Add memif - packet memory interface for intra-host communication

Change-Id: I94c06b07a39f07ceba87bf3e7fcfc70e43231e8a
Signed-off-by: Damjan Marion <damarion@cisco.com>
Co-Authored-By: Milan Lenco <Milan.Lenco@pantheon.tech>

11 files changed, 2767 insertions, 0 deletions

diff --git a/src/plugins/Makefile.am b/src/plugins/Makefile.am
index 255e644f089..6713a9e25a3 100644
--- a/src/plugins/Makefile.am
+++ b/src/plugins/Makefile.am
@@ -57,6 +57,10 @@ if ENABLE_LB_PLUGIN
 include lb.am
 endif
 
+if ENABLE_MEMIF_PLUGIN
+include memif.am
+endif
+
 if ENABLE_SIXRD_PLUGIN
 include sixrd.am
 endif
diff --git a/src/plugins/memif.am b/src/plugins/memif.am
new file mode 100644
index 00000000000..d3a3171d039
--- /dev/null
+++ b/src/plugins/memif.am
@@ -0,0 +1,32 @@
+# Copyright (c) 2017 Cisco Systems, Inc.
+# 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.
+
+vppplugins_LTLIBRARIES += memif_plugin.la
+
+memif_plugin_la_SOURCES = memif/memif.c   \
+	memif/memif_api.c                 \
+	memif/cli.c                       \
+	memif/node.c                      \
+	memif/device.c                    \
+	memif/memif_plugin.api.h
+
+noinst_HEADERS += memif/memif.h
+
+nobase_apiinclude_HEADERS +=              \
+		  memif/memif_all_api_h.h \
+		  memif/memif_msg_enum.h  \
+		  memif/memif.api.h
+
+API_FILES += memif/memif.api
+
+# vi:syntax=automake
diff --git a/src/plugins/memif/cli.c b/src/plugins/memif/cli.c
new file mode 100644
index 00000000000..ef73693b35d
--- /dev/null
+++ b/src/plugins/memif/cli.c
@@ -0,0 +1,202 @@
+/*
+ *------------------------------------------------------------------
+ * Copyright (c) 2016 Cisco 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.
+ *------------------------------------------------------------------
+ */
+#include <stdint.h>
+#include <net/if.h>
+#include <sys/ioctl.h>
+#include <inttypes.h>
+
+#include <vlib/vlib.h>
+#include <vlib/unix/unix.h>
+#include <vnet/ethernet/ethernet.h>
+
+#include <memif/memif.h>
+
+static clib_error_t *
+memif_create_command_fn (vlib_main_t * vm, unformat_input_t * input,
+			 vlib_cli_command_t * cmd)
+{
+  unformat_input_t _line_input, *line_input = &_line_input;
+  int r;
+  u32 ring_size = MEMIF_DEFAULT_RING_SIZE;
+  memif_create_if_args_t args = { 0 };
+  args.buffer_size = MEMIF_DEFAULT_BUFFER_SIZE;
+
+  /* Get a line of input. */
+  if (!unformat_user (input, unformat_line_input, line_input))
+    return 0;
+
+  while (unformat_check_input (line_input) != UNFORMAT_END_OF_INPUT)
+    {
+      if (unformat (line_input, "key 0x%" PRIx64, &args.key))
+	;
+      else if (unformat (line_input, "socket %s", &args.socket_filename))
+	;
+      else if (unformat (line_input, "ring-size %u", &ring_size))
+	;
+      else if (unformat (line_input, "buffer-size %u", &args.buffer_size))
+	;
+      else if (unformat (line_input, "master"))
+	args.is_master = 1;
+      else if (unformat (line_input, "slave"))
+	args.is_master = 0;
+      else if (unformat (line_input, "hw-addr %U",
+			 unformat_ethernet_address, args.hw_addr))
+	args.hw_addr_set = 1;
+      else
+	return clib_error_return (0, "unknown input `%U'",
+				  format_unformat_error, input);
+    }
+  unformat_free (line_input);
+
+  if (!is_pow2 (ring_size))
+    return clib_error_return (0, "ring size must be power of 2");
+
+  args.log2_ring_size = min_log2 (ring_size);
+
+  r = memif_create_if (vm, &args);
+
+  if (r <= VNET_API_ERROR_SYSCALL_ERROR_1
+      && r >= VNET_API_ERROR_SYSCALL_ERROR_10)
+    return clib_error_return (0, "%s (errno %d)", strerror (errno), errno);
+
+  if (r == VNET_API_ERROR_INVALID_INTERFACE)
+    return clib_error_return (0, "Invalid interface name");
+
+  if (r == VNET_API_ERROR_SUBIF_ALREADY_EXISTS)
+    return clib_error_return (0, "Interface already exists");
+
+  return 0;
+}
+
+/* *INDENT-OFF* */
+VLIB_CLI_COMMAND (memif_create_command, static) = {
+  .path = "create memif",
+  .short_help = "create memif [key <key>] [socket <path>] "
+                "[ring-size <size>] [buffer-size <size>] [hw-addr <mac-address>] "
+		"<master|slave>",
+  .function = memif_create_command_fn,
+};
+/* *INDENT-ON* */
+
+static clib_error_t *
+memif_delete_command_fn (vlib_main_t * vm, unformat_input_t * input,
+			 vlib_cli_command_t * cmd)
+{
+  unformat_input_t _line_input, *line_input = &_line_input;
+  u64 key = 0;
+  u8 key_defined = 0;
+
+  /* Get a line of input. */
+  if (!unformat_user (input, unformat_line_input, line_input))
+    return 0;
+
+  while (unformat_check_input (line_input) != UNFORMAT_END_OF_INPUT)
+    {
+      if (unformat (line_input, "key 0x%" PRIx64, &key))
+	key_defined = 1;
+      else
+	return clib_error_return (0, "unknown input `%U'",
+				  format_unformat_error, input);
+    }
+  unformat_free (line_input);
+
+  if (!key_defined)
+    return clib_error_return (0, "missing key");
+
+  memif_delete_if (vm, key);
+
+  return 0;
+}
+
+/* *INDENT-OFF* */
+VLIB_CLI_COMMAND (memif_delete_command, static) = {
+  .path = "delete memif",
+  .short_help = "delete memif key <key-value>",
+  .function = memif_delete_command_fn,
+};
+/* *INDENT-ON* */
+
+static clib_error_t *
+memif_show_command_fn (vlib_main_t * vm, unformat_input_t * input,
+		       vlib_cli_command_t * cmd)
+{
+  memif_main_t *mm = &memif_main;
+  memif_if_t *mif;
+  vnet_main_t *vnm = vnet_get_main ();
+  int i;
+
+  /* *INDENT-OFF* */
+  pool_foreach (mif, mm->interfaces,
+    ({
+       vlib_cli_output (vm, "interface %U", format_vnet_sw_if_index_name,
+			vnm, mif->sw_if_index);
+       vlib_cli_output (vm, "  key 0x%" PRIx64 " file %s", mif->key,
+			mif->socket_filename);
+       vlib_cli_output (vm, "  listener %d conn-fd %d int-fd %d", mif->listener_index,
+			mif->connection.fd, mif->interrupt_line.fd);
+       vlib_cli_output (vm, "  ring-size %u num-c2s-rings %u num-s2c-rings %u buffer_size %u",
+			(1 << mif->log2_ring_size),
+			mif->num_s2m_rings,
+			mif->num_m2s_rings,
+			mif->buffer_size);
+       for (i=0; i < mif->num_s2m_rings; i++)
+         {
+	   memif_ring_t * ring = memif_get_ring (mif, MEMIF_RING_S2M, i);
+	   if (ring)
+	     {
+	       vlib_cli_output (vm, "  slave-to-master ring %u:", i);
+	       vlib_cli_output (vm, "    head %u tail %u", ring->head, ring->tail);
+	     }
+	 }
+       for (i=0; i < mif->num_m2s_rings; i++)
+         {
+	   memif_ring_t * ring = memif_get_ring (mif, MEMIF_RING_M2S, i);
+	   if (ring)
+	     {
+	       vlib_cli_output (vm, "  master-to-slave ring %u:", i);
+	       vlib_cli_output (vm, "    head %u tail %u", ring->head, ring->tail);
+	     }
+	 }
+    }));
+  /* *INDENT-ON* */
+
+  return 0;
+}
+
+/* *INDENT-OFF* */
+VLIB_CLI_COMMAND (memif_show_command, static) = {
+  .path = "show memif",
+  .short_help = "show memif",
+  .function = memif_show_command_fn,
+};
+/* *INDENT-ON* */
+
+clib_error_t *
+memif_cli_init (vlib_main_t * vm)
+{
+  return 0;
+}
+
+VLIB_INIT_FUNCTION (memif_cli_init);
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */
diff --git a/src/plugins/memif/device.c b/src/plugins/memif/device.c
new file mode 100644
index 00000000000..446537a3792
--- /dev/null
+++ b/src/plugins/memif/device.c
@@ -0,0 +1,330 @@
+/*
+ *------------------------------------------------------------------
+ * Copyright (c) 2016 Cisco 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.
