lib/librte_vhost/vhost.c

   1 /* SPDX-License-Identifier: BSD-3-Clause
   2  * Copyright(c) 2010-2017 Intel Corporation
   3  */
   4
   5 #include <linux/vhost.h>
   6 #include <linux/virtio_net.h>
   7 #include <stddef.h>
   8 #include <stdint.h>
   9 #include <stdlib.h>
  10 #ifdef RTE_LIBRTE_VHOST_NUMA
  11 #include <numaif.h>
  12 #endif
  13
  14 #include <rte_errno.h>
  15 #include <rte_ethdev.h>
  16 #include <rte_log.h>
  17 #include <rte_string_fns.h>
  18 #include <rte_memory.h>
  19 #include <rte_malloc.h>
  20 #include <rte_vhost.h>
  21 #include <rte_rwlock.h>
  22
  23 #include "iotlb.h"
  24 #include "vhost.h"
  25 #include "vhost_user.h"
  26
  27 struct virtio_net *vhost_devices[MAX_VHOST_DEVICE];
  28
  29 /* Called with iotlb_lock read-locked */
  30 uint64_t
  31 __vhost_iova_to_vva(struct virtio_net *dev, struct vhost_virtqueue *vq,
  32                     uint64_t iova, uint64_t *size, uint8_t perm)
  33 {
  34         uint64_t vva, tmp_size;
  35
  36         if (unlikely(!*size))
  37                 return 0;
  38
  39         tmp_size = *size;
  40
  41         vva = vhost_user_iotlb_cache_find(vq, iova, &tmp_size, perm);
  42         if (tmp_size == *size)
  43                 return vva;
  44
  45         iova += tmp_size;
  46
  47         if (!vhost_user_iotlb_pending_miss(vq, iova, perm)) {
  48                 /*
  49                  * iotlb_lock is read-locked for a full burst,
  50                  * but it only protects the iotlb cache.
  51                  * In case of IOTLB miss, we might block on the socket,
  52                  * which could cause a deadlock with QEMU if an IOTLB update
  53                  * is being handled. We can safely unlock here to avoid it.
  54                  */
  55                 vhost_user_iotlb_rd_unlock(vq);
  56
  57                 vhost_user_iotlb_pending_insert(vq, iova, perm);
  58                 if (vhost_user_iotlb_miss(dev, iova, perm)) {
  59                         RTE_LOG(ERR, VHOST_CONFIG,
  60                                 "IOTLB miss req failed for IOVA 0x%" PRIx64 "\n",
  61                                 iova);
  62                         vhost_user_iotlb_pending_remove(vq, iova, 1, perm);
  63                 }
  64
  65                 vhost_user_iotlb_rd_lock(vq);
  66         }
  67
  68         return 0;
  69 }
  70
  71 void
  72 cleanup_vq(struct vhost_virtqueue *vq, int destroy)
  73 {
  74         if ((vq->callfd >= 0) && (destroy != 0))
  75                 close(vq->callfd);
  76         if (vq->kickfd >= 0)
  77                 close(vq->kickfd);
  78 }
  79
  80 /*
  81  * Unmap any memory, close any file descriptors and
  82  * free any memory owned by a device.
  83  */
  84 void
  85 cleanup_device(struct virtio_net *dev, int destroy)
  86 {
  87         uint32_t i;
  88
  89         vhost_backend_cleanup(dev);
  90
  91         for (i = 0; i < dev->nr_vring; i++)
  92                 cleanup_vq(dev->virtqueue[i], destroy);
  93 }
  94
  95 void
  96 free_vq(struct vhost_virtqueue *vq)
  97 {
  98         rte_free(vq->shadow_used_ring);
  99         rte_free(vq->batch_copy_elems);
 100         rte_mempool_free(vq->iotlb_pool);
 101         rte_free(vq);
 102 }
 103
 104 /*
 105  * Release virtqueues and device memory.
