rpc: add method for listing PCI devices

This RPC lists all PCI devices attached to an SPDK application.  Each
device is identified by a BDF and contains a buffer with a copy of its
config space.

Signed-off-by: Konrad Sztyber <konrad.sztyber@intel.com>
Change-Id: I852f421fde105d975458f8e63b8da4f92ed2c69b
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/10652
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Reviewed-by: Aleksey Marchuk <alexeymar@mellanox.com>
Community-CI: Mellanox Build Bot

doc/jsonrpc.md

@@ -9095,3 +9095,47 @@ Example response:
   }
 }
 ~~
+
+### framework_get_pci_devices
+
+List PCIe devices attached to an SPDK application and the contents of their config space.
+
+#### Parameters
+
+This method has no parameters.
+
+#### Response
+
+The response is an array of attached PCIe devices.
+
+#### Example
+
+Example request:
+~~
+{
+  "jsonrpc": "2.0",
+  "id": 1,
+  "method": "framework_get_pci_devices"
+}
+~~
+
+Example response:
+Note that the config space buffer was trimmed.
+~~
+{
+  "jsonrpc": "2.0",
+  "id": 1,
+  "result": {
+    [
+      {
+        "address": "0000:00:04.0",
+        "config_space": "8680455807051000...0000000000000000"
+      },
+      {
+        "address": "0000:00:03.0",
+        "config_space": "8680455807051000...0000000000000000"
+      }
+    ]
+  }
+}
+~~

lib/init/subsystem_rpc.c

@@ -35,6 +35,7 @@
 #include "spdk/string.h"
 #include "spdk/util.h"
 #include "spdk/env.h"
+#include "spdk/log.h"
 
 #include "spdk_internal/init.h"
 
@@ -119,3 +120,55 @@ rpc_framework_get_config(struct spdk_jsonrpc_request *request,
 
 SPDK_RPC_REGISTER("framework_get_config", rpc_framework_get_config, SPDK_RPC_RUNTIME)
 SPDK_RPC_REGISTER_ALIAS_DEPRECATED(framework_get_config, get_subsystem_config)
+
+static void
+dump_pci_device(void *ctx, struct spdk_pci_device *dev)
+{
+	struct spdk_json_write_ctx *w = ctx;
+	struct spdk_pci_addr addr;
+	char config[4096], bdf[14];
+	int rc;
+
+	addr = spdk_pci_device_get_addr(dev);
+	spdk_pci_addr_fmt(bdf, sizeof(bdf), &addr);
+
+	rc = spdk_pci_device_cfg_read(dev, config, sizeof(config), 0);
+	if (rc != 0) {
+		SPDK_ERRLOG("Failed to read config space of device: %s\n", bdf);
+		return;
+	}
+
+	spdk_json_write_object_begin(w);
+	spdk_json_write_named_string(w, "address", bdf);
+
+	/* Don't write the extended config space if it's all zeroes */
+	if (spdk_mem_all_zero(&config[256], sizeof(config) - 256)) {
+		spdk_json_write_named_bytearray(w, "config_space", config, 256);
+	} else {
+		spdk_json_write_named_bytearray(w, "config_space", config, sizeof(config));
+	}
+
+	spdk_json_write_object_end(w);
+}
+
+static void
+rpc_framework_get_pci_devices(struct spdk_jsonrpc_request *request,
+			      const struct spdk_json_val *params)
+{
+	struct spdk_json_write_ctx *w;
+
+	if (params != NULL) {
+		spdk_jsonrpc_send_error_response(request, SPDK_JSONRPC_ERROR_INVALID_PARAMS,
+						 "framework_get_pci_devices doesn't accept any parameters.\n");
+		return;
+	}
+
+	w = spdk_jsonrpc_begin_result(request);
+
+	spdk_json_write_array_begin(w);
+	spdk_pci_for_each_device(w, dump_pci_device);
+	spdk_json_write_array_end(w);
+
+	spdk_jsonrpc_end_result(request, w);
+}
+SPDK_RPC_REGISTER("framework_get_pci_devices", rpc_framework_get_pci_devices, SPDK_RPC_RUNTIME)

scripts/rpc.py

@@ -2690,6 +2690,12 @@ Format: 'user:u1 secret:s1 muser:mu1 msecret:ms1,user:u2 secret:s2 muser:mu2 mse
     p.add_argument('-i', '--impl', help='Socket implementation name, e.g. posix', required=True)
     p.set_defaults(func=sock_set_default_impl)
 
+    def framework_get_pci_devices(args):
+        print_json(rpc.subsystem.framework_get_pci_devices(args.client))
+
+    p = subparsers.add_parser('framework_get_pci_devices', help='''Get a list of attached PCI devices''')
+    p.set_defaults(func=framework_get_pci_devices)
+
     def check_called_name(name):
         if name in deprecated_aliases:
             print("{} is deprecated, use {} instead.".format(name, deprecated_aliases[name]), file=sys.stderr)

scripts/rpc/subsystem.py

@@ -10,3 +10,7 @@ def framework_get_subsystems(client):
 def framework_get_config(client, name):
     params = {'name': name}
     return client.call('framework_get_config', params)
+
+
+def framework_get_pci_devices(client):
+    return client.call('framework_get_pci_devices')