diff --git a/include/spdk_internal/event.h b/include/spdk_internal/event.h
index 7be3a0ea1c..25bdc04eff 100644
--- a/include/spdk_internal/event.h
+++ b/include/spdk_internal/event.h
@@ -58,7 +58,14 @@ struct spdk_subsystem {
 	void (*init)(void);
 	void (*fini)(void);
 	void (*config)(FILE *fp);
-	void (*write_config_json)(struct spdk_json_write_ctx *w);
+
+	/**
+	 * Write JSON configuration handler.
+	 *
+	 * \param w JSON write context
+	 * \param done_ev Done event to be called when writing is done.
+	 */
+	void (*write_config_json)(struct spdk_json_write_ctx *w, struct spdk_event *done_ev);
 	TAILQ_ENTRY(spdk_subsystem) tailq;
 };
 
@@ -86,13 +93,17 @@ void spdk_subsystem_fini_next(void);
 void spdk_subsystem_config(FILE *fp);
 
 /**
- * Save pointed subsystem configuration to the JSON write context. In case of
- * error \c null is written to the JSON context.
+ * Save pointed \c subsystem configuration to the JSON write context \c w. In case of
+ * error \c null is written to the JSON context. Writing might be done in async way
+ * so caller need to pass event that subsystem will call when it finish writing
+ * configuration.
  *
  * \param w JSON write context
  * \param subsystem the subsystem to query
+ * \param done_ev event to be called when writing is done
  */
-void spdk_subsystem_config_json(struct spdk_json_write_ctx *w, struct spdk_subsystem *subsystem);
+void spdk_subsystem_config_json(struct spdk_json_write_ctx *w, struct spdk_subsystem *subsystem,
+				struct spdk_event *done_ev);
 
 void spdk_rpc_initialize(const char *listen_addr);
 void spdk_rpc_finish(void);
diff --git a/lib/event/rpc/subsystem_rpc.c b/lib/event/rpc/subsystem_rpc.c
index 36635e2bbe..c38b371a7f 100644
--- a/lib/event/rpc/subsystem_rpc.c
+++ b/lib/event/rpc/subsystem_rpc.c
@@ -35,6 +35,7 @@
 #include "spdk/rpc.h"
 #include "spdk/string.h"
 #include "spdk/util.h"
+#include "spdk/env.h"
 
 static void
 spdk_rpc_get_subsystems(struct spdk_jsonrpc_request *request,
@@ -84,6 +85,15 @@ static const struct spdk_json_object_decoder rpc_get_subsystem_config[] = {
 	{"name", offsetof(struct rpc_get_subsystem_config, name), spdk_json_decode_string},
 };
 
+static void
+rpc_get_subsystem_config_done(void *arg1, void *arg2)
+{
+	struct spdk_jsonrpc_request *request = arg1;
+	struct spdk_json_write_ctx *w = arg2;
+
+	spdk_jsonrpc_end_result(request, w);
+}
+
 static void
 spdk_rpc_get_subsystem_config(struct spdk_jsonrpc_request *request,
 			      const struct spdk_json_val *params)
@@ -91,6 +101,7 @@ spdk_rpc_get_subsystem_config(struct spdk_jsonrpc_request *request,
 	struct rpc_get_subsystem_config req = {};
 	struct spdk_json_write_ctx *w;
 	struct spdk_subsystem *subsystem;
+	struct spdk_event *ev;
 
 	if (spdk_json_decode_object(params, rpc_get_subsystem_config,
 				    SPDK_COUNTOF(rpc_get_subsystem_config), &req)) {
@@ -102,17 +113,17 @@ spdk_rpc_get_subsystem_config(struct spdk_jsonrpc_request *request,
 	if (!subsystem) {
 		spdk_jsonrpc_send_error_response_fmt(request, SPDK_JSONRPC_ERROR_INVALID_PARAMS,
 						     "Subsystem '%s' not found", req.name);
-		goto out;
+		free(req.name);
+		return;
 	}
 
+	free(req.name);
+
 	w = spdk_jsonrpc_begin_result(request);
 	if (w) {
-		spdk_subsystem_config_json(w, subsystem);
-		spdk_jsonrpc_end_result(request, w);
+		ev = spdk_event_allocate(spdk_env_get_current_core(), rpc_get_subsystem_config_done, request, w);
+		spdk_subsystem_config_json(w, subsystem, ev);
 	}
-
-out:
-	free(req.name);
 }
 
 SPDK_RPC_REGISTER("get_subsystem_config", spdk_rpc_get_subsystem_config)
diff --git a/lib/event/subsystem.c b/lib/event/subsystem.c
index 4c34544da0..438e7f543c 100644
--- a/lib/event/subsystem.c
+++ b/lib/event/subsystem.c
@@ -244,11 +244,13 @@ spdk_subsystem_config(FILE *fp)
 }
 
 void
-spdk_subsystem_config_json(struct spdk_json_write_ctx *w, struct spdk_subsystem *subsystem)
+spdk_subsystem_config_json(struct spdk_json_write_ctx *w, struct spdk_subsystem *subsystem,
+			   struct spdk_event *done_ev)
 {
 	if (subsystem && subsystem->write_config_json) {
-		subsystem->write_config_json(w);
+		subsystem->write_config_json(w, done_ev);
 	} else {
 		spdk_json_write_null(w);
+		spdk_event_call(done_ev);
 	}
 }
diff --git a/lib/event/subsystems/bdev/bdev.c b/lib/event/subsystems/bdev/bdev.c
index da58a6473f..e98ba351c0 100644
--- a/lib/event/subsystems/bdev/bdev.c
+++ b/lib/event/subsystems/bdev/bdev.c
@@ -64,12 +64,19 @@ spdk_bdev_subsystem_finish(void)
 	spdk_bdev_finish(spdk_bdev_subsystem_finish_done, NULL);
 }
 
+static void
+_spdk_bdev_subsystem_config_json(struct spdk_json_write_ctx *w, struct spdk_event *done_ev)
+{
+	spdk_bdev_subsystem_config_json(w);
+	spdk_event_call(done_ev);
+}
+
 static struct spdk_subsystem g_spdk_subsystem_bdev = {
 	.name = "bdev",
 	.init = spdk_bdev_subsystem_initialize,
 	.fini = spdk_bdev_subsystem_finish,
 	.config = spdk_bdev_config_text,
-	.write_config_json = spdk_bdev_subsystem_config_json,
+	.write_config_json = _spdk_bdev_subsystem_config_json,
 };
 
 SPDK_SUBSYSTEM_REGISTER(g_spdk_subsystem_bdev);