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         desc_addr = gpa_to_vva(dev, desc->addr);
 151         /*
 152          * Checking of 'desc_addr' placed outside of 'unlikely' macro to avoid
 153          * performance issue with some versions of gcc (4.8.4 and 5.3.0) which
 154          * otherwise stores offset on the stack instead of in a register.
 155          */
 156         if (unlikely(desc->len < dev->vhost_hlen) || !desc_addr)
 157                 return -1;
 158
 159         rte_prefetch0((void *)(uintptr_t)desc_addr);
 160
 161         virtio_enqueue_offload(m, &virtio_hdr.hdr);
 162         copy_virtio_net_hdr(dev, desc_addr, virtio_hdr);
 163         vhost_log_write(dev, desc->addr, dev->vhost_hlen);
 164         PRINT_PACKET(dev, (uintptr_t)desc_addr, dev->vhost_hlen, 0);
 165
 166         desc_offset = dev->vhost_hlen;
 167         desc_avail  = desc->len - dev->vhost_hlen;
 168
 169         mbuf_avail  = rte_pktmbuf_data_len(m);
 170         mbuf_offset = 0;
 171         while (mbuf_avail != 0 || m->next != NULL) {
 172                 /* done with current mbuf, fetch next */
 173                 if (mbuf_avail == 0) {
 174                         m = m->next;
 175
 176                         mbuf_offset = 0;
 177                         mbuf_avail  = rte_pktmbuf_data_len(m);
 178                 }
 179
 180                 /* done with current desc buf, fetch next */
 181                 if (desc_avail == 0) {
 182                         if ((desc->flags & VRING_DESC_F_NEXT) == 0) {
 183                                 /* Room in vring buffer is not enough */
 184                                 return -1;
 185                         }
 186                         if (unlikely(desc->next >= vq->size))
 187                                 return -1;
 188
 189                         desc = &vq->desc[desc->next];
 190                         desc_addr = gpa_to_vva(dev, desc->addr);
 191                         if (unlikely(!desc_addr))
 192                                 return -1;
 193
 194                         desc_offset = 0;
 195                         desc_avail  = desc->len;
 196                 }
 197
 198                 cpy_len = RTE_MIN(desc_avail, mbuf_avail);
 199                 rte_memcpy((void *)((uintptr_t)(desc_addr + desc_offset)),
 200                         rte_pktmbuf_mtod_offset(m, void *, mbuf_offset),
 201                         cpy_len);
 202                 vhost_log_write(dev, desc->addr + desc_offset, cpy_len);
 203                 PRINT_PACKET(dev, (uintptr_t)(desc_addr + desc_offset),
 204                              cpy_len, 0);
 205
 206                 mbuf_avail  -= cpy_len;
 207                 mbuf_offset += cpy_len;
 208                 desc_avail  -= cpy_len;
 209                 desc_offset += cpy_len;
 210         }
 211
 212         return 0;
 213 }
 214
 215 /**
 216  * This function adds buffers to the virtio devices RX virtqueue. Buffers can
 217  * be received from the physical port or from another virtio device. A packet
 218  * count is returned to indicate the number of packets that are succesfully
 219  * added to the RX queue. This function works when the mbuf is scattered, but
 220  * it doesn't support the mergeable feature.
