memif: crash on recceiving a bad descriptor
[vpp.git] / src / plugins / memif / node.c
index 83f1277..5abd20a 100644 (file)
 #include <vlib/vlib.h>
 #include <vlib/unix/unix.h>
 #include <vnet/ethernet/ethernet.h>
-#include <vnet/devices/devices.h>
+#include <vnet/interface/rx_queue_funcs.h>
 #include <vnet/feature/feature.h>
 
 #include <memif/memif.h>
 #include <memif/private.h>
 
-#define foreach_memif_input_error \
-  _(NOT_IP, "not ip packet")
+#define MEMIF_IP_OFFSET 14
+
+#define foreach_memif_input_error                                             \
+  _ (BUFFER_ALLOC_FAIL, buffer_alloc, ERROR, "buffer allocation failed")      \
+  _ (BAD_DESC, bad_desc, ERROR, "bad descriptor")                             \
+  _ (NOT_IP, not_ip, INFO, "not ip packet")
 
 typedef enum
 {
-#define _(f,s) MEMIF_INPUT_ERROR_##f,
+#define _(f, n, s, d) MEMIF_INPUT_ERROR_##f,
   foreach_memif_input_error
 #undef _
     MEMIF_INPUT_N_ERROR,
 } memif_input_error_t;
 
-static __clib_unused char *memif_input_error_strings[] = {
-#define _(n,s) s,
+static vlib_error_desc_t memif_input_error_counters[] = {
+#define _(f, n, s, d) { #n, d, VL_COUNTER_SEVERITY_##s },
   foreach_memif_input_error
 #undef _
 };
@@ -69,535 +73,1025 @@ format_memif_input_trace (u8 * s, va_list * args)
   return s;
 }
 
+static_always_inline u32
+memif_next_from_ip_hdr (vlib_node_runtime_t * node, vlib_buffer_t * b)
+{
+  u8 *ptr = vlib_buffer_get_current (b);
+  u8 v = *ptr & 0xf0;
+
+  if (PREDICT_TRUE (v == 0x40))
+    return VNET_DEVICE_INPUT_NEXT_IP4_NCS_INPUT;
+  else if (PREDICT_TRUE (v == 0x60))
+    return VNET_DEVICE_INPUT_NEXT_IP6_INPUT;
+
+  b->error = node->errors[MEMIF_INPUT_ERROR_NOT_IP];
+  return VNET_DEVICE_INPUT_NEXT_DROP;
+}
+
 static_always_inline void
-memif_prefetch (vlib_main_t * vm, u32 bi)
+memif_trace_buffer (vlib_main_t * vm, vlib_node_runtime_t * node,
+                   memif_if_t * mif, vlib_buffer_t * b, u32 next, u16 qid,
+                   uword * n_tracep)
 {
-  vlib_buffer_t *b = vlib_get_buffer (vm, bi);
-  vlib_prefetch_buffer_header (b, STORE);
-  CLIB_PREFETCH (b->data, CLIB_CACHE_LINE_BYTES, STORE);
+  if (PREDICT_TRUE
+      (b != 0 && vlib_trace_buffer (vm, node, next, b, /* follow_chain */ 0)))
+    {
+      memif_input_trace_t *tr;
+      vlib_set_trace_count (vm, node, --(*n_tracep));
+      tr = vlib_add_trace (vm, node, b, sizeof (*tr));
+      tr->next_index = next;
+      tr->hw_if_index = mif->hw_if_index;
+      tr->ring = qid;
+    }
 }
 
 static_always_inline void
-memif_buffer_add_to_chain (vlib_main_t * vm, u32 bi, u32 first_bi,
-                          u32 prev_bi)
+memif_add_copy_op (memif_per_thread_data_t * ptd, void *data, u32 len,
+                  u16 buffer_offset, u16 buffer_vec_index)
 {
-  vlib_buffer_t *b = vlib_get_buffer (vm, bi);
-  vlib_buffer_t *first_b = vlib_get_buffer (vm, first_bi);
-  vlib_buffer_t *prev_b = vlib_get_buffer (vm, prev_bi);
+  memif_copy_op_t *co;
+  vec_add2_aligned (ptd->copy_ops, co, 1, CLIB_CACHE_LINE_BYTES);
+  co->data = data;
+  co->data_len = len;
+  co->buffer_offset = buffer_offset;
+  co->buffer_vec_index = buffer_vec_index;
+}
 
-  /* update first buffer */
-  first_b->total_length_not_including_first_buffer += b->current_length;
+static_always_inline void
+memif_add_to_chain (vlib_main_t * vm, vlib_buffer_t * b, u32 * buffers,
+                   u32 buffer_size)
+{
+  vlib_buffer_t *seg = b;
+  i32 bytes_left = b->current_length - buffer_size + b->current_data;
 
-  /* update previous buffer */
-  prev_b->next_buffer = bi;
-  prev_b->flags |= VLIB_BUFFER_NEXT_PRESENT;
+  if (PREDICT_TRUE (bytes_left <= 0))
+    return;
 
-  /* update current buffer */
-  b->next_buffer = 0;
+  b->current_length -= bytes_left;
+  b->total_length_not_including_first_buffer = bytes_left;
+
+  while (bytes_left)
+    {
+      seg->flags |= VLIB_BUFFER_NEXT_PRESENT;
+      seg->next_buffer = buffers[0];
+      seg = vlib_get_buffer (vm, buffers[0]);
+      buffers++;
+      seg->current_data = 0;
+      seg->current_length = clib_min (buffer_size, bytes_left);
+      bytes_left -= seg->current_length;
+    }
 }
 
-/**
- * @brief Copy buffer from rx ring
- *
- * @param * vm (in)
- * @param * mif (in) pointer to memif interface
- * @param * ring (in) pointer to memif ring
- * @param * rd (in) pointer to ring data
- * @param ring_size (in) ring size
- * @param * n_free_bufs (in/out) the number of free vlib buffers available
- * @param ** first_b (out) the first vlib buffer pointer
- * @param * first_bi (out) the first vlib buffer index
- * @param * bi (in/out) the current buffer index
- * #param * num_slots (in/out) the number of descriptors available to read
- *
- * @return total bytes read from rx ring also written to vlib buffers
- */
-static_always_inline uword
-memif_copy_buffer_from_rx_ring (vlib_main_t * vm, memif_if_t * mif,
-                               memif_ring_t * ring, memif_queue_t * mq,
-                               u16 ring_size, u32 n_buffer_bytes,
-                               u32 * n_free_bufs, vlib_buffer_t ** first_b,
-                               u32 * first_bi, u32 * bi, u16 * num_slots)
+static_always_inline u16
+memif_parse_desc (memif_per_thread_data_t *ptd, memif_if_t *mif,
+                 memif_queue_t *mq, u16 next, u16 n_avail)
 {
-  memif_main_t *nm = &memif_main;
-  u32 thread_index = vlib_get_thread_index ();
-  u32 total_bytes = 0, offset = 0;
-  u32 data_len;
-  u32 bytes_to_copy;
-  void *mb;
-  vlib_buffer_t *b;
-  u16 mask = ring_size - 1;
-  u32 prev_bi;
-  u16 last_head;
-
-  while (*num_slots)
+  memif_ring_t *ring = mq->ring;
+  memif_desc_t *descs = ring->desc;
+  void **desc_data = ptd->desc_data;
+  u16 *desc_len = ptd->desc_len;
+  memif_desc_status_t *desc_status = ptd->desc_status;
+  u16 n_desc = 0, n_pkts = 0;
+  u32 i = 0;
+  u16 mask = pow2_mask (mq->log2_ring_size);
+  memif_desc_t *d = 0;
+  u32 slot = next;
+
+  while (i < n_avail)
     {
-      data_len = ring->desc[mq->last_head & mask].length;
-      while (data_len && (*n_free_bufs))
+      u8 flags;
+      d = descs + (slot++ & mask);
+      desc_data[i] = (void *) ((u64) d->region << 32 | d->offset);
+      desc_len[i] = d->length;
+      desc_status[i].as_u8 = flags = d->flags;
+      i++;
+      if (PREDICT_FALSE ((flags & MEMIF_DESC_FLAG_NEXT)) == 0)
        {
-         /* get empty buffer */
-         u32 last_buf = vec_len (nm->rx_buffers[thread_index]) - 1;
-         prev_bi = *bi;
-         *bi = nm->rx_buffers[thread_index][last_buf];
-         b = vlib_get_buffer (vm, *bi);
-         /* Clear the error first to ensure following node forget setting it */
-         /* It will cause null-node error counter increasement instead of potential crash */
-         b->error = 0x0;
-         _vec_len (nm->rx_buffers[thread_index]) = last_buf;
-         (*n_free_bufs)--;
-         if (PREDICT_FALSE (*n_free_bufs == 0))
-           {
-             *n_free_bufs +=
-               vlib_buffer_alloc (vm,
-                                  &nm->rx_buffers[thread_index]
-                                  [*n_free_bufs], ring_size);
-             _vec_len (nm->rx_buffers[thread_index]) = *n_free_bufs;
-           }
+         n_desc = i;
+         if (++n_pkts == MEMIF_RX_VECTOR_SZ)
+           goto frame_full;
+       }
+    }
+frame_full:
 
