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 bool
  29 is_valid_virt_queue_idx(uint32_t idx, int is_tx, uint32_t nr_vring)
  30 {
  31         return (is_tx ^ (idx & 1)) == 0 && idx < nr_vring;
  32 }
  33
  34 static __rte_always_inline struct vring_desc *
  35 alloc_copy_ind_table(struct virtio_net *dev, struct vhost_virtqueue *vq,
  36                                          struct vring_desc *desc)
  37 {
  38         struct vring_desc *idesc;
  39         uint64_t src, dst;
  40         uint64_t len, remain = desc->len;
  41         uint64_t desc_addr = desc->addr;
  42
  43         idesc = rte_malloc(__func__, desc->len, 0);
  44         if (unlikely(!idesc))
  45                 return 0;
  46
  47         dst = (uint64_t)(uintptr_t)idesc;
  48
  49         while (remain) {
  50                 len = remain;
  51                 src = vhost_iova_to_vva(dev, vq, desc_addr, &len,
  52                                 VHOST_ACCESS_RO);
  53                 if (unlikely(!src || !len)) {
  54                         rte_free(idesc);
  55                         return 0;
  56                 }
  57
  58                 rte_memcpy((void *)(uintptr_t)dst, (void *)(uintptr_t)src, len);
  59
  60                 remain -= len;
  61                 dst += len;
  62                 desc_addr += len;
  63         }
  64
  65         return idesc;
  66 }
  67
  68 static __rte_always_inline void
  69 free_ind_table(struct vring_desc *idesc)
  70 {
  71         rte_free(idesc);
  72 }
  73
  74 static __rte_always_inline void
  75 do_flush_shadow_used_ring(struct virtio_net *dev, struct vhost_virtqueue *vq,
  76                           uint16_t to, uint16_t from, uint16_t size)
  77 {
  78         rte_memcpy(&vq->used->ring[to],
  79                         &vq->shadow_used_ring[from],
  80                         size * sizeof(struct vring_used_elem));
  81         vhost_log_cache_used_vring(dev, vq,
  82                         offsetof(struct vring_used, ring[to]),
  83                         size * sizeof(struct vring_used_elem));
  84 }
  85
  86 static __rte_always_inline void
  87 flush_shadow_used_ring(struct virtio_net *dev, struct vhost_virtqueue *vq)
  88 {
  89         uint16_t used_idx = vq->last_used_idx & (vq->size - 1);
  90
  91         if (used_idx + vq->shadow_used_idx <= vq->size) {
  92                 do_flush_shadow_used_ring(dev, vq, used_idx, 0,
  93                                           vq->shadow_used_idx);
  94         } else {
  95                 uint16_t size;
  96
  97                 /* update used ring interval [used_idx, vq->size] */
  98                 size = vq->size - used_idx;
  99                 do_flush_shadow_used_ring(dev, vq, used_idx, 0, size);
 100
 101                 /* update the left half used ring interval [0, left_size] */
 102                 do_flush_shadow_used_ring(dev, vq, 0, size,
 103                                           vq->shadow_used_idx - size);
 104         }
 105         vq->last_used_idx += vq->shadow_used_idx;
 106
 107         rte_smp_wmb();
 108
 109         vhost_log_cache_sync(dev, vq);
 110
 111         *(volatile uint16_t *)&vq->used->idx += vq->shadow_used_idx;
 112         vhost_log_used_vring(dev, vq, offsetof(struct vring_used, idx),
 113                 sizeof(vq->used->idx));
 114 }
 115
 116 static __rte_always_inline void
 117 update_shadow_used_ring(struct vhost_virtqueue *vq,
 118                          uint16_t desc_idx, uint16_t len)
 119 {
 120         uint16_t i = vq->shadow_used_idx++;
 121
 122         vq->shadow_used_ring[i].id  = desc_idx;
 123         vq->shadow_used_ring[i].len = len;
 124 }
 125
 126 static inline void
 127 do_data_copy_enqueue(struct virtio_net *dev, struct vhost_virtqueue *vq)
 128 {
 129         struct batch_copy_elem *elem = vq->batch_copy_elems;
 130         uint16_t count = vq->batch_copy_nb_elems;
 131         int i;
 132
 133         for (i = 0; i < count; i++) {
 134                 rte_memcpy(elem[i].dst, elem[i].src, elem[i].len);
 135                 vhost_log_cache_write(dev, vq, elem[i].log_addr, elem[i].len);
 136                 PRINT_PACKET(dev, (uintptr_t)elem[i].dst, elem[i].len, 0);
 137         }
 138 }
 139
 140 static inline void
 141 do_data_copy_dequeue(struct vhost_virtqueue *vq)
 142 {
 143         struct batch_copy_elem *elem = vq->batch_copy_elems;
 144         uint16_t count = vq->batch_copy_nb_elems;
 145         int i;
 146
 147         for (i = 0; i < count; i++)
 148                 rte_memcpy(elem[i].dst, elem[i].src, elem[i].len);
 149 }
 150
 151 /* avoid write operation when necessary, to lessen cache issues */
 152 #define ASSIGN_UNLESS_EQUAL(var, val) do {      \
 153         if ((var) != (val))                     \
 154                 (var) = (val);                  \
 155 } while (0)
 156
 157 static void
 158 virtio_enqueue_offload(struct rte_mbuf *m_buf, struct virtio_net_hdr *net_hdr)
 159 {
 160         uint64_t csum_l4 = m_buf->ol_flags & PKT_TX_L4_MASK;
 161
 162         if (m_buf->ol_flags & PKT_TX_TCP_SEG)
 163                 csum_l4 |= PKT_TX_TCP_CKSUM;
 164
 165         if (csum_l4) {
 166                 net_hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
 167                 net_hdr->csum_start = m_buf->l2_len + m_buf->l3_len;
 168
 169                 switch (csum_l4) {
 170                 case PKT_TX_TCP_CKSUM:
 171                         net_hdr->csum_offset = (offsetof(struct tcp_hdr,
 172                                                 cksum));
 173                         break;
 174                 case PKT_TX_UDP_CKSUM:
 175                         net_hdr->csum_offset = (offsetof(struct udp_hdr,
 176                                                 dgram_cksum));
 177                         break;
 178                 case PKT_TX_SCTP_CKSUM:
 179                         net_hdr->csum_offset = (offsetof(struct sctp_hdr,
 180                                                 cksum));
 181                         break;
 182                 }
 183         } else {
 184                 ASSIGN_UNLESS_EQUAL(net_hdr->csum_start, 0);
 185                 ASSIGN_UNLESS_EQUAL(net_hdr->csum_offset, 0);
 186                 ASSIGN_UNLESS_EQUAL(net_hdr->flags, 0);
 187         }
 188
 189         /* IP cksum verification cannot be bypassed, then calculate here */
 190         if (m_buf->ol_flags & PKT_TX_IP_CKSUM) {
 191                 struct ipv4_hdr *ipv4_hdr;
 192
 193                 ipv4_hdr = rte_pktmbuf_mtod_offset(m_buf, struct ipv4_hdr *,
 194                                                    m_buf->l2_len);
 195                 ipv4_hdr->hdr_checksum = rte_ipv4_cksum(ipv4_hdr);
 196         }
 197
 198         if (m_buf->ol_flags & PKT_TX_TCP_SEG) {
 199                 if (m_buf->ol_flags & PKT_TX_IPV4)
 200                         net_hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
 201                 else
 202                         net_hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
 203                 net_hdr->gso_size = m_buf->tso_segsz;
 204                 net_hdr->hdr_len = m_buf->l2_len + m_buf->l3_len
 205                                         + m_buf->l4_len;
 206         } else if (m_buf->ol_flags & PKT_TX_UDP_SEG) {
 207                 net_hdr->gso_type = VIRTIO_NET_HDR_GSO_UDP;
 208                 net_hdr->gso_size = m_buf->tso_segsz;
 209                 net_hdr->hdr_len = m_buf->l2_len + m_buf->l3_len +
 210                         m_buf->l4_len;
 211         } else {
 212                 ASSIGN_UNLESS_EQUAL(net_hdr->gso_type, 0);
 213                 ASSIGN_UNLESS_EQUAL(net_hdr->gso_size, 0);
 214                 ASSIGN_UNLESS_EQUAL(net_hdr->hdr_len, 0);
 215         }
 216 }
 217
 218 static __rte_always_inline int
 219 copy_mbuf_to_desc(struct virtio_net *dev, struct vhost_virtqueue *vq,
 220                   struct vring_desc *descs, struct rte_mbuf *m,
 221                   uint16_t desc_idx, uint32_t size)
 222 {
 223         uint32_t desc_avail, desc_offset;
 224         uint32_t mbuf_avail, mbuf_offset;
 225         uint32_t cpy_len;
 226         uint64_t desc_chunck_len;
 227         struct vring_desc *desc;
 228         uint64_t desc_addr, desc_gaddr;
 229         /* A counter to avoid desc dead loop chain */
 230         uint16_t nr_desc = 1;
 231         struct batch_copy_elem *batch_copy = vq->batch_copy_elems;
 232         uint16_t copy_nb = vq->batch_copy_nb_elems;
 233         int error = 0;
 234
 235         desc = &descs[desc_idx];
 236         desc_chunck_len = desc->len;
 237         desc_gaddr = desc->addr;
 238         desc_addr = vhost_iova_to_vva(dev, vq, desc_gaddr,
 239                                         &desc_chunck_len, VHOST_ACCESS_RW);
 240         /*
 241          * Checking of 'desc_addr' placed outside of 'unlikely' macro to avoid
 242          * performance issue with some versions of gcc (4.8.4 and 5.3.0) which
 243          * otherwise stores offset on the stack instead of in a register.
