vlib: startup multi-arch variant configuration

Support for startup node multi-arch variant selection through startup.conf.
This is to facilitate unit, functional testing and benchmarking of non-default
multi-arch variant node code path. Also added parameters to make test, to
specific using multi-arch variants in unit testing.

Type: improvement

Signed-off-by: Ray Kinsella <mdr@ashroe.eu>
Change-Id: I94fd332bb629683b7a7dd770ee9f615a9a424060

5 files changed, 240 insertions, 1 deletions

diff --git a/src/vlib/CMakeLists.txt b/src/vlib/CMakeLists.txt
index 0085f64cc77..2846128ce93 100644
--- a/src/vlib/CMakeLists.txt
+++ b/src/vlib/CMakeLists.txt
@@ -69,6 +69,7 @@ add_vpp_library(vlib
   node.c
   node_cli.c
   node_format.c
+  node_init.c
   pci/pci.c
   pci/pci_types_api.c
   physmem.c
@@ -88,6 +89,7 @@ add_vpp_library(vlib
   MULTIARCH_SOURCES
   drop.c
   punt_node.c
+  node_init.c
 
   INSTALL_HEADERS
   buffer_funcs.h
diff --git a/src/vlib/node.h b/src/vlib/node.h
index 9f324f79fa4..b9961f55b56 100644
--- a/src/vlib/node.h
+++ b/src/vlib/node.h
@@ -218,6 +218,8 @@ CLIB_MARCH_SFX (node##_multiarch_register) (void)			\
 }									\
 uword CLIB_CPU_OPTIMIZED CLIB_MARCH_SFX (node##_fn)
 
+unformat_function_t unformat_vlib_node_variant;
+
 always_inline vlib_node_registration_t *
 vlib_node_next_registered (vlib_node_registration_t * c)
 {
diff --git a/src/vlib/node_cli.c b/src/vlib/node_cli.c
index 0738bc959ce..750f69e5d60 100644
--- a/src/vlib/node_cli.c
+++ b/src/vlib/node_cli.c
@@ -727,7 +727,7 @@ set_node_fn(vlib_main_t * vm, unformat_input_t * input, vlib_cli_command_t * cmd
       goto done;
     }
 