-         if (last_buf > 4)
-           {
-             memif_prefetch (vm, nm->rx_buffers[thread_index][last_buf - 2]);
-             memif_prefetch (vm, nm->rx_buffers[thread_index][last_buf - 3]);
-           }
+  /* done */
+  ptd->n_packets = n_pkts;
+  return n_desc;
+}
 
-         /* copy buffer */
-         bytes_to_copy =
-           data_len > n_buffer_bytes ? n_buffer_bytes : data_len;
-         b->current_data = 0;
-         mb = memif_get_buffer (mif, ring, mq->last_head & mask);
-         clib_memcpy (vlib_buffer_get_current (b), mb + offset,
-                      CLIB_CACHE_LINE_BYTES);
-         if (bytes_to_copy > CLIB_CACHE_LINE_BYTES)
-           clib_memcpy (vlib_buffer_get_current (b) + CLIB_CACHE_LINE_BYTES,
-                        mb + CLIB_CACHE_LINE_BYTES + offset,
-                        bytes_to_copy - CLIB_CACHE_LINE_BYTES);
-
-         /* fill buffer header */
-         b->current_length = bytes_to_copy;
-
-         if (total_bytes == 0)
-           {
-             /* fill buffer metadata */
-             b->total_length_not_including_first_buffer = 0;
-             b->flags = VLIB_BUFFER_TOTAL_LENGTH_VALID;
-             vnet_buffer (b)->sw_if_index[VLIB_RX] = mif->sw_if_index;
-             vnet_buffer (b)->sw_if_index[VLIB_TX] = (u32) ~ 0;
-             *first_bi = *bi;
-             *first_b = vlib_get_buffer (vm, *first_bi);
-           }
-         else
-           memif_buffer_add_to_chain (vm, *bi, *first_bi, prev_bi);
+static_always_inline void
+memif_desc_status_set_err (memif_desc_status_t *p,
+                          memif_desc_status_err_code_t e)
+{
+  memif_desc_status_t s = { .err = 1, .err_code = e };
+  p->as_u8 |= s.as_u8;
+}
+
+static_always_inline void
+memif_validate_desc_data (memif_per_thread_data_t *ptd, memif_if_t *mif,
+                         u16 n_desc, int is_ethernet)
+{
+  void **desc_data = ptd->desc_data;
+  u16 *desc_len = ptd->desc_len;
+  memif_desc_status_t *desc_status = ptd->desc_status;
+  u16 n_regions = vec_len (mif->regions);
+  u32 n_rx_bytes = 0;
+  u16 max_len = 0;
+  u8 xor_status = 0;
 
-         offset += bytes_to_copy;
-         total_bytes += bytes_to_copy;
-         data_len -= bytes_to_copy;
+  for (u32 i = 0; i < n_desc; i++)
+    {
+      u16 region = ((u64) desc_data[i]) >> 32;
+      u32 offset = (u64) desc_data[i];
+      u16 len = desc_len[i];
+      memif_region_t *r = mif->regions + region;
+
+      if (region >= n_regions)
+       memif_desc_status_set_err (desc_status + i,
+                                  MEMIF_DESC_STATUS_ERR_BAD_REGION);
+      else if (offset + len > r->region_size)
+       memif_desc_status_set_err (desc_status + i,
+                                  MEMIF_DESC_STATUS_ERR_REGION_OVERRUN);
+      else if (is_ethernet && len > ETHERNET_MAX_PACKET_BYTES)
+       memif_desc_status_set_err (desc_status + i,
+                                  MEMIF_DESC_STATUS_ERR_DATA_TOO_BIG);
+      else if (len == 0)
+       memif_desc_status_set_err (desc_status + i,
+                                  MEMIF_DESC_STATUS_ERR_ZERO_LENGTH);
+      else
+       {
+         desc_data[i] = r->shm + offset;
+         if (len > max_len)
+           max_len = len;
+         n_rx_bytes += len;
        }
-      last_head = mq->last_head;
-      /* Advance to next descriptor */
-      mq->last_head++;
-      offset = 0;
-      (*num_slots)--;
-      if ((ring->desc[last_head & mask].flags & MEMIF_DESC_FLAG_NEXT) == 0)
-       break;
+      xor_status |= desc_status[i].as_u8;
     }
 
-  return (total_bytes);
+  ptd->max_desc_len = max_len;
+  ptd->xor_status = xor_status;
+  ptd->n_rx_bytes = n_rx_bytes;
 }
 
-
 static_always_inline u32
-memif_next_from_ip_hdr (vlib_node_runtime_t * node, vlib_buffer_t * b)
+memif_process_desc (vlib_main_t *vm, vlib_node_runtime_t *node,
+                   memif_per_thread_data_t *ptd, memif_if_t *mif)
 {
-  u8 *ptr = vlib_buffer_get_current (b);
-  u8 v = *ptr & 0xf0;
+  u16 buffer_size = vlib_buffer_get_default_data_size (vm);
+  int is_ip = mif->mode == MEMIF_INTERFACE_MODE_IP;
+  i16 start_offset = (is_ip) ? MEMIF_IP_OFFSET : 0;
+  memif_packet_op_t *po = ptd->packet_ops;
+  void **desc_data = ptd->desc_data;
+  u16 *desc_len = ptd->desc_len;
+  memif_desc_status_t *desc_status = ptd->desc_status;
+  u32 n_buffers = 0;
+  u32 n_left = ptd->n_packets;
+  u32 packet_len;
+  int i = -1;
+
+  /* construct copy and packet vector out of ring slots */
+  while (n_left)
+    {
+      u32 dst_off, src_off, n_bytes_left;
+      void *mb0;
+      po->first_buffer_vec_index = n_buffers++;
 
-  if (PREDICT_TRUE (v == 0x40))
-    return VNET_DEVICE_INPUT_NEXT_IP4_NCS_INPUT;
-  else if (PREDICT_TRUE (v == 0x60))
-    return VNET_DEVICE_INPUT_NEXT_IP6_INPUT;
+      packet_len = 0;
+      src_off = 0;
+      dst_off = start_offset;
 
