lib/librte_vhost/vhost_rxtx.c

   1 /*-
   2  *   BSD LICENSE
   3  *
   4  *   Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
   5  *   All rights reserved.
   6  *
   7  *   Redistribution and use in source and binary forms, with or without
   8  *   modification, are permitted provided that the following conditions
   9  *   are met:
  10  *
  11  *     * Redistributions of source code must retain the above copyright
  12  *       notice, this list of conditions and the following disclaimer.
  13  *     * Redistributions in binary form must reproduce the above copyright
  14  *       notice, this list of conditions and the following disclaimer in
  15  *       the documentation and/or other materials provided with the
  16  *       distribution.
  17  *     * Neither the name of Intel Corporation nor the names of its
  18  *       contributors may be used to endorse or promote products derived
  19  *       from this software without specific prior written permission.
  20  *
  21  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  22  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  23  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  24  *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  25  *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  26  *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  27  *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  28  *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  29  *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  30  *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  31  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  32  */
  33
  34 #include <stdint.h>
  35 #include <stdbool.h>
  36 #include <linux/virtio_net.h>
  37
  38 #include <rte_mbuf.h>
  39 #include <rte_memcpy.h>
  40 #include <rte_ether.h>
  41 #include <rte_ip.h>
  42 #include <rte_virtio_net.h>
  43 #include <rte_tcp.h>
  44 #include <rte_udp.h>
  45 #include <rte_sctp.h>
  46 #include <rte_arp.h>
  47
  48 #include "vhost-net.h"
  49
  50 #define MAX_PKT_BURST 32
  51 #define VHOST_LOG_PAGE  4096
  52
  53 static inline void __attribute__((always_inline))
  54 vhost_log_page(uint8_t *log_base, uint64_t page)
  55 {
  56         log_base[page / 8] |= 1 << (page % 8);
  57 }
  58
  59 static inline void __attribute__((always_inline))
  60 vhost_log_write(struct virtio_net *dev, uint64_t addr, uint64_t len)
  61 {
  62         uint64_t page;
  63
  64         if (likely(((dev->features & (1ULL << VHOST_F_LOG_ALL)) == 0) ||
  65                    !dev->log_base || !len))
  66                 return;
  67
  68         if (unlikely(dev->log_size <= ((addr + len - 1) / VHOST_LOG_PAGE / 8)))
  69                 return;
  70
  71         /* To make sure guest memory updates are committed before logging */
  72         rte_smp_wmb();
  73
  74         page = addr / VHOST_LOG_PAGE;
  75         while (page * VHOST_LOG_PAGE < addr + len) {
  76                 vhost_log_page((uint8_t *)(uintptr_t)dev->log_base, page);
  77                 page += 1;
  78         }
  79 }
  80
  81 static inline void __attribute__((always_inline))
  82 vhost_log_used_vring(struct virtio_net *dev, struct vhost_virtqueue *vq,
  83                      uint64_t offset, uint64_t len)
  84 {
  85         vhost_log_write(dev, vq->log_guest_addr + offset, len);
  86 }
  87
  88 static bool
  89 is_valid_virt_queue_idx(uint32_t idx, int is_tx, uint32_t qp_nb)
  90 {
  91         return (is_tx ^ (idx & 1)) == 0 && idx < qp_nb * VIRTIO_QNUM;
  92 }
  93
  94 static void
  95 virtio_enqueue_offload(struct rte_mbuf *m_buf, struct virtio_net_hdr *net_hdr)
  96 {
  97         if (m_buf->ol_flags & PKT_TX_L4_MASK) {
  98                 net_hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
  99                 net_hdr->csum_start = m_buf->l2_len + m_buf->l3_len;
 100
 101                 switch (m_buf->ol_flags & PKT_TX_L4_MASK) {
 102                 case PKT_TX_TCP_CKSUM:
 103                         net_hdr->csum_offset = (offsetof(struct tcp_hdr,
 104                                                 cksum));
 105                         break;
 106                 case PKT_TX_UDP_CKSUM:
 107                         net_hdr->csum_offset = (offsetof(struct udp_hdr,
 108                                                 dgram_cksum));
 109                         break;
 110                 case PKT_TX_SCTP_CKSUM:
 111                         net_hdr->csum_offset = (offsetof(struct sctp_hdr,
