lib/librte_vhost/virtio_net.c

   1 /* SPDX-License-Identifier: BSD-3-Clause
   2  * Copyright(c) 2010-2016 Intel Corporation
   3  */
   4
   5 #include <stdint.h>
   6 #include <stdbool.h>
   7 #include <linux/virtio_net.h>
   8
   9 #include <rte_mbuf.h>
  10 #include <rte_memcpy.h>
  11 #include <rte_ether.h>
  12 #include <rte_ip.h>
  13 #include <rte_vhost.h>
  14 #include <rte_tcp.h>
  15 #include <rte_udp.h>
  16 #include <rte_sctp.h>
  17 #include <rte_arp.h>
  18 #include <rte_spinlock.h>
  19 #include <rte_malloc.h>
  20
  21 #include "iotlb.h"
  22 #include "vhost.h"
  23
  24 #define MAX_PKT_BURST 32
  25
  26 #define MAX_BATCH_LEN 256
  27
  28 static  __rte_always_inline bool
  29 rxvq_is_mergeable(struct virtio_net *dev)
  30 {
  31         return dev->features & (1ULL << VIRTIO_NET_F_MRG_RXBUF);
  32 }
  33
  34 static bool
  35 is_valid_virt_queue_idx(uint32_t idx, int is_tx, uint32_t nr_vring)
  36 {
  37         return (is_tx ^ (idx & 1)) == 0 && idx < nr_vring;
  38 }
  39
  40 static __rte_always_inline void
  41 do_flush_shadow_used_ring_split(struct virtio_net *dev,
  42                         struct vhost_virtqueue *vq,
  43                         uint16_t to, uint16_t from, uint16_t size)
  44 {
  45         rte_memcpy(&vq->used->ring[to],
  46                         &vq->shadow_used_split[from],
  47                         size * sizeof(struct vring_used_elem));
  48         vhost_log_cache_used_vring(dev, vq,
  49                         offsetof(struct vring_used, ring[to]),
  50                         size * sizeof(struct vring_used_elem));
  51 }
  52
  53 static __rte_always_inline void
  54 flush_shadow_used_ring_split(struct virtio_net *dev, struct vhost_virtqueue *vq)
  55 {
  56         uint16_t used_idx = vq->last_used_idx & (vq->size - 1);
  57
  58         if (used_idx + vq->shadow_used_idx <= vq->size) {
  59                 do_flush_shadow_used_ring_split(dev, vq, used_idx, 0,
  60                                           vq->shadow_used_idx);
  61         } else {
  62                 uint16_t size;
  63
  64                 /* update used ring interval [used_idx, vq->size] */
  65                 size = vq->size - used_idx;
  66                 do_flush_shadow_used_ring_split(dev, vq, used_idx, 0, size);
  67
  68                 /* update the left half used ring interval [0, left_size] */
  69                 do_flush_shadow_used_ring_split(dev, vq, 0, size,
  70                                           vq->shadow_used_idx - size);
  71         }
  72         vq->last_used_idx += vq->shadow_used_idx;
  73
  74         rte_smp_wmb();
  75
  76         vhost_log_cache_sync(dev, vq);
  77
  78         *(volatile uint16_t *)&vq->used->idx += vq->shadow_used_idx;
  79         vq->shadow_used_idx = 0;
  80         vhost_log_used_vring(dev, vq, offsetof(struct vring_used, idx),
  81                 sizeof(vq->used->idx));
  82 }
  83
  84 static __rte_always_inline void
  85 update_shadow_used_ring_split(struct vhost_virtqueue *vq,
  86                          uint16_t desc_idx, uint32_t len)
  87 {
  88         uint16_t i = vq->shadow_used_idx++;
  89
  90         vq->shadow_used_split[i].id  = desc_idx;
  91         vq->shadow_used_split[i].len = len;
  92 }
  93
  94 static __rte_always_inline void
  95 flush_shadow_used_ring_packed(struct virtio_net *dev,
  96                         struct vhost_virtqueue *vq)
  97 {
  98         int i;
  99         uint16_t used_idx = vq->last_used_idx;
 100         uint16_t head_idx = vq->last_used_idx;
 101         uint16_t head_flags = 0;
 102
 103         /* Split loop in two to save memory barriers */
 104         for (i = 0; i < vq->shadow_used_idx; i++) {
 105                 vq->desc_packed[used_idx].id = vq->shadow_used_packed[i].id;
 106                 vq->desc_packed[used_idx].len = vq->shadow_used_packed[i].len;
 107
 108                 used_idx += vq->shadow_used_packed[i].count;
 109                 if (used_idx >= vq->size)
 110                         used_idx -= vq->size;
 111         }
 112
 113         rte_smp_wmb();
 114
 115         for (i = 0; i < vq->shadow_used_idx; i++) {
 116                 uint16_t flags;
 117
 118                 if (vq->shadow_used_packed[i].len)
 119                         flags = VRING_DESC_F_WRITE;
 120                 else
 121                         flags = 0;
 122
 123                 if (vq->used_wrap_counter) {
 124                         flags |= VRING_DESC_F_USED;
 125                         flags |= VRING_DESC_F_AVAIL;
 126                 } else {
 127                         flags &= ~VRING_DESC_F_USED;
 128                         flags &= ~VRING_DESC_F_AVAIL;
 129                 }
 130
 131                 if (i > 0) {
 132                         vq->desc_packed[vq->last_used_idx].flags = flags;
 133
 134                         vhost_log_cache_used_vring(dev, vq,
 135                                         vq->last_used_idx *
 136                                         sizeof(struct vring_packed_desc),
 137                                         sizeof(struct vring_packed_desc));
 138                 } else {
 139                         head_idx = vq->last_used_idx;
 140                         head_flags = flags;
 141                 }
 142
 143                 vq->last_used_idx += vq->shadow_used_packed[i].count;
 144                 if (vq->last_used_idx >= vq->size) {
 145                         vq->used_wrap_counter ^= 1;
 146                         vq->last_used_idx -= vq->size;
 147                 }
 148         }
 149
 150         vq->desc_packed[head_idx].flags = head_flags;
 151
 152         vhost_log_cache_used_vring(dev, vq,
 153                                 head_idx *
 154                                 sizeof(struct vring_packed_desc),
 155                                 sizeof(struct vring_packed_desc));
 156
 157         vq->shadow_used_idx = 0;
 158         vhost_log_cache_sync(dev, vq);
 159 }
 160
 161 static __rte_always_inline void
 162 update_shadow_used_ring_packed(struct vhost_virtqueue *vq,
 163                          uint16_t desc_idx, uint32_t len, uint16_t count)
 164 {
 165         uint16_t i = vq->shadow_used_idx++;
 166
 167         vq->shadow_used_packed[i].id  = desc_idx;
 168         vq->shadow_used_packed[i].len = len;
 169         vq->shadow_used_packed[i].count = count;
 170 }
 171
 172 static inline void
 173 do_data_copy_enqueue(struct virtio_net *dev, struct vhost_virtqueue *vq)
 174 {
 175         struct batch_copy_elem *elem = vq->batch_copy_elems;
 176         uint16_t count = vq->batch_copy_nb_elems;
 177         int i;
 178
 179         for (i = 0; i < count; i++) {
 180                 rte_memcpy(elem[i].dst, elem[i].src, elem[i].len);
 181                 vhost_log_cache_write(dev, vq, elem[i].log_addr, elem[i].len);
 182                 PRINT_PACKET(dev, (uintptr_t)elem[i].dst, elem[i].len, 0);
 183         }
 184
 185         vq->batch_copy_nb_elems = 0;
 186 }
 187
 188 static inline void
 189 do_data_copy_dequeue(struct vhost_virtqueue *vq)
 190 {
 191         struct batch_copy_elem *elem = vq->batch_copy_elems;
 192         uint16_t count = vq->batch_copy_nb_elems;
 193         int i;
 194
 195         for (i = 0; i < count; i++)
 196                 rte_memcpy(elem[i].dst, elem[i].src, elem[i].len);
 197
 198         vq->batch_copy_nb_elems = 0;
 199 }
 200
 201 /* avoid write operation when necessary, to lessen cache issues */
 202 #define ASSIGN_UNLESS_EQUAL(var, val) do {      \
 203         if ((var) != (val))                     \
 204                 (var) = (val);                  \
 205 } while (0)
 206
 207 static __rte_always_inline void
 208 virtio_enqueue_offload(struct rte_mbuf *m_buf, struct virtio_net_hdr *net_hdr)
 209 {
 210         uint64_t csum_l4 = m_buf->ol_flags & PKT_TX_L4_MASK;
 211
 212         if (m_buf->ol_flags & PKT_TX_TCP_SEG)
 213                 csum_l4 |= PKT_TX_TCP_CKSUM;
 214
 215         if (csum_l4) {