-  b->error = node->errors[MEMIF_INPUT_ERROR_NOT_IP];
-  return VNET_DEVICE_INPUT_NEXT_DROP;
+    next_slot:
+      i++; /* next descriptor */
+      n_bytes_left = desc_len[i];
+
+      packet_len += n_bytes_left;
+      mb0 = desc_data[i];
+
+      if (PREDICT_FALSE (desc_status[i].err))
+       vlib_error_count (vm, node->node_index, MEMIF_INPUT_ERROR_BAD_DESC, 1);
+      else
+       do
+         {
+           u32 dst_free = buffer_size - dst_off;
+           if (dst_free == 0)
+             {
+               dst_off = 0;
+               dst_free = buffer_size;
+               n_buffers++;
+             }
+           u32 bytes_to_copy = clib_min (dst_free, n_bytes_left);
+           memif_add_copy_op (ptd, mb0 + src_off, bytes_to_copy, dst_off,
+                              n_buffers - 1);
+           n_bytes_left -= bytes_to_copy;
+           src_off += bytes_to_copy;
+           dst_off += bytes_to_copy;
+         }
+       while (PREDICT_FALSE (n_bytes_left));
+
+      if (desc_status[i].next)
+       {
+         src_off = 0;
+         goto next_slot;
+       }
+
+      /* update packet op */
+      po->packet_len = packet_len;
+      po++;
+
+      /* next packet */
+      n_left--;
+    }
+  return n_buffers;
+}
+static_always_inline void
+memif_fill_buffer_mdata_simple (vlib_node_runtime_t *node,
+                               memif_per_thread_data_t *ptd,
+                               vlib_buffer_t **b, u16 *next, int is_ip)
+{
+  vlib_buffer_t bt;
+  u16 *dl = ptd->desc_len;
+  /* process buffer metadata */
+
+  u32 n_left = ptd->n_packets;
+
+  /* copy template into local variable - will save per packet load */
+  vlib_buffer_copy_template (&bt, &ptd->buffer_template);
+
+  while (n_left >= 8)
+    {
+      vlib_prefetch_buffer_header (b[4], STORE);
+      vlib_prefetch_buffer_header (b[5], STORE);
+      vlib_prefetch_buffer_header (b[6], STORE);
+      vlib_prefetch_buffer_header (b[7], STORE);
+
+      vlib_buffer_copy_template (b[0], &bt);
+      vlib_buffer_copy_template (b[1], &bt);
+      vlib_buffer_copy_template (b[2], &bt);
+      vlib_buffer_copy_template (b[3], &bt);
+
+      b[0]->current_length = dl[0];
+      b[1]->current_length = dl[1];
+      b[2]->current_length = dl[2];
+      b[3]->current_length = dl[3];
+
+      if (is_ip)
+       {
+         next[0] = memif_next_from_ip_hdr (node, b[0]);
+         next[1] = memif_next_from_ip_hdr (node, b[1]);
+         next[2] = memif_next_from_ip_hdr (node, b[2]);
+         next[3] = memif_next_from_ip_hdr (node, b[3]);
+       }
+
+      /* next */
+      n_left -= 4;
+      b += 4;
+      dl += 4;
+      next += 4;
+    }
+
+  while (n_left)
+    {
+      /* enqueue buffer */
+      vlib_buffer_copy_template (b[0], &bt);
+      b[0]->current_length = dl[0];
+      if (is_ip)
+       next[0] = memif_next_from_ip_hdr (node, b[0]);
+
+      /* next */
+      n_left -= 1;
+      b += 1;
+      dl += 1;
+      next += 1;
+    }
+}
+
+static_always_inline void
+memif_fill_buffer_mdata (vlib_main_t *vm, vlib_node_runtime_t *node,
+                        memif_per_thread_data_t *ptd, memif_if_t *mif,
+                        u32 *bi, u16 *next, int is_ip)
+{
+  u16 buffer_size = vlib_buffer_get_default_data_size (vm);
+  vlib_buffer_t *b0, *b1, *b2, *b3, bt;
+  memif_packet_op_t *po;
+  /* process buffer metadata */
+
+  u32 n_from = ptd->n_packets;
+  po = ptd->packet_ops;
+
+  /* copy template into local variable - will save per packet load */
+  vlib_buffer_copy_template (&bt, &ptd->buffer_template);
+
+  while (n_from >= 8)
+    {
+      b0 = vlib_get_buffer (vm, ptd->buffers[po[4].first_buffer_vec_index]);
+      b1 = vlib_get_buffer (vm, ptd->buffers[po[5].first_buffer_vec_index]);
+      b2 = vlib_get_buffer (vm, ptd->buffers[po[6].first_buffer_vec_index]);
+      b3 = vlib_get_buffer (vm, ptd->buffers[po[7].first_buffer_vec_index]);
+
+      vlib_prefetch_buffer_header (b0, STORE);
+      vlib_prefetch_buffer_header (b1, STORE);
+      vlib_prefetch_buffer_header (b2, STORE);
+      vlib_prefetch_buffer_header (b3, STORE);
+
+      /* enqueue buffer */
+      u32 fbvi[4];
+      fbvi[0] = po[0].first_buffer_vec_index;
+      fbvi[1] = po[1].first_buffer_vec_index;
+      fbvi[2] = po[2].first_buffer_vec_index;
+      fbvi[3] = po[3].first_buffer_vec_index;
+
+      bi[0] = ptd->buffers[fbvi[0]];
+      bi[1] = ptd->buffers[fbvi[1]];
+      bi[2] = ptd->buffers[fbvi[2]];
+      bi[3] = ptd->buffers[fbvi[3]];
+
+      b0 = vlib_get_buffer (vm, bi[0]);
+      b1 = vlib_get_buffer (vm, bi[1]);
+      b2 = vlib_get_buffer (vm, bi[2]);
+      b3 = vlib_get_buffer (vm, bi[3]);
+
+      vlib_buffer_copy_template (b0, &bt);
+      vlib_buffer_copy_template (b1, &bt);
+      vlib_buffer_copy_template (b2, &bt);
+      vlib_buffer_copy_template (b3, &bt);
+
+      b0->current_length = po[0].packet_len;
+      b1->current_length = po[1].packet_len;
+      b2->current_length = po[2].packet_len;
+      b3->current_length = po[3].packet_len;
+
+      memif_add_to_chain (vm, b0, ptd->buffers + fbvi[0] + 1, buffer_size);
+      memif_add_to_chain (vm, b1, ptd->buffers + fbvi[1] + 1, buffer_size);
+      memif_add_to_chain (vm, b2, ptd->buffers + fbvi[2] + 1, buffer_size);
+      memif_add_to_chain (vm, b3, ptd->buffers + fbvi[3] + 1, buffer_size);
+
+      if (is_ip)
+       {
+         next[0] = memif_next_from_ip_hdr (node, b0);
+         next[1] = memif_next_from_ip_hdr (node, b1);
+         next[2] = memif_next_from_ip_hdr (node, b2);
+         next[3] = memif_next_from_ip_hdr (node, b3);
+       }
+
+      /* next */
+      n_from -= 4;
+      po += 4;
+      bi += 4;
+      next += 4;
+    }
+  while (n_from)
+    {
+      u32 fbvi[1];
+      /* enqueue buffer */
+      fbvi[0] = po[0].first_buffer_vec_index;
+      bi[0] = ptd->buffers[fbvi[0]];
+      b0 = vlib_get_buffer (vm, bi[0]);
+      vlib_buffer_copy_template (b0, &bt);
+      b0->current_length = po->packet_len;
+
+      memif_add_to_chain (vm, b0, ptd->buffers + fbvi[0] + 1, buffer_size);
+
+      if (is_ip)
+       next[0] = memif_next_from_ip_hdr (node, b0);
+
+      /* next */
+      n_from -= 1;
+      po += 1;
+      bi += 1;
+      next += 1;
+    }
 }
 