 112                                                 cksum));
 113                         break;
 114                 }
 115         }
 116
 117         if (m_buf->ol_flags & PKT_TX_TCP_SEG) {
 118                 if (m_buf->ol_flags & PKT_TX_IPV4)
 119                         net_hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
 120                 else
 121                         net_hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
 122                 net_hdr->gso_size = m_buf->tso_segsz;
 123                 net_hdr->hdr_len = m_buf->l2_len + m_buf->l3_len
 124                                         + m_buf->l4_len;
 125         }
 126 }
 127
 128 static inline void
 129 copy_virtio_net_hdr(struct virtio_net *dev, uint64_t desc_addr,
 130                     struct virtio_net_hdr_mrg_rxbuf hdr)
 131 {
 132         if (dev->vhost_hlen == sizeof(struct virtio_net_hdr_mrg_rxbuf))
 133                 *(struct virtio_net_hdr_mrg_rxbuf *)(uintptr_t)desc_addr = hdr;
 134         else
 135                 *(struct virtio_net_hdr *)(uintptr_t)desc_addr = hdr.hdr;
 136 }
 137
 138 static inline int __attribute__((always_inline))
 139 copy_mbuf_to_desc(struct virtio_net *dev, struct vhost_virtqueue *vq,
 140                   struct rte_mbuf *m, uint16_t desc_idx)
 141 {
 142         uint32_t desc_avail, desc_offset;
 143         uint32_t mbuf_avail, mbuf_offset;
 144         uint32_t cpy_len;
 145         struct vring_desc *desc;
 146         uint64_t desc_addr;
 147         struct virtio_net_hdr_mrg_rxbuf virtio_hdr = {{0, 0, 0, 0, 0, 0}, 0};
 148
 149         desc = &vq->desc[desc_idx];
 150         if (unlikely(desc->len < dev->vhost_hlen))
 151                 return -1;
 152
 153         desc_addr = gpa_to_vva(dev, desc->addr);
 154         rte_prefetch0((void *)(uintptr_t)desc_addr);
 155
 156         virtio_enqueue_offload(m, &virtio_hdr.hdr);
 157         copy_virtio_net_hdr(dev, desc_addr, virtio_hdr);
 158         vhost_log_write(dev, desc->addr, dev->vhost_hlen);
 159         PRINT_PACKET(dev, (uintptr_t)desc_addr, dev->vhost_hlen, 0);
 160
 161         desc_offset = dev->vhost_hlen;
 162         desc_avail  = desc->len - dev->vhost_hlen;
 163
 164         mbuf_avail  = rte_pktmbuf_data_len(m);
 165         mbuf_offset = 0;
 166         while (mbuf_avail != 0 || m->next != NULL) {
 167                 /* done with current mbuf, fetch next */
 168                 if (mbuf_avail == 0) {
 169                         m = m->next;
 170
 171                         mbuf_offset = 0;
 172                         mbuf_avail  = rte_pktmbuf_data_len(m);
 173                 }
 174
 175                 /* done with current desc buf, fetch next */
 176                 if (desc_avail == 0) {
 177                         if ((desc->flags & VRING_DESC_F_NEXT) == 0) {
 178                                 /* Room in vring buffer is not enough */
 179                                 return -1;
 180                         }
 181                         if (unlikely(desc->next >= vq->size))
 182                                 return -1;
 183
 184                         desc = &vq->desc[desc->next];
 185                         desc_addr   = gpa_to_vva(dev, desc->addr);
 186                         desc_offset = 0;
 187                         desc_avail  = desc->len;
 188                 }
 189
 190                 cpy_len = RTE_MIN(desc_avail, mbuf_avail);
 191                 rte_memcpy((void *)((uintptr_t)(desc_addr + desc_offset)),
 192                         rte_pktmbuf_mtod_offset(m, void *, mbuf_offset),
 193                         cpy_len);
 194                 vhost_log_write(dev, desc->addr + desc_offset, cpy_len);
 195                 PRINT_PACKET(dev, (uintptr_t)(desc_addr + desc_offset),
 196                              cpy_len, 0);
 197
 198                 mbuf_avail  -= cpy_len;
 199                 mbuf_offset += cpy_len;
 200                 desc_avail  -= cpy_len;
 201                 desc_offset += cpy_len;
 202         }
 203
 204         return 0;
 205 }
 206
 207 /**
 208  * This function adds buffers to the virtio devices RX virtqueue. Buffers can
 209  * be received from the physical port or from another virtio device. A packet
 210  * count is returned to indicate the number of packets that are succesfully
 211  * added to the RX queue. This function works when the mbuf is scattered, but
 212  * it doesn't support the mergeable feature.