 216                 net_hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
 217                 net_hdr->csum_start = m_buf->l2_len + m_buf->l3_len;
 218
 219                 switch (csum_l4) {
 220                 case PKT_TX_TCP_CKSUM:
 221                         net_hdr->csum_offset = (offsetof(struct tcp_hdr,
 222                                                 cksum));
 223                         break;
 224                 case PKT_TX_UDP_CKSUM:
 225                         net_hdr->csum_offset = (offsetof(struct udp_hdr,
 226                                                 dgram_cksum));
 227                         break;
 228                 case PKT_TX_SCTP_CKSUM:
 229                         net_hdr->csum_offset = (offsetof(struct sctp_hdr,
 230                                                 cksum));
 231                         break;
 232                 }
 233         } else {
 234                 ASSIGN_UNLESS_EQUAL(net_hdr->csum_start, 0);
 235                 ASSIGN_UNLESS_EQUAL(net_hdr->csum_offset, 0);
 236                 ASSIGN_UNLESS_EQUAL(net_hdr->flags, 0);
 237         }
 238
 239         /* IP cksum verification cannot be bypassed, then calculate here */
 240         if (m_buf->ol_flags & PKT_TX_IP_CKSUM) {
 241                 struct ipv4_hdr *ipv4_hdr;
 242
 243                 ipv4_hdr = rte_pktmbuf_mtod_offset(m_buf, struct ipv4_hdr *,
 244                                                    m_buf->l2_len);
 245                 ipv4_hdr->hdr_checksum = rte_ipv4_cksum(ipv4_hdr);
 246         }
 247
 248         if (m_buf->ol_flags & PKT_TX_TCP_SEG) {
 249                 if (m_buf->ol_flags & PKT_TX_IPV4)
 250                         net_hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
 251                 else
 252                         net_hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
 253                 net_hdr->gso_size = m_buf->tso_segsz;
 254                 net_hdr->hdr_len = m_buf->l2_len + m_buf->l3_len
 255                                         + m_buf->l4_len;
 256         } else if (m_buf->ol_flags & PKT_TX_UDP_SEG) {
 257                 net_hdr->gso_type = VIRTIO_NET_HDR_GSO_UDP;
 258                 net_hdr->gso_size = m_buf->tso_segsz;
 259                 net_hdr->hdr_len = m_buf->l2_len + m_buf->l3_len +
 260                         m_buf->l4_len;
 261         } else {
 262                 ASSIGN_UNLESS_EQUAL(net_hdr->gso_type, 0);
 263                 ASSIGN_UNLESS_EQUAL(net_hdr->gso_size, 0);
 264                 ASSIGN_UNLESS_EQUAL(net_hdr->hdr_len, 0);
 265         }
 266 }
 267
 268 static __rte_always_inline int
 269 map_one_desc(struct virtio_net *dev, struct vhost_virtqueue *vq,
 270                 struct buf_vector *buf_vec, uint16_t *vec_idx,
 271                 uint64_t desc_iova, uint64_t desc_len, uint8_t perm)
 272 {
 273         uint16_t vec_id = *vec_idx;
 274
 275         while (desc_len) {
 276                 uint64_t desc_addr;
 277                 uint64_t desc_chunck_len = desc_len;
 278
 279                 if (unlikely(vec_id >= BUF_VECTOR_MAX))
 280                         return -1;
 281
 282                 desc_addr = vhost_iova_to_vva(dev, vq,
 283                                 desc_iova,
 284                                 &desc_chunck_len,
 285                                 perm);
 286                 if (unlikely(!desc_addr))
 287                         return -1;
 288
 289                 buf_vec[vec_id].buf_iova = desc_iova;
 290                 buf_vec[vec_id].buf_addr = desc_addr;
 291                 buf_vec[vec_id].buf_len  = desc_chunck_len;
 292
 293                 desc_len -= desc_chunck_len;
 294                 desc_iova += desc_chunck_len;
 295                 vec_id++;
 296         }
 297         *vec_idx = vec_id;
 298
 299         return 0;
 300 }
 301
 302 static __rte_always_inline int
 303 fill_vec_buf_split(struct virtio_net *dev, struct vhost_virtqueue *vq,
 304                          uint32_t avail_idx, uint16_t *vec_idx,
 305                          struct buf_vector *buf_vec, uint16_t *desc_chain_head,
 306                          uint32_t *desc_chain_len, uint8_t perm)
 307 {
 308         uint16_t idx = vq->avail->ring[avail_idx & (vq->size - 1)];
 309         uint16_t vec_id = *vec_idx;
 310         uint32_t len    = 0;
 311         uint64_t dlen;
 312         uint32_t nr_descs = vq->size;
 313         uint32_t cnt    = 0;
 314         struct vring_desc *descs = vq->desc;
 315         struct vring_desc *idesc = NULL;
 316
 317         if (unlikely(idx >= vq->size))
 318                 return -1;
 319
 320         *desc_chain_head = idx;
 321
 322         if (vq->desc[idx].flags & VRING_DESC_F_INDIRECT) {
 323                 dlen = vq->desc[idx].len;
 324                 nr_descs = dlen / sizeof(struct vring_desc);
 325                 if (unlikely(nr_descs > vq->size))
 326                         return -1;
 327
 328                 descs = (struct vring_desc *)(uintptr_t)
 329                         vhost_iova_to_vva(dev, vq, vq->desc[idx].addr,
 330                                                 &dlen,
 331                                                 VHOST_ACCESS_RO);
 332                 if (unlikely(!descs))
 333                         return -1;
 334
 335                 if (unlikely(dlen < vq->desc[idx].len)) {
 336                         /*
 337                          * The indirect desc table is not contiguous
 338                          * in process VA space, we have to copy it.
 339                          */
 340                         idesc = alloc_copy_ind_table(dev, vq,
 341                                         vq->desc[idx].addr, vq->desc[idx].len);
 342                         if (unlikely(!idesc))
 343                                 return -1;
 344
 345                         descs = idesc;
 346                 }
 347
 348                 idx = 0;
 349         }
 350
 351         while (1) {
 352                 if (unlikely(idx >= nr_descs || cnt++ >= nr_descs)) {
 353                         free_ind_table(idesc);
 354                         return -1;
 355                 }
 356
 357                 len += descs[idx].len;
 358
 359                 if (unlikely(map_one_desc(dev, vq, buf_vec, &vec_id,
 360                                                 descs[idx].addr, descs[idx].len,
 361                                                 perm))) {
 362                         free_ind_table(idesc);
 363                         return -1;
 364                 }
 365
 366                 if ((descs[idx].flags & VRING_DESC_F_NEXT) == 0)
 367                         break;
 368
 369                 idx = descs[idx].next;
 370         }
 371
 372         *desc_chain_len = len;
 373         *vec_idx = vec_id;
 374
 375         if (unlikely(!!idesc))
 376                 free_ind_table(idesc);
 377
 378         return 0;
 379 }
 380
 381 /*
 382  * Returns -1 on fail, 0 on success
 383  */
 384 static inline int
 385 reserve_avail_buf_split(struct virtio_net *dev, struct vhost_virtqueue *vq,
 386                                 uint32_t size, struct buf_vector *buf_vec,
 387                                 uint16_t *num_buffers, uint16_t avail_head,
 388                                 uint16_t *nr_vec)
 389 {
 390         uint16_t cur_idx;
 391         uint16_t vec_idx = 0;
 392         uint16_t max_tries, tries = 0;
 393
 394         uint16_t head_idx = 0;
 395         uint32_t len = 0;
 396
 397         *num_buffers = 0;
 398         cur_idx  = vq->last_avail_idx;
 399
 400         if (rxvq_is_mergeable(dev))
 401                 max_tries = vq->size - 1;
 402         else
 403                 max_tries = 1;
 404
 405         while (size > 0) {
 406                 if (unlikely(cur_idx == avail_head))
 407                         return -1;
 408                 /*
 409                  * if we tried all available ring items, and still
 410                  * can't get enough buf, it means something abnormal
 411                  * happened.
