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/gso.h>
27 #include <vnet/ip/ip4_packet.h>
28 #include <vnet/ip/ip6_packet.h>
29 #include <vnet/tcp/tcp_packet.h>
30 #include <vnet/udp/udp_packet.h>
31 #include <vnet/devices/virtio/virtio.h>
33 #define foreach_virtio_tx_func_error \
34 _(NO_FREE_SLOTS, "no free tx slots") \
35 _(TRUNC_PACKET, "packet > buffer size -- truncated in tx ring") \
36 _(PENDING_MSGS, "pending msgs in tx ring") \
37 _(INDIRECT_DESC_ALLOC_FAILED, "indirect descriptor allocation failed - packet drop") \
38 _(OUT_OF_ORDER, "out-of-order buffers in used ring") \
39 _(GSO_PACKET_DROP, "gso disabled on itf -- gso packet drop") \
40 _(CSUM_OFFLOAD_PACKET_DROP, "checksum offload disabled on itf -- csum offload packet drop")
44 #define _(f,s) VIRTIO_TX_ERROR_##f,
45 foreach_virtio_tx_func_error
48 } virtio_tx_func_error_t;
50 static char *virtio_tx_func_error_strings[] = {
52 foreach_virtio_tx_func_error
57 format_virtio_device (u8 * s, va_list * args)
59 u32 dev_instance = va_arg (*args, u32);
60 int verbose = va_arg (*args, int);
61 u32 indent = format_get_indent (s);
63 s = format (s, "VIRTIO interface");
66 s = format (s, "\n%U instance %u", format_white_space, indent + 2,
73 format_virtio_tx_trace (u8 * s, va_list * args)
75 s = format (s, "Unimplemented...");
79 static_always_inline void
80 virtio_interface_drop_inline (vlib_main_t * vm, uword node_index,
82 virtio_tx_func_error_t error)
84 vlib_error_count (vm, node_index, error, n);
85 vlib_buffer_free (vm, buffers, n);
88 static_always_inline void
89 virtio_memset_ring_u32 (u32 * ring, u32 start, u32 ring_size, u32 n_buffers)
91 ASSERT (n_buffers <= ring_size);
93 if (PREDICT_TRUE (start + n_buffers <= ring_size))
95 clib_memset_u32 (ring + start, ~0, n_buffers);
99 clib_memset_u32 (ring + start, ~0, ring_size - start);
100 clib_memset_u32 (ring, ~0, n_buffers - (ring_size - start));
104 static_always_inline void
105 virtio_free_used_device_desc (vlib_main_t * vm, virtio_vring_t * vring,
108 u16 used = vring->desc_in_use;
109 u16 sz = vring->size;
111 u16 last = vring->last_used_idx;
112 u16 n_left = vring->used->idx - last;
113 u16 out_of_order_count = 0;
120 struct vring_used_elem *e = &vring->used->ring[last & mask];
122 slot = n_buffers = e->id;
124 while (e->id == (n_buffers & mask))
129 struct vring_desc *d = &vring->desc[e->id];
131 while (d->flags & VRING_DESC_F_NEXT)
135 d = &vring->desc[next];
139 e = &vring->used->ring[last & mask];
141 vlib_buffer_free_from_ring (vm, vring->buffers, slot,
142 sz, (n_buffers - slot));
143 virtio_memset_ring_u32 (vring->buffers, slot, sz, (n_buffers - slot));
144 used -= (n_buffers - slot);
148 vlib_buffer_free (vm, &vring->buffers[e->id], 1);
149 vring->buffers[e->id] = ~0;
153 out_of_order_count++;
154 vring->flags |= VRING_TX_OUT_OF_ORDER;
159 * Some vhost-backends give buffers back in out-of-order fashion in used ring.
160 * It impacts the overall virtio-performance.