 106  */
 107 static void
 108 free_device(struct virtio_net *dev)
 109 {
 110         uint32_t i;
 111
 112         for (i = 0; i < dev->nr_vring; i++)
 113                 free_vq(dev->virtqueue[i]);
 114
 115         rte_free(dev);
 116 }
 117
 118 static int
 119 vring_translate_split(struct virtio_net *dev, struct vhost_virtqueue *vq)
 120 {
 121         uint64_t req_size, size;
 122
 123         req_size = sizeof(struct vring_desc) * vq->size;
 124         size = req_size;
 125         vq->desc = (struct vring_desc *)(uintptr_t)vhost_iova_to_vva(dev, vq,
 126                                                 vq->ring_addrs.desc_user_addr,
 127                                                 &size, VHOST_ACCESS_RW);
 128         if (!vq->desc || size != req_size)
 129                 return -1;
 130
 131         req_size = sizeof(struct vring_avail);
 132         req_size += sizeof(uint16_t) * vq->size;
 133         if (dev->features & (1ULL << VIRTIO_RING_F_EVENT_IDX))
 134                 req_size += sizeof(uint16_t);
 135         size = req_size;
 136         vq->avail = (struct vring_avail *)(uintptr_t)vhost_iova_to_vva(dev, vq,
 137                                                 vq->ring_addrs.avail_user_addr,
 138                                                 &size, VHOST_ACCESS_RW);
 139         if (!vq->avail || size != req_size)
 140                 return -1;
 141
 142         req_size = sizeof(struct vring_used);
 143         req_size += sizeof(struct vring_used_elem) * vq->size;
 144         if (dev->features & (1ULL << VIRTIO_RING_F_EVENT_IDX))
 145                 req_size += sizeof(uint16_t);
 146         size = req_size;
 147         vq->used = (struct vring_used *)(uintptr_t)vhost_iova_to_vva(dev, vq,
 148                                                 vq->ring_addrs.used_user_addr,
 149                                                 &size, VHOST_ACCESS_RW);
 150         if (!vq->used || size != req_size)
 151                 return -1;
 152
 153         return 0;
 154 }
 155
 156 static int
 157 vring_translate_packed(struct virtio_net *dev, struct vhost_virtqueue *vq)
 158 {
 159         uint64_t req_size, size;
 160
 161         req_size = sizeof(struct vring_packed_desc) * vq->size;
 162         size = req_size;
 163         vq->desc_packed =
 164                 (struct vring_packed_desc *)(uintptr_t)vhost_iova_to_vva(dev,
 165                                         vq, vq->ring_addrs.desc_user_addr,
 166                                         &size, VHOST_ACCESS_RW);
 167         if (!vq->desc_packed || size != req_size)
 168                 return -1;
 169
 170         return 0;
 171 }
 172
 173 int
 174 vring_translate(struct virtio_net *dev, struct vhost_virtqueue *vq)
 175 {
 176
 177         if (!(dev->features & (1ULL << VIRTIO_F_IOMMU_PLATFORM)))
 178                 goto out;
 179
 180         if (vq_is_packed(dev)) {
 181                 if (vring_translate_packed(dev, vq) < 0)
 182                         return -1;
 183         } else {
 184                 if (vring_translate_split(dev, vq) < 0)
 185                         return -1;
 186         }
 187 out:
 188         vq->access_ok = 1;
 189
 190         return 0;
 191 }
 192
 193 void
 194 vring_invalidate(struct virtio_net *dev, struct vhost_virtqueue *vq)
 195 {
 196         if (dev->features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))
 197                 vhost_user_iotlb_wr_lock(vq);
 198
 199         vq->access_ok = 0;
 200         vq->desc = NULL;
 201         vq->avail = NULL;
 202         vq->used = NULL;
 203
 204         if (dev->features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))
 205                 vhost_user_iotlb_wr_unlock(vq);
 206 }
 207
 208 static void
 209 init_vring_queue(struct virtio_net *dev, uint32_t vring_idx)
 210 {
 211         struct vhost_virtqueue *vq;
 212
 213         if (vring_idx >= VHOST_MAX_VRING) {
 214                 RTE_LOG(ERR, VHOST_CONFIG,
 215                                 "Failed not init vring, out of bound (%d)\n",
 216                                 vring_idx);
 217                 return;
 218         }
 219
 220         vq = dev->virtqueue[vring_idx];