 221  */
 222 static inline uint32_t __attribute__((always_inline))
 223 virtio_dev_rx(struct virtio_net *dev, uint16_t queue_id,
 224               struct rte_mbuf **pkts, uint32_t count)
 225 {
 226         struct vhost_virtqueue *vq;
 227         uint16_t avail_idx, free_entries, start_idx;
 228         uint16_t desc_indexes[MAX_PKT_BURST];
 229         uint16_t used_idx;
 230         uint32_t i;
 231
 232         LOG_DEBUG(VHOST_DATA, "(%d) %s\n", dev->vid, __func__);
 233         if (unlikely(!is_valid_virt_queue_idx(queue_id, 0, dev->virt_qp_nb))) {
 234                 RTE_LOG(ERR, VHOST_DATA, "(%d) %s: invalid virtqueue idx %d.\n",
 235                         dev->vid, __func__, queue_id);
 236                 return 0;
 237         }
 238
 239         vq = dev->virtqueue[queue_id];
 240         if (unlikely(vq->enabled == 0))
 241                 return 0;
 242
 243         avail_idx = *((volatile uint16_t *)&vq->avail->idx);
 244         start_idx = vq->last_used_idx;
 245         free_entries = avail_idx - start_idx;
 246         count = RTE_MIN(count, free_entries);
 247         count = RTE_MIN(count, (uint32_t)MAX_PKT_BURST);
 248         if (count == 0)
 249                 return 0;
 250
 251         LOG_DEBUG(VHOST_DATA, "(%d) start_idx %d | end_idx %d\n",
 252                 dev->vid, start_idx, start_idx + count);
 253
 254         /* Retrieve all of the desc indexes first to avoid caching issues. */
 255         rte_prefetch0(&vq->avail->ring[start_idx & (vq->size - 1)]);
 256         for (i = 0; i < count; i++) {
 257                 used_idx = (start_idx + i) & (vq->size - 1);
 258                 desc_indexes[i] = vq->avail->ring[used_idx];
 259                 vq->used->ring[used_idx].id = desc_indexes[i];
 260                 vq->used->ring[used_idx].len = pkts[i]->pkt_len +
 261                                                dev->vhost_hlen;
 262                 vhost_log_used_vring(dev, vq,
 263                         offsetof(struct vring_used, ring[used_idx]),
 264                         sizeof(vq->used->ring[used_idx]));
 265         }
 266
 267         rte_prefetch0(&vq->desc[desc_indexes[0]]);
 268         for (i = 0; i < count; i++) {
 269                 uint16_t desc_idx = desc_indexes[i];
 270                 int err;
 271
 272                 err = copy_mbuf_to_desc(dev, vq, pkts[i], desc_idx);
 273                 if (unlikely(err)) {
 274                         used_idx = (start_idx + i) & (vq->size - 1);
 275                         vq->used->ring[used_idx].len = dev->vhost_hlen;
 276                         vhost_log_used_vring(dev, vq,
 277                                 offsetof(struct vring_used, ring[used_idx]),
 278                                 sizeof(vq->used->ring[used_idx]));
 279                 }
 280
 281                 if (i + 1 < count)
 282                         rte_prefetch0(&vq->desc[desc_indexes[i+1]]);
 283         }
 284
 285         rte_smp_wmb();
 286
 287         *(volatile uint16_t *)&vq->used->idx += count;
 288         vq->last_used_idx += count;
 289         vhost_log_used_vring(dev, vq,
 290                 offsetof(struct vring_used, idx),
 291                 sizeof(vq->used->idx));
 292
 293         /* flush used->idx update before we read avail->flags. */
 294         rte_mb();
 295
 296         /* Kick the guest if necessary. */
 297         if (!(vq->avail->flags & VRING_AVAIL_F_NO_INTERRUPT)
 298                         && (vq->callfd >= 0))
 299                 eventfd_write(vq->callfd, (eventfd_t)1);
 300         return count;
 301 }
 302
 303 static inline int
 304 fill_vec_buf(struct vhost_virtqueue *vq, uint32_t avail_idx,
 305              uint32_t *allocated, uint32_t *vec_idx,
 306              struct buf_vector *buf_vec)
 307 {
 308         uint16_t idx = vq->avail->ring[avail_idx & (vq->size - 1)];
 309         uint32_t vec_id = *vec_idx;
 310         uint32_t len    = *allocated;
 311
 312         while (1) {
 313                 if (unlikely(vec_id >= BUF_VECTOR_MAX || idx >= vq->size))
 314                         return -1;
 315
 316                 len += vq->desc[idx].len;
 317                 buf_vec[vec_id].buf_addr = vq->desc[idx].addr;
 318                 buf_vec[vec_id].buf_len  = vq->desc[idx].len;
 319                 buf_vec[vec_id].desc_idx = idx;
 320                 vec_id++;
 321
 322                 if ((vq->desc[idx].flags & VRING_DESC_F_NEXT) == 0)
 323                         break;
 324
 325                 idx = vq->desc[idx].next;
 326         }
 327
 328         *allocated = len;
 329         *vec_idx   = vec_id;
 330
 331         return 0;
 332 }
 333
 334 /*
 335  * Returns -1 on fail, 0 on success
 336  */
 337 static inline int
 338 reserve_avail_buf_mergeable(struct vhost_virtqueue *vq, uint32_t size,
 339                             uint16_t *end, struct buf_vector *buf_vec)
 340 {
 341         uint16_t cur_idx;
 342         uint16_t avail_idx;
 343         uint32_t allocated = 0;
 344         uint32_t vec_idx = 0;
 345         uint16_t tries = 0;
 346
 347         cur_idx  = vq->last_used_idx;
 348
 349         while (1) {
 350                 avail_idx = *((volatile uint16_t *)&vq->avail->idx);
 351                 if (unlikely(cur_idx == avail_idx))
 352                         return -1;
 353
 354                 if (unlikely(fill_vec_buf(vq, cur_idx, &allocated,
 355                                           &vec_idx, buf_vec) < 0))
 356                         return -1;
 357
 358                 cur_idx++;
 359                 tries++;
 360
 361                 if (allocated >= size)
 362                         break;
 363
 364                 /*
 365                  * if we tried all available ring items, and still
 366                  * can't get enough buf, it means something abnormal
 367                  * happened.
