2 *------------------------------------------------------------------
5 * Copyright (c) 2014-2018 Cisco and/or its affiliates.
6 * Licensed under the Apache License, Version 2.0 (the "License");
7 * you may not use this file except in compliance with the License.
8 * You may obtain a copy of the License at:
10 * http://www.apache.org/licenses/LICENSE-2.0
12 * Unless required by applicable law or agreed to in writing, software
13 * distributed under the License is distributed on an "AS IS" BASIS,
14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15 * See the License for the specific language governing permissions and
16 * limitations under the License.
17 *------------------------------------------------------------------
21 #include <fcntl.h> /* for open */
22 #include <sys/ioctl.h>
23 #include <sys/socket.h>
26 #include <sys/types.h>
27 #include <sys/uio.h> /* for iovec */
28 #include <netinet/in.h>
31 #include <linux/if_arp.h>
32 #include <linux/if_tun.h>
34 #include <vlib/vlib.h>
35 #include <vlib/unix/unix.h>
37 #include <vnet/ip/ip.h>
39 #include <vnet/ethernet/ethernet.h>
40 #include <vnet/devices/devices.h>
41 #include <vnet/feature/feature.h>
43 #include <vnet/devices/virtio/virtio.h>
44 #include <vnet/devices/virtio/vhost_user.h>
45 #include <vnet/devices/virtio/vhost_user_inline.h>
47 #include <vnet/gso/hdr_offset_parser.h>
49 * On the transmit side, we keep processing the buffers from vlib in the while
50 * loop and prepare the copy order to be executed later. However, the static
51 * array which we keep the copy order is limited to VHOST_USER_COPY_ARRAY_N
52 * entries. In order to not corrupt memory, we have to do the copy when the
53 * static array reaches the copy threshold. We subtract 40 in case the code
54 * goes into the inner loop for a maximum of 64k frames which may require
55 * more array entries. We subtract 200 because our default buffer size is
56 * 2048 and the default desc len is likely 1536. While it takes less than 40
57 * vlib buffers for the jumbo frame, it may take twice as much descriptors
58 * for the same jumbo frame. Use 200 for the extra head room.
60 #define VHOST_USER_TX_COPY_THRESHOLD (VHOST_USER_COPY_ARRAY_N - 200)
62 extern vnet_device_class_t vhost_user_device_class;
64 #define foreach_vhost_user_tx_func_error \
66 _(NOT_READY, "vhost vring not ready") \
67 _(DOWN, "vhost interface is down") \
68 _(PKT_DROP_NOBUF, "tx packet drops (no available descriptors)") \
69 _(PKT_DROP_NOMRG, "tx packet drops (cannot merge descriptors)") \
70 _(MMAP_FAIL, "mmap failure") \
71 _(INDIRECT_OVERFLOW, "indirect descriptor table overflow")
75 #define _(f,s) VHOST_USER_TX_FUNC_ERROR_##f,
76 foreach_vhost_user_tx_func_error
78 VHOST_USER_TX_FUNC_N_ERROR,
79 } vhost_user_tx_func_error_t;
81 static __clib_unused char *vhost_user_tx_func_error_strings[] = {
83 foreach_vhost_user_tx_func_error
87 static __clib_unused u8 *
88 format_vhost_user_interface_name (u8 * s, va_list * args)
90 u32 i = va_arg (*args, u32);
91 u32 show_dev_instance = ~0;
92 vhost_user_main_t *vum = &vhost_user_main;
94 if (i < vec_len (vum->show_dev_instance_by_real_dev_instance))
95 show_dev_instance = vum->show_dev_instance_by_real_dev_instance[i];
97 if (show_dev_instance != ~0)
98 i = show_dev_instance;
100 s = format (s, "VirtualEthernet0/0/%d", i);
104 static __clib_unused int
105 vhost_user_name_renumber (vnet_hw_interface_t * hi, u32 new_dev_instance)
107 // FIXME: check if the new dev instance is already used
108 vhost_user_main_t *vum = &vhost_user_main;
109 vhost_user_intf_t *vui = pool_elt_at_index (vum->vhost_user_interfaces,
112 vec_validate_init_empty (vum->show_dev_instance_by_real_dev_instance,
113 hi->dev_instance, ~0);
115 vum->show_dev_instance_by_real_dev_instance[hi->dev_instance] =
118 vu_log_debug (vui, "renumbered vhost-user interface dev_instance %d to %d",
119 hi->dev_instance, new_dev_instance);
125 * @brief Try once to lock the vring
126 * @return 0 on success, non-zero on failure.
