vlib: refactor checksum offload support
[vpp.git] / src / vnet / devices / virtio / device.c
index add82b7..fb996d5 100644 (file)
@@ -161,8 +161,8 @@ virtio_memset_ring_u32 (u32 * ring, u32 start, u32 ring_size, u32 n_buffers)
 }
 
 static_always_inline void
-virtio_free_used_device_desc (vlib_main_t * vm, virtio_vring_t * vring,
-                             uword node_index)
+virtio_free_used_device_desc_split (vlib_main_t * vm, virtio_vring_t * vring,
+                                   uword node_index)
 {
   u16 used = vring->desc_in_use;
   u16 sz = vring->size;
@@ -227,8 +227,63 @@ virtio_free_used_device_desc (vlib_main_t * vm, virtio_vring_t * vring,
 }
 
 static_always_inline void
-set_checksum_offsets (vlib_buffer_t * b, virtio_net_hdr_v1_t * hdr, int is_l2)
+virtio_free_used_device_desc_packed (vlib_main_t * vm, virtio_vring_t * vring,
+                                    uword node_index)
 {
+  vring_packed_desc_t *d;
+  u16 sz = vring->size;
+  u16 last = vring->last_used_idx;
+  u16 n_buffers = 0, start;
+  u16 flags;
+
+  if (vring->desc_in_use == 0)
+    return;
+
+  d = &vring->packed_desc[last];
+  flags = d->flags;
+  start = d->id;
+
+  while ((flags & VRING_DESC_F_AVAIL) == (vring->used_wrap_counter << 7) &&
+        (flags & VRING_DESC_F_USED) == (vring->used_wrap_counter << 15))
+    {
+      last++;
+      n_buffers++;
+
+      if (last >= sz)
+       {
+         last = 0;
+         vring->used_wrap_counter ^= 1;
+       }
+      d = &vring->packed_desc[last];
+      flags = d->flags;
+    }
+
+  if (n_buffers)
+    {
+      vlib_buffer_free_from_ring (vm, vring->buffers, start, sz, n_buffers);
+      virtio_memset_ring_u32 (vring->buffers, start, sz, n_buffers);
+      vring->desc_in_use -= n_buffers;
+      vring->last_used_idx = last;
+    }
+}
+
+static_always_inline void
+virtio_free_used_device_desc (vlib_main_t * vm, virtio_vring_t * vring,
+                             uword node_index, int packed)
+{
+  if (packed)
+    virtio_free_used_device_desc_packed (vm, vring, node_index);
+  else
+    virtio_free_used_device_desc_split (vm, vring, node_index);
+
+}
+
+static_always_inline void
+set_checksum_offsets (vlib_buffer_t * b, virtio_net_hdr_v1_t * hdr,
+                     const int is_l2)
+{
+  u32 oflags = vnet_buffer2 (b)->oflags;
+
   if (b->flags & VNET_BUFFER_F_IS_IP4)
     {
       ip4_header_t *ip4;
@@ -237,11 +292,11 @@ set_checksum_offsets (vlib_buffer_t * b, virtio_net_hdr_v1_t * hdr, int is_l2)
                                         0 /* ip6 */ );
       hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
       hdr->csum_start = gho.l4_hdr_offset;     // 0x22;
-      if (b->flags & VNET_BUFFER_F_OFFLOAD_TCP_CKSUM)
+      if (oflags & VNET_BUFFER_OFFLOAD_F_TCP_CKSUM)
        {
          hdr->csum_offset = STRUCT_OFFSET_OF (tcp_header_t, checksum);
        }
-      else if (b->flags & VNET_BUFFER_F_OFFLOAD_UDP_CKSUM)
+      else if (oflags & VNET_BUFFER_OFFLOAD_F_UDP_CKSUM)
        {
          hdr->csum_offset = STRUCT_OFFSET_OF (udp_header_t, checksum);
        }
@@ -252,7 +307,7 @@ set_checksum_offsets (vlib_buffer_t * b, virtio_net_hdr_v1_t * hdr, int is_l2)
        */
       ip4 =
        (ip4_header_t *) (vlib_buffer_get_current (b) + gho.l3_hdr_offset);
-      if (b->flags & VNET_BUFFER_F_OFFLOAD_IP_CKSUM)
+      if (oflags & VNET_BUFFER_OFFLOAD_F_IP_CKSUM)
        ip4->checksum = ip4_header_checksum (ip4);
     }
   else if (b->flags & VNET_BUFFER_F_IS_IP6)
@@ -262,11 +317,11 @@ set_checksum_offsets (vlib_buffer_t * b, virtio_net_hdr_v1_t * hdr, int is_l2)
                                         1 /* ip6 */ );
       hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
       hdr->csum_start = gho.l4_hdr_offset;     // 0x36;
-      if (b->flags & VNET_BUFFER_F_OFFLOAD_TCP_CKSUM)
+      if (oflags & VNET_BUFFER_OFFLOAD_F_TCP_CKSUM)
        {
          hdr->csum_offset = STRUCT_OFFSET_OF (tcp_header_t, checksum);
        }
-      else if (b->flags & VNET_BUFFER_F_OFFLOAD_UDP_CKSUM)
+      else if (oflags & VNET_BUFFER_OFFLOAD_F_UDP_CKSUM)
        {
          hdr->csum_offset = STRUCT_OFFSET_OF (udp_header_t, checksum);
        }
@@ -274,8 +329,11 @@ set_checksum_offsets (vlib_buffer_t * b, virtio_net_hdr_v1_t * hdr, int is_l2)
 }
 