 244          */
 245         if (unlikely(desc->len < dev->vhost_hlen) || !desc_addr) {
 246                 error = -1;
 247                 goto out;
 248         }
 249
 250         rte_prefetch0((void *)(uintptr_t)desc_addr);
 251
 252         if (likely(desc_chunck_len >= dev->vhost_hlen)) {
 253                 virtio_enqueue_offload(m,
 254                                 (struct virtio_net_hdr *)(uintptr_t)desc_addr);
 255                 PRINT_PACKET(dev, (uintptr_t)desc_addr, dev->vhost_hlen, 0);
 256                 vhost_log_cache_write(dev, vq, desc_gaddr, dev->vhost_hlen);
 257         } else {
 258                 struct virtio_net_hdr vnet_hdr;
 259                 uint64_t remain = dev->vhost_hlen;
 260                 uint64_t len;
 261                 uint64_t src = (uint64_t)(uintptr_t)&vnet_hdr, dst;
 262                 uint64_t guest_addr = desc_gaddr;
 263
 264                 virtio_enqueue_offload(m, &vnet_hdr);
 265
 266                 while (remain) {
 267                         len = remain;
 268                         dst = vhost_iova_to_vva(dev, vq, guest_addr,
 269                                         &len, VHOST_ACCESS_RW);
 270                         if (unlikely(!dst || !len)) {
 271                                 error = -1;
 272                                 goto out;
 273                         }
 274
 275                         rte_memcpy((void *)(uintptr_t)dst,
 276                                         (void *)(uintptr_t)src, len);
 277
 278                         PRINT_PACKET(dev, (uintptr_t)dst, (uint32_t)len, 0);
 279                         vhost_log_cache_write(dev, vq, guest_addr, len);
 280                         remain -= len;
 281                         guest_addr += len;
 282                         src += len;
 283                 }
 284         }
 285
 286         desc_avail  = desc->len - dev->vhost_hlen;
 287         if (unlikely(desc_chunck_len < dev->vhost_hlen)) {
 288                 desc_chunck_len = desc_avail;
 289                 desc_gaddr = desc->addr + dev->vhost_hlen;
 290                 desc_addr = vhost_iova_to_vva(dev,
 291                                 vq, desc_gaddr,
 292                                 &desc_chunck_len,
 293                                 VHOST_ACCESS_RW);
 294                 if (unlikely(!desc_addr)) {
 295                         error = -1;
 296                         goto out;
 297                 }
 298
 299                 desc_offset = 0;
 300         } else {
 301                 desc_offset = dev->vhost_hlen;
 302                 desc_chunck_len -= dev->vhost_hlen;
 303         }
 304
 305         mbuf_avail  = rte_pktmbuf_data_len(m);
 306         mbuf_offset = 0;
 307         while (mbuf_avail != 0 || m->next != NULL) {
 308                 /* done with current mbuf, fetch next */
 309                 if (mbuf_avail == 0) {
 310                         m = m->next;
 311
 312                         mbuf_offset = 0;
 313                         mbuf_avail  = rte_pktmbuf_data_len(m);
 314                 }
 315
 316                 /* done with current desc buf, fetch next */
 317                 if (desc_avail == 0) {
 318                         if ((desc->flags & VRING_DESC_F_NEXT) == 0) {
 319                                 /* Room in vring buffer is not enough */
 320                                 error = -1;
 321                                 goto out;
 322                         }
 323                         if (unlikely(desc->next >= size || ++nr_desc > size)) {
 324                                 error = -1;
 325                                 goto out;
 326                         }
 327
 328                         desc = &descs[desc->next];
 329                         desc_chunck_len = desc->len;
 330                         desc_gaddr = desc->addr;
 331                         desc_addr = vhost_iova_to_vva(dev, vq, desc_gaddr,
 332                                                         &desc_chunck_len,
 333                                                         VHOST_ACCESS_RW);
 334                         if (unlikely(!desc_addr)) {
 335                                 error = -1;
 336                                 goto out;
 337                         }
 338
 339                         desc_offset = 0;
 340                         desc_avail  = desc->len;
 341                 } else if (unlikely(desc_chunck_len == 0)) {
 342                         desc_chunck_len = desc_avail;
 343                         desc_gaddr += desc_offset;
 344                         desc_addr = vhost_iova_to_vva(dev,
 345                                         vq, desc_gaddr,
 346                                         &desc_chunck_len, VHOST_ACCESS_RW);
 347                         if (unlikely(!desc_addr)) {
 348                                 error = -1;
 349                                 goto out;
 350                         }
 351                         desc_offset = 0;
 352                 }
 353
 354                 cpy_len = RTE_MIN(desc_chunck_len, mbuf_avail);
 355                 if (likely(cpy_len > MAX_BATCH_LEN || copy_nb >= vq->size)) {
 356                         rte_memcpy((void *)((uintptr_t)(desc_addr +
 357                                                         desc_offset)),
 358                                 rte_pktmbuf_mtod_offset(m, void *, mbuf_offset),
 359                                 cpy_len);
 360                         vhost_log_cache_write(dev, vq, desc_gaddr + desc_offset,
 361                                         cpy_len);
 362                         PRINT_PACKET(dev, (uintptr_t)(desc_addr + desc_offset),
 363                                      cpy_len, 0);
 364                 } else {
 365                         batch_copy[copy_nb].dst =
 366                                 (void *)((uintptr_t)(desc_addr + desc_offset));
 367                         batch_copy[copy_nb].src =
 368                                 rte_pktmbuf_mtod_offset(m, void *, mbuf_offset);
 369                         batch_copy[copy_nb].log_addr = desc_gaddr + desc_offset;
 370                         batch_copy[copy_nb].len = cpy_len;
 371                         copy_nb++;
 372                 }
 373
 374                 mbuf_avail  -= cpy_len;
 375                 mbuf_offset += cpy_len;
 376                 desc_avail  -= cpy_len;
 377                 desc_offset += cpy_len;
 378                 desc_chunck_len -= cpy_len;
 379         }
 380
 381 out:
 382         vq->batch_copy_nb_elems = copy_nb;
 383
 384         return error;
 385 }
 386
 387 /**
 388  * This function adds buffers to the virtio devices RX virtqueue. Buffers can
 389  * be received from the physical port or from another virtio device. A packet
 390  * count is returned to indicate the number of packets that are successfully
 391  * added to the RX queue. This function works when the mbuf is scattered, but
 392  * it doesn't support the mergeable feature.
