scripts/rpc.py: add method "get_nvme_controllers"

"get_nvme_controllers" can be used to list NVMe controllers.
Names and transport IDs of the NVMe controllers will be
reported by this method.

Change-Id: Ie59b567afc09e70475f97939e86a872af39c5d8a
Signed-off-by: Liu Xiaodong <xiaodong.liu@intel.com>
Reviewed-on: https://review.gerrithub.io/419094
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Reviewed-by: GangCao <gang.cao@intel.com>
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Chandler-Test-Pool: SPDK Automated Test System <sys_sgsw@intel.com>

doc/jsonrpc.md

@@ -1033,6 +1033,54 @@ Example response:
 }
 ~~~
 
+## get_nvme_controllers {#rpc_get_nvme_controllers}
+
+Get information about NVMe controllers.
+
+### Parameters
+
+The user may specify no parameters in order to list all NVMe controllers, or one NVMe controller may be
+specified by name.
+
+Name                    | Optional | Type        | Description
+----------------------- | -------- | ----------- | -----------
+name                    | Optional | string      | NVMe controller name
+
+### Response
+
+The response is an array of objects containing information about the requested NVMe controllers.
+
+### Example
+
+Example request:
+~~~
+{
+  "jsonrpc": "2.0",
+  "id": 1,
+  "method": "get_nvme_controllers",
+  "params": {
+    "name": "Nvme0"
+  }
+}
+~~~
+
+Example response:
+~~~
+{
+  "jsonrpc": "2.0",
+  "id": 1,
+  "result": [
+    {
+      "name": "Nvme0",
+      "trid": {
+        "trtype": "PCIe",
+        "traddr": "0000:05:00.0"
+      }
+    }
+  ]
+}
+~~~
+
 ## delete_nvme_controller {#rpc_delete_nvme_controller}
 
 Delete NVMe controller.

lib/bdev/nvme/bdev_nvme.c

@@ -156,6 +156,18 @@ spdk_bdev_nvme_lookup_ctrlr(const char *ctrlr_name)
 	return NULL;
 }
 
+struct nvme_ctrlr *
+spdk_bdev_nvme_first_ctrlr(void)
+{
+	return TAILQ_FIRST(&g_nvme_ctrlrs);
+}
+
+struct nvme_ctrlr *
+spdk_bdev_nvme_next_ctrlr(struct nvme_ctrlr *prev)
+{
+	return TAILQ_NEXT(prev, tailq);
+}
+
 static int
 bdev_nvme_get_ctx_size(void)
 {

lib/bdev/nvme/bdev_nvme.h

@@ -88,6 +88,8 @@ void spdk_bdev_nvme_dump_trid_json(struct spdk_nvme_transport_id *trid,
 
 struct spdk_nvme_qpair *spdk_bdev_nvme_get_io_qpair(struct spdk_io_channel *ctrlr_io_ch);
 struct nvme_ctrlr *spdk_bdev_nvme_lookup_ctrlr(const char *ctrlr_name);
+struct nvme_ctrlr *spdk_bdev_nvme_first_ctrlr(void);
+struct nvme_ctrlr *spdk_bdev_nvme_next_ctrlr(struct nvme_ctrlr *prev);
 void spdk_bdev_nvme_get_opts(struct spdk_bdev_nvme_opts *opts);
 int spdk_bdev_nvme_set_opts(const struct spdk_bdev_nvme_opts *opts);
 int spdk_bdev_nvme_set_hotplug(bool enabled, uint64_t period_us, spdk_thread_fn cb, void *cb_ctx);

lib/bdev/nvme/bdev_nvme_rpc.c

@@ -268,6 +268,90 @@ invalid:
 }
 SPDK_RPC_REGISTER("construct_nvme_bdev", spdk_rpc_construct_nvme_bdev, SPDK_RPC_RUNTIME)
 
+static void
+spdk_rpc_dump_nvme_controller_info(struct spdk_json_write_ctx *w,
+				   struct nvme_ctrlr *nvme_ctrlr)
+{
+	struct spdk_nvme_transport_id	*trid;
+
+	trid = &nvme_ctrlr->trid;
+
+	spdk_json_write_object_begin(w);
+	spdk_json_write_named_string(w, "name", nvme_ctrlr->name);
+
+	spdk_json_write_named_object_begin(w, "trid");
+	spdk_bdev_nvme_dump_trid_json(trid, w);