+ *------------------------------------------------------------------
+ */
+
+#define _GNU_SOURCE
+#include <stdint.h>
+#include <net/if.h>
+#include <sys/ioctl.h>
+#include <sys/uio.h>
+
+#include <vlib/vlib.h>
+#include <vlib/unix/unix.h>
+#include <vnet/ethernet/ethernet.h>
+
+#include <memif/memif.h>
+
+#define foreach_memif_tx_func_error	       \
+_(NO_FREE_SLOTS, "no free tx slots")           \
+_(PENDING_MSGS, "pending msgs in tx ring")
+
+typedef enum
+{
+#define _(f,s) MEMIF_TX_ERROR_##f,
+  foreach_memif_tx_func_error
+#undef _
+    MEMIF_TX_N_ERROR,
+} memif_tx_func_error_t;
+
+static char *memif_tx_func_error_strings[] = {
+#define _(n,s) s,
+  foreach_memif_tx_func_error
+#undef _
+};
+
+
+static u8 *
+format_memif_device_name (u8 * s, va_list * args)
+{
+  u32 i = va_arg (*args, u32);
+
+  s = format (s, "memif%u", i);
+  return s;
+}
+
+static u8 *
+format_memif_device (u8 * s, va_list * args)
+{
+  u32 dev_instance = va_arg (*args, u32);
+  int verbose = va_arg (*args, int);
+  uword indent = format_get_indent (s);
+
+  s = format (s, "MEMIF interface");
+  if (verbose)
+    {
+      s = format (s, "\n%U instance %u", format_white_space, indent + 2,
+		  dev_instance);
+    }
+  return s;
+}
+
+static u8 *
+format_memif_tx_trace (u8 * s, va_list * args)
+{
+  s = format (s, "Unimplemented...");
+  return s;
+}
+
+static_always_inline void
+memif_interface_lock (memif_if_t * mif)
+{
+  if (PREDICT_FALSE (mif->lockp != 0))
+    {
+      while (__sync_lock_test_and_set (mif->lockp, 1))
+	;
+    }
+}
+
+static_always_inline void
+memif_interface_unlock (memif_if_t * mif)
+{
+  if (PREDICT_FALSE (mif->lockp != 0))
+    *mif->lockp = 0;
+}
+
+static_always_inline void
+memif_prefetch_buffer_and_data (vlib_main_t * vm, u32 bi)
+{
+  vlib_buffer_t *b = vlib_get_buffer (vm, bi);
+  vlib_prefetch_buffer_header (b, LOAD);
+  CLIB_PREFETCH (b->data, CLIB_CACHE_LINE_BYTES, LOAD);
+}
+
+static_always_inline uword
+memif_interface_tx_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
+			   vlib_frame_t * frame, memif_if_t * mif,
+			   memif_ring_type_t type)
+{
+  u8 rid = 0;
+  memif_ring_t *ring = memif_get_ring (mif, type, rid);
+  u32 *buffers = vlib_frame_args (frame);
+  u32 n_left = frame->n_vectors;
+  u16 ring_size = 1 << mif->log2_ring_size;
+  u16 mask = ring_size - 1;
+  u16 head, tail;
+  u16 free_slots;
+
+  memif_interface_lock (mif);
+
+  /* free consumed buffers */
+
+  head = ring->head;
+  tail = ring->tail;
+
+  if (tail > head)
+    free_slots = tail - head;
+  else
+    free_slots = ring_size - head + tail;
+
+  while (n_left > 5 && free_slots > 1)
+    {
+      if (PREDICT_TRUE (head + 5 < ring_size))
+	{
+	  CLIB_PREFETCH (memif_get_buffer (mif, ring, head + 2),
+			 CLIB_CACHE_LINE_BYTES, STORE);
+	  CLIB_PREFETCH (memif_get_buffer (mif, ring, head + 3),
+			 CLIB_CACHE_LINE_BYTES, STORE);
+	  CLIB_PREFETCH (&ring->desc[head + 4], CLIB_CACHE_LINE_BYTES, STORE);
+	  CLIB_PREFETCH (&ring->desc[head + 5], CLIB_CACHE_LINE_BYTES, STORE);
+	}
+      else
+	{
+	  CLIB_PREFETCH (memif_get_buffer (mif, ring, (head + 2) % mask),
+			 CLIB_CACHE_LINE_BYTES, STORE);
+	  CLIB_PREFETCH (memif_get_buffer (mif, ring, (head + 3) % mask),
+			 CLIB_CACHE_LINE_BYTES, STORE);
+	  CLIB_PREFETCH (&ring->desc[(head + 4) % mask],
+			 CLIB_CACHE_LINE_BYTES, STORE);
+	  CLIB_PREFETCH (&ring->desc[(head + 5) % mask],
+			 CLIB_CACHE_LINE_BYTES, STORE);
+	}
+
+      memif_prefetch_buffer_and_data (vm, buffers[2]);
+      memif_prefetch_buffer_and_data (vm, buffers[3]);
+
+      vlib_buffer_t *b0 = vlib_get_buffer (vm, buffers[0]);
+      vlib_buffer_t *b1 = vlib_get_buffer (vm, buffers[1]);
+
+      void *mb0 = memif_get_buffer (mif, ring, head);
+      clib_memcpy (mb0, vlib_buffer_get_current (b0), CLIB_CACHE_LINE_BYTES);
+      ring->desc[head].length = b0->current_length;
+      head = (head + 1) & mask;
+
+      void *mb1 = memif_get_buffer (mif, ring, head);
+      clib_memcpy (mb1, vlib_buffer_get_current (b1), CLIB_CACHE_LINE_BYTES);
+      ring->desc[head].length = b1->current_length;
+      head = (head + 1) & mask;
+
+      if (b0->current_length > CLIB_CACHE_LINE_BYTES)
+	{
+	  clib_memcpy (mb0 + CLIB_CACHE_LINE_BYTES,
+		       vlib_buffer_get_current (b0) + CLIB_CACHE_LINE_BYTES,
+		       b0->current_length - CLIB_CACHE_LINE_BYTES);
+	}
+      if (b1->current_length > CLIB_CACHE_LINE_BYTES)
+	{
+	  clib_memcpy (mb1 + CLIB_CACHE_LINE_BYTES,
+		       vlib_buffer_get_current (b1) + CLIB_CACHE_LINE_BYTES,
+		       b1->current_length - CLIB_CACHE_LINE_BYTES);
+	}
+
+
+      buffers += 2;
+      n_left -= 2;
+      free_slots -= 2;
+    }
+
+  while (n_left && free_slots)
+    {
+      vlib_buffer_t *b0 = vlib_get_buffer (vm, buffers[0]);
+      void *mb0 = memif_get_buffer (mif, ring, head);
+      clib_memcpy (mb0, vlib_buffer_get_current (b0), CLIB_CACHE_LINE_BYTES);
+
+      if (b0->current_length > CLIB_CACHE_LINE_BYTES)
+	{
+	  clib_memcpy (mb0 + CLIB_CACHE_LINE_BYTES,
+		       vlib_buffer_get_current (b0) + CLIB_CACHE_LINE_BYTES,
+		       b0->current_length - CLIB_CACHE_LINE_BYTES);
+	}
+      ring->desc[head].length = b0->current_length;
+      head = (head + 1) & mask;
+
+      buffers++;
+      n_left--;
+      free_slots--;
+    }
+
+  CLIB_MEMORY_STORE_BARRIER ();
+  ring->head = head;
+
+  memif_interface_unlock (mif);
+
+  if (n_left)
+    {
+      vlib_error_count (vm, node->node_index, MEMIF_TX_ERROR_NO_FREE_SLOTS,
+			n_left);
+      vlib_buffer_free (vm, buffers, n_left);
+    }
+
+  vlib_buffer_free (vm, vlib_frame_args (frame), frame->n_vectors);
+  if (mif->interrupt_line.fd > 0)
+    {
+      u8 b = rid;
+      CLIB_UNUSED (int r) = write (mif->interrupt_line.fd, &b, sizeof (b));
+    }
+
+  return frame->n_vectors;
+}
+
+static uword
+memif_interface_tx (vlib_main_t * vm,
+		    vlib_node_runtime_t * node, vlib_frame_t * frame)
+{
+  memif_main_t *nm = &memif_main;
+  vnet_interface_output_runtime_t *rund = (void *) node->runtime_data;
+  memif_if_t *mif = pool_elt_at_index (nm->interfaces, rund->dev_instance);
+
+  if (mif->flags & MEMIF_IF_FLAG_IS_SLAVE)
+    return memif_interface_tx_inline (vm, node, frame, mif, MEMIF_RING_S2M);
+  else
+    return memif_interface_tx_inline (vm, node, frame, mif, MEMIF_RING_M2S);
+}
+
+static void
+memif_set_interface_next_node (vnet_main_t * vnm, u32 hw_if_index,
+			       u32 node_index)
+{
+  memif_main_t *apm = &memif_main;
+  vnet_hw_interface_t *hw = vnet_get_hw_interface (vnm, hw_if_index);
+  memif_if_t *mif = pool_elt_at_index (apm->interfaces, hw->dev_instance);
+
+  /* Shut off redirection */
+  if (node_index == ~0)
+    {
+      mif->per_interface_next_index = node_index;
+      return;
+    }
+
+  mif->per_interface_next_index =
+    vlib_node_add_next (vlib_get_main (), memif_input_node.index, node_index);
+}
+
+static void
+memif_clear_hw_interface_counters (u32 instance)
+{
+  /* Nothing for now */
+}
+
+static clib_error_t *
+memif_interface_admin_up_down (vnet_main_t * vnm, u32 hw_if_index, u32 flags)
+{
+  memif_main_t *apm = &memif_main;
+  memif_msg_t msg;
+  vnet_hw_interface_t *hw = vnet_get_hw_interface (vnm, hw_if_index);
+  memif_if_t *mif = pool_elt_at_index (apm->interfaces, hw->dev_instance);
+
+  if (flags & VNET_SW_INTERFACE_FLAG_ADMIN_UP)
+    mif->flags |= MEMIF_IF_FLAG_ADMIN_UP;
+  else
+    {
+      mif->flags &= ~MEMIF_IF_FLAG_ADMIN_UP;
+      if (!(mif->flags & MEMIF_IF_FLAG_DELETING)
+	  && mif->connection.index != ~0)
+	{
+	  msg.version = MEMIF_VERSION;
+	  msg.type = MEMIF_MSG_TYPE_DISCONNECT;
+	  send (mif->connection.fd, &msg, sizeof (msg), 0);
+	}
+    }
+
+  return 0;
+}
+
+static clib_error_t *
+memif_subif_add_del_function (vnet_main_t * vnm,
+			      u32 hw_if_index,
+			      struct vnet_sw_interface_t *st, int is_add)
+{
+  /* Nothing for now */
+  return 0;
+}
+
+/* *INDENT-OFF* */
+VNET_DEVICE_CLASS (memif_device_class) = {
+  .name = "memif",
+  .tx_function = memif_interface_tx,
+  .format_device_name = format_memif_device_name,
+  .format_device = format_memif_device,
+  .format_tx_trace = format_memif_tx_trace,
+  .tx_function_n_errors = MEMIF_TX_N_ERROR,
+  .tx_function_error_strings = memif_tx_func_error_strings,
+  .rx_redirect_to_node = memif_set_interface_next_node,
+  .clear_counters = memif_clear_hw_interface_counters,
+  .admin_up_down_function = memif_interface_admin_up_down,
+  .subif_add_del_function = memif_subif_add_del_function,
+};
+
+VLIB_DEVICE_TX_FUNCTION_MULTIARCH(memif_device_class,
+				  memif_interface_tx)
+/* *INDENT-ON* */
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */
diff --git a/src/plugins/memif/memif.api b/src/plugins/memif/memif.api
new file mode 100644
index 00000000000..6f946421411
--- /dev/null
+++ b/src/plugins/memif/memif.api
@@ -0,0 +1,127 @@
+/*
+ * Copyright (c) 2017 Cisco 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.
+ */
+
+/** \brief Create memory interface
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+    @param role - role of the interface in the connection (master/slave)
+    @param key - 64bit integer used to authenticate and match opposite sides
+           of the connection
+    @param socket_filename - filename of the socket to be used for connection
+           establishment
+    @param ring_size - the number of entries of RX/TX rings
+    @param buffer_size - size of the buffer allocated for each ring entry
+    @param hw_addr - interface MAC address
+*/
+define memif_create
+{
+  u32 client_index;
+  u32 context;
+
+  u8 role; /* 0 = master, 1 = slave */
+  u64 key; /* optional, default is 0 */
+  u8 socket_filename[128]; /* optional, default is "/var/vpp/memif.sock"
+                              and can be changed in VPP startup config */
+
+  u32 ring_size; /* optional, default is 1024 entries, must be power of 2 */
+  u16 buffer_size; /* optional, default is 2048 bytes */
+  u8 hw_addr[6]; /* optional, randomly generated if not defined */
+};
+
+/** \brief Create memory interface response
+    @param context - sender context, to match reply w/ request
+    @param retval - return value for request
+    @param sw_if_index - software index of the newly created interface
+*/
+define memif_create_reply
+{
+  u32 context;
+  i32 retval;
+  u32 sw_if_index;
+};
+
+/** \brief Delete memory interface
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+    @param sw_if_index - software index of the interface to delete
+*/
+define memif_delete
+{
+  u32 client_index;
+  u32 context;
+
+  u32 sw_if_index;
+};
+
+/** \brief Delete host-interface response
+    @param context - sender context, to match reply w/ request
+    @param retval - return value for request
+*/
+define memif_delete_reply
+{
+  u32 context;
+  i32 retval;
+};
+
+/** \brief Memory interface details structure
+    @param context - sender context, to match reply w/ request (memif_dump)
+    @param sw_if_index - index of the interface
+    @param if_name - name of the interface
+    @param hw_addr - interface MAC address
+    @param key - key associated with the interface
+    @param role - role of the interface in the connection (master/slave)
+    @param socket_filename - name of the socket used by this interface
+           to establish new connections
+    @param ring_size - the number of entries of RX/TX rings
+    @param buffer_size - size of the buffer allocated for each ring entry
+    @param admin_up_down - interface administrative status
+    @param link_up_down - interface link status
+
+*/
+define memif_details
+{
+  u32 context;
+
+  u32 sw_if_index;
+  u8 if_name[64];
+  u8 hw_addr[6];
+
+  /* memif specific parameters */
+  u64 key;
+  u8 role; /* 0 = master, 1 = slave */
+  u8 socket_filename[128];
+  u32 ring_size;
+  u16 buffer_size; /* optional, default is 2048 bytes */
+
+  /* 1 = up, 0 = down */
+  u8 admin_up_down;
+  u8 link_up_down;
+};
+
+/** \brief Dump all memory interfaces
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+*/
+define memif_dump
+{
+  u32 client_index;
+  u32 context;
+};
+
+/*
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */
diff --git a/src/plugins/memif/memif.c b/src/plugins/memif/memif.c
new file mode 100644
index 00000000000..7ba67c5b898
--- /dev/null
+++ b/src/plugins/memif/memif.c
@@ -0,0 +1,1045 @@
+/*
+ *------------------------------------------------------------------
+ * Copyright (c) 2016 Cisco 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.
