2 *------------------------------------------------------------------
3 * Copyright (c) 2016 Cisco and/or its affiliates.
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at:
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 *------------------------------------------------------------------
18 #include <sys/types.h>
22 #include <vlib/vlib.h>
23 #include <vlib/unix/unix.h>
24 #include <vnet/vnet.h>
25 #include <vnet/ethernet/ethernet.h>
26 #include <vnet/gso/gro_func.h>
27 #include <vnet/gso/hdr_offset_parser.h>
28 #include <vnet/ip/ip4_packet.h>
29 #include <vnet/ip/ip6_packet.h>
30 #include <vnet/tcp/tcp_packet.h>
31 #include <vnet/udp/udp_packet.h>
32 #include <vnet/devices/virtio/virtio.h>
34 #define foreach_virtio_tx_func_error \
35 _(NO_FREE_SLOTS, "no free tx slots") \
36 _(TRUNC_PACKET, "packet > buffer size -- truncated in tx ring") \
37 _(PENDING_MSGS, "pending msgs in tx ring") \
38 _(INDIRECT_DESC_ALLOC_FAILED, "indirect descriptor allocation failed - packet drop") \
39 _(OUT_OF_ORDER, "out-of-order buffers in used ring") \
40 _(GSO_PACKET_DROP, "gso disabled on itf -- gso packet drop") \
41 _(CSUM_OFFLOAD_PACKET_DROP, "checksum offload disabled on itf -- csum offload packet drop")
45 #define _(f,s) VIRTIO_TX_ERROR_##f,
46 foreach_virtio_tx_func_error
49 } virtio_tx_func_error_t;
51 static char *virtio_tx_func_error_strings[] = {
53 foreach_virtio_tx_func_error
58 format_virtio_device (u8 * s, va_list * args)
60 u32 dev_instance = va_arg (*args, u32);
61 int verbose = va_arg (*args, int);
62 u32 indent = format_get_indent (s);
64 s = format (s, "VIRTIO interface");
67 s = format (s, "\n%U instance %u", format_white_space, indent + 2,
78 generic_header_offset_t gho;
82 format_virtio_tx_trace (u8 * s, va_list * va)
84 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*va, vlib_main_t *);
85 CLIB_UNUSED (vlib_node_t * node) = va_arg (*va, vlib_node_t *);
86 virtio_tx_trace_t *t = va_arg (*va, virtio_tx_trace_t *);
87 u32 indent = format_get_indent (s);
89 s = format (s, "%Ubuffer 0x%x: %U\n",
90 format_white_space, indent,
91 t->buffer_index, format_vnet_buffer, &t->buffer);
93 format (s, "%U%U\n", format_white_space, indent,
94 format_generic_header_offset, &t->gho);
96 format (s, "%U%U", format_white_space, indent,
97 format_ethernet_header_with_length, t->buffer.pre_data,
98 sizeof (t->buffer.pre_data));
102 static_always_inline void
103 virtio_interface_drop_inline (vlib_main_t * vm, uword node_index,
104 u32 * buffers, u16 n,
105 virtio_tx_func_error_t error)
107 vlib_error_count (vm, node_index, error, n);
108 vlib_buffer_free (vm, buffers, n);
111 static_always_inline void
112 virtio_memset_ring_u32 (u32 * ring, u32 start, u32 ring_size, u32 n_buffers)
114 ASSERT (n_buffers <= ring_size);
116 if (PREDICT_TRUE (start + n_buffers <= ring_size))
118 clib_memset_u32 (ring + start, ~0, n_buffers);
122 clib_memset_u32 (ring + start, ~0, ring_size - start);
123 clib_memset_u32 (ring, ~0, n_buffers - (ring_size - start));
127 static_always_inline void
128 virtio_free_used_device_desc (vlib_main_t * vm, virtio_vring_t * vring,
131 u16 used = vring->desc_in_use;
132 u16 sz = vring->size;
134 u16 last = vring->last_used_idx;
135 u16 n_left = vring->used->idx - last;
136 u16 out_of_order_count = 0;
143 vring_used_elem_t *e = &vring->used->ring[last & mask];
145 slot = n_buffers = e->id;
147 while (e->id == (n_buffers & mask))
152 vring_desc_t *d = &vring->desc[e->id];
154 while (d->flags & VRING_DESC_F_NEXT)
158 d = &vring->desc[next];
162 e = &vring->used->ring[last & mask];
164 vlib_buffer_free_from_ring (vm, vring->buffers, slot,
165 sz, (n_buffers - slot));
166 virtio_memset_ring_u32 (vring->buffers, slot, sz, (n_buffers - slot));
167 used -= (n_buffers - slot);
171 vlib_buffer_free (vm, &vring->buffers[e->id], 1);
172 vring->buffers[e->id] = ~0;
176 out_of_order_count++;
177 vring->flags |= VRING_TX_OUT_OF_ORDER;
182 * Some vhost-backends give buffers back in out-of-order fashion in used ring.