 412                  */
 413                 if (unlikely(++tries > max_tries))
 414                         return -1;
 415
 416                 if (unlikely(fill_vec_buf_split(dev, vq, cur_idx,
 417                                                 &vec_idx, buf_vec,
 418                                                 &head_idx, &len,
 419                                                 VHOST_ACCESS_RW) < 0))
 420                         return -1;
 421                 len = RTE_MIN(len, size);
 422                 update_shadow_used_ring_split(vq, head_idx, len);
 423                 size -= len;
 424
 425                 cur_idx++;
 426                 *num_buffers += 1;
 427         }
 428
 429         *nr_vec = vec_idx;
 430
 431         return 0;
 432 }
 433
 434 static __rte_always_inline int
 435 fill_vec_buf_packed_indirect(struct virtio_net *dev,
 436                         struct vhost_virtqueue *vq,
 437                         struct vring_packed_desc *desc, uint16_t *vec_idx,
 438                         struct buf_vector *buf_vec, uint32_t *len, uint8_t perm)
 439 {
 440         uint16_t i;
 441         uint32_t nr_descs;
 442         uint16_t vec_id = *vec_idx;
 443         uint64_t dlen;
 444         struct vring_packed_desc *descs, *idescs = NULL;
 445
 446         dlen = desc->len;
 447         descs = (struct vring_packed_desc *)(uintptr_t)
 448                 vhost_iova_to_vva(dev, vq, desc->addr, &dlen, VHOST_ACCESS_RO);
 449         if (unlikely(!descs))
 450                 return -1;
 451
 452         if (unlikely(dlen < desc->len)) {
 453                 /*
 454                  * The indirect desc table is not contiguous
 455                  * in process VA space, we have to copy it.
 456                  */
 457                 idescs = alloc_copy_ind_table(dev, vq, desc->addr, desc->len);
 458                 if (unlikely(!idescs))
 459                         return -1;
 460
 461                 descs = idescs;
 462         }
 463
 464         nr_descs =  desc->len / sizeof(struct vring_packed_desc);
 465         if (unlikely(nr_descs >= vq->size)) {
 466                 free_ind_table(idescs);
 467                 return -1;
 468         }
 469
 470         for (i = 0; i < nr_descs; i++) {
 471                 if (unlikely(vec_id >= BUF_VECTOR_MAX)) {
 472                         free_ind_table(idescs);
 473                         return -1;
 474                 }
 475
 476                 *len += descs[i].len;
 477                 if (unlikely(map_one_desc(dev, vq, buf_vec, &vec_id,
 478                                                 descs[i].addr, descs[i].len,
 479                                                 perm)))
 480                         return -1;
 481         }
 482         *vec_idx = vec_id;
 483
 484         if (unlikely(!!idescs))
 485                 free_ind_table(idescs);
 486
 487         return 0;
 488 }
 489
 490 static __rte_always_inline int
 491 fill_vec_buf_packed(struct virtio_net *dev, struct vhost_virtqueue *vq,
 492                                 uint16_t avail_idx, uint16_t *desc_count,
 493                                 struct buf_vector *buf_vec, uint16_t *vec_idx,
 494                                 uint16_t *buf_id, uint32_t *len, uint8_t perm)
 495 {
 496         bool wrap_counter = vq->avail_wrap_counter;
 497         struct vring_packed_desc *descs = vq->desc_packed;
 498         uint16_t vec_id = *vec_idx;
 499
 500         if (avail_idx < vq->last_avail_idx)
 501                 wrap_counter ^= 1;
 502
 503         if (unlikely(!desc_is_avail(&descs[avail_idx], wrap_counter)))
 504                 return -1;
 505
 506         /*
 507          * The ordering between desc flags and desc
 508          * content reads need to be enforced.
 509          */
 510         rte_smp_rmb();
 511
 512         *desc_count = 0;
 513         *len = 0;
 514
 515         while (1) {
 516                 if (unlikely(vec_id >= BUF_VECTOR_MAX))
 517                         return -1;
 518
 519                 if (unlikely(*desc_count >= vq->size))
 520                         return -1;
 521
 522                 *desc_count += 1;
 523                 *buf_id = descs[avail_idx].id;
 524
 525                 if (descs[avail_idx].flags & VRING_DESC_F_INDIRECT) {
 526                         if (unlikely(fill_vec_buf_packed_indirect(dev, vq,
 527                                                         &descs[avail_idx],
 528                                                         &vec_id, buf_vec,
 529                                                         len, perm) < 0))
 530                                 return -1;
 531                 } else {
 532                         *len += descs[avail_idx].len;
 533
 534                         if (unlikely(map_one_desc(dev, vq, buf_vec, &vec_id,
 535                                                         descs[avail_idx].addr,
 536                                                         descs[avail_idx].len,
 537                                                         perm)))
 538                                 return -1;
 539                 }
 540
 541                 if ((descs[avail_idx].flags & VRING_DESC_F_NEXT) == 0)
 542                         break;
 543
 544                 if (++avail_idx >= vq->size) {
 545                         avail_idx -= vq->size;
 546                         wrap_counter ^= 1;
 547                 }
 548         }
 549
 550         *vec_idx = vec_id;
 551
 552         return 0;
 553 }
 554
 555 /*
 556  * Returns -1 on fail, 0 on success
 557  */
 558 static inline int
 559 reserve_avail_buf_packed(struct virtio_net *dev, struct vhost_virtqueue *vq,
 560                                 uint32_t size, struct buf_vector *buf_vec,
 561                                 uint16_t *nr_vec, uint16_t *num_buffers,
 562                                 uint16_t *nr_descs)
 563 {
 564         uint16_t avail_idx;
 565         uint16_t vec_idx = 0;
 566         uint16_t max_tries, tries = 0;
 567
 568         uint16_t buf_id = 0;
 569         uint32_t len = 0;
 570         uint16_t desc_count;
 571
 572         *num_buffers = 0;
 573         avail_idx = vq->last_avail_idx;
 574
 575         if (rxvq_is_mergeable(dev))
 576                 max_tries = vq->size - 1;
 577         else
 578                 max_tries = 1;
 579
 580         while (size > 0) {
 581                 /*
 582                  * if we tried all available ring items, and still
 583                  * can't get enough buf, it means something abnormal
 584                  * happened.