 393  */
 394 static __rte_always_inline uint32_t
 395 virtio_dev_rx(struct virtio_net *dev, uint16_t queue_id,
 396               struct rte_mbuf **pkts, uint32_t count)
 397 {
 398         struct vhost_virtqueue *vq;
 399         uint16_t avail_idx, free_entries, start_idx;
 400         uint16_t desc_indexes[MAX_PKT_BURST];
 401         struct vring_desc *descs;
 402         uint16_t used_idx;
 403         uint32_t i, sz;
 404
 405         VHOST_LOG_DEBUG(VHOST_DATA, "(%d) %s\n", dev->vid, __func__);
 406         if (unlikely(!is_valid_virt_queue_idx(queue_id, 0, dev->nr_vring))) {
 407                 RTE_LOG(ERR, VHOST_DATA, "(%d) %s: invalid virtqueue idx %d.\n",
 408                         dev->vid, __func__, queue_id);
 409                 return 0;
 410         }
 411
 412         vq = dev->virtqueue[queue_id];
 413
 414         rte_spinlock_lock(&vq->access_lock);
 415
 416         if (unlikely(vq->enabled == 0))
 417                 goto out_access_unlock;
 418
 419         if (dev->features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))
 420                 vhost_user_iotlb_rd_lock(vq);
 421
 422         if (unlikely(vq->access_ok == 0)) {
 423                 if (unlikely(vring_translate(dev, vq) < 0)) {
 424                         count = 0;
 425                         goto out;
 426                 }
 427         }
 428
 429         avail_idx = *((volatile uint16_t *)&vq->avail->idx);
 430         start_idx = vq->last_used_idx;
 431         free_entries = avail_idx - start_idx;
 432         count = RTE_MIN(count, free_entries);
 433         count = RTE_MIN(count, (uint32_t)MAX_PKT_BURST);
 434         if (count == 0)
 435                 goto out;
 436
 437         VHOST_LOG_DEBUG(VHOST_DATA, "(%d) start_idx %d | end_idx %d\n",
 438                 dev->vid, start_idx, start_idx + count);
 439
 440         vq->batch_copy_nb_elems = 0;
 441
 442         /* Retrieve all of the desc indexes first to avoid caching issues. */
 443         rte_prefetch0(&vq->avail->ring[start_idx & (vq->size - 1)]);
 444         for (i = 0; i < count; i++) {
 445                 used_idx = (start_idx + i) & (vq->size - 1);
 446                 desc_indexes[i] = vq->avail->ring[used_idx];
 447                 vq->used->ring[used_idx].id = desc_indexes[i];
 448                 vq->used->ring[used_idx].len = pkts[i]->pkt_len +
 449                                                dev->vhost_hlen;
 450                 vhost_log_cache_used_vring(dev, vq,
 451                         offsetof(struct vring_used, ring[used_idx]),
 452                         sizeof(vq->used->ring[used_idx]));
 453         }
 454
 455         rte_prefetch0(&vq->desc[desc_indexes[0]]);
 456         for (i = 0; i < count; i++) {
 457                 struct vring_desc *idesc = NULL;
 458                 uint16_t desc_idx = desc_indexes[i];
 459                 int err;
 460
 461                 if (vq->desc[desc_idx].flags & VRING_DESC_F_INDIRECT) {
 462                         uint64_t dlen = vq->desc[desc_idx].len;
 463                         descs = (struct vring_desc *)(uintptr_t)
 464                                 vhost_iova_to_vva(dev,
 465                                                 vq, vq->desc[desc_idx].addr,
 466                                                 &dlen, VHOST_ACCESS_RO);
 467                         if (unlikely(!descs)) {
 468                                 count = i;
 469                                 break;
 470                         }
 471
 472                         if (unlikely(dlen < vq->desc[desc_idx].len)) {
 473                                 /*
 474                                  * The indirect desc table is not contiguous
 475                                  * in process VA space, we have to copy it.
 476                                  */
 477                                 idesc = alloc_copy_ind_table(dev, vq,
 478                                                         &vq->desc[desc_idx]);
 479                                 if (unlikely(!idesc))
 480                                         break;
 481
 482                                 descs = idesc;
 483                         }
 484
 485                         desc_idx = 0;
 486                         sz = vq->desc[desc_idx].len / sizeof(*descs);
 487                 } else {
 488                         descs = vq->desc;
 489                         sz = vq->size;
 490                 }
 491
 492                 err = copy_mbuf_to_desc(dev, vq, descs, pkts[i], desc_idx, sz);
 493                 if (unlikely(err)) {
 494                         count = i;
 495                         free_ind_table(idesc);
 496                         break;
 497                 }
 498
 499                 if (i + 1 < count)
 500                         rte_prefetch0(&vq->desc[desc_indexes[i+1]]);
 501
 502                 if (unlikely(!!idesc))
 503                         free_ind_table(idesc);
 504         }
 505
 506         do_data_copy_enqueue(dev, vq);
 507
 508         rte_smp_wmb();
 509
 510         vhost_log_cache_sync(dev, vq);
 511
 512         *(volatile uint16_t *)&vq->used->idx += count;
 513         vq->last_used_idx += count;
 514         vhost_log_used_vring(dev, vq,
 515                 offsetof(struct vring_used, idx),
 516                 sizeof(vq->used->idx));
 517
 518         vhost_vring_call(dev, vq);
 519 out:
 520         if (dev->features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))
 521                 vhost_user_iotlb_rd_unlock(vq);
 522
 523 out_access_unlock:
 524         rte_spinlock_unlock(&vq->access_lock);
 525
 526         return count;
 527 }
 528
 529 static __rte_always_inline int
 530 fill_vec_buf(struct virtio_net *dev, struct vhost_virtqueue *vq,
 531                          uint32_t avail_idx, uint32_t *vec_idx,
 532                          struct buf_vector *buf_vec, uint16_t *desc_chain_head,
 533                          uint16_t *desc_chain_len)
 534 {
 535         uint16_t idx = vq->avail->ring[avail_idx & (vq->size - 1)];
 536         uint32_t vec_id = *vec_idx;
 537         uint32_t len    = 0;
 538         uint64_t dlen;
 539         struct vring_desc *descs = vq->desc;
 540         struct vring_desc *idesc = NULL;
 541
 542         *desc_chain_head = idx;
 543
 544         if (vq->desc[idx].flags & VRING_DESC_F_INDIRECT) {
 545                 dlen = vq->desc[idx].len;
 546                 descs = (struct vring_desc *)(uintptr_t)
 547                         vhost_iova_to_vva(dev, vq, vq->desc[idx].addr,
 548                                                 &dlen,
 549                                                 VHOST_ACCESS_RO);
 550                 if (unlikely(!descs))
 551                         return -1;
 552
 553                 if (unlikely(dlen < vq->desc[idx].len)) {
 554                         /*
 555                          * The indirect desc table is not contiguous
 556                          * in process VA space, we have to copy it.
 557                          */
 558                         idesc = alloc_copy_ind_table(dev, vq, &vq->desc[idx]);
 559                         if (unlikely(!idesc))
 560                                 return -1;
 561
 562                         descs = idesc;
 563                 }
 564
 565                 idx = 0;
 566         }
 567
 568         while (1) {
 569                 if (unlikely(vec_id >= BUF_VECTOR_MAX || idx >= vq->size)) {
 570                         free_ind_table(idesc);
 571                         return -1;
 572                 }
 573
 574                 len += descs[idx].len;
 575                 buf_vec[vec_id].buf_addr = descs[idx].addr;
 576                 buf_vec[vec_id].buf_len  = descs[idx].len;
 577                 buf_vec[vec_id].desc_idx = idx;
 578                 vec_id++;
 579
 580                 if ((descs[idx].flags & VRING_DESC_F_NEXT) == 0)
 581                         break;
 582
 583                 idx = descs[idx].next;
 584         }
 585
 586         *desc_chain_len = len;
 587         *vec_idx = vec_id;
 588
 589         if (unlikely(!!idesc))
 590                 free_ind_table(idesc);
 591
 592         return 0;
 593 }
 594
 595 /*
 596  * Returns -1 on fail, 0 on success
 597  */
 598 static inline int
 599 reserve_avail_buf_mergeable(struct virtio_net *dev, struct vhost_virtqueue *vq,
 600                                 uint32_t size, struct buf_vector *buf_vec,
 601                                 uint16_t *num_buffers, uint16_t avail_head)
 602 {
 603         uint16_t cur_idx;
 604         uint32_t vec_idx = 0;
 605         uint16_t tries = 0;
 606
 607         uint16_t head_idx = 0;
 608         uint16_t len = 0;
 609
 610         *num_buffers = 0;
 611         cur_idx  = vq->last_avail_idx;
 612
 613         while (size > 0) {
 614                 if (unlikely(cur_idx == avail_head))
 615                         return -1;
 616
 617                 if (unlikely(fill_vec_buf(dev, vq, cur_idx, &vec_idx, buf_vec,
 618                                                 &head_idx, &len) < 0))
 619                         return -1;
 620                 len = RTE_MIN(len, size);
 621                 update_shadow_used_ring(vq, head_idx, len);
 622                 size -= len;
 623
 624                 cur_idx++;
 625                 tries++;
 626                 *num_buffers += 1;
 627
 628                 /*
 629                  * if we tried all available ring items, and still
 630                  * can't get enough buf, it means something abnormal
 631                  * happened.