+ *------------------------------------------------------------------
+ */
+
+#define _GNU_SOURCE
+#include <stdint.h>
+#include <net/if.h>
+#include <sys/types.h>
+#include <fcntl.h>
+#include <sys/ioctl.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <sys/uio.h>
+#include <sys/mman.h>
+#include <sys/prctl.h>
+#include <inttypes.h>
+
+#include <vlib/vlib.h>
+#include <vlib/unix/unix.h>
+#include <vnet/plugin/plugin.h>
+#include <vnet/ethernet/ethernet.h>
+#include <vpp/app/version.h>
+#include <memif/memif.h>
+
+#define MEMIF_DEBUG 1
+
+#if MEMIF_DEBUG == 1
+#define DEBUG_LOG(...) clib_warning(__VA_ARGS__)
+#define DEBUG_UNIX_LOG(...) clib_unix_warning(__VA_ARGS__)
+#else
+#define DEBUG_LOG(...)
+#endif
+
+memif_main_t memif_main;
+
+static clib_error_t *memif_conn_fd_read_ready (unix_file_t * uf);
+static clib_error_t *memif_int_fd_read_ready (unix_file_t * uf);
+
+static u32
+memif_eth_flag_change (vnet_main_t * vnm, vnet_hw_interface_t * hi, u32 flags)
+{
+  /* nothing for now */
+  return 0;
+}
+
+static void
+memif_remove_pending_conn (memif_pending_conn_t * pending_conn)
+{
+  memif_main_t *mm = &memif_main;
+
+  unix_file_del (&unix_main,
+		 unix_main.file_pool + pending_conn->connection.index);
+  pool_put (mm->pending_conns, pending_conn);
+}
+
+static void
+memif_connect (vlib_main_t * vm, memif_if_t * mif)
+{
+  vnet_main_t *vnm = vnet_get_main ();
+  int num_rings = mif->num_s2m_rings + mif->num_m2s_rings;
+  memif_ring_data_t *rd = NULL;
+
+  vec_validate_aligned (mif->ring_data, num_rings - 1, CLIB_CACHE_LINE_BYTES);
+  vec_foreach (rd, mif->ring_data)
+  {
+    rd->last_head = 0;
+  }
+
+  mif->flags &= ~MEMIF_IF_FLAG_CONNECTING;
+  mif->flags |= MEMIF_IF_FLAG_CONNECTED;
+  vnet_hw_interface_set_flags (vnm, mif->hw_if_index,
+			       VNET_HW_INTERFACE_FLAG_LINK_UP);
+}
+
+static void
+memif_disconnect (vlib_main_t * vm, memif_if_t * mif)
+{
+  vnet_main_t *vnm = vnet_get_main ();
+
+  mif->flags &= ~(MEMIF_IF_FLAG_CONNECTED | MEMIF_IF_FLAG_CONNECTING);
+  if (mif->hw_if_index != ~0)
+    vnet_hw_interface_set_flags (vnm, mif->hw_if_index, 0);
+
+  if (mif->interrupt_line.index != ~0)
+    {
+      unix_file_del (&unix_main,
+		     unix_main.file_pool + mif->interrupt_line.index);
+      mif->interrupt_line.index = ~0;
+      mif->interrupt_line.fd = -1;	/* closed in unix_file_del */
+    }
+  if (mif->connection.index != ~0)
+    {
+      unix_file_del (&unix_main, unix_main.file_pool + mif->connection.index);
+      mif->connection.index = ~0;
+      mif->connection.fd = -1;	/* closed in unix_file_del */
+    }
+
+  // TODO: properly munmap + close memif-owned shared memory segments
+  vec_free (mif->regions);
+}
+
+static clib_error_t *
+memif_process_connect_req (memif_pending_conn_t * pending_conn,
+			   memif_msg_t * req, struct ucred *slave_cr,
+			   int shm_fd, int int_fd)
+{
+  memif_main_t *mm = &memif_main;
+  vlib_main_t *vm = vlib_get_main ();
+  int fd = pending_conn->connection.fd;
+  unix_file_t *uf = 0;
+  memif_if_t *mif = 0;
+  memif_msg_t resp = { 0 };
+  unix_file_t template = { 0 };
+  void *shm;
+  uword *p;
+  u8 retval = 0;
+  static clib_error_t *error = 0;
+
+  if (shm_fd == -1)
+    {
+      DEBUG_LOG
+	("Connection request is missing shared memory file descriptor");
+      retval = 1;
+      goto response;
+    }
+
+  if (int_fd == -1)
+    {
+      DEBUG_LOG
+	("Connection request is missing interrupt line file descriptor");
+      retval = 2;
+      goto response;
+    }
+
+  if (slave_cr == NULL)
+    {
+      DEBUG_LOG ("Connection request is missing slave credentials");
+      retval = 3;
+      goto response;
+    }
+
+  p = mhash_get (&mm->if_index_by_key, &req->key);
+  if (!p)
+    {
+      DEBUG_LOG
+	("Connection request with unmatched key (0x%" PRIx64 ")", req->key);
+      retval = 4;
+      goto response;
+    }
+
+  mif = vec_elt_at_index (mm->interfaces, *p);
+  if (mif->listener_index != pending_conn->listener_index)
+    {
+      DEBUG_LOG
+	("Connection request with non-matching listener (%d vs. %d)",
+	 pending_conn->listener_index, mif->listener_index);
+      retval = 5;
+      goto response;
+    }
+
+  if (mif->flags & MEMIF_IF_FLAG_IS_SLAVE)
+    {
+      DEBUG_LOG ("Memif slave does not accept connection requests");
+      retval = 6;
+      goto response;
+    }
+
+  if (mif->connection.fd != -1)
+    {
+      DEBUG_LOG
+	("Memif with key 0x%" PRIx64 " is already connected", mif->key);
+      retval = 7;
+      goto response;
+    }
+
+  if ((mif->flags & MEMIF_IF_FLAG_ADMIN_UP) == 0)
+    {
+      /* just silently decline the request */
+      retval = 8;
+      goto response;
+    }
+
+  if (req->shared_mem_size < sizeof (memif_shm_t))
+    {
+      DEBUG_LOG
+	("Unexpectedly small shared memory segment received from slave.");
+      retval = 9;
+      goto response;
+    }
+
+  if ((shm =
+       mmap (NULL, req->shared_mem_size, PROT_READ | PROT_WRITE, MAP_SHARED,
+	     shm_fd, 0)) == MAP_FAILED)
+    {
+      DEBUG_UNIX_LOG
+	("Failed to map shared memory segment received from slave memif");
+      error = clib_error_return_unix (0, "mmap fd %d", shm_fd);
+      retval = 10;
+      goto response;
+    }
+
+  if (((memif_shm_t *) shm)->cookie != 0xdeadbeef)
+    {
+      DEBUG_LOG
+	("Possibly corrupted shared memory segment received from slave memif");
+      munmap (shm, req->shared_mem_size);
+      retval = 11;
+      goto response;
+    }
+
+  mif->log2_ring_size = req->log2_ring_size;
+  mif->num_s2m_rings = req->num_s2m_rings;
+  mif->num_m2s_rings = req->num_m2s_rings;
+  mif->buffer_size = req->buffer_size;
+  mif->remote_pid = slave_cr->pid;
+  mif->remote_uid = slave_cr->uid;
+  vec_add1 (mif->regions, shm);
+
+  /* register interrupt line */
+  mif->interrupt_line.fd = int_fd;
+  template.read_function = memif_int_fd_read_ready;
+  template.file_descriptor = int_fd;
+  template.private_data = mif->if_index;
+  mif->interrupt_line.index = unix_file_add (&unix_main, &template);
+
+  /* change context for future messages */
+  uf = vec_elt_at_index (unix_main.file_pool, pending_conn->connection.index);
+  uf->private_data = mif->if_index << 1;
+  mif->connection = pending_conn->connection;
+  pool_put (mm->pending_conns, pending_conn);
+
+  memif_connect (vm, mif);
+
+response:
+  resp.version = MEMIF_VERSION;
+  resp.type = MEMIF_MSG_TYPE_CONNECT_RESP;
+  resp.retval = retval;
+  send (fd, &resp, sizeof (resp), 0);
+  return error;
+}
+
+static clib_error_t *
+memif_process_connect_resp (memif_if_t * mif, memif_msg_t * resp)
+{
+  vlib_main_t *vm = vlib_get_main ();
+
+  if ((mif->flags & MEMIF_IF_FLAG_IS_SLAVE) == 0)
+    {
+      DEBUG_LOG ("Memif master does not accept connection responses");
+      return 0;
+    }
+
+  if ((mif->flags & MEMIF_IF_FLAG_CONNECTING) == 0)
+    {
+      DEBUG_LOG ("Unexpected connection response");
+      return 0;
+    }
+
+  if (resp->retval == 0)
+    memif_connect (vm, mif);
+  else
+    memif_disconnect (vm, mif);
+
+  return 0;
+}
+
+static clib_error_t *
+memif_conn_fd_read_ready (unix_file_t * uf)
+{
+  memif_main_t *mm = &memif_main;
+  vlib_main_t *vm = vlib_get_main ();
+  memif_if_t *mif = 0;
+  memif_pending_conn_t *pending_conn = 0;
+  int fd_array[2] = { -1, -1 };
+  char ctl[CMSG_SPACE (sizeof (fd_array)) +
+	   CMSG_SPACE (sizeof (struct ucred))] = { 0 };
+  struct msghdr mh = { 0 };
+  struct iovec iov[1];
+  struct ucred *cr = 0;
+  memif_msg_t msg = { 0 };
+  struct cmsghdr *cmsg;
+  ssize_t size;
+  static clib_error_t *error = 0;
+
+  iov[0].iov_base = (void *) &msg;
+  iov[0].iov_len = sizeof (memif_msg_t);
+  mh.msg_iov = iov;
+  mh.msg_iovlen = 1;
+  mh.msg_control = ctl;
+  mh.msg_controllen = sizeof (ctl);
+
+  /* grab the appropriate context */
+  if (uf->private_data & 1)
+    pending_conn = vec_elt_at_index (mm->pending_conns,
+				     uf->private_data >> 1);
+  else
+    mif = vec_elt_at_index (mm->interfaces, uf->private_data >> 1);
+
+  /* receive the incoming message */
+  size = recvmsg (uf->file_descriptor, &mh, 0);
+  if (size != sizeof (memif_msg_t))
+    {
+      if (size != 0)
+	{
+	  DEBUG_UNIX_LOG ("Malformed message received on fd %d",
+			  uf->file_descriptor);
+	  error = clib_error_return_unix (0, "recvmsg fd %d",
+					  uf->file_descriptor);
+	}
+      goto disconnect;
+    }
+
+  /* check version of the sender's memif plugin */
+  if (msg.version != MEMIF_VERSION)
+    {
+      DEBUG_LOG ("Memif version mismatch");
+      goto disconnect;
+    }
+
+  /* process the message based on its type */
+  switch (msg.type)
+    {
+    case MEMIF_MSG_TYPE_CONNECT_REQ:
+      if (pending_conn == 0)
+	{
+	  DEBUG_LOG ("Received unexpected connection request");
+	  return 0;
+	}
+
+      /* Read anciliary data */
+      cmsg = CMSG_FIRSTHDR (&mh);
+      while (cmsg)
+	{
+	  if (cmsg->cmsg_level == SOL_SOCKET
+	      && cmsg->cmsg_type == SCM_CREDENTIALS)
+	    {
+	      cr = (struct ucred *) CMSG_DATA (cmsg);
+	    }
+	  else if (cmsg->cmsg_level == SOL_SOCKET
+		   && cmsg->cmsg_type == SCM_RIGHTS)
+	    {
+	      clib_memcpy (fd_array, CMSG_DATA (cmsg), sizeof (fd_array));
+	    }
+	  cmsg = CMSG_NXTHDR (&mh, cmsg);
+	}
+
+      return memif_process_connect_req (pending_conn, &msg, cr,
+					fd_array[0], fd_array[1]);
+
