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 vhost_virtqueue *vq, uint64_t desc_addr,
 130                     struct virtio_net_hdr_mrg_rxbuf hdr)
 131 {
 132         if (vq->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, uint32_t *copied)
 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 < vq->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(vq, desc_addr, virtio_hdr);
 158         vhost_log_write(dev, desc->addr, vq->vhost_hlen);
 159         PRINT_PACKET(dev, (uintptr_t)desc_addr, vq->vhost_hlen, 0);
 160
 161         desc_offset = vq->vhost_hlen;
 162         desc_avail  = desc->len - vq->vhost_hlen;
 163
 164         *copied = rte_pktmbuf_pkt_len(m);
 165         mbuf_avail  = rte_pktmbuf_data_len(m);
 166         mbuf_offset = 0;
 167         while (mbuf_avail != 0 || m->next != NULL) {
 168                 /* done with current mbuf, fetch next */
 169                 if (mbuf_avail == 0) {
 170                         m = m->next;
 171
 172                         mbuf_offset = 0;
 173                         mbuf_avail  = rte_pktmbuf_data_len(m);
 174                 }
 175
 176                 /* done with current desc buf, fetch next */
 177                 if (desc_avail == 0) {
 178                         if ((desc->flags & VRING_DESC_F_NEXT) == 0) {
 179                                 /* Room in vring buffer is not enough */
 180                                 return -1;
 181                         }
 182                         if (unlikely(desc->next >= vq->size))
 183                                 return -1;
 184
 185                         desc = &vq->desc[desc->next];
 186                         desc_addr   = gpa_to_vva(dev, desc->addr);
 187                         desc_offset = 0;
 188                         desc_avail  = desc->len;
 189                 }
 190
 191                 cpy_len = RTE_MIN(desc_avail, mbuf_avail);
 192                 rte_memcpy((void *)((uintptr_t)(desc_addr + desc_offset)),
 193                         rte_pktmbuf_mtod_offset(m, void *, mbuf_offset),
 194                         cpy_len);
 195                 vhost_log_write(dev, desc->addr + desc_offset, cpy_len);
 196                 PRINT_PACKET(dev, (uintptr_t)(desc_addr + desc_offset),
 197                              cpy_len, 0);
 198
 199                 mbuf_avail  -= cpy_len;
 200                 mbuf_offset += cpy_len;
 201                 desc_avail  -= cpy_len;
 202                 desc_offset += cpy_len;
 203         }
 204
 205         return 0;
 206 }
 207
 208 /*
 209  * As many data cores may want to access available buffers
 210  * they need to be reserved.
 211  */
 212 static inline uint32_t
 213 reserve_avail_buf(struct vhost_virtqueue *vq, uint32_t count,
 214                   uint16_t *start, uint16_t *end)
 215 {
 216         uint16_t res_start_idx;
 217         uint16_t res_end_idx;
 218         uint16_t avail_idx;
 219         uint16_t free_entries;
 220         int success;
 221
 222         count = RTE_MIN(count, (uint32_t)MAX_PKT_BURST);
 223
 224 again:
 225         res_start_idx = vq->last_used_idx_res;
 226         avail_idx = *((volatile uint16_t *)&vq->avail->idx);
 227
 228         free_entries = avail_idx - res_start_idx;
 229         count = RTE_MIN(count, free_entries);
 230         if (count == 0)
 231                 return 0;
 232
 233         res_end_idx = res_start_idx + count;
 234
 235         /*
 236          * update vq->last_used_idx_res atomically; try again if failed.
 237          *
 238          * TODO: Allow to disable cmpset if no concurrency in application.
 239          */
 240         success = rte_atomic16_cmpset(&vq->last_used_idx_res,
 241                                       res_start_idx, res_end_idx);
 242         if (unlikely(!success))
 243                 goto again;
 244
 245         *start = res_start_idx;
 246         *end   = res_end_idx;
 247
 248         return count;
 249 }
 250
 251 /**
 252  * This function adds buffers to the virtio devices RX virtqueue. Buffers can
 253  * be received from the physical port or from another virtio device. A packet
 254  * count is returned to indicate the number of packets that are succesfully
 255  * added to the RX queue. This function works when the mbuf is scattered, but
 256  * it doesn't support the mergeable feature.