128 static_always_inline int
129 vhost_user_vring_try_lock (vhost_user_intf_t * vui, u32 qid)
131 return clib_atomic_test_and_set (vui->vring_locks[qid]);
135 * @brief Spin until the vring is successfully locked
137 static_always_inline void
138 vhost_user_vring_lock (vhost_user_intf_t * vui, u32 qid)
140 while (vhost_user_vring_try_lock (vui, qid))
145 * @brief Unlock the vring lock
147 static_always_inline void
148 vhost_user_vring_unlock (vhost_user_intf_t * vui, u32 qid)
150 clib_atomic_release (vui->vring_locks[qid]);
153 static_always_inline void
154 vhost_user_tx_trace (vhost_trace_t * t,
155 vhost_user_intf_t * vui, u16 qid,
156 vlib_buffer_t * b, vhost_user_vring_t * rxvq)
158 vhost_user_main_t *vum = &vhost_user_main;
159 u32 last_avail_idx = rxvq->last_avail_idx;
160 u32 desc_current = rxvq->avail->ring[last_avail_idx & rxvq->qsz_mask];
161 vring_desc_t *hdr_desc = 0;
164 clib_memset (t, 0, sizeof (*t));
165 t->device_index = vui - vum->vhost_user_interfaces;
168 hdr_desc = &rxvq->desc[desc_current];
169 if (rxvq->desc[desc_current].flags & VIRTQ_DESC_F_INDIRECT)
171 t->virtio_ring_flags |= 1 << VIRTIO_TRACE_F_INDIRECT;
172 /* Header is the first here */
173 hdr_desc = map_guest_mem (vui, rxvq->desc[desc_current].addr, &hint);
175 if (rxvq->desc[desc_current].flags & VIRTQ_DESC_F_NEXT)
177 t->virtio_ring_flags |= 1 << VIRTIO_TRACE_F_SIMPLE_CHAINED;
179 if (!(rxvq->desc[desc_current].flags & VIRTQ_DESC_F_NEXT) &&
180 !(rxvq->desc[desc_current].flags & VIRTQ_DESC_F_INDIRECT))
182 t->virtio_ring_flags |= 1 << VIRTIO_TRACE_F_SINGLE_DESC;
185 t->first_desc_len = hdr_desc ? hdr_desc->len : 0;
188 static_always_inline u32
189 vhost_user_tx_copy (vhost_user_intf_t * vui, vhost_copy_t * cpy,
190 u16 copy_len, u32 * map_hint)
192 void *dst0, *dst1, *dst2, *dst3;
193 if (PREDICT_TRUE (copy_len >= 4))
195 if (PREDICT_FALSE (!(dst2 = map_guest_mem (vui, cpy[0].dst, map_hint))))
197 if (PREDICT_FALSE (!(dst3 = map_guest_mem (vui, cpy[1].dst, map_hint))))
199 while (PREDICT_TRUE (copy_len >= 4))
205 (!(dst2 = map_guest_mem (vui, cpy[2].dst, map_hint))))
208 (!(dst3 = map_guest_mem (vui, cpy[3].dst, map_hint))))
211 CLIB_PREFETCH ((void *) cpy[2].src, 64, LOAD);
212 CLIB_PREFETCH ((void *) cpy[3].src, 64, LOAD);
214 clib_memcpy_fast (dst0, (void *) cpy[0].src, cpy[0].len);
215 clib_memcpy_fast (dst1, (void *) cpy[1].src, cpy[1].len);
217 vhost_user_log_dirty_pages_2 (vui, cpy[0].dst, cpy[0].len, 1);
218 vhost_user_log_dirty_pages_2 (vui, cpy[1].dst, cpy[1].len, 1);
225 if (PREDICT_FALSE (!(dst0 = map_guest_mem (vui, cpy->dst, map_hint))))
227 clib_memcpy_fast (dst0, (void *) cpy->src, cpy->len);
228 vhost_user_log_dirty_pages_2 (vui, cpy->dst, cpy->len, 1);
235 static_always_inline void
236 vhost_user_handle_tx_offload (vhost_user_intf_t * vui, vlib_buffer_t * b,
237 virtio_net_hdr_t * hdr)
239 generic_header_offset_t gho = { 0 };
240 vnet_generic_header_offset_parser (b, &gho);
241 if (b->flags & VNET_BUFFER_F_OFFLOAD_IP_CKSUM)
246 (ip4_header_t *) (vlib_buffer_get_current (b) + gho.l3_hdr_offset);
247 ip4->checksum = ip4_header_checksum (ip4);
250 /* checksum offload */
251 if (b->flags & VNET_BUFFER_F_OFFLOAD_UDP_CKSUM)
253 hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
254 hdr->csum_start = gho.l4_hdr_offset;
255 hdr->csum_offset = offsetof (udp_header_t, checksum);
257 (udp_header_t *) (vlib_buffer_get_current (b) + gho.l4_hdr_offset);
260 else if (b->flags & VNET_BUFFER_F_OFFLOAD_TCP_CKSUM)
262 hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