+    case MEMIF_MSG_TYPE_CONNECT_RESP:
+      if (mif == 0)
+	{
+	  DEBUG_LOG ("Received unexpected connection response");
+	  return 0;
+	}
+      return memif_process_connect_resp (mif, &msg);
+
+    case MEMIF_MSG_TYPE_DISCONNECT:
+      goto disconnect;
+
+    default:
+      DEBUG_LOG ("Received unknown message type");
+      goto disconnect;
+    }
+
+  return 0;
+
+disconnect:
+  if (pending_conn)
+    memif_remove_pending_conn (pending_conn);
+  else
+    memif_disconnect (vm, mif);
+  return error;
+}
+
+static clib_error_t *
+memif_int_fd_read_ready (unix_file_t * uf)
+{
+  memif_main_t *mm = &memif_main;
+  vlib_main_t *vm = vlib_get_main ();
+  memif_if_t *mif = vec_elt_at_index (mm->interfaces, uf->private_data);
+  u8 b;
+  ssize_t size;
+
+  size = read (uf->file_descriptor, &b, sizeof (b));
+  if (0 == size)
+    {
+      /* interrupt line was disconnected */
+      unix_file_del (&unix_main,
+		     unix_main.file_pool + mif->interrupt_line.index);
+      mif->interrupt_line.index = ~0;
+      mif->interrupt_line.fd = -1;
+    }
+  vlib_node_set_interrupt_pending (vm, memif_input_node.index);
+  return 0;
+}
+
+static clib_error_t *
+memif_conn_fd_accept_ready (unix_file_t * uf)
+{
+  memif_main_t *mm = &memif_main;
+  memif_listener_t *listener = 0;
+  memif_pending_conn_t *pending_conn = 0;
+  int addr_len;
+  struct sockaddr_un client;
+  int conn_fd;
+  unix_file_t template = { 0 };
+
+  listener = pool_elt_at_index (mm->listeners, uf->private_data);
+
+  addr_len = sizeof (client);
+  conn_fd = accept (uf->file_descriptor,
+		    (struct sockaddr *) &client, (socklen_t *) & addr_len);
+
+  if (conn_fd < 0)
+    return clib_error_return_unix (0, "accept fd %d", uf->file_descriptor);
+
+  pool_get (mm->pending_conns, pending_conn);
+  pending_conn->index = pending_conn - mm->pending_conns;
+  pending_conn->listener_index = listener->index;
+  pending_conn->connection.fd = conn_fd;
+
+  template.read_function = memif_conn_fd_read_ready;
+  template.file_descriptor = conn_fd;
+  template.private_data = (pending_conn->index << 1) | 1;
+  pending_conn->connection.index = unix_file_add (&unix_main, &template);
+
+  return 0;
+}
+
+static void
+memif_connect_master (vlib_main_t * vm, memif_if_t * mif)
+{
+  memif_msg_t msg;
+  struct msghdr mh = { 0 };
+  struct iovec iov[1];
+  struct cmsghdr *cmsg;
+  int mfd = -1;
+  int rv;
+  int fd_array[2] = { -1, -1 };
+  char ctl[CMSG_SPACE (sizeof (fd_array))];
+  memif_ring_t *ring = NULL;
+  int i, j;
+  void *shm = 0;
+  u64 buffer_offset;
+  unix_file_t template = { 0 };
+
+  msg.version = MEMIF_VERSION;
+  msg.type = MEMIF_MSG_TYPE_CONNECT_REQ;
+  msg.key = mif->key;
+  msg.log2_ring_size = mif->log2_ring_size;
+  msg.num_s2m_rings = mif->num_s2m_rings;
+  msg.num_m2s_rings = mif->num_m2s_rings;
+  msg.buffer_size = mif->buffer_size;
+
+  buffer_offset = sizeof (memif_shm_t) +
+    (mif->num_s2m_rings + mif->num_m2s_rings) *
+    (sizeof (memif_ring_t) +
+     sizeof (memif_desc_t) * (1 << mif->log2_ring_size));
+
+  msg.shared_mem_size = buffer_offset +
+    mif->buffer_size * (1 << mif->log2_ring_size) * (mif->num_s2m_rings +
+						     mif->num_m2s_rings);
+
+  if ((mfd = memfd_create ("shared mem", MFD_ALLOW_SEALING)) == -1)
+    {
+      DEBUG_LOG ("Failed to create anonymous file");
+      goto error;
+    }
+
+  if ((fcntl (mfd, F_ADD_SEALS, F_SEAL_SHRINK)) == -1)
+    {
+      DEBUG_UNIX_LOG ("Failed to seal an anonymous file off from truncating");
+      goto error;
+    }
+
+  if ((ftruncate (mfd, msg.shared_mem_size)) == -1)
+    {
+      DEBUG_UNIX_LOG ("Failed to extend the size of an anonymous file");
+      goto error;
+    }
+
+  if ((shm = mmap (NULL, msg.shared_mem_size, PROT_READ | PROT_WRITE,
+		   MAP_SHARED, mfd, 0)) == MAP_FAILED)
+    {
+      DEBUG_UNIX_LOG ("Failed to map anonymous file into memory");
+      goto error;
+    }
+
+  vec_add1 (mif->regions, shm);
+  ((memif_shm_t *) mif->regions[0])->cookie = 0xdeadbeef;
+
+  for (i = 0; i < mif->num_s2m_rings; i++)
+    {
+      ring = memif_get_ring (mif, MEMIF_RING_S2M, i);
+      ring->head = ring->tail = 0;
+      for (j = 0; j < (1 << mif->log2_ring_size); j++)
+	{
+	  u16 slot = i * (1 << mif->log2_ring_size) + j;
+	  ring->desc[j].region = 0;
+	  ring->desc[j].offset = buffer_offset + (slot * mif->buffer_size);
+	  ring->desc[j].buffer_length = mif->buffer_size;
+	}
+    }
+  for (i = 0; i < mif->num_m2s_rings; i++)
+    {
+      ring = memif_get_ring (mif, MEMIF_RING_M2S, i);
+      ring->head = ring->tail = 0;
+      for (j = 0; j < (1 << mif->log2_ring_size); j++)
+	{
+	  u16 slot =
+	    (i + mif->num_s2m_rings) * (1 << mif->log2_ring_size) + j;
+	  ring->desc[j].region = 0;
+	  ring->desc[j].offset = buffer_offset + (slot * mif->buffer_size);
+	  ring->desc[j].buffer_length = mif->buffer_size;
+	}
+    }
+
+  iov[0].iov_base = (void *) &msg;
+  iov[0].iov_len = sizeof (memif_msg_t);
+  mh.msg_iov = iov;
+  mh.msg_iovlen = 1;
+
+  /* create interrupt socket */
+  if (socketpair (AF_UNIX, SOCK_STREAM, 0, fd_array) < 0)
+    {
+      DEBUG_UNIX_LOG ("Failed to create a pair of connected sockets");
+      goto error;
+    }
+
+  mif->interrupt_line.fd = fd_array[0];
+  template.read_function = memif_int_fd_read_ready;
+  template.file_descriptor = mif->interrupt_line.fd;
+  template.private_data = mif->if_index;
+  mif->interrupt_line.index = unix_file_add (&unix_main, &template);
+
+  memset (&ctl, 0, sizeof (ctl));
+  mh.msg_control = ctl;
+  mh.msg_controllen = sizeof (ctl);
+  cmsg = CMSG_FIRSTHDR (&mh);
+  cmsg->cmsg_len = CMSG_LEN (sizeof (fd_array));
+  cmsg->cmsg_level = SOL_SOCKET;
+  cmsg->cmsg_type = SCM_RIGHTS;
+  fd_array[0] = mfd;
+  clib_memcpy (CMSG_DATA (cmsg), fd_array, sizeof (fd_array));
+
+  mif->flags |= MEMIF_IF_FLAG_CONNECTING;
+  rv = sendmsg (mif->connection.fd, &mh, 0);
+  if (rv < 0)
+    {
+      DEBUG_UNIX_LOG ("Failed to send memif connection request");
+      goto error;
+    }
+
+  /* No need to keep the descriptor open,
+   * mmap creates an extra reference to the underlying file */
+  close (mfd);
+  mfd = -1;
+  /* This FD is given to peer, so we can close it */
+  close (fd_array[1]);
+  fd_array[1] = -1;
+  return;
+
+error:
+  if (mfd > -1)
+    close (mfd);
+  if (fd_array[1] > -1)
+    close (fd_array[1]);
+  memif_disconnect (vm, mif);
+}
+
+static uword
+memif_process (vlib_main_t * vm, vlib_node_runtime_t * rt, vlib_frame_t * f)
+{
+  memif_main_t *mm = &memif_main;
+  memif_if_t *mif;
+  struct sockaddr_un sun;
+  int sockfd;
+  uword *event_data = 0, event_type;
+  unix_file_t template = { 0 };
+  u8 enabled = 0;
+  f64 start_time, last_run_duration = 0, now;
+
+  sockfd = socket (AF_UNIX, SOCK_STREAM, 0);
+  sun.sun_family = AF_UNIX;
+  template.read_function = memif_conn_fd_read_ready;
+
+  while (1)
+    {
+      if (enabled)
+	vlib_process_wait_for_event_or_clock (vm,
+					      (f64) 3 - last_run_duration);
+      else
+	vlib_process_wait_for_event (vm);
+
+      event_type = vlib_process_get_events (vm, &event_data);
+      vec_reset_length (event_data);
+
+      switch (event_type)
+	{
+	case ~0:
+	  break;
+	case MEMIF_PROCESS_EVENT_START:
+	  enabled = 1;
+	  break;
+	case MEMIF_PROCESS_EVENT_STOP:
+	  enabled = 0;
+	  continue;
+	default:
+	  ASSERT (0);
+	}
+
+      last_run_duration = start_time = vlib_time_now (vm);
+      /* *INDENT-OFF* */
+      pool_foreach (mif, mm->interfaces,
+        ({
+	  /* Allow no more than 10us without a pause */
+	  now = vlib_time_now (vm);
+	  if (now > start_time + 10e-6)
+	    {
+	      vlib_process_suspend (vm, 100e-6);	/* suspend for 100 us */
+	      start_time = vlib_time_now (vm);
+	    }
+
+	  if ((mif->flags & MEMIF_IF_FLAG_ADMIN_UP) == 0)
+	    continue;
+
+	  if (mif->flags & MEMIF_IF_FLAG_CONNECTING)
+	    continue;
+
+	  if (mif->flags & MEMIF_IF_FLAG_CONNECTED)
+	    continue;
+
+	  if (mif->flags & MEMIF_IF_FLAG_IS_SLAVE)
+	    {
+	      strncpy (sun.sun_path, (char *) mif->socket_filename,
+		       sizeof (sun.sun_path) - 1);
+
+	      if (connect
+		  (sockfd, (struct sockaddr *) &sun,
+		   sizeof (struct sockaddr_un)) == 0)
+	        {
+		  mif->connection.fd = sockfd;
+		  template.file_descriptor = sockfd;
+		  template.private_data = mif->if_index << 1;
+		  mif->connection.index = unix_file_add (&unix_main, &template);
+		  memif_connect_master (vm, mif);
+
+		  /* grab another fd */
+		  sockfd = socket (AF_UNIX, SOCK_STREAM, 0);
+		  if (sockfd < 0)
+		    {
+		      DEBUG_UNIX_LOG ("socket AF_UNIX");
+		      return 0;
+		    }
+	        }
+	    }
+        }));
+      /* *INDENT-ON* */
+      last_run_duration = vlib_time_now (vm) - last_run_duration;
+    }
+  return 0;
+}
+
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (memif_process_node,static) = {
+  .function = memif_process,
+  .type = VLIB_NODE_TYPE_PROCESS,
+  .name = "memif-process",
+};
+/* *INDENT-ON* */
+
+static void
+memif_close_if (memif_main_t * mm, memif_if_t * mif)
+{
+  vlib_main_t *vm = vlib_get_main ();
+  memif_listener_t *listener = 0;
+  memif_pending_conn_t *pending_conn = 0;
+
+  memif_disconnect (vm, mif);
+
+  if (mif->listener_index != (uword) ~ 0)
+    {
+      listener = pool_elt_at_index (mm->listeners, mif->listener_index);
+      if (--listener->usage_counter == 0)