 213  */
 214 static inline uint32_t __attribute__((always_inline))
 215 virtio_dev_rx(struct virtio_net *dev, uint16_t queue_id,
 216               struct rte_mbuf **pkts, uint32_t count)
 217 {
 218         struct vhost_virtqueue *vq;
 219         uint16_t avail_idx, free_entries, start_idx;
 220         uint16_t desc_indexes[MAX_PKT_BURST];
 221         uint16_t used_idx;
 222         uint32_t i;
 223
 224         LOG_DEBUG(VHOST_DATA, "(%d) %s\n", dev->vid, __func__);
 225         if (unlikely(!is_valid_virt_queue_idx(queue_id, 0, dev->virt_qp_nb))) {
 226                 RTE_LOG(ERR, VHOST_DATA, "(%d) %s: invalid virtqueue idx %d.\n",
 227                         dev->vid, __func__, queue_id);
 228                 return 0;
 229         }
 230
 231         vq = dev->virtqueue[queue_id];
 232         if (unlikely(vq->enabled == 0))
 233                 return 0;
 234
 235         avail_idx = *((volatile uint16_t *)&vq->avail->idx);
 236         start_idx = vq->last_used_idx;
 237         free_entries = avail_idx - start_idx;
 238         count = RTE_MIN(count, free_entries);
 239         count = RTE_MIN(count, (uint32_t)MAX_PKT_BURST);
 240         if (count == 0)
 241                 return 0;
 242
 243         LOG_DEBUG(VHOST_DATA, "(%d) start_idx %d | end_idx %d\n",
 244                 dev->vid, start_idx, start_idx + count);
 245
 246         /* Retrieve all of the desc indexes first to avoid caching issues. */
 247         rte_prefetch0(&vq->avail->ring[start_idx & (vq->size - 1)]);
 248         for (i = 0; i < count; i++) {
 249                 used_idx = (start_idx + i) & (vq->size - 1);
 250                 desc_indexes[i] = vq->avail->ring[used_idx];
 251                 vq->used->ring[used_idx].id = desc_indexes[i];
 252                 vq->used->ring[used_idx].len = pkts[i]->pkt_len +
 253                                                dev->vhost_hlen;
 254                 vhost_log_used_vring(dev, vq,
 255                         offsetof(struct vring_used, ring[used_idx]),
 256                         sizeof(vq->used->ring[used_idx]));
 257         }
 258
 259         rte_prefetch0(&vq->desc[desc_indexes[0]]);
 260         for (i = 0; i < count; i++) {
 261                 uint16_t desc_idx = desc_indexes[i];
 262                 int err;
 263
 264                 err = copy_mbuf_to_desc(dev, vq, pkts[i], desc_idx);
 265                 if (unlikely(err)) {
 266                         used_idx = (start_idx + i) & (vq->size - 1);
 267                         vq->used->ring[used_idx].len = dev->vhost_hlen;
 268                         vhost_log_used_vring(dev, vq,
 269                                 offsetof(struct vring_used, ring[used_idx]),
 270                                 sizeof(vq->used->ring[used_idx]));
 271                 }
 272
 273                 if (i + 1 < count)
 274                         rte_prefetch0(&vq->desc[desc_indexes[i+1]]);
 275         }
 276
 277         rte_smp_wmb();
 278
 279         *(volatile uint16_t *)&vq->used->idx += count;
 280         vq->last_used_idx += count;
 281         vhost_log_used_vring(dev, vq,
 282                 offsetof(struct vring_used, idx),
 283                 sizeof(vq->used->idx));
 284
 285         /* flush used->idx update before we read avail->flags. */
 286         rte_mb();
 287
 288         /* Kick the guest if necessary. */
 289         if (!(vq->avail->flags & VRING_AVAIL_F_NO_INTERRUPT)
 290                         && (vq->callfd >= 0))
 291                 eventfd_write(vq->callfd, (eventfd_t)1);
 292         return count;
 293 }
 294
 295 static inline int
 296 fill_vec_buf(struct vhost_virtqueue *vq, uint32_t avail_idx,
 297              uint32_t *allocated, uint32_t *vec_idx,
 298              struct buf_vector *buf_vec)
 299 {
 300         uint16_t idx = vq->avail->ring[avail_idx & (vq->size - 1)];
 301         uint32_t vec_id = *vec_idx;
 302         uint32_t len    = *allocated;
 303
 304         while (1) {
 305                 if (unlikely(vec_id >= BUF_VECTOR_MAX || idx >= vq->size))
 306                         return -1;
 307
 308                 len += vq->desc[idx].len;
 309                 buf_vec[vec_id].buf_addr = vq->desc[idx].addr;
 310                 buf_vec[vec_id].buf_len  = vq->desc[idx].len;
 311                 buf_vec[vec_id].desc_idx = idx;
 312                 vec_id++;
 313
 314                 if ((vq->desc[idx].flags & VRING_DESC_F_NEXT) == 0)
 315                         break;
 316
 317                 idx = vq->desc[idx].next;
 318         }
 319
 320         *allocated = len;
 321         *vec_idx   = vec_id;
 322
 323         return 0;
 324 }
 325
 326 /*
 327  * Returns -1 on fail, 0 on success
 328  */
 329 static inline int
 330 reserve_avail_buf_mergeable(struct vhost_virtqueue *vq, uint32_t size,
 331                             uint16_t *end, struct buf_vector *buf_vec)
 332 {
 333         uint16_t cur_idx;
 334         uint16_t avail_idx;
 335         uint32_t allocated = 0;
 336         uint32_t vec_idx = 0;
 337         uint16_t tries = 0;
 338
 339         cur_idx  = vq->last_used_idx;
 340
 341         while (1) {
 342                 avail_idx = *((volatile uint16_t *)&vq->avail->idx);
 343                 if (unlikely(cur_idx == avail_idx))
 344                         return -1;
 345
 346                 if (unlikely(fill_vec_buf(vq, cur_idx, &allocated,
 347                                           &vec_idx, buf_vec) < 0))
 348                         return -1;
 349
 350                 cur_idx++;
 351                 tries++;
 352
 353                 if (allocated >= size)
 354                         break;
 355
 356                 /*
 357                  * if we tried all available ring items, and still
 358                  * can't get enough buf, it means something abnormal
 359                  * happened.