 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, u16 qid,
+memif_device_input_inline (vlib_main_t *vm, vlib_node_runtime_t *node,
+                          memif_if_t *mif, memif_ring_type_t type, u16 qid,
                           memif_interface_mode_t mode)
 {
   vnet_main_t *vnm = vnet_get_main ();
+  memif_main_t *mm = &memif_main;
   memif_ring_t *ring;
   memif_queue_t *mq;
-  u16 head;
-  u32 next_index;
-  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 b0_total, b1_total;
-  u32 thread_index = vlib_get_thread_index ();
-  u16 ring_size, mask, num_slots;
-  u32 n_buffer_bytes = vlib_buffer_free_list_buffer_size (vm,
-                                                         VLIB_BUFFER_DEFAULT_FREE_LIST_INDEX);
+  u16 buffer_size = vlib_buffer_get_default_data_size (vm);
+  uword n_trace;
+  u16 nexts[MEMIF_RX_VECTOR_SZ], *next = nexts;
+  u32 _to_next_bufs[MEMIF_RX_VECTOR_SZ], *to_next_bufs = _to_next_bufs, *bi;
+  u32 n_left_to_next;
+  u32 next_index = VNET_DEVICE_INPUT_NEXT_ETHERNET_INPUT;
+  vlib_buffer_t *buffer_ptrs[MEMIF_RX_VECTOR_SZ];
+  u32 thread_index = vm->thread_index;
+  memif_per_thread_data_t *ptd =
+    vec_elt_at_index (mm->per_thread_data, thread_index);
+  u16 cur_slot, ring_size, n_slots, mask;
+  u16 n_buffers, n_alloc, n_desc;
+  i16 start_offset;
+  memif_copy_op_t *co;
+  int is_slave = (mif->flags & MEMIF_IF_FLAG_IS_SLAVE) != 0;
+  int is_simple = 1;
+  int i;
 
   mq = vec_elt_at_index (mif->rx_queues, qid);
   ring = mq->ring;
   ring_size = 1 << mq->log2_ring_size;
   mask = ring_size - 1;
 
-  if (mode == MEMIF_INTERFACE_MODE_IP)
+  start_offset = (mode == MEMIF_INTERFACE_MODE_IP) ? MEMIF_IP_OFFSET : 0;
+
+  if (is_slave)
     {
-      next_index = VNET_DEVICE_INPUT_NEXT_IP6_INPUT;
+      cur_slot = mq->last_tail;
+      n_slots = __atomic_load_n (&ring->tail, __ATOMIC_ACQUIRE) - cur_slot;
     }
   else
     {
-      next_index = VNET_DEVICE_INPUT_NEXT_ETHERNET_INPUT;
+      cur_slot = mq->last_head;
+      n_slots = __atomic_load_n (&ring->head, __ATOMIC_ACQUIRE) - cur_slot;
     }
 
-  n_free_bufs = vec_len (nm->rx_buffers[thread_index]);
-  if (PREDICT_FALSE (n_free_bufs < ring_size))
+  if (n_slots == 0)
+    goto refill;
+
+  n_desc = memif_parse_desc (ptd, mif, mq, cur_slot, n_slots);
+
+  if (n_desc != ptd->n_packets)
+    is_simple = 0;
+
+  cur_slot += n_desc;
+
+  if (mif->mode == MEMIF_INTERFACE_MODE_ETHERNET)
+    memif_validate_desc_data (ptd, mif, n_desc, /* is_ethernet */ 1);
+  else
+    memif_validate_desc_data (ptd, mif, n_desc, /* is_ethernet */ 0);
+
+  if (ptd->max_desc_len > buffer_size - start_offset)
+    is_simple = 0;
+
+  if (ptd->xor_status != 0)
+    is_simple = 0;
+
+  if (is_simple)
+    n_buffers = ptd->n_packets;
+  else
+    n_buffers = memif_process_desc (vm, node, ptd, mif);
+
+  /* allocate free buffers */
+  vec_validate_aligned (ptd->buffers, n_buffers - 1, CLIB_CACHE_LINE_BYTES);
+  n_alloc = vlib_buffer_alloc_from_pool (vm, ptd->buffers, n_buffers,
+                                        mq->buffer_pool_index);
+  if (PREDICT_FALSE (n_alloc != n_buffers))
     {
-      vec_validate (nm->rx_buffers[thread_index],
-                   ring_size + n_free_bufs - 1);
-      n_free_bufs +=
-       vlib_buffer_alloc (vm, &nm->rx_buffers[thread_index][n_free_bufs],
-                          ring_size);
-      _vec_len (nm->rx_buffers[thread_index]) = n_free_bufs;
+      if (n_alloc)
+       vlib_buffer_free (vm, ptd->buffers, n_alloc);
+      vlib_error_count (vm, node->node_index,
+                       MEMIF_INPUT_ERROR_BUFFER_ALLOC_FAIL, 1);
+      goto refill;
     }
 
-  head = ring->head;
-  mq->last_head = ring->tail;
-  if (head == mq->last_head)
-    return 0;
+  /* copy data */
+  if (is_simple)
+    {
+      int n_pkts = ptd->n_packets;
+      void **desc_data = ptd->desc_data;
+      u16 *desc_len = ptd->desc_len;
 
-  num_slots = head - mq->last_head;
+      vlib_get_buffers (vm, ptd->buffers, buffer_ptrs, n_buffers);
 
-  while (num_slots)
+      for (i = 0; i + 8 < n_pkts; i++)
+       {
+         clib_prefetch_load (desc_data[i + 8]);
+         clib_prefetch_store (buffer_ptrs[i + 8]->data);
+         clib_memcpy_fast (buffer_ptrs[i]->data + start_offset, desc_data[i],
+                           desc_len[i]);
+       }
+      for (; i < n_pkts; i++)
+       clib_memcpy_fast (buffer_ptrs[i]->data + start_offset, desc_data[i],
+                         desc_len[i]);
+    }
+  else
     {
-      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);
+      vlib_buffer_t *b;
+      u32 n_pkts = vec_len (ptd->copy_ops);
+      co = ptd->copy_ops;
 
-      while (num_slots > 11 && n_left_to_next > 2)
+      for (i = 0; i + 8 < n_pkts; i++)
        {
-         CLIB_PREFETCH (memif_get_buffer
-                        (mif, ring, (mq->last_head + 2) & mask),
-                        CLIB_CACHE_LINE_BYTES, LOAD);
-         CLIB_PREFETCH (memif_get_buffer
-                        (mif, ring, (mq->last_head + 3) & mask),
-                        CLIB_CACHE_LINE_BYTES, LOAD);
-         CLIB_PREFETCH (&ring->desc[(mq->last_head + 4) & mask],
-                        CLIB_CACHE_LINE_BYTES, LOAD);
-         CLIB_PREFETCH (&ring->desc[(mq->last_head + 5) & mask],
-                        CLIB_CACHE_LINE_BYTES, LOAD);
-
-         vlib_buffer_t *first_b0 = 0;
-         u32 bi0 = 0, first_bi0 = 0;
-         b0_total = memif_copy_buffer_from_rx_ring (vm, mif, ring, mq,
-                                                    ring_size,
-                                                    n_buffer_bytes,
-                                                    &n_free_bufs, &first_b0,
-                                                    &first_bi0, &bi0,
-                                                    &num_slots);
-
-         vlib_buffer_t *first_b1 = 0;
-         u32 bi1 = 0, first_bi1 = 0;
-         b1_total = memif_copy_buffer_from_rx_ring (vm, mif, ring, mq,
-                                                    ring_size,
-                                                    n_buffer_bytes,
-                                                    &n_free_bufs, &first_b1,
-                                                    &first_bi1, &bi1,
-                                                    &num_slots);
-
-         if (PREDICT_FALSE (!first_bi0 || !first_bi1))
-           {
-             goto _invalid_pkt01;
-           }
-         /* enqueue buffer */
-         to_next[0] = first_bi0;
-         to_next[1] = first_bi1;
-         to_next += 2;
-         n_left_to_next -= 2;
+         clib_prefetch_load (co[i + 8].data);
+         b = vlib_get_buffer (vm, ptd->buffers[co[i].buffer_vec_index]);
+         clib_memcpy_fast (b->data + co[i].buffer_offset, co[i].data,
+                           co[i].data_len);
+       }
+      for (; i < n_pkts; i++)
+       {
+         b = vlib_get_buffer (vm, ptd->buffers[co[i].buffer_vec_index]);
+         clib_memcpy_fast (b->data + co[i].buffer_offset, co[i].data,
+                           co[i].data_len);
+       }
+    }
 
