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/ethernet/ethernet.h>
38 #include <vnet/devices/devices.h>
39 #include <vnet/feature/feature.h>
41 #include <vnet/devices/virtio/vhost_user.h>
42 #include <vnet/devices/virtio/vhost_user_inline.h>
44 #include <vnet/gso/hdr_offset_parser.h>
46 * On the transmit side, we keep processing the buffers from vlib in the while
47 * loop and prepare the copy order to be executed later. However, the static
48 * array which we keep the copy order is limited to VHOST_USER_COPY_ARRAY_N
49 * entries. In order to not corrupt memory, we have to do the copy when the
50 * static array reaches the copy threshold. We subtract 40 in case the code
51 * goes into the inner loop for a maximum of 64k frames which may require
52 * more array entries. We subtract 200 because our default buffer size is
53 * 2048 and the default desc len is likely 1536. While it takes less than 40
54 * vlib buffers for the jumbo frame, it may take twice as much descriptors
55 * for the same jumbo frame. Use 200 for the extra head room.
57 #define VHOST_USER_TX_COPY_THRESHOLD (VHOST_USER_COPY_ARRAY_N - 200)
59 extern vnet_device_class_t vhost_user_device_class;
61 #define foreach_vhost_user_tx_func_error \
63 _(NOT_READY, "vhost vring not ready") \
64 _(DOWN, "vhost interface is down") \
65 _(PKT_DROP_NOBUF, "tx packet drops (no available descriptors)") \
66 _(PKT_DROP_NOMRG, "tx packet drops (cannot merge descriptors)") \
67 _(MMAP_FAIL, "mmap failure") \
68 _(INDIRECT_OVERFLOW, "indirect descriptor table overflow")
72 #define _(f,s) VHOST_USER_TX_FUNC_ERROR_##f,
73 foreach_vhost_user_tx_func_error
75 VHOST_USER_TX_FUNC_N_ERROR,
76 } vhost_user_tx_func_error_t;
78 static __clib_unused char *vhost_user_tx_func_error_strings[] = {
80 foreach_vhost_user_tx_func_error
84 static __clib_unused u8 *
85 format_vhost_user_interface_name (u8 * s, va_list * args)
87 u32 i = va_arg (*args, u32);
88 u32 show_dev_instance = ~0;
89 vhost_user_main_t *vum = &vhost_user_main;
91 if (i < vec_len (vum->show_dev_instance_by_real_dev_instance))
92 show_dev_instance = vum->show_dev_instance_by_real_dev_instance[i];
94 if (show_dev_instance != ~0)
95 i = show_dev_instance;
97 s = format (s, "VirtualEthernet0/0/%d", i);
101 static __clib_unused int
102 vhost_user_name_renumber (vnet_hw_interface_t * hi, u32 new_dev_instance)
104 // FIXME: check if the new dev instance is already used
105 vhost_user_main_t *vum = &vhost_user_main;
106 vhost_user_intf_t *vui = pool_elt_at_index (vum->vhost_user_interfaces,
109 vec_validate_init_empty (vum->show_dev_instance_by_real_dev_instance,
110 hi->dev_instance, ~0);
112 vum->show_dev_instance_by_real_dev_instance[hi->dev_instance] =
115 vu_log_debug (vui, "renumbered vhost-user interface dev_instance %d to %d",
116 hi->dev_instance, new_dev_instance);
122 * @brief Try once to lock the vring
123 * @return 0 on success, non-zero on failure.
125 static_always_inline int
126 vhost_user_vring_try_lock (vhost_user_intf_t * vui, u32 qid)
128 return clib_atomic_test_and_set (vui->vring_locks[qid]);
132 * @brief Spin until the vring is successfully locked
134 static_always_inline void
135 vhost_user_vring_lock (vhost_user_intf_t * vui, u32 qid)
137 while (vhost_user_vring_try_lock (vui, qid))
142 * @brief Unlock the vring lock
144 static_always_inline void
145 vhost_user_vring_unlock (vhost_user_intf_t * vui, u32 qid)
147 clib_atomic_release (vui->vring_locks[qid]);
150 static_always_inline void
151 vhost_user_tx_trace (vhost_trace_t * t,
152 vhost_user_intf_t * vui, u16 qid,
153 vlib_buffer_t * b, vhost_user_vring_t * rxvq)
155 vhost_user_main_t *vum = &vhost_user_main;
156 u32 last_avail_idx = rxvq->last_avail_idx;
157 u32 desc_current = rxvq->avail->ring[last_avail_idx & rxvq->qsz_mask];
158 vring_desc_t *hdr_desc = 0;
161 clib_memset (t, 0, sizeof (*t));
162 t->device_index = vui - vum->vhost_user_interfaces;