263 hdr->csum_start = gho.l4_hdr_offset;
264 hdr->csum_offset = offsetof (tcp_header_t, checksum);
266 (tcp_header_t *) (vlib_buffer_get_current (b) + gho.l4_hdr_offset);
271 if (b->flags & VNET_BUFFER_F_GSO)
273 if (b->flags & VNET_BUFFER_F_OFFLOAD_TCP_CKSUM)
275 if ((b->flags & VNET_BUFFER_F_IS_IP4) &&
276 (vui->features & (1ULL << FEAT_VIRTIO_NET_F_GUEST_TSO4)))
278 hdr->gso_size = vnet_buffer2 (b)->gso_size;
279 hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
281 else if ((b->flags & VNET_BUFFER_F_IS_IP6) &&
282 (vui->features & (1ULL << FEAT_VIRTIO_NET_F_GUEST_TSO6)))
284 hdr->gso_size = vnet_buffer2 (b)->gso_size;
285 hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
288 else if ((vui->features & (1ULL << FEAT_VIRTIO_NET_F_GUEST_UFO)) &&
289 (b->flags & VNET_BUFFER_F_OFFLOAD_UDP_CKSUM))
291 hdr->gso_size = vnet_buffer2 (b)->gso_size;
292 hdr->gso_type = VIRTIO_NET_HDR_GSO_UDP;
297 static_always_inline void
298 vhost_user_mark_desc_available (vlib_main_t * vm, vhost_user_vring_t * rxvq,
299 u16 * n_descs_processed, u8 chained,
300 vlib_frame_t * frame, u32 n_left)
303 vring_packed_desc_t *desc_table = rxvq->packed_desc;
304 u16 last_used_idx = rxvq->last_used_idx;
306 if (PREDICT_FALSE (*n_descs_processed == 0))
309 if (rxvq->used_wrap_counter)
310 flags = desc_table[last_used_idx & rxvq->qsz_mask].flags |
311 (VIRTQ_DESC_F_AVAIL | VIRTQ_DESC_F_USED);
313 flags = desc_table[last_used_idx & rxvq->qsz_mask].flags &
314 ~(VIRTQ_DESC_F_AVAIL | VIRTQ_DESC_F_USED);
316 vhost_user_advance_last_used_idx (rxvq);
318 for (desc_idx = 1; desc_idx < *n_descs_processed; desc_idx++)
320 if (rxvq->used_wrap_counter)
321 desc_table[rxvq->last_used_idx & rxvq->qsz_mask].flags |=
322 (VIRTQ_DESC_F_AVAIL | VIRTQ_DESC_F_USED);
324 desc_table[rxvq->last_used_idx & rxvq->qsz_mask].flags &=
325 ~(VIRTQ_DESC_F_AVAIL | VIRTQ_DESC_F_USED);
326 vhost_user_advance_last_used_idx (rxvq);
329 desc_table[last_used_idx & rxvq->qsz_mask].flags = flags;
331 *n_descs_processed = 0;
335 vring_packed_desc_t *desc_table = rxvq->packed_desc;
337 while (desc_table[rxvq->last_used_idx & rxvq->qsz_mask].flags &
339 vhost_user_advance_last_used_idx (rxvq);
341 /* Advance past the current chained table entries */
342 vhost_user_advance_last_used_idx (rxvq);
345 /* interrupt (call) handling */
346 if ((rxvq->callfd_idx != ~0) &&
347 (rxvq->avail_event->flags != VRING_EVENT_F_DISABLE))
349 vhost_user_main_t *vum = &vhost_user_main;
351 rxvq->n_since_last_int += frame->n_vectors - n_left;
352 if (rxvq->n_since_last_int > vum->coalesce_frames)
353 vhost_user_send_call (vm, rxvq);
357 static_always_inline void
358 vhost_user_tx_trace_packed (vhost_trace_t * t, vhost_user_intf_t * vui,
359 u16 qid, vlib_buffer_t * b,
360 vhost_user_vring_t * rxvq)
362 vhost_user_main_t *vum = &vhost_user_main;
363 u32 last_avail_idx = rxvq->last_avail_idx;
364 u32 desc_current = last_avail_idx & rxvq->qsz_mask;
365 vring_packed_desc_t *hdr_desc = 0;
368 clib_memset (t, 0, sizeof (*t));
369 t->device_index = vui - vum->vhost_user_interfaces;
372 hdr_desc = &rxvq->packed_desc[desc_current];
373 if (rxvq->packed_desc[desc_current].flags & VIRTQ_DESC_F_INDIRECT)
375 t->virtio_ring_flags |= 1 << VIRTIO_TRACE_F_INDIRECT;
376 /* Header is the first here */
377 hdr_desc = map_guest_mem (vui, rxvq->packed_desc[desc_current].addr,
380 if (rxvq->packed_desc[desc_current].flags & VIRTQ_DESC_F_NEXT)
382 t->virtio_ring_flags |= 1 << VIRTIO_TRACE_F_SIMPLE_CHAINED;
384 if (!(rxvq->packed_desc[desc_current].flags & VIRTQ_DESC_F_NEXT) &&