183 * It impacts the overall virtio-performance.
185 if (out_of_order_count)
186 vlib_error_count (vm, node_index, VIRTIO_TX_ERROR_OUT_OF_ORDER,
189 vring->desc_in_use = used;
190 vring->last_used_idx = last;
193 static_always_inline void
194 set_checksum_offsets (vlib_buffer_t * b, virtio_net_hdr_v1_t * hdr, int is_l2)
196 if (b->flags & VNET_BUFFER_F_IS_IP4)
199 generic_header_offset_t gho = { 0 };
200 vnet_generic_header_offset_parser (b, &gho, is_l2, 1 /* ip4 */ ,
202 hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
203 hdr->csum_start = gho.l4_hdr_offset; // 0x22;
204 if (b->flags & VNET_BUFFER_F_OFFLOAD_TCP_CKSUM)
206 hdr->csum_offset = STRUCT_OFFSET_OF (tcp_header_t, checksum);
208 else if (b->flags & VNET_BUFFER_F_OFFLOAD_UDP_CKSUM)
210 hdr->csum_offset = STRUCT_OFFSET_OF (udp_header_t, checksum);
214 * virtio devices do not support IP4 checksum offload. So driver takes care
215 * of it while doing tx.
218 (ip4_header_t *) (vlib_buffer_get_current (b) + gho.l3_hdr_offset);
219 if (b->flags & VNET_BUFFER_F_OFFLOAD_IP_CKSUM)
220 ip4->checksum = ip4_header_checksum (ip4);
222 else if (b->flags & VNET_BUFFER_F_IS_IP6)
224 generic_header_offset_t gho = { 0 };
225 vnet_generic_header_offset_parser (b, &gho, is_l2, 0 /* ip4 */ ,
227 hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
228 hdr->csum_start = gho.l4_hdr_offset; // 0x36;
229 if (b->flags & VNET_BUFFER_F_OFFLOAD_TCP_CKSUM)
231 hdr->csum_offset = STRUCT_OFFSET_OF (tcp_header_t, checksum);
233 else if (b->flags & VNET_BUFFER_F_OFFLOAD_UDP_CKSUM)
235 hdr->csum_offset = STRUCT_OFFSET_OF (udp_header_t, checksum);
240 static_always_inline void
241 set_gso_offsets (vlib_buffer_t * b, virtio_net_hdr_v1_t * hdr, int is_l2)
243 if (b->flags & VNET_BUFFER_F_IS_IP4)
246 generic_header_offset_t gho = { 0 };
247 vnet_generic_header_offset_parser (b, &gho, is_l2, 1 /* ip4 */ ,
249 hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
250 hdr->gso_size = vnet_buffer2 (b)->gso_size;
251 hdr->hdr_len = gho.hdr_sz;
252 hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
253 hdr->csum_start = gho.l4_hdr_offset; // 0x22;
254 hdr->csum_offset = STRUCT_OFFSET_OF (tcp_header_t, checksum);
256 (ip4_header_t *) (vlib_buffer_get_current (b) + gho.l3_hdr_offset);
258 * virtio devices do not support IP4 checksum offload. So driver takes care
259 * of it while doing tx.