 static_always_inline void
-set_gso_offsets (vlib_buffer_t * b, virtio_net_hdr_v1_t * hdr, int is_l2)
+set_gso_offsets (vlib_buffer_t * b, virtio_net_hdr_v1_t * hdr,
+                const int is_l2)
 {
+  u32 oflags = vnet_buffer2 (b)->oflags;
+
   if (b->flags & VNET_BUFFER_F_IS_IP4)
     {
       ip4_header_t *ip4;
@@ -294,7 +352,7 @@ set_gso_offsets (vlib_buffer_t * b, virtio_net_hdr_v1_t * hdr, int is_l2)
        * virtio devices do not support IP4 checksum offload. So driver takes care
        * of it while doing tx.
        */
-      if (b->flags & VNET_BUFFER_F_OFFLOAD_IP_CKSUM)
+      if (oflags & VNET_BUFFER_OFFLOAD_F_IP_CKSUM)
        ip4->checksum = ip4_header_checksum (ip4);
     }
   else if (b->flags & VNET_BUFFER_F_IS_IP6)
@@ -338,8 +396,7 @@ add_buffer_to_slot (vlib_main_t * vm, vlib_node_runtime_t * node,
          goto done;
        }
     }
-  else if (b->flags & (VNET_BUFFER_F_OFFLOAD_TCP_CKSUM |
-                      VNET_BUFFER_F_OFFLOAD_UDP_CKSUM))
+  else if (b->flags & VNET_BUFFER_F_OFFLOAD)
     {
       if (csum_offload)
        set_checksum_offsets (b, hdr, is_l2);
@@ -504,6 +561,237 @@ done:
   return n_added;
 }
 