385 !(rxvq->packed_desc[desc_current].flags & VIRTQ_DESC_F_INDIRECT))
387 t->virtio_ring_flags |= 1 << VIRTIO_TRACE_F_SINGLE_DESC;
390 t->first_desc_len = hdr_desc ? hdr_desc->len : 0;
393 static_always_inline uword
394 vhost_user_device_class_packed (vlib_main_t * vm, vlib_node_runtime_t * node,
395 vlib_frame_t * frame)
397 u32 *buffers = vlib_frame_vector_args (frame);
398 u32 n_left = frame->n_vectors;
399 vhost_user_main_t *vum = &vhost_user_main;
400 vnet_interface_output_runtime_t *rd = (void *) node->runtime_data;
401 vhost_user_intf_t *vui =
402 pool_elt_at_index (vum->vhost_user_interfaces, rd->dev_instance);
404 vhost_user_vring_t *rxvq;
406 u32 thread_index = vm->thread_index;
407 vhost_cpu_t *cpu = &vum->cpus[thread_index];
412 vring_packed_desc_t *desc_table;
414 u16 desc_head, desc_index, desc_len;
415 u16 n_descs_processed;
416 u8 indirect, chained;
418 qid = VHOST_VRING_IDX_RX (*vec_elt_at_index (vui->per_cpu_tx_qid,
420 rxvq = &vui->vrings[qid];
423 error = VHOST_USER_TX_FUNC_ERROR_NONE;
426 n_descs_processed = 0;
430 vlib_buffer_t *b0, *current_b0;
431 uword buffer_map_addr;
434 u32 total_desc_len = 0;
439 if (PREDICT_TRUE (n_left > 1))
440 vlib_prefetch_buffer_with_index (vm, buffers[1], LOAD);
442 b0 = vlib_get_buffer (vm, buffers[0]);
443 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
445 cpu->current_trace = vlib_add_trace (vm, node, b0,
446 sizeof (*cpu->current_trace));
447 vhost_user_tx_trace_packed (cpu->current_trace, vui, qid / 2, b0,
451 desc_table = rxvq->packed_desc;
452 desc_head = desc_index = rxvq->last_avail_idx & rxvq->qsz_mask;
453 if (PREDICT_FALSE (!vhost_user_packed_desc_available (rxvq, desc_head)))
455 error = VHOST_USER_TX_FUNC_ERROR_PKT_DROP_NOBUF;
459 * Go deeper in case of indirect descriptor.
460 * To test it, turn off mrg_rxbuf.
462 if (desc_table[desc_head].flags & VIRTQ_DESC_F_INDIRECT)
465 if (PREDICT_FALSE (desc_table[desc_head].len <
466 sizeof (vring_packed_desc_t)))
468 error = VHOST_USER_TX_FUNC_ERROR_INDIRECT_OVERFLOW;
471 n_entries = desc_table[desc_head].len >> 4;
472 desc_table = map_guest_mem (vui, desc_table[desc_index].addr,
474 if (PREDICT_FALSE (desc_table == 0))
476 error = VHOST_USER_TX_FUNC_ERROR_MMAP_FAIL;
481 else if (rxvq->packed_desc[desc_head].flags & VIRTQ_DESC_F_NEXT)
484 desc_len = vui->virtio_net_hdr_sz;
485 buffer_map_addr = desc_table[desc_index].addr;
486 buffer_len = desc_table[desc_index].len;
488 /* Get a header from the header array */
489 virtio_net_hdr_mrg_rxbuf_t *hdr = &cpu->tx_headers[tx_headers_len];
492 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE;
493 hdr->num_buffers = 1;
495 or_flags = (b0->flags & VNET_BUFFER_F_OFFLOAD_IP_CKSUM) ||
496 (b0->flags & VNET_BUFFER_F_OFFLOAD_UDP_CKSUM) ||
497 (b0->flags & VNET_BUFFER_F_OFFLOAD_TCP_CKSUM);
499 /* Guest supports csum offload and buffer requires checksum offload? */
501 (vui->features & (1ULL << FEAT_VIRTIO_NET_F_GUEST_CSUM)))
502 vhost_user_handle_tx_offload (vui, b0, &hdr->hdr);
504 /* Prepare a copy order executed later for the header */
505 ASSERT (copy_len < VHOST_USER_COPY_ARRAY_N);
506 vhost_copy_t *cpy = &cpu->copy[copy_len];
508 cpy->len = vui->virtio_net_hdr_sz;
509 cpy->dst = buffer_map_addr;
510 cpy->src = (uword) hdr;
512 buffer_map_addr += vui->virtio_net_hdr_sz;
513 buffer_len -= vui->virtio_net_hdr_sz;
514 bytes_left = b0->current_length;
524 * Next one is chained
525 * Test it with both indirect and mrg_rxbuf off
527 if (PREDICT_FALSE (!(desc_table[desc_index].flags &
531 * Last descriptor in chain.