261 if (b->flags & VNET_BUFFER_F_OFFLOAD_IP_CKSUM)
262 ip4->checksum = ip4_header_checksum (ip4);
264 else if (b->flags & VNET_BUFFER_F_IS_IP6)
266 generic_header_offset_t gho = { 0 };
267 vnet_generic_header_offset_parser (b, &gho, is_l2, 0 /* ip4 */ ,
269 hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
270 hdr->gso_size = vnet_buffer2 (b)->gso_size;
271 hdr->hdr_len = gho.hdr_sz;
272 hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
273 hdr->csum_start = gho.l4_hdr_offset; // 0x36;
274 hdr->csum_offset = STRUCT_OFFSET_OF (tcp_header_t, checksum);
278 static_always_inline u16
279 add_buffer_to_slot (vlib_main_t * vm, virtio_if_t * vif,
280 virtio_if_type_t type, virtio_vring_t * vring,
281 u32 bi, u16 free_desc_count,
282 u16 avail, u16 next, u16 mask, int do_gso,
283 int csum_offload, uword node_index)
286 int hdr_sz = vif->virtio_net_hdr_sz;
288 d = &vring->desc[next];
289 vlib_buffer_t *b = vlib_get_buffer (vm, bi);
290 virtio_net_hdr_v1_t *hdr = vlib_buffer_get_current (b) - hdr_sz;
291 int is_l2 = (type & (VIRTIO_IF_TYPE_TAP | VIRTIO_IF_TYPE_PCI));
293 clib_memset (hdr, 0, hdr_sz);
295 if (b->flags & VNET_BUFFER_F_GSO)
298 set_gso_offsets (b, hdr, is_l2);
301 virtio_interface_drop_inline (vm, node_index, &bi, 1,
302 VIRTIO_TX_ERROR_GSO_PACKET_DROP);
306 else if (b->flags & (VNET_BUFFER_F_OFFLOAD_TCP_CKSUM |
307 VNET_BUFFER_F_OFFLOAD_UDP_CKSUM))
310 set_checksum_offsets (b, hdr, is_l2);
313 virtio_interface_drop_inline (vm, node_index, &bi, 1,
314 VIRTIO_TX_ERROR_CSUM_OFFLOAD_PACKET_DROP);
319 if (PREDICT_TRUE ((b->flags & VLIB_BUFFER_NEXT_PRESENT) == 0))
322 ((type == VIRTIO_IF_TYPE_PCI) ? vlib_buffer_get_current_pa (vm,
324 pointer_to_uword (vlib_buffer_get_current (b))) - hdr_sz;
325 d->len = b->current_length + hdr_sz;
328 else if (vif->features & VIRTIO_FEATURE (VIRTIO_RING_F_INDIRECT_DESC))
331 * We are using single vlib_buffer_t for indirect descriptor(s)
332 * chain. Single descriptor is 16 bytes and vlib_buffer_t
333 * has 2048 bytes space. So maximum long chain can have 128
334 * (=2048/16) indirect descriptors.
335 * It can easily support 65535 bytes of Jumbo frames with
336 * each data buffer size of 512 bytes minimum.
338 u32 indirect_buffer = 0;
339 if (PREDICT_FALSE (vlib_buffer_alloc (vm, &indirect_buffer, 1) == 0))
341 virtio_interface_drop_inline (vm, node_index, &bi, 1,
342 VIRTIO_TX_ERROR_INDIRECT_DESC_ALLOC_FAILED);
346 vlib_buffer_t *indirect_desc = vlib_get_buffer (vm, indirect_buffer);
347 indirect_desc->current_data = 0;
348 indirect_desc->flags |= VLIB_BUFFER_NEXT_PRESENT;
349 indirect_desc->next_buffer = bi;
350 bi = indirect_buffer;
353 (vring_desc_t *) vlib_buffer_get_current (indirect_desc);
355 if (type == VIRTIO_IF_TYPE_PCI)
357 d->addr = vlib_physmem_get_pa (vm, id);
358 id->addr = vlib_buffer_get_current_pa (vm, b) - hdr_sz;
361 * If VIRTIO_F_ANY_LAYOUT is not negotiated, then virtio_net_hdr
362 * should be presented in separate descriptor and data will start
363 * from next descriptor.
