lib/librte_vhost/virtio_net.c

   1 /*-
   2  *   BSD LICENSE
   3  *
   4  *   Copyright(c) 2010-2016 Intel Corporation. All rights reserved.
   5  *   All rights reserved.
   6  *
   7  *   Redistribution and use in source and binary forms, with or without
   8  *   modification, are permitted provided that the following conditions
   9  *   are met:
  10  *
  11  *     * Redistributions of source code must retain the above copyright
  12  *       notice, this list of conditions and the following disclaimer.
  13  *     * Redistributions in binary form must reproduce the above copyright
  14  *       notice, this list of conditions and the following disclaimer in
  15  *       the documentation and/or other materials provided with the
  16  *       distribution.
  17  *     * Neither the name of Intel Corporation nor the names of its
  18  *       contributors may be used to endorse or promote products derived
  19  *       from this software without specific prior written permission.
  20  *
  21  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  22  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  23  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  24  *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  25  *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  26  *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  27  *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  28  *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  29  *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  30  *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  31  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  32  */
  33
  34 #include <stdint.h>
  35 #include <stdbool.h>
  36 #include <linux/virtio_net.h>
  37
  38 #include <rte_mbuf.h>
  39 #include <rte_memcpy.h>
  40 #include <rte_ether.h>
  41 #include <rte_ip.h>
  42 #include <rte_virtio_net.h>
  43 #include <rte_tcp.h>
  44 #include <rte_udp.h>
  45 #include <rte_sctp.h>
  46 #include <rte_arp.h>
  47
  48 #include "vhost.h"
  49
  50 #define MAX_PKT_BURST 32
  51 #define VHOST_LOG_PAGE  4096
  52
  53 static inline void __attribute__((always_inline))
  54 vhost_log_page(uint8_t *log_base, uint64_t page)
  55 {
  56         log_base[page / 8] |= 1 << (page % 8);
  57 }
  58
  59 static inline void __attribute__((always_inline))
  60 vhost_log_write(struct virtio_net *dev, uint64_t addr, uint64_t len)
  61 {
  62         uint64_t page;
  63
  64         if (likely(((dev->features & (1ULL << VHOST_F_LOG_ALL)) == 0) ||
  65                    !dev->log_base || !len))
  66                 return;
  67
  68         if (unlikely(dev->log_size <= ((addr + len - 1) / VHOST_LOG_PAGE / 8)))
  69                 return;
  70
  71         /* To make sure guest memory updates are committed before logging */
  72         rte_smp_wmb();
  73
  74         page = addr / VHOST_LOG_PAGE;
  75         while (page * VHOST_LOG_PAGE < addr + len) {
  76                 vhost_log_page((uint8_t *)(uintptr_t)dev->log_base, page);
  77                 page += 1;
  78         }
  79 }
  80
  81 static inline void __attribute__((always_inline))
  82 vhost_log_used_vring(struct virtio_net *dev, struct vhost_virtqueue *vq,
  83                      uint64_t offset, uint64_t len)
  84 {
  85         vhost_log_write(dev, vq->log_guest_addr + offset, len);
  86 }
  87
  88 static bool
  89 is_valid_virt_queue_idx(uint32_t idx, int is_tx, uint32_t qp_nb)
  90 {
  91         return (is_tx ^ (idx & 1)) == 0 && idx < qp_nb * VIRTIO_QNUM;
  92 }
  93
  94 static inline void __attribute__((always_inline))
  95 do_flush_shadow_used_ring(struct virtio_net *dev, struct vhost_virtqueue *vq,
  96                           uint16_t to, uint16_t from, uint16_t size)
  97 {
  98         rte_memcpy(&vq->used->ring[to],
  99                         &vq->shadow_used_ring[from],
 100                         size * sizeof(struct vring_used_elem));
 101         vhost_log_used_vring(dev, vq,
 102                         offsetof(struct vring_used, ring[to]),
 103                         size * sizeof(struct vring_used_elem));
 104 }
 105
 106 static inline void __attribute__((always_inline))
 107 flush_shadow_used_ring(struct virtio_net *dev, struct vhost_virtqueue *vq)
 108 {
 109         uint16_t used_idx = vq->last_used_idx & (vq->size - 1);
 110
 111         if (used_idx + vq->shadow_used_idx <= vq->size) {
 112                 do_flush_shadow_used_ring(dev, vq, used_idx, 0,
 113                                           vq->shadow_used_idx);
 114         } else {
 115                 uint16_t size;
 116
 117                 /* update used ring interval [used_idx, vq->size] */
 118                 size = vq->size - used_idx;
 119                 do_flush_shadow_used_ring(dev, vq, used_idx, 0, size);
 120
 121                 /* update the left half used ring interval [0, left_size] */
 122                 do_flush_shadow_used_ring(dev, vq, 0, size,
 123                                           vq->shadow_used_idx - size);
 124         }
 125         vq->last_used_idx += vq->shadow_used_idx;
 126
 127         rte_smp_wmb();
 128
 129         *(volatile uint16_t *)&vq->used->idx += vq->shadow_used_idx;
 130         vhost_log_used_vring(dev, vq, offsetof(struct vring_used, idx),
 131                 sizeof(vq->used->idx));
 132 }
 133
 134 static inline void __attribute__((always_inline))
 135 update_shadow_used_ring(struct vhost_virtqueue *vq,
 136                          uint16_t desc_idx, uint16_t len)
 137 {
 138         uint16_t i = vq->shadow_used_idx++;
 139
 140         vq->shadow_used_ring[i].id  = desc_idx;
 141         vq->shadow_used_ring[i].len = len;
 142 }
 143
 144 static void