165 hdr_desc = &rxvq->desc[desc_current];
166 if (rxvq->desc[desc_current].flags & VRING_DESC_F_INDIRECT)
168 t->virtio_ring_flags |= 1 << VIRTIO_TRACE_F_INDIRECT;
169 /* Header is the first here */
170 hdr_desc = map_guest_mem (vui, rxvq->desc[desc_current].addr, &hint);
172 if (rxvq->desc[desc_current].flags & VRING_DESC_F_NEXT)
174 t->virtio_ring_flags |= 1 << VIRTIO_TRACE_F_SIMPLE_CHAINED;
176 if (!(rxvq->desc[desc_current].flags & VRING_DESC_F_NEXT) &&
177 !(rxvq->desc[desc_current].flags & VRING_DESC_F_INDIRECT))
179 t->virtio_ring_flags |= 1 << VIRTIO_TRACE_F_SINGLE_DESC;
182 t->first_desc_len = hdr_desc ? hdr_desc->len : 0;
185 static_always_inline u32
186 vhost_user_tx_copy (vhost_user_intf_t * vui, vhost_copy_t * cpy,
187 u16 copy_len, u32 * map_hint)
189 void *dst0, *dst1, *dst2, *dst3;
190 if (PREDICT_TRUE (copy_len >= 4))
192 if (PREDICT_FALSE (!(dst2 = map_guest_mem (vui, cpy[0].dst, map_hint))))
194 if (PREDICT_FALSE (!(dst3 = map_guest_mem (vui, cpy[1].dst, map_hint))))
196 while (PREDICT_TRUE (copy_len >= 4))
202 (!(dst2 = map_guest_mem (vui, cpy[2].dst, map_hint))))
205 (!(dst3 = map_guest_mem (vui, cpy[3].dst, map_hint))))
208 CLIB_PREFETCH ((void *) cpy[2].src, 64, LOAD);
209 CLIB_PREFETCH ((void *) cpy[3].src, 64, LOAD);
211 clib_memcpy_fast (dst0, (void *) cpy[0].src, cpy[0].len);
212 clib_memcpy_fast (dst1, (void *) cpy[1].src, cpy[1].len);
214 vhost_user_log_dirty_pages_2 (vui, cpy[0].dst, cpy[0].len, 1);
215 vhost_user_log_dirty_pages_2 (vui, cpy[1].dst, cpy[1].len, 1);
222 if (PREDICT_FALSE (!(dst0 = map_guest_mem (vui, cpy->dst, map_hint))))
224 clib_memcpy_fast (dst0, (void *) cpy->src, cpy->len);
225 vhost_user_log_dirty_pages_2 (vui, cpy->dst, cpy->len, 1);
232 static_always_inline void
233 vhost_user_handle_tx_offload (vhost_user_intf_t * vui, vlib_buffer_t * b,
234 virtio_net_hdr_t * hdr)
236 generic_header_offset_t gho = { 0 };
237 int is_ip4 = b->flags & VNET_BUFFER_F_IS_IP4;
238 int is_ip6 = b->flags & VNET_BUFFER_F_IS_IP6;
240 ASSERT (!(is_ip4 && is_ip6));
241 vnet_generic_header_offset_parser (b, &gho, 1 /* l2 */ , is_ip4, is_ip6);
242 if (b->flags & VNET_BUFFER_F_OFFLOAD_IP_CKSUM)
247 (ip4_header_t *) (vlib_buffer_get_current (b) + gho.l3_hdr_offset);
248 ip4->checksum = ip4_header_checksum (ip4);
251 /* checksum offload */
252 if (b->flags & VNET_BUFFER_F_OFFLOAD_UDP_CKSUM)
254 hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
255 hdr->csum_start = gho.l4_hdr_offset;
256 hdr->csum_offset = offsetof (udp_header_t, checksum);
258 else if (b->flags & VNET_BUFFER_F_OFFLOAD_TCP_CKSUM)
260 hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
261 hdr->csum_start = gho.l4_hdr_offset;
262 hdr->csum_offset = offsetof (tcp_header_t, checksum);
266 if (b->flags & VNET_BUFFER_F_GSO)
268 if (b->flags & VNET_BUFFER_F_OFFLOAD_TCP_CKSUM)
271 (vui->features & VIRTIO_FEATURE (VIRTIO_NET_F_GUEST_TSO4)))
273 hdr->gso_size = vnet_buffer2 (b)->gso_size;
274 hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
277 (vui->features & VIRTIO_FEATURE (VIRTIO_NET_F_GUEST_TSO6)))
279 hdr->gso_size = vnet_buffer2 (b)->gso_size;
280 hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
283 else if ((vui->features & VIRTIO_FEATURE (VIRTIO_NET_F_GUEST_UFO)) &&
284 (b->flags & VNET_BUFFER_F_OFFLOAD_UDP_CKSUM))
286 hdr->gso_size = vnet_buffer2 (b)->gso_size;
287 hdr->gso_type = VIRTIO_NET_HDR_GSO_UDP;
292 static_always_inline void
293 vhost_user_mark_desc_available (vlib_main_t * vm, vhost_user_vring_t * rxvq,
294 u16 * n_descs_processed, u8 chained,
295 vlib_frame_t * frame, u32 n_left)
298 vring_packed_desc_t *desc_table = rxvq->packed_desc;
299 u16 last_used_idx = rxvq->last_used_idx;
301 if (PREDICT_FALSE (*n_descs_processed == 0))
304 if (rxvq->used_wrap_counter)
305 flags = desc_table[last_used_idx & rxvq->qsz_mask].flags |
306 (VRING_DESC_F_AVAIL | VRING_DESC_F_USED);