-  if (!unformat (line_input, "%s", &variant))
+  if (!unformat (line_input, "%U", unformat_vlib_node_variant, &variant))
     {
       err = clib_error_return (0, "please specify node functional variant");
       goto done;
diff --git a/src/vlib/node_init.c b/src/vlib/node_init.c
new file mode 100644
index 00000000000..47d288c6ef0
--- /dev/null
+++ b/src/vlib/node_init.c
@@ -0,0 +1,224 @@
+/*
+ * Copyright (c) 2020 Intel and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+/*
+ * node_init.c: node march variant startup initialization
+ *
+ * Copyright (c) 2020 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ *  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ *  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ *  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ *  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ *  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ *  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#include <sys/types.h>
+#include <fcntl.h>
+#include <vlib/vlib.h>
+
+typedef struct _vlib_node_march_variant
+{
+  struct _vlib_node_march_variant *next_variant;
+  char *name;
+} vlib_node_march_variant_t;
+
+#define VLIB_VARIANT_REGISTER()			\
+  static vlib_node_march_variant_t			\
+  CLIB_MARCH_VARIANT##variant;				\
+							\
+  static void __clib_constructor			\
+  CLIB_MARCH_VARIANT##_register (void)			\
+  {							\
+    extern vlib_node_march_variant_t *variants;	\
+    vlib_node_march_variant_t *v;			\
+    v = & CLIB_MARCH_VARIANT##variant;			\
+    v->name = CLIB_MARCH_VARIANT_STR;			\
+    v->next_variant = variants;			\
+    variants = v;					\
+  }							\
+
+VLIB_VARIANT_REGISTER ();
+
+#ifndef CLIB_MARCH_VARIANT
+
+vlib_node_march_variant_t *variants = 0;
+
+uword
+unformat_vlib_node_variant (unformat_input_t * input, va_list * args)
+{
+  u8 **variant = va_arg (*args, u8 **);
+  vlib_node_march_variant_t *v = variants;
+
+  if (!unformat (input, "%v", variant))
+    return 0;
+
+  while (v)
+    {
+      if (!strncmp (v->name, (char *) *variant, vec_len (*variant)))
+	return 1;
+
+      v = v->next_variant;
+    }
+
+  return 0;
+}
+
+static_always_inline void
+vlib_update_nr_variant_default (vlib_node_registration_t * nr, u8 * variant)
+{
+  vlib_node_fn_registration_t *fnr = nr->node_fn_registrations;
+  vlib_node_fn_registration_t *p_reg = 0;
+  vlib_node_fn_registration_t *v_reg = 0;
+  u32 tmp;
+
+  while (fnr)
+    {
+      /* which is the highest priority registration */
+      if (!p_reg || fnr->priority > p_reg->priority)
+	p_reg = fnr;
+
+      /* which is the variant we want to prioritize */
+      if (!strncmp (fnr->name, (char *) variant, vec_len (variant) - 1))
+	v_reg = fnr;
+
+      fnr = fnr->next_registration;
+    }
+
+  /* node doesn't have the variants */
+  if (!v_reg)
+    return;
+
+  ASSERT (p_reg != 0 && v_reg != 0);
+
+  /* swap priorities */
+  tmp = p_reg->priority;
+  p_reg->priority = v_reg->priority;
+  v_reg->priority = tmp;
+
+}
+
+static clib_error_t *
+vlib_early_node_config (vlib_main_t * vm, unformat_input_t * input)
+{
+  clib_error_t *error = 0;
+  vlib_node_registration_t *nr, **all;
+  unformat_input_t sub_input;
+  uword *hash = 0, *p;
+  u8 *variant = 0;
+  u8 *s = 0;
+
+  all = 0;
+  hash = hash_create_string (0, sizeof (uword));
+
+  nr = vm->node_main.node_registrations;
+  while (nr)
+    {
+      hash_set_mem (hash, nr->name, vec_len (all));
+      vec_add1 (all, nr);
+
+      nr = nr->next_registration;
+    }
+
+  /* specify prioritization defaults for all graph nodes */
+  while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
+    {
+      if (unformat (input, "default %U", unformat_vlib_cli_sub_input,
+		    &sub_input))
+	{
+	  while (unformat_check_input (&sub_input) != UNFORMAT_END_OF_INPUT)
+	    {
+	      if (!unformat (&sub_input, "variant %U",
+			     unformat_vlib_node_variant, &variant))
+		return clib_error_return (0,
+					  "please specify a valid node variant");
+	      vec_add1 (variant, 0);
+
+	      nr = vm->node_main.node_registrations;
+	      while (nr)
+		{
+		  vlib_update_nr_variant_default (nr, variant);
+		  nr = nr->next_registration;
+		}
+
+	      vec_free (variant);
+	    }
+	}
+      else /* specify prioritization for an individual graph node */
+      if (unformat (input, "%s", &s))
+	{
+	  if (!(p = hash_get_mem (hash, s)))
+	    {
+	      error = clib_error_return (0,
+					 "node variants: unknown graph node '%s'",
+					 s);
+	      break;
+	    }
+
+	  nr = vec_elt (all, p[0]);
+
+	  if (unformat (input, "%U", unformat_vlib_cli_sub_input, &sub_input))
+	    {
+	      while (unformat_check_input (&sub_input) !=
+		     UNFORMAT_END_OF_INPUT)
+		{
+		  if (!unformat (&sub_input, "variant %U",
+				 unformat_vlib_node_variant, &variant))
+		    return clib_error_return (0,
+					      "please specify a valid node variant");
+		  vec_add1 (variant, 0);
+
+		  vlib_update_nr_variant_default (nr, variant);
+
+		  vec_free (variant);
+		}
+	    }
+	}
+      else
+	{
+	  break;
+	}
+    }
+
+  hash_free (hash);
+  vec_free (all);
+  unformat_free (input);
+
+  return error;
+}
+
+VLIB_EARLY_CONFIG_FUNCTION (vlib_early_node_config, "node");
+
+#endif
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */
diff --git a/src/vpp/conf/startup.conf b/src/vpp/conf/startup.conf
index b0d0c86641f..86b73f7a77b 100644
--- a/src/vpp/conf/startup.conf
+++ b/src/vpp/conf/startup.conf
@@ -151,6 +151,17 @@ cpu {
 	# enable-tcp-udp-checksum
 # }
 
+## node variant defaults
+#node {
+
+## specify the preferred default variant
+#	default	{ variant avx512 }
+
+## specify the preferred variant, for a given node
+#	ip4-rewrite { variant avx2 }
+
+#}
+
 
 # plugins {
 	## Adjusting the plugin path depending on where the VPP plugins are