 368                  */
 369                 if (unlikely(tries >= vq->size))
 370                         return -1;
 371         }
 372
 373         *end = cur_idx;
 374         return 0;
 375 }
 376
 377 static inline uint32_t __attribute__((always_inline))
 378 copy_mbuf_to_desc_mergeable(struct virtio_net *dev, struct vhost_virtqueue *vq,
 379                             uint16_t end_idx, struct rte_mbuf *m,
 380                             struct buf_vector *buf_vec)
 381 {
 382         struct virtio_net_hdr_mrg_rxbuf virtio_hdr = {{0, 0, 0, 0, 0, 0}, 0};
 383         uint32_t vec_idx = 0;
 384         uint16_t start_idx = vq->last_used_idx;
 385         uint16_t cur_idx = start_idx;
 386         uint64_t desc_addr;
 387         uint32_t mbuf_offset, mbuf_avail;
 388         uint32_t desc_offset, desc_avail;
 389         uint32_t cpy_len;
 390         uint16_t desc_idx, used_idx;
 391
 392         if (unlikely(m == NULL))
 393                 return 0;
 394
 395         LOG_DEBUG(VHOST_DATA, "(%d) current index %d | end index %d\n",
 396                 dev->vid, cur_idx, end_idx);
 397
 398         desc_addr = gpa_to_vva(dev, buf_vec[vec_idx].buf_addr);
 399         if (buf_vec[vec_idx].buf_len < dev->vhost_hlen || !desc_addr)
 400                 return 0;
 401
 402         rte_prefetch0((void *)(uintptr_t)desc_addr);
 403
 404         virtio_hdr.num_buffers = end_idx - start_idx;
 405         LOG_DEBUG(VHOST_DATA, "(%d) RX: num merge buffers %d\n",
 406                 dev->vid, virtio_hdr.num_buffers);
 407
 408         virtio_enqueue_offload(m, &virtio_hdr.hdr);
 409         copy_virtio_net_hdr(dev, desc_addr, virtio_hdr);
 410         vhost_log_write(dev, buf_vec[vec_idx].buf_addr, dev->vhost_hlen);
 411         PRINT_PACKET(dev, (uintptr_t)desc_addr, dev->vhost_hlen, 0);
 412
 413         desc_avail  = buf_vec[vec_idx].buf_len - dev->vhost_hlen;
 414         desc_offset = dev->vhost_hlen;
 415
 416         mbuf_avail  = rte_pktmbuf_data_len(m);
 417         mbuf_offset = 0;
 418         while (mbuf_avail != 0 || m->next != NULL) {
 419                 /* done with current desc buf, get the next one */
 420                 if (desc_avail == 0) {
 421                         desc_idx = buf_vec[vec_idx].desc_idx;
 422
 423                         if (!(vq->desc[desc_idx].flags & VRING_DESC_F_NEXT)) {
 424                                 /* Update used ring with desc information */
 425                                 used_idx = cur_idx++ & (vq->size - 1);
 426                                 vq->used->ring[used_idx].id  = desc_idx;
 427                                 vq->used->ring[used_idx].len = desc_offset;
 428                                 vhost_log_used_vring(dev, vq,
 429                                         offsetof(struct vring_used,
 430                                                  ring[used_idx]),
 431                                         sizeof(vq->used->ring[used_idx]));
 432                         }
 433
 434                         vec_idx++;
 435                         desc_addr = gpa_to_vva(dev, buf_vec[vec_idx].buf_addr);
 436                         if (unlikely(!desc_addr))
 437                                 return 0;
 438
 439                         /* Prefetch buffer address. */
 440                         rte_prefetch0((void *)(uintptr_t)desc_addr);
 441                         desc_offset = 0;
 442                         desc_avail  = buf_vec[vec_idx].buf_len;
 443                 }
 444
 445                 /* done with current mbuf, get the next one */
 446                 if (mbuf_avail == 0) {