 632                  */
 633                 if (unlikely(tries >= vq->size))
 634                         return -1;
 635         }
 636
 637         return 0;
 638 }
 639
 640 static __rte_always_inline int
 641 copy_mbuf_to_desc_mergeable(struct virtio_net *dev, struct vhost_virtqueue *vq,
 642                             struct rte_mbuf *m, struct buf_vector *buf_vec,
 643                             uint16_t num_buffers)
 644 {
 645         uint32_t vec_idx = 0;
 646         uint64_t desc_addr, desc_gaddr;
 647         uint32_t mbuf_offset, mbuf_avail;
 648         uint32_t desc_offset, desc_avail;
 649         uint32_t cpy_len;
 650         uint64_t desc_chunck_len;
 651         uint64_t hdr_addr, hdr_phys_addr;
 652         struct rte_mbuf *hdr_mbuf;
 653         struct batch_copy_elem *batch_copy = vq->batch_copy_elems;
 654         struct virtio_net_hdr_mrg_rxbuf tmp_hdr, *hdr = NULL;
 655         uint16_t copy_nb = vq->batch_copy_nb_elems;
 656         int error = 0;
 657
 658         if (unlikely(m == NULL)) {
 659                 error = -1;
 660                 goto out;
 661         }
 662
 663         desc_chunck_len = buf_vec[vec_idx].buf_len;
 664         desc_gaddr = buf_vec[vec_idx].buf_addr;
 665         desc_addr = vhost_iova_to_vva(dev, vq,
 666                                         desc_gaddr,
 667                                         &desc_chunck_len,
 668                                         VHOST_ACCESS_RW);
 669         if (buf_vec[vec_idx].buf_len < dev->vhost_hlen || !desc_addr) {
 670                 error = -1;
 671                 goto out;
 672         }
 673
 674         hdr_mbuf = m;
 675         hdr_addr = desc_addr;
 676         if (unlikely(desc_chunck_len < dev->vhost_hlen))
 677                 hdr = &tmp_hdr;
 678         else
 679                 hdr = (struct virtio_net_hdr_mrg_rxbuf *)(uintptr_t)hdr_addr;
 680         hdr_phys_addr = desc_gaddr;
 681         rte_prefetch0((void *)(uintptr_t)hdr_addr);
 682
 683         VHOST_LOG_DEBUG(VHOST_DATA, "(%d) RX: num merge buffers %d\n",
 684                 dev->vid, num_buffers);
 685
 686         desc_avail  = buf_vec[vec_idx].buf_len - dev->vhost_hlen;
 687         if (unlikely(desc_chunck_len < dev->vhost_hlen)) {
 688                 desc_chunck_len = desc_avail;
 689                 desc_gaddr += dev->vhost_hlen;
 690                 desc_addr = vhost_iova_to_vva(dev, vq,
 691                                 desc_gaddr,
 692                                 &desc_chunck_len,
 693                                 VHOST_ACCESS_RW);
 694                 if (unlikely(!desc_addr)) {
 695                         error = -1;
 696                         goto out;
 697                 }
 698
 699                 desc_offset = 0;
 700         } else {
 701                 desc_offset = dev->vhost_hlen;
 702                 desc_chunck_len -= dev->vhost_hlen;
 703         }
 704
 705
 706         mbuf_avail  = rte_pktmbuf_data_len(m);
 707         mbuf_offset = 0;
 708         while (mbuf_avail != 0 || m->next != NULL) {
 709                 /* done with current desc buf, get the next one */
 710                 if (desc_avail == 0) {
 711                         vec_idx++;
 712                         desc_chunck_len = buf_vec[vec_idx].buf_len;
 713                         desc_gaddr = buf_vec[vec_idx].buf_addr;
 714                         desc_addr =
 715                                 vhost_iova_to_vva(dev, vq,
 716                                         desc_gaddr,
 717                                         &desc_chunck_len,
 718                                         VHOST_ACCESS_RW);
 719                         if (unlikely(!desc_addr)) {
 720                                 error = -1;
 721                                 goto out;
 722                         }
 723
 724                         /* Prefetch buffer address. */
 725                         rte_prefetch0((void *)(uintptr_t)desc_addr);
 726                         desc_offset = 0;
 727                         desc_avail  = buf_vec[vec_idx].buf_len;
 728                 } else if (unlikely(desc_chunck_len == 0)) {
 729                         desc_chunck_len = desc_avail;
 730                         desc_gaddr += desc_offset;
 731                         desc_addr = vhost_iova_to_vva(dev, vq,
 732                                         desc_gaddr,
 733                                         &desc_chunck_len, VHOST_ACCESS_RW);
 734                         if (unlikely(!desc_addr)) {
 735                                 error = -1;
 736                                 goto out;
 737                         }
 738                         desc_offset = 0;
 739                 }
 740
 741                 /* done with current mbuf, get the next one */
 742                 if (mbuf_avail == 0) {
 743                         m = m->next;
 744
 745                         mbuf_offset = 0;
 746                         mbuf_avail  = rte_pktmbuf_data_len(m);
 747                 }
 748
 749                 if (hdr_addr) {
 750                         virtio_enqueue_offload(hdr_mbuf, &hdr->hdr);
 751                         ASSIGN_UNLESS_EQUAL(hdr->num_buffers, num_buffers);
 752
 753                         if (unlikely(hdr == &tmp_hdr)) {
 754                                 uint64_t len;
 755                                 uint64_t remain = dev->vhost_hlen;
 756                                 uint64_t src = (uint64_t)(uintptr_t)hdr, dst;
 757                                 uint64_t guest_addr = hdr_phys_addr;
 758
 759                                 while (remain) {
 760                                         len = remain;
 761                                         dst = vhost_iova_to_vva(dev, vq,
 762                                                         guest_addr, &len,
 763                                                         VHOST_ACCESS_RW);
 764                                         if (unlikely(!dst || !len)) {
 765                                                 error = -1;
 766                                                 goto out;
 767                                         }
 768
 769                                         rte_memcpy((void *)(uintptr_t)dst,
 770                                                         (void *)(uintptr_t)src,
 771                                                         len);
 772
 773                                         PRINT_PACKET(dev, (uintptr_t)dst,
 774                                                         (uint32_t)len, 0);
 775                                         vhost_log_cache_write(dev, vq,
 776                                                         guest_addr, len);
 777
 778                                         remain -= len;
 779                                         guest_addr += len;
 780                                         src += len;
 781                                 }
 782                         } else {
 783                                 PRINT_PACKET(dev, (uintptr_t)hdr_addr,
 784                                                 dev->vhost_hlen, 0);
 785                                 vhost_log_cache_write(dev, vq, hdr_phys_addr,
 786                                                 dev->vhost_hlen);
 787                         }
 788
 789                         hdr_addr = 0;
 790                 }
 791
 792                 cpy_len = RTE_MIN(desc_chunck_len, mbuf_avail);
 793
 794                 if (likely(cpy_len > MAX_BATCH_LEN || copy_nb >= vq->size)) {
 795                         rte_memcpy((void *)((uintptr_t)(desc_addr +
 796                                                         desc_offset)),
 797                                 rte_pktmbuf_mtod_offset(m, void *, mbuf_offset),
 798                                 cpy_len);
 799                         vhost_log_cache_write(dev, vq, desc_gaddr + desc_offset,
 800                                         cpy_len);
 801                         PRINT_PACKET(dev, (uintptr_t)(desc_addr + desc_offset),
 802                                 cpy_len, 0);
 803                 } else {
 804                         batch_copy[copy_nb].dst =
 805                                 (void *)((uintptr_t)(desc_addr + desc_offset));
 806                         batch_copy[copy_nb].src =