+static_always_inline u16
+add_buffer_to_slot_packed (vlib_main_t * vm, vlib_node_runtime_t * node,
+                          virtio_vring_t * vring, u32 bi, u16 next,
+                          int hdr_sz, int do_gso, int csum_offload,
+                          int is_pci, int is_tun, int is_indirect,
+                          int is_any_layout)
+{
+  u16 n_added = 0, flags = 0;
+  int is_l2 = !is_tun;
+  vring_packed_desc_t *d = &vring->packed_desc[next];
+  vlib_buffer_t *b = vlib_get_buffer (vm, bi);
+  virtio_net_hdr_v1_t *hdr = vlib_buffer_get_current (b) - hdr_sz;
+  u32 drop_inline = ~0;
+
+  clib_memset (hdr, 0, hdr_sz);
+
+  if (b->flags & VNET_BUFFER_F_GSO)
+    {
+      if (do_gso)
+       set_gso_offsets (b, hdr, is_l2);
+      else
+       {
+         drop_inline = VIRTIO_TX_ERROR_GSO_PACKET_DROP;
+         goto done;
+       }
+    }
+  else if (b->flags & VNET_BUFFER_F_OFFLOAD)
+    {
+      if (csum_offload)
+       set_checksum_offsets (b, hdr, is_l2);
+      else
+       {
+         drop_inline = VIRTIO_TX_ERROR_CSUM_OFFLOAD_PACKET_DROP;
+         goto done;
+       }
+    }
+  if (PREDICT_FALSE (b->flags & VLIB_BUFFER_IS_TRACED))
+    {
+      virtio_tx_trace (vm, node, b, bi, is_tun);
+    }
+
+  if (PREDICT_TRUE ((b->flags & VLIB_BUFFER_NEXT_PRESENT) == 0))
+    {
+      d->addr =
+       ((is_pci) ? vlib_buffer_get_current_pa (vm,
+                                               b) :
+        pointer_to_uword (vlib_buffer_get_current (b))) - hdr_sz;
+      d->len = b->current_length + hdr_sz;
+    }
+  else if (is_indirect)
+    {
+      /*
+       * We are using single vlib_buffer_t for indirect descriptor(s)
+       * chain. Single descriptor is 16 bytes and vlib_buffer_t
+       * has 2048 bytes space. So maximum long chain can have 128
+       * (=2048/16) indirect descriptors.
+       * It can easily support 65535 bytes of Jumbo frames with
+       * each data buffer size of 512 bytes minimum.
+       */
+      u32 indirect_buffer = 0;
+      if (PREDICT_FALSE (vlib_buffer_alloc (vm, &indirect_buffer, 1) == 0))
+       {
+         drop_inline = VIRTIO_TX_ERROR_INDIRECT_DESC_ALLOC_FAILED;
+         goto done;
+       }
+
+      vlib_buffer_t *indirect_desc = vlib_get_buffer (vm, indirect_buffer);
+      indirect_desc->current_data = 0;
+      indirect_desc->flags |= VLIB_BUFFER_NEXT_PRESENT;
+      indirect_desc->next_buffer = bi;
+      bi = indirect_buffer;
+
+      vring_packed_desc_t *id =
+       (vring_packed_desc_t *) vlib_buffer_get_current (indirect_desc);
+      u32 count = 1;
+      if (is_pci)
+       {
+         d->addr = vlib_physmem_get_pa (vm, id);
+         id->addr = vlib_buffer_get_current_pa (vm, b) - hdr_sz;
+
+         /*
+          * If VIRTIO_F_ANY_LAYOUT is not negotiated, then virtio_net_hdr
+          * should be presented in separate descriptor and data will start
+          * from next descriptor.
+          */
+         if (is_any_layout)
+           id->len = b->current_length + hdr_sz;
+         else
+           {
+             id->len = hdr_sz;
+             id->flags = 0;
+             id->id = 0;
+             count++;
+             id++;
+             id->addr = vlib_buffer_get_current_pa (vm, b);
+             id->len = b->current_length;
+           }
+         while (b->flags & VLIB_BUFFER_NEXT_PRESENT)
+           {
+             id->flags = 0;
+             id->id = 0;
+             count++;
+             id++;
+             b = vlib_get_buffer (vm, b->next_buffer);
+             id->addr = vlib_buffer_get_current_pa (vm, b);
+             id->len = b->current_length;
+           }
+       }
+      id->flags = 0;
+      id->id = 0;
+      d->len = count * sizeof (vring_packed_desc_t);