 257  */
 258 static inline uint32_t __attribute__((always_inline))
 259 virtio_dev_rx(struct virtio_net *dev, uint16_t queue_id,
 260               struct rte_mbuf **pkts, uint32_t count)
 261 {
 262         struct vhost_virtqueue *vq;
 263         uint16_t res_start_idx, res_end_idx;
 264         uint16_t desc_indexes[MAX_PKT_BURST];
 265         uint32_t i;
 266
 267         LOG_DEBUG(VHOST_DATA, "(%"PRIu64") virtio_dev_rx()\n", dev->device_fh);
 268         if (unlikely(!is_valid_virt_queue_idx(queue_id, 0, dev->virt_qp_nb))) {
 269                 RTE_LOG(ERR, VHOST_DATA,
 270                         "%s (%"PRIu64"): virtqueue idx:%d invalid.\n",
 271                         __func__, dev->device_fh, queue_id);
 272                 return 0;
 273         }
 274
 275         vq = dev->virtqueue[queue_id];
 276         if (unlikely(vq->enabled == 0))
 277                 return 0;
 278
 279         count = reserve_avail_buf(vq, count, &res_start_idx, &res_end_idx);
 280         if (count == 0)
 281                 return 0;
 282
 283         LOG_DEBUG(VHOST_DATA,
 284                 "(%"PRIu64") res_start_idx %d| res_end_idx Index %d\n",
 285                 dev->device_fh, res_start_idx, res_end_idx);
 286
 287         /* Retrieve all of the desc indexes first to avoid caching issues. */
 288         rte_prefetch0(&vq->avail->ring[res_start_idx & (vq->size - 1)]);
 289         for (i = 0; i < count; i++) {
 290                 desc_indexes[i] = vq->avail->ring[(res_start_idx + i) &
 291                                                   (vq->size - 1)];
 292         }
 293
 294         rte_prefetch0(&vq->desc[desc_indexes[0]]);
 295         for (i = 0; i < count; i++) {
 296                 uint16_t desc_idx = desc_indexes[i];
 297                 uint16_t used_idx = (res_start_idx + i) & (vq->size - 1);
 298                 uint32_t copied;
 299                 int err;
 300
 301                 err = copy_mbuf_to_desc(dev, vq, pkts[i], desc_idx, &copied);
 302
 303                 vq->used->ring[used_idx].id = desc_idx;
 304                 if (unlikely(err))
 305                         vq->used->ring[used_idx].len = vq->vhost_hlen;
 306                 else
 307                         vq->used->ring[used_idx].len = copied + vq->vhost_hlen;
 308                 vhost_log_used_vring(dev, vq,
 309                         offsetof(struct vring_used, ring[used_idx]),
 310                         sizeof(vq->used->ring[used_idx]));
 311
 312                 if (i + 1 < count)
 313                         rte_prefetch0(&vq->desc[desc_indexes[i+1]]);
 314         }
 315
 316         rte_smp_wmb();
 317
 318         /* Wait until it's our turn to add our buffer to the used ring. */
 319         while (unlikely(vq->last_used_idx != res_start_idx))
 320                 rte_pause();
 321
 322         *(volatile uint16_t *)&vq->used->idx += count;
 323         vq->last_used_idx = res_end_idx;
 324         vhost_log_used_vring(dev, vq,
 325                 offsetof(struct vring_used, idx),
 326                 sizeof(vq->used->idx));
 327
 328         /* flush used->idx update before we read avail->flags. */
 329         rte_mb();
 330
 331         /* Kick the guest if necessary. */
 332         if (!(vq->avail->flags & VRING_AVAIL_F_NO_INTERRUPT)
 333                         && (vq->callfd >= 0))
 334                 eventfd_write(vq->callfd, (eventfd_t)1);
 335         return count;
 336 }
 337
 338 static inline int
 339 fill_vec_buf(struct vhost_virtqueue *vq, uint32_t avail_idx,
 340              uint32_t *allocated, uint32_t *vec_idx)
 341 {
 342         uint16_t idx = vq->avail->ring[avail_idx & (vq->size - 1)];
 343         uint32_t vec_id = *vec_idx;
 344         uint32_t len    = *allocated;
 345
 346         while (1) {
 347                 if (unlikely(vec_id >= BUF_VECTOR_MAX || idx >= vq->size))
 348                         return -1;
 349
 350                 len += vq->desc[idx].len;
 351                 vq->buf_vec[vec_id].buf_addr = vq->desc[idx].addr;
 352                 vq->buf_vec[vec_id].buf_len  = vq->desc[idx].len;
 353                 vq->buf_vec[vec_id].desc_idx = idx;
 354                 vec_id++;
 355
 356                 if ((vq->desc[idx].flags & VRING_DESC_F_NEXT) == 0)
 357                         break;
 358
 359                 idx = vq->desc[idx].next;
 360         }
 361
 362         *allocated = len;
 363         *vec_idx   = vec_id;
 364
 365         return 0;
 366 }
 367
 368 /*
 369  * As many data cores may want to access available buffers concurrently,
 370  * they need to be reserved.