+	{
+	  /* not used anymore -> remove the socket and pending connections */
+
+	  /* *INDENT-OFF* */
+	  pool_foreach (pending_conn, mm->pending_conns,
+	    ({
+	       if (pending_conn->listener_index == mif->listener_index)
+	         {
+		   memif_remove_pending_conn (pending_conn);
+	         }
+	     }));
+          /* *INDENT-ON* */
+
+	  unix_file_del (&unix_main,
+			 unix_main.file_pool + listener->socket.index);
+	  pool_put (mm->listeners, listener);
+	  unlink ((char *) mif->socket_filename);
+	}
+    }
+
+  if (mif->lockp != 0)
+    {
+      clib_mem_free ((void *) mif->lockp);
+      mif->lockp = 0;
+    }
+
+  mhash_unset (&mm->if_index_by_key, &mif->key, &mif->if_index);
+  vec_free (mif->socket_filename);
+  vec_free (mif->ring_data);
+
+  memset (mif, 0, sizeof (*mif));
+  pool_put (mm->interfaces, mif);
+}
+
+int
+memif_worker_thread_enable ()
+{
+  /* if worker threads are enabled, switch to polling mode */
+  foreach_vlib_main ((
+		       {
+		       vlib_node_set_state (this_vlib_main,
+					    memif_input_node.index,
+					    VLIB_NODE_STATE_POLLING);
+		       }));
+
+  return 0;
+}
+
+int
+memif_worker_thread_disable ()
+{
+  foreach_vlib_main ((
+		       {
+		       vlib_node_set_state (this_vlib_main,
+					    memif_input_node.index,
+					    VLIB_NODE_STATE_INTERRUPT);
+		       }));
+
+  return 0;
+}
+
+int
+memif_create_if (vlib_main_t * vm, memif_create_if_args_t * args)
+{
+  memif_main_t *mm = &memif_main;
+  vlib_thread_main_t *tm = vlib_get_thread_main ();
+  vnet_main_t *vnm = vnet_get_main ();
+  memif_if_t *mif = 0;
+  vnet_sw_interface_t *sw;
+  clib_error_t *error = 0;
+  int ret = 0;
+  uword *p;
+
+  p = mhash_get (&mm->if_index_by_key, &args->key);
+  if (p)
+    return VNET_API_ERROR_SUBIF_ALREADY_EXISTS;
+
+  pool_get (mm->interfaces, mif);
+  memset (mif, 0, sizeof (*mif));
+  mif->key = args->key;
+  mif->if_index = mif - mm->interfaces;
+  mif->sw_if_index = mif->hw_if_index = mif->per_interface_next_index = ~0;
+  mif->listener_index = ~0;
+  mif->connection.index = mif->interrupt_line.index = ~0;
+  mif->connection.fd = mif->interrupt_line.fd = -1;
+
+  if (tm->n_vlib_mains > 1)
+    {
+      mif->lockp = clib_mem_alloc_aligned (CLIB_CACHE_LINE_BYTES,
+					   CLIB_CACHE_LINE_BYTES);
+      memset ((void *) mif->lockp, 0, CLIB_CACHE_LINE_BYTES);
+    }
+
+  if (!args->hw_addr_set)
+    {
+      f64 now = vlib_time_now (vm);
+      u32 rnd;
+      rnd = (u32) (now * 1e6);
+      rnd = random_u32 (&rnd);
+
+      memcpy (args->hw_addr + 2, &rnd, sizeof (rnd));
+      args->hw_addr[0] = 2;
+      args->hw_addr[1] = 0xfe;
+    }
+
+  error = ethernet_register_interface (vnm, memif_device_class.index,
+				       mif->if_index, args->hw_addr,
+				       &mif->hw_if_index,
+				       memif_eth_flag_change);
+
+  if (error)
+    {
+      clib_error_report (error);
+      ret = VNET_API_ERROR_SYSCALL_ERROR_1;
+      goto error;
+    }
+
+  sw = vnet_get_hw_sw_interface (vnm, mif->hw_if_index);
+  mif->sw_if_index = sw->sw_if_index;
+
+  mif->log2_ring_size = args->log2_ring_size;
+  mif->buffer_size = args->buffer_size;
+
+  /* TODO: make configurable */
+  mif->num_s2m_rings = 1;
+  mif->num_m2s_rings = 1;
+
+  mhash_set_mem (&mm->if_index_by_key, &args->key, &mif->if_index, 0);
+
+  if (args->socket_filename != 0)
+    mif->socket_filename = args->socket_filename;
+  else
+    mif->socket_filename = vec_dup (mm->default_socket_filename);
+
+  args->sw_if_index = mif->sw_if_index;
+
+  if (args->is_master)
+    {
+      struct sockaddr_un un = { 0 };
+      struct stat file_stat;
+      int on = 1;
+      memif_listener_t *listener = 0;
+
+      if (stat ((char *) mif->socket_filename, &file_stat) == 0)
+	{
+	  if (!S_ISSOCK (file_stat.st_mode))
+	    {
+	      errno = ENOTSOCK;
+	      ret = VNET_API_ERROR_SYSCALL_ERROR_2;
+	      goto error;
+	    }
+	  /* *INDENT-OFF* */
+	  pool_foreach (listener, mm->listeners,
+	    ({
+	       if (listener->sock_dev == file_stat.st_dev &&
+		   listener->sock_ino == file_stat.st_ino)
+	         {
+		   /* attach memif to the existing listener */
+		   mif->listener_index = listener->index;
+		   ++listener->usage_counter;
+		   goto signal;
+	         }
+	     }));
+          /* *INDENT-ON* */
+	  unlink ((char *) mif->socket_filename);
+	}
+
+      pool_get (mm->listeners, listener);
+      memset (listener, 0, sizeof (*listener));
+      listener->socket.fd = -1;
+      listener->socket.index = ~0;
+      listener->index = listener - mm->listeners;
+      listener->usage_counter = 1;
+
+      if ((listener->socket.fd = socket (AF_UNIX, SOCK_STREAM, 0)) < 0)
+	{
+	  ret = VNET_API_ERROR_SYSCALL_ERROR_3;
+	  goto error;
+	}
+
+      un.sun_family = AF_UNIX;
+      strncpy ((char *) un.sun_path, (char *) mif->socket_filename,
+	       sizeof (un.sun_path) - 1);
+
+      if (setsockopt (listener->socket.fd, SOL_SOCKET, SO_PASSCRED,
+		      &on, sizeof (on)) < 0)
+	{
+	  ret = VNET_API_ERROR_SYSCALL_ERROR_4;
+	  goto error;
+	}
+      if (bind (listener->socket.fd, (struct sockaddr *) &un,
+		sizeof (un)) == -1)
+	{
+	  ret = VNET_API_ERROR_SYSCALL_ERROR_5;
+	  goto error;
+	}
+      if (listen (listener->socket.fd, 1) == -1)
+	{
+	  ret = VNET_API_ERROR_SYSCALL_ERROR_6;
+	  goto error;
+	}
+
+      if (stat ((char *) mif->socket_filename, &file_stat) == -1)
+	{
+	  ret = VNET_API_ERROR_SYSCALL_ERROR_7;
+	  goto error;
+	}
+
+      listener->sock_dev = file_stat.st_dev;
+      listener->sock_ino = file_stat.st_ino;
+
+      unix_file_t template = { 0 };
+      template.read_function = memif_conn_fd_accept_ready;
+      template.file_descriptor = listener->socket.fd;
+      template.private_data = listener->index;
+      listener->socket.index = unix_file_add (&unix_main, &template);
+
+      mif->listener_index = listener->index;
+    }
+  else
+    {
+      mif->flags |= MEMIF_IF_FLAG_IS_SLAVE;
+    }
+
+#if 0
+  /* use configured or generate random MAC address */
+  if (!args->hw_addr_set &&
+      tm->n_vlib_mains > 1 && pool_elts (mm->interfaces) == 1)
+    memif_worker_thread_enable ();
+#endif
+
+signal:
+  if (pool_elts (mm->interfaces) == 1)
+    {
+      vlib_process_signal_event (vm, memif_process_node.index,
+				 MEMIF_PROCESS_EVENT_START, 0);
+    }
+  return 0;
+
+error:
+  if (mif->hw_if_index != ~0)
+    {
+      ethernet_delete_interface (vnm, mif->hw_if_index);
+      mif->hw_if_index = ~0;
+    }
+  memif_close_if (mm, mif);
+  return ret;
+}
+
+int
+memif_delete_if (vlib_main_t * vm, u64 key)
+{
+  vnet_main_t *vnm = vnet_get_main ();
+  memif_main_t *mm = &memif_main;
+  memif_if_t *mif;
+  uword *p;
+
+  p = mhash_get (&mm->if_index_by_key, &key);
+  if (p == NULL)
+    {
+      clib_warning ("Memory interface with key 0x%" PRIx64 " does not exist",
+		    key);
+      return VNET_API_ERROR_SYSCALL_ERROR_1;
+    }
+  mif = pool_elt_at_index (mm->interfaces, p[0]);
+  mif->flags |= MEMIF_IF_FLAG_DELETING;
+
+  /* bring down the interface */
+  vnet_hw_interface_set_flags (vnm, mif->hw_if_index, 0);
+  vnet_sw_interface_set_flags (vnm, mif->sw_if_index, 0);
+
+  /* remove the interface */
+  ethernet_delete_interface (vnm, mif->hw_if_index);
+  mif->hw_if_index = ~0;
+  memif_close_if (mm, mif);
+
+  if (pool_elts (mm->interfaces) == 0)
+    {
+      vlib_process_signal_event (vm, memif_process_node.index,
+				 MEMIF_PROCESS_EVENT_STOP, 0);
+    }
+
+#if 0
+  if (tm->n_vlib_mains > 1 && pool_elts (mm->interfaces) == 0)
+    memif_worker_thread_disable ();
+#endif
+
+  return 0;
+}
+
+static clib_error_t *
+memif_init (vlib_main_t * vm)
+{
+  memif_main_t *mm = &memif_main;
+  vlib_thread_main_t *tm = vlib_get_thread_main ();
+  vlib_thread_registration_t *tr;
+  uword *p;
+
+  memset (mm, 0, sizeof (memif_main_t));
+
+  mm->input_cpu_first_index = 0;
+  mm->input_cpu_count = 1;
+
+  /* initialize binary API */
+  memif_plugin_api_hookup (vm);
+
+  /* find out which cpus will be used for input */
+  p = hash_get_mem (tm->thread_registrations_by_name, "workers");
+  tr = p ? (vlib_thread_registration_t *) p[0] : 0;
+
+  if (tr && tr->count > 0)
+    {
+      mm->input_cpu_first_index = tr->first_index;
+      mm->input_cpu_count = tr->count;
+    }
+
+  mhash_init (&mm->if_index_by_key, sizeof (uword), sizeof (u64));
+
+  vec_validate_aligned (mm->rx_buffers, tm->n_vlib_mains - 1,
+			CLIB_CACHE_LINE_BYTES);
+
+  /* set default socket filename */
+  vec_validate (mm->default_socket_filename,
+		strlen (MEMIF_DEFAULT_SOCKET_FILENAME));
+  strncpy ((char *) mm->default_socket_filename,
+	   MEMIF_DEFAULT_SOCKET_FILENAME,
+	   vec_len (mm->default_socket_filename) - 1);
+
+  return 0;
+}
+
+VLIB_INIT_FUNCTION (memif_init);
+
+/* *INDENT-OFF* */
+VLIB_PLUGIN_REGISTER () = {
+    .version = VPP_BUILD_VER,
+    .description = "Packet Memory Interface (experimetal)",
+};
+/* *INDENT-ON* */
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */
diff --git a/src/plugins/memif/memif.h b/src/plugins/memif/memif.h
new file mode 100644
index 00000000000..a7a88e07b0e
--- /dev/null
+++ b/src/plugins/memif/memif.h
@@ -0,0 +1,263 @@
+/*
+ *------------------------------------------------------------------
+ * Copyright (c) 2016 Cisco 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.