 447                         m = m->next;
 448
 449                         mbuf_offset = 0;
 450                         mbuf_avail  = rte_pktmbuf_data_len(m);
 451                 }
 452
 453                 cpy_len = RTE_MIN(desc_avail, mbuf_avail);
 454                 rte_memcpy((void *)((uintptr_t)(desc_addr + desc_offset)),
 455                         rte_pktmbuf_mtod_offset(m, void *, mbuf_offset),
 456                         cpy_len);
 457                 vhost_log_write(dev, buf_vec[vec_idx].buf_addr + desc_offset,
 458                         cpy_len);
 459                 PRINT_PACKET(dev, (uintptr_t)(desc_addr + desc_offset),
 460                         cpy_len, 0);
 461
 462                 mbuf_avail  -= cpy_len;
 463                 mbuf_offset += cpy_len;
 464                 desc_avail  -= cpy_len;
 465                 desc_offset += cpy_len;
 466         }
 467
 468         used_idx = cur_idx & (vq->size - 1);
 469         vq->used->ring[used_idx].id = buf_vec[vec_idx].desc_idx;
 470         vq->used->ring[used_idx].len = desc_offset;
 471         vhost_log_used_vring(dev, vq,
 472                 offsetof(struct vring_used, ring[used_idx]),
 473                 sizeof(vq->used->ring[used_idx]));
 474
 475         return end_idx - start_idx;
 476 }
 477
 478 static inline uint32_t __attribute__((always_inline))
 479 virtio_dev_merge_rx(struct virtio_net *dev, uint16_t queue_id,
 480         struct rte_mbuf **pkts, uint32_t count)
 481 {
 482         struct vhost_virtqueue *vq;
 483         uint32_t pkt_idx = 0, nr_used = 0;
 484         uint16_t end;
 485         struct buf_vector buf_vec[BUF_VECTOR_MAX];
 486
 487         LOG_DEBUG(VHOST_DATA, "(%d) %s\n", dev->vid, __func__);
 488         if (unlikely(!is_valid_virt_queue_idx(queue_id, 0, dev->virt_qp_nb))) {
 489                 RTE_LOG(ERR, VHOST_DATA, "(%d) %s: invalid virtqueue idx %d.\n",
 490                         dev->vid, __func__, queue_id);
 491                 return 0;
 492         }
 493
 494         vq = dev->virtqueue[queue_id];
 495         if (unlikely(vq->enabled == 0))
 496                 return 0;
 497
 498         count = RTE_MIN((uint32_t)MAX_PKT_BURST, count);
 499         if (count == 0)
 500                 return 0;
 501
 502         for (pkt_idx = 0; pkt_idx < count; pkt_idx++) {
 503                 uint32_t pkt_len = pkts[pkt_idx]->pkt_len + dev->vhost_hlen;
 504
 505                 if (unlikely(reserve_avail_buf_mergeable(vq, pkt_len,
 506                                                          &end, buf_vec) < 0)) {
 507                         LOG_DEBUG(VHOST_DATA,
 508                                 "(%d) failed to get enough desc from vring\n",
 509                                 dev->vid);
 510                         break;
 511                 }
 512
 513                 nr_used = copy_mbuf_to_desc_mergeable(dev, vq, end,
 514                                                       pkts[pkt_idx], buf_vec);
 515                 rte_smp_wmb();
 516
 517                 *(volatile uint16_t *)&vq->used->idx += nr_used;
 518                 vhost_log_used_vring(dev, vq, offsetof(struct vring_used, idx),
 519                         sizeof(vq->used->idx));
 520                 vq->last_used_idx += nr_used;
 521         }
 522
 523         if (likely(pkt_idx)) {
 524                 /* flush used->idx update before we read avail->flags. */
 525                 rte_mb();
 526
 527                 /* Kick the guest if necessary. */
 528                 if (!(vq->avail->flags & VRING_AVAIL_F_NO_INTERRUPT)
 529                                 && (vq->callfd >= 0))
