idxd/rpc: Revise the rpc function to use kernel or user driver

This patch is used to add the support for users to configure
use kernel or userspace idxd library.

Change-Id: Ie159b897bc9595894ad8f333168efaea6c2a3d78
Signed-off-by: Ziye Yang <ziye.yang@intel.com>
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/7332
Community-CI: Broadcom CI <spdk-ci.pdl@broadcom.com>
Community-CI: Mellanox Build Bot
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Shuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
Reviewed-by: Changpeng Liu <changpeng.liu@intel.com>
Reviewed-by: Aleksey Marchuk <alexeymar@mellanox.com>

CHANGELOG.md

@@ -95,6 +95,9 @@ Rados Cluster names.
 Revised a parameter `--stripe-size_kb` to `--stripe-size-kb` of `bdev_raid_create` method
 provided in `scripts/rpc.py` for consistency.
 
+An new optional parameter `config_kernel_mode` was added to the RPC `idxd_scan_accel_engine`,
+and this is used to enable using the kernel mode IDXD driver.
+
 ### bdev
 
 Removed ZCOPY emulation: The bdev module can be checked to see if it supports ZCOPY

doc/jsonrpc.md

@@ -1407,6 +1407,7 @@ This feature is considered as experimental.
 Name                    | Optional | Type        | Description
 ----------------------- | -------- | ----------- | -----------
 config_number           | Required | number      | Pre-defined config # to use (ie 0, 1). See [docs.](https://spdk.io/doc/idxd.html)
+config_kernel_mode      | Optional | Boolean     | If set, will use kernel idxd driver.
 