+      flags = VRING_DESC_F_INDIRECT;
+    }
+  else
+    {
+      ASSERT (0);
+    }
+  if (vring->avail_wrap_counter)
+    {
+      flags |= VRING_DESC_F_AVAIL;
+      flags &= ~VRING_DESC_F_USED;
+    }
+  else
+    {
+      flags &= ~VRING_DESC_F_AVAIL;
+      flags |= VRING_DESC_F_USED;
+    }
+
+  d->id = next;
+  d->flags = flags;
+  vring->buffers[next] = bi;
+  n_added++;
+
+done:
+  if (drop_inline != ~0)
+    virtio_interface_drop_inline (vm, node->node_index, &bi, 1, drop_inline);
+
+  return n_added;
+}
+
+static_always_inline uword
+virtio_interface_tx_packed_gso_inline (vlib_main_t * vm,
+                                      vlib_node_runtime_t * node,
+                                      virtio_if_t * vif,
+                                      virtio_if_type_t type,
+                                      virtio_vring_t * vring,
+                                      u32 * buffers, u16 n_left,
+                                      const int do_gso,
+                                      const int csum_offload)
+{
+  int is_pci = (type == VIRTIO_IF_TYPE_PCI);
+  int is_tun = (type == VIRTIO_IF_TYPE_TUN);
+  int is_indirect =
+    ((vif->features & VIRTIO_FEATURE (VIRTIO_RING_F_INDIRECT_DESC)) != 0);
+  int is_any_layout =
+    ((vif->features & VIRTIO_FEATURE (VIRTIO_F_ANY_LAYOUT)) != 0);
+  const int hdr_sz = vif->virtio_net_hdr_sz;
+  u16 sz = vring->size;
+  u16 used, next, n_buffers = 0, n_buffers_left = 0;
+  u16 n_vectors = n_left;
+
+
+  used = vring->desc_in_use;
+  next = vring->desc_next;
+
+  if (vif->packet_buffering)
+    {
+      n_buffers = n_buffers_left = virtio_vring_n_buffers (vring->buffering);
+
+      while (n_buffers_left && used < sz)
+       {
+         u16 n_added = 0;
+
+         u32 bi = virtio_vring_buffering_read_from_front (vring->buffering);
+         if (bi == ~0)
+           break;
+         n_added = add_buffer_to_slot_packed (vm, node,
+                                              vring, bi, next,
+                                              hdr_sz, do_gso, csum_offload,
+                                              is_pci, is_tun, is_indirect,
+                                              is_any_layout);
+         n_buffers_left--;
+         if (PREDICT_FALSE (n_added == 0))
+           continue;
+
+         used++;
+         next++;
+         if (next >= sz)
+           {
+             next = 0;
+             vring->avail_wrap_counter ^= 1;
+           }
+       }
+    }
+
+  while (n_left && used < sz)
+    {
+      u16 n_added = 0;
+
+      n_added = add_buffer_to_slot_packed (vm, node,
+                                          vring, buffers[0], next,
+                                          hdr_sz, do_gso, csum_offload,
+                                          is_pci, is_tun, is_indirect,
+                                          is_any_layout);
+      buffers++;
+      n_left--;
+      if (PREDICT_FALSE (n_added == 0))
+       continue;
+
+      used++;
+      next++;
+      if (next >= sz)
+       {
+         next = 0;
+         vring->avail_wrap_counter ^= 1;
+       }
+    }
+
+  if (n_left != n_vectors || n_buffers != n_buffers_left)
+    {
+      CLIB_MEMORY_STORE_BARRIER ();
+      vring->desc_next = next;
+      vring->desc_in_use = used;
+      CLIB_MEMORY_BARRIER ();
+      if (vring->device_event->flags != VRING_EVENT_F_DISABLE)
+       virtio_kick (vm, vring, vif);
+    }
+
+  return n_left;
+}
+
 static_always_inline void
 virtio_find_free_desc (virtio_vring_t * vring, u16 size, u16 mask,
                       u16 req, u16 next, u32 * first_free_desc_index,
@@ -541,11 +829,13 @@ virtio_find_free_desc (virtio_vring_t * vring, u16 size, u16 mask,
 }
 