+  /* release slots from the ring */
+  if (type == MEMIF_RING_S2M)
+    {
+      __atomic_store_n (&ring->tail, cur_slot, __ATOMIC_RELEASE);
+      mq->last_head = cur_slot;
+    }
+  else
+    {
+      mq->last_tail = cur_slot;
+    }
 
-         if (mode == MEMIF_INTERFACE_MODE_IP)
-           {
-             next0 = memif_next_from_ip_hdr (node, first_b0);
-             next1 = memif_next_from_ip_hdr (node, first_b1);
-           }
-         else if (mode == MEMIF_INTERFACE_MODE_ETHERNET)
-           {
-             if (PREDICT_FALSE (mif->per_interface_next_index != ~0))
-               next0 = next1 = mif->per_interface_next_index;
-             else
-               /* redirect if feature path
-                * enabled */
-               vnet_feature_start_device_input_x2 (mif->sw_if_index,
-                                                   &next0, &next1,
-                                                   first_b0, first_b1);
-           }
+  /* prepare buffer template and next indices */
+  vnet_buffer (&ptd->buffer_template)->sw_if_index[VLIB_RX] = mif->sw_if_index;
+  vnet_buffer (&ptd->buffer_template)->feature_arc_index = 0;
+  ptd->buffer_template.current_data = start_offset;
+  ptd->buffer_template.current_config_index = 0;
+  ptd->buffer_template.buffer_pool_index = mq->buffer_pool_index;
+  ptd->buffer_template.ref_count = 1;
 
-         /* trace */
-         VLIB_BUFFER_TRACE_TRAJECTORY_INIT (first_b0);
-         VLIB_BUFFER_TRACE_TRAJECTORY_INIT (first_b1);
+  if (mode == MEMIF_INTERFACE_MODE_ETHERNET)
+    {
+      next_index = VNET_DEVICE_INPUT_NEXT_ETHERNET_INPUT;
+      if (mif->per_interface_next_index != ~0)
+       next_index = mif->per_interface_next_index;
+      else
+       vnet_feature_start_device_input_x1 (mif->sw_if_index, &next_index,
+                                           &ptd->buffer_template);
+
+      vlib_get_new_next_frame (vm, node, next_index, to_next_bufs,
+                              n_left_to_next);
+      if (PREDICT_TRUE (next_index == VNET_DEVICE_INPUT_NEXT_ETHERNET_INPUT))
+       {
+         vlib_next_frame_t *nf;
+         vlib_frame_t *f;
+         ethernet_input_frame_t *ef;
+         nf = vlib_node_runtime_get_next_frame (vm, node, next_index);
+         f = vlib_get_frame (vm, nf->frame);
+         f->flags = ETH_INPUT_FRAME_F_SINGLE_SW_IF_IDX;
+
+         ef = vlib_frame_scalar_args (f);
+         ef->sw_if_index = mif->sw_if_index;
+         ef->hw_if_index = mif->hw_if_index;
+         vlib_frame_no_append (f);
+       }
+    }
 
-         if (PREDICT_FALSE (n_trace > 0))
+  if (is_simple)
+    {
+      vlib_buffer_copy_indices (to_next_bufs, ptd->buffers, ptd->n_packets);
+      if (mode == MEMIF_INTERFACE_MODE_IP)
+       memif_fill_buffer_mdata_simple (node, ptd, buffer_ptrs, nexts, 1);
+      else
+       memif_fill_buffer_mdata_simple (node, ptd, buffer_ptrs, nexts, 0);
+    }
+  else
+    {
+      if (mode == MEMIF_INTERFACE_MODE_IP)
+       memif_fill_buffer_mdata (vm, node, ptd, mif, to_next_bufs, nexts, 1);
+      else
+       memif_fill_buffer_mdata (vm, node, ptd, mif, to_next_bufs, nexts, 0);
+    }
+
+  /* packet trace if enabled */
+  if (PREDICT_FALSE ((n_trace = vlib_get_trace_count (vm, node))))
+    {
+      u32 n_left = ptd->n_packets;
+      bi = to_next_bufs;
+      next = nexts;
+      u32 ni = next_index;
+      while (n_trace && n_left)
+       {
+         vlib_buffer_t *b;
+         memif_input_trace_t *tr;
+         if (mode != MEMIF_INTERFACE_MODE_ETHERNET)
+           ni = next[0];
+         b = vlib_get_buffer (vm, bi[0]);
+         if (PREDICT_TRUE
+             (vlib_trace_buffer (vm, node, ni, b, /* follow_chain */ 0)))
            {
-             /* b0 */
-             if (PREDICT_TRUE (first_b0 != 0))
-               {
-                 memif_input_trace_t *tr;
-                 vlib_trace_buffer (vm, node, next0, first_b0,
-                                    /* follow_chain */ 0);
-                 vlib_set_trace_count (vm, node, --n_trace);
-                 tr = vlib_add_trace (vm, node, first_b0, sizeof (*tr));
-                 tr->next_index = next0;
-                 tr->hw_if_index = mif->hw_if_index;
-                 tr->ring = qid;
-               }
-             if (n_trace)
-               {
-                 /* b1 */
-                 if (PREDICT_TRUE (first_b1 != 0))
-                   {
-                     memif_input_trace_t *tr;
-                     vlib_trace_buffer (vm, node, next1, first_b1,
-                                        /* follow_chain */ 0);
-                     vlib_set_trace_count (vm, node, --n_trace);
-                     tr = vlib_add_trace (vm, node, first_b1, sizeof (*tr));
-                     tr->next_index = next1;
-                     tr->hw_if_index = mif->hw_if_index;
-                     tr->ring = qid;
-                   }
-               }
+             tr = vlib_add_trace (vm, node, b, sizeof (*tr));
+             tr->next_index = ni;
+             tr->hw_if_index = mif->hw_if_index;
+             tr->ring = qid;
+             n_trace--;
            }
 
-         /* enqueue */
-         vlib_validate_buffer_enqueue_x2 (vm, node, next_index, to_next,
-                                          n_left_to_next, first_bi0,
-                                          first_bi1, next0, next1);
+         /* next */
+         n_left--;
+         bi++;
+         next++;
+       }
+      vlib_set_trace_count (vm, node, n_trace);
+    }
 
-         /* next packet */
-         n_rx_packets += 2;
-         n_rx_bytes += b0_total + b1_total;
+  if (mode == MEMIF_INTERFACE_MODE_ETHERNET)
+    {
+      n_left_to_next -= ptd->n_packets;
+      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
+    }
+  else
+    vlib_buffer_enqueue_to_next (vm, node, to_next_bufs, nexts,
+                                ptd->n_packets);
 