+ *------------------------------------------------------------------
+ */
+
+typedef struct
+{
+  u16 version;
+#define MEMIF_VERSION_MAJOR 0
+#define MEMIF_VERSION_MINOR 1
+#define MEMIF_VERSION ((MEMIF_VERSION_MAJOR << 8) | MEMIF_VERSION_MINOR)
+  u8 type;
+#define MEMIF_MSG_TYPE_CONNECT_REQ  0
+#define MEMIF_MSG_TYPE_CONNECT_RESP 1
+#define MEMIF_MSG_TYPE_DISCONNECT   2
+
+  /* Connection-request parameters: */
+  u64 key;
+  u8 log2_ring_size;
+#define MEMIF_DEFAULT_RING_SIZE 1024
+  u16 num_s2m_rings;
+  u16 num_m2s_rings;
+  u16 buffer_size;
+#define MEMIF_DEFAULT_BUFFER_SIZE 2048
+  u32 shared_mem_size;
+
+  /* Connection-response parameters: */
+  u8 retval;
+} memif_msg_t;
+
+typedef struct __attribute__ ((packed))
+{
+  u16 flags;
+#define MEMIF_DESC_FLAG_NEXT (1 << 0)
+  u16 region;
+  u32 buffer_length;
+  u32 length;;
+  u8 reserved[4];
+  u64 offset;
+  u64 metadata;
+} memif_desc_t;
+
+STATIC_ASSERT_SIZEOF (memif_desc_t, 32);
+
+typedef struct
+{
+  u16 head __attribute__ ((aligned (128)));
+  u16 tail __attribute__ ((aligned (128)));
+  memif_desc_t desc[0] __attribute__ ((aligned (128)));
+} memif_ring_t;
+
+typedef struct
+{
+  u32 cookie __attribute__ ((aligned (128)));
+} memif_shm_t;
+
+
+typedef struct
+{
+  u16 last_head;
+  u16 last_tail;
+} memif_ring_data_t;
+
+typedef struct
+{
+  int fd;
+  u32 index;
+} memif_file_t;
+
+typedef struct
+{
+  uword index;
+  dev_t sock_dev;
+  ino_t sock_ino;
+  memif_file_t socket;
+  u16 usage_counter;
+} memif_listener_t;
+
+typedef struct
+{
+  uword index;
+  memif_file_t connection;
+  uword listener_index;
+} memif_pending_conn_t;
+
+typedef struct
+{
+  CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
+  volatile u32 *lockp;
+  u32 flags;
+#define MEMIF_IF_FLAG_ADMIN_UP   (1 << 0)
+#define MEMIF_IF_FLAG_IS_SLAVE   (1 << 1)
+#define MEMIF_IF_FLAG_CONNECTING (1 << 2)
+#define MEMIF_IF_FLAG_CONNECTED  (1 << 3)
+#define MEMIF_IF_FLAG_DELETING   (1 << 4)
+
+  u64 key;
+  uword if_index;
+  u32 hw_if_index;
+  u32 sw_if_index;
+
+  u32 per_interface_next_index;
+
+  uword listener_index;
+  memif_file_t connection;
+  memif_file_t interrupt_line;
+  u8 *socket_filename;
+
+  void **regions;
+
+  u8 log2_ring_size;
+  u8 num_s2m_rings;
+  u8 num_m2s_rings;
+  u16 buffer_size;
+
+  memif_ring_data_t *ring_data;
+
+  /* remote info */
+  pid_t remote_pid;
+  uid_t remote_uid;
+} memif_if_t;
+
+typedef struct
+{
+  CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
+
+  /** API message ID base */
+  u16 msg_id_base;
+
+  /* pool of all memory interfaces */
+  memif_if_t *interfaces;
+
+  /* pool of all listeners */
+  memif_listener_t *listeners;
+
+  /* pool of pending connections */
+  memif_pending_conn_t *pending_conns;
+
+  /* bitmap of pending rx interfaces */
+  uword *pending_input_bitmap;
+
+  /* rx buffer cache */
+  u32 **rx_buffers;
+
+  /* hash of all registered keys */
+  mhash_t if_index_by_key;
+
+  /* first cpu index */
+  u32 input_cpu_first_index;
+
+  /* total cpu count */
+  u32 input_cpu_count;
+
+  /* configuration */
+  u8 *default_socket_filename;
+#define MEMIF_DEFAULT_SOCKET_FILENAME  "/var/vpp/memif.sock"
+} memif_main_t;
+
+extern memif_main_t memif_main;
+extern vnet_device_class_t memif_device_class;
+extern vlib_node_registration_t memif_input_node;
+
+enum
+{
+  MEMIF_PROCESS_EVENT_START = 1,
+  MEMIF_PROCESS_EVENT_STOP = 2,
+} memif_process_event_t;
+
+typedef struct
+{
+  u64 key;
+  u8 *socket_filename;
+  u8 is_master;
+  u8 log2_ring_size;
+  u16 buffer_size;
+  u8 hw_addr_set;
+  u8 hw_addr[6];
+
+  /* return */
+  u32 sw_if_index;
+} memif_create_if_args_t;
+
+int memif_create_if (vlib_main_t * vm, memif_create_if_args_t * args);
+int memif_delete_if (vlib_main_t * vm, u64 key);
+clib_error_t *memif_plugin_api_hookup (vlib_main_t * vm);
+
+#ifndef __NR_memfd_create
+#if defined __x86_64__
+#define __NR_memfd_create 319
+#elif defined __arm__
+#define __NR_memfd_create 385
+#elif defined __aarch64__
+#define __NR_memfd_create 279
+#else
+#error "__NR_memfd_create unknown for this architecture"
+#endif
+#endif
+
+static inline int
+memfd_create (const char *name, unsigned int flags)
+{
+  return syscall (__NR_memfd_create, name, flags);
+}
+
+typedef enum
+{
+  MEMIF_RING_S2M = 0,
+  MEMIF_RING_M2S = 1
+} memif_ring_type_t;
+
+static_always_inline memif_ring_t *
+memif_get_ring (memif_if_t * mif, memif_ring_type_t type, u16 ring_num)
+{
+  if (vec_len (mif->regions) == 0)
+    return NULL;
+  void *p = mif->regions[0];
+  int ring_size =
+    sizeof (memif_ring_t) +
+    sizeof (memif_desc_t) * (1 << mif->log2_ring_size);
+  p += sizeof (memif_shm_t);
+  p += (ring_num + type * mif->num_s2m_rings) * ring_size;
+
+  return (memif_ring_t *) p;
+}
+
+static_always_inline void *
+memif_get_buffer (memif_if_t * mif, memif_ring_t * ring, u16 slot)
+{
+  u16 region = ring->desc[slot].region;
+  return mif->regions[region] + ring->desc[slot].offset;
+}
+
+#ifndef F_LINUX_SPECIFIC_BASE
+#define F_LINUX_SPECIFIC_BASE 1024
+#endif
+#define MFD_ALLOW_SEALING       0x0002U
+#define F_ADD_SEALS (F_LINUX_SPECIFIC_BASE + 9)
+#define F_GET_SEALS (F_LINUX_SPECIFIC_BASE + 10)
+
+#define F_SEAL_SEAL     0x0001	/* prevent further seals from being set */
+#define F_SEAL_SHRINK   0x0002	/* prevent file from shrinking */
+#define F_SEAL_GROW     0x0004	/* prevent file from growing */
+#define F_SEAL_WRITE    0x0008	/* prevent writes */
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */
diff --git a/src/plugins/memif/memif_all_api_h.h b/src/plugins/memif/memif_all_api_h.h
new file mode 100644
index 00000000000..9729ec16239
--- /dev/null
+++ b/src/plugins/memif/memif_all_api_h.h
@@ -0,0 +1,18 @@
+/*
+ * memif_all_api_h.h - plug-in api #include file
+ *
+ * Copyright (c) <current-year> <your-organization>
+ * 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.
+ */
+/* Include the generated file, see BUILT_SOURCES in Makefile.am */
+#include <memif/memif.api.h>
diff --git a/src/plugins/memif/memif_api.c b/src/plugins/memif/memif_api.c
new file mode 100644
index 00000000000..1ade317e26f
--- /dev/null
+++ b/src/plugins/memif/memif_api.c
@@ -0,0 +1,332 @@
+/*
+ *------------------------------------------------------------------
+ * memif_api.c - memif api
+ *
+ * Copyright (c) 2017 Cisco 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.
+ *------------------------------------------------------------------
+ */
+
+#include <vlib/vlib.h>
+#include <vnet/ethernet/ethernet.h>
+#include <memif/memif.h>
+
+#include <vlibapi/api.h>
+#include <vlibmemory/api.h>
+#include <vlibsocket/api.h>
+
+/* define message IDs */
+#include <memif/memif_msg_enum.h>
+
+/* define message structures */
+#define vl_typedefs
+#include <memif/memif_all_api_h.h>
+#undef vl_typedefs
+
+/* define generated endian-swappers */
+#define vl_endianfun
+#include <memif/memif_all_api_h.h>
+#undef vl_endianfun
+
+/* instantiate all the print functions we know about */
+#define vl_print(handle, ...) vlib_cli_output (handle, __VA_ARGS__)
+#define vl_printfun
+#include <memif/memif_all_api_h.h>
+#undef vl_printfun
+
+/* Get the API version number */
+#define vl_api_version(n,v) static u32 api_version=(v);
+#include <memif/memif_all_api_h.h>
+#undef vl_api_version
+
+/*
+ * A handy macro to set up a message reply.
+ * Assumes that the following variables are available:
+ * mp - pointer to request message
+ * rmp - pointer to reply message type
+ * rv - return value
+ */
+#define REPLY_MACRO(t)                                          \
+do {                                                            \
+    unix_shared_memory_queue_t * q =                            \
+    vl_api_client_index_to_input_queue (mp->client_index);      \
+    if (!q)                                                     \
+        return;                                                 \
+                                                                \
+    rmp = vl_msg_api_alloc (sizeof (*rmp));                     \
+    rmp->_vl_msg_id = htons ((t)+mm->msg_id_base);              \
+    rmp->context = mp->context;                                 \
+    rmp->retval = htonl (rv);                                   \
+                                                                \
+    vl_msg_api_send_shmem (q, (u8 *)&rmp);                      \
+} while(0);
+
+#define REPLY_MACRO2(t, body)                                   \
+do {                                                            \
+    unix_shared_memory_queue_t * q =                            \
+    vl_api_client_index_to_input_queue (mp->client_index);      \
+    if (!q)                                                     \
+        return;                                                 \
+                                                                \
+    rmp = vl_msg_api_alloc (sizeof (*rmp));                     \
+    rmp->_vl_msg_id = htons ((t)+mm->msg_id_base);              \
+    rmp->context = mp->context;                                 \
+    rmp->retval = htonl (rv);                                   \
+    do {body;} while (0);                                       \
+    vl_msg_api_send_shmem (q, (u8 *)&rmp);                      \
+} while(0);
+
+#define foreach_memif_plugin_api_msg                     \
+_(MEMIF_CREATE, memif_create)                            \
+_(MEMIF_DELETE, memif_delete)                            \
+_(MEMIF_DETAILS, memif_details)                          \
+_(MEMIF_DUMP, memif_dump)                                \
+
+/**
+ * @brief Message handler for memif_create API.