 360                  */
 361                 if (unlikely(tries >= vq->size))
 362                         return -1;
 363         }
 364
 365         *end = cur_idx;
 366         return 0;
 367 }
 368
 369 static inline uint32_t __attribute__((always_inline))
 370 copy_mbuf_to_desc_mergeable(struct virtio_net *dev, struct vhost_virtqueue *vq,
 371                             uint16_t end_idx, struct rte_mbuf *m,
 372                             struct buf_vector *buf_vec)
 373 {
 374         struct virtio_net_hdr_mrg_rxbuf virtio_hdr = {{0, 0, 0, 0, 0, 0}, 0};
 375         uint32_t vec_idx = 0;
 376         uint16_t start_idx = vq->last_used_idx;
 377         uint16_t cur_idx = start_idx;
 378         uint64_t desc_addr;
 379         uint32_t mbuf_offset, mbuf_avail;
 380         uint32_t desc_offset, desc_avail;
 381         uint32_t cpy_len;
 382         uint16_t desc_idx, used_idx;
 383
 384         if (unlikely(m == NULL))
 385                 return 0;
 386
 387         LOG_DEBUG(VHOST_DATA, "(%d) current index %d | end index %d\n",
 388                 dev->vid, cur_idx, end_idx);
 389
 390         if (buf_vec[vec_idx].buf_len < dev->vhost_hlen)
 391                 return -1;
 392
 393         desc_addr = gpa_to_vva(dev, buf_vec[vec_idx].buf_addr);
 394         rte_prefetch0((void *)(uintptr_t)desc_addr);
 395
 396         virtio_hdr.num_buffers = end_idx - start_idx;
 397         LOG_DEBUG(VHOST_DATA, "(%d) RX: num merge buffers %d\n",
 398                 dev->vid, virtio_hdr.num_buffers);
 399
 400         virtio_enqueue_offload(m, &virtio_hdr.hdr);
 401         copy_virtio_net_hdr(dev, desc_addr, virtio_hdr);
 402         vhost_log_write(dev, buf_vec[vec_idx].buf_addr, dev->vhost_hlen);
 403         PRINT_PACKET(dev, (uintptr_t)desc_addr, dev->vhost_hlen, 0);
 404
 405         desc_avail  = buf_vec[vec_idx].buf_len - dev->vhost_hlen;
 406         desc_offset = dev->vhost_hlen;
 407
 408         mbuf_avail  = rte_pktmbuf_data_len(m);
 409         mbuf_offset = 0;
 410         while (mbuf_avail != 0 || m->next != NULL) {
 411                 /* done with current desc buf, get the next one */
 412                 if (desc_avail == 0) {
 413                         desc_idx = buf_vec[vec_idx].desc_idx;
 414
 415                         if (!(vq->desc[desc_idx].flags & VRING_DESC_F_NEXT)) {
 416                                 /* Update used ring with desc information */
 417                                 used_idx = cur_idx++ & (vq->size - 1);
 418                                 vq->used->ring[used_idx].id  = desc_idx;
 419                                 vq->used->ring[used_idx].len = desc_offset;
 420                                 vhost_log_used_vring(dev, vq,
 421                                         offsetof(struct vring_used,
 422                                                  ring[used_idx]),
 423                                         sizeof(vq->used->ring[used_idx]));
 424                         }
 425
 426                         vec_idx++;
 427                         desc_addr = gpa_to_vva(dev, buf_vec[vec_idx].buf_addr);
 428
 429                         /* Prefetch buffer address. */
 430                         rte_prefetch0((void *)(uintptr_t)desc_addr);
 431                         desc_offset = 0;
 432                         desc_avail  = buf_vec[vec_idx].buf_len;
 433                 }
 434
 435                 /* done with current mbuf, get the next one */
 436                 if (mbuf_avail == 0) {
 437                         m = m->next;
 438
 439                         mbuf_offset = 0;
 440                         mbuf_avail  = rte_pktmbuf_data_len(m);
 441                 }
 442
 443                 cpy_len = RTE_MIN(desc_avail, mbuf_avail);
 444                 rte_memcpy((void *)((uintptr_t)(desc_addr + desc_offset)),
 445                         rte_pktmbuf_mtod_offset(m, void *, mbuf_offset),
 446                         cpy_len);
 447                 vhost_log_write(dev, buf_vec[vec_idx].buf_addr + desc_offset,
 448                         cpy_len);
 449                 PRINT_PACKET(dev, (uintptr_t)(desc_addr + desc_offset),
 450                         cpy_len, 0);
 451
 452                 mbuf_avail  -= cpy_len;
 453                 mbuf_offset += cpy_len;
 454                 desc_avail  -= cpy_len;
 455                 desc_offset += cpy_len;
 456         }
 457
 458         used_idx = cur_idx & (vq->size - 1);
 459         vq->used->ring[used_idx].id = buf_vec[vec_idx].desc_idx;
 460         vq->used->ring[used_idx].len = desc_offset;
 461         vhost_log_used_vring(dev, vq,
 462                 offsetof(struct vring_used, ring[used_idx]),
 463                 sizeof(vq->used->ring[used_idx]));
 464
 465         return end_idx - start_idx;