 371  *
 372  * Returns -1 on fail, 0 on success
 373  */
 374 static inline int
 375 reserve_avail_buf_mergeable(struct vhost_virtqueue *vq, uint32_t size,
 376                             uint16_t *start, uint16_t *end)
 377 {
 378         uint16_t res_start_idx;
 379         uint16_t res_cur_idx;
 380         uint16_t avail_idx;
 381         uint32_t allocated;
 382         uint32_t vec_idx;
 383         uint16_t tries;
 384
 385 again:
 386         res_start_idx = vq->last_used_idx_res;
 387         res_cur_idx  = res_start_idx;
 388
 389         allocated = 0;
 390         vec_idx   = 0;
 391         tries     = 0;
 392         while (1) {
 393                 avail_idx = *((volatile uint16_t *)&vq->avail->idx);
 394                 if (unlikely(res_cur_idx == avail_idx))
 395                         return -1;
 396
 397                 if (unlikely(fill_vec_buf(vq, res_cur_idx, &allocated,
 398                                           &vec_idx) < 0))
 399                         return -1;
 400
 401                 res_cur_idx++;
 402                 tries++;
 403
 404                 if (allocated >= size)
 405                         break;
 406
 407                 /*
 408                  * if we tried all available ring items, and still
 409                  * can't get enough buf, it means something abnormal
 410                  * happened.
 411                  */
 412                 if (unlikely(tries >= vq->size))
 413                         return -1;
 414         }
 415
 416         /*
 417          * update vq->last_used_idx_res atomically.
 418          * retry again if failed.
 419          */
 420         if (rte_atomic16_cmpset(&vq->last_used_idx_res,
 421                                 res_start_idx, res_cur_idx) == 0)
 422                 goto again;
 423
 424         *start = res_start_idx;
 425         *end   = res_cur_idx;
 426         return 0;
 427 }
 428
 429 static inline uint32_t __attribute__((always_inline))
 430 copy_mbuf_to_desc_mergeable(struct virtio_net *dev, struct vhost_virtqueue *vq,
 431                             uint16_t res_start_idx, uint16_t res_end_idx,
 432                             struct rte_mbuf *m)
 433 {
 434         struct virtio_net_hdr_mrg_rxbuf virtio_hdr = {{0, 0, 0, 0, 0, 0}, 0};
 435         uint32_t vec_idx = 0;
 436         uint16_t cur_idx = res_start_idx;
 437         uint64_t desc_addr;
 438         uint32_t mbuf_offset, mbuf_avail;
 439         uint32_t desc_offset, desc_avail;
 440         uint32_t cpy_len;
 441         uint16_t desc_idx, used_idx;
 442
 443         if (unlikely(m == NULL))
 444                 return 0;
 445
 446         LOG_DEBUG(VHOST_DATA,
 447                 "(%"PRIu64") Current Index %d| End Index %d\n",
 448                 dev->device_fh, cur_idx, res_end_idx);
 449
 450         if (vq->buf_vec[vec_idx].buf_len < vq->vhost_hlen)
 451                 return -1;
 452
 453         desc_addr = gpa_to_vva(dev, vq->buf_vec[vec_idx].buf_addr);
 454         rte_prefetch0((void *)(uintptr_t)desc_addr);
 455
 456         virtio_hdr.num_buffers = res_end_idx - res_start_idx;
 457         LOG_DEBUG(VHOST_DATA, "(%"PRIu64") RX: Num merge buffers %d\n",
 458                 dev->device_fh, virtio_hdr.num_buffers);
 459
 460         virtio_enqueue_offload(m, &virtio_hdr.hdr);
 461         copy_virtio_net_hdr(vq, desc_addr, virtio_hdr);
 462         vhost_log_write(dev, vq->buf_vec[vec_idx].buf_addr, vq->vhost_hlen);
 463         PRINT_PACKET(dev, (uintptr_t)desc_addr, vq->vhost_hlen, 0);
 464
 465         desc_avail  = vq->buf_vec[vec_idx].buf_len - vq->vhost_hlen;
 466         desc_offset = vq->vhost_hlen;
 467
 468         mbuf_avail  = rte_pktmbuf_data_len(m);
 469         mbuf_offset = 0;
 470         while (mbuf_avail != 0 || m->next != NULL) {
 471                 /* done with current desc buf, get the next one */
 472                 if (desc_avail == 0) {
 473                         desc_idx = vq->buf_vec[vec_idx].desc_idx;
 474
 475                         if (!(vq->desc[desc_idx].flags & VRING_DESC_F_NEXT)) {
 476                                 /* Update used ring with desc information */
 477                                 used_idx = cur_idx++ & (vq->size - 1);