532 * Dequeue queued descriptors for this packet
534 vhost_user_dequeue_chained_descs (rxvq,
536 error = VHOST_USER_TX_FUNC_ERROR_PKT_DROP_NOBUF;
539 vhost_user_advance_last_avail_idx (rxvq);
540 desc_index = rxvq->last_avail_idx & rxvq->qsz_mask;
542 buffer_map_addr = desc_table[desc_index].addr;
543 buffer_len = desc_table[desc_index].len;
544 total_desc_len += desc_len;
551 * Test it with mrg_rxnuf off
553 if (PREDICT_TRUE (n_entries > 0))
557 /* Dequeue queued descriptors for this packet */
558 vhost_user_dequeue_chained_descs (rxvq,
560 error = VHOST_USER_TX_FUNC_ERROR_INDIRECT_OVERFLOW;
563 total_desc_len += desc_len;
564 desc_index = (desc_index + 1) & rxvq->qsz_mask;
565 buffer_map_addr = desc_table[desc_index].addr;
566 buffer_len = desc_table[desc_index].len;
569 else if (vui->virtio_net_hdr_sz == 12)
573 * This is the default setting for the guest VM
575 virtio_net_hdr_mrg_rxbuf_t *hdr =
576 &cpu->tx_headers[tx_headers_len - 1];
578 desc_table[desc_index].len = desc_len;
579 vhost_user_advance_last_avail_idx (rxvq);
580 desc_head = desc_index =
581 rxvq->last_avail_idx & rxvq->qsz_mask;
586 if (PREDICT_FALSE (!vhost_user_packed_desc_available
589 /* Dequeue queued descriptors for this packet */
590 vhost_user_dequeue_descs (rxvq, hdr,
592 error = VHOST_USER_TX_FUNC_ERROR_PKT_DROP_NOBUF;
596 buffer_map_addr = desc_table[desc_index].addr;
597 buffer_len = desc_table[desc_index].len;
601 error = VHOST_USER_TX_FUNC_ERROR_PKT_DROP_NOMRG;
606 ASSERT (copy_len < VHOST_USER_COPY_ARRAY_N);
607 vhost_copy_t *cpy = &cpu->copy[copy_len];
609 cpy->len = bytes_left;
610 cpy->len = (cpy->len > buffer_len) ? buffer_len : cpy->len;
611 cpy->dst = buffer_map_addr;
612 cpy->src = (uword) vlib_buffer_get_current (current_b0) +
613 current_b0->current_length - bytes_left;
615 bytes_left -= cpy->len;
616 buffer_len -= cpy->len;
617 buffer_map_addr += cpy->len;
618 desc_len += cpy->len;
620 CLIB_PREFETCH (&rxvq->packed_desc, CLIB_CACHE_LINE_BYTES, LOAD);
622 /* Check if vlib buffer has more data. If not, get more or break */
623 if (PREDICT_TRUE (!bytes_left))
626 (current_b0->flags & VLIB_BUFFER_NEXT_PRESENT))
628 current_b0 = vlib_get_buffer (vm, current_b0->next_buffer);
629 bytes_left = current_b0->current_length;
639 /* Move from available to used ring */
640 total_desc_len += desc_len;
641 rxvq->packed_desc[desc_head].len = total_desc_len;
643 vhost_user_advance_last_avail_table_idx (vui, rxvq, chained);
646 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
647 cpu->current_trace->hdr = cpu->tx_headers[tx_headers_len - 1];
652 * Do the copy periodically to prevent
653 * cpu->copy array overflow and corrupt memory
655 if (PREDICT_FALSE (copy_len >= VHOST_USER_TX_COPY_THRESHOLD) || chained)
657 if (PREDICT_FALSE (vhost_user_tx_copy (vui, cpu->copy, copy_len,
659 vlib_error_count (vm, node->node_index,
660 VHOST_USER_TX_FUNC_ERROR_MMAP_FAIL, 1);
663 /* give buffers back to driver */
664 vhost_user_mark_desc_available (vm, rxvq, &n_descs_processed,
665 chained, frame, n_left);
672 if (PREDICT_TRUE (copy_len))
674 if (PREDICT_FALSE (vhost_user_tx_copy (vui, cpu->copy, copy_len,
676 vlib_error_count (vm, node->node_index,
677 VHOST_USER_TX_FUNC_ERROR_MMAP_FAIL, 1);
679 vhost_user_mark_desc_available (vm, rxvq, &n_descs_processed, chained,
684 * When n_left is set, error is always set to something too.
685 * In case error is due to lack of remaining buffers, we go back up and
687 * The idea is that it is better to waste some time on packets
688 * that have been processed already than dropping them and get
689 * more fresh packets with a good likelyhood that they will be dropped too.
690 * This technique also gives more time to VM driver to pick-up packets.
691 * In case the traffic flows from physical to virtual interfaces, this
692 * technique will end-up leveraging the physical NIC buffer in order to
693 * absorb the VM's CPU jitter.