 807                                 rte_pktmbuf_mtod_offset(m, void *, mbuf_offset);
 808                         batch_copy[copy_nb].log_addr = desc_gaddr + desc_offset;
 809                         batch_copy[copy_nb].len = cpy_len;
 810                         copy_nb++;
 811                 }
 812
 813                 mbuf_avail  -= cpy_len;
 814                 mbuf_offset += cpy_len;
 815                 desc_avail  -= cpy_len;
 816                 desc_offset += cpy_len;
 817                 desc_chunck_len -= cpy_len;
 818         }
 819
 820 out:
 821         vq->batch_copy_nb_elems = copy_nb;
 822
 823         return error;
 824 }
 825
 826 static __rte_always_inline uint32_t
 827 virtio_dev_merge_rx(struct virtio_net *dev, uint16_t queue_id,
 828         struct rte_mbuf **pkts, uint32_t count)
 829 {
 830         struct vhost_virtqueue *vq;
 831         uint32_t pkt_idx = 0;
 832         uint16_t num_buffers;
 833         struct buf_vector buf_vec[BUF_VECTOR_MAX];
 834         uint16_t avail_head;
 835
 836         VHOST_LOG_DEBUG(VHOST_DATA, "(%d) %s\n", dev->vid, __func__);
 837         if (unlikely(!is_valid_virt_queue_idx(queue_id, 0, dev->nr_vring))) {
 838                 RTE_LOG(ERR, VHOST_DATA, "(%d) %s: invalid virtqueue idx %d.\n",
 839                         dev->vid, __func__, queue_id);
 840                 return 0;
 841         }
 842
 843         vq = dev->virtqueue[queue_id];
 844
 845         rte_spinlock_lock(&vq->access_lock);
 846
 847         if (unlikely(vq->enabled == 0))
 848                 goto out_access_unlock;
 849
 850         if (dev->features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))
 851                 vhost_user_iotlb_rd_lock(vq);
 852
 853         if (unlikely(vq->access_ok == 0))
 854                 if (unlikely(vring_translate(dev, vq) < 0))
 855                         goto out;
 856
 857         count = RTE_MIN((uint32_t)MAX_PKT_BURST, count);
 858         if (count == 0)
 859                 goto out;
 860
 861         vq->batch_copy_nb_elems = 0;
 862
 863         rte_prefetch0(&vq->avail->ring[vq->last_avail_idx & (vq->size - 1)]);
 864
 865         vq->shadow_used_idx = 0;
 866         avail_head = *((volatile uint16_t *)&vq->avail->idx);
 867         for (pkt_idx = 0; pkt_idx < count; pkt_idx++) {
 868                 uint32_t pkt_len = pkts[pkt_idx]->pkt_len + dev->vhost_hlen;
 869
 870                 if (unlikely(reserve_avail_buf_mergeable(dev, vq,
 871                                                 pkt_len, buf_vec, &num_buffers,
 872                                                 avail_head) < 0)) {
 873                         VHOST_LOG_DEBUG(VHOST_DATA,
 874                                 "(%d) failed to get enough desc from vring\n",
 875                                 dev->vid);
 876                         vq->shadow_used_idx -= num_buffers;
 877                         break;
 878                 }
 879
 880                 VHOST_LOG_DEBUG(VHOST_DATA, "(%d) current index %d | end index %d\n",
 881                         dev->vid, vq->last_avail_idx,
 882                         vq->last_avail_idx + num_buffers);
 883
 884                 if (copy_mbuf_to_desc_mergeable(dev, vq, pkts[pkt_idx],
 885                                                 buf_vec, num_buffers) < 0) {
 886                         vq->shadow_used_idx -= num_buffers;
 887                         break;
 888                 }
 889
 890                 vq->last_avail_idx += num_buffers;
 891         }
 892
 893         do_data_copy_enqueue(dev, vq);
 894
 895         if (likely(vq->shadow_used_idx)) {
 896                 flush_shadow_used_ring(dev, vq);
 897                 vhost_vring_call(dev, vq);
 898         }
 899
 900 out:
 901         if (dev->features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))
 902                 vhost_user_iotlb_rd_unlock(vq);
 903
 904 out_access_unlock:
 905         rte_spinlock_unlock(&vq->access_lock);
 906
 907         return pkt_idx;
 908 }
 909
 910 uint16_t
 911 rte_vhost_enqueue_burst(int vid, uint16_t queue_id,
 912         struct rte_mbuf **pkts, uint16_t count)
 913 {
 914         struct virtio_net *dev = get_device(vid);
 915
 916         if (!dev)
 917                 return 0;
 918
 919         if (unlikely(!(dev->flags & VIRTIO_DEV_BUILTIN_VIRTIO_NET))) {
 920                 RTE_LOG(ERR, VHOST_DATA,
 921                         "(%d) %s: built-in vhost net backend is disabled.\n",
 922                         dev->vid, __func__);
 923                 return 0;
 924         }
 925
 926         if (dev->features & (1 << VIRTIO_NET_F_MRG_RXBUF))
 927                 return virtio_dev_merge_rx(dev, queue_id, pkts, count);
 928         else
 929                 return virtio_dev_rx(dev, queue_id, pkts, count);
 930 }
 931
 932 static inline bool
 933 virtio_net_with_host_offload(struct virtio_net *dev)
 934 {
 935         if (dev->features &
 936                         ((1ULL << VIRTIO_NET_F_CSUM) |
 937                          (1ULL << VIRTIO_NET_F_HOST_ECN) |
 938                          (1ULL << VIRTIO_NET_F_HOST_TSO4) |
 939                          (1ULL << VIRTIO_NET_F_HOST_TSO6) |
 940                          (1ULL << VIRTIO_NET_F_HOST_UFO)))
 941                 return true;
 942
 943         return false;
 944 }
 945
 946 static void
 947 parse_ethernet(struct rte_mbuf *m, uint16_t *l4_proto, void **l4_hdr)
 948 {
 949         struct ipv4_hdr *ipv4_hdr;
 950         struct ipv6_hdr *ipv6_hdr;
 951         void *l3_hdr = NULL;
 952         struct ether_hdr *eth_hdr;
 953         uint16_t ethertype;
 954
 955         eth_hdr = rte_pktmbuf_mtod(m, struct ether_hdr *);
 956
 957         m->l2_len = sizeof(struct ether_hdr);
 958         ethertype = rte_be_to_cpu_16(eth_hdr->ether_type);
 959
 960         if (ethertype == ETHER_TYPE_VLAN) {
 961                 struct vlan_hdr *vlan_hdr = (struct vlan_hdr *)(eth_hdr + 1);
 962
 963                 m->l2_len += sizeof(struct vlan_hdr);
 964                 ethertype = rte_be_to_cpu_16(vlan_hdr->eth_proto);
 965         }
 966
 967         l3_hdr = (char *)eth_hdr + m->l2_len;
 968
 969         switch (ethertype) {
 970         case ETHER_TYPE_IPv4:
 971                 ipv4_hdr = l3_hdr;
 972                 *l4_proto = ipv4_hdr->next_proto_id;
 973                 m->l3_len = (ipv4_hdr->version_ihl & 0x0f) * 4;
 974                 *l4_hdr = (char *)l3_hdr + m->l3_len;
 975                 m->ol_flags |= PKT_TX_IPV4;
 976                 break;
 977         case ETHER_TYPE_IPv6:
 978                 ipv6_hdr = l3_hdr;
 979                 *l4_proto = ipv6_hdr->proto;
 980                 m->l3_len = sizeof(struct ipv6_hdr);
 981                 *l4_hdr = (char *)l3_hdr + m->l3_len;
 982                 m->ol_flags |= PKT_TX_IPV6;
 983                 break;
 984         default:
 985                 m->l3_len = 0;
 986                 *l4_proto = 0;
 987                 *l4_hdr = NULL;
 988                 break;
 989         }
 990 }
 991
 992 static __rte_always_inline void
 993 vhost_dequeue_offload(struct virtio_net_hdr *hdr, struct rte_mbuf *m)
 994 {
 995         uint16_t l4_proto = 0;
 996         void *l4_hdr = NULL;
 997         struct tcp_hdr *tcp_hdr = NULL;
 998
 999         if (hdr->flags == 0 && hdr->gso_type == VIRTIO_NET_HDR_GSO_NONE)
1000                 return;
1001
1002         parse_ethernet(m, &l4_proto, &l4_hdr);
1003         if (hdr->flags == VIRTIO_NET_HDR_F_NEEDS_CSUM) {
1004                 if (hdr->csum_start == (m->l2_len + m->l3_len)) {
1005                         switch (hdr->csum_offset) {
1006                         case (offsetof(struct tcp_hdr, cksum)):
1007                                 if (l4_proto == IPPROTO_TCP)
1008                                         m->ol_flags |= PKT_TX_TCP_CKSUM;
1009                                 break;
1010                         case (offsetof(struct udp_hdr, dgram_cksum)):
1011                                 if (l4_proto == IPPROTO_UDP)
1012                                         m->ol_flags |= PKT_TX_UDP_CKSUM;
1013                                 break;
1014                         case (offsetof(struct sctp_hdr, cksum)):
1015                                 if (l4_proto == IPPROTO_SCTP)
1016                                         m->ol_flags |= PKT_TX_SCTP_CKSUM;
1017                                 break;