 585                  */
 586                 if (unlikely(++tries > max_tries))
 587                         return -1;
 588
 589                 if (unlikely(fill_vec_buf_packed(dev, vq,
 590                                                 avail_idx, &desc_count,
 591                                                 buf_vec, &vec_idx,
 592                                                 &buf_id, &len,
 593                                                 VHOST_ACCESS_RW) < 0))
 594                         return -1;
 595
 596                 len = RTE_MIN(len, size);
 597                 update_shadow_used_ring_packed(vq, buf_id, len, desc_count);
 598                 size -= len;
 599
 600                 avail_idx += desc_count;
 601                 if (avail_idx >= vq->size)
 602                         avail_idx -= vq->size;
 603
 604                 *nr_descs += desc_count;
 605                 *num_buffers += 1;
 606         }
 607
 608         *nr_vec = vec_idx;
 609
 610         return 0;
 611 }
 612
 613 static __rte_always_inline int
 614 copy_mbuf_to_desc(struct virtio_net *dev, struct vhost_virtqueue *vq,
 615                             struct rte_mbuf *m, struct buf_vector *buf_vec,
 616                             uint16_t nr_vec, uint16_t num_buffers)
 617 {
 618         uint32_t vec_idx = 0;
 619         uint32_t mbuf_offset, mbuf_avail;
 620         uint32_t buf_offset, buf_avail;
 621         uint64_t buf_addr, buf_iova, buf_len;
 622         uint32_t cpy_len;
 623         uint64_t hdr_addr;
 624         struct rte_mbuf *hdr_mbuf;
 625         struct batch_copy_elem *batch_copy = vq->batch_copy_elems;
 626         struct virtio_net_hdr_mrg_rxbuf tmp_hdr, *hdr = NULL;
 627         int error = 0;
 628
 629         if (unlikely(m == NULL)) {
 630                 error = -1;
 631                 goto out;
 632         }
 633
 634         buf_addr = buf_vec[vec_idx].buf_addr;
 635         buf_iova = buf_vec[vec_idx].buf_iova;
 636         buf_len = buf_vec[vec_idx].buf_len;
 637
 638         if (nr_vec > 1)
 639                 rte_prefetch0((void *)(uintptr_t)buf_vec[1].buf_addr);
 640
 641         if (unlikely(buf_len < dev->vhost_hlen && nr_vec <= 1)) {
 642                 error = -1;
 643                 goto out;
 644         }
 645
 646         hdr_mbuf = m;
 647         hdr_addr = buf_addr;
 648         if (unlikely(buf_len < dev->vhost_hlen))
 649                 hdr = &tmp_hdr;
 650         else
 651                 hdr = (struct virtio_net_hdr_mrg_rxbuf *)(uintptr_t)hdr_addr;
 652
 653         VHOST_LOG_DEBUG(VHOST_DATA, "(%d) RX: num merge buffers %d\n",
 654                 dev->vid, num_buffers);
 655
 656         if (unlikely(buf_len < dev->vhost_hlen)) {
 657                 buf_offset = dev->vhost_hlen - buf_len;
 658                 vec_idx++;
 659                 buf_addr = buf_vec[vec_idx].buf_addr;
 660                 buf_iova = buf_vec[vec_idx].buf_iova;
 661                 buf_len = buf_vec[vec_idx].buf_len;
 662                 buf_avail = buf_len - buf_offset;
 663         } else {
 664                 buf_offset = dev->vhost_hlen;
 665                 buf_avail = buf_len - dev->vhost_hlen;
 666         }
 667
 668         mbuf_avail  = rte_pktmbuf_data_len(m);
 669         mbuf_offset = 0;
 670         while (mbuf_avail != 0 || m->next != NULL) {
 671                 /* done with current buf, get the next one */
 672                 if (buf_avail == 0) {
 673                         vec_idx++;
 674                         if (unlikely(vec_idx >= nr_vec)) {
 675                                 error = -1;
 676                                 goto out;
 677                         }
 678
 679                         buf_addr = buf_vec[vec_idx].buf_addr;
 680                         buf_iova = buf_vec[vec_idx].buf_iova;
 681                         buf_len = buf_vec[vec_idx].buf_len;
 682
 683                         /* Prefetch next buffer address. */
 684                         if (vec_idx + 1 < nr_vec)
 685                                 rte_prefetch0((void *)(uintptr_t)
 686                                                 buf_vec[vec_idx + 1].buf_addr);
 687                         buf_offset = 0;
 688                         buf_avail  = buf_len;
 689                 }
 690
 691                 /* done with current mbuf, get the next one */
 692                 if (mbuf_avail == 0) {
 693                         m = m->next;
 694
 695                         mbuf_offset = 0;
 696                         mbuf_avail  = rte_pktmbuf_data_len(m);
 697                 }
 698
 699                 if (hdr_addr) {
 700                         virtio_enqueue_offload(hdr_mbuf, &hdr->hdr);
 701                         if (rxvq_is_mergeable(dev))
 702                                 ASSIGN_UNLESS_EQUAL(hdr->num_buffers,
 703                                                 num_buffers);
 704
 705                         if (unlikely(hdr == &tmp_hdr)) {
 706                                 uint64_t len;
 707                                 uint64_t remain = dev->vhost_hlen;
 708                                 uint64_t src = (uint64_t)(uintptr_t)hdr, dst;
 709                                 uint64_t iova = buf_vec[0].buf_iova;
 710                                 uint16_t hdr_vec_idx = 0;
 711
 712                                 while (remain) {
 713                                         len = RTE_MIN(remain,
 714                                                 buf_vec[hdr_vec_idx].buf_len);
 715                                         dst = buf_vec[hdr_vec_idx].buf_addr;
 716                                         rte_memcpy((void *)(uintptr_t)dst,
 717                                                         (void *)(uintptr_t)src,
 718                                                         len);
 719
 720                                         PRINT_PACKET(dev, (uintptr_t)dst,
 721                                                         (uint32_t)len, 0);
 722                                         vhost_log_cache_write(dev, vq,
 723                                                         iova, len);
 724
 725                                         remain -= len;
 726                                         iova += len;
 727                                         src += len;
 728                                         hdr_vec_idx++;
 729                                 }
 730                         } else {
 731                                 PRINT_PACKET(dev, (uintptr_t)hdr_addr,
 732                                                 dev->vhost_hlen, 0);
 733                                 vhost_log_cache_write(dev, vq,
 734                                                 buf_vec[0].buf_iova,
 735                                                 dev->vhost_hlen);
 736                         }
 737
 738                         hdr_addr = 0;
 739                 }
 740
 741                 cpy_len = RTE_MIN(buf_avail, mbuf_avail);
 742
 743                 if (likely(cpy_len > MAX_BATCH_LEN ||
 744                                         vq->batch_copy_nb_elems >= vq->size)) {
 745                         rte_memcpy((void *)((uintptr_t)(buf_addr + buf_offset)),
 746                                 rte_pktmbuf_mtod_offset(m, void *, mbuf_offset),
 747                                 cpy_len);
 748                         vhost_log_cache_write(dev, vq, buf_iova + buf_offset,
 749                                         cpy_len);
 750                         PRINT_PACKET(dev, (uintptr_t)(buf_addr + buf_offset),
 751                                 cpy_len, 0);
 752                 } else {
 753                         batch_copy[vq->batch_copy_nb_elems].dst =
 754                                 (void *)((uintptr_t)(buf_addr + buf_offset));
 755                         batch_copy[vq->batch_copy_nb_elems].src =
 756                                 rte_pktmbuf_mtod_offset(m, void *, mbuf_offset);
 757                         batch_copy[vq->batch_copy_nb_elems].log_addr =
 758                                 buf_iova + buf_offset;
 759                         batch_copy[vq->batch_copy_nb_elems].len = cpy_len;
 760                         vq->batch_copy_nb_elems++;
 761                 }
 762
 763                 mbuf_avail  -= cpy_len;
 764                 mbuf_offset += cpy_len;
 765                 buf_avail  -= cpy_len;
 766                 buf_offset += cpy_len;
 767         }
 768
 769 out:
 770
 771         return error;
 772 }
 773
 774 static __rte_always_inline uint32_t
 775 virtio_dev_rx_split(struct virtio_net *dev, struct vhost_virtqueue *vq,
 776         struct rte_mbuf **pkts, uint32_t count)
 777 {
 778         uint32_t pkt_idx = 0;
 779         uint16_t num_buffers;
 780         struct buf_vector buf_vec[BUF_VECTOR_MAX];
 781         uint16_t avail_head;
 782
 783         avail_head = *((volatile uint16_t *)&vq->avail->idx);
 784
 785         /*
 786          * The ordering between avail index and
 787          * desc reads needs to be enforced.