308 flags = desc_table[last_used_idx & rxvq->qsz_mask].flags &
309 ~(VRING_DESC_F_AVAIL | VRING_DESC_F_USED);
311 vhost_user_advance_last_used_idx (rxvq);
313 for (desc_idx = 1; desc_idx < *n_descs_processed; desc_idx++)
315 if (rxvq->used_wrap_counter)
316 desc_table[rxvq->last_used_idx & rxvq->qsz_mask].flags |=
317 (VRING_DESC_F_AVAIL | VRING_DESC_F_USED);
319 desc_table[rxvq->last_used_idx & rxvq->qsz_mask].flags &=
320 ~(VRING_DESC_F_AVAIL | VRING_DESC_F_USED);
321 vhost_user_advance_last_used_idx (rxvq);
324 desc_table[last_used_idx & rxvq->qsz_mask].flags = flags;
326 *n_descs_processed = 0;
330 vring_packed_desc_t *desc_table = rxvq->packed_desc;
332 while (desc_table[rxvq->last_used_idx & rxvq->qsz_mask].flags &
334 vhost_user_advance_last_used_idx (rxvq);
336 /* Advance past the current chained table entries */
337 vhost_user_advance_last_used_idx (rxvq);
340 /* interrupt (call) handling */
341 if ((rxvq->callfd_idx != ~0) &&
342 (rxvq->avail_event->flags != VRING_EVENT_F_DISABLE))
344 vhost_user_main_t *vum = &vhost_user_main;
346 rxvq->n_since_last_int += frame->n_vectors - n_left;
347 if (rxvq->n_since_last_int > vum->coalesce_frames)
348 vhost_user_send_call (vm, rxvq);
352 static_always_inline void
353 vhost_user_tx_trace_packed (vhost_trace_t * t, vhost_user_intf_t * vui,
354 u16 qid, vlib_buffer_t * b,
355 vhost_user_vring_t * rxvq)
357 vhost_user_main_t *vum = &vhost_user_main;
358 u32 last_avail_idx = rxvq->last_avail_idx;
359 u32 desc_current = last_avail_idx & rxvq->qsz_mask;
360 vring_packed_desc_t *hdr_desc = 0;
363 clib_memset (t, 0, sizeof (*t));
364 t->device_index = vui - vum->vhost_user_interfaces;
367 hdr_desc = &rxvq->packed_desc[desc_current];
368 if (rxvq->packed_desc[desc_current].flags & VRING_DESC_F_INDIRECT)
370 t->virtio_ring_flags |= 1 << VIRTIO_TRACE_F_INDIRECT;
371 /* Header is the first here */
372 hdr_desc = map_guest_mem (vui, rxvq->packed_desc[desc_current].addr,
375 if (rxvq->packed_desc[desc_current].flags & VRING_DESC_F_NEXT)
377 t->virtio_ring_flags |= 1 << VIRTIO_TRACE_F_SIMPLE_CHAINED;
379 if (!(rxvq->packed_desc[desc_current].flags & VRING_DESC_F_NEXT) &&
380 !(rxvq->packed_desc[desc_current].flags & VRING_DESC_F_INDIRECT))
382 t->virtio_ring_flags |= 1 << VIRTIO_TRACE_F_SINGLE_DESC;
385 t->first_desc_len = hdr_desc ? hdr_desc->len : 0;
388 static_always_inline uword
389 vhost_user_device_class_packed (vlib_main_t * vm, vlib_node_runtime_t * node,
390 vlib_frame_t * frame)
392 u32 *buffers = vlib_frame_vector_args (frame);
393 u32 n_left = frame->n_vectors;
394 vhost_user_main_t *vum = &vhost_user_main;
395 vnet_interface_output_runtime_t *rd = (void *) node->runtime_data;
396 vhost_user_intf_t *vui =
397 pool_elt_at_index (vum->vhost_user_interfaces, rd->dev_instance);
399 vhost_user_vring_t *rxvq;
401 u32 thread_index = vm->thread_index;
402 vhost_cpu_t *cpu = &vum->cpus[thread_index];
407 vring_packed_desc_t *desc_table;
409 u16 desc_head, desc_index, desc_len;
410 u16 n_descs_processed;
411 u8 indirect, chained;
413 qid = VHOST_VRING_IDX_RX (*vec_elt_at_index (vui->per_cpu_tx_qid,
415 rxvq = &vui->vrings[qid];
418 error = VHOST_USER_TX_FUNC_ERROR_NONE;
421 n_descs_processed = 0;
425 vlib_buffer_t *b0, *current_b0;
426 uword buffer_map_addr;
429 u32 total_desc_len = 0;
434 if (PREDICT_TRUE (n_left > 1))
435 vlib_prefetch_buffer_with_index (vm, buffers[1], LOAD);
437 b0 = vlib_get_buffer (vm, buffers[0]);
438 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
440 cpu->current_trace = vlib_add_trace (vm, node, b0,
441 sizeof (*cpu->current_trace));
442 vhost_user_tx_trace_packed (cpu->current_trace, vui, qid / 2, b0,
446 desc_table = rxvq->packed_desc;
447 desc_head = desc_index = rxvq->last_avail_idx & rxvq->qsz_mask;
448 if (PREDICT_FALSE (!vhost_user_packed_desc_available (rxvq, desc_head)))
450 error = VHOST_USER_TX_FUNC_ERROR_PKT_DROP_NOBUF;
454 * Go deeper in case of indirect descriptor.