366 (vif->features & VIRTIO_FEATURE (VIRTIO_F_ANY_LAYOUT)))
367 id->len = b->current_length + hdr_sz;
371 id->flags = VRING_DESC_F_NEXT;
375 id->addr = vlib_buffer_get_current_pa (vm, b);
376 id->len = b->current_length;
378 while (b->flags & VLIB_BUFFER_NEXT_PRESENT)
380 id->flags = VRING_DESC_F_NEXT;
384 b = vlib_get_buffer (vm, b->next_buffer);
385 id->addr = vlib_buffer_get_current_pa (vm, b);
386 id->len = b->current_length;
389 else /* VIRTIO_IF_TYPE_[TAP | TUN] */
391 d->addr = pointer_to_uword (id);
392 /* first buffer in chain */
393 id->addr = pointer_to_uword (vlib_buffer_get_current (b)) - hdr_sz;
394 id->len = b->current_length + hdr_sz;
396 while (b->flags & VLIB_BUFFER_NEXT_PRESENT)
398 id->flags = VRING_DESC_F_NEXT;
402 b = vlib_get_buffer (vm, b->next_buffer);
403 id->addr = pointer_to_uword (vlib_buffer_get_current (b));
404 id->len = b->current_length;
409 d->len = count * sizeof (vring_desc_t);
410 d->flags = VRING_DESC_F_INDIRECT;
412 else if (type == VIRTIO_IF_TYPE_PCI)
415 vlib_buffer_t *b_temp = b;
416 u16 n_buffers_in_chain = 1;
419 * Check the length of the chain for the required number of
420 * descriptors. Return from here, retry to get more descriptors,
421 * if chain length is greater than available descriptors.
423 while (b_temp->flags & VLIB_BUFFER_NEXT_PRESENT)
425 n_buffers_in_chain++;
426 b_temp = vlib_get_buffer (vm, b_temp->next_buffer);
429 if (n_buffers_in_chain > free_desc_count)
430 return n_buffers_in_chain;
432 d->addr = vlib_buffer_get_current_pa (vm, b) - hdr_sz;
433 d->len = b->current_length + hdr_sz;
435 while (b->flags & VLIB_BUFFER_NEXT_PRESENT)
437 d->flags = VRING_DESC_F_NEXT;
438 vring->buffers[count] = bi;
440 ~(VLIB_BUFFER_NEXT_PRESENT | VLIB_BUFFER_TOTAL_LENGTH_VALID);
444 count = (count + 1) & mask;
446 d = &vring->desc[count];
447 b = vlib_get_buffer (vm, bi);
448 d->addr = vlib_buffer_get_current_pa (vm, b);
449 d->len = b->current_length;
452 vring->buffers[count] = bi;
453 vring->avail->ring[avail & mask] = next;
461 vring->buffers[next] = bi;
462 vring->avail->ring[avail & mask] = next;
467 static_always_inline void
468 virtio_find_free_desc (virtio_vring_t * vring, u16 size, u16 mask,
469 u16 req, u16 next, u32 * first_free_desc_index,
470 u16 * free_desc_count)
473 /* next is used as hint: from where to start looking */
474 for (u16 i = 0; i < size; i++, next++)
476 if (vring->buffers[next & mask] == ~0)
478 if (*first_free_desc_index == ~0)
480 *first_free_desc_index = (next & mask);
482 (*free_desc_count)++;
489 if (start + *free_desc_count == i)
491 (*free_desc_count)++;
503 static_always_inline uword
504 virtio_interface_tx_gso_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
505 vlib_frame_t * frame, virtio_if_t * vif,
506 virtio_if_type_t type, int do_gso,
507 int csum_offload, int do_gro)
509 u16 n_left = frame->n_vectors;
510 virtio_vring_t *vring;
511 u16 qid = vm->thread_index % vif->num_txqs;
512 vring = vec_elt_at_index (vif->txq_vrings, qid);
513 u16 used, next, avail;
514 u16 sz = vring->size;
517 u32 *buffers = vlib_frame_vector_args (frame);
518 u32 to[GRO_TO_VECTOR_SIZE (n_left)];
520 clib_spinlock_lock_if_init (&vring->lockp);
522 if ((vring->used->flags & VRING_USED_F_NO_NOTIFY) == 0 &&