 145 virtio_enqueue_offload(struct rte_mbuf *m_buf, struct virtio_net_hdr *net_hdr)
 146 {
 147         if (m_buf->ol_flags & PKT_TX_L4_MASK) {
 148                 net_hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
 149                 net_hdr->csum_start = m_buf->l2_len + m_buf->l3_len;
 150
 151                 switch (m_buf->ol_flags & PKT_TX_L4_MASK) {
 152                 case PKT_TX_TCP_CKSUM:
 153                         net_hdr->csum_offset = (offsetof(struct tcp_hdr,
 154                                                 cksum));
 155                         break;
 156                 case PKT_TX_UDP_CKSUM:
 157                         net_hdr->csum_offset = (offsetof(struct udp_hdr,
 158                                                 dgram_cksum));
 159                         break;
 160                 case PKT_TX_SCTP_CKSUM:
 161                         net_hdr->csum_offset = (offsetof(struct sctp_hdr,
 162                                                 cksum));
 163                         break;
 164                 }
 165         }
 166
 167         if (m_buf->ol_flags & PKT_TX_TCP_SEG) {
 168                 if (m_buf->ol_flags & PKT_TX_IPV4)
 169                         net_hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
 170                 else
 171                         net_hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
 172                 net_hdr->gso_size = m_buf->tso_segsz;
 173                 net_hdr->hdr_len = m_buf->l2_len + m_buf->l3_len
 174                                         + m_buf->l4_len;
 175         }
 176 }
 177
 178 static inline void
 179 copy_virtio_net_hdr(struct virtio_net *dev, uint64_t desc_addr,
 180                     struct virtio_net_hdr_mrg_rxbuf hdr)
 181 {
 182         if (dev->vhost_hlen == sizeof(struct virtio_net_hdr_mrg_rxbuf))
 183                 *(struct virtio_net_hdr_mrg_rxbuf *)(uintptr_t)desc_addr = hdr;
 184         else
 185                 *(struct virtio_net_hdr *)(uintptr_t)desc_addr = hdr.hdr;
 186 }
 187
 188 static inline int __attribute__((always_inline))
 189 copy_mbuf_to_desc(struct virtio_net *dev, struct vhost_virtqueue *vq,
 190                   struct rte_mbuf *m, uint16_t desc_idx)
 191 {
 192         uint32_t desc_avail, desc_offset;
 193         uint32_t mbuf_avail, mbuf_offset;
 194         uint32_t cpy_len;
 195         struct vring_desc *desc;
 196         uint64_t desc_addr;
 197         struct virtio_net_hdr_mrg_rxbuf virtio_hdr = {{0, 0, 0, 0, 0, 0}, 0};
 198
 199         desc = &vq->desc[desc_idx];
 200         desc_addr = gpa_to_vva(dev, desc->addr);
 201         /*
 202          * Checking of 'desc_addr' placed outside of 'unlikely' macro to avoid
 203          * performance issue with some versions of gcc (4.8.4 and 5.3.0) which
 204          * otherwise stores offset on the stack instead of in a register.
 205          */
 206         if (unlikely(desc->len < dev->vhost_hlen) || !desc_addr)
 207                 return -1;
 208
 209         rte_prefetch0((void *)(uintptr_t)desc_addr);
 210
 211         virtio_enqueue_offload(m, &virtio_hdr.hdr);
 212         copy_virtio_net_hdr(dev, desc_addr, virtio_hdr);
 213         vhost_log_write(dev, desc->addr, dev->vhost_hlen);
 214         PRINT_PACKET(dev, (uintptr_t)desc_addr, dev->vhost_hlen, 0);
 215
 216         desc_offset = dev->vhost_hlen;
 217         desc_avail  = desc->len - dev->vhost_hlen;
 218
 219         mbuf_avail  = rte_pktmbuf_data_len(m);
 220         mbuf_offset = 0;
 221         while (mbuf_avail != 0 || m->next != NULL) {
 222                 /* done with current mbuf, fetch next */
 223                 if (mbuf_avail == 0) {
 224                         m = m->next;
 225
 226                         mbuf_offset = 0;
 227                         mbuf_avail  = rte_pktmbuf_data_len(m);
 228                 }
 229
 230                 /* done with current desc buf, fetch next */
 231                 if (desc_avail == 0) {
 232                         if ((desc->flags & VRING_DESC_F_NEXT) == 0) {
 233                                 /* Room in vring buffer is not enough */
 234                                 return -1;
 235                         }
 236                         if (unlikely(desc->next >= vq->size))
 237                                 return -1;
 238
 239                         desc = &vq->desc[desc->next];
 240                         desc_addr = gpa_to_vva(dev, desc->addr);
 241                         if (unlikely(!desc_addr))
 242                                 return -1;
 243
 244                         desc_offset = 0;
 245                         desc_avail  = desc->len;
 246                 }
 247
 248                 cpy_len = RTE_MIN(desc_avail, mbuf_avail);
 249                 rte_memcpy((void *)((uintptr_t)(desc_addr + desc_offset)),
 250                         rte_pktmbuf_mtod_offset(m, void *, mbuf_offset),
 251                         cpy_len);
 252                 vhost_log_write(dev, desc->addr + desc_offset, cpy_len);
 253                 PRINT_PACKET(dev, (uintptr_t)(desc_addr + desc_offset),
 254                              cpy_len, 0);
 255
 256                 mbuf_avail  -= cpy_len;
 257                 mbuf_offset += cpy_len;
 258                 desc_avail  -= cpy_len;
 259                 desc_offset += cpy_len;
 260         }
 261
 262         return 0;
 263 }
 264
 265 /**
 266  * This function adds buffers to the virtio devices RX virtqueue. Buffers can
 267  * be received from the physical port or from another virtio device. A packet
 268  * count is returned to indicate the number of packets that are succesfully
 269  * added to the RX queue. This function works when the mbuf is scattered, but
 270  * it doesn't support the mergeable feature.