455 * To test it, turn off mrg_rxbuf.
457 if (desc_table[desc_head].flags & VRING_DESC_F_INDIRECT)
460 if (PREDICT_FALSE (desc_table[desc_head].len <
461 sizeof (vring_packed_desc_t)))
463 error = VHOST_USER_TX_FUNC_ERROR_INDIRECT_OVERFLOW;
466 n_entries = desc_table[desc_head].len >> 4;
467 desc_table = map_guest_mem (vui, desc_table[desc_index].addr,
469 if (PREDICT_FALSE (desc_table == 0))
471 error = VHOST_USER_TX_FUNC_ERROR_MMAP_FAIL;
476 else if (rxvq->packed_desc[desc_head].flags & VRING_DESC_F_NEXT)
479 desc_len = vui->virtio_net_hdr_sz;
480 buffer_map_addr = desc_table[desc_index].addr;
481 buffer_len = desc_table[desc_index].len;
483 /* Get a header from the header array */
484 virtio_net_hdr_mrg_rxbuf_t *hdr = &cpu->tx_headers[tx_headers_len];
487 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE;
488 hdr->num_buffers = 1;
490 or_flags = (b0->flags & VNET_BUFFER_F_OFFLOAD_IP_CKSUM) ||
491 (b0->flags & VNET_BUFFER_F_OFFLOAD_UDP_CKSUM) ||
492 (b0->flags & VNET_BUFFER_F_OFFLOAD_TCP_CKSUM);
494 /* Guest supports csum offload and buffer requires checksum offload? */
496 (vui->features & VIRTIO_FEATURE (VIRTIO_NET_F_GUEST_CSUM)))
497 vhost_user_handle_tx_offload (vui, b0, &hdr->hdr);
499 /* Prepare a copy order executed later for the header */
500 ASSERT (copy_len < VHOST_USER_COPY_ARRAY_N);
501 vhost_copy_t *cpy = &cpu->copy[copy_len];
503 cpy->len = vui->virtio_net_hdr_sz;
504 cpy->dst = buffer_map_addr;
505 cpy->src = (uword) hdr;
507 buffer_map_addr += vui->virtio_net_hdr_sz;
508 buffer_len -= vui->virtio_net_hdr_sz;
509 bytes_left = b0->current_length;
519 * Next one is chained
520 * Test it with both indirect and mrg_rxbuf off
522 if (PREDICT_FALSE (!(desc_table[desc_index].flags &
526 * Last descriptor in chain.
527 * Dequeue queued descriptors for this packet
529 vhost_user_dequeue_chained_descs (rxvq,
531 error = VHOST_USER_TX_FUNC_ERROR_PKT_DROP_NOBUF;
534 vhost_user_advance_last_avail_idx (rxvq);
535 desc_index = rxvq->last_avail_idx & rxvq->qsz_mask;
537 buffer_map_addr = desc_table[desc_index].addr;
538 buffer_len = desc_table[desc_index].len;
539 total_desc_len += desc_len;
546 * Test it with mrg_rxnuf off
548 if (PREDICT_TRUE (n_entries > 0))
552 /* Dequeue queued descriptors for this packet */
553 vhost_user_dequeue_chained_descs (rxvq,
555 error = VHOST_USER_TX_FUNC_ERROR_INDIRECT_OVERFLOW;
558 total_desc_len += desc_len;
559 desc_index = (desc_index + 1) & rxvq->qsz_mask;
560 buffer_map_addr = desc_table[desc_index].addr;
561 buffer_len = desc_table[desc_index].len;
564 else if (vui->virtio_net_hdr_sz == 12)
568 * This is the default setting for the guest VM
570 virtio_net_hdr_mrg_rxbuf_t *hdr =
571 &cpu->tx_headers[tx_headers_len - 1];
573 desc_table[desc_index].len = desc_len;
574 vhost_user_advance_last_avail_idx (rxvq);
575 desc_head = desc_index =
576 rxvq->last_avail_idx & rxvq->qsz_mask;
581 if (PREDICT_FALSE (!vhost_user_packed_desc_available
584 /* Dequeue queued descriptors for this packet */
585 vhost_user_dequeue_descs (rxvq, hdr,
587 error = VHOST_USER_TX_FUNC_ERROR_PKT_DROP_NOBUF;
591 buffer_map_addr = desc_table[desc_index].addr;
592 buffer_len = desc_table[desc_index].len;
596 error = VHOST_USER_TX_FUNC_ERROR_PKT_DROP_NOMRG;
601 ASSERT (copy_len < VHOST_USER_COPY_ARRAY_N);
602 vhost_copy_t *cpy = &cpu->copy[copy_len];
604 cpy->len = bytes_left;
605 cpy->len = (cpy->len > buffer_len) ? buffer_len : cpy->len;
606 cpy->dst = buffer_map_addr;
607 cpy->src = (uword) vlib_buffer_get_current (current_b0) +
608 current_b0->current_length - bytes_left;
610 bytes_left -= cpy->len;