 478                                 vq->used->ring[used_idx].id  = desc_idx;
 479                                 vq->used->ring[used_idx].len = desc_offset;
 480                                 vhost_log_used_vring(dev, vq,
 481                                         offsetof(struct vring_used,
 482                                                  ring[used_idx]),
 483                                         sizeof(vq->used->ring[used_idx]));
 484                         }
 485
 486                         vec_idx++;
 487                         desc_addr = gpa_to_vva(dev, vq->buf_vec[vec_idx].buf_addr);
 488
 489                         /* Prefetch buffer address. */
 490                         rte_prefetch0((void *)(uintptr_t)desc_addr);
 491                         desc_offset = 0;
 492                         desc_avail  = vq->buf_vec[vec_idx].buf_len;
 493                 }
 494
 495                 /* done with current mbuf, get the next one */
 496                 if (mbuf_avail == 0) {
 497                         m = m->next;
 498
 499                         mbuf_offset = 0;
 500                         mbuf_avail  = rte_pktmbuf_data_len(m);
 501                 }
 502
 503                 cpy_len = RTE_MIN(desc_avail, mbuf_avail);
 504                 rte_memcpy((void *)((uintptr_t)(desc_addr + desc_offset)),
 505                         rte_pktmbuf_mtod_offset(m, void *, mbuf_offset),
 506                         cpy_len);
 507                 vhost_log_write(dev, vq->buf_vec[vec_idx].buf_addr + desc_offset,
 508                         cpy_len);
 509                 PRINT_PACKET(dev, (uintptr_t)(desc_addr + desc_offset),
 510                         cpy_len, 0);
 511
 512                 mbuf_avail  -= cpy_len;
 513                 mbuf_offset += cpy_len;
 514                 desc_avail  -= cpy_len;
 515                 desc_offset += cpy_len;
 516         }
 517
 518         used_idx = cur_idx & (vq->size - 1);
 519         vq->used->ring[used_idx].id = vq->buf_vec[vec_idx].desc_idx;
 520         vq->used->ring[used_idx].len = desc_offset;
 521         vhost_log_used_vring(dev, vq,
 522                 offsetof(struct vring_used, ring[used_idx]),
 523                 sizeof(vq->used->ring[used_idx]));
 524
 525         return res_end_idx - res_start_idx;
 526 }
 527
 528 static inline uint32_t __attribute__((always_inline))
 529 virtio_dev_merge_rx(struct virtio_net *dev, uint16_t queue_id,
 530         struct rte_mbuf **pkts, uint32_t count)
 531 {
 532         struct vhost_virtqueue *vq;
 533         uint32_t pkt_idx = 0, nr_used = 0;
 534         uint16_t start, end;
 535
 536         LOG_DEBUG(VHOST_DATA, "(%"PRIu64") virtio_dev_merge_rx()\n",
 537                 dev->device_fh);
 538         if (unlikely(!is_valid_virt_queue_idx(queue_id, 0, dev->virt_qp_nb))) {
 539                 RTE_LOG(ERR, VHOST_DATA,
 540                         "%s (%"PRIu64"): virtqueue idx:%d invalid.\n",
 541                         __func__, dev->device_fh, queue_id);
 542                 return 0;
 543         }
 544
 545         vq = dev->virtqueue[queue_id];
 546         if (unlikely(vq->enabled == 0))
 547                 return 0;
 548
 549         count = RTE_MIN((uint32_t)MAX_PKT_BURST, count);
 550         if (count == 0)
 551                 return 0;
 552
 553         for (pkt_idx = 0; pkt_idx < count; pkt_idx++) {
 554                 uint32_t pkt_len = pkts[pkt_idx]->pkt_len + vq->vhost_hlen;
 555
 556                 if (unlikely(reserve_avail_buf_mergeable(vq, pkt_len,
 557                                                          &start, &end) < 0)) {
 558                         LOG_DEBUG(VHOST_DATA,
 559                                 "(%" PRIu64 ") Failed to get enough desc from vring\n",
 560                                 dev->device_fh);
 561                         break;
 562                 }
 563
 564                 nr_used = copy_mbuf_to_desc_mergeable(dev, vq, start, end,
 565                                                       pkts[pkt_idx]);
 566                 rte_smp_wmb();
 567
 568                 /*
 569                  * Wait until it's our turn to add our buffer
 570                  * to the used ring.