695 if (n_left && (error == VHOST_USER_TX_FUNC_ERROR_PKT_DROP_NOBUF) && retry)
701 vhost_user_vring_unlock (vui, qid);
703 if (PREDICT_FALSE (n_left && error != VHOST_USER_TX_FUNC_ERROR_NONE))
705 vlib_error_count (vm, node->node_index, error, n_left);
706 vlib_increment_simple_counter
707 (vnet_main.interface_main.sw_if_counters +
708 VNET_INTERFACE_COUNTER_DROP, thread_index, vui->sw_if_index, n_left);
711 vlib_buffer_free (vm, vlib_frame_vector_args (frame), frame->n_vectors);
712 return frame->n_vectors;
715 VNET_DEVICE_CLASS_TX_FN (vhost_user_device_class) (vlib_main_t * vm,
716 vlib_node_runtime_t *
717 node, vlib_frame_t * frame)
719 u32 *buffers = vlib_frame_vector_args (frame);
720 u32 n_left = frame->n_vectors;
721 vhost_user_main_t *vum = &vhost_user_main;
722 vnet_interface_output_runtime_t *rd = (void *) node->runtime_data;
723 vhost_user_intf_t *vui =
724 pool_elt_at_index (vum->vhost_user_interfaces, rd->dev_instance);
726 vhost_user_vring_t *rxvq;
728 u32 thread_index = vm->thread_index;
729 vhost_cpu_t *cpu = &vum->cpus[thread_index];
736 if (PREDICT_FALSE (!vui->admin_up))
738 error = VHOST_USER_TX_FUNC_ERROR_DOWN;
742 if (PREDICT_FALSE (!vui->is_ready))
744 error = VHOST_USER_TX_FUNC_ERROR_NOT_READY;
748 qid = VHOST_VRING_IDX_RX (*vec_elt_at_index (vui->per_cpu_tx_qid,
750 rxvq = &vui->vrings[qid];
751 if (PREDICT_FALSE (rxvq->avail == 0))
753 error = VHOST_USER_TX_FUNC_ERROR_MMAP_FAIL;
757 if (PREDICT_FALSE (vui->use_tx_spinlock))
758 vhost_user_vring_lock (vui, qid);
760 if (vhost_user_is_packed_ring_supported (vui))
761 return (vhost_user_device_class_packed (vm, node, frame));
764 error = VHOST_USER_TX_FUNC_ERROR_NONE;
769 vlib_buffer_t *b0, *current_b0;
770 u16 desc_head, desc_index, desc_len;
771 vring_desc_t *desc_table;
772 uword buffer_map_addr;
776 if (PREDICT_TRUE (n_left > 1))
777 vlib_prefetch_buffer_with_index (vm, buffers[1], LOAD);
779 b0 = vlib_get_buffer (vm, buffers[0]);
781 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
783 cpu->current_trace = vlib_add_trace (vm, node, b0,
784 sizeof (*cpu->current_trace));
785 vhost_user_tx_trace (cpu->current_trace, vui, qid / 2, b0, rxvq);
788 if (PREDICT_FALSE (rxvq->last_avail_idx == rxvq->avail->idx))
790 error = VHOST_USER_TX_FUNC_ERROR_PKT_DROP_NOBUF;
794 desc_table = rxvq->desc;
795 desc_head = desc_index =
796 rxvq->avail->ring[rxvq->last_avail_idx & rxvq->qsz_mask];
798 /* Go deeper in case of indirect descriptor
799 * I don't know of any driver providing indirect for RX. */
800 if (PREDICT_FALSE (rxvq->desc[desc_head].flags & VIRTQ_DESC_F_INDIRECT))
803 (rxvq->desc[desc_head].len < sizeof (vring_desc_t)))
805 error = VHOST_USER_TX_FUNC_ERROR_INDIRECT_OVERFLOW;
810 map_guest_mem (vui, rxvq->desc[desc_index].addr,
813 error = VHOST_USER_TX_FUNC_ERROR_MMAP_FAIL;
819 desc_len = vui->virtio_net_hdr_sz;
820 buffer_map_addr = desc_table[desc_index].addr;
821 buffer_len = desc_table[desc_index].len;
824 // Get a header from the header array
825 virtio_net_hdr_mrg_rxbuf_t *hdr = &cpu->tx_headers[tx_headers_len];
828 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE;
829 hdr->num_buffers = 1; //This is local, no need to check
831 or_flags = (b0->flags & VNET_BUFFER_F_OFFLOAD_IP_CKSUM) ||
832 (b0->flags & VNET_BUFFER_F_OFFLOAD_UDP_CKSUM) ||
833 (b0->flags & VNET_BUFFER_F_OFFLOAD_TCP_CKSUM);
835 /* Guest supports csum offload and buffer requires checksum offload? */
837 && (vui->features & (1ULL << FEAT_VIRTIO_NET_F_GUEST_CSUM)))
838 vhost_user_handle_tx_offload (vui, b0, &hdr->hdr);
840 // Prepare a copy order executed later for the header
841 ASSERT (copy_len < VHOST_USER_COPY_ARRAY_N);
842 vhost_copy_t *cpy = &cpu->copy[copy_len];
844 cpy->len = vui->virtio_net_hdr_sz;
845 cpy->dst = buffer_map_addr;
846 cpy->src = (uword) hdr;
849 buffer_map_addr += vui->virtio_net_hdr_sz;
850 buffer_len -= vui->virtio_net_hdr_sz;
851 bytes_left = b0->current_length;
857 if (desc_table[desc_index].flags & VIRTQ_DESC_F_NEXT)
859 //Next one is chained
860 desc_index = desc_table[desc_index].next;
861 buffer_map_addr = desc_table[desc_index].addr;
862 buffer_len = desc_table[desc_index].len;
864 else if (vui->virtio_net_hdr_sz == 12) //MRG is available
866 virtio_net_hdr_mrg_rxbuf_t *hdr =
867 &cpu->tx_headers[tx_headers_len - 1];
869 //Move from available to used buffer
870 rxvq->used->ring[rxvq->last_used_idx & rxvq->qsz_mask].id =
872 rxvq->used->ring[rxvq->last_used_idx & rxvq->qsz_mask].len =
874 vhost_user_log_dirty_ring (vui, rxvq,
875 ring[rxvq->last_used_idx &
878 rxvq->last_avail_idx++;
879 rxvq->last_used_idx++;
884 (rxvq->last_avail_idx == rxvq->avail->idx))
886 //Dequeue queued descriptors for this packet
887 rxvq->last_used_idx -= hdr->num_buffers - 1;
888 rxvq->last_avail_idx -= hdr->num_buffers - 1;
889 error = VHOST_USER_TX_FUNC_ERROR_PKT_DROP_NOBUF;
893 desc_table = rxvq->desc;
894 desc_head = desc_index =
895 rxvq->avail->ring[rxvq->last_avail_idx & rxvq->qsz_mask];
897 (rxvq->desc[desc_head].flags & VIRTQ_DESC_F_INDIRECT))
899 //It is seriously unlikely that a driver will put indirect descriptor
900 //after non-indirect descriptor.