611 buffer_len -= cpy->len;
612 buffer_map_addr += cpy->len;
613 desc_len += cpy->len;
615 CLIB_PREFETCH (&rxvq->packed_desc, CLIB_CACHE_LINE_BYTES, LOAD);
617 /* Check if vlib buffer has more data. If not, get more or break */
618 if (PREDICT_TRUE (!bytes_left))
621 (current_b0->flags & VLIB_BUFFER_NEXT_PRESENT))
623 current_b0 = vlib_get_buffer (vm, current_b0->next_buffer);
624 bytes_left = current_b0->current_length;
634 /* Move from available to used ring */
635 total_desc_len += desc_len;
636 rxvq->packed_desc[desc_head].len = total_desc_len;
638 vhost_user_advance_last_avail_table_idx (vui, rxvq, chained);
641 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
642 cpu->current_trace->hdr = cpu->tx_headers[tx_headers_len - 1];
647 * Do the copy periodically to prevent
648 * cpu->copy array overflow and corrupt memory
650 if (PREDICT_FALSE (copy_len >= VHOST_USER_TX_COPY_THRESHOLD) || chained)
652 if (PREDICT_FALSE (vhost_user_tx_copy (vui, cpu->copy, copy_len,
654 vlib_error_count (vm, node->node_index,
655 VHOST_USER_TX_FUNC_ERROR_MMAP_FAIL, 1);
658 /* give buffers back to driver */
659 vhost_user_mark_desc_available (vm, rxvq, &n_descs_processed,
660 chained, frame, n_left);
667 if (PREDICT_TRUE (copy_len))
669 if (PREDICT_FALSE (vhost_user_tx_copy (vui, cpu->copy, copy_len,
671 vlib_error_count (vm, node->node_index,
672 VHOST_USER_TX_FUNC_ERROR_MMAP_FAIL, 1);
674 vhost_user_mark_desc_available (vm, rxvq, &n_descs_processed, chained,
679 * When n_left is set, error is always set to something too.
680 * In case error is due to lack of remaining buffers, we go back up and
682 * The idea is that it is better to waste some time on packets
683 * that have been processed already than dropping them and get
684 * more fresh packets with a good likelyhood that they will be dropped too.
685 * This technique also gives more time to VM driver to pick-up packets.
686 * In case the traffic flows from physical to virtual interfaces, this
687 * technique will end-up leveraging the physical NIC buffer in order to
688 * absorb the VM's CPU jitter.
690 if (n_left && (error == VHOST_USER_TX_FUNC_ERROR_PKT_DROP_NOBUF) && retry)
696 vhost_user_vring_unlock (vui, qid);
698 if (PREDICT_FALSE (n_left && error != VHOST_USER_TX_FUNC_ERROR_NONE))
700 vlib_error_count (vm, node->node_index, error, n_left);
701 vlib_increment_simple_counter
702 (vnet_main.interface_main.sw_if_counters +
703 VNET_INTERFACE_COUNTER_DROP, thread_index, vui->sw_if_index, n_left);
706 vlib_buffer_free (vm, vlib_frame_vector_args (frame), frame->n_vectors);
707 return frame->n_vectors;
710 VNET_DEVICE_CLASS_TX_FN (vhost_user_device_class) (vlib_main_t * vm,
711 vlib_node_runtime_t *
712 node, vlib_frame_t * frame)
714 u32 *buffers = vlib_frame_vector_args (frame);
715 u32 n_left = frame->n_vectors;
716 vhost_user_main_t *vum = &vhost_user_main;
717 vnet_interface_output_runtime_t *rd = (void *) node->runtime_data;
718 vhost_user_intf_t *vui =
719 pool_elt_at_index (vum->vhost_user_interfaces, rd->dev_instance);
721 vhost_user_vring_t *rxvq;
723 u32 thread_index = vm->thread_index;
724 vhost_cpu_t *cpu = &vum->cpus[thread_index];
731 if (PREDICT_FALSE (!vui->admin_up))
733 error = VHOST_USER_TX_FUNC_ERROR_DOWN;
737 if (PREDICT_FALSE (!vui->is_ready))
739 error = VHOST_USER_TX_FUNC_ERROR_NOT_READY;
743 qid = VHOST_VRING_IDX_RX (*vec_elt_at_index (vui->per_cpu_tx_qid,
745 rxvq = &vui->vrings[qid];
746 if (PREDICT_FALSE (rxvq->avail == 0))
748 error = VHOST_USER_TX_FUNC_ERROR_MMAP_FAIL;
752 if (PREDICT_FALSE (vui->use_tx_spinlock))
753 vhost_user_vring_lock (vui, qid);