 530                         eventfd_write(vq->callfd, (eventfd_t)1);
 531         }
 532
 533         return pkt_idx;
 534 }
 535
 536 uint16_t
 537 rte_vhost_enqueue_burst(int vid, uint16_t queue_id,
 538         struct rte_mbuf **pkts, uint16_t count)
 539 {
 540         struct virtio_net *dev = get_device(vid);
 541
 542         if (!dev)
 543                 return 0;
 544
 545         if (dev->features & (1 << VIRTIO_NET_F_MRG_RXBUF))
 546                 return virtio_dev_merge_rx(dev, queue_id, pkts, count);
 547         else
 548                 return virtio_dev_rx(dev, queue_id, pkts, count);
 549 }
 550
 551 static void
 552 parse_ethernet(struct rte_mbuf *m, uint16_t *l4_proto, void **l4_hdr)
 553 {
 554         struct ipv4_hdr *ipv4_hdr;
 555         struct ipv6_hdr *ipv6_hdr;
 556         void *l3_hdr = NULL;
 557         struct ether_hdr *eth_hdr;
 558         uint16_t ethertype;
 559
 560         eth_hdr = rte_pktmbuf_mtod(m, struct ether_hdr *);
 561
 562         m->l2_len = sizeof(struct ether_hdr);
 563         ethertype = rte_be_to_cpu_16(eth_hdr->ether_type);
 564
 565         if (ethertype == ETHER_TYPE_VLAN) {
 566                 struct vlan_hdr *vlan_hdr = (struct vlan_hdr *)(eth_hdr + 1);
 567
 568                 m->l2_len += sizeof(struct vlan_hdr);
 569                 ethertype = rte_be_to_cpu_16(vlan_hdr->eth_proto);
 570         }
 571
 572         l3_hdr = (char *)eth_hdr + m->l2_len;
 573
 574         switch (ethertype) {
 575         case ETHER_TYPE_IPv4:
 576                 ipv4_hdr = (struct ipv4_hdr *)l3_hdr;
 577                 *l4_proto = ipv4_hdr->next_proto_id;
 578                 m->l3_len = (ipv4_hdr->version_ihl & 0x0f) * 4;
 579                 *l4_hdr = (char *)l3_hdr + m->l3_len;
 580                 m->ol_flags |= PKT_TX_IPV4;
 581                 break;
 582         case ETHER_TYPE_IPv6:
 583                 ipv6_hdr = (struct ipv6_hdr *)l3_hdr;
 584                 *l4_proto = ipv6_hdr->proto;
 585                 m->l3_len = sizeof(struct ipv6_hdr);
 586                 *l4_hdr = (char *)l3_hdr + m->l3_len;
 587                 m->ol_flags |= PKT_TX_IPV6;
 588                 break;
 589         default:
 590                 m->l3_len = 0;
 591                 *l4_proto = 0;
 592                 break;
 593         }
 594 }
 595
 596 static inline void __attribute__((always_inline))
 597 vhost_dequeue_offload(struct virtio_net_hdr *hdr, struct rte_mbuf *m)
 598 {
 599         uint16_t l4_proto = 0;
 600         void *l4_hdr = NULL;
 601         struct tcp_hdr *tcp_hdr = NULL;
 602
 603         parse_ethernet(m, &l4_proto, &l4_hdr);
 604         if (hdr->flags == VIRTIO_NET_HDR_F_NEEDS_CSUM) {
 605                 if (hdr->csum_start == (m->l2_len + m->l3_len)) {
 606                         switch (hdr->csum_offset) {
 607                         case (offsetof(struct tcp_hdr, cksum)):
 608                                 if (l4_proto == IPPROTO_TCP)
 609                                         m->ol_flags |= PKT_TX_TCP_CKSUM;
 610                                 break;
 611                         case (offsetof(struct udp_hdr, dgram_cksum)):
 612                                 if (l4_proto == IPPROTO_UDP)
 613                                         m->ol_flags |= PKT_TX_UDP_CKSUM;
 614                                 break;
 615                         case (offsetof(struct sctp_hdr, cksum)):
 616                                 if (l4_proto == IPPROTO_SCTP)
 617                                         m->ol_flags |= PKT_TX_SCTP_CKSUM;
 618                                 break;
 619                         default:
 620                                 break;
 621                         }
 622                 }
 623         }
 624
 625         if (hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) {
 626                 switch (hdr->gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
 627                 case VIRTIO_NET_HDR_GSO_TCPV4:
 628                 case VIRTIO_NET_HDR_GSO_TCPV6:
 629                         tcp_hdr = (struct tcp_hdr *)l4_hdr;
 630                         m->ol_flags |= PKT_TX_TCP_SEG;
 631                         m->tso_segsz = hdr->gso_size;
 632                         m->l4_len = (tcp_hdr->data_off & 0xf0) >> 2;
 633                         break;
 634                 default:
 635                         RTE_LOG(WARNING, VHOST_DATA,
 636                                 "unsupported gso type %u.\n", hdr->gso_type);
 637                         break;
 638                 }
 639         }
 640 }
 641
 642 #define RARP_PKT_SIZE   64
 643
 644 static int
 645 make_rarp_packet(struct rte_mbuf *rarp_mbuf, const struct ether_addr *mac)
 646 {
 647         struct ether_hdr *eth_hdr;
 648         struct arp_hdr  *rarp;
 649
 650         if (rarp_mbuf->buf_len < 64) {
 651                 RTE_LOG(WARNING, VHOST_DATA,
 652                         "failed to make RARP; mbuf size too small %u (< %d)\n",
 653                         rarp_mbuf->buf_len, RARP_PKT_SIZE);
 654                 return -1;
 655         }
 656
 657         /* Ethernet header. */
 658         eth_hdr = rte_pktmbuf_mtod_offset(rarp_mbuf, struct ether_hdr *, 0);
 659         memset(eth_hdr->d_addr.addr_bytes, 0xff, ETHER_ADDR_LEN);
 660         ether_addr_copy(mac, &eth_hdr->s_addr);
 661         eth_hdr->ether_type = htons(ETHER_TYPE_RARP);
 662
 663         /* RARP header. */
 664         rarp = (struct arp_hdr *)(eth_hdr + 1);
 665         rarp->arp_hrd = htons(ARP_HRD_ETHER);
 666         rarp->arp_pro = htons(ETHER_TYPE_IPv4);
 667         rarp->arp_hln = ETHER_ADDR_LEN;
 668         rarp->arp_pln = 4;
 669         rarp->arp_op  = htons(ARP_OP_REVREQUEST);
 670
 671         ether_addr_copy(mac, &rarp->arp_data.arp_sha);
 672         ether_addr_copy(mac, &rarp->arp_data.arp_tha);
 673         memset(&rarp->arp_data.arp_sip, 0x00, 4);
 674         memset(&rarp->arp_data.arp_tip, 0x00, 4);
 675
 676         rarp_mbuf->pkt_len  = rarp_mbuf->data_len = RARP_PKT_SIZE;
 677
 678         return 0;
 679 }
 680
 681 static inline int __attribute__((always_inline))
 682 copy_desc_to_mbuf(struct virtio_net *dev, struct vhost_virtqueue *vq,
 683                   struct rte_mbuf *m, uint16_t desc_idx,
 684                   struct rte_mempool *mbuf_pool)
 685 {
 686         struct vring_desc *desc;
 687         uint64_t desc_addr;
 688         uint32_t desc_avail, desc_offset;
 689         uint32_t mbuf_avail, mbuf_offset;
 690         uint32_t cpy_len;
 691         struct rte_mbuf *cur = m, *prev = m;
 692         struct virtio_net_hdr *hdr;
 693         /* A counter to avoid desc dead loop chain */
 694         uint32_t nr_desc = 1;
 695
 696         desc = &vq->desc[desc_idx];
 697         if (unlikely(desc->len < dev->vhost_hlen))
 698                 return -1;
 699
 700         desc_addr = gpa_to_vva(dev, desc->addr);
 701         if (unlikely(!desc_addr))
 702                 return -1;
 703
 704         hdr = (struct virtio_net_hdr *)((uintptr_t)desc_addr);
 705         rte_prefetch0(hdr);
 706
 707         /*
 708          * A virtio driver normally uses at least 2 desc buffers
 709          * for Tx: the first for storing the header, and others
 710          * for storing the data.