 271  */
 272 static inline uint32_t __attribute__((always_inline))
 273 virtio_dev_rx(struct virtio_net *dev, uint16_t queue_id,
 274               struct rte_mbuf **pkts, uint32_t count)
 275 {
 276         struct vhost_virtqueue *vq;
 277         uint16_t avail_idx, free_entries, start_idx;
 278         uint16_t desc_indexes[MAX_PKT_BURST];
 279         uint16_t used_idx;
 280         uint32_t i;
 281
 282         LOG_DEBUG(VHOST_DATA, "(%d) %s\n", dev->vid, __func__);
 283         if (unlikely(!is_valid_virt_queue_idx(queue_id, 0, dev->virt_qp_nb))) {
 284                 RTE_LOG(ERR, VHOST_DATA, "(%d) %s: invalid virtqueue idx %d.\n",
 285                         dev->vid, __func__, queue_id);
 286                 return 0;
 287         }
 288
 289         vq = dev->virtqueue[queue_id];
 290         if (unlikely(vq->enabled == 0))
 291                 return 0;
 292
 293         avail_idx = *((volatile uint16_t *)&vq->avail->idx);
 294         start_idx = vq->last_used_idx;
 295         free_entries = avail_idx - start_idx;
 296         count = RTE_MIN(count, free_entries);
 297         count = RTE_MIN(count, (uint32_t)MAX_PKT_BURST);
 298         if (count == 0)
 299                 return 0;
 300
 301         LOG_DEBUG(VHOST_DATA, "(%d) start_idx %d | end_idx %d\n",
 302                 dev->vid, start_idx, start_idx + count);
 303
 304         /* Retrieve all of the desc indexes first to avoid caching issues. */
 305         rte_prefetch0(&vq->avail->ring[start_idx & (vq->size - 1)]);
 306         for (i = 0; i < count; i++) {
 307                 used_idx = (start_idx + i) & (vq->size - 1);
 308                 desc_indexes[i] = vq->avail->ring[used_idx];
 309                 vq->used->ring[used_idx].id = desc_indexes[i];
 310                 vq->used->ring[used_idx].len = pkts[i]->pkt_len +
 311                                                dev->vhost_hlen;
 312                 vhost_log_used_vring(dev, vq,
 313                         offsetof(struct vring_used, ring[used_idx]),
 314                         sizeof(vq->used->ring[used_idx]));
 315         }
 316
 317         rte_prefetch0(&vq->desc[desc_indexes[0]]);
 318         for (i = 0; i < count; i++) {
 319                 uint16_t desc_idx = desc_indexes[i];
 320                 int err;
 321
 322                 err = copy_mbuf_to_desc(dev, vq, pkts[i], desc_idx);
 323                 if (unlikely(err)) {
 324                         used_idx = (start_idx + i) & (vq->size - 1);
 325                         vq->used->ring[used_idx].len = dev->vhost_hlen;
 326                         vhost_log_used_vring(dev, vq,
 327                                 offsetof(struct vring_used, ring[used_idx]),
 328                                 sizeof(vq->used->ring[used_idx]));
 329                 }
 330
 331                 if (i + 1 < count)
 332                         rte_prefetch0(&vq->desc[desc_indexes[i+1]]);
 333         }
 334
 335         rte_smp_wmb();
 336
 337         *(volatile uint16_t *)&vq->used->idx += count;
 338         vq->last_used_idx += count;
 339         vhost_log_used_vring(dev, vq,
 340                 offsetof(struct vring_used, idx),
 341                 sizeof(vq->used->idx));
 342
 343         /* flush used->idx update before we read avail->flags. */
 344         rte_mb();
 345
 346         /* Kick the guest if necessary. */
 347         if (!(vq->avail->flags & VRING_AVAIL_F_NO_INTERRUPT)
 348                         && (vq->callfd >= 0))
 349                 eventfd_write(vq->callfd, (eventfd_t)1);
 350         return count;
 351 }
 352
 353 static inline int __attribute__((always_inline))
 354 fill_vec_buf(struct virtio_net *dev, struct vhost_virtqueue *vq,
 355                          uint32_t avail_idx, uint32_t *vec_idx,
 356                          struct buf_vector *buf_vec, uint16_t *desc_chain_head,
 357                          uint16_t *desc_chain_len)
 358 {
 359         uint16_t idx = vq->avail->ring[avail_idx & (vq->size - 1)];
 360         uint32_t vec_id = *vec_idx;
 361         uint32_t len    = 0;
 362         struct vring_desc *descs = vq->desc;
 363
 364         *desc_chain_head = idx;
 365
 366         if (vq->desc[idx].flags & VRING_DESC_F_INDIRECT) {
 367                 descs = (struct vring_desc *)(uintptr_t)
 368                                         gpa_to_vva(dev, vq->desc[idx].addr);
 369                 if (unlikely(!descs))
 370                         return -1;
 371
 372                 idx = 0;
 373         }
 374
 375         while (1) {
 376                 if (unlikely(vec_id >= BUF_VECTOR_MAX || idx >= vq->size))
 377                         return -1;
 378
 379                 len += descs[idx].len;
 380                 buf_vec[vec_id].buf_addr = descs[idx].addr;
 381                 buf_vec[vec_id].buf_len  = descs[idx].len;
 382                 buf_vec[vec_id].desc_idx = idx;
 383                 vec_id++;
 384
 385                 if ((descs[idx].flags & VRING_DESC_F_NEXT) == 0)
 386                         break;
 387
 388                 idx = descs[idx].next;
 389         }
 390
 391         *desc_chain_len = len;
 392         *vec_idx = vec_id;
 393
 394         return 0;
 395 }
 396
 397 /*
 398  * Returns -1 on fail, 0 on success
 399  */
 400 static inline int
 401 reserve_avail_buf_mergeable(struct virtio_net *dev, struct vhost_virtqueue *vq,
 402                                 uint32_t size, struct buf_vector *buf_vec,
 403                                 uint16_t *num_buffers, uint16_t avail_head)
 404 {
 405         uint16_t cur_idx;
 406         uint32_t vec_idx = 0;
 407         uint16_t tries = 0;
 408
 409         uint16_t head_idx = 0;
 410         uint16_t len = 0;
 411
 412         *num_buffers = 0;
 413         cur_idx  = vq->last_avail_idx;
 414
 415         while (size > 0) {
 416                 if (unlikely(cur_idx == avail_head))
 417                         return -1;
 418
 419                 if (unlikely(fill_vec_buf(dev, vq, cur_idx, &vec_idx, buf_vec,
 420                                                 &head_idx, &len) < 0))
 421                         return -1;
 422                 len = RTE_MIN(len, size);
 423                 update_shadow_used_ring(vq, head_idx, len);
 424                 size -= len;
 425
 426                 cur_idx++;
 427                 tries++;
 428                 *num_buffers += 1;
 429
 430                 /*
 431                  * if we tried all available ring items, and still
 432                  * can't get enough buf, it means something abnormal
 433                  * happened.