-         continue;
-       _invalid_pkt01:
-         if (!first_bi0 && !first_bi1)
-           {
-             continue;
-           }
-         if (first_bi1)
-           {
-             first_bi0 = first_bi1;
-             first_b0 = first_b1;
-             bi0 = bi1;
-             b0_total = b1_total;
-           }
+  vlib_increment_combined_counter (
+    vnm->interface_main.combined_sw_if_counters + VNET_INTERFACE_COUNTER_RX,
+    thread_index, mif->sw_if_index, ptd->n_packets, ptd->n_rx_bytes);
+
+  /* refill ring with empty buffers */
+refill:
+  vec_reset_length (ptd->buffers);
+  vec_reset_length (ptd->copy_ops);
+
+  if (type == MEMIF_RING_M2S)
+    {
+      u16 head = ring->head;
+      n_slots = ring_size - head + mq->last_tail;
+
+      while (n_slots--)
+       {
+         u16 s = head++ & mask;
+         memif_desc_t *d = &ring->desc[s];
+         d->length = mif->run.buffer_size;
+       }
+
+      __atomic_store_n (&ring->head, head, __ATOMIC_RELEASE);
+    }
+
+  return ptd->n_packets;
+}
+
+static_always_inline uword
+memif_device_input_zc_inline (vlib_main_t *vm, vlib_node_runtime_t *node,
+                             memif_if_t *mif, u16 qid,
+                             memif_interface_mode_t mode)
+{
+  vnet_main_t *vnm = vnet_get_main ();
+  memif_main_t *mm = &memif_main;
+  memif_ring_t *ring;
+  memif_queue_t *mq;
+  u32 next_index;
+  uword n_trace = vlib_get_trace_count (vm, node);
+  u32 n_rx_packets = 0, n_rx_bytes = 0;
+  u32 *to_next = 0, *buffers;
+  u32 bi0, bi1, bi2, bi3;
+  u16 slot, s0;
+  memif_desc_t *d0;
+  vlib_buffer_t *b0, *b1, *b2, *b3;
+  u32 thread_index = vm->thread_index;
+  memif_per_thread_data_t *ptd = vec_elt_at_index (mm->per_thread_data,
+                                                  thread_index);
+  u16 cur_slot, last_slot, ring_size, n_slots, mask, head;
+  i16 start_offset;
+  u64 offset;
+  u32 buffer_length;
+  u16 n_alloc, n_from;
+
+  mq = vec_elt_at_index (mif->rx_queues, qid);
+  ring = mq->ring;
+  ring_size = 1 << mq->log2_ring_size;
+  mask = ring_size - 1;
+
+  next_index = (mode == MEMIF_INTERFACE_MODE_IP) ?
+    VNET_DEVICE_INPUT_NEXT_IP6_INPUT : VNET_DEVICE_INPUT_NEXT_ETHERNET_INPUT;
+
+  /* asume that somebody will want to add ethernet header on the packet
+     so start with IP header at offset 14 */
+  start_offset = (mode == MEMIF_INTERFACE_MODE_IP) ? 14 : 0;
+  buffer_length = vlib_buffer_get_default_data_size (vm) - start_offset;
+
+  cur_slot = mq->last_tail;
+  last_slot = __atomic_load_n (&ring->tail, __ATOMIC_ACQUIRE);
+  if (cur_slot == last_slot)
+    goto refill;
+  n_slots = last_slot - cur_slot;
+
+  /* process ring slots */
+  vec_validate_aligned (ptd->buffers, MEMIF_RX_VECTOR_SZ,
+                       CLIB_CACHE_LINE_BYTES);
+  while (n_slots && n_rx_packets < MEMIF_RX_VECTOR_SZ)
+    {
+      vlib_buffer_t *hb;
+
+      s0 = cur_slot & mask;
+      bi0 = mq->buffers[s0];
+      ptd->buffers[n_rx_packets++] = bi0;
+
+      clib_prefetch_load (&ring->desc[(cur_slot + 8) & mask]);
+      d0 = &ring->desc[s0];
+      hb = b0 = vlib_get_buffer (vm, bi0);
+      b0->current_data = start_offset;
+      b0->current_length = d0->length;
+      n_rx_bytes += d0->length;
+
+      cur_slot++;
+      n_slots--;
+      if (PREDICT_FALSE ((d0->flags & MEMIF_DESC_FLAG_NEXT) && n_slots))
+       {
+         hb->flags |= VLIB_BUFFER_TOTAL_LENGTH_VALID;
+         hb->total_length_not_including_first_buffer = 0;
+       next_slot:
+         s0 = cur_slot & mask;
+         d0 = &ring->desc[s0];
+         bi0 = mq->buffers[s0];
+
+         /* previous buffer */
+         b0->next_buffer = bi0;
+         b0->flags |= VLIB_BUFFER_NEXT_PRESENT;
+
+         /* current buffer */
+         b0 = vlib_get_buffer (vm, bi0);
+         b0->current_data = start_offset;
+         b0->current_length = d0->length;
+         hb->total_length_not_including_first_buffer += d0->length;
+         n_rx_bytes += d0->length;
+
+         cur_slot++;
+         n_slots--;
+         if ((d0->flags & MEMIF_DESC_FLAG_NEXT) && n_slots)
+           goto next_slot;
+       }
+    }
+
+  /* release slots from the ring */
+  mq->last_tail = cur_slot;
+
+  n_from = n_rx_packets;
+  buffers = ptd->buffers;
+
+  while (n_from)
+    {
+      u32 n_left_to_next;
+      u32 next0, next1, next2, next3;
+
+      vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
+      while (n_from >= 8 && n_left_to_next >= 4)
+       {
+         b0 = vlib_get_buffer (vm, buffers[4]);
+         b1 = vlib_get_buffer (vm, buffers[5]);
+         b2 = vlib_get_buffer (vm, buffers[6]);
+         b3 = vlib_get_buffer (vm, buffers[7]);
+         vlib_prefetch_buffer_header (b0, STORE);
+         vlib_prefetch_buffer_header (b1, STORE);
+         vlib_prefetch_buffer_header (b2, STORE);
+         vlib_prefetch_buffer_header (b3, STORE);
+
+         /* enqueue buffer */
+         to_next[0] = bi0 = buffers[0];
+         to_next[1] = bi1 = buffers[1];
+         to_next[2] = bi2 = buffers[2];
+         to_next[3] = bi3 = buffers[3];
+         to_next += 4;
+         n_left_to_next -= 4;
+         buffers += 4;
+
+         b0 = vlib_get_buffer (vm, bi0);
+         b1 = vlib_get_buffer (vm, bi1);
+         b2 = vlib_get_buffer (vm, bi2);
+         b3 = vlib_get_buffer (vm, bi3);
+
+         vnet_buffer (b0)->sw_if_index[VLIB_RX] = mif->sw_if_index;
+         vnet_buffer (b0)->sw_if_index[VLIB_TX] = ~0;
+         vnet_buffer (b1)->sw_if_index[VLIB_RX] = mif->sw_if_index;
+         vnet_buffer (b1)->sw_if_index[VLIB_TX] = ~0;
+         vnet_buffer (b2)->sw_if_index[VLIB_RX] = mif->sw_if_index;
+         vnet_buffer (b2)->sw_if_index[VLIB_TX] = ~0;
+         vnet_buffer (b3)->sw_if_index[VLIB_RX] = mif->sw_if_index;
+         vnet_buffer (b3)->sw_if_index[VLIB_TX] = ~0;
 