162 if (out_of_order_count)
163 vlib_error_count (vm, node_index, VIRTIO_TX_ERROR_OUT_OF_ORDER,
166 vring->desc_in_use = used;
167 vring->last_used_idx = last;
170 static_always_inline void
171 set_checksum_offsets (vlib_buffer_t * b, struct virtio_net_hdr_v1 *hdr)
173 if (b->flags & VNET_BUFFER_F_IS_IP4)
176 gso_header_offset_t gho = vnet_gso_header_offset_parser (b, 0);
177 hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
178 hdr->csum_start = gho.l4_hdr_offset; // 0x22;
179 if (b->flags & VNET_BUFFER_F_OFFLOAD_TCP_CKSUM)
181 hdr->csum_offset = STRUCT_OFFSET_OF (tcp_header_t, checksum);
183 else if (b->flags & VNET_BUFFER_F_OFFLOAD_UDP_CKSUM)
185 hdr->csum_offset = STRUCT_OFFSET_OF (udp_header_t, checksum);
189 * virtio devices do not support IP4 checksum offload. So driver takes care
190 * of it while doing tx.
193 (ip4_header_t *) (vlib_buffer_get_current (b) + gho.l3_hdr_offset);
194 if (b->flags & VNET_BUFFER_F_OFFLOAD_IP_CKSUM)
195 ip4->checksum = ip4_header_checksum (ip4);
197 else if (b->flags & VNET_BUFFER_F_IS_IP6)
199 gso_header_offset_t gho = vnet_gso_header_offset_parser (b, 1);
200 hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
201 hdr->csum_start = gho.l4_hdr_offset; // 0x36;
202 if (b->flags & VNET_BUFFER_F_OFFLOAD_TCP_CKSUM)
204 hdr->csum_offset = STRUCT_OFFSET_OF (tcp_header_t, checksum);
206 else if (b->flags & VNET_BUFFER_F_OFFLOAD_UDP_CKSUM)
208 hdr->csum_offset = STRUCT_OFFSET_OF (udp_header_t, checksum);
213 static_always_inline void
214 set_gso_offsets (vlib_buffer_t * b, struct virtio_net_hdr_v1 *hdr)
216 if (b->flags & VNET_BUFFER_F_IS_IP4)
219 gso_header_offset_t gho = vnet_gso_header_offset_parser (b, 0);
220 hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
221 hdr->gso_size = vnet_buffer2 (b)->gso_size;
222 hdr->hdr_len = gho.l4_hdr_offset + gho.l4_hdr_sz;
223 hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
224 hdr->csum_start = gho.l4_hdr_offset; // 0x22;
225 hdr->csum_offset = STRUCT_OFFSET_OF (tcp_header_t, checksum);
227 (ip4_header_t *) (vlib_buffer_get_current (b) + gho.l3_hdr_offset);
229 * virtio devices do not support IP4 checksum offload. So driver takes care
230 * of it while doing tx.
232 if (b->flags & VNET_BUFFER_F_OFFLOAD_IP_CKSUM)
233 ip4->checksum = ip4_header_checksum (ip4);
235 else if (b->flags & VNET_BUFFER_F_IS_IP6)
237 gso_header_offset_t gho = vnet_gso_header_offset_parser (b, 1);
238 hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
239 hdr->gso_size = vnet_buffer2 (b)->gso_size;
240 hdr->hdr_len = gho.l4_hdr_offset + gho.l4_hdr_sz;
241 hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
242 hdr->csum_start = gho.l4_hdr_offset; // 0x36;
243 hdr->csum_offset = STRUCT_OFFSET_OF (tcp_header_t, checksum);
247 static_always_inline u16
248 add_buffer_to_slot (vlib_main_t * vm, virtio_if_t * vif,
249 virtio_vring_t * vring, u32 bi, u16 free_desc_count,
250 u16 avail, u16 next, u16 mask, int do_gso,
251 int csum_offload, uword node_index)
254 int hdr_sz = vif->virtio_net_hdr_sz;
255 struct vring_desc *d;
256 d = &vring->desc[next];
257 vlib_buffer_t *b = vlib_get_buffer (vm, bi);
258 struct virtio_net_hdr_v1 *hdr = vlib_buffer_get_current (b) - hdr_sz;
260 clib_memset (hdr, 0, hdr_sz);
262 if (b->flags & VNET_BUFFER_F_GSO)
265 set_gso_offsets (b, hdr);
268 virtio_interface_drop_inline (vm, node_index, &bi, 1,
269 VIRTIO_TX_ERROR_GSO_PACKET_DROP);
273 else if (b->flags & (VNET_BUFFER_F_OFFLOAD_TCP_CKSUM |
274 VNET_BUFFER_F_OFFLOAD_UDP_CKSUM))
277 set_checksum_offsets (b, hdr);
280 virtio_interface_drop_inline (vm, node_index, &bi, 1,
281 VIRTIO_TX_ERROR_CSUM_OFFLOAD_PACKET_DROP);
286 if (PREDICT_TRUE ((b->flags & VLIB_BUFFER_NEXT_PRESENT) == 0))
289 ((vif->type == VIRTIO_IF_TYPE_PCI) ? vlib_buffer_get_current_pa (vm,
291 pointer_to_uword (vlib_buffer_get_current (b))) - hdr_sz;
292 d->len = b->current_length + hdr_sz;
295 else if (vif->features & VIRTIO_FEATURE (VIRTIO_RING_F_INDIRECT_DESC))
298 * We are using single vlib_buffer_t for indirect descriptor(s)
299 * chain. Single descriptor is 16 bytes and vlib_buffer_t
300 * has 2048 bytes space. So maximum long chain can have 128
301 * (=2048/16) indirect descriptors.