 571                  */
 572                 while (unlikely(vq->last_used_idx != start))
 573                         rte_pause();
 574
 575                 *(volatile uint16_t *)&vq->used->idx += nr_used;
 576                 vhost_log_used_vring(dev, vq, offsetof(struct vring_used, idx),
 577                         sizeof(vq->used->idx));
 578                 vq->last_used_idx = end;
 579         }
 580
 581         if (likely(pkt_idx)) {
 582                 /* flush used->idx update before we read avail->flags. */
 583                 rte_mb();
 584
 585                 /* Kick the guest if necessary. */
 586                 if (!(vq->avail->flags & VRING_AVAIL_F_NO_INTERRUPT)
 587                                 && (vq->callfd >= 0))
 588                         eventfd_write(vq->callfd, (eventfd_t)1);
 589         }
 590
 591         return pkt_idx;
 592 }
 593
 594 uint16_t
 595 rte_vhost_enqueue_burst(struct virtio_net *dev, uint16_t queue_id,
 596         struct rte_mbuf **pkts, uint16_t count)
 597 {
 598         if (dev->features & (1 << VIRTIO_NET_F_MRG_RXBUF))
 599                 return virtio_dev_merge_rx(dev, queue_id, pkts, count);
 600         else
 601                 return virtio_dev_rx(dev, queue_id, pkts, count);
 602 }
 603
 604 static void
 605 parse_ethernet(struct rte_mbuf *m, uint16_t *l4_proto, void **l4_hdr)
 606 {
 607         struct ipv4_hdr *ipv4_hdr;
 608         struct ipv6_hdr *ipv6_hdr;
 609         void *l3_hdr = NULL;
 610         struct ether_hdr *eth_hdr;
 611         uint16_t ethertype;
 612
 613         eth_hdr = rte_pktmbuf_mtod(m, struct ether_hdr *);
 614
 615         m->l2_len = sizeof(struct ether_hdr);
 616         ethertype = rte_be_to_cpu_16(eth_hdr->ether_type);
 617
 618         if (ethertype == ETHER_TYPE_VLAN) {
 619                 struct vlan_hdr *vlan_hdr = (struct vlan_hdr *)(eth_hdr + 1);
 620
 621                 m->l2_len += sizeof(struct vlan_hdr);
 622                 ethertype = rte_be_to_cpu_16(vlan_hdr->eth_proto);
 623         }
 624
 625         l3_hdr = (char *)eth_hdr + m->l2_len;
 626
 627         switch (ethertype) {
 628         case ETHER_TYPE_IPv4:
 629                 ipv4_hdr = (struct ipv4_hdr *)l3_hdr;
 630                 *l4_proto = ipv4_hdr->next_proto_id;
 631                 m->l3_len = (ipv4_hdr->version_ihl & 0x0f) * 4;
 632                 *l4_hdr = (char *)l3_hdr + m->l3_len;
 633                 m->ol_flags |= PKT_TX_IPV4;
 634                 break;
 635         case ETHER_TYPE_IPv6:
 636                 ipv6_hdr = (struct ipv6_hdr *)l3_hdr;
 637                 *l4_proto = ipv6_hdr->proto;
 638                 m->l3_len = sizeof(struct ipv6_hdr);
 639                 *l4_hdr = (char *)l3_hdr + m->l3_len;
 640                 m->ol_flags |= PKT_TX_IPV6;
 641                 break;
 642         default:
 643                 m->l3_len = 0;
 644                 *l4_proto = 0;
 645                 break;
 646         }
 647 }
 648
 649 static inline void __attribute__((always_inline))
 650 vhost_dequeue_offload(struct virtio_net_hdr *hdr, struct rte_mbuf *m)
 651 {
 652         uint16_t l4_proto = 0;
 653         void *l4_hdr = NULL;
 654         struct tcp_hdr *tcp_hdr = NULL;
 655
 656         parse_ethernet(m, &l4_proto, &l4_hdr);
 657         if (hdr->flags == VIRTIO_NET_HDR_F_NEEDS_CSUM) {
 658                 if (hdr->csum_start == (m->l2_len + m->l3_len)) {
 659                         switch (hdr->csum_offset) {
 660                         case (offsetof(struct tcp_hdr, cksum)):
 661                                 if (l4_proto == IPPROTO_TCP)
 662                                         m->ol_flags |= PKT_TX_TCP_CKSUM;
 663                                 break;
 664                         case (offsetof(struct udp_hdr, dgram_cksum)):
 665                                 if (l4_proto == IPPROTO_UDP)