 788          */
 789         rte_smp_rmb();
 790
 791         rte_prefetch0(&vq->avail->ring[vq->last_avail_idx & (vq->size - 1)]);
 792
 793         for (pkt_idx = 0; pkt_idx < count; pkt_idx++) {
 794                 uint32_t pkt_len = pkts[pkt_idx]->pkt_len + dev->vhost_hlen;
 795                 uint16_t nr_vec = 0;
 796
 797                 if (unlikely(reserve_avail_buf_split(dev, vq,
 798                                                 pkt_len, buf_vec, &num_buffers,
 799                                                 avail_head, &nr_vec) < 0)) {
 800                         VHOST_LOG_DEBUG(VHOST_DATA,
 801                                 "(%d) failed to get enough desc from vring\n",
 802                                 dev->vid);
 803                         vq->shadow_used_idx -= num_buffers;
 804                         break;
 805                 }
 806
 807                 rte_prefetch0((void *)(uintptr_t)buf_vec[0].buf_addr);
 808
 809                 VHOST_LOG_DEBUG(VHOST_DATA, "(%d) current index %d | end index %d\n",
 810                         dev->vid, vq->last_avail_idx,
 811                         vq->last_avail_idx + num_buffers);
 812
 813                 if (copy_mbuf_to_desc(dev, vq, pkts[pkt_idx],
 814                                                 buf_vec, nr_vec,
 815                                                 num_buffers) < 0) {
 816                         vq->shadow_used_idx -= num_buffers;
 817                         break;
 818                 }
 819
 820                 vq->last_avail_idx += num_buffers;
 821         }
 822
 823         do_data_copy_enqueue(dev, vq);
 824
 825         if (likely(vq->shadow_used_idx)) {
 826                 flush_shadow_used_ring_split(dev, vq);
 827                 vhost_vring_call_split(dev, vq);
 828         }
 829
 830         return pkt_idx;
 831 }
 832
 833 static __rte_always_inline uint32_t
 834 virtio_dev_rx_packed(struct virtio_net *dev, struct vhost_virtqueue *vq,
 835         struct rte_mbuf **pkts, uint32_t count)
 836 {
 837         uint32_t pkt_idx = 0;
 838         uint16_t num_buffers;
 839         struct buf_vector buf_vec[BUF_VECTOR_MAX];
 840
 841         for (pkt_idx = 0; pkt_idx < count; pkt_idx++) {
 842                 uint32_t pkt_len = pkts[pkt_idx]->pkt_len + dev->vhost_hlen;
 843                 uint16_t nr_vec = 0;
 844                 uint16_t nr_descs = 0;
 845
 846                 if (unlikely(reserve_avail_buf_packed(dev, vq,
 847                                                 pkt_len, buf_vec, &nr_vec,
 848                                                 &num_buffers, &nr_descs) < 0)) {
 849                         VHOST_LOG_DEBUG(VHOST_DATA,
 850                                 "(%d) failed to get enough desc from vring\n",
 851                                 dev->vid);
 852                         vq->shadow_used_idx -= num_buffers;
 853                         break;
 854                 }
 855
 856                 rte_prefetch0((void *)(uintptr_t)buf_vec[0].buf_addr);
 857
 858                 VHOST_LOG_DEBUG(VHOST_DATA, "(%d) current index %d | end index %d\n",
 859                         dev->vid, vq->last_avail_idx,
 860                         vq->last_avail_idx + num_buffers);
 861
 862                 if (copy_mbuf_to_desc(dev, vq, pkts[pkt_idx],
 863                                                 buf_vec, nr_vec,
 864                                                 num_buffers) < 0) {
 865                         vq->shadow_used_idx -= num_buffers;
 866                         break;
 867                 }
 868
 869                 vq->last_avail_idx += nr_descs;
 870                 if (vq->last_avail_idx >= vq->size) {
 871                         vq->last_avail_idx -= vq->size;
 872                         vq->avail_wrap_counter ^= 1;
 873                 }
 874         }
 875
 876         do_data_copy_enqueue(dev, vq);
 877
 878         if (likely(vq->shadow_used_idx)) {
 879                 flush_shadow_used_ring_packed(dev, vq);
 880                 vhost_vring_call_packed(dev, vq);
 881         }
 882
 883         return pkt_idx;
 884 }
 885
 886 static __rte_always_inline uint32_t
 887 virtio_dev_rx(struct virtio_net *dev, uint16_t queue_id,
 888         struct rte_mbuf **pkts, uint32_t count)
 889 {
 890         struct vhost_virtqueue *vq;
 891         uint32_t nb_tx = 0;
 892
 893         VHOST_LOG_DEBUG(VHOST_DATA, "(%d) %s\n", dev->vid, __func__);
 894         if (unlikely(!is_valid_virt_queue_idx(queue_id, 0, dev->nr_vring))) {
 895                 RTE_LOG(ERR, VHOST_DATA, "(%d) %s: invalid virtqueue idx %d.\n",
 896                         dev->vid, __func__, queue_id);
 897                 return 0;
 898         }
 899
 900         vq = dev->virtqueue[queue_id];
 901
 902         rte_spinlock_lock(&vq->access_lock);
 903
 904         if (unlikely(vq->enabled == 0))
 905                 goto out_access_unlock;
 906
 907         if (dev->features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))
 908                 vhost_user_iotlb_rd_lock(vq);
 909
 910         if (unlikely(vq->access_ok == 0))
 911                 if (unlikely(vring_translate(dev, vq) < 0))
 912                         goto out;
 913
 914         count = RTE_MIN((uint32_t)MAX_PKT_BURST, count);
 915         if (count == 0)
 916                 goto out;
 917
 918         if (vq_is_packed(dev))
 919                 nb_tx = virtio_dev_rx_packed(dev, vq, pkts, count);
 920         else
 921                 nb_tx = virtio_dev_rx_split(dev, vq, pkts, count);
 922
 923 out:
 924         if (dev->features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))
 925                 vhost_user_iotlb_rd_unlock(vq);
 926
 927 out_access_unlock:
 928         rte_spinlock_unlock(&vq->access_lock);
 929
 930         return nb_tx;
 931 }
 932
 933 uint16_t
 934 rte_vhost_enqueue_burst(int vid, uint16_t queue_id,
 935         struct rte_mbuf **pkts, uint16_t count)
 936 {
 937         struct virtio_net *dev = get_device(vid);
 938
 939         if (!dev)
 940                 return 0;
 941
 942         if (unlikely(!(dev->flags & VIRTIO_DEV_BUILTIN_VIRTIO_NET))) {
 943                 RTE_LOG(ERR, VHOST_DATA,
 944                         "(%d) %s: built-in vhost net backend is disabled.\n",
 945                         dev->vid, __func__);
 946                 return 0;
 947         }
 948
 949         return virtio_dev_rx(dev, queue_id, pkts, count);
 950 }
 951
 952 static inline bool
 953 virtio_net_with_host_offload(struct virtio_net *dev)
 954 {
 955         if (dev->features &
 956                         ((1ULL << VIRTIO_NET_F_CSUM) |
 957                          (1ULL << VIRTIO_NET_F_HOST_ECN) |
 958                          (1ULL << VIRTIO_NET_F_HOST_TSO4) |
 959                          (1ULL << VIRTIO_NET_F_HOST_TSO6) |
 960                          (1ULL << VIRTIO_NET_F_HOST_UFO)))
 961                 return true;
 962
 963         return false;
 964 }
 965
 966 static void
 967 parse_ethernet(struct rte_mbuf *m, uint16_t *l4_proto, void **l4_hdr)
 968 {
 969         struct ipv4_hdr *ipv4_hdr;
 970         struct ipv6_hdr *ipv6_hdr;
 971         void *l3_hdr = NULL;
 972         struct ether_hdr *eth_hdr;
 973         uint16_t ethertype;
 974
 975         eth_hdr = rte_pktmbuf_mtod(m, struct ether_hdr *);
 976
 977         m->l2_len = sizeof(struct ether_hdr);
 978         ethertype = rte_be_to_cpu_16(eth_hdr->ether_type);
 979
 980         if (ethertype == ETHER_TYPE_VLAN) {
 981                 struct vlan_hdr *vlan_hdr = (struct vlan_hdr *)(eth_hdr + 1);
 982
 983                 m->l2_len += sizeof(struct vlan_hdr);
 984                 ethertype = rte_be_to_cpu_16(vlan_hdr->eth_proto);
 985         }
 986
 987         l3_hdr = (char *)eth_hdr + m->l2_len;
 988
 989         switch (ethertype) {
 990         case ETHER_TYPE_IPv4:
 991                 ipv4_hdr = l3_hdr;
 992                 *l4_proto = ipv4_hdr->next_proto_id;
 993                 m->l3_len = (ipv4_hdr->version_ihl & 0x0f) * 4;
 994                 *l4_hdr = (char *)l3_hdr + m->l3_len;
 995                 m->ol_flags |= PKT_TX_IPV4;
 996                 break;
 997         case ETHER_TYPE_IPv6:
 998                 ipv6_hdr = l3_hdr;
 999                 *l4_proto = ipv6_hdr->proto;
1000                 m->l3_len = sizeof(struct ipv6_hdr);
1001                 *l4_hdr = (char *)l3_hdr + m->l3_len;
1002                 m->ol_flags |= PKT_TX_IPV6;
1003                 break;
1004         default:
1005                 m->l3_len = 0;
1006                 *l4_proto = 0;
1007                 *l4_hdr = NULL;
1008                 break;
1009         }
1010 }
1011
1012 static __rte_always_inline void
1013 vhost_dequeue_offload(struct virtio_net_hdr *hdr, struct rte_mbuf *m)
1014 {
1015         uint16_t l4_proto = 0;
1016         void *l4_hdr = NULL;
1017         struct tcp_hdr *tcp_hdr = NULL;
1018
1019         if (hdr->flags == 0 && hdr->gso_type == VIRTIO_NET_HDR_GSO_NONE)
1020                 return;
1021
1022         parse_ethernet(m, &l4_proto, &l4_hdr);
1023         if (hdr->flags == VIRTIO_NET_HDR_F_NEEDS_CSUM) {
1024                 if (hdr->csum_start == (m->l2_len + m->l3_len)) {
1025                         switch (hdr->csum_offset) {
1026                         case (offsetof(struct tcp_hdr, cksum)):
1027                                 if (l4_proto == IPPROTO_TCP)