 711          */
 712         if (likely((desc->len == dev->vhost_hlen) &&
 713                    (desc->flags & VRING_DESC_F_NEXT) != 0)) {
 714                 desc = &vq->desc[desc->next];
 715
 716                 desc_addr = gpa_to_vva(dev, desc->addr);
 717                 if (unlikely(!desc_addr))
 718                         return -1;
 719
 720                 rte_prefetch0((void *)(uintptr_t)desc_addr);
 721
 722                 desc_offset = 0;
 723                 desc_avail  = desc->len;
 724                 nr_desc    += 1;
 725
 726                 PRINT_PACKET(dev, (uintptr_t)desc_addr, desc->len, 0);
 727         } else {
 728                 desc_avail  = desc->len - dev->vhost_hlen;
 729                 desc_offset = dev->vhost_hlen;
 730         }
 731
 732         mbuf_offset = 0;
 733         mbuf_avail  = m->buf_len - RTE_PKTMBUF_HEADROOM;
 734         while (1) {
 735                 cpy_len = RTE_MIN(desc_avail, mbuf_avail);
 736                 rte_memcpy(rte_pktmbuf_mtod_offset(cur, void *, mbuf_offset),
 737                         (void *)((uintptr_t)(desc_addr + desc_offset)),
 738                         cpy_len);
 739
 740                 mbuf_avail  -= cpy_len;
 741                 mbuf_offset += cpy_len;
 742                 desc_avail  -= cpy_len;
 743                 desc_offset += cpy_len;
 744
 745                 /* This desc reaches to its end, get the next one */
 746                 if (desc_avail == 0) {
 747                         if ((desc->flags & VRING_DESC_F_NEXT) == 0)
 748                                 break;
 749
 750                         if (unlikely(desc->next >= vq->size ||
 751                                      ++nr_desc > vq->size))
 752                                 return -1;
 753                         desc = &vq->desc[desc->next];
 754
 755                         desc_addr = gpa_to_vva(dev, desc->addr);
 756                         if (unlikely(!desc_addr))
 757                                 return -1;
 758
 759                         rte_prefetch0((void *)(uintptr_t)desc_addr);
 760
 761                         desc_offset = 0;
 762                         desc_avail  = desc->len;
 763
 764                         PRINT_PACKET(dev, (uintptr_t)desc_addr, desc->len, 0);
 765                 }
 766
 767                 /*
 768                  * This mbuf reaches to its end, get a new one
 769                  * to hold more data.
 770                  */
 771                 if (mbuf_avail == 0) {
 772                         cur = rte_pktmbuf_alloc(mbuf_pool);
 773                         if (unlikely(cur == NULL)) {
 774                                 RTE_LOG(ERR, VHOST_DATA, "Failed to "
 775                                         "allocate memory for mbuf.\n");
 776                                 return -1;
 777                         }
 778
 779                         prev->next = cur;
 780                         prev->data_len = mbuf_offset;
 781                         m->nb_segs += 1;
 782                         m->pkt_len += mbuf_offset;
 783                         prev = cur;
 784
 785                         mbuf_offset = 0;
 786                         mbuf_avail  = cur->buf_len - RTE_PKTMBUF_HEADROOM;
 787                 }
 788         }
 789
 790         prev->data_len = mbuf_offset;
 791         m->pkt_len    += mbuf_offset;
 792
 793         if (hdr->flags != 0 || hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE)
 794                 vhost_dequeue_offload(hdr, m);
 795
 796         return 0;
 797 }
 798
 799 uint16_t
 800 rte_vhost_dequeue_burst(int vid, uint16_t queue_id,
 801         struct rte_mempool *mbuf_pool, struct rte_mbuf **pkts, uint16_t count)
 802 {
 803         struct virtio_net *dev;
 804         struct rte_mbuf *rarp_mbuf = NULL;
 805         struct vhost_virtqueue *vq;
 806         uint32_t desc_indexes[MAX_PKT_BURST];
 807         uint32_t used_idx;
 808         uint32_t i = 0;
 809         uint16_t free_entries;
 810         uint16_t avail_idx;
 811
 812         dev = get_device(vid);
 813         if (!dev)
 814                 return 0;
 815
 816         if (unlikely(!is_valid_virt_queue_idx(queue_id, 1, dev->virt_qp_nb))) {
 817                 RTE_LOG(ERR, VHOST_DATA, "(%d) %s: invalid virtqueue idx %d.\n",
 818                         dev->vid, __func__, queue_id);
 819                 return 0;
 820         }
 821
 822         vq = dev->virtqueue[queue_id];
 823         if (unlikely(vq->enabled == 0))
 824                 return 0;
 825
 826         /*
 827          * Construct a RARP broadcast packet, and inject it to the "pkts"
 828          * array, to looks like that guest actually send such packet.