902 (rxvq->desc[desc_head].len < sizeof (vring_desc_t)))
904 error = VHOST_USER_TX_FUNC_ERROR_INDIRECT_OVERFLOW;
910 rxvq->desc[desc_index].addr,
913 error = VHOST_USER_TX_FUNC_ERROR_MMAP_FAIL;
918 buffer_map_addr = desc_table[desc_index].addr;
919 buffer_len = desc_table[desc_index].len;
923 error = VHOST_USER_TX_FUNC_ERROR_PKT_DROP_NOMRG;
929 ASSERT (copy_len < VHOST_USER_COPY_ARRAY_N);
930 vhost_copy_t *cpy = &cpu->copy[copy_len];
932 cpy->len = bytes_left;
933 cpy->len = (cpy->len > buffer_len) ? buffer_len : cpy->len;
934 cpy->dst = buffer_map_addr;
935 cpy->src = (uword) vlib_buffer_get_current (current_b0) +
936 current_b0->current_length - bytes_left;
938 bytes_left -= cpy->len;
939 buffer_len -= cpy->len;
940 buffer_map_addr += cpy->len;
941 desc_len += cpy->len;
943 CLIB_PREFETCH (&rxvq->desc, CLIB_CACHE_LINE_BYTES, LOAD);
946 // Check if vlib buffer has more data. If not, get more or break.
947 if (PREDICT_TRUE (!bytes_left))
950 (current_b0->flags & VLIB_BUFFER_NEXT_PRESENT))
952 current_b0 = vlib_get_buffer (vm, current_b0->next_buffer);
953 bytes_left = current_b0->current_length;
963 //Move from available to used ring
964 rxvq->used->ring[rxvq->last_used_idx & rxvq->qsz_mask].id = desc_head;
965 rxvq->used->ring[rxvq->last_used_idx & rxvq->qsz_mask].len = desc_len;
966 vhost_user_log_dirty_ring (vui, rxvq,
967 ring[rxvq->last_used_idx & rxvq->qsz_mask]);
968 rxvq->last_avail_idx++;
969 rxvq->last_used_idx++;
971 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
973 cpu->current_trace->hdr = cpu->tx_headers[tx_headers_len - 1];
976 n_left--; //At the end for error counting when 'goto done' is invoked
979 * Do the copy periodically to prevent
980 * cpu->copy array overflow and corrupt memory
982 if (PREDICT_FALSE (copy_len >= VHOST_USER_TX_COPY_THRESHOLD))
984 if (PREDICT_FALSE (vhost_user_tx_copy (vui, cpu->copy, copy_len,
987 vlib_error_count (vm, node->node_index,
988 VHOST_USER_TX_FUNC_ERROR_MMAP_FAIL, 1);
992 /* give buffers back to driver */
993 CLIB_MEMORY_BARRIER ();
994 rxvq->used->idx = rxvq->last_used_idx;
995 vhost_user_log_dirty_ring (vui, rxvq, idx);
1001 //Do the memory copies
1002 if (PREDICT_FALSE (vhost_user_tx_copy (vui, cpu->copy, copy_len,
1005 vlib_error_count (vm, node->node_index,
1006 VHOST_USER_TX_FUNC_ERROR_MMAP_FAIL, 1);
1009 CLIB_MEMORY_BARRIER ();
1010 rxvq->used->idx = rxvq->last_used_idx;
1011 vhost_user_log_dirty_ring (vui, rxvq, idx);
1014 * When n_left is set, error is always set to something too.
1015 * In case error is due to lack of remaining buffers, we go back up and
1017 * The idea is that it is better to waste some time on packets
1018 * that have been processed already than dropping them and get
1019 * more fresh packets with a good likelihood that they will be dropped too.
1020 * This technique also gives more time to VM driver to pick-up packets.
1021 * In case the traffic flows from physical to virtual interfaces, this
1022 * technique will end-up leveraging the physical NIC buffer in order to
1023 * absorb the VM's CPU jitter.