1028                                         m->ol_flags |= PKT_TX_TCP_CKSUM;
1029                                 break;
1030                         case (offsetof(struct udp_hdr, dgram_cksum)):
1031                                 if (l4_proto == IPPROTO_UDP)
1032                                         m->ol_flags |= PKT_TX_UDP_CKSUM;
1033                                 break;
1034                         case (offsetof(struct sctp_hdr, cksum)):
1035                                 if (l4_proto == IPPROTO_SCTP)
1036                                         m->ol_flags |= PKT_TX_SCTP_CKSUM;
1037                                 break;
1038                         default:
1039                                 break;
1040                         }
1041                 }
1042         }
1043
1044         if (l4_hdr && hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) {
1045                 switch (hdr->gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
1046                 case VIRTIO_NET_HDR_GSO_TCPV4:
1047                 case VIRTIO_NET_HDR_GSO_TCPV6:
1048                         tcp_hdr = l4_hdr;
1049                         m->ol_flags |= PKT_TX_TCP_SEG;
1050                         m->tso_segsz = hdr->gso_size;
1051                         m->l4_len = (tcp_hdr->data_off & 0xf0) >> 2;
1052                         break;
1053                 case VIRTIO_NET_HDR_GSO_UDP:
1054                         m->ol_flags |= PKT_TX_UDP_SEG;
1055                         m->tso_segsz = hdr->gso_size;
1056                         m->l4_len = sizeof(struct udp_hdr);
1057                         break;
1058                 default:
1059                         RTE_LOG(WARNING, VHOST_DATA,
1060                                 "unsupported gso type %u.\n", hdr->gso_type);
1061                         break;
1062                 }
1063         }
1064 }
1065
1066 static __rte_always_inline int
1067 copy_desc_to_mbuf(struct virtio_net *dev, struct vhost_virtqueue *vq,
1068                   struct buf_vector *buf_vec, uint16_t nr_vec,
1069                   struct rte_mbuf *m, struct rte_mempool *mbuf_pool)
1070 {
1071         uint32_t buf_avail, buf_offset;
1072         uint64_t buf_addr, buf_iova, buf_len;
1073         uint32_t mbuf_avail, mbuf_offset;
1074         uint32_t cpy_len;
1075         struct rte_mbuf *cur = m, *prev = m;
1076         struct virtio_net_hdr tmp_hdr;
1077         struct virtio_net_hdr *hdr = NULL;
1078         /* A counter to avoid desc dead loop chain */
1079         uint16_t vec_idx = 0;
1080         struct batch_copy_elem *batch_copy = vq->batch_copy_elems;
1081         int error = 0;
1082
1083         buf_addr = buf_vec[vec_idx].buf_addr;
1084         buf_iova = buf_vec[vec_idx].buf_iova;
1085         buf_len = buf_vec[vec_idx].buf_len;
1086
1087         if (unlikely(buf_len < dev->vhost_hlen && nr_vec <= 1)) {
1088                 error = -1;
1089                 goto out;
1090         }
1091
1092         if (likely(nr_vec > 1))
1093                 rte_prefetch0((void *)(uintptr_t)buf_vec[1].buf_addr);
1094
1095         if (virtio_net_with_host_offload(dev)) {
1096                 if (unlikely(buf_len < sizeof(struct virtio_net_hdr))) {
1097                         uint64_t len;
1098                         uint64_t remain = sizeof(struct virtio_net_hdr);
1099                         uint64_t src;
1100                         uint64_t dst = (uint64_t)(uintptr_t)&tmp_hdr;
1101                         uint16_t hdr_vec_idx = 0;
1102
1103                         /*
1104                          * No luck, the virtio-net header doesn't fit
1105                          * in a contiguous virtual area.
1106                          */
1107                         while (remain) {
1108                                 len = RTE_MIN(remain,
1109                                         buf_vec[hdr_vec_idx].buf_len);
1110                                 src = buf_vec[hdr_vec_idx].buf_addr;
1111                                 rte_memcpy((void *)(uintptr_t)dst,
1112                                                    (void *)(uintptr_t)src, len);
1113
1114                                 remain -= len;
1115                                 dst += len;
1116                                 hdr_vec_idx++;
1117                         }
1118
1119                         hdr = &tmp_hdr;
1120                 } else {
1121                         hdr = (struct virtio_net_hdr *)((uintptr_t)buf_addr);
1122                         rte_prefetch0(hdr);
1123                 }
1124         }
1125
1126         /*
1127          * A virtio driver normally uses at least 2 desc buffers
1128          * for Tx: the first for storing the header, and others
1129          * for storing the data.
1130          */
1131         if (unlikely(buf_len < dev->vhost_hlen)) {
1132                 buf_offset = dev->vhost_hlen - buf_len;
1133                 vec_idx++;
1134                 buf_addr = buf_vec[vec_idx].buf_addr;
1135                 buf_iova = buf_vec[vec_idx].buf_iova;
1136                 buf_len = buf_vec[vec_idx].buf_len;
1137                 buf_avail  = buf_len - buf_offset;
1138         } else if (buf_len == dev->vhost_hlen) {
1139                 if (unlikely(++vec_idx >= nr_vec))
1140                         goto out;
1141                 buf_addr = buf_vec[vec_idx].buf_addr;
1142                 buf_iova = buf_vec[vec_idx].buf_iova;
1143                 buf_len = buf_vec[vec_idx].buf_len;
1144
1145                 buf_offset = 0;
1146                 buf_avail = buf_len;
1147         } else {
1148                 buf_offset = dev->vhost_hlen;
1149                 buf_avail = buf_vec[vec_idx].buf_len - dev->vhost_hlen;
1150         }
1151
1152         rte_prefetch0((void *)(uintptr_t)
1153                         (buf_addr + buf_offset));
1154
1155         PRINT_PACKET(dev,
1156                         (uintptr_t)(buf_addr + buf_offset),
1157                         (uint32_t)buf_avail, 0);
1158
1159         mbuf_offset = 0;
1160         mbuf_avail  = m->buf_len - RTE_PKTMBUF_HEADROOM;
1161         while (1) {
1162                 uint64_t hpa;
1163
1164                 cpy_len = RTE_MIN(buf_avail, mbuf_avail);
1165
1166                 /*
1167                  * A desc buf might across two host physical pages that are
1168                  * not continuous. In such case (gpa_to_hpa returns 0), data
1169                  * will be copied even though zero copy is enabled.
1170                  */
1171                 if (unlikely(dev->dequeue_zero_copy && (hpa = gpa_to_hpa(dev,
1172                                         buf_iova + buf_offset, cpy_len)))) {
1173                         cur->data_len = cpy_len;
1174                         cur->data_off = 0;
1175                         cur->buf_addr =
1176                                 (void *)(uintptr_t)(buf_addr + buf_offset);
1177                         cur->buf_iova = hpa;
1178
1179                         /*
1180                          * In zero copy mode, one mbuf can only reference data
1181                          * for one or partial of one desc buff.
1182                          */
1183                         mbuf_avail = cpy_len;
1184                 } else {
1185                         if (likely(cpy_len > MAX_BATCH_LEN ||
1186                                    vq->batch_copy_nb_elems >= vq->size ||
1187                                    (hdr && cur == m))) {
1188                                 rte_memcpy(rte_pktmbuf_mtod_offset(cur, void *,
1189                                                                    mbuf_offset),
1190                                            (void *)((uintptr_t)(buf_addr +
1191                                                            buf_offset)),
1192                                            cpy_len);
1193                         } else {
1194                                 batch_copy[vq->batch_copy_nb_elems].dst =
1195                                         rte_pktmbuf_mtod_offset(cur, void *,
1196                                                                 mbuf_offset);
1197                                 batch_copy[vq->batch_copy_nb_elems].src =
1198                                         (void *)((uintptr_t)(buf_addr +
1199                                                                 buf_offset));
1200                                 batch_copy[vq->batch_copy_nb_elems].len =
1201                                         cpy_len;
1202                                 vq->batch_copy_nb_elems++;
1203                         }
1204                 }
1205
1206                 mbuf_avail  -= cpy_len;
1207                 mbuf_offset += cpy_len;
1208                 buf_avail -= cpy_len;
1209                 buf_offset += cpy_len;
1210
1211                 /* This buf reaches to its end, get the next one */
1212                 if (buf_avail == 0) {
1213                         if (++vec_idx >= nr_vec)
1214                                 break;
1215
1216                         buf_addr = buf_vec[vec_idx].buf_addr;
1217                         buf_iova = buf_vec[vec_idx].buf_iova;
1218                         buf_len = buf_vec[vec_idx].buf_len;
1219
1220                         /*
1221                          * Prefecth desc n + 1 buffer while
1222                          * desc n buffer is processed.