+	spdk_json_write_object_end(w);
+
+	spdk_json_write_object_end(w);
+}
+
+struct rpc_get_nvme_controllers {
+	char *name;
+};
+
+static void
+free_rpc_get_nvme_controllers(struct rpc_get_nvme_controllers *r)
+{
+	free(r->name);
+}
+
+static const struct spdk_json_object_decoder rpc_get_nvme_controllers_decoders[] = {
+	{"name", offsetof(struct rpc_get_nvme_controllers, name), spdk_json_decode_string, true},
+};
+
+static void
+spdk_rpc_get_nvme_controllers(struct spdk_jsonrpc_request *request,
+			      const struct spdk_json_val *params)
+{
+	struct rpc_get_nvme_controllers req = {};
+	struct spdk_json_write_ctx *w;
+	struct nvme_ctrlr *ctrlr = NULL;
+
+	if (params && spdk_json_decode_object(params, rpc_get_nvme_controllers_decoders,
+					      SPDK_COUNTOF(rpc_get_nvme_controllers_decoders),
+					      &req)) {
+		SPDK_ERRLOG("spdk_json_decode_object failed\n");
+		goto invalid;
+	}
+
+	if (req.name) {
+		ctrlr = spdk_bdev_nvme_lookup_ctrlr(req.name);
+		if (ctrlr == NULL) {
+			SPDK_ERRLOG("ctrlr '%s' does not exist\n", req.name);
+			goto invalid;
+		}
+	}
+
+	free_rpc_get_nvme_controllers(&req);
+	w = spdk_jsonrpc_begin_result(request);
+	if (w == NULL) {
+		return;
+	}
+
+	spdk_json_write_array_begin(w);
+
+	if (ctrlr != NULL) {
+		spdk_rpc_dump_nvme_controller_info(w, ctrlr);
+	} else {
+		for (ctrlr = spdk_bdev_nvme_first_ctrlr(); ctrlr; ctrlr = spdk_bdev_nvme_next_ctrlr(ctrlr))  {
+			spdk_rpc_dump_nvme_controller_info(w, ctrlr);
+		}
+	}
+
+	spdk_json_write_array_end(w);
+
+	spdk_jsonrpc_end_result(request, w);
+
+	return;
+
+invalid:
+	spdk_jsonrpc_send_error_response(request, SPDK_JSONRPC_ERROR_INVALID_PARAMS, "Invalid parameters");
+
+	free_rpc_get_nvme_controllers(&req);
+}
+SPDK_RPC_REGISTER("get_nvme_controllers", spdk_rpc_get_nvme_controllers, SPDK_RPC_RUNTIME)
+
 struct rpc_delete_nvme {
 	char *name;
 };

scripts/rpc.py

@@ -291,6 +291,16 @@ if __name__ == "__main__":
     p.add_argument('-n', '--subnqn', help='NVMe-oF target subnqn')
     p.set_defaults(func=construct_nvme_bdev)
 
+    @call_cmd
+    def get_nvme_controllers(args):
+        print_dict(rpc.nvme.get_nvme_controllers(args.client,
+                                                 name=args.name))
+
+    p = subparsers.add_parser(
+        'get_nvme_controllers', help='Display current NVMe controllers list or required NVMe controller')
+    p.add_argument('-n', '--name', help="Name of the NVMe controller. Example: Nvme0", required=False)
+    p.set_defaults(func=get_nvme_controllers)
+
     @call_cmd
     def delete_nvme_controller(args):
         rpc.bdev.delete_nvme_controller(args.client,

scripts/rpc/nvme.py

@@ -37,3 +37,18 @@ def send_nvme_cmd(client, name, cmd_type, data_direction, cmdbuf,
         params['timeout_ms'] = timeout_ms
 
     return client.call('send_nvme_cmd', params)
+
+
+def get_nvme_controllers(client, name=None):
+    """Get information about NVMe controllers.
+
+    Args:
+        name: NVMe controller name to query (optional; if omitted, query all NVMe controllers)
+
+    Returns:
+        List of NVMe controller information objects.
+    """
+    params = {}
+    if name:
+        params['name'] = name
+    return client.call('get_nvme_controllers', params)