subsystem/accel: add entry point for .write_config_json

Write config json for setting the selected accel module.

Signed-off-by: paul luse <paul.e.luse@intel.com>
Change-Id: Ife11d4d4a776254b56fa6d24dc817481beb78c3c
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/664
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Shuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
Reviewed-by: Tomasz Zawadzki <tomasz.zawadzki@intel.com>

include/spdk/accel_engine.h

@@ -140,6 +140,15 @@ int spdk_accel_submit_fill(struct spdk_accel_task *accel_req, struct spdk_io_cha
  */
 size_t spdk_accel_task_size(void);
 
+struct spdk_json_write_ctx;
+
+/**
+ * Write Acceleration subsystem configuration into provided JSON context.
+ *
+ * \param w JSON write context
+ */
+void spdk_accel_write_config_json(struct spdk_json_write_ctx *w);
+
 #ifdef __cplusplus
 }
 #endif

lib/accel/accel_engine.c

@@ -39,6 +39,7 @@
 #include "spdk/event.h"
 #include "spdk/log.h"
 #include "spdk/thread.h"
+#include "spdk/json.h"
 
 /* Accelerator Engine Framework: The following provides a top level
  * generic API for the accelerator functions defined here. Modules,
@@ -230,6 +231,19 @@ spdk_accel_engine_module_finish_cb(void)
 	g_fini_cb_arg = NULL;
 }
 
+void
+spdk_accel_write_config_json(struct spdk_json_write_ctx *w)
+{
+	spdk_json_write_array_begin(w);
+	spdk_json_write_object_begin(w);
+	spdk_json_write_named_string(w, "method", "accel_set_module");
+	spdk_json_write_named_object_begin(w, "params");
+	spdk_json_write_named_uint32(w, "module",  g_active_accel_module);
+	spdk_json_write_object_end(w);
+	spdk_json_write_object_end(w);
+	spdk_json_write_array_end(w);
+}
+
 void
 spdk_accel_engine_module_finish(void)
 {

module/event/subsystems/accel/accel.c

@@ -60,11 +60,18 @@ spdk_accel_engine_subsystem_finish(void)
 	spdk_accel_engine_finish(spdk_accel_engine_subsystem_finish_done, NULL);
 }
 
+static void
+spdk_accel_engine_subsystem_write_config_json(struct spdk_json_write_ctx *w)
+{
+	spdk_accel_write_config_json(w);
+}
+
 static struct spdk_subsystem g_spdk_subsystem_accel = {
 	.name = "accel",
 	.init = spdk_accel_engine_subsystem_initialize,
 	.fini = spdk_accel_engine_subsystem_finish,
 	.config = spdk_accel_engine_config_text,
+	.write_config_json = spdk_accel_engine_subsystem_write_config_json,
 };
 
 SPDK_SUBSYSTEM_REGISTER(g_spdk_subsystem_accel);

test/json_config/alias_rpc/conf.json

@@ -2,7 +2,7 @@
   "subsystems": [
     {
       "subsystem": "accel",
-      "config": null
+      "config": []
     },
     {
       "subsystem": "interface",

test/json_config/config_filter.py

@@ -23,6 +23,7 @@ def sort_json_object(o):
 
 def filter_methods(do_remove_global_rpcs):
     global_rpcs = [
+        'accel_set_module',
         'iscsi_set_options',
         'nvmf_set_config',
         'nvmf_set_max_subsystems',