_string(d, "Status", rte_trace_save() == 0 ? "OK" : "KO");
+	rte_tel_data_add_dict_string(d, "Path", trace->dir);
+
+	return 0;
+}
+
+RTE_INIT(trace_telemetry)
+{
+	rte_telemetry_register_cmd("/trace/enable", trace_telemetry_enable,
+		"Enable trace points matching the provided pattern. Parameters: string pattern.");
+	rte_telemetry_register_cmd("/trace/disable", trace_telemetry_disable,
+		"Disable trace points matching the provided pattern. Parameters: string pattern.");
+	rte_telemetry_register_cmd("/trace/list", trace_telemetry_list,
+		"List trace points. Parameters: string pattern.");
+	rte_telemetry_register_cmd("/trace/save", trace_telemetry_save,
+		"Save current traces. Takes no parameter.");
+}
diff --git a/lib/telemetry/telemetry_data.c b/lib/telemetry/telemetry_data.c
index 34366ecee3..5b319c18fb 100644
--- a/lib/telemetry/telemetry_data.c
+++ b/lib/telemetry/telemetry_data.c
@@ -106,6 +106,7 @@  valid_name(const char *name)
 			['a' ... 'z'] = 1,
 			['_'] = 1,
 			['/'] = 1,
+			['.'] = 1,
 	};
 	while (*name != '\0') {
 		if ((size_t)*name >= RTE_DIM(allowed) || allowed[(int)*name] == 0)