1025 if (n_left && (error == VHOST_USER_TX_FUNC_ERROR_PKT_DROP_NOBUF) && retry)
1031 /* interrupt (call) handling */
1032 if ((rxvq->callfd_idx != ~0) &&
1033 !(rxvq->avail->flags & VRING_AVAIL_F_NO_INTERRUPT))
1035 rxvq->n_since_last_int += frame->n_vectors - n_left;
1037 if (rxvq->n_since_last_int > vum->coalesce_frames)
1038 vhost_user_send_call (vm, rxvq);
1041 vhost_user_vring_unlock (vui, qid);
1044 if (PREDICT_FALSE (n_left && error != VHOST_USER_TX_FUNC_ERROR_NONE))
1046 vlib_error_count (vm, node->node_index, error, n_left);
1047 vlib_increment_simple_counter
1048 (vnet_main.interface_main.sw_if_counters
1049 + VNET_INTERFACE_COUNTER_DROP,
1050 thread_index, vui->sw_if_index, n_left);
1053 vlib_buffer_free (vm, vlib_frame_vector_args (frame), frame->n_vectors);
1054 return frame->n_vectors;
1057 static __clib_unused clib_error_t *
1058 vhost_user_interface_rx_mode_change (vnet_main_t * vnm, u32 hw_if_index,
1059 u32 qid, vnet_hw_interface_rx_mode mode)
1061 vlib_main_t *vm = vnm->vlib_main;
1062 vnet_hw_interface_t *hif = vnet_get_hw_interface (vnm, hw_if_index);
1063 vhost_user_main_t *vum = &vhost_user_main;
1064 vhost_user_intf_t *vui =
1065 pool_elt_at_index (vum->vhost_user_interfaces, hif->dev_instance);
1066 vhost_user_vring_t *txvq = &vui->vrings[VHOST_VRING_IDX_TX (qid)];
1068 if ((mode == VNET_HW_INTERFACE_RX_MODE_INTERRUPT) ||
1069 (mode == VNET_HW_INTERFACE_RX_MODE_ADAPTIVE))
1071 if (txvq->kickfd_idx == ~0)
1073 // We cannot support interrupt mode if the driver opts out
1074 return clib_error_return (0, "Driver does not support interrupt");
1076 if (txvq->mode == VNET_HW_INTERFACE_RX_MODE_POLLING)
1079 // Start the timer if this is the first encounter on interrupt
1081 if ((vum->ifq_count == 1) &&
1082 (vum->coalesce_time > 0.0) && (vum->coalesce_frames > 0))
1083 vlib_process_signal_event (vm,
1084 vhost_user_send_interrupt_node.index,
1085 VHOST_USER_EVENT_START_TIMER, 0);
1088 else if (mode == VNET_HW_INTERFACE_RX_MODE_POLLING)
1090 if (((txvq->mode == VNET_HW_INTERFACE_RX_MODE_INTERRUPT) ||
1091 (txvq->mode == VNET_HW_INTERFACE_RX_MODE_ADAPTIVE)) &&
1095 // Stop the timer if there is no more interrupt interface/queue
1096 if ((vum->ifq_count == 0) &&
1097 (vum->coalesce_time > 0.0) && (vum->coalesce_frames > 0))
1098 vlib_process_signal_event (vm,
1099 vhost_user_send_interrupt_node.index,
1100 VHOST_USER_EVENT_STOP_TIMER, 0);
1105 if (mode == VNET_HW_INTERFACE_RX_MODE_POLLING)
1106 txvq->used->flags = VRING_USED_F_NO_NOTIFY;
1107 else if ((mode == VNET_HW_INTERFACE_RX_MODE_ADAPTIVE) ||
1108 (mode == VNET_HW_INTERFACE_RX_MODE_INTERRUPT))
1109 txvq->used->flags = 0;
1112 vu_log_err (vui, "unhandled mode %d changed for if %d queue %d", mode,
1114 return clib_error_return (0, "unsupported");
1120 static __clib_unused clib_error_t *
1121 vhost_user_interface_admin_up_down (vnet_main_t * vnm, u32 hw_if_index,
1124 vnet_hw_interface_t *hif = vnet_get_hw_interface (vnm, hw_if_index);
1125 vhost_user_main_t *vum = &vhost_user_main;
1126 vhost_user_intf_t *vui =
1127 pool_elt_at_index (vum->vhost_user_interfaces, hif->dev_instance);
1128 u8 link_old, link_new;
1130 link_old = vui_is_link_up (vui);
1132 vui->admin_up = (flags & VNET_SW_INTERFACE_FLAG_ADMIN_UP) != 0;
1134 link_new = vui_is_link_up (vui);
1136 if (link_old != link_new)
1137 vnet_hw_interface_set_flags (vnm, vui->hw_if_index, link_new ?
1138 VNET_HW_INTERFACE_FLAG_LINK_UP : 0);
1140 return /* no error */ 0;
1144 VNET_DEVICE_CLASS (vhost_user_device_class) = {
1145 .name = "vhost-user",
1146 .tx_function_n_errors = VHOST_USER_TX_FUNC_N_ERROR,
1147 .tx_function_error_strings = vhost_user_tx_func_error_strings,
1148 .format_device_name = format_vhost_user_interface_name,
1149 .name_renumber = vhost_user_name_renumber,
1150 .admin_up_down_function = vhost_user_interface_admin_up_down,
1151 .rx_mode_change_function = vhost_user_interface_rx_mode_change,
1152 .format_tx_trace = format_vhost_trace,
1158 * fd.io coding-style-patch-verification: ON
1161 * eval: (c-set-style "gnu")