 434                  */
 435                 if (unlikely(tries >= vq->size))
 436                         return -1;
 437         }
 438
 439         return 0;
 440 }
 441
 442 static inline int __attribute__((always_inline))
 443 copy_mbuf_to_desc_mergeable(struct virtio_net *dev, struct rte_mbuf *m,
 444                             struct buf_vector *buf_vec, uint16_t num_buffers)
 445 {
 446         struct virtio_net_hdr_mrg_rxbuf virtio_hdr = {{0, 0, 0, 0, 0, 0}, 0};
 447         uint32_t vec_idx = 0;
 448         uint64_t desc_addr;
 449         uint32_t mbuf_offset, mbuf_avail;
 450         uint32_t desc_offset, desc_avail;
 451         uint32_t cpy_len;
 452         uint64_t hdr_addr, hdr_phys_addr;
 453         struct rte_mbuf *hdr_mbuf;
 454
 455         if (unlikely(m == NULL))
 456                 return -1;
 457
 458         desc_addr = gpa_to_vva(dev, buf_vec[vec_idx].buf_addr);
 459         if (buf_vec[vec_idx].buf_len < dev->vhost_hlen || !desc_addr)
 460                 return -1;
 461
 462         hdr_mbuf = m;
 463         hdr_addr = desc_addr;
 464         hdr_phys_addr = buf_vec[vec_idx].buf_addr;
 465         rte_prefetch0((void *)(uintptr_t)hdr_addr);
 466
 467         virtio_hdr.num_buffers = num_buffers;
 468         LOG_DEBUG(VHOST_DATA, "(%d) RX: num merge buffers %d\n",
 469                 dev->vid, num_buffers);
 470
 471         desc_avail  = buf_vec[vec_idx].buf_len - dev->vhost_hlen;
 472         desc_offset = dev->vhost_hlen;
 473
 474         mbuf_avail  = rte_pktmbuf_data_len(m);
 475         mbuf_offset = 0;
 476         while (mbuf_avail != 0 || m->next != NULL) {
 477                 /* done with current desc buf, get the next one */
 478                 if (desc_avail == 0) {
 479                         vec_idx++;
 480                         desc_addr = gpa_to_vva(dev, buf_vec[vec_idx].buf_addr);
 481                         if (unlikely(!desc_addr))
 482                                 return -1;
 483
 484                         /* Prefetch buffer address. */
 485                         rte_prefetch0((void *)(uintptr_t)desc_addr);
 486                         desc_offset = 0;
 487                         desc_avail  = buf_vec[vec_idx].buf_len;
 488                 }
 489
 490                 /* done with current mbuf, get the next one */
 491                 if (mbuf_avail == 0) {
 492                         m = m->next;
 493
 494                         mbuf_offset = 0;
 495                         mbuf_avail  = rte_pktmbuf_data_len(m);
 496                 }
 497
 498                 if (hdr_addr) {
 499                         virtio_enqueue_offload(hdr_mbuf, &virtio_hdr.hdr);
 500                         copy_virtio_net_hdr(dev, hdr_addr, virtio_hdr);
 501                         vhost_log_write(dev, hdr_phys_addr, dev->vhost_hlen);
 502                         PRINT_PACKET(dev, (uintptr_t)hdr_addr,
 503                                      dev->vhost_hlen, 0);
 504
 505                         hdr_addr = 0;
 506                 }
 507
 508                 cpy_len = RTE_MIN(desc_avail, mbuf_avail);
 509                 rte_memcpy((void *)((uintptr_t)(desc_addr + desc_offset)),
 510                         rte_pktmbuf_mtod_offset(m, void *, mbuf_offset),
 511                         cpy_len);
 512                 vhost_log_write(dev, buf_vec[vec_idx].buf_addr + desc_offset,
 513                         cpy_len);
 514                 PRINT_PACKET(dev, (uintptr_t)(desc_addr + desc_offset),
 515                         cpy_len, 0);
 516
 517                 mbuf_avail  -= cpy_len;
 518                 mbuf_offset += cpy_len;
 519                 desc_avail  -= cpy_len;
 520                 desc_offset += cpy_len;
 521         }
 522
 523         return 0;
 524 }
 525
 526 static inline uint32_t __attribute__((always_inline))
 527 virtio_dev_merge_rx(struct virtio_net *dev, uint16_t queue_id,
 528         struct rte_mbuf **pkts, uint32_t count)
 529 {
 530         struct vhost_virtqueue *vq;
 531         uint32_t pkt_idx = 0;
 532         uint16_t num_buffers;
 533         struct buf_vector buf_vec[BUF_VECTOR_MAX];
 534         uint16_t avail_head;
 535
 536         LOG_DEBUG(VHOST_DATA, "(%d) %s\n", dev->vid, __func__);
 537         if (unlikely(!is_valid_virt_queue_idx(queue_id, 0, dev->virt_qp_nb))) {
 538                 RTE_LOG(ERR, VHOST_DATA, "(%d) %s: invalid virtqueue idx %d.\n",
 539                         dev->vid, __func__, queue_id);
 540                 return 0;
 541         }
 542
 543         vq = dev->virtqueue[queue_id];
 544         if (unlikely(vq->enabled == 0))
 545                 return 0;
 546
 547         count = RTE_MIN((uint32_t)MAX_PKT_BURST, count);
 548         if (count == 0)
 549                 return 0;
 550
 551         rte_prefetch0(&vq->avail->ring[vq->last_avail_idx & (vq->size - 1)]);
 552
 553         vq->shadow_used_idx = 0;
 554         avail_head = *((volatile uint16_t *)&vq->avail->idx);
 555         for (pkt_idx = 0; pkt_idx < count; pkt_idx++) {
 556                 uint32_t pkt_len = pkts[pkt_idx]->pkt_len + dev->vhost_hlen;
 557
 558                 if (unlikely(reserve_avail_buf_mergeable(dev, vq,
 559                                                 pkt_len, buf_vec, &num_buffers,
 560                                                 avail_head) < 0)) {
 561                         LOG_DEBUG(VHOST_DATA,
 562                                 "(%d) failed to get enough desc from vring\n",
 563                                 dev->vid);
 564                         vq->shadow_used_idx -= num_buffers;
 565                         break;
 566                 }
 567
 568                 LOG_DEBUG(VHOST_DATA, "(%d) current index %d | end index %d\n",
 569                         dev->vid, vq->last_avail_idx,
 570                         vq->last_avail_idx + num_buffers);
 571
 572                 if (copy_mbuf_to_desc_mergeable(dev, pkts[pkt_idx],
 573                                                 buf_vec, num_buffers) < 0) {
 574                         vq->shadow_used_idx -= num_buffers;
 575                         break;
 576                 }
 577
 578                 vq->last_avail_idx += num_buffers;
 579         }
 580
 581         if (likely(vq->shadow_used_idx)) {
 582                 flush_shadow_used_ring(dev, vq);
 583
 584                 /* flush used->idx update before we read avail->flags. */
 585                 rte_mb();
 586
 587                 /* Kick the guest if necessary. */
 588                 if (!(vq->avail->flags & VRING_AVAIL_F_NO_INTERRUPT)
 589                                 && (vq->callfd >= 0))
 590                         eventfd_write(vq->callfd, (eventfd_t)1);
 591         }
 592
 593         return pkt_idx;
 594 }
 595
 596 uint16_t
 597 rte_vhost_enqueue_burst(int vid, uint16_t queue_id,
 598         struct rte_mbuf **pkts, uint16_t count)
 599 {
 600         struct virtio_net *dev = get_device(vid);
 601
 602         if (!dev)
 603                 return 0;
 604
 605         if (dev->features & (1 << VIRTIO_NET_F_MRG_RXBUF))
 606                 return virtio_dev_merge_rx(dev, queue_id, pkts, count);
 607         else
 608                 return virtio_dev_rx(dev, queue_id, pkts, count);
 609 }
 610
 611 static inline bool
 612 virtio_net_with_host_offload(struct virtio_net *dev)
 613 {
 614         if (dev->features &
 615                         (VIRTIO_NET_F_CSUM | VIRTIO_NET_F_HOST_ECN |
 616                          VIRTIO_NET_F_HOST_TSO4 | VIRTIO_NET_F_HOST_TSO6 |
 617                          VIRTIO_NET_F_HOST_UFO))
 618                 return true;
 619
 620         return false;
 621 }
 622
 623 static void
 624 parse_ethernet(struct rte_mbuf *m, uint16_t *l4_proto, void **l4_hdr)
 625 {
 626         struct ipv4_hdr *ipv4_hdr;
 627         struct ipv6_hdr *ipv6_hdr;
 628         void *l3_hdr = NULL;
 629         struct ether_hdr *eth_hdr;
 630         uint16_t ethertype;
 631
 632         eth_hdr = rte_pktmbuf_mtod(m, struct ether_hdr *);
 633
 634         m->l2_len = sizeof(struct ether_hdr);
 635         ethertype = rte_be_to_cpu_16(eth_hdr->ether_type);
 636
 637         if (ethertype == ETHER_TYPE_VLAN) {
 638                 struct vlan_hdr *vlan_hdr = (struct vlan_hdr *)(eth_hdr + 1);
 639
 640                 m->l2_len += sizeof(struct vlan_hdr);
 641                 ethertype = rte_be_to_cpu_16(vlan_hdr->eth_proto);
 642         }
 643
 644         l3_hdr = (char *)eth_hdr + m->l2_len;
 645
 646         switch (ethertype) {
 647         case ETHER_TYPE_IPv4:
 648                 ipv4_hdr = (struct ipv4_hdr *)l3_hdr;
 649                 *l4_proto = ipv4_hdr->next_proto_id;
 650                 m->l3_len = (ipv4_hdr->version_ihl & 0x0f) * 4;
 651                 *l4_hdr = (char *)l3_hdr + m->l3_len;
 652                 m->ol_flags |= PKT_TX_IPV4;
 653                 break;
 654         case ETHER_TYPE_IPv6:
 655                 ipv6_hdr = (struct ipv6_hdr *)l3_hdr;
 656                 *l4_proto = ipv6_hdr->proto;
 657                 m->l3_len = sizeof(struct ipv6_hdr);
 658                 *l4_hdr = (char *)l3_hdr + m->l3_len;
 659                 m->ol_flags |= PKT_TX_IPV6;
 660                 break;
 661         default:
 662                 m->l3_len = 0;
 663                 *l4_proto = 0;
 664                 break;
 665         }
 666 }
 667
 668 static inline void __attribute__((always_inline))
 669 vhost_dequeue_offload(struct virtio_net_hdr *hdr, struct rte_mbuf *m)
 670 {
 671         uint16_t l4_proto = 0;
 672         void *l4_hdr = NULL;
 673         struct tcp_hdr *tcp_hdr = NULL;
 674
 675         if (hdr->flags == 0 && hdr->gso_type == VIRTIO_NET_HDR_GSO_NONE)
 676                 return;
 677
 678         parse_ethernet(m, &l4_proto, &l4_hdr);
 679         if (hdr->flags == VIRTIO_NET_HDR_F_NEEDS_CSUM) {
 680                 if (hdr->csum_start == (m->l2_len + m->l3_len)) {
 681                         switch (hdr->csum_offset) {
 682                         case (offsetof(struct tcp_hdr, cksum)):
 683                                 if (l4_proto == IPPROTO_TCP)
 684                                         m->ol_flags |= PKT_TX_TCP_CKSUM;
 685                                 break;
 686                         case (offsetof(struct udp_hdr, dgram_cksum)):
 687                                 if (l4_proto == IPPROTO_UDP)
 688                                         m->ol_flags |= PKT_TX_UDP_CKSUM;
 689                                 break;
 690                         case (offsetof(struct sctp_hdr, cksum)):
 691                                 if (l4_proto == IPPROTO_SCTP)
 692                                         m->ol_flags |= PKT_TX_SCTP_CKSUM;
 693                                 break;
 694                         default:
 695                                 break;
 696                         }
 697                 }
 698         }
 699
 700         if (hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) {
 701                 switch (hdr->gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
 702                 case VIRTIO_NET_HDR_GSO_TCPV4:
 703                 case VIRTIO_NET_HDR_GSO_TCPV6:
 704                         tcp_hdr = (struct tcp_hdr *)l4_hdr;
 705                         m->ol_flags |= PKT_TX_TCP_SEG;
 706                         m->tso_segsz = hdr->gso_size;
 707                         m->l4_len = (tcp_hdr->data_off & 0xf0) >> 2;
 708                         break;
 709                 default:
 710                         RTE_LOG(WARNING, VHOST_DATA,
 711                                 "unsupported gso type %u.\n", hdr->gso_type);
 712                         break;
 713                 }
 714         }
 715 }
 716
 717 #define RARP_PKT_SIZE   64
 718
 719 static int
 720 make_rarp_packet(struct rte_mbuf *rarp_mbuf, const struct ether_addr *mac)
 721 {
 722         struct ether_hdr *eth_hdr;
 723         struct arp_hdr  *rarp;
 724
 725         if (rarp_mbuf->buf_len < 64) {
 726                 RTE_LOG(WARNING, VHOST_DATA,
 727                         "failed to make RARP; mbuf size too small %u (< %d)\n",
 728                         rarp_mbuf->buf_len, RARP_PKT_SIZE);
 729                 return -1;
 730         }
 731
 732         /* Ethernet header. */
 733         eth_hdr = rte_pktmbuf_mtod_offset(rarp_mbuf, struct ether_hdr *, 0);
 734         memset(eth_hdr->d_addr.addr_bytes, 0xff, ETHER_ADDR_LEN);
 735         ether_addr_copy(mac, &eth_hdr->s_addr);
 736         eth_hdr->ether_type = htons(ETHER_TYPE_RARP);
 737
 738         /* RARP header. */
 739         rarp = (struct arp_hdr *)(eth_hdr + 1);
 740         rarp->arp_hrd = htons(ARP_HRD_ETHER);
 741         rarp->arp_pro = htons(ETHER_TYPE_IPv4);
 742         rarp->arp_hln = ETHER_ADDR_LEN;
 743         rarp->arp_pln = 4;
 744         rarp->arp_op  = htons(ARP_OP_REVREQUEST);
 745
 746         ether_addr_copy(mac, &rarp->arp_data.arp_sha);
 747         ether_addr_copy(mac, &rarp->arp_data.arp_tha);
 748         memset(&rarp->arp_data.arp_sip, 0x00, 4);
 749         memset(&rarp->arp_data.arp_tip, 0x00, 4);
 750
 751         rarp_mbuf->pkt_len  = rarp_mbuf->data_len = RARP_PKT_SIZE;
 752
 753         return 0;
 754 }
 755
 756 static inline void __attribute__((always_inline))
 757 put_zmbuf(struct zcopy_mbuf *zmbuf)
 758 {
 759         zmbuf->in_use = 0;
 760 }
 761
 762 static inline int __attribute__((always_inline))
 763 copy_desc_to_mbuf(struct virtio_net *dev, struct vring_desc *descs,
 764                   uint16_t max_desc, struct rte_mbuf *m, uint16_t desc_idx,
 765                   struct rte_mempool *mbuf_pool)
 766 {
 767         struct vring_desc *desc;
 768         uint64_t desc_addr;
 769         uint32_t desc_avail, desc_offset;
 770         uint32_t mbuf_avail, mbuf_offset;
 771         uint32_t cpy_len;
 772         struct rte_mbuf *cur = m, *prev = m;
 773         struct virtio_net_hdr *hdr = NULL;
 774         /* A counter to avoid desc dead loop chain */
 775         uint32_t nr_desc = 1;
 776
 777         desc = &descs[desc_idx];
 778         if (unlikely((desc->len < dev->vhost_hlen)) ||
 779                         (desc->flags & VRING_DESC_F_INDIRECT))
 780                 return -1;
 781
 782         desc_addr = gpa_to_vva(dev, desc->addr);
 783         if (unlikely(!desc_addr))
 784                 return -1;
 785
 786         if (virtio_net_with_host_offload(dev)) {
 787                 hdr = (struct virtio_net_hdr *)((uintptr_t)desc_addr);
 788                 rte_prefetch0(hdr);
 789         }
 790
 791         /*
 792          * A virtio driver normally uses at least 2 desc buffers
 793          * for Tx: the first for storing the header, and others
 794          * for storing the data.
 795          */
 796         if (likely((desc->len == dev->vhost_hlen) &&
 797                    (desc->flags & VRING_DESC_F_NEXT) != 0)) {
 798                 desc = &descs[desc->next];
 799                 if (unlikely(desc->flags & VRING_DESC_F_INDIRECT))
 800                         return -1;
 801
 802                 desc_addr = gpa_to_vva(dev, desc->addr);
 803                 if (unlikely(!desc_addr))
 804                         return -1;
 805
 806                 desc_offset = 0;
 807                 desc_avail  = desc->len;
 808                 nr_desc    += 1;
 809         } else {
 810                 desc_avail  = desc->len - dev->vhost_hlen;
 811                 desc_offset = dev->vhost_hlen;
 812         }
 813
 814         rte_prefetch0((void *)(uintptr_t)(desc_addr + desc_offset));
 815
 816         PRINT_PACKET(dev, (uintptr_t)(desc_addr + desc_offset), desc_avail, 0);
 817
 818         mbuf_offset = 0;
 819         mbuf_avail  = m->buf_len - RTE_PKTMBUF_HEADROOM;
 820         while (1) {
 821                 uint64_t hpa;
 822
 823                 cpy_len = RTE_MIN(desc_avail, mbuf_avail);
 824
 825                 /*
 826                  * A desc buf might across two host physical pages that are
 827                  * not continuous. In such case (gpa_to_hpa returns 0), data
 828                  * will be copied even though zero copy is enabled.
 829                  */
 830                 if (unlikely(dev->dequeue_zero_copy && (hpa = gpa_to_hpa(dev,
 831                                         desc->addr + desc_offset, cpy_len)))) {
 832                         cur->data_len = cpy_len;
 833                         cur->data_off = 0;
 834                         cur->buf_addr = (void *)(uintptr_t)desc_addr;
 835                         cur->buf_physaddr = hpa;
 836
 837                         /*
 838                          * In zero copy mode, one mbuf can only reference data
 839                          * for one or partial of one desc buff.
 840                          */
 841                         mbuf_avail = cpy_len;
 842                 } else {
 843                         rte_memcpy(rte_pktmbuf_mtod_offset(cur, void *,
 844                                                            mbuf_offset),
 845                                 (void *)((uintptr_t)(desc_addr + desc_offset)),
 846                                 cpy_len);
 847                 }
 848
 849                 mbuf_avail  -= cpy_len;
 850                 mbuf_offset += cpy_len;
 851                 desc_avail  -= cpy_len;
 852                 desc_offset += cpy_len;
 853
 854                 /* This desc reaches to its end, get the next one */
 855                 if (desc_avail == 0) {
 856                         if ((desc->flags & VRING_DESC_F_NEXT) == 0)
 857                                 break;
 858
 859                         if (unlikely(desc->next >= max_desc ||
 860                                      ++nr_desc > max_desc))
 861                                 return -1;
 862                         desc = &descs[desc->next];
 863                         if (unlikely(desc->flags & VRING_DESC_F_INDIRECT))
 864                                 return -1;
 865
 866                         desc_addr = gpa_to_vva(dev, desc->addr);
 867                         if (unlikely(!desc_addr))
 868                                 return -1;
 869
 870                         rte_prefetch0((void *)(uintptr_t)desc_addr);
 871
 872                         desc_offset = 0;
 873                         desc_avail  = desc->len;
 874
 875                         PRINT_PACKET(dev, (uintptr_t)desc_addr, desc->len, 0);
 876                 }
 877
 878                 /*
 879                  * This mbuf reaches to its end, get a new one
 880                  * to hold more data.
 881                  */
 882                 if (mbuf_avail == 0) {
 883                         cur = rte_pktmbuf_alloc(mbuf_pool);
 884                         if (unlikely(cur == NULL)) {
 885                                 RTE_LOG(ERR, VHOST_DATA, "Failed to "
 886                                         "allocate memory for mbuf.\n");
 887                                 return -1;
 888                         }
 889
 890                         prev->next = cur;
 891                         prev->data_len = mbuf_offset;
 892                         m->nb_segs += 1;
 893                         m->pkt_len += mbuf_offset;
 894                         prev = cur;
 895
 896                         mbuf_offset = 0;
 897                         mbuf_avail  = cur->buf_len - RTE_PKTMBUF_HEADROOM;
 898                 }
 899         }
 900
 901         prev->data_len = mbuf_offset;
 902         m->pkt_len    += mbuf_offset;
 903
 904         if (hdr)
 905                 vhost_dequeue_offload(hdr, m);
 906
 907         return 0;
 908 }
 909
 910 static inline void __attribute__((always_inline))
 911 update_used_ring(struct virtio_net *dev, struct vhost_virtqueue *vq,
 912                  uint32_t used_idx, uint32_t desc_idx)
 913 {
 914         vq->used->ring[used_idx].id  = desc_idx;
 915         vq->used->ring[used_idx].len = 0;
 916         vhost_log_used_vring(dev, vq,
 917                         offsetof(struct vring_used, ring[used_idx]),
 918                         sizeof(vq->used->ring[used_idx]));
 919 }
 920
 921 static inline void __attribute__((always_inline))
 922 update_used_idx(struct virtio_net *dev, struct vhost_virtqueue *vq,
 923                 uint32_t count)
 924 {
 925         if (unlikely(count == 0))
 926                 return;
 927
 928         rte_smp_wmb();
 929         rte_smp_rmb();
 930
 931         vq->used->idx += count;
 932         vhost_log_used_vring(dev, vq, offsetof(struct vring_used, idx),
 933                         sizeof(vq->used->idx));
 934
 935         /* Kick guest if required. */
 936         if (!(vq->avail->flags & VRING_AVAIL_F_NO_INTERRUPT)
 937                         && (vq->callfd >= 0))
 938                 eventfd_write(vq->callfd, (eventfd_t)1);
 939 }
 940
 941 static inline struct zcopy_mbuf *__attribute__((always_inline))
 942 get_zmbuf(struct vhost_virtqueue *vq)
 943 {
 944         uint16_t i;
 945         uint16_t last;
 946         int tries = 0;
 947
 948         /* search [last_zmbuf_idx, zmbuf_size) */
 949         i = vq->last_zmbuf_idx;
 950         last = vq->zmbuf_size;
 951
 952 again:
 953         for (; i < last; i++) {
 954                 if (vq->zmbufs[i].in_use == 0) {
 955                         vq->last_zmbuf_idx = i + 1;
 956                         vq->zmbufs[i].in_use = 1;
 957                         return &vq->zmbufs[i];
 958                 }
 959         }
 960
 961         tries++;
 962         if (tries == 1) {
 963                 /* search [0, last_zmbuf_idx) */
 964                 i = 0;
 965                 last = vq->last_zmbuf_idx;
 966                 goto again;
 967         }
 968
 969         return NULL;
 970 }
 971
 972 static inline bool __attribute__((always_inline))
 973 mbuf_is_consumed(struct rte_mbuf *m)
 974 {
 975         while (m) {
 976                 if (rte_mbuf_refcnt_read(m) > 1)
 977                         return false;
 978                 m = m->next;
 979         }
 980
 981         return true;
 982 }
 983
 984 uint16_t
 985 rte_vhost_dequeue_burst(int vid, uint16_t queue_id,
 986         struct rte_mempool *mbuf_pool, struct rte_mbuf **pkts, uint16_t count)
 987 {
 988         struct virtio_net *dev;
 989         struct rte_mbuf *rarp_mbuf = NULL;
 990         struct vhost_virtqueue *vq;
 991         uint32_t desc_indexes[MAX_PKT_BURST];
 992         uint32_t used_idx;
 993         uint32_t i = 0;
 994         uint16_t free_entries;
 995         uint16_t avail_idx;
 996
 997         dev = get_device(vid);
 998         if (!dev)
 999                 return 0;
1000
1001         if (unlikely(!is_valid_virt_queue_idx(queue_id, 1, dev->virt_qp_nb))) {
1002                 RTE_LOG(ERR, VHOST_DATA, "(%d) %s: invalid virtqueue idx %d.\n",
1003                         dev->vid, __func__, queue_id);
1004                 return 0;
1005         }
1006
1007         vq = dev->virtqueue[queue_id];
1008         if (unlikely(vq->enabled == 0))
1009                 return 0;
1010
1011         if (unlikely(dev->dequeue_zero_copy)) {
1012                 struct zcopy_mbuf *zmbuf, *next;
1013                 int nr_updated = 0;
1014
1015                 for (zmbuf = TAILQ_FIRST(&vq->zmbuf_list);
1016                      zmbuf != NULL; zmbuf = next) {
1017                         next = TAILQ_NEXT(zmbuf, next);
1018
1019                         if (mbuf_is_consumed(zmbuf->mbuf)) {
1020                                 used_idx = vq->last_used_idx++ & (vq->size - 1);
1021                                 update_used_ring(dev, vq, used_idx,
1022                                                  zmbuf->desc_idx);
1023                                 nr_updated += 1;
1024
1025                                 TAILQ_REMOVE(&vq->zmbuf_list, zmbuf, next);
1026                                 rte_pktmbuf_free(zmbuf->mbuf);
1027                                 put_zmbuf(zmbuf);
1028                                 vq->nr_zmbuf -= 1;
1029                         }
1030                 }
1031
1032                 update_used_idx(dev, vq, nr_updated);
1033         }
1034
1035         /*
1036          * Construct a RARP broadcast packet, and inject it to the "pkts"
1037          * array, to looks like that guest actually send such packet.
1038          *
1039          * Check user_send_rarp() for more information.
1040          */
1041         if (unlikely(rte_atomic16_cmpset((volatile uint16_t *)
1042                                          &dev->broadcast_rarp.cnt, 1, 0))) {
1043                 rarp_mbuf = rte_pktmbuf_alloc(mbuf_pool);
1044                 if (rarp_mbuf == NULL) {
1045                         RTE_LOG(ERR, VHOST_DATA,
1046                                 "Failed to allocate memory for mbuf.\n");
1047                         return 0;
1048                 }
1049
1050                 if (make_rarp_packet(rarp_mbuf, &dev->mac)) {
1051                         rte_pktmbuf_free(rarp_mbuf);
1052                         rarp_mbuf = NULL;
1053                 } else {
1054                         count -= 1;
1055                 }
1056         }
1057
1058         free_entries = *((volatile uint16_t *)&vq->avail->idx) -
1059                         vq->last_avail_idx;
1060         if (free_entries == 0)
1061                 goto out;
1062
1063         LOG_DEBUG(VHOST_DATA, "(%d) %s\n", dev->vid, __func__);
1064
1065         /* Prefetch available and used ring */
1066         avail_idx = vq->last_avail_idx & (vq->size - 1);
1067         used_idx  = vq->last_used_idx  & (vq->size - 1);
1068         rte_prefetch0(&vq->avail->ring[avail_idx]);
1069         rte_prefetch0(&vq->used->ring[used_idx]);
1070
1071         count = RTE_MIN(count, MAX_PKT_BURST);
1072         count = RTE_MIN(count, free_entries);
1073         LOG_DEBUG(VHOST_DATA, "(%d) about to dequeue %u buffers\n",
1074                         dev->vid, count);
1075
1076         /* Retrieve all of the head indexes first to avoid caching issues. */
1077         for (i = 0; i < count; i++) {
1078                 avail_idx = (vq->last_avail_idx + i) & (vq->size - 1);
1079                 used_idx  = (vq->last_used_idx  + i) & (vq->size - 1);
1080                 desc_indexes[i] = vq->avail->ring[avail_idx];
1081
1082                 if (likely(dev->dequeue_zero_copy == 0))
1083                         update_used_ring(dev, vq, used_idx, desc_indexes[i]);
1084         }
1085
1086         /* Prefetch descriptor index. */
1087         rte_prefetch0(&vq->desc[desc_indexes[0]]);
1088         for (i = 0; i < count; i++) {
1089                 struct vring_desc *desc;
1090                 uint16_t sz, idx;
1091                 int err;
1092
1093                 if (likely(i + 1 < count))
1094                         rte_prefetch0(&vq->desc[desc_indexes[i + 1]]);
1095
1096                 if (vq->desc[desc_indexes[i]].flags & VRING_DESC_F_INDIRECT) {
1097                         desc = (struct vring_desc *)(uintptr_t)gpa_to_vva(dev,
1098                                         vq->desc[desc_indexes[i]].addr);
1099                         if (unlikely(!desc))
1100                                 break;
1101
1102                         rte_prefetch0(desc);
1103                         sz = vq->desc[desc_indexes[i]].len / sizeof(*desc);
1104                         idx = 0;
1105                 } else {
1106                         desc = vq->desc;
1107                         sz = vq->size;
1108                         idx = desc_indexes[i];
1109                 }
1110
1111                 pkts[i] = rte_pktmbuf_alloc(mbuf_pool);
1112                 if (unlikely(pkts[i] == NULL)) {
1113                         RTE_LOG(ERR, VHOST_DATA,
1114                                 "Failed to allocate memory for mbuf.\n");
1115                         break;
1116                 }
1117
1118                 err = copy_desc_to_mbuf(dev, desc, sz, pkts[i], idx, mbuf_pool);
1119                 if (unlikely(err)) {
1120                         rte_pktmbuf_free(pkts[i]);
1121                         break;
1122                 }
1123
1124                 if (unlikely(dev->dequeue_zero_copy)) {
1125                         struct zcopy_mbuf *zmbuf;
1126
1127                         zmbuf = get_zmbuf(vq);
1128                         if (!zmbuf) {
1129                                 rte_pktmbuf_free(pkts[i]);
1130                                 break;
1131                         }
1132                         zmbuf->mbuf = pkts[i];
1133                         zmbuf->desc_idx = desc_indexes[i];
1134
1135                         /*
1136                          * Pin lock the mbuf; we will check later to see
1137                          * whether the mbuf is freed (when we are the last
1138                          * user) or not. If that's the case, we then could
1139                          * update the used ring safely.
1140                          */
1141                         rte_mbuf_refcnt_update(pkts[i], 1);
1142
1143                         vq->nr_zmbuf += 1;
1144                         TAILQ_INSERT_TAIL(&vq->zmbuf_list, zmbuf, next);
1145                 }
1146         }
1147         vq->last_avail_idx += i;
1148
1149         if (likely(dev->dequeue_zero_copy == 0)) {
1150                 vq->last_used_idx += i;
1151                 update_used_idx(dev, vq, i);
1152         }
1153
1154 out:
1155         if (unlikely(rarp_mbuf != NULL)) {
1156                 /*
1157                  * Inject it to the head of "pkts" array, so that switch's mac
1158                  * learning table will get updated first.
1159                  */
1160                 memmove(&pkts[1], pkts, i * sizeof(struct rte_mbuf *));
1161                 pkts[0] = rarp_mbuf;
1162                 i += 1;
1163         }
1164
1165         return i;
1166 }