 466 }
 467
 468 static inline uint32_t __attribute__((always_inline))
 469 virtio_dev_merge_rx(struct virtio_net *dev, uint16_t queue_id,
 470         struct rte_mbuf **pkts, uint32_t count)
 471 {
 472         struct vhost_virtqueue *vq;
 473         uint32_t pkt_idx = 0, nr_used = 0;
 474         uint16_t end;
 475         struct buf_vector buf_vec[BUF_VECTOR_MAX];
 476
 477         LOG_DEBUG(VHOST_DATA, "(%d) %s\n", dev->vid, __func__);
 478         if (unlikely(!is_valid_virt_queue_idx(queue_id, 0, dev->virt_qp_nb))) {
 479                 RTE_LOG(ERR, VHOST_DATA, "(%d) %s: invalid virtqueue idx %d.\n",
 480                         dev->vid, __func__, queue_id);
 481                 return 0;
 482         }
 483
 484         vq = dev->virtqueue[queue_id];
 485         if (unlikely(vq->enabled == 0))
 486                 return 0;
 487
 488         count = RTE_MIN((uint32_t)MAX_PKT_BURST, count);
 489         if (count == 0)
 490                 return 0;
 491
 492         for (pkt_idx = 0; pkt_idx < count; pkt_idx++) {
 493                 uint32_t pkt_len = pkts[pkt_idx]->pkt_len + dev->vhost_hlen;
 494
 495                 if (unlikely(reserve_avail_buf_mergeable(vq, pkt_len,
 496                                                          &end, buf_vec) < 0)) {
 497                         LOG_DEBUG(VHOST_DATA,
 498                                 "(%d) failed to get enough desc from vring\n",
 499                                 dev->vid);
 500                         break;
 501                 }
 502
 503                 nr_used = copy_mbuf_to_desc_mergeable(dev, vq, end,
 504                                                       pkts[pkt_idx], buf_vec);
 505                 rte_smp_wmb();
 506
 507                 *(volatile uint16_t *)&vq->used->idx += nr_used;
 508                 vhost_log_used_vring(dev, vq, offsetof(struct vring_used, idx),
 509                         sizeof(vq->used->idx));
 510                 vq->last_used_idx = end;
 511         }
 512
 513         if (likely(pkt_idx)) {
 514                 /* flush used->idx update before we read avail->flags. */
 515                 rte_mb();
 516
 517                 /* Kick the guest if necessary. */
 518                 if (!(vq->avail->flags & VRING_AVAIL_F_NO_INTERRUPT)
 519                                 && (vq->callfd >= 0))
 520                         eventfd_write(vq->callfd, (eventfd_t)1);
 521         }
 522
 523         return pkt_idx;
 524 }
 525
 526 uint16_t
 527 rte_vhost_enqueue_burst(int vid, uint16_t queue_id,
 528         struct rte_mbuf **pkts, uint16_t count)
 529 {
 530         struct virtio_net *dev = get_device(vid);
 531
 532         if (!dev)
 533                 return 0;
 534
 535         if (dev->features & (1 << VIRTIO_NET_F_MRG_RXBUF))
 536                 return virtio_dev_merge_rx(dev, queue_id, pkts, count);
 537         else
 538                 return virtio_dev_rx(dev, queue_id, pkts, count);
 539 }
 540
 541 static void
 542 parse_ethernet(struct rte_mbuf *m, uint16_t *l4_proto, void **l4_hdr)
 543 {
 544         struct ipv4_hdr *ipv4_hdr;
 545         struct ipv6_hdr *ipv6_hdr;
 546         void *l3_hdr = NULL;
 547         struct ether_hdr *eth_hdr;
 548         uint16_t ethertype;
 549
 550         eth_hdr = rte_pktmbuf_mtod(m, struct ether_hdr *);
 551
 552         m->l2_len = sizeof(struct ether_hdr);
 553         ethertype = rte_be_to_cpu_16(eth_hdr->ether_type);
 554
 555         if (ethertype == ETHER_TYPE_VLAN) {
 556                 struct vlan_hdr *vlan_hdr = (struct vlan_hdr *)(eth_hdr + 1);
 557
 558                 m->l2_len += sizeof(struct vlan_hdr);
 559                 ethertype = rte_be_to_cpu_16(vlan_hdr->eth_proto);
 560         }
 561
 562         l3_hdr = (char *)eth_hdr + m->l2_len;
 563
 564         switch (ethertype) {
 565         case ETHER_TYPE_IPv4:
 566                 ipv4_hdr = (struct ipv4_hdr *)l3_hdr;
 567                 *l4_proto = ipv4_hdr->next_proto_id;
 568                 m->l3_len = (ipv4_hdr->version_ihl & 0x0f) * 4;
 569                 *l4_hdr = (char *)l3_hdr + m->l3_len;
 570                 m->ol_flags |= PKT_TX_IPV4;
 571                 break;
 572         case ETHER_TYPE_IPv6:
 573                 ipv6_hdr = (struct ipv6_hdr *)l3_hdr;
 574                 *l4_proto = ipv6_hdr->proto;
 575                 m->l3_len = sizeof(struct ipv6_hdr);
 576                 *l4_hdr = (char *)l3_hdr + m->l3_len;
 577                 m->ol_flags |= PKT_TX_IPV6;
 578                 break;
 579         default:
 580                 m->l3_len = 0;
 581                 *l4_proto = 0;
 582                 break;
 583         }
 584 }
 585
 586 static inline void __attribute__((always_inline))
 587 vhost_dequeue_offload(struct virtio_net_hdr *hdr, struct rte_mbuf *m)