          if (mode == MEMIF_INTERFACE_MODE_IP)
            {
-             next0 = memif_next_from_ip_hdr (node, first_b0);
+             next0 = memif_next_from_ip_hdr (node, b0);
+             next1 = memif_next_from_ip_hdr (node, b1);
+             next2 = memif_next_from_ip_hdr (node, b2);
+             next3 = memif_next_from_ip_hdr (node, b3);
            }
          else if (mode == MEMIF_INTERFACE_MODE_ETHERNET)
            {
              if (PREDICT_FALSE (mif->per_interface_next_index != ~0))
-               next0 = mif->per_interface_next_index;
+               {
+                 next0 = mif->per_interface_next_index;
+                 next1 = mif->per_interface_next_index;
+                 next2 = mif->per_interface_next_index;
+                 next3 = mif->per_interface_next_index;
+               }
              else
-               /* redirect if feature path
-                * enabled */
-               vnet_feature_start_device_input_x1 (mif->sw_if_index, &next0,
-                                                   first_b0);
+               {
+                 next0 = next1 = next2 = next3 = next_index;
+                 /* redirect if feature path enabled */
+                 vnet_feature_start_device_input_x1 (mif->sw_if_index,
+                                                     &next0, b0);
+                 vnet_feature_start_device_input_x1 (mif->sw_if_index,
+                                                     &next1, b1);
+                 vnet_feature_start_device_input_x1 (mif->sw_if_index,
+                                                     &next2, b2);
+                 vnet_feature_start_device_input_x1 (mif->sw_if_index,
+                                                     &next3, b3);
+               }
            }
 
          /* trace */
-         VLIB_BUFFER_TRACE_TRAJECTORY_INIT (first_b0);
-
          if (PREDICT_FALSE (n_trace > 0))
            {
-             if (PREDICT_TRUE (first_b0 != 0))
-               {
-                 memif_input_trace_t *tr;
-                 vlib_trace_buffer (vm, node, next0, first_b0,
-                                    /* follow_chain */ 0);
-                 vlib_set_trace_count (vm, node, --n_trace);
-                 tr = vlib_add_trace (vm, node, first_b0, sizeof (*tr));
-                 tr->next_index = next0;
-                 tr->hw_if_index = mif->hw_if_index;
-                 tr->ring = qid;
-               }
+             memif_trace_buffer (vm, node, mif, b0, next0, qid, &n_trace);
+             if (PREDICT_FALSE (n_trace > 0))
+               memif_trace_buffer (vm, node, mif, b1, next1, qid, &n_trace);
+             if (PREDICT_FALSE (n_trace > 0))
+               memif_trace_buffer (vm, node, mif, b2, next2, qid, &n_trace);
+             if (PREDICT_FALSE (n_trace > 0))
+               memif_trace_buffer (vm, node, mif, b3, next3, qid, &n_trace);
            }
 
-         /* enqueue buffer */
-         to_next[0] = first_bi0;
-         to_next += 1;
-         n_left_to_next--;
-
          /* enqueue */
-         vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
-                                          n_left_to_next, first_bi0, next0);
+         vlib_validate_buffer_enqueue_x4 (vm, node, next_index, to_next,
+                                          n_left_to_next, bi0, bi1, bi2, bi3,
+                                          next0, next1, next2, next3);
 
-         /* next packet */
-         n_rx_packets++;
-         n_rx_bytes += b0_total;
+         /* next */
+         n_from -= 4;
        }
-      while (num_slots && n_left_to_next)
+      while (n_from && n_left_to_next)
        {
-         vlib_buffer_t *first_b0 = 0;
-         u32 bi0 = 0, first_bi0 = 0;
-         b0_total = memif_copy_buffer_from_rx_ring (vm, mif, ring, mq,
-                                                    ring_size,
-                                                    n_buffer_bytes,
-                                                    &n_free_bufs, &first_b0,
-                                                    &first_bi0, &bi0,
-                                                    &num_slots);
-         if (PREDICT_FALSE (!first_bi0))
-           {
-             goto _invalid_pkt0;
-           }
+         /* enqueue buffer */
+         to_next[0] = bi0 = buffers[0];
+         to_next += 1;
+         n_left_to_next--;
+         buffers += 1;
+
+         b0 = vlib_get_buffer (vm, bi0);
+         vnet_buffer (b0)->sw_if_index[VLIB_RX] = mif->sw_if_index;
+         vnet_buffer (b0)->sw_if_index[VLIB_TX] = ~0;
 
          if (mode == MEMIF_INTERFACE_MODE_IP)
            {
-             next0 = memif_next_from_ip_hdr (node, first_b0);
+             next0 = memif_next_from_ip_hdr (node, b0);
            }
          else if (mode == MEMIF_INTERFACE_MODE_ETHERNET)
            {
              if (PREDICT_FALSE (mif->per_interface_next_index != ~0))
                next0 = mif->per_interface_next_index;
              else
-               /* redirect if feature path
-                * enabled */
-               vnet_feature_start_device_input_x1 (mif->sw_if_index,
-                                                   &next0, first_b0);
-           }
-
-         /* trace */
-         VLIB_BUFFER_TRACE_TRAJECTORY_INIT (first_b0);
-
-         if (PREDICT_FALSE (n_trace > 0))
-           {
-             if (PREDICT_TRUE (first_b0 != 0))
                {
-                 memif_input_trace_t *tr;
-                 vlib_trace_buffer (vm, node, next0, first_b0,
-                                    /* follow_chain */ 0);
-                 vlib_set_trace_count (vm, node, --n_trace);
-                 tr = vlib_add_trace (vm, node, first_b0, sizeof (*tr));
-                 tr->next_index = next0;
-                 tr->hw_if_index = mif->hw_if_index;
-                 tr->ring = qid;
+                 next0 = next_index;
+                 /* redirect if feature path enabled */
+                 vnet_feature_start_device_input_x1 (mif->sw_if_index,
+                                                     &next0, b0);
                }
            }
 
-         /* enqueue buffer */
-         to_next[0] = first_bi0;
-         to_next += 1;
-         n_left_to_next--;
+         /* trace */
+         if (PREDICT_FALSE (n_trace > 0))
+           memif_trace_buffer (vm, node, mif, b0, next0, qid, &n_trace);
 
          /* enqueue */
          vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
-                                          n_left_to_next, first_bi0, next0);
-
-         /* next packet */
-         n_rx_packets++;
-         n_rx_bytes += b0_total;
-         continue;
-       _invalid_pkt0:
-         ;
-       }
-      if (PREDICT_TRUE (n_rx_packets != 0))
-       {
-         vlib_put_next_frame (vm, node, next_index, n_left_to_next);
+                                          n_left_to_next, bi0, next0);
+
+         /* next */
+         n_from--;
        }
+      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
     }
-  CLIB_MEMORY_STORE_BARRIER ();
-  ring->tail = mq->last_head;
 
   vlib_increment_combined_counter (vnm->interface_main.combined_sw_if_counters
                                   + VNET_INTERFACE_COUNTER_RX, thread_index,
-                                  mif->hw_if_index, n_rx_packets,
+                                  mif->sw_if_index, n_rx_packets,
                                   n_rx_bytes);
 