 ### Example
 
@@ -1415,7 +1416,8 @@ Example request:
 ~~~
 {
   "params": {
-    "config_number": 0
+    "config_number": 0,
+    "config_kernel_mode": false
   },
   "jsonrpc": "2.0",
   "method": "idxd_scan_accel_engine",

include/spdk/idxd.h

@@ -117,8 +117,9 @@ void spdk_idxd_detach(struct spdk_idxd_device *idxd);
  * Sets the IDXD configuration.
  *
  * \param config_number the configuration number for a valid IDXD config.
+ * \param kernel_mode true if using kernel driver.
   */
-void spdk_idxd_set_config(uint32_t config_number);
+void spdk_idxd_set_config(uint32_t config_number, bool kernel_mode);
 
 /**
  * Return the max number of descriptors per batch for IDXD.

lib/idxd/idxd.c

@@ -46,6 +46,7 @@
 
 #define ALIGN_4K 0x1000
 #define USERSPACE_DRIVER_NAME "user"
+#define KERNEL_DRIVER_NAME "kernel"
 #define CHAN_PER_DEVICE(total_wq_size) ((total_wq_size >= 128) ? 8 : 4)
 /*
  * Need to limit how many completions we reap in one poller to avoid starving
@@ -257,9 +258,13 @@ idxd_get_impl_by_name(const char *impl_name)
 
 /* Called via RPC to select a pre-defined configuration. */
 void
-spdk_idxd_set_config(uint32_t config_num)
+spdk_idxd_set_config(uint32_t config_num, bool kernel_mode)
 {
-	g_idxd_impl = idxd_get_impl_by_name(USERSPACE_DRIVER_NAME);
+	if (kernel_mode) {
+		g_idxd_impl = idxd_get_impl_by_name(KERNEL_DRIVER_NAME);
+	} else {
+		g_idxd_impl = idxd_get_impl_by_name(USERSPACE_DRIVER_NAME);
+	}
 
 	if (g_idxd_impl == NULL) {
 		SPDK_ERRLOG("Cannot set the idxd implementation");

module/accel/idxd/accel_engine_idxd.c

@@ -47,6 +47,7 @@
 #include "spdk/json.h"
 
 static bool g_idxd_enable = false;
+static bool g_kernel_mode = false;
 uint32_t g_config_number;
 static uint32_t g_batch_max;
 
@@ -345,7 +346,7 @@ attach_cb(void *cb_ctx, struct spdk_idxd_device *idxd)
 }
 
 void
-accel_engine_idxd_enable_probe(uint32_t config_number)
+accel_engine_idxd_enable_probe(uint32_t config_number, bool kernel_mode)
 {
 	if (config_number > IDXD_MAX_CONFIG_NUM) {
 		SPDK_ERRLOG("Invalid config number, using default of 0\n");
@@ -353,8 +354,9 @@ accel_engine_idxd_enable_probe(uint32_t config_number)
 	}
 
 	g_config_number = config_number;
+	g_kernel_mode = kernel_mode;
 	g_idxd_enable = true;
-	spdk_idxd_set_config(g_config_number);
+	spdk_idxd_set_config(g_config_number, g_kernel_mode);
 }
 
 static int
@@ -410,6 +412,7 @@ accel_engine_idxd_write_config_json(struct spdk_json_write_ctx *w)
 		spdk_json_write_named_string(w, "method", "idxd_scan_accel_engine");
 		spdk_json_write_named_object_begin(w, "params");
 		spdk_json_write_named_uint32(w, "config_number", g_config_number);
+		spdk_json_write_named_uint32(w, "config_kernel_mode", g_kernel_mode);
 		spdk_json_write_object_end(w);
 		spdk_json_write_object_end(w);
 	}

module/accel/idxd/accel_engine_idxd.h

@@ -38,6 +38,6 @@
 
 #define IDXD_MAX_DEVICES	16
 
-void accel_engine_idxd_enable_probe(uint32_t config_number);
+void accel_engine_idxd_enable_probe(uint32_t config_number, bool kernel_mode);
 
 #endif /* SPDK_ACCEL_ENGINE_IDXD_H */

module/accel/idxd/accel_engine_idxd_rpc.c

@@ -41,10 +41,12 @@
 
 struct rpc_idxd_scan_accel_engine {
 	uint32_t config_number;
+	bool config_kernel_mode;
 };
 
 static const struct spdk_json_object_decoder rpc_idxd_scan_accel_engine_decoder[] = {
 	{"config_number", offsetof(struct rpc_idxd_scan_accel_engine, config_number), spdk_json_decode_uint32},
+	{"config_kernel_mode", offsetof(struct rpc_idxd_scan_accel_engine, config_kernel_mode), spdk_json_decode_bool, true},
 };
 
 static void
@@ -64,9 +66,13 @@ rpc_idxd_scan_accel_engine(struct spdk_jsonrpc_request *request,
 		}
 	}
 
-	SPDK_NOTICELOG("Enabling IDXD with config #%u\n", req.config_number);
-	accel_engine_idxd_enable_probe(req.config_number);
+	if (req.config_kernel_mode) {
+		SPDK_NOTICELOG("Enabling IDXD kernel with config #%u\n", req.config_number);
+	} else {
+		SPDK_NOTICELOG("Enabling IDXD with config #%u\n", req.config_number);
+	}
 
+	accel_engine_idxd_enable_probe(req.config_number, req.config_kernel_mode);
 	spdk_jsonrpc_send_bool_response(request, true);
 }
 SPDK_RPC_REGISTER("idxd_scan_accel_engine", rpc_idxd_scan_accel_engine, SPDK_RPC_STARTUP)

scripts/rpc.py

@@ -2373,12 +2373,15 @@ Format: 'user:u1 secret:s1 muser:mu1 msecret:ms1,user:u2 secret:s2 muser:mu2 mse
 
     # idxd
     def idxd_scan_accel_engine(args):
-        rpc.idxd.idxd_scan_accel_engine(args.client, config_number=args.config_number)
+        rpc.idxd.idxd_scan_accel_engine(args.client, config_number=args.config_number,
+                                        config_kernel_mode=args.config_kernel_mode)
 
     p = subparsers.add_parser('idxd_scan_accel_engine',
                               help='Set config and enable idxd accel engine offload.')
     p.add_argument('-c', '--config-number', help="""Pre-defined configuration number to use. See docs.""", type=int)
-    p.set_defaults(func=idxd_scan_accel_engine)
+    p.add_argument('-k', '--config-kernel-mode', help='Use Kernel mode idxd',
+                   action='store_true', dest='config_kernel_mode')
+    p.set_defaults(func=idxd_scan_accel_engine, config_kernel_mode=None)
 
     # opal
     def bdev_nvme_opal_init(args):

scripts/rpc/idxd.py

@@ -1,8 +1,13 @@
-def idxd_scan_accel_engine(client, config_number):
+def idxd_scan_accel_engine(client, config_number=None, config_kernel_mode=None):
     """Scan and enable IDXD accel engine.
 
     Args:
         config_number: Pre-defined configuration number, see docs.
+        config_kernel_mode: Use kernel IDXD driver. (optional)
     """
-    params = {'config_number': config_number}
+    params = {}
+
+    params['config_number'] = config_number
+    if config_kernel_mode is not None:
+        params['config_kernel_mode'] = config_kernel_mode
     return client.call('idxd_scan_accel_engine', params)

test/unit/lib/idxd/idxd.c/idxd_ut.c

@@ -54,7 +54,7 @@ test_spdk_idxd_set_config(void)
 {
 
 	g_dev_cfg = NULL;
-	spdk_idxd_set_config(0);
+	spdk_idxd_set_config(false, 0);
 	SPDK_CU_ASSERT_FATAL(g_dev_cfg != NULL);
 	CU_ASSERT(memcmp(&g_dev_cfg0, g_dev_cfg, sizeof(struct device_config)) == 0);