302 * It can easily support 65535 bytes of Jumbo frames with
303 * each data buffer size of 512 bytes minimum.
305 u32 indirect_buffer = 0;
306 if (PREDICT_FALSE (vlib_buffer_alloc (vm, &indirect_buffer, 1) == 0))
308 virtio_interface_drop_inline (vm, node_index, &bi, 1,
309 VIRTIO_TX_ERROR_INDIRECT_DESC_ALLOC_FAILED);
313 vlib_buffer_t *indirect_desc = vlib_get_buffer (vm, indirect_buffer);
314 indirect_desc->current_data = 0;
315 indirect_desc->flags |= VLIB_BUFFER_NEXT_PRESENT;
316 indirect_desc->next_buffer = bi;
317 bi = indirect_buffer;
319 struct vring_desc *id =
320 (struct vring_desc *) vlib_buffer_get_current (indirect_desc);
322 if (vif->type == VIRTIO_IF_TYPE_PCI)
324 d->addr = vlib_physmem_get_pa (vm, id);
325 id->addr = vlib_buffer_get_current_pa (vm, b) - hdr_sz;
328 * If VIRTIO_F_ANY_LAYOUT is not negotiated, then virtio_net_hdr
329 * should be presented in separate descriptor and data will start
330 * from next descriptor.
333 (vif->features & VIRTIO_FEATURE (VIRTIO_F_ANY_LAYOUT)))
334 id->len = b->current_length + hdr_sz;
338 id->flags = VRING_DESC_F_NEXT;
342 id->addr = vlib_buffer_get_current_pa (vm, b);
343 id->len = b->current_length;
345 while (b->flags & VLIB_BUFFER_NEXT_PRESENT)
347 id->flags = VRING_DESC_F_NEXT;
351 b = vlib_get_buffer (vm, b->next_buffer);
352 id->addr = vlib_buffer_get_current_pa (vm, b);
353 id->len = b->current_length;
356 else /* VIRTIO_IF_TYPE_[TAP | TUN] */
358 d->addr = pointer_to_uword (id);
359 /* first buffer in chain */
360 id->addr = pointer_to_uword (vlib_buffer_get_current (b)) - hdr_sz;
361 id->len = b->current_length + hdr_sz;
363 while (b->flags & VLIB_BUFFER_NEXT_PRESENT)
365 id->flags = VRING_DESC_F_NEXT;
369 b = vlib_get_buffer (vm, b->next_buffer);
370 id->addr = pointer_to_uword (vlib_buffer_get_current (b));
371 id->len = b->current_length;
376 d->len = count * sizeof (struct vring_desc);
377 d->flags = VRING_DESC_F_INDIRECT;
379 else if (vif->type == VIRTIO_IF_TYPE_PCI)
382 vlib_buffer_t *b_temp = b;
383 u16 n_buffers_in_chain = 1;
386 * Check the length of the chain for the required number of
387 * descriptors. Return from here, retry to get more descriptors,
388 * if chain length is greater than available descriptors.