 221
 222         memset(vq, 0, sizeof(struct vhost_virtqueue));
 223
 224         vq->kickfd = VIRTIO_UNINITIALIZED_EVENTFD;
 225         vq->callfd = VIRTIO_UNINITIALIZED_EVENTFD;
 226
 227         vhost_user_iotlb_init(dev, vring_idx);
 228         /* Backends are set to -1 indicating an inactive device. */
 229         vq->backend = -1;
 230
 231         TAILQ_INIT(&vq->zmbuf_list);
 232 }
 233
 234 static void
 235 reset_vring_queue(struct virtio_net *dev, uint32_t vring_idx)
 236 {
 237         struct vhost_virtqueue *vq;
 238         int callfd;
 239
 240         if (vring_idx >= VHOST_MAX_VRING) {
 241                 RTE_LOG(ERR, VHOST_CONFIG,
 242                                 "Failed not init vring, out of bound (%d)\n",
 243                                 vring_idx);
 244                 return;
 245         }
 246
 247         vq = dev->virtqueue[vring_idx];
 248         callfd = vq->callfd;
 249         init_vring_queue(dev, vring_idx);
 250         vq->callfd = callfd;
 251 }
 252
 253 int
 254 alloc_vring_queue(struct virtio_net *dev, uint32_t vring_idx)
 255 {
 256         struct vhost_virtqueue *vq;
 257
 258         vq = rte_malloc(NULL, sizeof(struct vhost_virtqueue), 0);
 259         if (vq == NULL) {
 260                 RTE_LOG(ERR, VHOST_CONFIG,
 261                         "Failed to allocate memory for vring:%u.\n", vring_idx);
 262                 return -1;
 263         }
 264
 265         dev->virtqueue[vring_idx] = vq;
 266         init_vring_queue(dev, vring_idx);
 267         rte_spinlock_init(&vq->access_lock);
 268         vq->avail_wrap_counter = 1;
 269         vq->used_wrap_counter = 1;
 270
 271         dev->nr_vring += 1;
 272
 273         return 0;
 274 }
 275
 276 /*
 277  * Reset some variables in device structure, while keeping few
 278  * others untouched, such as vid, ifname, nr_vring: they
 279  * should be same unless the device is removed.
 280  */
 281 void
 282 reset_device(struct virtio_net *dev)
 283 {
 284         uint32_t i;
 285
 286         dev->features = 0;
 287         dev->protocol_features = 0;
 288         dev->flags &= VIRTIO_DEV_BUILTIN_VIRTIO_NET;
 289
 290         for (i = 0; i < dev->nr_vring; i++)
 291                 reset_vring_queue(dev, i);
 292 }
 293
 294 /*
 295  * Invoked when there is a new vhost-user connection established (when
 296  * there is a new virtio device being attached).
 297  */
 298 int
 299 vhost_new_device(void)
 300 {
 301         struct virtio_net *dev;
 302         int i;
 303
 304         for (i = 0; i < MAX_VHOST_DEVICE; i++) {
 305                 if (vhost_devices[i] == NULL)
 306                         break;
 307         }
 308
 309         if (i == MAX_VHOST_DEVICE) {
 310                 RTE_LOG(ERR, VHOST_CONFIG,
 311                         "Failed to find a free slot for new device.\n");
 312                 return -1;
 313         }
 314
 315         dev = rte_zmalloc(NULL, sizeof(struct virtio_net), 0);
 316         if (dev == NULL) {
 317                 RTE_LOG(ERR, VHOST_CONFIG,
 318                         "Failed to allocate memory for new dev.\n");
 319                 return -1;
 320         }
 321
 322         vhost_devices[i] = dev;
 323         dev->vid = i;
 324         dev->flags = VIRTIO_DEV_BUILTIN_VIRTIO_NET;
 325         dev->slave_req_fd = -1;
 326         dev->vdpa_dev_id = -1;
 327         rte_spinlock_init(&dev->slave_req_lock);
 328
 329         return i;
 330 }
 331
 332 void
 333 vhost_destroy_device_notify(struct virtio_net *dev)
 334 {
 335         struct rte_vdpa_device *vdpa_dev;
 336         int did;
 337
 338         if (dev->flags & VIRTIO_DEV_RUNNING) {
 339                 did = dev->vdpa_dev_id;
 340                 vdpa_dev = rte_vdpa_get_device(did);
 341                 if (vdpa_dev && vdpa_dev->ops->dev_close)
 342                         vdpa_dev->ops->dev_close(dev->vid);
 343                 dev->flags &= ~VIRTIO_DEV_RUNNING;
 344                 dev->notify_ops->destroy_device(dev->vid);
 345         }
 346 }
 347
 348 /*
 349  * Invoked when there is the vhost-user connection is broken (when
 350  * the virtio device is being detached).