523 (vring->last_kick_avail_idx != vring->avail->idx))
524 virtio_kick (vm, vring, vif);
528 n_left = vnet_gro_inline (vm, vring->flow_table, buffers, n_left, to);
533 /* free consumed buffers */
534 virtio_free_used_device_desc (vm, vring, node->node_index);
536 used = vring->desc_in_use;
537 next = vring->desc_next;
538 avail = vring->avail->idx;
540 u16 free_desc_count = 0;
542 if (PREDICT_FALSE (vring->flags & VRING_TX_OUT_OF_ORDER))
544 u32 first_free_desc_index = ~0;
546 virtio_find_free_desc (vring, sz, mask, n_left, next,
547 &first_free_desc_index, &free_desc_count);
550 next = first_free_desc_index;
553 free_desc_count = sz - used;
555 while (n_left && free_desc_count)
558 virtio_tx_trace_t *t;
560 vlib_buffer_t *b0 = vlib_get_buffer (vm, buffers[0]);
561 if (b0->flags & VLIB_BUFFER_IS_TRACED)
563 t = vlib_add_trace (vm, node, b0, sizeof (t[0]));
564 t->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_TX];
565 t->buffer_index = buffers[0];
566 if (type == VIRTIO_IF_TYPE_TUN)
568 int is_ip4 = 0, is_ip6 = 0;
570 switch (((u8 *) vlib_buffer_get_current (b0))[0] & 0xf0)
581 vnet_generic_header_offset_parser (b0, &t->gho, 0, is_ip4,
585 vnet_generic_header_offset_parser (b0, &t->gho, 1,
587 VNET_BUFFER_F_IS_IP4,
589 VNET_BUFFER_F_IS_IP6);
591 clib_memcpy_fast (&t->buffer, b0,
592 sizeof (*b0) - sizeof (b0->pre_data));
593 clib_memcpy_fast (t->buffer.pre_data, vlib_buffer_get_current (b0),
594 sizeof (t->buffer.pre_data));
597 add_buffer_to_slot (vm, vif, type, vring, buffers[0], free_desc_count,
598 avail, next, mask, do_gso, csum_offload,
601 if (PREDICT_FALSE (n_added == 0))
607 else if (PREDICT_FALSE (n_added > free_desc_count))
611 next = (next + n_added) & mask;
615 free_desc_count -= n_added;
618 if (n_left != frame->n_vectors)
620 CLIB_MEMORY_STORE_BARRIER ();
621 vring->avail->idx = avail;
622 vring->desc_next = next;
623 vring->desc_in_use = used;
624 if ((vring->used->flags & VRING_USED_F_NO_NOTIFY) == 0)
625 virtio_kick (vm, vring, vif);
633 virtio_interface_drop_inline (vm, node->node_index,
635 VIRTIO_TX_ERROR_NO_FREE_SLOTS);
638 clib_spinlock_unlock_if_init (&vring->lockp);
640 return frame->n_vectors - n_left;
643 static_always_inline uword
644 virtio_interface_tx_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
645 vlib_frame_t * frame, virtio_if_t * vif,
646 virtio_if_type_t type)
648 vnet_main_t *vnm = vnet_get_main ();
649 vnet_hw_interface_t *hw = vnet_get_hw_interface (vnm, vif->hw_if_index);
651 if (hw->flags & VNET_HW_INTERFACE_FLAG_SUPPORTS_GSO)
652 return virtio_interface_tx_gso_inline (vm, node, frame, vif, type,
654 1 /* checksum offload */ ,
655 vif->packet_coalesce);
656 else if (hw->flags & VNET_HW_INTERFACE_FLAG_SUPPORTS_TX_L4_CKSUM_OFFLOAD)
657 return virtio_interface_tx_gso_inline (vm, node, frame, vif, type,
659 1 /* checksum offload */ ,
662 return virtio_interface_tx_gso_inline (vm, node, frame, vif, type,
664 0 /* no checksum offload */ ,
668 VNET_DEVICE_CLASS_TX_FN (virtio_device_class) (vlib_main_t * vm,
669 vlib_node_runtime_t * node,
670 vlib_frame_t * frame)
672 virtio_main_t *nm = &virtio_main;
673 vnet_interface_output_runtime_t *rund = (void *) node->runtime_data;
674 virtio_if_t *vif = pool_elt_at_index (nm->interfaces, rund->dev_instance);