390 while (b_temp->flags & VLIB_BUFFER_NEXT_PRESENT)
392 n_buffers_in_chain++;
393 b_temp = vlib_get_buffer (vm, b_temp->next_buffer);
396 if (n_buffers_in_chain > free_desc_count)
397 return n_buffers_in_chain;
399 d->addr = vlib_buffer_get_current_pa (vm, b) - hdr_sz;
400 d->len = b->current_length + hdr_sz;
402 while (b->flags & VLIB_BUFFER_NEXT_PRESENT)
404 d->flags = VRING_DESC_F_NEXT;
405 vring->buffers[count] = bi;
407 ~(VLIB_BUFFER_NEXT_PRESENT | VLIB_BUFFER_TOTAL_LENGTH_VALID);
411 count = (count + 1) & mask;
413 d = &vring->desc[count];
414 b = vlib_get_buffer (vm, bi);
415 d->addr = vlib_buffer_get_current_pa (vm, b);
416 d->len = b->current_length;
419 vring->buffers[count] = bi;
420 vring->avail->ring[avail & mask] = next;
428 vring->buffers[next] = bi;
429 vring->avail->ring[avail & mask] = next;
434 static_always_inline void
435 virtio_find_free_desc (virtio_vring_t * vring, u16 size, u16 mask,
436 u16 req, u16 next, u32 * first_free_desc_index,
437 u16 * free_desc_count)
440 /* next is used as hint: from where to start looking */
441 for (u16 i = 0; i < size; i++, next++)
443 if (vring->buffers[next & mask] == ~0)
445 if (*first_free_desc_index == ~0)
447 *first_free_desc_index = (next & mask);
449 (*free_desc_count)++;
456 if (start + *free_desc_count == i)
458 (*free_desc_count)++;
470 static_always_inline uword
471 virtio_interface_tx_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
472 vlib_frame_t * frame, virtio_if_t * vif,
473 int do_gso, int csum_offload)
475 u16 n_left = frame->n_vectors;
476 virtio_vring_t *vring;
477 u16 qid = vm->thread_index % vif->num_txqs;
478 vring = vec_elt_at_index (vif->txq_vrings, qid);
479 u16 used, next, avail;
480 u16 sz = vring->size;
483 u32 *buffers = vlib_frame_vector_args (frame);
485 clib_spinlock_lock_if_init (&vring->lockp);
487 if ((vring->used->flags & VIRTIO_RING_FLAG_MASK_INT) == 0 &&
488 (vring->last_kick_avail_idx != vring->avail->idx))
489 virtio_kick (vm, vring, vif);
492 /* free consumed buffers */
493 virtio_free_used_device_desc (vm, vring, node->node_index);
495 used = vring->desc_in_use;
496 next = vring->desc_next;
497 avail = vring->avail->idx;
499 u16 free_desc_count = 0;
501 if (PREDICT_FALSE (vring->flags & VRING_TX_OUT_OF_ORDER))
503 u32 first_free_desc_index = ~0;
505 virtio_find_free_desc (vring, sz, mask, n_left, next,
506 &first_free_desc_index, &free_desc_count);
509 next = first_free_desc_index;
512 free_desc_count = sz - used;
514 while (n_left && free_desc_count)
518 add_buffer_to_slot (vm, vif, vring, buffers[0], free_desc_count,
519 avail, next, mask, do_gso, csum_offload,
522 if (PREDICT_FALSE (n_added == 0))
528 else if (PREDICT_FALSE (n_added > free_desc_count))
532 next = (next + n_added) & mask;
536 free_desc_count -= n_added;
539 if (n_left != frame->n_vectors)
541 CLIB_MEMORY_STORE_BARRIER ();
542 vring->avail->idx = avail;
543 vring->desc_next = next;
544 vring->desc_in_use = used;
545 if ((vring->used->flags & VIRTIO_RING_FLAG_MASK_INT) == 0)
546 virtio_kick (vm, vring, vif);
554 virtio_interface_drop_inline (vm, node->node_index, buffers, n_left,
555 VIRTIO_TX_ERROR_NO_FREE_SLOTS);
558 clib_spinlock_unlock_if_init (&vring->lockp);
560 return frame->n_vectors - n_left;
563 VNET_DEVICE_CLASS_TX_FN (virtio_device_class) (vlib_main_t * vm,
564 vlib_node_runtime_t * node,
565 vlib_frame_t * frame)
567 vnet_main_t *vnm = vnet_get_main ();