+ * @param mp vl_api_memif_create_t * mp the api message
+ */
+void
+vl_api_memif_create_t_handler (vl_api_memif_create_t * mp)
+{
+  memif_main_t *mm = &memif_main;
+  vlib_main_t *vm = vlib_get_main ();
+  vl_api_memif_create_reply_t *rmp;
+  memif_create_if_args_t args = { 0 };
+  u32 ring_size = MEMIF_DEFAULT_RING_SIZE;
+  static const u8 empty_hw_addr[6];
+  int rv = 0;
+
+  /* key */
+  args.key = clib_net_to_host_u64 (mp->key);
+
+  /* socket filename */
+  mp->socket_filename[ARRAY_LEN (mp->socket_filename) - 1] = 0;
+  if (strlen ((char *) mp->socket_filename) > 0)
+    {
+      vec_validate (args.socket_filename,
+		    strlen ((char *) mp->socket_filename));
+      strncpy ((char *) args.socket_filename, (char *) mp->socket_filename,
+	       vec_len (args.socket_filename));
+    }
+
+  /* role */
+  args.is_master = (mp->role == 0);
+
+  /* ring size */
+  if (mp->ring_size)
+    {
+      ring_size = ntohl (mp->ring_size);
+    }
+  if (!is_pow2 (ring_size))
+    {
+      rv = VNET_API_ERROR_INVALID_ARGUMENT;
+      goto reply;
+    }
+  args.log2_ring_size = min_log2 (ring_size);
+
+  /* buffer size */
+  args.buffer_size = MEMIF_DEFAULT_BUFFER_SIZE;
+  if (mp->buffer_size)
+    {
+      args.buffer_size = ntohs (mp->buffer_size);
+    }
+
+  /* MAC address */
+  if (memcmp (mp->hw_addr, empty_hw_addr, 6) != 0)
+    {
+      memcpy (args.hw_addr, mp->hw_addr, 6);
+      args.hw_addr_set = 1;
+    }
+
+  rv = memif_create_if (vm, &args);
+
+reply:
+  /* *INDENT-OFF* */
+  REPLY_MACRO2 (VL_API_MEMIF_CREATE_REPLY,
+    ({
+       rmp->sw_if_index = htonl (args.sw_if_index);
+    }));
+  /* *INDENT-ON* */
+}
+
+/**
+ * @brief Message handler for memif_delete API.
+ * @param mp vl_api_memif_delete_t * mp the api message
+ */
+void
+vl_api_memif_delete_t_handler (vl_api_memif_delete_t * mp)
+{
+  memif_main_t *mm = &memif_main;
+  memif_if_t *mif;
+  vlib_main_t *vm = vlib_get_main ();
+  vl_api_memif_delete_reply_t *rmp;
+  u32 sw_if_index = ntohl (mp->sw_if_index);
+  int rv = 0;
+
+  /* *INDENT-OFF* */
+  pool_foreach (mif, mm->interfaces,
+    ({
+      if (sw_if_index == mif->sw_if_index)
+	{
+	  rv = memif_delete_if (vm, mif->key);
+	  goto reply;
+	}
+    }));
+  /* *INDENT-ON* */
+
+  rv = VNET_API_ERROR_INVALID_SW_IF_INDEX;
+
+reply:
+  REPLY_MACRO (VL_API_MEMIF_DELETE_REPLY);
+}
+
+static void
+send_memif_details (unix_shared_memory_queue_t * q,
+		    memif_if_t * mif,
+		    vnet_sw_interface_t * swif,
+		    u8 * interface_name, u32 context)
+{
+  vl_api_memif_details_t *mp;
+  vnet_main_t *vnm = vnet_get_main ();
+  memif_main_t *mm = &memif_main;
+  vnet_hw_interface_t *hwif;
+
+  hwif = vnet_get_sup_hw_interface (vnm, swif->sw_if_index);
+
+  mp = vl_msg_api_alloc (sizeof (*mp));
+  memset (mp, 0, sizeof (*mp));
+
+  mp->_vl_msg_id = htons (VL_API_MEMIF_DETAILS + mm->msg_id_base);
+  mp->context = context;
+
+  mp->sw_if_index = htonl (swif->sw_if_index);
+  strncpy ((char *) mp->if_name,
+	   (char *) interface_name, ARRAY_LEN (mp->if_name) - 1);
+  memcpy (mp->hw_addr, hwif->hw_address, ARRAY_LEN (mp->hw_addr));
+
+  mp->key = clib_host_to_net_u64 (mif->key);
+  mp->role = (mif->flags & MEMIF_IF_FLAG_IS_SLAVE) ? 1 : 0;
+  strncpy ((char *) mp->socket_filename,
+	   (char *) mif->socket_filename,
+	   ARRAY_LEN (mp->socket_filename) - 1);
+
+  mp->ring_size = htonl (1 << mif->log2_ring_size);
+  mp->buffer_size = htons (mif->buffer_size);
+
+  mp->admin_up_down = (swif->flags & VNET_SW_INTERFACE_FLAG_ADMIN_UP) ? 1 : 0;
+  mp->link_up_down = (hwif->flags & VNET_HW_INTERFACE_FLAG_LINK_UP) ? 1 : 0;
+
+  vl_msg_api_send_shmem (q, (u8 *) & mp);
+}
+
+/**
+ * @brief Message handler for memif_dump API.
+ * @param mp vl_api_memif_dump_t * mp the api message
+ */
+void
+vl_api_memif_dump_t_handler (vl_api_memif_dump_t * mp)
+{
+  memif_main_t *mm = &memif_main;
+  vnet_main_t *vnm = vnet_get_main ();
+  vnet_sw_interface_t *swif;
+  memif_if_t *mif;
+  u8 *if_name = 0;
+  unix_shared_memory_queue_t *q;
+
+  q = vl_api_client_index_to_input_queue (mp->client_index);
+  if (q == 0)
+    return;
+
+  /* *INDENT-OFF* */
+  pool_foreach (mif, mm->interfaces,
+    ({
+      swif = vnet_get_sw_interface (vnm, mif->sw_if_index);
+
+      if_name = format (if_name, "%U%c",
+			format_vnet_sw_interface_name,
+			vnm, swif, 0);
+
+      send_memif_details (q, mif, swif, if_name, mp->context);
+      _vec_len (if_name) = 0;
+    }));
+  /* *INDENT-ON* */
+
+  vec_free (if_name);
+}
+
+/**
+ * @brief Message handler for memif_details API.
+ * @param mp vl_api_memif_details_t * mp the api message
+ */
+void
+vl_api_memif_details_t_handler (vl_api_memif_details_t * mp)
+{
+  clib_warning ("BUG");
+}
+
+#define vl_msg_name_crc_list
+#include <memif/memif_all_api_h.h>
+#undef vl_msg_name_crc_list
+
+static void
+setup_message_id_table (memif_main_t * mm, api_main_t * am)
+{
+#define _(id,n,crc) \
+  vl_msg_api_add_msg_name_crc (am, #n "_" #crc, id + mm->msg_id_base);
+  foreach_vl_msg_name_crc_memif;
+#undef _
+}
+
+/* Set up the API message handling tables */
+clib_error_t *
+memif_plugin_api_hookup (vlib_main_t * vm)
+{
+  memif_main_t *mm = &memif_main;
+  api_main_t *am = &api_main;
+  u8 *name;
+
+  /* Construct the API name */
+  name = format (0, "memif_%08x%c", api_version, 0);
+
+  /* Ask for a correctly-sized block of API message decode slots */
+  mm->msg_id_base = vl_msg_api_get_msg_ids
+    ((char *) name, VL_MSG_FIRST_AVAILABLE);
+
+#define _(N,n)                                                  \
+    vl_msg_api_set_handlers((VL_API_##N + mm->msg_id_base),     \
+                           #n,                                  \
+                           vl_api_##n##_t_handler,              \
+                           vl_noop_handler,                     \
+                           vl_api_##n##_t_endian,               \
+                           vl_api_##n##_t_print,                \
+                           sizeof(vl_api_##n##_t), 1);
+  foreach_memif_plugin_api_msg;
+#undef _
+
+  /*
+   * Set up the (msg_name, crc, message-id) table
+   */
+  setup_message_id_table (mm, am);
+
+  vec_free (name);
+  return 0;
+}
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */
diff --git a/src/plugins/memif/memif_msg_enum.h b/src/plugins/memif/memif_msg_enum.h
new file mode 100644
index 00000000000..74efee00604
--- /dev/null
+++ b/src/plugins/memif/memif_msg_enum.h
@@ -0,0 +1,31 @@
+/*
+ * memif_msg_enum.h - vpp engine plug-in message enumeration
+ *
+ * Copyright (c) <current-year> <your-organization>
+ * 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.
+ */
+#ifndef included_memif_msg_enum_h
+#define included_memif_msg_enum_h
+
+#include <vppinfra/byte_order.h>
+
+#define vl_msg_id(n,h) n,
+typedef enum
+{
+#include <memif/memif_all_api_h.h>
+  /* We'll want to know how many messages IDs we need... */
+  VL_MSG_FIRST_AVAILABLE,
+} vl_msg_id_t;
+#undef vl_msg_id
+
+#endif /* included_memif_msg_enum_h */
diff --git a/src/plugins/memif/node.c b/src/plugins/memif/node.c
new file mode 100644
index 00000000000..298472b04b7
--- /dev/null
+++ b/src/plugins/memif/node.c
@@ -0,0 +1,383 @@
+/*
+ *------------------------------------------------------------------
+ * Copyright (c) 2016 Cisco 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.