+  /* refill ring with empty buffers */
+refill:
+  vec_reset_length (ptd->buffers);
+
+  head = ring->head;
+  n_slots = ring_size - head + mq->last_tail;
+  slot = head & mask;
+
+  n_slots &= ~7;
+
+  if (n_slots < 32)
+    goto done;
+
+  memif_desc_t desc_template, *dt = &desc_template;
+  clib_memset (dt, 0, sizeof (memif_desc_t));
+  dt->length = buffer_length;
+
+  n_alloc = vlib_buffer_alloc_to_ring_from_pool (
+    vm, mq->buffers, slot, ring_size, n_slots, mq->buffer_pool_index);
+  dt->region = mq->buffer_pool_index + 1;
+  offset = (u64) mif->regions[dt->region].shm - start_offset;
+
+  if (PREDICT_FALSE (n_alloc != n_slots))
+    vlib_error_count (vm, node->node_index,
+                     MEMIF_INPUT_ERROR_BUFFER_ALLOC_FAIL, 1);
+
+  head += n_alloc;
+
+  while (n_alloc)
+    {
+      memif_desc_t *d = ring->desc + slot;
+      u32 *bi = mq->buffers + slot;
+
+      if (PREDICT_FALSE (((slot + 7 > mask) || (n_alloc < 8))))
+       goto one_by_one;
+
+      clib_memcpy_fast (d + 0, dt, sizeof (memif_desc_t));
+      clib_memcpy_fast (d + 1, dt, sizeof (memif_desc_t));
+      clib_memcpy_fast (d + 2, dt, sizeof (memif_desc_t));
+      clib_memcpy_fast (d + 3, dt, sizeof (memif_desc_t));
+      clib_memcpy_fast (d + 4, dt, sizeof (memif_desc_t));
+      clib_memcpy_fast (d + 5, dt, sizeof (memif_desc_t));
+      clib_memcpy_fast (d + 6, dt, sizeof (memif_desc_t));
+      clib_memcpy_fast (d + 7, dt, sizeof (memif_desc_t));
+
+      d[0].offset = (u64) vlib_get_buffer (vm, bi[0])->data - offset;
+      d[1].offset = (u64) vlib_get_buffer (vm, bi[1])->data - offset;
+      d[2].offset = (u64) vlib_get_buffer (vm, bi[2])->data - offset;
+      d[3].offset = (u64) vlib_get_buffer (vm, bi[3])->data - offset;
+      d[4].offset = (u64) vlib_get_buffer (vm, bi[4])->data - offset;
+      d[5].offset = (u64) vlib_get_buffer (vm, bi[5])->data - offset;
+      d[6].offset = (u64) vlib_get_buffer (vm, bi[6])->data - offset;
+      d[7].offset = (u64) vlib_get_buffer (vm, bi[7])->data - offset;
+
+      slot = (slot + 8) & mask;
+      n_alloc -= 8;
+      continue;
+
+    one_by_one:
+      clib_memcpy_fast (d, dt, sizeof (memif_desc_t));
+      d[0].offset = (u64) vlib_get_buffer (vm, bi[0])->data - offset;
+
+      slot = (slot + 1) & mask;
+      n_alloc -= 1;
+    }
+
+  __atomic_store_n (&ring->head, head, __ATOMIC_RELEASE);
+
+done:
   return n_rx_packets;
 }
 
-uword
-CLIB_MULTIARCH_FN (memif_input_fn) (vlib_main_t * vm,
-                                   vlib_node_runtime_t * node,
-                                   vlib_frame_t * frame)
+
+VLIB_NODE_FN (memif_input_node) (vlib_main_t * vm,
+                                vlib_node_runtime_t * node,
+                                vlib_frame_t * frame)
 {
   u32 n_rx = 0;
-  memif_main_t *nm = &memif_main;
-  vnet_device_input_runtime_t *rt = (void *) node->runtime_data;
-  vnet_device_and_queue_t *dq;
-
-  foreach_device_and_queue (dq, rt->devices_and_queues)
-  {
-    memif_if_t *mif;
-    mif = vec_elt_at_index (nm->interfaces, dq->dev_instance);
-    if ((mif->flags & MEMIF_IF_FLAG_ADMIN_UP) &&
-       (mif->flags & MEMIF_IF_FLAG_CONNECTED))
-      {
-       if (mif->flags & MEMIF_IF_FLAG_IS_SLAVE)
-         {
-           if (mif->mode == MEMIF_INTERFACE_MODE_IP)
-             n_rx += memif_device_input_inline (vm, node, frame, mif,
-                                                MEMIF_RING_M2S, dq->queue_id,
-                                                MEMIF_INTERFACE_MODE_IP);
-           else
-             n_rx += memif_device_input_inline (vm, node, frame, mif,
-                                                MEMIF_RING_M2S, dq->queue_id,
-                                                MEMIF_INTERFACE_MODE_ETHERNET);
-         }
-       else
-         {
-           if (mif->mode == MEMIF_INTERFACE_MODE_IP)
-             n_rx += memif_device_input_inline (vm, node, frame, mif,
-                                                MEMIF_RING_S2M, dq->queue_id,
-                                                MEMIF_INTERFACE_MODE_IP);
-           else
-             n_rx += memif_device_input_inline (vm, node, frame, mif,
-                                                MEMIF_RING_S2M, dq->queue_id,
-                                                MEMIF_INTERFACE_MODE_ETHERNET);
-         }
-      }
-  }
+  memif_main_t *mm = &memif_main;
+  memif_interface_mode_t mode_ip = MEMIF_INTERFACE_MODE_IP;
+  memif_interface_mode_t mode_eth = MEMIF_INTERFACE_MODE_ETHERNET;
+
+  vnet_hw_if_rxq_poll_vector_t *pv;
+  pv = vnet_hw_if_get_rxq_poll_vector (vm, node);
+  for (int i = 0; i < vec_len (pv); i++)
+    {
+      memif_if_t *mif;
+      u32 qid;
+      mif = vec_elt_at_index (mm->interfaces, pv[i].dev_instance);
+      qid = pv[i].queue_id;
+      if ((mif->flags & MEMIF_IF_FLAG_ADMIN_UP) &&
+         (mif->flags & MEMIF_IF_FLAG_CONNECTED))
+       {
+         if (mif->flags & MEMIF_IF_FLAG_ZERO_COPY)
+           {
+             if (mif->mode == MEMIF_INTERFACE_MODE_IP)
+               n_rx +=
+                 memif_device_input_zc_inline (vm, node, mif, qid, mode_ip);
+             else
+               n_rx +=
+                 memif_device_input_zc_inline (vm, node, mif, qid, mode_eth);
+           }
+         else if (mif->flags & MEMIF_IF_FLAG_IS_SLAVE)
+           {
+             if (mif->mode == MEMIF_INTERFACE_MODE_IP)
+               n_rx += memif_device_input_inline (
+                 vm, node, mif, MEMIF_RING_M2S, qid, mode_ip);
+             else
+               n_rx += memif_device_input_inline (
+                 vm, node, mif, MEMIF_RING_M2S, qid, mode_eth);
+           }
+         else
+           {
+             if (mif->mode == MEMIF_INTERFACE_MODE_IP)
+               n_rx += memif_device_input_inline (
+                 vm, node, mif, MEMIF_RING_S2M, qid, mode_ip);
+             else
+               n_rx += memif_device_input_inline (
+                 vm, node, mif, MEMIF_RING_S2M, qid, mode_eth);
+           }
+       }
+    }
 
   return n_rx;
 }
 
-#ifndef CLIB_MULTIARCH_VARIANT
 /* *INDENT-OFF* */
 VLIB_REGISTER_NODE (memif_input_node) = {
-  .function = memif_input_fn,
   .name = "memif-input",
+  .flags = VLIB_NODE_FLAG_TRACE_SUPPORTED,
   .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,
+  .error_counters = memif_input_error_counters,
 };
 
-vlib_node_function_t __clib_weak memif_input_fn_avx512;
-vlib_node_function_t __clib_weak memif_input_fn_avx2;
-
-#if __x86_64__
-static void __clib_constructor
-memif_input_multiarch_select (void)
-{
-  if (memif_input_fn_avx512 && clib_cpu_supports_avx512f ())
-    memif_input_node.function = memif_input_fn_avx512;
-  else if (memif_input_fn_avx2 && clib_cpu_supports_avx2 ())
-    memif_input_node.function = memif_input_fn_avx2;
-}
-#endif
-#endif
-
 /* *INDENT-ON* */