1018                         default:
1019                                 break;
1020                         }
1021                 }
1022         }
1023
1024         if (l4_hdr && hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) {
1025                 switch (hdr->gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
1026                 case VIRTIO_NET_HDR_GSO_TCPV4:
1027                 case VIRTIO_NET_HDR_GSO_TCPV6:
1028                         tcp_hdr = l4_hdr;
1029                         m->ol_flags |= PKT_TX_TCP_SEG;
1030                         m->tso_segsz = hdr->gso_size;
1031                         m->l4_len = (tcp_hdr->data_off & 0xf0) >> 2;
1032                         break;
1033                 case VIRTIO_NET_HDR_GSO_UDP:
1034                         m->ol_flags |= PKT_TX_UDP_SEG;
1035                         m->tso_segsz = hdr->gso_size;
1036                         m->l4_len = sizeof(struct udp_hdr);
1037                         break;
1038                 default:
1039                         RTE_LOG(WARNING, VHOST_DATA,
1040                                 "unsupported gso type %u.\n", hdr->gso_type);
1041                         break;
1042                 }
1043         }
1044 }
1045
1046 static __rte_always_inline void
1047 put_zmbuf(struct zcopy_mbuf *zmbuf)
1048 {
1049         zmbuf->in_use = 0;
1050 }
1051
1052 static __rte_always_inline int
1053 copy_desc_to_mbuf(struct virtio_net *dev, struct vhost_virtqueue *vq,
1054                   struct vring_desc *descs, uint16_t max_desc,
1055                   struct rte_mbuf *m, uint16_t desc_idx,
1056                   struct rte_mempool *mbuf_pool)
1057 {
1058         struct vring_desc *desc;
1059         uint64_t desc_addr, desc_gaddr;
1060         uint32_t desc_avail, desc_offset;
1061         uint32_t mbuf_avail, mbuf_offset;
1062         uint32_t cpy_len;
1063         uint64_t desc_chunck_len;
1064         struct rte_mbuf *cur = m, *prev = m;
1065         struct virtio_net_hdr tmp_hdr;
1066         struct virtio_net_hdr *hdr = NULL;
1067         /* A counter to avoid desc dead loop chain */
1068         uint32_t nr_desc = 1;
1069         struct batch_copy_elem *batch_copy = vq->batch_copy_elems;
1070         uint16_t copy_nb = vq->batch_copy_nb_elems;
1071         int error = 0;
1072
1073         desc = &descs[desc_idx];
1074         if (unlikely((desc->len < dev->vhost_hlen)) ||
1075                         (desc->flags & VRING_DESC_F_INDIRECT)) {
1076                 error = -1;
1077                 goto out;
1078         }
1079
1080         desc_chunck_len = desc->len;
1081         desc_gaddr = desc->addr;
1082         desc_addr = vhost_iova_to_vva(dev,
1083                                         vq, desc_gaddr,
1084                                         &desc_chunck_len,
1085                                         VHOST_ACCESS_RO);
1086         if (unlikely(!desc_addr)) {
1087                 error = -1;
1088                 goto out;
1089         }
1090
1091         if (virtio_net_with_host_offload(dev)) {
1092                 if (unlikely(desc_chunck_len < sizeof(struct virtio_net_hdr))) {
1093                         uint64_t len = desc_chunck_len;
1094                         uint64_t remain = sizeof(struct virtio_net_hdr);
1095                         uint64_t src = desc_addr;
1096                         uint64_t dst = (uint64_t)(uintptr_t)&tmp_hdr;
1097                         uint64_t guest_addr = desc_gaddr;
1098
1099                         /*
1100                          * No luck, the virtio-net header doesn't fit
1101                          * in a contiguous virtual area.
1102                          */
1103                         while (remain) {
1104                                 len = remain;
1105                                 src = vhost_iova_to_vva(dev, vq,
1106                                                 guest_addr, &len,
1107                                                 VHOST_ACCESS_RO);
1108                                 if (unlikely(!src || !len)) {
1109                                         error = -1;
1110                                         goto out;
1111                                 }
1112
1113                                 rte_memcpy((void *)(uintptr_t)dst,
1114                                                    (void *)(uintptr_t)src, len);
1115
1116                                 guest_addr += len;
1117                                 remain -= len;
1118                                 dst += len;
1119                         }
1120
1121                         hdr = &tmp_hdr;
1122                 } else {
1123                         hdr = (struct virtio_net_hdr *)((uintptr_t)desc_addr);
1124                         rte_prefetch0(hdr);
1125                 }
1126         }
1127
1128         /*
1129          * A virtio driver normally uses at least 2 desc buffers
1130          * for Tx: the first for storing the header, and others
1131          * for storing the data.
1132          */
1133         if (likely((desc->len == dev->vhost_hlen) &&
1134                    (desc->flags & VRING_DESC_F_NEXT) != 0)) {
1135                 desc = &descs[desc->next];
1136                 if (unlikely(desc->flags & VRING_DESC_F_INDIRECT)) {
1137                         error = -1;
1138                         goto out;
1139                 }
1140
1141                 desc_chunck_len = desc->len;
1142                 desc_gaddr = desc->addr;
1143                 desc_addr = vhost_iova_to_vva(dev,
1144                                                         vq, desc_gaddr,
1145                                                         &desc_chunck_len,
1146                                                         VHOST_ACCESS_RO);
1147                 if (unlikely(!desc_addr)) {
1148                         error = -1;
1149                         goto out;
1150                 }
1151
1152                 desc_offset = 0;
1153                 desc_avail  = desc->len;
1154                 nr_desc    += 1;
1155         } else {
1156                 desc_avail  = desc->len - dev->vhost_hlen;
1157
1158                 if (unlikely(desc_chunck_len < dev->vhost_hlen)) {
1159                         desc_chunck_len = desc_avail;
1160                         desc_gaddr += dev->vhost_hlen;
1161                         desc_addr = vhost_iova_to_vva(dev,
1162                                         vq, desc_gaddr,
1163                                         &desc_chunck_len,
1164                                         VHOST_ACCESS_RO);
1165                         if (unlikely(!desc_addr)) {
1166                                 error = -1;
1167                                 goto out;
1168                         }
1169
1170                         desc_offset = 0;
1171                 } else {
1172                         desc_offset = dev->vhost_hlen;
1173                         desc_chunck_len -= dev->vhost_hlen;
1174                 }
1175         }
1176
1177         rte_prefetch0((void *)(uintptr_t)(desc_addr + desc_offset));
1178
1179         PRINT_PACKET(dev, (uintptr_t)(desc_addr + desc_offset),
1180                         (uint32_t)desc_chunck_len, 0);
1181
1182         mbuf_offset = 0;
1183         mbuf_avail  = m->buf_len - RTE_PKTMBUF_HEADROOM;
1184         while (1) {
1185                 uint64_t hpa;
1186
1187                 cpy_len = RTE_MIN(desc_chunck_len, mbuf_avail);
1188
1189                 /*
1190                  * A desc buf might across two host physical pages that are
1191                  * not continuous. In such case (gpa_to_hpa returns 0), data
1192                  * will be copied even though zero copy is enabled.
1193                  */
1194                 if (unlikely(dev->dequeue_zero_copy && (hpa = gpa_to_hpa(dev,
1195                                         desc_gaddr + desc_offset, cpy_len)))) {
1196                         cur->data_len = cpy_len;
1197                         cur->data_off = 0;
1198                         cur->buf_addr = (void *)(uintptr_t)(desc_addr
1199                                 + desc_offset);
1200                         cur->buf_iova = hpa;
1201
1202                         /*
1203                          * In zero copy mode, one mbuf can only reference data
1204                          * for one or partial of one desc buff.