 666                                         m->ol_flags |= PKT_TX_UDP_CKSUM;
 667                                 break;
 668                         case (offsetof(struct sctp_hdr, cksum)):
 669                                 if (l4_proto == IPPROTO_SCTP)
 670                                         m->ol_flags |= PKT_TX_SCTP_CKSUM;
 671                                 break;
 672                         default:
 673                                 break;
 674                         }
 675                 }
 676         }
 677
 678         if (hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) {
 679                 switch (hdr->gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
 680                 case VIRTIO_NET_HDR_GSO_TCPV4:
 681                 case VIRTIO_NET_HDR_GSO_TCPV6:
 682                         tcp_hdr = (struct tcp_hdr *)l4_hdr;
 683                         m->ol_flags |= PKT_TX_TCP_SEG;
 684                         m->tso_segsz = hdr->gso_size;
 685                         m->l4_len = (tcp_hdr->data_off & 0xf0) >> 2;
 686                         break;
 687                 default:
 688                         RTE_LOG(WARNING, VHOST_DATA,
 689                                 "unsupported gso type %u.\n", hdr->gso_type);
 690                         break;
 691                 }
 692         }
 693 }
 694
 695 #define RARP_PKT_SIZE   64
 696
 697 static int
 698 make_rarp_packet(struct rte_mbuf *rarp_mbuf, const struct ether_addr *mac)
 699 {
 700         struct ether_hdr *eth_hdr;
 701         struct arp_hdr  *rarp;
 702
 703         if (rarp_mbuf->buf_len < 64) {
 704                 RTE_LOG(WARNING, VHOST_DATA,
 705                         "failed to make RARP; mbuf size too small %u (< %d)\n",
 706                         rarp_mbuf->buf_len, RARP_PKT_SIZE);
 707                 return -1;
 708         }
 709
 710         /* Ethernet header. */
 711         eth_hdr = rte_pktmbuf_mtod_offset(rarp_mbuf, struct ether_hdr *, 0);
 712         memset(eth_hdr->d_addr.addr_bytes, 0xff, ETHER_ADDR_LEN);
 713         ether_addr_copy(mac, &eth_hdr->s_addr);
 714         eth_hdr->ether_type = htons(ETHER_TYPE_RARP);
 715
 716         /* RARP header. */
 717         rarp = (struct arp_hdr *)(eth_hdr + 1);
 718         rarp->arp_hrd = htons(ARP_HRD_ETHER);
 719         rarp->arp_pro = htons(ETHER_TYPE_IPv4);
 720         rarp->arp_hln = ETHER_ADDR_LEN;
 721         rarp->arp_pln = 4;
 722         rarp->arp_op  = htons(ARP_OP_REVREQUEST);
 723
 724         ether_addr_copy(mac, &rarp->arp_data.arp_sha);
 725         ether_addr_copy(mac, &rarp->arp_data.arp_tha);
 726         memset(&rarp->arp_data.arp_sip, 0x00, 4);
 727         memset(&rarp->arp_data.arp_tip, 0x00, 4);
 728
 729         rarp_mbuf->pkt_len  = rarp_mbuf->data_len = RARP_PKT_SIZE;
 730
 731         return 0;
 732 }
 733
 734 static inline int __attribute__((always_inline))
 735 copy_desc_to_mbuf(struct virtio_net *dev, struct vhost_virtqueue *vq,
 736                   struct rte_mbuf *m, uint16_t desc_idx,
 737                   struct rte_mempool *mbuf_pool)
 738 {
 739         struct vring_desc *desc;
 740         uint64_t desc_addr;
 741         uint32_t desc_avail, desc_offset;
 742         uint32_t mbuf_avail, mbuf_offset;
 743         uint32_t cpy_len;
 744         struct rte_mbuf *cur = m, *prev = m;
 745         struct virtio_net_hdr *hdr;
 746         /* A counter to avoid desc dead loop chain */
 747         uint32_t nr_desc = 1;
 748
 749         desc = &vq->desc[desc_idx];
 750         if (unlikely(desc->len < vq->vhost_hlen))
 751                 return -1;
 752
 753         desc_addr = gpa_to_vva(dev, desc->addr);
 754         rte_prefetch0((void *)(uintptr_t)desc_addr);
 755
 756         /* Retrieve virtio net header */
 757         hdr = (struct virtio_net_hdr *)((uintptr_t)desc_addr);