 351  */
 352 void
 353 vhost_destroy_device(int vid)
 354 {
 355         struct virtio_net *dev = get_device(vid);
 356
 357         if (dev == NULL)
 358                 return;
 359
 360         vhost_destroy_device_notify(dev);
 361
 362         cleanup_device(dev, 1);
 363         free_device(dev);
 364
 365         vhost_devices[vid] = NULL;
 366 }
 367
 368 void
 369 vhost_attach_vdpa_device(int vid, int did)
 370 {
 371         struct virtio_net *dev = get_device(vid);
 372
 373         if (dev == NULL)
 374                 return;
 375
 376         if (rte_vdpa_get_device(did) == NULL)
 377                 return;
 378
 379         dev->vdpa_dev_id = did;
 380 }
 381
 382 void
 383 vhost_detach_vdpa_device(int vid)
 384 {
 385         struct virtio_net *dev = get_device(vid);
 386
 387         if (dev == NULL)
 388                 return;
 389
 390         vhost_user_host_notifier_ctrl(vid, false);
 391
 392         dev->vdpa_dev_id = -1;
 393 }
 394
 395 void
 396 vhost_set_ifname(int vid, const char *if_name, unsigned int if_len)
 397 {
 398         struct virtio_net *dev;
 399         unsigned int len;
 400
 401         dev = get_device(vid);
 402         if (dev == NULL)
 403                 return;
 404
 405         len = if_len > sizeof(dev->ifname) ?
 406                 sizeof(dev->ifname) : if_len;
 407
 408         strncpy(dev->ifname, if_name, len);
 409         dev->ifname[sizeof(dev->ifname) - 1] = '\0';
 410 }
 411
 412 void
 413 vhost_enable_dequeue_zero_copy(int vid)
 414 {
 415         struct virtio_net *dev = get_device(vid);
 416
 417         if (dev == NULL)
 418                 return;
 419
 420         dev->dequeue_zero_copy = 1;
 421 }
 422
 423 void
 424 vhost_set_builtin_virtio_net(int vid, bool enable)
 425 {
 426         struct virtio_net *dev = get_device(vid);
 427
 428         if (dev == NULL)
 429                 return;
 430
 431         if (enable)
 432                 dev->flags |= VIRTIO_DEV_BUILTIN_VIRTIO_NET;
 433         else
 434                 dev->flags &= ~VIRTIO_DEV_BUILTIN_VIRTIO_NET;
 435 }
 436
 437 int
 438 rte_vhost_get_mtu(int vid, uint16_t *mtu)
 439 {
 440         struct virtio_net *dev = get_device(vid);
 441
 442         if (!dev)
 443                 return -ENODEV;
 444
 445         if (!(dev->flags & VIRTIO_DEV_READY))
 446                 return -EAGAIN;
 447
 448         if (!(dev->features & (1ULL << VIRTIO_NET_F_MTU)))
 449                 return -ENOTSUP;
 450
 451         *mtu = dev->mtu;
 452
 453         return 0;
 454 }
 455
 456 int
 457 rte_vhost_get_numa_node(int vid)
 458 {
 459 #ifdef RTE_LIBRTE_VHOST_NUMA
 460         struct virtio_net *dev = get_device(vid);
 461         int numa_node;
 462         int ret;
 463
 464         if (dev == NULL)
 465                 return -1;
 466
 467         ret = get_mempolicy(&numa_node, NULL, 0, dev,
 468                             MPOL_F_NODE | MPOL_F_ADDR);
 469         if (ret < 0) {
 470                 RTE_LOG(ERR, VHOST_CONFIG,
 471                         "(%d) failed to query numa node: %s\n",
 472                         vid, rte_strerror(errno));
 473                 return -1;
 474         }
 475
 476         return numa_node;
 477 #else
 478         RTE_SET_USED(vid);
 479         return -1;
 480 #endif
 481 }
 482
 483 uint32_t
 484 rte_vhost_get_queue_num(int vid)
 485 {
 486         struct virtio_net *dev = get_device(vid);
 487
 488         if (dev == NULL)
 489                 return 0;
 490
 491         return dev->nr_vring / 2;
 492 }
 493
 494 uint16_t
 495 rte_vhost_get_vring_num(int vid)
 496 {
 497         struct virtio_net *dev = get_device(vid);
 498
 499         if (dev == NULL)
 500                 return 0;
 501
 502         return dev->nr_vring;
 503 }
 504
 505 int
 506 rte_vhost_get_ifname(int vid, char *buf, size_t len)