1205                          */
1206                         mbuf_avail = cpy_len;
1207                 } else {
1208                         if (likely(cpy_len > MAX_BATCH_LEN ||
1209                                    copy_nb >= vq->size ||
1210                                    (hdr && cur == m) ||
1211                                    desc->len != desc_chunck_len)) {
1212                                 rte_memcpy(rte_pktmbuf_mtod_offset(cur, void *,
1213                                                                    mbuf_offset),
1214                                            (void *)((uintptr_t)(desc_addr +
1215                                                                 desc_offset)),
1216                                            cpy_len);
1217                         } else {
1218                                 batch_copy[copy_nb].dst =
1219                                         rte_pktmbuf_mtod_offset(cur, void *,
1220                                                                 mbuf_offset);
1221                                 batch_copy[copy_nb].src =
1222                                         (void *)((uintptr_t)(desc_addr +
1223                                                              desc_offset));
1224                                 batch_copy[copy_nb].len = cpy_len;
1225                                 copy_nb++;
1226                         }
1227                 }
1228
1229                 mbuf_avail  -= cpy_len;
1230                 mbuf_offset += cpy_len;
1231                 desc_avail  -= cpy_len;
1232                 desc_chunck_len -= cpy_len;
1233                 desc_offset += cpy_len;
1234
1235                 /* This desc reaches to its end, get the next one */
1236                 if (desc_avail == 0) {
1237                         if ((desc->flags & VRING_DESC_F_NEXT) == 0)
1238                                 break;
1239
1240                         if (unlikely(desc->next >= max_desc ||
1241                                      ++nr_desc > max_desc)) {
1242                                 error = -1;
1243                                 goto out;
1244                         }
1245                         desc = &descs[desc->next];
1246                         if (unlikely(desc->flags & VRING_DESC_F_INDIRECT)) {
1247                                 error = -1;
1248                                 goto out;
1249                         }
1250
1251                         desc_chunck_len = desc->len;
1252                         desc_gaddr = desc->addr;
1253                         desc_addr = vhost_iova_to_vva(dev,
1254                                                         vq, desc_gaddr,
1255                                                         &desc_chunck_len,
1256                                                         VHOST_ACCESS_RO);
1257                         if (unlikely(!desc_addr)) {
1258                                 error = -1;
1259                                 goto out;
1260                         }
1261
1262                         rte_prefetch0((void *)(uintptr_t)desc_addr);
1263
1264                         desc_offset = 0;
1265                         desc_avail  = desc->len;
1266
1267                         PRINT_PACKET(dev, (uintptr_t)desc_addr,
1268                                         (uint32_t)desc_chunck_len, 0);
1269                 } else if (unlikely(desc_chunck_len == 0)) {
1270                         desc_chunck_len = desc_avail;
1271                         desc_gaddr += desc_offset;
1272                         desc_addr = vhost_iova_to_vva(dev, vq,
1273                                         desc_gaddr,
1274                                         &desc_chunck_len,
1275                                         VHOST_ACCESS_RO);
1276                         if (unlikely(!desc_addr)) {
1277                                 error = -1;
1278                                 goto out;
1279                         }
1280                         desc_offset = 0;
1281
1282                         PRINT_PACKET(dev, (uintptr_t)desc_addr,
1283                                         (uint32_t)desc_chunck_len, 0);
1284                 }
1285
1286                 /*
1287                  * This mbuf reaches to its end, get a new one
1288                  * to hold more data.
1289                  */
1290                 if (mbuf_avail == 0) {
1291                         cur = rte_pktmbuf_alloc(mbuf_pool);
1292                         if (unlikely(cur == NULL)) {
1293                                 RTE_LOG(ERR, VHOST_DATA, "Failed to "
1294                                         "allocate memory for mbuf.\n");
1295                                 error = -1;
1296                                 goto out;
1297                         }
1298                         if (unlikely(dev->dequeue_zero_copy))
1299                                 rte_mbuf_refcnt_update(cur, 1);
1300
1301                         prev->next = cur;
1302                         prev->data_len = mbuf_offset;
1303                         m->nb_segs += 1;
1304                         m->pkt_len += mbuf_offset;
1305                         prev = cur;
1306
1307                         mbuf_offset = 0;
1308                         mbuf_avail  = cur->buf_len - RTE_PKTMBUF_HEADROOM;
1309                 }
1310         }
1311
1312         prev->data_len = mbuf_offset;
1313         m->pkt_len    += mbuf_offset;
1314
1315         if (hdr)
1316                 vhost_dequeue_offload(hdr, m);
1317
1318 out:
1319         vq->batch_copy_nb_elems = copy_nb;
1320
1321         return error;
1322 }
1323
1324 static __rte_always_inline void
1325 update_used_ring(struct virtio_net *dev, struct vhost_virtqueue *vq,
1326                  uint32_t used_idx, uint32_t desc_idx)
1327 {
1328         vq->used->ring[used_idx].id  = desc_idx;
1329         vq->used->ring[used_idx].len = 0;
1330         vhost_log_cache_used_vring(dev, vq,
1331                         offsetof(struct vring_used, ring[used_idx]),
1332                         sizeof(vq->used->ring[used_idx]));
1333 }
1334
1335 static __rte_always_inline void
1336 update_used_idx(struct virtio_net *dev, struct vhost_virtqueue *vq,
1337                 uint32_t count)
1338 {
1339         if (unlikely(count == 0))
1340                 return;
1341
1342         rte_smp_wmb();
1343         rte_smp_rmb();
1344
1345         vhost_log_cache_sync(dev, vq);
1346
1347         vq->used->idx += count;
1348         vhost_log_used_vring(dev, vq, offsetof(struct vring_used, idx),
1349                         sizeof(vq->used->idx));
1350         vhost_vring_call(dev, vq);
1351 }
1352
1353 static __rte_always_inline struct zcopy_mbuf *
1354 get_zmbuf(struct vhost_virtqueue *vq)
1355 {
1356         uint16_t i;
1357         uint16_t last;
1358         int tries = 0;
1359
1360         /* search [last_zmbuf_idx, zmbuf_size) */
1361         i = vq->last_zmbuf_idx;
1362         last = vq->zmbuf_size;
1363
1364 again:
1365         for (; i < last; i++) {
1366                 if (vq->zmbufs[i].in_use == 0) {
1367                         vq->last_zmbuf_idx = i + 1;
1368                         vq->zmbufs[i].in_use = 1;
1369                         return &vq->zmbufs[i];
1370                 }
1371         }
1372
1373         tries++;
1374         if (tries == 1) {
1375                 /* search [0, last_zmbuf_idx) */
1376                 i = 0;
1377                 last = vq->last_zmbuf_idx;
1378                 goto again;
1379         }
1380
1381         return NULL;
1382 }
1383
1384 static __rte_always_inline bool
1385 mbuf_is_consumed(struct rte_mbuf *m)
1386 {
1387         while (m) {
1388                 if (rte_mbuf_refcnt_read(m) > 1)
1389                         return false;
1390                 m = m->next;
1391         }
1392
1393         return true;
1394 }
1395
1396 static __rte_always_inline void
1397 restore_mbuf(struct rte_mbuf *m)
1398 {
1399         uint32_t mbuf_size, priv_size;
1400
1401         while (m) {
1402                 priv_size = rte_pktmbuf_priv_size(m->pool);
1403                 mbuf_size = sizeof(struct rte_mbuf) + priv_size;
1404                 /* start of buffer is after mbuf structure and priv data */
1405
1406                 m->buf_addr = (char *)m + mbuf_size;
1407                 m->buf_iova = rte_mempool_virt2iova(m) + mbuf_size;
1408                 m = m->next;
1409         }
1410 }
1411
1412 uint16_t
1413 rte_vhost_dequeue_burst(int vid, uint16_t queue_id,
1414         struct rte_mempool *mbuf_pool, struct rte_mbuf **pkts, uint16_t count)
1415 {
1416         struct virtio_net *dev;
1417         struct rte_mbuf *rarp_mbuf = NULL;
1418         struct vhost_virtqueue *vq;
1419         uint32_t desc_indexes[MAX_PKT_BURST];
1420         uint32_t used_idx;
1421         uint32_t i = 0;
1422         uint16_t free_entries;
1423         uint16_t avail_idx;
1424
1425         dev = get_device(vid);
1426         if (!dev)
1427                 return 0;
1428
1429         if (unlikely(!(dev->flags & VIRTIO_DEV_BUILTIN_VIRTIO_NET))) {
1430                 RTE_LOG(ERR, VHOST_DATA,
1431                         "(%d) %s: built-in vhost net backend is disabled.\n",
1432                         dev->vid, __func__);
1433                 return 0;
1434         }
1435
1436         if (unlikely(!is_valid_virt_queue_idx(queue_id, 1, dev->nr_vring))) {
1437                 RTE_LOG(ERR, VHOST_DATA, "(%d) %s: invalid virtqueue idx %d.\n",
1438                         dev->vid, __func__, queue_id);
1439                 return 0;
1440         }
1441
1442         vq = dev->virtqueue[queue_id];
1443
1444         if (unlikely(rte_spinlock_trylock(&vq->access_lock) == 0))
1445                 return 0;
1446
1447         if (unlikely(vq->enabled == 0))
1448                 goto out_access_unlock;
1449
1450         vq->batch_copy_nb_elems = 0;
1451
1452         if (dev->features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))
1453                 vhost_user_iotlb_rd_lock(vq);
1454
1455         if (unlikely(vq->access_ok == 0))
1456                 if (unlikely(vring_translate(dev, vq) < 0))
1457                         goto out;
1458
1459         if (unlikely(dev->dequeue_zero_copy)) {
1460                 struct zcopy_mbuf *zmbuf, *next;
1461                 int nr_updated = 0;
1462
1463                 for (zmbuf = TAILQ_FIRST(&vq->zmbuf_list);
1464                      zmbuf != NULL; zmbuf = next) {
1465                         next = TAILQ_NEXT(zmbuf, next);
1466
1467                         if (mbuf_is_consumed(zmbuf->mbuf)) {
1468                                 used_idx = vq->last_used_idx++ & (vq->size - 1);
1469                                 update_used_ring(dev, vq, used_idx,
1470                                                  zmbuf->desc_idx);
1471                                 nr_updated += 1;
1472
1473                                 TAILQ_REMOVE(&vq->zmbuf_list, zmbuf, next);
1474                                 restore_mbuf(zmbuf->mbuf);
1475                                 rte_pktmbuf_free(zmbuf->mbuf);
1476                                 put_zmbuf(zmbuf);
1477                                 vq->nr_zmbuf -= 1;
1478                         }
1479                 }
1480
1481                 update_used_idx(dev, vq, nr_updated);
1482         }
1483
1484         /*
1485          * Construct a RARP broadcast packet, and inject it to the "pkts"
1486          * array, to looks like that guest actually send such packet.