 758         desc_avail  = desc->len - vq->vhost_hlen;
 759         desc_offset = vq->vhost_hlen;
 760
 761         mbuf_offset = 0;
 762         mbuf_avail  = m->buf_len - RTE_PKTMBUF_HEADROOM;
 763         while (desc_avail != 0 || (desc->flags & VRING_DESC_F_NEXT) != 0) {
 764                 /* This desc reaches to its end, get the next one */
 765                 if (desc_avail == 0) {
 766                         if (unlikely(desc->next >= vq->size ||
 767                                      ++nr_desc >= vq->size))
 768                                 return -1;
 769                         desc = &vq->desc[desc->next];
 770
 771                         desc_addr = gpa_to_vva(dev, desc->addr);
 772                         rte_prefetch0((void *)(uintptr_t)desc_addr);
 773
 774                         desc_offset = 0;
 775                         desc_avail  = desc->len;
 776
 777                         PRINT_PACKET(dev, (uintptr_t)desc_addr, desc->len, 0);
 778                 }
 779
 780                 /*
 781                  * This mbuf reaches to its end, get a new one
 782                  * to hold more data.
 783                  */
 784                 if (mbuf_avail == 0) {
 785                         cur = rte_pktmbuf_alloc(mbuf_pool);
 786                         if (unlikely(cur == NULL)) {
 787                                 RTE_LOG(ERR, VHOST_DATA, "Failed to "
 788                                         "allocate memory for mbuf.\n");
 789                                 return -1;
 790                         }
 791
 792                         prev->next = cur;
 793                         prev->data_len = mbuf_offset;
 794                         m->nb_segs += 1;
 795                         m->pkt_len += mbuf_offset;
 796                         prev = cur;
 797
 798                         mbuf_offset = 0;
 799                         mbuf_avail  = cur->buf_len - RTE_PKTMBUF_HEADROOM;
 800                 }
 801
 802                 cpy_len = RTE_MIN(desc_avail, mbuf_avail);
 803                 rte_memcpy(rte_pktmbuf_mtod_offset(cur, void *, mbuf_offset),
 804                         (void *)((uintptr_t)(desc_addr + desc_offset)),
 805                         cpy_len);
 806
 807                 mbuf_avail  -= cpy_len;
 808                 mbuf_offset += cpy_len;
 809                 desc_avail  -= cpy_len;
 810                 desc_offset += cpy_len;
 811         }
 812
 813         prev->data_len = mbuf_offset;
 814         m->pkt_len    += mbuf_offset;
 815
 816         if (hdr->flags != 0 || hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE)
 817                 vhost_dequeue_offload(hdr, m);
 818
 819         return 0;
 820 }
 821
 822 uint16_t
 823 rte_vhost_dequeue_burst(struct virtio_net *dev, uint16_t queue_id,
 824         struct rte_mempool *mbuf_pool, struct rte_mbuf **pkts, uint16_t count)
 825 {
 826         struct rte_mbuf *rarp_mbuf = NULL;
 827         struct vhost_virtqueue *vq;
 828         uint32_t desc_indexes[MAX_PKT_BURST];
 829         uint32_t used_idx;
 830         uint32_t i = 0;
 831         uint16_t free_entries;
 832         uint16_t avail_idx;
 833
 834         if (unlikely(!is_valid_virt_queue_idx(queue_id, 1, dev->virt_qp_nb))) {
 835                 RTE_LOG(ERR, VHOST_DATA,
 836                         "%s (%"PRIu64"): virtqueue idx:%d invalid.\n",
 837                         __func__, dev->device_fh, queue_id);
 838                 return 0;
 839         }
 840
 841         vq = dev->virtqueue[queue_id];
 842         if (unlikely(vq->enabled == 0))
 843                 return 0;
 844
 845         /*
 846          * Construct a RARP broadcast packet, and inject it to the "pkts"
 847          * array, to looks like that guest actually send such packet.
 848          *
 849          * Check user_send_rarp() for more information.