 507 {
 508         struct virtio_net *dev = get_device(vid);
 509
 510         if (dev == NULL)
 511                 return -1;
 512
 513         len = RTE_MIN(len, sizeof(dev->ifname));
 514
 515         strncpy(buf, dev->ifname, len);
 516         buf[len - 1] = '\0';
 517
 518         return 0;
 519 }
 520
 521 int
 522 rte_vhost_get_negotiated_features(int vid, uint64_t *features)
 523 {
 524         struct virtio_net *dev;
 525
 526         dev = get_device(vid);
 527         if (!dev)
 528                 return -1;
 529
 530         *features = dev->features;
 531         return 0;
 532 }
 533
 534 int
 535 rte_vhost_get_mem_table(int vid, struct rte_vhost_memory **mem)
 536 {
 537         struct virtio_net *dev;
 538         struct rte_vhost_memory *m;
 539         size_t size;
 540
 541         dev = get_device(vid);
 542         if (!dev)
 543                 return -1;
 544
 545         size = dev->mem->nregions * sizeof(struct rte_vhost_mem_region);
 546         m = malloc(sizeof(struct rte_vhost_memory) + size);
 547         if (!m)
 548                 return -1;
 549
 550         m->nregions = dev->mem->nregions;
 551         memcpy(m->regions, dev->mem->regions, size);
 552         *mem = m;
 553
 554         return 0;
 555 }
 556
 557 int
 558 rte_vhost_get_vhost_vring(int vid, uint16_t vring_idx,
 559                           struct rte_vhost_vring *vring)
 560 {
 561         struct virtio_net *dev;
 562         struct vhost_virtqueue *vq;
 563
 564         dev = get_device(vid);
 565         if (!dev)
 566                 return -1;
 567
 568         if (vring_idx >= VHOST_MAX_VRING)
 569                 return -1;
 570
 571         vq = dev->virtqueue[vring_idx];
 572         if (!vq)
 573                 return -1;
 574
 575         vring->desc  = vq->desc;
 576         vring->avail = vq->avail;
 577         vring->used  = vq->used;
 578         vring->log_guest_addr  = vq->log_guest_addr;
 579
 580         vring->callfd  = vq->callfd;
 581         vring->kickfd  = vq->kickfd;
 582         vring->size    = vq->size;
 583
 584         return 0;
 585 }
 586
 587 int
 588 rte_vhost_vring_call(int vid, uint16_t vring_idx)
 589 {
 590         struct virtio_net *dev;
 591         struct vhost_virtqueue *vq;
 592
 593         dev = get_device(vid);
 594         if (!dev)
 595                 return -1;
 596
 597         if (vring_idx >= VHOST_MAX_VRING)
 598                 return -1;
 599
 600         vq = dev->virtqueue[vring_idx];
 601         if (!vq)
 602                 return -1;
 603
 604         vhost_vring_call(dev, vq);
 605         return 0;
 606 }
 607
 608 uint16_t
 609 rte_vhost_avail_entries(int vid, uint16_t queue_id)
 610 {
 611         struct virtio_net *dev;
 612         struct vhost_virtqueue *vq;
 613
 614         dev = get_device(vid);
 615         if (!dev)
 616                 return 0;
 617
 618         vq = dev->virtqueue[queue_id];
 619         if (!vq->enabled)
 620                 return 0;
 621
 622         return *(volatile uint16_t *)&vq->avail->idx - vq->last_used_idx;
 623 }
 624
 625 int
 626 rte_vhost_enable_guest_notification(int vid, uint16_t queue_id, int enable)
 627 {
 628         struct virtio_net *dev = get_device(vid);
 629
 630         if (!dev)
 631                 return -1;
 632
 633         if (enable)
 634                 dev->virtqueue[queue_id]->used->flags &=
 635                         ~VRING_USED_F_NO_NOTIFY;
 636         else
 637                 dev->virtqueue[queue_id]->used->flags |= VRING_USED_F_NO_NOTIFY;
 638         return 0;
 639 }
 640
 641 void
 642 rte_vhost_log_write(int vid, uint64_t addr, uint64_t len)
 643 {
 644         struct virtio_net *dev = get_device(vid);
 645
 646         if (dev == NULL)
 647                 return;
 648