+ *------------------------------------------------------------------
+ */
+
+#define _GNU_SOURCE
+#include <stdint.h>
+#include <net/if.h>
+#include <sys/ioctl.h>
+#include <sys/uio.h>
+
+#include <vlib/vlib.h>
+#include <vlib/unix/unix.h>
+#include <vnet/ethernet/ethernet.h>
+#include <vnet/devices/devices.h>
+#include <vnet/feature/feature.h>
+
+#include <memif/memif.h>
+
+#define foreach_memif_input_error
+
+typedef enum
+{
+#define _(f,s) MEMIF_INPUT_ERROR_##f,
+  foreach_memif_input_error
+#undef _
+    MEMIF_INPUT_N_ERROR,
+} memif_input_error_t;
+
+static char *memif_input_error_strings[] = {
+#define _(n,s) s,
+  foreach_memif_input_error
+#undef _
+};
+
+typedef struct
+{
+  u32 next_index;
+  u32 hw_if_index;
+  u16 ring;
+} memif_input_trace_t;
+
+static u8 *
+format_memif_input_trace (u8 * s, va_list * args)
+{
+  CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
+  CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
+  memif_input_trace_t *t = va_arg (*args, memif_input_trace_t *);
+  uword indent = format_get_indent (s);
+
+  s = format (s, "memif: hw_if_index %d next-index %d",
+	      t->hw_if_index, t->next_index);
+  s = format (s, "\n%Uslot: ring %u", format_white_space, indent + 2,
+	      t->ring);
+  return s;
+}
+
+static_always_inline void
+memif_prefetch (vlib_main_t * vm, u32 bi)
+{
+  vlib_buffer_t *b = vlib_get_buffer (vm, bi);
+  vlib_prefetch_buffer_header (b, STORE);
+  CLIB_PREFETCH (b->data, CLIB_CACHE_LINE_BYTES, STORE);
+}
+
+static_always_inline uword
+memif_device_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
+			   vlib_frame_t * frame, memif_if_t * mif,
+			   memif_ring_type_t type)
+{
+  vnet_main_t *vnm = vnet_get_main ();
+  u8 rid = 0;			/* Ring id */
+  memif_ring_t *ring = memif_get_ring (mif, type, rid);
+  memif_ring_data_t *rd =
+    vec_elt_at_index (mif->ring_data, rid + type * mif->num_s2m_rings);
+  u16 head;
+
+  u32 next_index = VNET_DEVICE_INPUT_NEXT_ETHERNET_INPUT;
+  uword n_trace = vlib_get_trace_count (vm, node);
+  memif_main_t *nm = &memif_main;
+  u32 n_rx_packets = 0;
+  u32 n_rx_bytes = 0;
+  u32 *to_next = 0;
+  u32 n_free_bufs;
+  u32 cpu_index = os_get_cpu_number ();
+  u32 bi0, bi1;
+  vlib_buffer_t *b0, *b1;
+  u16 ring_size = 1 << mif->log2_ring_size;
+  u16 mask = ring_size - 1;
+  u16 num_slots;
+  void *mb0, *mb1;
+
+  if (mif->per_interface_next_index != ~0)
+    next_index = mif->per_interface_next_index;
+
+  n_free_bufs = vec_len (nm->rx_buffers[cpu_index]);
+  if (PREDICT_FALSE (n_free_bufs < ring_size))
+    {
+      vec_validate (nm->rx_buffers[cpu_index], ring_size + n_free_bufs - 1);
+      n_free_bufs +=
+	vlib_buffer_alloc (vm, &nm->rx_buffers[cpu_index][n_free_bufs],
+			   ring_size);
+      _vec_len (nm->rx_buffers[cpu_index]) = n_free_bufs;
+    }
+
+  head = ring->head;
+  if (head == rd->last_head)
+    return 0;
+
+  if (head > rd->last_head)
+    num_slots = head - rd->last_head;
+  else
+    num_slots = ring_size - rd->last_head + head;
+
+  while (num_slots)
+    {
+      u32 n_left_to_next;
+      u32 next0 = next_index;
+      u32 next1 = next_index;
+      vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
+
+      while (num_slots > 5 && n_left_to_next > 2)
+	{
+	  if (PREDICT_TRUE (rd->last_head + 5 < ring_size))
+	    {
+	      CLIB_PREFETCH (memif_get_buffer (mif, ring, rd->last_head + 2),
+			     CLIB_CACHE_LINE_BYTES, LOAD);
+	      CLIB_PREFETCH (memif_get_buffer (mif, ring, rd->last_head + 3),
+			     CLIB_CACHE_LINE_BYTES, LOAD);
+	      CLIB_PREFETCH (&ring->desc[rd->last_head + 4],
+			     CLIB_CACHE_LINE_BYTES, LOAD);
+	      CLIB_PREFETCH (&ring->desc[rd->last_head + 5],
+			     CLIB_CACHE_LINE_BYTES, LOAD);
+	    }
+	  else
+	    {
+	      CLIB_PREFETCH (memif_get_buffer
+			     (mif, ring, (rd->last_head + 2) % mask),
+			     CLIB_CACHE_LINE_BYTES, LOAD);
+	      CLIB_PREFETCH (memif_get_buffer
+			     (mif, ring, (rd->last_head + 3) % mask),
+			     CLIB_CACHE_LINE_BYTES, LOAD);
+	      CLIB_PREFETCH (&ring->desc[(rd->last_head + 4) % mask],
+			     CLIB_CACHE_LINE_BYTES, LOAD);
+	      CLIB_PREFETCH (&ring->desc[(rd->last_head + 5) % mask],
+			     CLIB_CACHE_LINE_BYTES, LOAD);
+	    }
+	  /* get empty buffer */
+	  u32 last_buf = vec_len (nm->rx_buffers[cpu_index]) - 1;
+	  bi0 = nm->rx_buffers[cpu_index][last_buf];
+	  bi1 = nm->rx_buffers[cpu_index][last_buf - 1];
+	  _vec_len (nm->rx_buffers[cpu_index]) -= 2;
+
+	  if (last_buf > 4)
+	    {
+	      memif_prefetch (vm, nm->rx_buffers[cpu_index][last_buf - 2]);
+	      memif_prefetch (vm, nm->rx_buffers[cpu_index][last_buf - 3]);
+	    }
+
+	  /* enqueue buffer */
+	  to_next[0] = bi0;
+	  to_next[1] = bi1;
+	  to_next += 2;
+	  n_left_to_next -= 2;
+
+	  /* fill buffer metadata */
+	  b0 = vlib_get_buffer (vm, bi0);
+	  b1 = vlib_get_buffer (vm, bi1);
+
+	  vnet_buffer (b0)->sw_if_index[VLIB_RX] = mif->sw_if_index;
+	  vnet_buffer (b1)->sw_if_index[VLIB_RX] = mif->sw_if_index;
+
+	  vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
+	  vnet_buffer (b1)->sw_if_index[VLIB_TX] = (u32) ~ 0;
+
+	  /* copy buffer */
+	  mb0 = memif_get_buffer (mif, ring, rd->last_head);
+	  clib_memcpy (vlib_buffer_get_current (b0), mb0,
+		       CLIB_CACHE_LINE_BYTES);
+	  b0->current_length = ring->desc[rd->last_head].length;
+	  rd->last_head = (rd->last_head + 1) & mask;
+
+	  mb1 = memif_get_buffer (mif, ring, rd->last_head);
+	  clib_memcpy (vlib_buffer_get_current (b1), mb1,
+		       CLIB_CACHE_LINE_BYTES);
+	  b1->current_length = ring->desc[rd->last_head].length;
+	  rd->last_head = (rd->last_head + 1) & mask;
+
+	  if (b0->current_length > CLIB_CACHE_LINE_BYTES)
+	    clib_memcpy (vlib_buffer_get_current (b0) + CLIB_CACHE_LINE_BYTES,
+			 mb0 + CLIB_CACHE_LINE_BYTES,
+			 b0->current_length - CLIB_CACHE_LINE_BYTES);
+
+	  if (b1->current_length > CLIB_CACHE_LINE_BYTES)
+	    clib_memcpy (vlib_buffer_get_current (b1) + CLIB_CACHE_LINE_BYTES,
+			 mb1 + CLIB_CACHE_LINE_BYTES,
+			 b1->current_length - CLIB_CACHE_LINE_BYTES);
+
+	  /* trace */
+	  VLIB_BUFFER_TRACE_TRAJECTORY_INIT (b0);
+	  VLIB_BUFFER_TRACE_TRAJECTORY_INIT (b1);
+
+	  if (PREDICT_FALSE (n_trace > 0))
+	    {
+	      if (b0)
+		{
+		  memif_input_trace_t *tr;
+		  vlib_trace_buffer (vm, node, next0, b0,
+				     /* follow_chain */ 0);
+		  vlib_set_trace_count (vm, node, --n_trace);
+		  tr = vlib_add_trace (vm, node, b0, sizeof (*tr));
+		  tr->next_index = next0;
+		  tr->hw_if_index = mif->hw_if_index;
+		  tr->ring = rid;
+		}
+
+	      if (n_trace && b1)
+		{
+		  memif_input_trace_t *tr;
+		  vlib_trace_buffer (vm, node, next1, b1,
+				     /* follow_chain */ 0);
+		  vlib_set_trace_count (vm, node, --n_trace);
+		  tr = vlib_add_trace (vm, node, b1, sizeof (*tr));
+		  tr->next_index = next1;
+		  tr->hw_if_index = mif->hw_if_index;
+		  tr->ring = rid;
+		}
+	    }
+
+	  /* redirect if feature path enabled */
+	  vnet_feature_start_device_input_x2 (mif->sw_if_index,
+					      &next0, &next1, b0, b1);
+
+	  /* enqueue */
+	  vlib_validate_buffer_enqueue_x2 (vm, node, next_index, to_next,
+					   n_left_to_next,
+					   bi0, bi1, next0, next1);
+
+	  /* next packet */
+	  num_slots -= 2;
+	  n_rx_packets += 2;
+	  n_rx_bytes += b0->current_length;
+	  n_rx_bytes += b1->current_length;
+	}
+      while (num_slots && n_left_to_next)
+	{
+	  /* get empty buffer */
+	  u32 last_buf = vec_len (nm->rx_buffers[cpu_index]) - 1;
+	  bi0 = nm->rx_buffers[cpu_index][last_buf];
+	  _vec_len (nm->rx_buffers[cpu_index]) = last_buf;
+
+	  /* enqueue buffer */
+	  to_next[0] = bi0;
+	  to_next += 1;
+	  n_left_to_next--;
+
+	  /* fill buffer metadata */
+	  b0 = vlib_get_buffer (vm, bi0);
+	  b0->current_length = ring->desc[rd->last_head].length;
+	  vnet_buffer (b0)->sw_if_index[VLIB_RX] = mif->sw_if_index;
+	  vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
+
+	  /* copy buffer */
+	  mb0 = memif_get_buffer (mif, ring, rd->last_head);
+	  clib_memcpy (vlib_buffer_get_current (b0), mb0,
+		       CLIB_CACHE_LINE_BYTES);
+	  if (b0->current_length > CLIB_CACHE_LINE_BYTES)
+	    clib_memcpy (vlib_buffer_get_current (b0) + CLIB_CACHE_LINE_BYTES,
+			 mb0 + CLIB_CACHE_LINE_BYTES,
+			 b0->current_length - CLIB_CACHE_LINE_BYTES);
+
+	  /* trace */
+	  VLIB_BUFFER_TRACE_TRAJECTORY_INIT (b0);
+
+	  if (PREDICT_FALSE (n_trace > 0))
+	    {
+	      if (b0)
+		{
+		  memif_input_trace_t *tr;
+		  vlib_trace_buffer (vm, node, next0, b0,
+				     /* follow_chain */ 0);
+		  vlib_set_trace_count (vm, node, --n_trace);
+		  tr = vlib_add_trace (vm, node, b0, sizeof (*tr));
+		  tr->next_index = next0;
+		  tr->hw_if_index = mif->hw_if_index;
+		  tr->ring = rid;
+		}
+	    }
+
+
+	  /* redirect if feature path enabled */
+	  vnet_feature_start_device_input_x1 (mif->sw_if_index, &next0, b0);
+
+	  /* enqueue */
+	  vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
+					   n_left_to_next, bi0, next0);
+
+	  /* next packet */
+	  rd->last_head = (rd->last_head + 1) & mask;
+	  num_slots--;
+	  n_rx_packets++;
+	  n_rx_bytes += b0->current_length;
+	}
+      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
+    }
+  CLIB_MEMORY_STORE_BARRIER ();
+  ring->tail = head;
+
+  vlib_increment_combined_counter (vnm->interface_main.combined_sw_if_counters
+				   + VNET_INTERFACE_COUNTER_RX, cpu_index,
+				   mif->hw_if_index, n_rx_packets,
+				   n_rx_bytes);
+
+  return n_rx_packets;
+}
+
+static uword
+memif_input_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
+		vlib_frame_t * frame)
+{
+  u32 n_rx_packets = 0;
+  u32 cpu_index = os_get_cpu_number ();
+  memif_main_t *nm = &memif_main;
+  memif_if_t *mif;
+
+  /* *INDENT-OFF* */
+  pool_foreach (mif, nm->interfaces,
+    ({
+      if (mif->flags & MEMIF_IF_FLAG_ADMIN_UP &&
+	  mif->flags & MEMIF_IF_FLAG_CONNECTED &&
+	  (mif->if_index % nm->input_cpu_count) ==
+	  (cpu_index - nm->input_cpu_first_index))
+	{
+	  if (mif->flags & MEMIF_IF_FLAG_IS_SLAVE)
+	    n_rx_packets +=
+	      memif_device_input_inline (vm, node, frame, mif,
+					 MEMIF_RING_M2S);
+	  else
+	    n_rx_packets +=
+	      memif_device_input_inline (vm, node, frame, mif,
+					 MEMIF_RING_S2M);
+	}
+    }));
+  /* *INDENT-ON* */
+
+  return n_rx_packets;
+}
+
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (memif_input_node) = {
+  .function = memif_input_fn,
+  .name = "memif-input",
+  .sibling_of = "device-input",
+  .format_trace = format_memif_input_trace,
+  .type = VLIB_NODE_TYPE_INPUT,
+  .state = VLIB_NODE_STATE_INTERRUPT,
+  .n_errors = MEMIF_INPUT_N_ERROR,
+  .error_strings = memif_input_error_strings,
+};
+
+VLIB_NODE_FUNCTION_MULTIARCH (memif_input_node, memif_input_fn)
+/* *INDENT-ON* */
+
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */