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 vring_desc *descs,
 190                   struct rte_mbuf *m, uint16_t desc_idx, uint32_t size)
 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 = &descs[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 >= size))
 237                                 return -1;
 238
 239                         desc = &descs[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         struct vring_desc *descs;
 280         uint16_t used_idx;
 281         uint32_t i, sz;
 282
 283         LOG_DEBUG(VHOST_DATA, "(%d) %s\n", dev->vid, __func__);
 284         if (unlikely(!is_valid_virt_queue_idx(queue_id, 0, dev->virt_qp_nb))) {
 285                 RTE_LOG(ERR, VHOST_DATA, "(%d) %s: invalid virtqueue idx %d.\n",
 286                         dev->vid, __func__, queue_id);
 287                 return 0;
 288         }
 289
 290         vq = dev->virtqueue[queue_id];
 291         if (unlikely(vq->enabled == 0))
 292                 return 0;
 293
 294         avail_idx = *((volatile uint16_t *)&vq->avail->idx);
 295         start_idx = vq->last_used_idx;
 296         free_entries = avail_idx - start_idx;
 297         count = RTE_MIN(count, free_entries);
 298         count = RTE_MIN(count, (uint32_t)MAX_PKT_BURST);
 299         if (count == 0)
 300                 return 0;
 301
 302         LOG_DEBUG(VHOST_DATA, "(%d) start_idx %d | end_idx %d\n",
 303                 dev->vid, start_idx, start_idx + count);
 304
 305         /* Retrieve all of the desc indexes first to avoid caching issues. */
 306         rte_prefetch0(&vq->avail->ring[start_idx & (vq->size - 1)]);
 307         for (i = 0; i < count; i++) {
 308                 used_idx = (start_idx + i) & (vq->size - 1);
 309                 desc_indexes[i] = vq->avail->ring[used_idx];
 310                 vq->used->ring[used_idx].id = desc_indexes[i];
 311                 vq->used->ring[used_idx].len = pkts[i]->pkt_len +
 312                                                dev->vhost_hlen;
 313                 vhost_log_used_vring(dev, vq,
 314                         offsetof(struct vring_used, ring[used_idx]),
 315                         sizeof(vq->used->ring[used_idx]));
 316         }
 317
 318         rte_prefetch0(&vq->desc[desc_indexes[0]]);
 319         for (i = 0; i < count; i++) {
 320                 uint16_t desc_idx = desc_indexes[i];
 321                 int err;
 322
 323                 if (vq->desc[desc_idx].flags & VRING_DESC_F_INDIRECT) {
 324                         descs = (struct vring_desc *)(uintptr_t)gpa_to_vva(dev,
 325                                         vq->desc[desc_idx].addr);
 326                         if (unlikely(!descs)) {
 327                                 count = i;
 328                                 break;
 329                         }
 330
 331                         desc_idx = 0;
 332                         sz = vq->desc[desc_idx].len / sizeof(*descs);
 333                 } else {
 334                         descs = vq->desc;
 335                         sz = vq->size;
 336                 }
 337
 338                 err = copy_mbuf_to_desc(dev, descs, pkts[i], desc_idx, sz);
 339                 if (unlikely(err)) {
 340                         used_idx = (start_idx + i) & (vq->size - 1);
 341                         vq->used->ring[used_idx].len = dev->vhost_hlen;
 342                         vhost_log_used_vring(dev, vq,
 343                                 offsetof(struct vring_used, ring[used_idx]),
 344                                 sizeof(vq->used->ring[used_idx]));
 345                 }
 346
 347                 if (i + 1 < count)
 348                         rte_prefetch0(&vq->desc[desc_indexes[i+1]]);
 349         }
 350
 351         rte_smp_wmb();
 352
 353         *(volatile uint16_t *)&vq->used->idx += count;
 354         vq->last_used_idx += count;
 355         vhost_log_used_vring(dev, vq,
 356                 offsetof(struct vring_used, idx),
 357                 sizeof(vq->used->idx));
 358
 359         /* flush used->idx update before we read avail->flags. */
 360         rte_mb();
 361
 362         /* Kick the guest if necessary. */
 363         if (!(vq->avail->flags & VRING_AVAIL_F_NO_INTERRUPT)
 364                         && (vq->callfd >= 0))
 365                 eventfd_write(vq->callfd, (eventfd_t)1);
 366         return count;
 367 }
 368
 369 static inline int __attribute__((always_inline))
 370 fill_vec_buf(struct virtio_net *dev, struct vhost_virtqueue *vq,
 371                          uint32_t avail_idx, uint32_t *vec_idx,
 372                          struct buf_vector *buf_vec, uint16_t *desc_chain_head,
 373                          uint16_t *desc_chain_len)
 374 {
 375         uint16_t idx = vq->avail->ring[avail_idx & (vq->size - 1)];
 376         uint32_t vec_id = *vec_idx;
 377         uint32_t len    = 0;
 378         struct vring_desc *descs = vq->desc;
 379
 380         *desc_chain_head = idx;
 381
 382         if (vq->desc[idx].flags & VRING_DESC_F_INDIRECT) {
 383                 descs = (struct vring_desc *)(uintptr_t)
 384                                         gpa_to_vva(dev, vq->desc[idx].addr);
 385                 if (unlikely(!descs))
 386                         return -1;
 387
 388                 idx = 0;
 389         }
 390
 391         while (1) {
 392                 if (unlikely(vec_id >= BUF_VECTOR_MAX || idx >= vq->size))
 393                         return -1;
 394
 395                 len += descs[idx].len;
 396                 buf_vec[vec_id].buf_addr = descs[idx].addr;
 397                 buf_vec[vec_id].buf_len  = descs[idx].len;
 398                 buf_vec[vec_id].desc_idx = idx;
 399                 vec_id++;
 400
 401                 if ((descs[idx].flags & VRING_DESC_F_NEXT) == 0)
 402                         break;
 403
 404                 idx = descs[idx].next;
 405         }
 406
 407         *desc_chain_len = len;
 408         *vec_idx = vec_id;
 409
 410         return 0;
 411 }
 412
 413 /*
 414  * Returns -1 on fail, 0 on success
 415  */
 416 static inline int
 417 reserve_avail_buf_mergeable(struct virtio_net *dev, struct vhost_virtqueue *vq,
 418                                 uint32_t size, struct buf_vector *buf_vec,
 419                                 uint16_t *num_buffers, uint16_t avail_head)
 420 {
 421         uint16_t cur_idx;
 422         uint32_t vec_idx = 0;
 423         uint16_t tries = 0;
 424
 425         uint16_t head_idx = 0;
 426         uint16_t len = 0;
 427
 428         *num_buffers = 0;
 429         cur_idx  = vq->last_avail_idx;
 430
 431         while (size > 0) {
 432                 if (unlikely(cur_idx == avail_head))
 433                         return -1;
 434
 435                 if (unlikely(fill_vec_buf(dev, vq, cur_idx, &vec_idx, buf_vec,
 436                                                 &head_idx, &len) < 0))
 437                         return -1;
 438                 len = RTE_MIN(len, size);
 439                 update_shadow_used_ring(vq, head_idx, len);
 440                 size -= len;
 441
 442                 cur_idx++;
 443                 tries++;
 444                 *num_buffers += 1;
 445
 446                 /*
 447                  * if we tried all available ring items, and still
 448                  * can't get enough buf, it means something abnormal
 449                  * happened.
 450                  */
 451                 if (unlikely(tries >= vq->size))
 452                         return -1;
 453         }
 454
 455         return 0;
 456 }
 457
 458 static inline int __attribute__((always_inline))
 459 copy_mbuf_to_desc_mergeable(struct virtio_net *dev, struct rte_mbuf *m,
 460                             struct buf_vector *buf_vec, uint16_t num_buffers)
 461 {
 462         struct virtio_net_hdr_mrg_rxbuf virtio_hdr = {{0, 0, 0, 0, 0, 0}, 0};
 463         uint32_t vec_idx = 0;
 464         uint64_t desc_addr;
 465         uint32_t mbuf_offset, mbuf_avail;
 466         uint32_t desc_offset, desc_avail;
 467         uint32_t cpy_len;
 468         uint64_t hdr_addr, hdr_phys_addr;
 469         struct rte_mbuf *hdr_mbuf;
 470
 471         if (unlikely(m == NULL))
 472                 return -1;
 473
 474         desc_addr = gpa_to_vva(dev, buf_vec[vec_idx].buf_addr);
 475         if (buf_vec[vec_idx].buf_len < dev->vhost_hlen || !desc_addr)
 476                 return -1;
 477
 478         hdr_mbuf = m;
 479         hdr_addr = desc_addr;
 480         hdr_phys_addr = buf_vec[vec_idx].buf_addr;
 481         rte_prefetch0((void *)(uintptr_t)hdr_addr);
 482
 483         virtio_hdr.num_buffers = num_buffers;
 484         LOG_DEBUG(VHOST_DATA, "(%d) RX: num merge buffers %d\n",
 485                 dev->vid, num_buffers);
 486
 487         desc_avail  = buf_vec[vec_idx].buf_len - dev->vhost_hlen;
 488         desc_offset = dev->vhost_hlen;
 489
 490         mbuf_avail  = rte_pktmbuf_data_len(m);
 491         mbuf_offset = 0;
 492         while (mbuf_avail != 0 || m->next != NULL) {
 493                 /* done with current desc buf, get the next one */
 494                 if (desc_avail == 0) {
 495                         vec_idx++;
 496                         desc_addr = gpa_to_vva(dev, buf_vec[vec_idx].buf_addr);
 497                         if (unlikely(!desc_addr))
 498                                 return -1;
 499
 500                         /* Prefetch buffer address. */
 501                         rte_prefetch0((void *)(uintptr_t)desc_addr);
 502                         desc_offset = 0;
 503                         desc_avail  = buf_vec[vec_idx].buf_len;
 504                 }
 505
 506                 /* done with current mbuf, get the next one */
 507                 if (mbuf_avail == 0) {
 508                         m = m->next;
 509
 510                         mbuf_offset = 0;
 511                         mbuf_avail  = rte_pktmbuf_data_len(m);
 512                 }
 513
 514                 if (hdr_addr) {
 515                         virtio_enqueue_offload(hdr_mbuf, &virtio_hdr.hdr);
 516                         copy_virtio_net_hdr(dev, hdr_addr, virtio_hdr);
 517                         vhost_log_write(dev, hdr_phys_addr, dev->vhost_hlen);
 518                         PRINT_PACKET(dev, (uintptr_t)hdr_addr,
 519                                      dev->vhost_hlen, 0);
 520
 521                         hdr_addr = 0;
 522                 }
 523
 524                 cpy_len = RTE_MIN(desc_avail, mbuf_avail);
 525                 rte_memcpy((void *)((uintptr_t)(desc_addr + desc_offset)),
 526                         rte_pktmbuf_mtod_offset(m, void *, mbuf_offset),
 527                         cpy_len);
 528                 vhost_log_write(dev, buf_vec[vec_idx].buf_addr + desc_offset,
 529                         cpy_len);
 530                 PRINT_PACKET(dev, (uintptr_t)(desc_addr + desc_offset),
 531                         cpy_len, 0);
 532
 533                 mbuf_avail  -= cpy_len;
 534                 mbuf_offset += cpy_len;
 535                 desc_avail  -= cpy_len;
 536                 desc_offset += cpy_len;
 537         }
 538
 539         return 0;
 540 }
 541
 542 static inline uint32_t __attribute__((always_inline))
 543 virtio_dev_merge_rx(struct virtio_net *dev, uint16_t queue_id,
 544         struct rte_mbuf **pkts, uint32_t count)
 545 {
 546         struct vhost_virtqueue *vq;
 547         uint32_t pkt_idx = 0;
 548         uint16_t num_buffers;
 549         struct buf_vector buf_vec[BUF_VECTOR_MAX];
 550         uint16_t avail_head;
 551
 552         LOG_DEBUG(VHOST_DATA, "(%d) %s\n", dev->vid, __func__);
 553         if (unlikely(!is_valid_virt_queue_idx(queue_id, 0, dev->virt_qp_nb))) {
 554                 RTE_LOG(ERR, VHOST_DATA, "(%d) %s: invalid virtqueue idx %d.\n",
 555                         dev->vid, __func__, queue_id);
 556                 return 0;
 557         }
 558
 559         vq = dev->virtqueue[queue_id];
 560         if (unlikely(vq->enabled == 0))
 561                 return 0;
 562
 563         count = RTE_MIN((uint32_t)MAX_PKT_BURST, count);
 564         if (count == 0)
 565                 return 0;
 566
 567         rte_prefetch0(&vq->avail->ring[vq->last_avail_idx & (vq->size - 1)]);
 568
 569         vq->shadow_used_idx = 0;
 570         avail_head = *((volatile uint16_t *)&vq->avail->idx);
 571         for (pkt_idx = 0; pkt_idx < count; pkt_idx++) {
 572                 uint32_t pkt_len = pkts[pkt_idx]->pkt_len + dev->vhost_hlen;
 573
 574                 if (unlikely(reserve_avail_buf_mergeable(dev, vq,
 575                                                 pkt_len, buf_vec, &num_buffers,
 576                                                 avail_head) < 0)) {
 577                         LOG_DEBUG(VHOST_DATA,
 578                                 "(%d) failed to get enough desc from vring\n",
 579                                 dev->vid);
 580                         vq->shadow_used_idx -= num_buffers;
 581                         break;
 582                 }
 583
 584                 LOG_DEBUG(VHOST_DATA, "(%d) current index %d | end index %d\n",
 585                         dev->vid, vq->last_avail_idx,
 586                         vq->last_avail_idx + num_buffers);
 587
 588                 if (copy_mbuf_to_desc_mergeable(dev, pkts[pkt_idx],
 589                                                 buf_vec, num_buffers) < 0) {
 590                         vq->shadow_used_idx -= num_buffers;
 591                         break;
 592                 }
 593
 594                 vq->last_avail_idx += num_buffers;
 595         }
 596
 597         if (likely(vq->shadow_used_idx)) {
 598                 flush_shadow_used_ring(dev, vq);
 599
 600                 /* flush used->idx update before we read avail->flags. */
 601                 rte_mb();
 602
 603                 /* Kick the guest if necessary. */
 604                 if (!(vq->avail->flags & VRING_AVAIL_F_NO_INTERRUPT)
 605                                 && (vq->callfd >= 0))
 606                         eventfd_write(vq->callfd, (eventfd_t)1);
 607         }
 608
 609         return pkt_idx;
 610 }
 611
 612 uint16_t
 613 rte_vhost_enqueue_burst(int vid, uint16_t queue_id,
 614         struct rte_mbuf **pkts, uint16_t count)
 615 {
 616         struct virtio_net *dev = get_device(vid);
 617
 618         if (!dev)
 619                 return 0;
 620
 621         if (dev->features & (1 << VIRTIO_NET_F_MRG_RXBUF))
 622                 return virtio_dev_merge_rx(dev, queue_id, pkts, count);
 623         else
 624                 return virtio_dev_rx(dev, queue_id, pkts, count);
 625 }
 626
 627 static inline bool
 628 virtio_net_with_host_offload(struct virtio_net *dev)
 629 {
 630         if (dev->features &
 631                         (VIRTIO_NET_F_CSUM | VIRTIO_NET_F_HOST_ECN |
 632                          VIRTIO_NET_F_HOST_TSO4 | VIRTIO_NET_F_HOST_TSO6 |
 633                          VIRTIO_NET_F_HOST_UFO))
 634                 return true;
 635
 636         return false;
 637 }
 638
 639 static void
 640 parse_ethernet(struct rte_mbuf *m, uint16_t *l4_proto, void **l4_hdr)
 641 {
 642         struct ipv4_hdr *ipv4_hdr;
 643         struct ipv6_hdr *ipv6_hdr;
 644         void *l3_hdr = NULL;
 645         struct ether_hdr *eth_hdr;
 646         uint16_t ethertype;
 647
 648         eth_hdr = rte_pktmbuf_mtod(m, struct ether_hdr *);
 649
 650         m->l2_len = sizeof(struct ether_hdr);
 651         ethertype = rte_be_to_cpu_16(eth_hdr->ether_type);
 652
 653         if (ethertype == ETHER_TYPE_VLAN) {
 654                 struct vlan_hdr *vlan_hdr = (struct vlan_hdr *)(eth_hdr + 1);
 655
 656                 m->l2_len += sizeof(struct vlan_hdr);
 657                 ethertype = rte_be_to_cpu_16(vlan_hdr->eth_proto);
 658         }
 659
 660         l3_hdr = (char *)eth_hdr + m->l2_len;
 661
 662         switch (ethertype) {
 663         case ETHER_TYPE_IPv4:
 664                 ipv4_hdr = (struct ipv4_hdr *)l3_hdr;
 665                 *l4_proto = ipv4_hdr->next_proto_id;
 666                 m->l3_len = (ipv4_hdr->version_ihl & 0x0f) * 4;
 667                 *l4_hdr = (char *)l3_hdr + m->l3_len;
 668                 m->ol_flags |= PKT_TX_IPV4;
 669                 break;
 670         case ETHER_TYPE_IPv6:
 671                 ipv6_hdr = (struct ipv6_hdr *)l3_hdr;
 672                 *l4_proto = ipv6_hdr->proto;
 673                 m->l3_len = sizeof(struct ipv6_hdr);
 674                 *l4_hdr = (char *)l3_hdr + m->l3_len;
 675                 m->ol_flags |= PKT_TX_IPV6;
 676                 break;
 677         default:
 678                 m->l3_len = 0;
 679                 *l4_proto = 0;
 680                 break;
 681         }
 682 }
 683
 684 static inline void __attribute__((always_inline))
 685 vhost_dequeue_offload(struct virtio_net_hdr *hdr, struct rte_mbuf *m)
 686 {
 687         uint16_t l4_proto = 0;
 688         void *l4_hdr = NULL;
 689         struct tcp_hdr *tcp_hdr = NULL;
 690
 691         if (hdr->flags == 0 && hdr->gso_type == VIRTIO_NET_HDR_GSO_NONE)
 692                 return;
 693
 694         parse_ethernet(m, &l4_proto, &l4_hdr);
 695         if (hdr->flags == VIRTIO_NET_HDR_F_NEEDS_CSUM) {
 696                 if (hdr->csum_start == (m->l2_len + m->l3_len)) {
 697                         switch (hdr->csum_offset) {
 698                         case (offsetof(struct tcp_hdr, cksum)):
 699                                 if (l4_proto == IPPROTO_TCP)
 700                                         m->ol_flags |= PKT_TX_TCP_CKSUM;
 701                                 break;
 702                         case (offsetof(struct udp_hdr, dgram_cksum)):
 703                                 if (l4_proto == IPPROTO_UDP)
 704                                         m->ol_flags |= PKT_TX_UDP_CKSUM;
 705                                 break;
 706                         case (offsetof(struct sctp_hdr, cksum)):
 707                                 if (l4_proto == IPPROTO_SCTP)
 708                                         m->ol_flags |= PKT_TX_SCTP_CKSUM;
 709                                 break;
 710                         default:
 711                                 break;
 712                         }
 713                 }
 714         }
 715
 716         if (hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) {
 717                 switch (hdr->gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
 718                 case VIRTIO_NET_HDR_GSO_TCPV4:
 719                 case VIRTIO_NET_HDR_GSO_TCPV6:
 720                         tcp_hdr = (struct tcp_hdr *)l4_hdr;
 721                         m->ol_flags |= PKT_TX_TCP_SEG;
 722                         m->tso_segsz = hdr->gso_size;
 723                         m->l4_len = (tcp_hdr->data_off & 0xf0) >> 2;
 724                         break;
 725                 default:
 726                         RTE_LOG(WARNING, VHOST_DATA,
 727                                 "unsupported gso type %u.\n", hdr->gso_type);
 728                         break;
 729                 }
 730         }
 731 }
 732
 733 #define RARP_PKT_SIZE   64
 734
 735 static int
 736 make_rarp_packet(struct rte_mbuf *rarp_mbuf, const struct ether_addr *mac)
 737 {
 738         struct ether_hdr *eth_hdr;
 739         struct arp_hdr  *rarp;
 740
 741         if (rarp_mbuf->buf_len < 64) {
 742                 RTE_LOG(WARNING, VHOST_DATA,
 743                         "failed to make RARP; mbuf size too small %u (< %d)\n",
 744                         rarp_mbuf->buf_len, RARP_PKT_SIZE);
 745                 return -1;
 746         }
 747
 748         /* Ethernet header. */
 749         eth_hdr = rte_pktmbuf_mtod_offset(rarp_mbuf, struct ether_hdr *, 0);
 750         memset(eth_hdr->d_addr.addr_bytes, 0xff, ETHER_ADDR_LEN);
 751         ether_addr_copy(mac, &eth_hdr->s_addr);
 752         eth_hdr->ether_type = htons(ETHER_TYPE_RARP);
 753
 754         /* RARP header. */
 755         rarp = (struct arp_hdr *)(eth_hdr + 1);
 756         rarp->arp_hrd = htons(ARP_HRD_ETHER);
 757         rarp->arp_pro = htons(ETHER_TYPE_IPv4);
 758         rarp->arp_hln = ETHER_ADDR_LEN;
 759         rarp->arp_pln = 4;
 760         rarp->arp_op  = htons(ARP_OP_REVREQUEST);
 761
 762         ether_addr_copy(mac, &rarp->arp_data.arp_sha);
 763         ether_addr_copy(mac, &rarp->arp_data.arp_tha);
 764         memset(&rarp->arp_data.arp_sip, 0x00, 4);
 765         memset(&rarp->arp_data.arp_tip, 0x00, 4);
 766
 767         rarp_mbuf->pkt_len  = rarp_mbuf->data_len = RARP_PKT_SIZE;
 768
 769         return 0;
 770 }
 771
 772 static inline void __attribute__((always_inline))
 773 put_zmbuf(struct zcopy_mbuf *zmbuf)
 774 {
 775         zmbuf->in_use = 0;
 776 }
 777
 778 static inline int __attribute__((always_inline))
 779 copy_desc_to_mbuf(struct virtio_net *dev, struct vring_desc *descs,
 780                   uint16_t max_desc, struct rte_mbuf *m, uint16_t desc_idx,
 781                   struct rte_mempool *mbuf_pool)
 782 {
 783         struct vring_desc *desc;
 784         uint64_t desc_addr;
 785         uint32_t desc_avail, desc_offset;
 786         uint32_t mbuf_avail, mbuf_offset;
 787         uint32_t cpy_len;
 788         struct rte_mbuf *cur = m, *prev = m;
 789         struct virtio_net_hdr *hdr = NULL;
 790         /* A counter to avoid desc dead loop chain */
 791         uint32_t nr_desc = 1;
 792
 793         desc = &descs[desc_idx];
 794         if (unlikely((desc->len < dev->vhost_hlen)) ||
 795                         (desc->flags & VRING_DESC_F_INDIRECT))
 796                 return -1;
 797
 798         desc_addr = gpa_to_vva(dev, desc->addr);
 799         if (unlikely(!desc_addr))
 800                 return -1;
 801
 802         if (virtio_net_with_host_offload(dev)) {
 803                 hdr = (struct virtio_net_hdr *)((uintptr_t)desc_addr);
 804                 rte_prefetch0(hdr);
 805         }
 806
 807         /*
 808          * A virtio driver normally uses at least 2 desc buffers
 809          * for Tx: the first for storing the header, and others
 810          * for storing the data.
 811          */
 812         if (likely((desc->len == dev->vhost_hlen) &&
 813                    (desc->flags & VRING_DESC_F_NEXT) != 0)) {
 814                 desc = &descs[desc->next];
 815                 if (unlikely(desc->flags & VRING_DESC_F_INDIRECT))
 816                         return -1;
 817
 818                 desc_addr = gpa_to_vva(dev, desc->addr);
 819                 if (unlikely(!desc_addr))
 820                         return -1;
 821
 822                 desc_offset = 0;
 823                 desc_avail  = desc->len;
 824                 nr_desc    += 1;
 825         } else {
 826                 desc_avail  = desc->len - dev->vhost_hlen;
 827                 desc_offset = dev->vhost_hlen;
 828         }
 829
 830         rte_prefetch0((void *)(uintptr_t)(desc_addr + desc_offset));
 831
 832         PRINT_PACKET(dev, (uintptr_t)(desc_addr + desc_offset), desc_avail, 0);
 833
 834         mbuf_offset = 0;
 835         mbuf_avail  = m->buf_len - RTE_PKTMBUF_HEADROOM;
 836         while (1) {
 837                 uint64_t hpa;
 838
 839                 cpy_len = RTE_MIN(desc_avail, mbuf_avail);
 840
 841                 /*
 842                  * A desc buf might across two host physical pages that are
 843                  * not continuous. In such case (gpa_to_hpa returns 0), data
 844                  * will be copied even though zero copy is enabled.
 845                  */
 846                 if (unlikely(dev->dequeue_zero_copy && (hpa = gpa_to_hpa(dev,
 847                                         desc->addr + desc_offset, cpy_len)))) {
 848                         cur->data_len = cpy_len;
 849                         cur->data_off = 0;
 850                         cur->buf_addr = (void *)(uintptr_t)desc_addr;
 851                         cur->buf_physaddr = hpa;
 852
 853                         /*
 854                          * In zero copy mode, one mbuf can only reference data
 855                          * for one or partial of one desc buff.
 856                          */
 857                         mbuf_avail = cpy_len;
 858                 } else {
 859                         rte_memcpy(rte_pktmbuf_mtod_offset(cur, void *,
 860                                                            mbuf_offset),
 861                                 (void *)((uintptr_t)(desc_addr + desc_offset)),
 862                                 cpy_len);
 863                 }
 864
 865                 mbuf_avail  -= cpy_len;
 866                 mbuf_offset += cpy_len;
 867                 desc_avail  -= cpy_len;
 868                 desc_offset += cpy_len;
 869
 870                 /* This desc reaches to its end, get the next one */
 871                 if (desc_avail == 0) {
 872                         if ((desc->flags & VRING_DESC_F_NEXT) == 0)
 873                                 break;
 874
 875                         if (unlikely(desc->next >= max_desc ||
 876                                      ++nr_desc > max_desc))
 877                                 return -1;
 878                         desc = &descs[desc->next];
 879                         if (unlikely(desc->flags & VRING_DESC_F_INDIRECT))
 880                                 return -1;
 881
 882                         desc_addr = gpa_to_vva(dev, desc->addr);
 883                         if (unlikely(!desc_addr))
 884                                 return -1;
 885
 886                         rte_prefetch0((void *)(uintptr_t)desc_addr);
 887
 888                         desc_offset = 0;
 889                         desc_avail  = desc->len;
 890
 891                         PRINT_PACKET(dev, (uintptr_t)desc_addr, desc->len, 0);
 892                 }
 893
 894                 /*
 895                  * This mbuf reaches to its end, get a new one
 896                  * to hold more data.
 897                  */
 898                 if (mbuf_avail == 0) {
 899                         cur = rte_pktmbuf_alloc(mbuf_pool);
 900                         if (unlikely(cur == NULL)) {
 901                                 RTE_LOG(ERR, VHOST_DATA, "Failed to "
 902                                         "allocate memory for mbuf.\n");
 903                                 return -1;
 904                         }
 905
 906                         prev->next = cur;
 907                         prev->data_len = mbuf_offset;
 908                         m->nb_segs += 1;
 909                         m->pkt_len += mbuf_offset;
 910                         prev = cur;
 911
 912                         mbuf_offset = 0;
 913                         mbuf_avail  = cur->buf_len - RTE_PKTMBUF_HEADROOM;
 914                 }
 915         }
 916
 917         prev->data_len = mbuf_offset;
 918         m->pkt_len    += mbuf_offset;
 919
 920         if (hdr)
 921                 vhost_dequeue_offload(hdr, m);
 922
 923         return 0;
 924 }
 925
 926 static inline void __attribute__((always_inline))
 927 update_used_ring(struct virtio_net *dev, struct vhost_virtqueue *vq,
 928                  uint32_t used_idx, uint32_t desc_idx)
 929 {
 930         vq->used->ring[used_idx].id  = desc_idx;
 931         vq->used->ring[used_idx].len = 0;
 932         vhost_log_used_vring(dev, vq,
 933                         offsetof(struct vring_used, ring[used_idx]),
 934                         sizeof(vq->used->ring[used_idx]));
 935 }
 936
 937 static inline void __attribute__((always_inline))
 938 update_used_idx(struct virtio_net *dev, struct vhost_virtqueue *vq,
 939                 uint32_t count)
 940 {
 941         if (unlikely(count == 0))
 942                 return;
 943
 944         rte_smp_wmb();
 945         rte_smp_rmb();
 946
 947         vq->used->idx += count;
 948         vhost_log_used_vring(dev, vq, offsetof(struct vring_used, idx),
 949                         sizeof(vq->used->idx));
 950
 951         /* Kick guest if required. */
 952         if (!(vq->avail->flags & VRING_AVAIL_F_NO_INTERRUPT)
 953                         && (vq->callfd >= 0))
 954                 eventfd_write(vq->callfd, (eventfd_t)1);
 955 }
 956
 957 static inline struct zcopy_mbuf *__attribute__((always_inline))
 958 get_zmbuf(struct vhost_virtqueue *vq)
 959 {
 960         uint16_t i;
 961         uint16_t last;
 962         int tries = 0;
 963
 964         /* search [last_zmbuf_idx, zmbuf_size) */
 965         i = vq->last_zmbuf_idx;
 966         last = vq->zmbuf_size;
 967
 968 again:
 969         for (; i < last; i++) {
 970                 if (vq->zmbufs[i].in_use == 0) {
 971                         vq->last_zmbuf_idx = i + 1;
 972                         vq->zmbufs[i].in_use = 1;
 973                         return &vq->zmbufs[i];
 974                 }
 975         }
 976
 977         tries++;
 978         if (tries == 1) {
 979                 /* search [0, last_zmbuf_idx) */
 980                 i = 0;
 981                 last = vq->last_zmbuf_idx;
 982                 goto again;
 983         }
 984
 985         return NULL;
 986 }
 987
 988 static inline bool __attribute__((always_inline))
 989 mbuf_is_consumed(struct rte_mbuf *m)
 990 {
 991         while (m) {
 992                 if (rte_mbuf_refcnt_read(m) > 1)
 993                         return false;
 994                 m = m->next;
 995         }
 996
 997         return true;
 998 }
 999
1000 uint16_t
1001 rte_vhost_dequeue_burst(int vid, uint16_t queue_id,
1002         struct rte_mempool *mbuf_pool, struct rte_mbuf **pkts, uint16_t count)
1003 {
1004         struct virtio_net *dev;
1005         struct rte_mbuf *rarp_mbuf = NULL;
1006         struct vhost_virtqueue *vq;
1007         uint32_t desc_indexes[MAX_PKT_BURST];
1008         uint32_t used_idx;
1009         uint32_t i = 0;
1010         uint16_t free_entries;
1011         uint16_t avail_idx;
1012
1013         dev = get_device(vid);
1014         if (!dev)
1015                 return 0;
1016
1017         if (unlikely(!is_valid_virt_queue_idx(queue_id, 1, dev->virt_qp_nb))) {
1018                 RTE_LOG(ERR, VHOST_DATA, "(%d) %s: invalid virtqueue idx %d.\n",
1019                         dev->vid, __func__, queue_id);
1020                 return 0;
1021         }
1022
1023         vq = dev->virtqueue[queue_id];
1024         if (unlikely(vq->enabled == 0))
1025                 return 0;
1026
1027         if (unlikely(dev->dequeue_zero_copy)) {
1028                 struct zcopy_mbuf *zmbuf, *next;
1029                 int nr_updated = 0;
1030
1031                 for (zmbuf = TAILQ_FIRST(&vq->zmbuf_list);
1032                      zmbuf != NULL; zmbuf = next) {
1033                         next = TAILQ_NEXT(zmbuf, next);
1034
1035                         if (mbuf_is_consumed(zmbuf->mbuf)) {
1036                                 used_idx = vq->last_used_idx++ & (vq->size - 1);
1037                                 update_used_ring(dev, vq, used_idx,
1038                                                  zmbuf->desc_idx);
1039                                 nr_updated += 1;
1040
1041                                 TAILQ_REMOVE(&vq->zmbuf_list, zmbuf, next);
1042                                 rte_pktmbuf_free(zmbuf->mbuf);
1043                                 put_zmbuf(zmbuf);
1044                                 vq->nr_zmbuf -= 1;
1045                         }
1046                 }
1047
1048                 update_used_idx(dev, vq, nr_updated);
1049         }
1050
1051         /*
1052          * Construct a RARP broadcast packet, and inject it to the "pkts"
1053          * array, to looks like that guest actually send such packet.
1054          *
1055          * Check user_send_rarp() for more information.
1056          */
1057         if (unlikely(rte_atomic16_cmpset((volatile uint16_t *)
1058                                          &dev->broadcast_rarp.cnt, 1, 0))) {
1059                 rarp_mbuf = rte_pktmbuf_alloc(mbuf_pool);
1060                 if (rarp_mbuf == NULL) {
1061                         RTE_LOG(ERR, VHOST_DATA,
1062                                 "Failed to allocate memory for mbuf.\n");
1063                         return 0;
1064                 }
1065
1066                 if (make_rarp_packet(rarp_mbuf, &dev->mac)) {
1067                         rte_pktmbuf_free(rarp_mbuf);
1068                         rarp_mbuf = NULL;
1069                 } else {
1070                         count -= 1;
1071                 }
1072         }
1073
1074         free_entries = *((volatile uint16_t *)&vq->avail->idx) -
1075                         vq->last_avail_idx;
1076         if (free_entries == 0)
1077                 goto out;
1078
1079         LOG_DEBUG(VHOST_DATA, "(%d) %s\n", dev->vid, __func__);
1080
1081         /* Prefetch available and used ring */
1082         avail_idx = vq->last_avail_idx & (vq->size - 1);
1083         used_idx  = vq->last_used_idx  & (vq->size - 1);
1084         rte_prefetch0(&vq->avail->ring[avail_idx]);
1085         rte_prefetch0(&vq->used->ring[used_idx]);
1086
1087         count = RTE_MIN(count, MAX_PKT_BURST);
1088         count = RTE_MIN(count, free_entries);
1089         LOG_DEBUG(VHOST_DATA, "(%d) about to dequeue %u buffers\n",
1090                         dev->vid, count);
1091
1092         /* Retrieve all of the head indexes first to avoid caching issues. */
1093         for (i = 0; i < count; i++) {
1094                 avail_idx = (vq->last_avail_idx + i) & (vq->size - 1);
1095                 used_idx  = (vq->last_used_idx  + i) & (vq->size - 1);
1096                 desc_indexes[i] = vq->avail->ring[avail_idx];
1097
1098                 if (likely(dev->dequeue_zero_copy == 0))
1099                         update_used_ring(dev, vq, used_idx, desc_indexes[i]);
1100         }
1101
1102         /* Prefetch descriptor index. */
1103         rte_prefetch0(&vq->desc[desc_indexes[0]]);
1104         for (i = 0; i < count; i++) {
1105                 struct vring_desc *desc;
1106                 uint16_t sz, idx;
1107                 int err;
1108
1109                 if (likely(i + 1 < count))
1110                         rte_prefetch0(&vq->desc[desc_indexes[i + 1]]);
1111
1112                 if (vq->desc[desc_indexes[i]].flags & VRING_DESC_F_INDIRECT) {
1113                         desc = (struct vring_desc *)(uintptr_t)gpa_to_vva(dev,
1114                                         vq->desc[desc_indexes[i]].addr);
1115                         if (unlikely(!desc))
1116                                 break;
1117
1118                         rte_prefetch0(desc);
1119                         sz = vq->desc[desc_indexes[i]].len / sizeof(*desc);
1120                         idx = 0;
1121                 } else {
1122                         desc = vq->desc;
1123                         sz = vq->size;
1124                         idx = desc_indexes[i];
1125                 }
1126
1127                 pkts[i] = rte_pktmbuf_alloc(mbuf_pool);
1128                 if (unlikely(pkts[i] == NULL)) {
1129                         RTE_LOG(ERR, VHOST_DATA,
1130                                 "Failed to allocate memory for mbuf.\n");
1131                         break;
1132                 }
1133
1134                 err = copy_desc_to_mbuf(dev, desc, sz, pkts[i], idx, mbuf_pool);
1135                 if (unlikely(err)) {
1136                         rte_pktmbuf_free(pkts[i]);
1137                         break;
1138                 }
1139
1140                 if (unlikely(dev->dequeue_zero_copy)) {
1141                         struct zcopy_mbuf *zmbuf;
1142
1143                         zmbuf = get_zmbuf(vq);
1144                         if (!zmbuf) {
1145                                 rte_pktmbuf_free(pkts[i]);
1146                                 break;
1147                         }
1148                         zmbuf->mbuf = pkts[i];
1149                         zmbuf->desc_idx = desc_indexes[i];
1150
1151                         /*
1152                          * Pin lock the mbuf; we will check later to see
1153                          * whether the mbuf is freed (when we are the last
1154                          * user) or not. If that's the case, we then could
1155                          * update the used ring safely.
1156                          */
1157                         rte_mbuf_refcnt_update(pkts[i], 1);
1158
1159                         vq->nr_zmbuf += 1;
1160                         TAILQ_INSERT_TAIL(&vq->zmbuf_list, zmbuf, next);
1161                 }
1162         }
1163         vq->last_avail_idx += i;
1164
1165         if (likely(dev->dequeue_zero_copy == 0)) {
1166                 vq->last_used_idx += i;
1167                 update_used_idx(dev, vq, i);
1168         }
1169
1170 out:
1171         if (unlikely(rarp_mbuf != NULL)) {
1172                 /*
1173                  * Inject it to the head of "pkts" array, so that switch's mac
1174                  * learning table will get updated first.
1175                  */
1176                 memmove(&pkts[1], pkts, i * sizeof(struct rte_mbuf *));
1177                 pkts[0] = rarp_mbuf;
1178                 i += 1;
1179         }
1180
1181         return i;
1182 }