 588 {
 589         uint16_t l4_proto = 0;
 590         void *l4_hdr = NULL;
 591         struct tcp_hdr *tcp_hdr = NULL;
 592
 593         parse_ethernet(m, &l4_proto, &l4_hdr);
 594         if (hdr->flags == VIRTIO_NET_HDR_F_NEEDS_CSUM) {
 595                 if (hdr->csum_start == (m->l2_len + m->l3_len)) {
 596                         switch (hdr->csum_offset) {
 597                         case (offsetof(struct tcp_hdr, cksum)):
 598                                 if (l4_proto == IPPROTO_TCP)
 599                                         m->ol_flags |= PKT_TX_TCP_CKSUM;
 600                                 break;
 601                         case (offsetof(struct udp_hdr, dgram_cksum)):
 602                                 if (l4_proto == IPPROTO_UDP)
 603                                         m->ol_flags |= PKT_TX_UDP_CKSUM;
 604                                 break;
 605                         case (offsetof(struct sctp_hdr, cksum)):
 606                                 if (l4_proto == IPPROTO_SCTP)
 607                                         m->ol_flags |= PKT_TX_SCTP_CKSUM;
 608                                 break;
 609                         default:
 610                                 break;
 611                         }
 612                 }
 613         }
 614
 615         if (hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) {
 616                 switch (hdr->gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
 617                 case VIRTIO_NET_HDR_GSO_TCPV4:
 618                 case VIRTIO_NET_HDR_GSO_TCPV6:
 619                         tcp_hdr = (struct tcp_hdr *)l4_hdr;
 620                         m->ol_flags |= PKT_TX_TCP_SEG;
 621                         m->tso_segsz = hdr->gso_size;
 622                         m->l4_len = (tcp_hdr->data_off & 0xf0) >> 2;
 623                         break;
 624                 default:
 625                         RTE_LOG(WARNING, VHOST_DATA,
 626                                 "unsupported gso type %u.\n", hdr->gso_type);
 627                         break;
 628                 }
 629         }
 630 }
 631
 632 #define RARP_PKT_SIZE   64
 633
 634 static int
 635 make_rarp_packet(struct rte_mbuf *rarp_mbuf, const struct ether_addr *mac)
 636 {
 637         struct ether_hdr *eth_hdr;
 638         struct arp_hdr  *rarp;
 639
 640         if (rarp_mbuf->buf_len < 64) {
 641                 RTE_LOG(WARNING, VHOST_DATA,
 642                         "failed to make RARP; mbuf size too small %u (< %d)\n",
 643                         rarp_mbuf->buf_len, RARP_PKT_SIZE);
 644                 return -1;
 645         }
 646
 647         /* Ethernet header. */
 648         eth_hdr = rte_pktmbuf_mtod_offset(rarp_mbuf, struct ether_hdr *, 0);
 649         memset(eth_hdr->d_addr.addr_bytes, 0xff, ETHER_ADDR_LEN);
 650         ether_addr_copy(mac, &eth_hdr->s_addr);
 651         eth_hdr->ether_type = htons(ETHER_TYPE_RARP);
 652
 653         /* RARP header. */
 654         rarp = (struct arp_hdr *)(eth_hdr + 1);
 655         rarp->arp_hrd = htons(ARP_HRD_ETHER);
 656         rarp->arp_pro = htons(ETHER_TYPE_IPv4);
 657         rarp->arp_hln = ETHER_ADDR_LEN;
 658         rarp->arp_pln = 4;
 659         rarp->arp_op  = htons(ARP_OP_REVREQUEST);
 660
 661         ether_addr_copy(mac, &rarp->arp_data.arp_sha);
 662         ether_addr_copy(mac, &rarp->arp_data.arp_tha);
 663         memset(&rarp->arp_data.arp_sip, 0x00, 4);
 664         memset(&rarp->arp_data.arp_tip, 0x00, 4);
 665
 666         rarp_mbuf->pkt_len  = rarp_mbuf->data_len = RARP_PKT_SIZE;
 667
 668         return 0;
 669 }
 670
 671 static inline int __attribute__((always_inline))
 672 copy_desc_to_mbuf(struct virtio_net *dev, struct vhost_virtqueue *vq,
 673                   struct rte_mbuf *m, uint16_t desc_idx,
 674                   struct rte_mempool *mbuf_pool)
 675 {
 676         struct vring_desc *desc;
 677         uint64_t desc_addr;
 678         uint32_t desc_avail, desc_offset;
 679         uint32_t mbuf_avail, mbuf_offset;
 680         uint32_t cpy_len;
 681         struct rte_mbuf *cur = m, *prev = m;
 682         struct virtio_net_hdr *hdr;
 683         /* A counter to avoid desc dead loop chain */
 684         uint32_t nr_desc = 1;
 685
 686         desc = &vq->desc[desc_idx];
 687         if (unlikely(desc->len < dev->vhost_hlen))
 688                 return -1;
 689
 690         desc_addr = gpa_to_vva(dev, desc->addr);
 691         hdr = (struct virtio_net_hdr *)((uintptr_t)desc_addr);
 692         rte_prefetch0(hdr);
 693
 694         /*
 695          * A virtio driver normally uses at least 2 desc buffers
 696          * for Tx: the first for storing the header, and others
 697          * for storing the data.