 static_always_inline u16
-virtio_interface_tx_gso_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
-                               virtio_if_t * vif,
-                               virtio_if_type_t type, virtio_vring_t * vring,
-                               u32 * buffers, u16 n_left, int do_gso,
-                               int csum_offload)
+virtio_interface_tx_split_gso_inline (vlib_main_t * vm,
+                                     vlib_node_runtime_t * node,
+                                     virtio_if_t * vif,
+                                     virtio_if_type_t type,
+                                     virtio_vring_t * vring, u32 * buffers,
+                                     u16 n_left, int do_gso,
+                                     int csum_offload)
 {
   u16 used, next, avail, n_buffers = 0, n_buffers_left = 0;
   int is_pci = (type == VIRTIO_IF_TYPE_PCI);
@@ -638,38 +928,56 @@ virtio_interface_tx_gso_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
 
   if (n_left != n_vectors || n_buffers != n_buffers_left)
     {
-      CLIB_MEMORY_STORE_BARRIER ();
-      vring->avail->idx = avail;
+      clib_atomic_store_seq_cst (&vring->avail->idx, avail);
       vring->desc_next = next;
       vring->desc_in_use = used;
-      if ((vring->used->flags & VRING_USED_F_NO_NOTIFY) == 0)
+      if ((clib_atomic_load_seq_cst (&vring->used->flags) &
+          VRING_USED_F_NO_NOTIFY) == 0)
        virtio_kick (vm, vring, vif);
     }
 
   return n_left;
 }
 
+static_always_inline u16
+virtio_interface_tx_gso_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
+                               virtio_if_t * vif,
+                               virtio_if_type_t type, virtio_vring_t * vring,
+                               u32 * buffers, u16 n_left, int packed,
+                               int do_gso, int csum_offload)
+{
+  if (packed)
+    return virtio_interface_tx_packed_gso_inline (vm, node, vif, type, vring,
+                                                 buffers, n_left,
+                                                 do_gso, csum_offload);
+  else
+    return virtio_interface_tx_split_gso_inline (vm, node, vif, type, vring,
+                                                buffers, n_left,
+                                                do_gso, csum_offload);
+}
+
 static_always_inline u16
 virtio_interface_tx_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
                            virtio_if_t * vif,
                            virtio_vring_t * vring, virtio_if_type_t type,
-                           u32 * buffers, u16 n_left)
+                           u32 * buffers, u16 n_left, int packed)
 {
   vnet_main_t *vnm = vnet_get_main ();
   vnet_hw_interface_t *hw = vnet_get_hw_interface (vnm, vif->hw_if_index);
 
   if (hw->flags & VNET_HW_INTERFACE_FLAG_SUPPORTS_GSO)
     return virtio_interface_tx_gso_inline (vm, node, vif, type, vring,
-                                          buffers, n_left, 1 /* do_gso */ ,
+                                          buffers, n_left, packed,
+                                          1 /* do_gso */ ,
                                           1 /* checksum offload */ );
   else if (hw->flags & VNET_HW_INTERFACE_FLAG_SUPPORTS_TX_L4_CKSUM_OFFLOAD)
     return virtio_interface_tx_gso_inline (vm, node, vif, type, vring,
-                                          buffers, n_left,
+                                          buffers, n_left, packed,
                                           0 /* no do_gso */ ,
                                           1 /* checksum offload */ );
   else
     return virtio_interface_tx_gso_inline (vm, node, vif, type, vring,
-                                          buffers, n_left,
+                                          buffers, n_left, packed,
                                           0 /* no do_gso */ ,
                                           0 /* no checksum offload */ );
 }
@@ -686,16 +994,15 @@ VNET_DEVICE_CLASS_TX_FN (virtio_device_class) (vlib_main_t * vm,
   u16 n_left = frame->n_vectors;
   u32 *buffers = vlib_frame_vector_args (frame);
   u32 to[GRO_TO_VECTOR_SIZE (n_left)];
+  int packed = vif->is_packed;
+  u16 n_vectors = frame->n_vectors;
 
   clib_spinlock_lock_if_init (&vring->lockp);
 
-  if ((vring->used->flags & VRING_USED_F_NO_NOTIFY) == 0 &&
-      (vring->last_kick_avail_idx != vring->avail->idx))
-    virtio_kick (vm, vring, vif);
-
   if (vif->packet_coalesce)
     {
-      n_left = vnet_gro_inline (vm, vring->flow_table, buffers, n_left, to);
+      n_vectors = n_left =
+       vnet_gro_inline (vm, vring->flow_table, buffers, n_left, to);
       buffers = to;
     }
 