1223                          */
1224                         if (vec_idx + 1 < nr_vec)
1225                                 rte_prefetch0((void *)(uintptr_t)
1226                                                 buf_vec[vec_idx + 1].buf_addr);
1227
1228                         buf_offset = 0;
1229                         buf_avail  = buf_len;
1230
1231                         PRINT_PACKET(dev, (uintptr_t)buf_addr,
1232                                         (uint32_t)buf_avail, 0);
1233                 }
1234
1235                 /*
1236                  * This mbuf reaches to its end, get a new one
1237                  * to hold more data.
1238                  */
1239                 if (mbuf_avail == 0) {
1240                         cur = rte_pktmbuf_alloc(mbuf_pool);
1241                         if (unlikely(cur == NULL)) {
1242                                 RTE_LOG(ERR, VHOST_DATA, "Failed to "
1243                                         "allocate memory for mbuf.\n");
1244                                 error = -1;
1245                                 goto out;
1246                         }
1247                         if (unlikely(dev->dequeue_zero_copy))
1248                                 rte_mbuf_refcnt_update(cur, 1);
1249
1250                         prev->next = cur;
1251                         prev->data_len = mbuf_offset;
1252                         m->nb_segs += 1;
1253                         m->pkt_len += mbuf_offset;
1254                         prev = cur;
1255
1256                         mbuf_offset = 0;
1257                         mbuf_avail  = cur->buf_len - RTE_PKTMBUF_HEADROOM;
1258                 }
1259         }
1260
1261         prev->data_len = mbuf_offset;
1262         m->pkt_len    += mbuf_offset;
1263
1264         if (hdr)
1265                 vhost_dequeue_offload(hdr, m);
1266
1267 out:
1268
1269         return error;
1270 }
1271
1272 static __rte_always_inline struct zcopy_mbuf *
1273 get_zmbuf(struct vhost_virtqueue *vq)
1274 {
1275         uint16_t i;
1276         uint16_t last;
1277         int tries = 0;
1278
1279         /* search [last_zmbuf_idx, zmbuf_size) */
1280         i = vq->last_zmbuf_idx;
1281         last = vq->zmbuf_size;
1282
1283 again:
1284         for (; i < last; i++) {
1285                 if (vq->zmbufs[i].in_use == 0) {
1286                         vq->last_zmbuf_idx = i + 1;
1287                         vq->zmbufs[i].in_use = 1;
1288                         return &vq->zmbufs[i];
1289                 }
1290         }
1291
1292         tries++;
1293         if (tries == 1) {
1294                 /* search [0, last_zmbuf_idx) */
1295                 i = 0;
1296                 last = vq->last_zmbuf_idx;
1297                 goto again;
1298         }
1299
1300         return NULL;
1301 }
1302
1303 static __rte_always_inline uint16_t
1304 virtio_dev_tx_split(struct virtio_net *dev, struct vhost_virtqueue *vq,
1305         struct rte_mempool *mbuf_pool, struct rte_mbuf **pkts, uint16_t count)
1306 {
1307         uint16_t i;
1308         uint16_t free_entries;
1309
1310         if (unlikely(dev->dequeue_zero_copy)) {
1311                 struct zcopy_mbuf *zmbuf, *next;
1312
1313                 for (zmbuf = TAILQ_FIRST(&vq->zmbuf_list);
1314                      zmbuf != NULL; zmbuf = next) {
1315                         next = TAILQ_NEXT(zmbuf, next);
1316
1317                         if (mbuf_is_consumed(zmbuf->mbuf)) {
1318                                 update_shadow_used_ring_split(vq,
1319                                                 zmbuf->desc_idx, 0);
1320                                 TAILQ_REMOVE(&vq->zmbuf_list, zmbuf, next);
1321                                 restore_mbuf(zmbuf->mbuf);
1322                                 rte_pktmbuf_free(zmbuf->mbuf);
1323                                 put_zmbuf(zmbuf);
1324                                 vq->nr_zmbuf -= 1;
1325                         }
1326                 }
1327
1328                 if (likely(vq->shadow_used_idx)) {
1329                         flush_shadow_used_ring_split(dev, vq);
1330                         vhost_vring_call_split(dev, vq);
1331                 }
1332         }
1333
1334         free_entries = *((volatile uint16_t *)&vq->avail->idx) -
1335                         vq->last_avail_idx;
1336         if (free_entries == 0)
1337                 return 0;
1338
1339         /*
1340          * The ordering between avail index and
1341          * desc reads needs to be enforced.
1342          */
1343         rte_smp_rmb();
1344
1345         rte_prefetch0(&vq->avail->ring[vq->last_avail_idx & (vq->size - 1)]);
1346
1347         VHOST_LOG_DEBUG(VHOST_DATA, "(%d) %s\n", dev->vid, __func__);
1348
1349         count = RTE_MIN(count, MAX_PKT_BURST);
1350         count = RTE_MIN(count, free_entries);
1351         VHOST_LOG_DEBUG(VHOST_DATA, "(%d) about to dequeue %u buffers\n",
1352                         dev->vid, count);
1353
1354         for (i = 0; i < count; i++) {
1355                 struct buf_vector buf_vec[BUF_VECTOR_MAX];
1356                 uint16_t head_idx;
1357                 uint32_t dummy_len;
1358                 uint16_t nr_vec = 0;
1359                 int err;
1360
1361                 if (unlikely(fill_vec_buf_split(dev, vq,
1362                                                 vq->last_avail_idx + i,
1363                                                 &nr_vec, buf_vec,
1364                                                 &head_idx, &dummy_len,
1365                                                 VHOST_ACCESS_RO) < 0))
1366                         break;
1367
1368                 if (likely(dev->dequeue_zero_copy == 0))
1369                         update_shadow_used_ring_split(vq, head_idx, 0);
1370
1371                 rte_prefetch0((void *)(uintptr_t)buf_vec[0].buf_addr);
1372
1373                 pkts[i] = rte_pktmbuf_alloc(mbuf_pool);
1374                 if (unlikely(pkts[i] == NULL)) {
1375                         RTE_LOG(ERR, VHOST_DATA,
1376                                 "Failed to allocate memory for mbuf.\n");
1377                         break;
1378                 }
1379
1380                 err = copy_desc_to_mbuf(dev, vq, buf_vec, nr_vec, pkts[i],
1381                                 mbuf_pool);
1382                 if (unlikely(err)) {
1383                         rte_pktmbuf_free(pkts[i]);
1384                         break;
1385                 }
1386
1387                 if (unlikely(dev->dequeue_zero_copy)) {
1388                         struct zcopy_mbuf *zmbuf;
1389
1390                         zmbuf = get_zmbuf(vq);
1391                         if (!zmbuf) {
1392                                 rte_pktmbuf_free(pkts[i]);
1393                                 break;
1394                         }
1395                         zmbuf->mbuf = pkts[i];
1396                         zmbuf->desc_idx = head_idx;
1397
1398                         /*
1399                          * Pin lock the mbuf; we will check later to see
1400                          * whether the mbuf is freed (when we are the last
1401                          * user) or not. If that's the case, we then could
1402                          * update the used ring safely.