 698          */
 699         if (likely((desc->len == dev->vhost_hlen) &&
 700                    (desc->flags & VRING_DESC_F_NEXT) != 0)) {
 701                 desc = &vq->desc[desc->next];
 702
 703                 desc_addr = gpa_to_vva(dev, desc->addr);
 704                 rte_prefetch0((void *)(uintptr_t)desc_addr);
 705
 706                 desc_offset = 0;
 707                 desc_avail  = desc->len;
 708                 nr_desc    += 1;
 709
 710                 PRINT_PACKET(dev, (uintptr_t)desc_addr, desc->len, 0);
 711         } else {
 712                 desc_avail  = desc->len - dev->vhost_hlen;
 713                 desc_offset = dev->vhost_hlen;
 714         }
 715
 716         mbuf_offset = 0;
 717         mbuf_avail  = m->buf_len - RTE_PKTMBUF_HEADROOM;
 718         while (1) {
 719                 cpy_len = RTE_MIN(desc_avail, mbuf_avail);
 720                 rte_memcpy(rte_pktmbuf_mtod_offset(cur, void *, mbuf_offset),
 721                         (void *)((uintptr_t)(desc_addr + desc_offset)),
 722                         cpy_len);
 723
 724                 mbuf_avail  -= cpy_len;
 725                 mbuf_offset += cpy_len;
 726                 desc_avail  -= cpy_len;
 727                 desc_offset += cpy_len;
 728
 729                 /* This desc reaches to its end, get the next one */
 730                 if (desc_avail == 0) {
 731                         if ((desc->flags & VRING_DESC_F_NEXT) == 0)
 732                                 break;
 733
 734                         if (unlikely(desc->next >= vq->size ||
 735                                      ++nr_desc >= vq->size))
 736                                 return -1;
 737                         desc = &vq->desc[desc->next];
 738
 739                         desc_addr = gpa_to_vva(dev, desc->addr);
 740                         rte_prefetch0((void *)(uintptr_t)desc_addr);
 741
 742                         desc_offset = 0;
 743                         desc_avail  = desc->len;
 744
 745                         PRINT_PACKET(dev, (uintptr_t)desc_addr, desc->len, 0);
 746                 }
 747
 748                 /*
 749                  * This mbuf reaches to its end, get a new one
 750                  * to hold more data.
 751                  */
 752                 if (mbuf_avail == 0) {
 753                         cur = rte_pktmbuf_alloc(mbuf_pool);
 754                         if (unlikely(cur == NULL)) {
 755                                 RTE_LOG(ERR, VHOST_DATA, "Failed to "
 756                                         "allocate memory for mbuf.\n");
 757                                 return -1;
 758                         }
 759
 760                         prev->next = cur;
 761                         prev->data_len = mbuf_offset;
 762                         m->nb_segs += 1;
 763                         m->pkt_len += mbuf_offset;
 764                         prev = cur;
 765
 766                         mbuf_offset = 0;
 767                         mbuf_avail  = cur->buf_len - RTE_PKTMBUF_HEADROOM;
 768                 }
 769         }
 770
 771         prev->data_len = mbuf_offset;
 772         m->pkt_len    += mbuf_offset;
 773
 774         if (hdr->flags != 0 || hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE)
 775                 vhost_dequeue_offload(hdr, m);
 776
 777         return 0;
 778 }
 779
 780 uint16_t
 781 rte_vhost_dequeue_burst(int vid, uint16_t queue_id,
 782         struct rte_mempool *mbuf_pool, struct rte_mbuf **pkts, uint16_t count)
 783 {
 784         struct virtio_net *dev;
 785         struct rte_mbuf *rarp_mbuf = NULL;
 786         struct vhost_virtqueue *vq;
 787         uint32_t desc_indexes[MAX_PKT_BURST];
 788         uint32_t used_idx;
 789         uint32_t i = 0;
 790         uint16_t free_entries;
 791         uint16_t avail_idx;
 792
 793         dev = get_device(vid);
 794         if (!dev)
 795                 return 0;
 796
 797         if (unlikely(!is_valid_virt_queue_idx(queue_id, 1, dev->virt_qp_nb))) {
 798                 RTE_LOG(ERR, VHOST_DATA, "(%d) %s: invalid virtqueue idx %d.\n",
 799                         dev->vid, __func__, queue_id);
 800                 return 0;
 801         }
 802
 803         vq = dev->virtqueue[queue_id];
 804         if (unlikely(vq->enabled == 0))
 805                 return 0;
 806
 807         /*
 808          * Construct a RARP broadcast packet, and inject it to the "pkts"
 809          * array, to looks like that guest actually send such packet.