@@ -703,23 +1010,23 @@ VNET_DEVICE_CLASS_TX_FN (virtio_device_class) (vlib_main_t * vm,
 
 retry:
   /* free consumed buffers */
-  virtio_free_used_device_desc (vm, vring, node->node_index);
+  virtio_free_used_device_desc (vm, vring, node->node_index, packed);
 
   if (vif->type == VIRTIO_IF_TYPE_TAP)
     n_left = virtio_interface_tx_inline (vm, node, vif, vring,
                                         VIRTIO_IF_TYPE_TAP,
-                                        &buffers[frame->n_vectors - n_left],
-                                        n_left);
+                                        &buffers[n_vectors - n_left],
+                                        n_left, packed);
   else if (vif->type == VIRTIO_IF_TYPE_PCI)
     n_left = virtio_interface_tx_inline (vm, node, vif, vring,
                                         VIRTIO_IF_TYPE_PCI,
-                                        &buffers[frame->n_vectors - n_left],
-                                        n_left);
+                                        &buffers[n_vectors - n_left],
+                                        n_left, packed);
   else if (vif->type == VIRTIO_IF_TYPE_TUN)
     n_left = virtio_interface_tx_inline (vm, node, vif, vring,
                                         VIRTIO_IF_TYPE_TUN,
-                                        &buffers[frame->n_vectors - n_left],
-                                        n_left);
+                                        &buffers[n_vectors - n_left],
+                                        n_left, packed);
   else
     ASSERT (0);
 
@@ -730,15 +1037,14 @@ retry:
     {
       u16 n_buffered = virtio_vring_buffering_store_packets (vring->buffering,
                                                             &buffers
-                                                            [frame->n_vectors
+                                                            [n_vectors
                                                              - n_left],
                                                             n_left);
-      buffers += n_buffered;
       n_left -= n_buffered;
     }
   if (n_left)
     virtio_interface_drop_inline (vm, node->node_index,
-                                 &buffers[frame->n_vectors - n_left], n_left,
+                                 &buffers[n_vectors - n_left], n_left,
                                  VIRTIO_TX_ERROR_NO_FREE_SLOTS);
 
   clib_spinlock_unlock_if_init (&vring->lockp);
@@ -772,6 +1078,24 @@ virtio_clear_hw_interface_counters (u32 instance)
   /* Nothing for now */
 }
 
+static_always_inline void
+virtio_set_rx_interrupt (virtio_if_t * vif, virtio_vring_t * vring)
+{
+  if (vif->is_packed)
+    vring->driver_event->flags &= ~VRING_EVENT_F_DISABLE;
+  else
+    vring->avail->flags &= ~VRING_AVAIL_F_NO_INTERRUPT;
+}
+
+static_always_inline void
+virtio_set_rx_polling (virtio_if_t * vif, virtio_vring_t * vring)
+{
+  if (vif->is_packed)
+    vring->driver_event->flags |= VRING_EVENT_F_DISABLE;
+  else
+    vring->avail->flags |= VRING_AVAIL_F_NO_INTERRUPT;
+}
+
 static clib_error_t *
 virtio_interface_rx_mode_change (vnet_main_t * vnm, u32 hw_if_index, u32 qid,
                                 vnet_hw_if_rx_mode mode)
@@ -784,7 +1108,7 @@ virtio_interface_rx_mode_change (vnet_main_t * vnm, u32 hw_if_index, u32 qid,
 
   if (vif->type == VIRTIO_IF_TYPE_PCI && !(vif->support_int_mode))
     {
-      rx_vring->avail->flags |= VRING_AVAIL_F_NO_INTERRUPT;
+      virtio_set_rx_polling (vif, rx_vring);
       return clib_error_return (0, "interrupt mode is not supported");
     }
 
@@ -799,7 +1123,7 @@ virtio_interface_rx_mode_change (vnet_main_t * vnm, u32 hw_if_index, u32 qid,
                                       virtio_send_interrupt_node.index,
                                       VIRTIO_EVENT_STOP_TIMER, 0);
        }
-      rx_vring->avail->flags |= VRING_AVAIL_F_NO_INTERRUPT;
+      virtio_set_rx_polling (vif, rx_vring);
     }
   else
     {
@@ -811,7 +1135,7 @@ virtio_interface_rx_mode_change (vnet_main_t * vnm, u32 hw_if_index, u32 qid,
                                       virtio_send_interrupt_node.index,
                                       VIRTIO_EVENT_START_TIMER, 0);
        }
-      rx_vring->avail->flags &= ~VRING_AVAIL_F_NO_INTERRUPT;
+      virtio_set_rx_interrupt (vif, rx_vring);
     }
 
   rx_vring->mode = mode;