755 if (vhost_user_is_packed_ring_supported (vui))
756 return (vhost_user_device_class_packed (vm, node, frame));
759 error = VHOST_USER_TX_FUNC_ERROR_NONE;
764 vlib_buffer_t *b0, *current_b0;
765 u16 desc_head, desc_index, desc_len;
766 vring_desc_t *desc_table;
767 uword buffer_map_addr;
771 if (PREDICT_TRUE (n_left > 1))
772 vlib_prefetch_buffer_with_index (vm, buffers[1], LOAD);
774 b0 = vlib_get_buffer (vm, buffers[0]);
776 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
778 cpu->current_trace = vlib_add_trace (vm, node, b0,
779 sizeof (*cpu->current_trace));
780 vhost_user_tx_trace (cpu->current_trace, vui, qid / 2, b0, rxvq);
783 if (PREDICT_FALSE (rxvq->last_avail_idx == rxvq->avail->idx))
785 error = VHOST_USER_TX_FUNC_ERROR_PKT_DROP_NOBUF;
789 desc_table = rxvq->desc;
790 desc_head = desc_index =
791 rxvq->avail->ring[rxvq->last_avail_idx & rxvq->qsz_mask];
793 /* Go deeper in case of indirect descriptor
794 * I don't know of any driver providing indirect for RX. */
795 if (PREDICT_FALSE (rxvq->desc[desc_head].flags & VRING_DESC_F_INDIRECT))
798 (rxvq->desc[desc_head].len < sizeof (vring_desc_t)))
800 error = VHOST_USER_TX_FUNC_ERROR_INDIRECT_OVERFLOW;
805 map_guest_mem (vui, rxvq->desc[desc_index].addr,
808 error = VHOST_USER_TX_FUNC_ERROR_MMAP_FAIL;
814 desc_len = vui->virtio_net_hdr_sz;
815 buffer_map_addr = desc_table[desc_index].addr;
816 buffer_len = desc_table[desc_index].len;
819 // Get a header from the header array
820 virtio_net_hdr_mrg_rxbuf_t *hdr = &cpu->tx_headers[tx_headers_len];
823 hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE;
824 hdr->num_buffers = 1; //This is local, no need to check
826 or_flags = (b0->flags & VNET_BUFFER_F_OFFLOAD_IP_CKSUM) ||
827 (b0->flags & VNET_BUFFER_F_OFFLOAD_UDP_CKSUM) ||
828 (b0->flags & VNET_BUFFER_F_OFFLOAD_TCP_CKSUM);
830 /* Guest supports csum offload and buffer requires checksum offload? */
832 && (vui->features & VIRTIO_FEATURE (VIRTIO_NET_F_GUEST_CSUM)))
833 vhost_user_handle_tx_offload (vui, b0, &hdr->hdr);
835 // Prepare a copy order executed later for the header
836 ASSERT (copy_len < VHOST_USER_COPY_ARRAY_N);
837 vhost_copy_t *cpy = &cpu->copy[copy_len];
839 cpy->len = vui->virtio_net_hdr_sz;
840 cpy->dst = buffer_map_addr;
841 cpy->src = (uword) hdr;
844 buffer_map_addr += vui->virtio_net_hdr_sz;
845 buffer_len -= vui->virtio_net_hdr_sz;
846 bytes_left = b0->current_length;
852 if (desc_table[desc_index].flags & VRING_DESC_F_NEXT)
854 //Next one is chained
855 desc_index = desc_table[desc_index].next;
856 buffer_map_addr = desc_table[desc_index].addr;
857 buffer_len = desc_table[desc_index].len;
859 else if (vui->virtio_net_hdr_sz == 12) //MRG is available
861 virtio_net_hdr_mrg_rxbuf_t *hdr =
862 &cpu->tx_headers[tx_headers_len - 1];
864 //Move from available to used buffer
865 rxvq->used->ring[rxvq->last_used_idx & rxvq->qsz_mask].id =
867 rxvq->used->ring[rxvq->last_used_idx & rxvq->qsz_mask].len =
869 vhost_user_log_dirty_ring (vui, rxvq,
870 ring[rxvq->last_used_idx &
873 rxvq->last_avail_idx++;
874 rxvq->last_used_idx++;
879 (rxvq->last_avail_idx == rxvq->avail->idx))
881 //Dequeue queued descriptors for this packet
882 rxvq->last_used_idx -= hdr->num_buffers - 1;
883 rxvq->last_avail_idx -= hdr->num_buffers - 1;
884 error = VHOST_USER_TX_FUNC_ERROR_PKT_DROP_NOBUF;
888 desc_table = rxvq->desc;
889 desc_head = desc_index =
890 rxvq->avail->ring[rxvq->last_avail_idx & rxvq->qsz_mask];
892 (rxvq->desc[desc_head].flags & VRING_DESC_F_INDIRECT))
894 //It is seriously unlikely that a driver will put indirect descriptor
895 //after non-indirect descriptor.