 850          */
 851         if (unlikely(rte_atomic16_cmpset((volatile uint16_t *)
 852                                          &dev->broadcast_rarp.cnt, 1, 0))) {
 853                 rarp_mbuf = rte_pktmbuf_alloc(mbuf_pool);
 854                 if (rarp_mbuf == NULL) {
 855                         RTE_LOG(ERR, VHOST_DATA,
 856                                 "Failed to allocate memory for mbuf.\n");
 857                         return 0;
 858                 }
 859
 860                 if (make_rarp_packet(rarp_mbuf, &dev->mac)) {
 861                         rte_pktmbuf_free(rarp_mbuf);
 862                         rarp_mbuf = NULL;
 863                 } else {
 864                         count -= 1;
 865                 }
 866         }
 867
 868         avail_idx =  *((volatile uint16_t *)&vq->avail->idx);
 869         free_entries = avail_idx - vq->last_used_idx;
 870         if (free_entries == 0)
 871                 goto out;
 872
 873         LOG_DEBUG(VHOST_DATA, "%s (%"PRIu64")\n", __func__, dev->device_fh);
 874
 875         /* Prefetch available ring to retrieve head indexes. */
 876         used_idx = vq->last_used_idx & (vq->size - 1);
 877         rte_prefetch0(&vq->avail->ring[used_idx]);
 878
 879         count = RTE_MIN(count, MAX_PKT_BURST);
 880         count = RTE_MIN(count, free_entries);
 881         LOG_DEBUG(VHOST_DATA, "(%"PRIu64") about to dequeue %u buffers\n",
 882                         dev->device_fh, count);
 883
 884         /* Retrieve all of the head indexes first to avoid caching issues. */
 885         for (i = 0; i < count; i++) {
 886                 desc_indexes[i] = vq->avail->ring[(vq->last_used_idx + i) &
 887                                         (vq->size - 1)];
 888         }
 889
 890         /* Prefetch descriptor index. */
 891         rte_prefetch0(&vq->desc[desc_indexes[0]]);
 892         rte_prefetch0(&vq->used->ring[vq->last_used_idx & (vq->size - 1)]);
 893
 894         for (i = 0; i < count; i++) {
 895                 int err;
 896
 897                 if (likely(i + 1 < count)) {
 898                         rte_prefetch0(&vq->desc[desc_indexes[i + 1]]);
 899                         rte_prefetch0(&vq->used->ring[(used_idx + 1) &
 900                                                       (vq->size - 1)]);
 901                 }
 902
 903                 pkts[i] = rte_pktmbuf_alloc(mbuf_pool);
 904                 if (unlikely(pkts[i] == NULL)) {
 905                         RTE_LOG(ERR, VHOST_DATA,
 906                                 "Failed to allocate memory for mbuf.\n");
 907                         break;
 908                 }
 909                 err = copy_desc_to_mbuf(dev, vq, pkts[i], desc_indexes[i],
 910                                         mbuf_pool);
 911                 if (unlikely(err)) {
 912                         rte_pktmbuf_free(pkts[i]);
 913                         break;
 914                 }
 915
 916                 used_idx = vq->last_used_idx++ & (vq->size - 1);
 917                 vq->used->ring[used_idx].id  = desc_indexes[i];
 918                 vq->used->ring[used_idx].len = 0;
 919                 vhost_log_used_vring(dev, vq,
 920                                 offsetof(struct vring_used, ring[used_idx]),
 921                                 sizeof(vq->used->ring[used_idx]));
 922         }
 923
 924         rte_smp_wmb();
 925         rte_smp_rmb();
 926         vq->used->idx += i;
 927         vhost_log_used_vring(dev, vq, offsetof(struct vring_used, idx),
 928                         sizeof(vq->used->idx));
 929
 930         /* Kick guest if required. */
 931         if (!(vq->avail->flags & VRING_AVAIL_F_NO_INTERRUPT)
 932                         && (vq->callfd >= 0))
 933                 eventfd_write(vq->callfd, (eventfd_t)1);
 934
 935 out:
 936         if (unlikely(rarp_mbuf != NULL)) {
 937                 /*
 938                  * Inject it to the head of "pkts" array, so that switch's mac
 939                  * learning table will get updated first.
 940                  */
 941                 memmove(&pkts[1], pkts, i * sizeof(struct rte_mbuf *));
 942                 pkts[0] = rarp_mbuf;
 943                 i += 1;
 944         }
 945
 946         return i;
 947 }