676 if (vif->type == VIRTIO_IF_TYPE_TAP)
677 return virtio_interface_tx_inline (vm, node, frame, vif,
679 else if (vif->type == VIRTIO_IF_TYPE_PCI)
680 return virtio_interface_tx_inline (vm, node, frame, vif,
682 else if (vif->type == VIRTIO_IF_TYPE_TUN)
683 return virtio_interface_tx_inline (vm, node, frame, vif,
692 virtio_set_interface_next_node (vnet_main_t * vnm, u32 hw_if_index,
695 virtio_main_t *apm = &virtio_main;
696 vnet_hw_interface_t *hw = vnet_get_hw_interface (vnm, hw_if_index);
697 virtio_if_t *vif = pool_elt_at_index (apm->interfaces, hw->dev_instance);
699 /* Shut off redirection */
700 if (node_index == ~0)
702 vif->per_interface_next_index = node_index;
706 vif->per_interface_next_index =
707 vlib_node_add_next (vlib_get_main (), virtio_input_node.index,
712 virtio_clear_hw_interface_counters (u32 instance)
714 /* Nothing for now */
717 static clib_error_t *
718 virtio_interface_rx_mode_change (vnet_main_t * vnm, u32 hw_if_index, u32 qid,
719 vnet_hw_interface_rx_mode mode)
721 virtio_main_t *mm = &virtio_main;
722 vnet_hw_interface_t *hw = vnet_get_hw_interface (vnm, hw_if_index);
723 virtio_if_t *vif = pool_elt_at_index (mm->interfaces, hw->dev_instance);
724 virtio_vring_t *vring = vec_elt_at_index (vif->rxq_vrings, qid);
726 if (vif->type == VIRTIO_IF_TYPE_PCI && !(vif->support_int_mode))
728 vring->avail->flags |= VRING_AVAIL_F_NO_INTERRUPT;
729 return clib_error_return (0, "interrupt mode is not supported");
732 if (mode == VNET_HW_INTERFACE_RX_MODE_POLLING)
734 /* only enable packet coalesce in poll mode */
735 gro_flow_table_set_is_enable (vring->flow_table, 1);
736 vring->avail->flags |= VRING_AVAIL_F_NO_INTERRUPT;
740 gro_flow_table_set_is_enable (vring->flow_table, 0);
741 vring->avail->flags &= ~VRING_AVAIL_F_NO_INTERRUPT;
747 static clib_error_t *
748 virtio_interface_admin_up_down (vnet_main_t * vnm, u32 hw_if_index, u32 flags)
750 virtio_main_t *mm = &virtio_main;
751 vnet_hw_interface_t *hw = vnet_get_hw_interface (vnm, hw_if_index);
752 virtio_if_t *vif = pool_elt_at_index (mm->interfaces, hw->dev_instance);
754 if (flags & VNET_SW_INTERFACE_FLAG_ADMIN_UP)
756 vif->flags |= VIRTIO_IF_FLAG_ADMIN_UP;
757 vnet_hw_interface_set_flags (vnm, vif->hw_if_index,
758 VNET_HW_INTERFACE_FLAG_LINK_UP);
762 vif->flags &= ~VIRTIO_IF_FLAG_ADMIN_UP;
763 vnet_hw_interface_set_flags (vnm, vif->hw_if_index, 0);
768 static clib_error_t *
769 virtio_subif_add_del_function (vnet_main_t * vnm,
771 struct vnet_sw_interface_t *st, int is_add)
773 /* Nothing for now */
778 VNET_DEVICE_CLASS (virtio_device_class) = {
780 .format_device_name = format_virtio_device_name,
781 .format_device = format_virtio_device,
782 .format_tx_trace = format_virtio_tx_trace,
783 .tx_function_n_errors = VIRTIO_TX_N_ERROR,
784 .tx_function_error_strings = virtio_tx_func_error_strings,
785 .rx_redirect_to_node = virtio_set_interface_next_node,
786 .clear_counters = virtio_clear_hw_interface_counters,
787 .admin_up_down_function = virtio_interface_admin_up_down,
788 .subif_add_del_function = virtio_subif_add_del_function,
789 .rx_mode_change_function = virtio_interface_rx_mode_change,
795 * fd.io coding-style-patch-verification: ON
798 * eval: (c-set-style "gnu")