568 virtio_main_t *nm = &virtio_main;
569 vnet_interface_output_runtime_t *rund = (void *) node->runtime_data;
570 virtio_if_t *vif = pool_elt_at_index (nm->interfaces, rund->dev_instance);
571 vnet_hw_interface_t *hw = vnet_get_hw_interface (vnm, vif->hw_if_index);
573 if (hw->flags & VNET_HW_INTERFACE_FLAG_SUPPORTS_GSO)
574 return virtio_interface_tx_inline (vm, node, frame, vif, 1 /* do_gso */ ,
576 else if (hw->flags & VNET_HW_INTERFACE_FLAG_SUPPORTS_TX_L4_CKSUM_OFFLOAD)
577 return virtio_interface_tx_inline (vm, node, frame, vif,
578 0 /* no do_gso */ , 1);
580 return virtio_interface_tx_inline (vm, node, frame, vif,
581 0 /* no do_gso */ , 0);
585 virtio_set_interface_next_node (vnet_main_t * vnm, u32 hw_if_index,
588 virtio_main_t *apm = &virtio_main;
589 vnet_hw_interface_t *hw = vnet_get_hw_interface (vnm, hw_if_index);
590 virtio_if_t *vif = pool_elt_at_index (apm->interfaces, hw->dev_instance);
592 /* Shut off redirection */
593 if (node_index == ~0)
595 vif->per_interface_next_index = node_index;
599 vif->per_interface_next_index =
600 vlib_node_add_next (vlib_get_main (), virtio_input_node.index,
605 virtio_clear_hw_interface_counters (u32 instance)
607 /* Nothing for now */
610 static clib_error_t *
611 virtio_interface_rx_mode_change (vnet_main_t * vnm, u32 hw_if_index, u32 qid,
612 vnet_hw_interface_rx_mode mode)
614 virtio_main_t *mm = &virtio_main;
615 vnet_hw_interface_t *hw = vnet_get_hw_interface (vnm, hw_if_index);
616 virtio_if_t *vif = pool_elt_at_index (mm->interfaces, hw->dev_instance);
617 virtio_vring_t *vring = vec_elt_at_index (vif->rxq_vrings, qid);
619 if (vif->type == VIRTIO_IF_TYPE_PCI && !(vif->support_int_mode))
621 vring->avail->flags |= VIRTIO_RING_FLAG_MASK_INT;
622 return clib_error_return (0, "interrupt mode is not supported");
625 if (mode == VNET_HW_INTERFACE_RX_MODE_POLLING)
626 vring->avail->flags |= VIRTIO_RING_FLAG_MASK_INT;
628 vring->avail->flags &= ~VIRTIO_RING_FLAG_MASK_INT;
633 static clib_error_t *
634 virtio_interface_admin_up_down (vnet_main_t * vnm, u32 hw_if_index, u32 flags)
636 virtio_main_t *mm = &virtio_main;
637 vnet_hw_interface_t *hw = vnet_get_hw_interface (vnm, hw_if_index);
638 virtio_if_t *vif = pool_elt_at_index (mm->interfaces, hw->dev_instance);
640 if (flags & VNET_SW_INTERFACE_FLAG_ADMIN_UP)
642 vif->flags |= VIRTIO_IF_FLAG_ADMIN_UP;
643 vnet_hw_interface_set_flags (vnm, vif->hw_if_index,
644 VNET_HW_INTERFACE_FLAG_LINK_UP);
648 vif->flags &= ~VIRTIO_IF_FLAG_ADMIN_UP;
649 vnet_hw_interface_set_flags (vnm, vif->hw_if_index, 0);
654 static clib_error_t *
655 virtio_subif_add_del_function (vnet_main_t * vnm,
657 struct vnet_sw_interface_t *st, int is_add)
659 /* Nothing for now */
664 VNET_DEVICE_CLASS (virtio_device_class) = {
666 .format_device_name = format_virtio_device_name,
667 .format_device = format_virtio_device,
668 .format_tx_trace = format_virtio_tx_trace,
669 .tx_function_n_errors = VIRTIO_TX_N_ERROR,
670 .tx_function_error_strings = virtio_tx_func_error_strings,
671 .rx_redirect_to_node = virtio_set_interface_next_node,
672 .clear_counters = virtio_clear_hw_interface_counters,
673 .admin_up_down_function = virtio_interface_admin_up_down,
674 .subif_add_del_function = virtio_subif_add_del_function,
675 .rx_mode_change_function = virtio_interface_rx_mode_change,
681 * fd.io coding-style-patch-verification: ON
684 * eval: (c-set-style "gnu")