897 (rxvq->desc[desc_head].len < sizeof (vring_desc_t)))
899 error = VHOST_USER_TX_FUNC_ERROR_INDIRECT_OVERFLOW;
905 rxvq->desc[desc_index].addr,
908 error = VHOST_USER_TX_FUNC_ERROR_MMAP_FAIL;
913 buffer_map_addr = desc_table[desc_index].addr;
914 buffer_len = desc_table[desc_index].len;
918 error = VHOST_USER_TX_FUNC_ERROR_PKT_DROP_NOMRG;
924 ASSERT (copy_len < VHOST_USER_COPY_ARRAY_N);
925 vhost_copy_t *cpy = &cpu->copy[copy_len];
927 cpy->len = bytes_left;
928 cpy->len = (cpy->len > buffer_len) ? buffer_len : cpy->len;
929 cpy->dst = buffer_map_addr;
930 cpy->src = (uword) vlib_buffer_get_current (current_b0) +
931 current_b0->current_length - bytes_left;
933 bytes_left -= cpy->len;
934 buffer_len -= cpy->len;
935 buffer_map_addr += cpy->len;
936 desc_len += cpy->len;
938 CLIB_PREFETCH (&rxvq->desc, CLIB_CACHE_LINE_BYTES, LOAD);
941 // Check if vlib buffer has more data. If not, get more or break.
942 if (PREDICT_TRUE (!bytes_left))
945 (current_b0->flags & VLIB_BUFFER_NEXT_PRESENT))
947 current_b0 = vlib_get_buffer (vm, current_b0->next_buffer);
948 bytes_left = current_b0->current_length;
958 //Move from available to used ring
959 rxvq->used->ring[rxvq->last_used_idx & rxvq->qsz_mask].id = desc_head;
960 rxvq->used->ring[rxvq->last_used_idx & rxvq->qsz_mask].len = desc_len;
961 vhost_user_log_dirty_ring (vui, rxvq,
962 ring[rxvq->last_used_idx & rxvq->qsz_mask]);
963 rxvq->last_avail_idx++;
964 rxvq->last_used_idx++;
966 if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
968 cpu->current_trace->hdr = cpu->tx_headers[tx_headers_len - 1];
971 n_left--; //At the end for error counting when 'goto done' is invoked
974 * Do the copy periodically to prevent
975 * cpu->copy array overflow and corrupt memory
977 if (PREDICT_FALSE (copy_len >= VHOST_USER_TX_COPY_THRESHOLD))
979 if (PREDICT_FALSE (vhost_user_tx_copy (vui, cpu->copy, copy_len,
982 vlib_error_count (vm, node->node_index,
983 VHOST_USER_TX_FUNC_ERROR_MMAP_FAIL, 1);
987 /* give buffers back to driver */
988 CLIB_MEMORY_BARRIER ();
989 rxvq->used->idx = rxvq->last_used_idx;
990 vhost_user_log_dirty_ring (vui, rxvq, idx);
996 //Do the memory copies
997 if (PREDICT_FALSE (vhost_user_tx_copy (vui, cpu->copy, copy_len,
1000 vlib_error_count (vm, node->node_index,
1001 VHOST_USER_TX_FUNC_ERROR_MMAP_FAIL, 1);
1004 CLIB_MEMORY_BARRIER ();
1005 rxvq->used->idx = rxvq->last_used_idx;
1006 vhost_user_log_dirty_ring (vui, rxvq, idx);
1009 * When n_left is set, error is always set to something too.
1010 * In case error is due to lack of remaining buffers, we go back up and
1012 * The idea is that it is better to waste some time on packets
1013 * that have been processed already than dropping them and get
1014 * more fresh packets with a good likelihood that they will be dropped too.
1015 * This technique also gives more time to VM driver to pick-up packets.
1016 * In case the traffic flows from physical to virtual interfaces, this
1017 * technique will end-up leveraging the physical NIC buffer in order to
1018 * absorb the VM's CPU jitter.
