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>

1 files changed, 383 insertions, 0 deletions

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:
+ */