1403                          */
1404                         rte_mbuf_refcnt_update(pkts[i], 1);
1405
1406                         vq->nr_zmbuf += 1;
1407                         TAILQ_INSERT_TAIL(&vq->zmbuf_list, zmbuf, next);
1408                 }
1409         }
1410         vq->last_avail_idx += i;
1411
1412         if (likely(dev->dequeue_zero_copy == 0)) {
1413                 do_data_copy_dequeue(vq);
1414                 if (unlikely(i < count))
1415                         vq->shadow_used_idx = i;
1416                 if (likely(vq->shadow_used_idx)) {
1417                         flush_shadow_used_ring_split(dev, vq);
1418                         vhost_vring_call_split(dev, vq);
1419                 }
1420         }
1421
1422         return i;
1423 }
1424
1425 static __rte_always_inline uint16_t
1426 virtio_dev_tx_packed(struct virtio_net *dev, struct vhost_virtqueue *vq,
1427         struct rte_mempool *mbuf_pool, struct rte_mbuf **pkts, uint16_t count)
1428 {
1429         uint16_t i;
1430
1431         if (unlikely(dev->dequeue_zero_copy)) {
1432                 struct zcopy_mbuf *zmbuf, *next;
1433
1434                 for (zmbuf = TAILQ_FIRST(&vq->zmbuf_list);
1435                      zmbuf != NULL; zmbuf = next) {
1436                         next = TAILQ_NEXT(zmbuf, next);
1437
1438                         if (mbuf_is_consumed(zmbuf->mbuf)) {
1439                                 update_shadow_used_ring_packed(vq,
1440                                                 zmbuf->desc_idx,
1441                                                 0,
1442                                                 zmbuf->desc_count);
1443
1444                                 TAILQ_REMOVE(&vq->zmbuf_list, zmbuf, next);
1445                                 restore_mbuf(zmbuf->mbuf);
1446                                 rte_pktmbuf_free(zmbuf->mbuf);
1447                                 put_zmbuf(zmbuf);
1448                                 vq->nr_zmbuf -= 1;
1449                         }
1450                 }
1451
1452                 if (likely(vq->shadow_used_idx)) {
1453                         flush_shadow_used_ring_packed(dev, vq);
1454                         vhost_vring_call_packed(dev, vq);
1455                 }
1456         }
1457
1458         VHOST_LOG_DEBUG(VHOST_DATA, "(%d) %s\n", dev->vid, __func__);
1459
1460         count = RTE_MIN(count, MAX_PKT_BURST);
1461         VHOST_LOG_DEBUG(VHOST_DATA, "(%d) about to dequeue %u buffers\n",
1462                         dev->vid, count);
1463
1464         for (i = 0; i < count; i++) {
1465                 struct buf_vector buf_vec[BUF_VECTOR_MAX];
1466                 uint16_t buf_id;
1467                 uint32_t dummy_len;
1468                 uint16_t desc_count, nr_vec = 0;
1469                 int err;
1470
1471                 if (unlikely(fill_vec_buf_packed(dev, vq,
1472                                                 vq->last_avail_idx, &desc_count,
1473                                                 buf_vec, &nr_vec,
1474                                                 &buf_id, &dummy_len,
1475                                                 VHOST_ACCESS_RO) < 0))
1476                         break;
1477
1478                 if (likely(dev->dequeue_zero_copy == 0))
1479                         update_shadow_used_ring_packed(vq, buf_id, 0,
1480                                         desc_count);
1481
1482                 rte_prefetch0((void *)(uintptr_t)buf_vec[0].buf_addr);
1483
1484                 pkts[i] = rte_pktmbuf_alloc(mbuf_pool);
1485                 if (unlikely(pkts[i] == NULL)) {
1486                         RTE_LOG(ERR, VHOST_DATA,
1487                                 "Failed to allocate memory for mbuf.\n");
1488                         break;
1489                 }
1490
1491                 err = copy_desc_to_mbuf(dev, vq, buf_vec, nr_vec, pkts[i],
1492                                 mbuf_pool);
1493                 if (unlikely(err)) {
1494                         rte_pktmbuf_free(pkts[i]);
1495                         break;
1496                 }
1497
1498                 if (unlikely(dev->dequeue_zero_copy)) {
1499                         struct zcopy_mbuf *zmbuf;
1500
1501                         zmbuf = get_zmbuf(vq);
1502                         if (!zmbuf) {
1503                                 rte_pktmbuf_free(pkts[i]);
1504                                 break;
1505                         }
1506                         zmbuf->mbuf = pkts[i];
1507                         zmbuf->desc_idx = buf_id;
1508                         zmbuf->desc_count = desc_count;
1509
1510                         /*
1511                          * Pin lock the mbuf; we will check later to see
1512                          * whether the mbuf is freed (when we are the last
1513                          * user) or not. If that's the case, we then could
1514                          * update the used ring safely.
1515                          */
1516                         rte_mbuf_refcnt_update(pkts[i], 1);
1517
1518                         vq->nr_zmbuf += 1;
1519                         TAILQ_INSERT_TAIL(&vq->zmbuf_list, zmbuf, next);
1520                 }
1521
1522                 vq->last_avail_idx += desc_count;
1523                 if (vq->last_avail_idx >= vq->size) {
1524                         vq->last_avail_idx -= vq->size;
1525                         vq->avail_wrap_counter ^= 1;
1526                 }
1527         }
1528
1529         if (likely(dev->dequeue_zero_copy == 0)) {
1530                 do_data_copy_dequeue(vq);
1531                 if (unlikely(i < count))
1532                         vq->shadow_used_idx = i;
1533                 if (likely(vq->shadow_used_idx)) {
1534                         flush_shadow_used_ring_packed(dev, vq);
1535                         vhost_vring_call_packed(dev, vq);
1536                 }
1537         }
1538
1539         return i;
1540 }
1541
1542 uint16_t
1543 rte_vhost_dequeue_burst(int vid, uint16_t queue_id,
1544         struct rte_mempool *mbuf_pool, struct rte_mbuf **pkts, uint16_t count)
1545 {
1546         struct virtio_net *dev;
1547         struct rte_mbuf *rarp_mbuf = NULL;
1548         struct vhost_virtqueue *vq;
1549
1550         dev = get_device(vid);
1551         if (!dev)
1552                 return 0;
1553
1554         if (unlikely(!(dev->flags & VIRTIO_DEV_BUILTIN_VIRTIO_NET))) {
1555                 RTE_LOG(ERR, VHOST_DATA,
1556                         "(%d) %s: built-in vhost net backend is disabled.\n",
1557                         dev->vid, __func__);
1558                 return 0;
1559         }
1560
1561         if (unlikely(!is_valid_virt_queue_idx(queue_id, 1, dev->nr_vring))) {
1562                 RTE_LOG(ERR, VHOST_DATA, "(%d) %s: invalid virtqueue idx %d.\n",
1563                         dev->vid, __func__, queue_id);
1564                 return 0;
1565         }
1566
1567         vq = dev->virtqueue[queue_id];
1568
1569         if (unlikely(rte_spinlock_trylock(&vq->access_lock) == 0))
1570                 return 0;
1571
1572         if (unlikely(vq->enabled == 0)) {
1573                 count = 0;
1574                 goto out_access_unlock;
1575         }
1576
1577         if (dev->features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))
1578                 vhost_user_iotlb_rd_lock(vq);
1579
1580         if (unlikely(vq->access_ok == 0))
1581                 if (unlikely(vring_translate(dev, vq) < 0)) {
1582                         count = 0;
1583                         goto out;
1584                 }
1585
1586         /*
1587          * Construct a RARP broadcast packet, and inject it to the "pkts"
1588          * array, to looks like that guest actually send such packet.
1589          *
1590          * Check user_send_rarp() for more information.
1591          *
1592          * broadcast_rarp shares a cacheline in the virtio_net structure
1593          * with some fields that are accessed during enqueue and
1594          * rte_atomic16_cmpset() causes a write if using cmpxchg. This could
1595          * result in false sharing between enqueue and dequeue.
1596          *
1597          * Prevent unnecessary false sharing by reading broadcast_rarp first
1598          * and only performing cmpset if the read indicates it is likely to
1599          * be set.
1600          */
1601         if (unlikely(rte_atomic16_read(&dev->broadcast_rarp) &&
1602                         rte_atomic16_cmpset((volatile uint16_t *)
1603                                 &dev->broadcast_rarp.cnt, 1, 0))) {
1604
1605                 rarp_mbuf = rte_net_make_rarp_packet(mbuf_pool, &dev->mac);
1606                 if (rarp_mbuf == NULL) {
1607                         RTE_LOG(ERR, VHOST_DATA,
1608                                 "Failed to make RARP packet.\n");
1609                         count = 0;
1610                         goto out;
1611                 }
1612                 count -= 1;
1613         }
1614
1615         if (vq_is_packed(dev))
1616                 count = virtio_dev_tx_packed(dev, vq, mbuf_pool, pkts, count);
1617         else
1618                 count = virtio_dev_tx_split(dev, vq, mbuf_pool, pkts, count);
1619
1620 out:
1621         if (dev->features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))
1622                 vhost_user_iotlb_rd_unlock(vq);
1623
1624 out_access_unlock:
1625         rte_spinlock_unlock(&vq->access_lock);
1626
1627         if (unlikely(rarp_mbuf != NULL)) {
1628                 /*
1629                  * Inject it to the head of "pkts" array, so that switch's mac
1630                  * learning table will get updated first.
1631                  */
1632                 memmove(&pkts[1], pkts, count * sizeof(struct rte_mbuf *));
1633                 pkts[0] = rarp_mbuf;
1634                 count += 1;
1635         }
1636
1637         return count;
1638 }