1020 if (n_left && (error == VHOST_USER_TX_FUNC_ERROR_PKT_DROP_NOBUF) && retry)
1026 /* interrupt (call) handling */
1027 if ((rxvq->callfd_idx != ~0) &&
1028 !(rxvq->avail->flags & VRING_AVAIL_F_NO_INTERRUPT))
1030 rxvq->n_since_last_int += frame->n_vectors - n_left;
1032 if (rxvq->n_since_last_int > vum->coalesce_frames)
1033 vhost_user_send_call (vm, rxvq);
1036 vhost_user_vring_unlock (vui, qid);
1039 if (PREDICT_FALSE (n_left && error != VHOST_USER_TX_FUNC_ERROR_NONE))
1041 vlib_error_count (vm, node->node_index, error, n_left);
1042 vlib_increment_simple_counter
1043 (vnet_main.interface_main.sw_if_counters
1044 + VNET_INTERFACE_COUNTER_DROP,
1045 thread_index, vui->sw_if_index, n_left);
1048 vlib_buffer_free (vm, vlib_frame_vector_args (frame), frame->n_vectors);
1049 return frame->n_vectors;
1052 static __clib_unused clib_error_t *
1053 vhost_user_interface_rx_mode_change (vnet_main_t * vnm, u32 hw_if_index,
1054 u32 qid, vnet_hw_if_rx_mode mode)
1056 vlib_main_t *vm = vnm->vlib_main;
1057 vnet_hw_interface_t *hif = vnet_get_hw_interface (vnm, hw_if_index);
1058 vhost_user_main_t *vum = &vhost_user_main;
1059 vhost_user_intf_t *vui =
1060 pool_elt_at_index (vum->vhost_user_interfaces, hif->dev_instance);
1061 vhost_user_vring_t *txvq = &vui->vrings[VHOST_VRING_IDX_TX (qid)];
1063 if ((mode == VNET_HW_IF_RX_MODE_INTERRUPT) ||
1064 (mode == VNET_HW_IF_RX_MODE_ADAPTIVE))
1066 if (txvq->kickfd_idx == ~0)
1068 // We cannot support interrupt mode if the driver opts out
1069 return clib_error_return (0, "Driver does not support interrupt");
1071 if (txvq->mode == VNET_HW_IF_RX_MODE_POLLING)
1074 // Start the timer if this is the first encounter on interrupt
1076 if ((vum->ifq_count == 1) &&
1077 (vum->coalesce_time > 0.0) && (vum->coalesce_frames > 0))
1078 vlib_process_signal_event (vm,
1079 vhost_user_send_interrupt_node.index,
1080 VHOST_USER_EVENT_START_TIMER, 0);
1083 else if (mode == VNET_HW_IF_RX_MODE_POLLING)
1085 if (((txvq->mode == VNET_HW_IF_RX_MODE_INTERRUPT) ||
1086 (txvq->mode == VNET_HW_IF_RX_MODE_ADAPTIVE)) && vum->ifq_count)
1089 // Stop the timer if there is no more interrupt interface/queue
1090 if ((vum->ifq_count == 0) &&
1091 (vum->coalesce_time > 0.0) && (vum->coalesce_frames > 0))
1092 vlib_process_signal_event (vm,
1093 vhost_user_send_interrupt_node.index,
1094 VHOST_USER_EVENT_STOP_TIMER, 0);
1099 if (mode == VNET_HW_IF_RX_MODE_POLLING)
1100 txvq->used->flags = VRING_USED_F_NO_NOTIFY;
1101 else if ((mode == VNET_HW_IF_RX_MODE_ADAPTIVE) ||
1102 (mode == VNET_HW_IF_RX_MODE_INTERRUPT))
1103 txvq->used->flags = 0;
1106 vu_log_err (vui, "unhandled mode %d changed for if %d queue %d", mode,
1108 return clib_error_return (0, "unsupported");
1114 static __clib_unused clib_error_t *
1115 vhost_user_interface_admin_up_down (vnet_main_t * vnm, u32 hw_if_index,
1118 vnet_hw_interface_t *hif = vnet_get_hw_interface (vnm, hw_if_index);
1119 vhost_user_main_t *vum = &vhost_user_main;
1120 vhost_user_intf_t *vui =
1121 pool_elt_at_index (vum->vhost_user_interfaces, hif->dev_instance);
1122 u8 link_old, link_new;
1124 link_old = vui_is_link_up (vui);
1126 vui->admin_up = (flags & VNET_SW_INTERFACE_FLAG_ADMIN_UP) != 0;
1128 link_new = vui_is_link_up (vui);
1130 if (link_old != link_new)
1131 vnet_hw_interface_set_flags (vnm, vui->hw_if_index, link_new ?
1132 VNET_HW_INTERFACE_FLAG_LINK_UP : 0);
1134 return /* no error */ 0;
1138 VNET_DEVICE_CLASS (vhost_user_device_class) = {
1139 .name = "vhost-user",
1140 .tx_function_n_errors = VHOST_USER_TX_FUNC_N_ERROR,
1141 .tx_function_error_strings = vhost_user_tx_func_error_strings,
1142 .format_device_name = format_vhost_user_interface_name,
1143 .name_renumber = vhost_user_name_renumber,
1144 .admin_up_down_function = vhost_user_interface_admin_up_down,
1145 .rx_mode_change_function = vhost_user_interface_rx_mode_change,
1146 .format_tx_trace = format_vhost_trace,
1152 * fd.io coding-style-patch-verification: ON
1155 * eval: (c-set-style "gnu")