1487          *
1488          * Check user_send_rarp() for more information.
1489          *
1490          * broadcast_rarp shares a cacheline in the virtio_net structure
1491          * with some fields that are accessed during enqueue and
1492          * rte_atomic16_cmpset() causes a write if using cmpxchg. This could
1493          * result in false sharing between enqueue and dequeue.
1494          *
1495          * Prevent unnecessary false sharing by reading broadcast_rarp first
1496          * and only performing cmpset if the read indicates it is likely to
1497          * be set.
1498          */
1499
1500         if (unlikely(rte_atomic16_read(&dev->broadcast_rarp) &&
1501                         rte_atomic16_cmpset((volatile uint16_t *)
1502                                 &dev->broadcast_rarp.cnt, 1, 0))) {
1503
1504                 rarp_mbuf = rte_net_make_rarp_packet(mbuf_pool, &dev->mac);
1505                 if (rarp_mbuf == NULL) {
1506                         RTE_LOG(ERR, VHOST_DATA,
1507                                 "Failed to make RARP packet.\n");
1508                         return 0;
1509                 }
1510                 count -= 1;
1511         }
1512
1513         free_entries = *((volatile uint16_t *)&vq->avail->idx) -
1514                         vq->last_avail_idx;
1515         if (free_entries == 0)
1516                 goto out;
1517
1518         VHOST_LOG_DEBUG(VHOST_DATA, "(%d) %s\n", dev->vid, __func__);
1519
1520         /* Prefetch available and used ring */
1521         avail_idx = vq->last_avail_idx & (vq->size - 1);
1522         used_idx  = vq->last_used_idx  & (vq->size - 1);
1523         rte_prefetch0(&vq->avail->ring[avail_idx]);
1524         rte_prefetch0(&vq->used->ring[used_idx]);
1525
1526         count = RTE_MIN(count, MAX_PKT_BURST);
1527         count = RTE_MIN(count, free_entries);
1528         VHOST_LOG_DEBUG(VHOST_DATA, "(%d) about to dequeue %u buffers\n",
1529                         dev->vid, count);
1530
1531         /* Retrieve all of the head indexes first to avoid caching issues. */
1532         for (i = 0; i < count; i++) {
1533                 avail_idx = (vq->last_avail_idx + i) & (vq->size - 1);
1534                 used_idx  = (vq->last_used_idx  + i) & (vq->size - 1);
1535                 desc_indexes[i] = vq->avail->ring[avail_idx];
1536
1537                 if (likely(dev->dequeue_zero_copy == 0))
1538                         update_used_ring(dev, vq, used_idx, desc_indexes[i]);
1539         }
1540
1541         /* Prefetch descriptor index. */
1542         rte_prefetch0(&vq->desc[desc_indexes[0]]);
1543         for (i = 0; i < count; i++) {
1544                 struct vring_desc *desc, *idesc = NULL;
1545                 uint16_t sz, idx;
1546                 uint64_t dlen;
1547                 int err;
1548
1549                 if (likely(i + 1 < count))
1550                         rte_prefetch0(&vq->desc[desc_indexes[i + 1]]);
1551
1552                 if (vq->desc[desc_indexes[i]].flags & VRING_DESC_F_INDIRECT) {
1553                         dlen = vq->desc[desc_indexes[i]].len;
1554                         desc = (struct vring_desc *)(uintptr_t)
1555                                 vhost_iova_to_vva(dev, vq,
1556                                                 vq->desc[desc_indexes[i]].addr,
1557                                                 &dlen,
1558                                                 VHOST_ACCESS_RO);
1559                         if (unlikely(!desc))
1560                                 break;
1561
1562                         if (unlikely(dlen < vq->desc[desc_indexes[i]].len)) {
1563                                 /*
1564                                  * The indirect desc table is not contiguous
1565                                  * in process VA space, we have to copy it.
1566                                  */
1567                                 idesc = alloc_copy_ind_table(dev, vq,
1568                                                 &vq->desc[desc_indexes[i]]);
1569                                 if (unlikely(!idesc))
1570                                         break;
1571
1572                                 desc = idesc;
1573                         }
1574
1575                         rte_prefetch0(desc);
1576                         sz = vq->desc[desc_indexes[i]].len / sizeof(*desc);
1577                         idx = 0;
1578                 } else {
1579                         desc = vq->desc;
1580                         sz = vq->size;
1581                         idx = desc_indexes[i];
1582                 }
1583
1584                 pkts[i] = rte_pktmbuf_alloc(mbuf_pool);
1585                 if (unlikely(pkts[i] == NULL)) {
1586                         RTE_LOG(ERR, VHOST_DATA,
1587                                 "Failed to allocate memory for mbuf.\n");
1588                         free_ind_table(idesc);
1589                         break;
1590                 }
1591
1592                 err = copy_desc_to_mbuf(dev, vq, desc, sz, pkts[i], idx,
1593                                         mbuf_pool);
1594                 if (unlikely(err)) {
1595                         rte_pktmbuf_free(pkts[i]);
1596                         free_ind_table(idesc);
1597                         break;
1598                 }
1599
1600                 if (unlikely(dev->dequeue_zero_copy)) {
1601                         struct zcopy_mbuf *zmbuf;
1602
1603                         zmbuf = get_zmbuf(vq);
1604                         if (!zmbuf) {
1605                                 rte_pktmbuf_free(pkts[i]);
1606                                 free_ind_table(idesc);
1607                                 break;
1608                         }
1609                         zmbuf->mbuf = pkts[i];
1610                         zmbuf->desc_idx = desc_indexes[i];
1611
1612                         /*
1613                          * Pin lock the mbuf; we will check later to see
1614                          * whether the mbuf is freed (when we are the last
1615                          * user) or not. If that's the case, we then could
1616                          * update the used ring safely.
1617                          */
1618                         rte_mbuf_refcnt_update(pkts[i], 1);
1619
1620                         vq->nr_zmbuf += 1;
1621                         TAILQ_INSERT_TAIL(&vq->zmbuf_list, zmbuf, next);
1622                 }
1623
1624                 if (unlikely(!!idesc))
1625                         free_ind_table(idesc);
1626         }
1627         vq->last_avail_idx += i;
1628
1629         if (likely(dev->dequeue_zero_copy == 0)) {
1630                 do_data_copy_dequeue(vq);
1631                 vq->last_used_idx += i;
1632                 update_used_idx(dev, vq, i);
1633         }
1634
1635 out:
1636         if (dev->features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))
1637                 vhost_user_iotlb_rd_unlock(vq);
1638
1639 out_access_unlock:
1640         rte_spinlock_unlock(&vq->access_lock);
1641
1642         if (unlikely(rarp_mbuf != NULL)) {
1643                 /*
1644                  * Inject it to the head of "pkts" array, so that switch's mac
1645                  * learning table will get updated first.
1646                  */
1647                 memmove(&pkts[1], pkts, i * sizeof(struct rte_mbuf *));
1648                 pkts[0] = rarp_mbuf;
1649                 i += 1;
1650         }
1651
1652         return i;
1653 }