 649         vhost_log_write(dev, addr, len);
 650 }
 651
 652 void
 653 rte_vhost_log_used_vring(int vid, uint16_t vring_idx,
 654                          uint64_t offset, uint64_t len)
 655 {
 656         struct virtio_net *dev;
 657         struct vhost_virtqueue *vq;
 658
 659         dev = get_device(vid);
 660         if (dev == NULL)
 661                 return;
 662
 663         if (vring_idx >= VHOST_MAX_VRING)
 664                 return;
 665         vq = dev->virtqueue[vring_idx];
 666         if (!vq)
 667                 return;
 668
 669         vhost_log_used_vring(dev, vq, offset, len);
 670 }
 671
 672 uint32_t
 673 rte_vhost_rx_queue_count(int vid, uint16_t qid)
 674 {
 675         struct virtio_net *dev;
 676         struct vhost_virtqueue *vq;
 677
 678         dev = get_device(vid);
 679         if (dev == NULL)
 680                 return 0;
 681
 682         if (unlikely(qid >= dev->nr_vring || (qid & 1) == 0)) {
 683                 RTE_LOG(ERR, VHOST_DATA, "(%d) %s: invalid virtqueue idx %d.\n",
 684                         dev->vid, __func__, qid);
 685                 return 0;
 686         }
 687
 688         vq = dev->virtqueue[qid];
 689         if (vq == NULL)
 690                 return 0;
 691
 692         if (unlikely(vq->enabled == 0 || vq->avail == NULL))
 693                 return 0;
 694
 695         return *((volatile uint16_t *)&vq->avail->idx) - vq->last_avail_idx;
 696 }
 697
 698 int rte_vhost_get_vdpa_device_id(int vid)
 699 {
 700         struct virtio_net *dev = get_device(vid);
 701
 702         if (dev == NULL)
 703                 return -1;
 704
 705         return dev->vdpa_dev_id;
 706 }
 707
 708 int rte_vhost_get_log_base(int vid, uint64_t *log_base,
 709                 uint64_t *log_size)
 710 {
 711         struct virtio_net *dev = get_device(vid);
 712
 713         if (!dev)
 714                 return -1;
 715
 716         if (unlikely(!(dev->flags & VIRTIO_DEV_BUILTIN_VIRTIO_NET))) {
 717                 RTE_LOG(ERR, VHOST_DATA,
 718                         "(%d) %s: built-in vhost net backend is disabled.\n",
 719                         dev->vid, __func__);
 720                 return -1;
 721         }
 722
 723         *log_base = dev->log_base;
 724         *log_size = dev->log_size;
 725
 726         return 0;
 727 }
 728
 729 int rte_vhost_get_vring_base(int vid, uint16_t queue_id,
 730                 uint16_t *last_avail_idx, uint16_t *last_used_idx)
 731 {
 732         struct virtio_net *dev = get_device(vid);
 733
 734         if (!dev)
 735                 return -1;
 736
 737         if (unlikely(!(dev->flags & VIRTIO_DEV_BUILTIN_VIRTIO_NET))) {
 738                 RTE_LOG(ERR, VHOST_DATA,
 739                         "(%d) %s: built-in vhost net backend is disabled.\n",
 740                         dev->vid, __func__);
 741                 return -1;
 742         }
 743
 744         *last_avail_idx = dev->virtqueue[queue_id]->last_avail_idx;
 745         *last_used_idx = dev->virtqueue[queue_id]->last_used_idx;
 746
 747         return 0;
 748 }
 749
 750 int rte_vhost_set_vring_base(int vid, uint16_t queue_id,
 751                 uint16_t last_avail_idx, uint16_t last_used_idx)
 752 {
 753         struct virtio_net *dev = get_device(vid);
 754
 755         if (!dev)
 756                 return -1;
 757
 758         if (unlikely(!(dev->flags & VIRTIO_DEV_BUILTIN_VIRTIO_NET))) {
 759                 RTE_LOG(ERR, VHOST_DATA,
 760                         "(%d) %s: built-in vhost net backend is disabled.\n",
 761                         dev->vid, __func__);
 762                 return -1;
 763         }
 764
 765         dev->virtqueue[queue_id]->last_avail_idx = last_avail_idx;
 766         dev->virtqueue[queue_id]->last_used_idx = last_used_idx;
 767
 768         return 0;
 769 }