 829          *
 830          * Check user_send_rarp() for more information.
 831          */
 832         if (unlikely(rte_atomic16_cmpset((volatile uint16_t *)
 833                                          &dev->broadcast_rarp.cnt, 1, 0))) {
 834                 rarp_mbuf = rte_pktmbuf_alloc(mbuf_pool);
 835                 if (rarp_mbuf == NULL) {
 836                         RTE_LOG(ERR, VHOST_DATA,
 837                                 "Failed to allocate memory for mbuf.\n");
 838                         return 0;
 839                 }
 840
 841                 if (make_rarp_packet(rarp_mbuf, &dev->mac)) {
 842                         rte_pktmbuf_free(rarp_mbuf);
 843                         rarp_mbuf = NULL;
 844                 } else {
 845                         count -= 1;
 846                 }
 847         }
 848
 849         avail_idx =  *((volatile uint16_t *)&vq->avail->idx);
 850         free_entries = avail_idx - vq->last_used_idx;
 851         if (free_entries == 0)
 852                 goto out;
 853
 854         LOG_DEBUG(VHOST_DATA, "(%d) %s\n", dev->vid, __func__);
 855
 856         /* Prefetch available ring to retrieve head indexes. */
 857         used_idx = vq->last_used_idx & (vq->size - 1);
 858         rte_prefetch0(&vq->avail->ring[used_idx]);
 859         rte_prefetch0(&vq->used->ring[used_idx]);
 860
 861         count = RTE_MIN(count, MAX_PKT_BURST);
 862         count = RTE_MIN(count, free_entries);
 863         LOG_DEBUG(VHOST_DATA, "(%d) about to dequeue %u buffers\n",
 864                         dev->vid, count);
 865
 866         /* Retrieve all of the head indexes first to avoid caching issues. */
 867         for (i = 0; i < count; i++) {
 868                 used_idx = (vq->last_used_idx + i) & (vq->size - 1);
 869                 desc_indexes[i] = vq->avail->ring[used_idx];
 870
 871                 vq->used->ring[used_idx].id  = desc_indexes[i];
 872                 vq->used->ring[used_idx].len = 0;
 873                 vhost_log_used_vring(dev, vq,
 874                                 offsetof(struct vring_used, ring[used_idx]),
 875                                 sizeof(vq->used->ring[used_idx]));
 876         }
 877
 878         /* Prefetch descriptor index. */
 879         rte_prefetch0(&vq->desc[desc_indexes[0]]);
 880         for (i = 0; i < count; i++) {
 881                 int err;
 882
 883                 if (likely(i + 1 < count))
 884                         rte_prefetch0(&vq->desc[desc_indexes[i + 1]]);
 885
 886                 pkts[i] = rte_pktmbuf_alloc(mbuf_pool);
 887                 if (unlikely(pkts[i] == NULL)) {
 888                         RTE_LOG(ERR, VHOST_DATA,
 889                                 "Failed to allocate memory for mbuf.\n");
 890                         break;
 891                 }
 892                 err = copy_desc_to_mbuf(dev, vq, pkts[i], desc_indexes[i],
 893                                         mbuf_pool);
 894                 if (unlikely(err)) {
 895                         rte_pktmbuf_free(pkts[i]);
 896                         break;
 897                 }
 898         }
 899
 900         rte_smp_wmb();
 901         rte_smp_rmb();
 902         vq->used->idx += i;
 903         vq->last_used_idx += i;
 904         vhost_log_used_vring(dev, vq, offsetof(struct vring_used, idx),
 905                         sizeof(vq->used->idx));
 906
 907         /* Kick guest if required. */
 908         if (!(vq->avail->flags & VRING_AVAIL_F_NO_INTERRUPT)
 909                         && (vq->callfd >= 0))
 910                 eventfd_write(vq->callfd, (eventfd_t)1);
 911
 912 out:
 913         if (unlikely(rarp_mbuf != NULL)) {
 914                 /*
 915                  * Inject it to the head of "pkts" array, so that switch's mac
 916                  * learning table will get updated first.
 917                  */
 918                 memmove(&pkts[1], pkts, i * sizeof(struct rte_mbuf *));
 919                 pkts[0] = rarp_mbuf;
 920                 i += 1;
 921         }
 922
 923         return i;
 924 }