 810          *
 811          * Check user_send_rarp() for more information.
 812          */
 813         if (unlikely(rte_atomic16_cmpset((volatile uint16_t *)
 814                                          &dev->broadcast_rarp.cnt, 1, 0))) {
 815                 rarp_mbuf = rte_pktmbuf_alloc(mbuf_pool);
 816                 if (rarp_mbuf == NULL) {
 817                         RTE_LOG(ERR, VHOST_DATA,
 818                                 "Failed to allocate memory for mbuf.\n");
 819                         return 0;
 820                 }
 821
 822                 if (make_rarp_packet(rarp_mbuf, &dev->mac)) {
 823                         rte_pktmbuf_free(rarp_mbuf);
 824                         rarp_mbuf = NULL;
 825                 } else {
 826                         count -= 1;
 827                 }
 828         }
 829
 830         avail_idx =  *((volatile uint16_t *)&vq->avail->idx);
 831         free_entries = avail_idx - vq->last_used_idx;
 832         if (free_entries == 0)
 833                 goto out;
 834
 835         LOG_DEBUG(VHOST_DATA, "(%d) %s\n", dev->vid, __func__);
 836
 837         /* Prefetch available ring to retrieve head indexes. */
 838         used_idx = vq->last_used_idx & (vq->size - 1);
 839         rte_prefetch0(&vq->avail->ring[used_idx]);
 840         rte_prefetch0(&vq->used->ring[used_idx]);
 841
 842         count = RTE_MIN(count, MAX_PKT_BURST);
 843         count = RTE_MIN(count, free_entries);
 844         LOG_DEBUG(VHOST_DATA, "(%d) about to dequeue %u buffers\n",
 845                         dev->vid, count);
 846
 847         /* Retrieve all of the head indexes first to avoid caching issues. */
 848         for (i = 0; i < count; i++) {
 849                 used_idx = (vq->last_used_idx + i) & (vq->size - 1);
 850                 desc_indexes[i] = vq->avail->ring[used_idx];
 851
 852                 vq->used->ring[used_idx].id  = desc_indexes[i];
 853                 vq->used->ring[used_idx].len = 0;
 854                 vhost_log_used_vring(dev, vq,
 855                                 offsetof(struct vring_used, ring[used_idx]),
 856                                 sizeof(vq->used->ring[used_idx]));
 857         }
 858
 859         /* Prefetch descriptor index. */
 860         rte_prefetch0(&vq->desc[desc_indexes[0]]);
 861         for (i = 0; i < count; i++) {
 862                 int err;
 863
 864                 if (likely(i + 1 < count))
 865                         rte_prefetch0(&vq->desc[desc_indexes[i + 1]]);
 866
 867                 pkts[i] = rte_pktmbuf_alloc(mbuf_pool);
 868                 if (unlikely(pkts[i] == NULL)) {
 869                         RTE_LOG(ERR, VHOST_DATA,
 870                                 "Failed to allocate memory for mbuf.\n");
 871                         break;
 872                 }
 873                 err = copy_desc_to_mbuf(dev, vq, pkts[i], desc_indexes[i],
 874                                         mbuf_pool);
 875                 if (unlikely(err)) {
 876                         rte_pktmbuf_free(pkts[i]);
 877                         break;
 878                 }
 879         }
 880
 881         rte_smp_wmb();
 882         rte_smp_rmb();
 883         vq->used->idx += i;
 884         vq->last_used_idx += i;
 885         vhost_log_used_vring(dev, vq, offsetof(struct vring_used, idx),
 886                         sizeof(vq->used->idx));
 887
 888         /* Kick guest if required. */
 889         if (!(vq->avail->flags & VRING_AVAIL_F_NO_INTERRUPT)
 890                         && (vq->callfd >= 0))
 891                 eventfd_write(vq->callfd, (eventfd_t)1);
 892
 893 out:
 894         if (unlikely(rarp_mbuf != NULL)) {
 895                 /*
 896                  * Inject it to the head of "pkts" array, so that switch's mac
 897                  * learning table will get updated first.
 898                  */
 899                 memmove(&pkts[1], pkts, i * sizeof(struct rte_mbuf *));
 900                 pkts[0] = rarp_mbuf;
 901                 i += 1;
 902         }
 903
 904         return i;
 905 }