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         memset(net_hdr, 0, sizeof(struct virtio_net_hdr));
  98
  99         if (m_buf->ol_flags & PKT_TX_L4_MASK) {
 100                 net_hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
 101                 net_hdr->csum_start = m_buf->l2_len + m_buf->l3_len;
 102
 103                 switch (m_buf->ol_flags & PKT_TX_L4_MASK) {
 104                 case PKT_TX_TCP_CKSUM:
 105                         net_hdr->csum_offset = (offsetof(struct tcp_hdr,
 106                                                 cksum));
 107                         break;
 108                 case PKT_TX_UDP_CKSUM:
 109                         net_hdr->csum_offset = (offsetof(struct udp_hdr,
 110                                                 dgram_cksum));
 111                         break;
 112                 case PKT_TX_SCTP_CKSUM:
 113                         net_hdr->csum_offset = (offsetof(struct sctp_hdr,
 114                                                 cksum));
 115                         break;
 116                 }
 117         }
 118
 119         if (m_buf->ol_flags & PKT_TX_TCP_SEG) {
 120                 if (m_buf->ol_flags & PKT_TX_IPV4)
 121                         net_hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
 122                 else
 123                         net_hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
 124                 net_hdr->gso_size = m_buf->tso_segsz;
 125                 net_hdr->hdr_len = m_buf->l2_len + m_buf->l3_len
 126                                         + m_buf->l4_len;
 127         }
 128
 129         return;
 130 }
 131
 132 /**
 133  * This function adds buffers to the virtio devices RX virtqueue. Buffers can
 134  * be received from the physical port or from another virtio device. A packet
 135  * count is returned to indicate the number of packets that are succesfully
 136  * added to the RX queue. This function works when the mbuf is scattered, but
 137  * it doesn't support the mergeable feature.
 138  */
 139 static inline uint32_t __attribute__((always_inline))
 140 virtio_dev_rx(struct virtio_net *dev, uint16_t queue_id,
 141         struct rte_mbuf **pkts, uint32_t count)
 142 {
 143         struct vhost_virtqueue *vq;
 144         struct vring_desc *desc, *hdr_desc;
 145         struct rte_mbuf *buff, *first_buff;
 146         /* The virtio_hdr is initialised to 0. */
 147         struct virtio_net_hdr_mrg_rxbuf virtio_hdr = {{0, 0, 0, 0, 0, 0}, 0};
 148         uint64_t buff_addr = 0;
 149         uint64_t buff_hdr_addr = 0;
 150         uint32_t head[MAX_PKT_BURST];
 151         uint32_t head_idx, packet_success = 0;
 152         uint16_t avail_idx, res_cur_idx;
 153         uint16_t res_base_idx, res_end_idx;
 154         uint16_t free_entries;
 155         uint8_t success = 0;
 156
 157         LOG_DEBUG(VHOST_DATA, "(%"PRIu64") virtio_dev_rx()\n", dev->device_fh);
 158         if (unlikely(!is_valid_virt_queue_idx(queue_id, 0, dev->virt_qp_nb))) {
 159                 RTE_LOG(ERR, VHOST_DATA,
 160                         "%s (%"PRIu64"): virtqueue idx:%d invalid.\n",
 161                         __func__, dev->device_fh, queue_id);
 162                 return 0;
 163         }
 164
 165         vq = dev->virtqueue[queue_id];
 166         if (unlikely(vq->enabled == 0))
 167                 return 0;
 168
 169         count = (count > MAX_PKT_BURST) ? MAX_PKT_BURST : count;
 170
 171         /*
 172          * As many data cores may want access to available buffers,
 173          * they need to be reserved.
 174          */
 175         do {
 176                 res_base_idx = vq->last_used_idx_res;
 177                 avail_idx = *((volatile uint16_t *)&vq->avail->idx);
 178
 179                 free_entries = (avail_idx - res_base_idx);
 180                 /*check that we have enough buffers*/
 181                 if (unlikely(count > free_entries))
 182                         count = free_entries;
 183
 184                 if (count == 0)
 185                         return 0;
 186
 187                 res_end_idx = res_base_idx + count;
 188                 /* vq->last_used_idx_res is atomically updated. */
 189                 /* TODO: Allow to disable cmpset if no concurrency in application. */
 190                 success = rte_atomic16_cmpset(&vq->last_used_idx_res,
 191                                 res_base_idx, res_end_idx);
 192         } while (unlikely(success == 0));
 193         res_cur_idx = res_base_idx;
 194         LOG_DEBUG(VHOST_DATA, "(%"PRIu64") Current Index %d| End Index %d\n",
 195                         dev->device_fh, res_cur_idx, res_end_idx);
 196
 197         /* Prefetch available ring to retrieve indexes. */
 198         rte_prefetch0(&vq->avail->ring[res_cur_idx & (vq->size - 1)]);
 199
 200         /* Retrieve all of the head indexes first to avoid caching issues. */
 201         for (head_idx = 0; head_idx < count; head_idx++)
 202                 head[head_idx] = vq->avail->ring[(res_cur_idx + head_idx) &
 203                                         (vq->size - 1)];
 204
 205         /*Prefetch descriptor index. */
 206         rte_prefetch0(&vq->desc[head[packet_success]]);
 207
 208         while (res_cur_idx != res_end_idx) {
 209                 uint32_t offset = 0, vb_offset = 0;
 210                 uint32_t pkt_len, len_to_cpy, data_len, total_copied = 0;
 211                 uint8_t hdr = 0, uncompleted_pkt = 0;
 212                 uint16_t idx;
 213
 214                 /* Get descriptor from available ring */
 215                 desc = &vq->desc[head[packet_success]];
 216
 217                 buff = pkts[packet_success];
 218                 first_buff = buff;
 219
 220                 /* Convert from gpa to vva (guest physical addr -> vhost virtual addr) */
 221                 buff_addr = gpa_to_vva(dev, desc->addr);
 222                 /* Prefetch buffer address. */
 223                 rte_prefetch0((void *)(uintptr_t)buff_addr);
 224
 225                 /* Copy virtio_hdr to packet and increment buffer address */
 226                 buff_hdr_addr = buff_addr;
 227                 hdr_desc = desc;
 228
 229                 /*
 230                  * If the descriptors are chained the header and data are
 231                  * placed in separate buffers.
 232                  */
 233                 if ((desc->flags & VRING_DESC_F_NEXT) &&
 234                         (desc->len == vq->vhost_hlen)) {
 235                         desc = &vq->desc[desc->next];
 236                         /* Buffer address translation. */
 237                         buff_addr = gpa_to_vva(dev, desc->addr);
 238                 } else {
 239                         vb_offset += vq->vhost_hlen;
 240                         hdr = 1;
 241                 }
 242
 243                 pkt_len = rte_pktmbuf_pkt_len(buff);
 244                 data_len = rte_pktmbuf_data_len(buff);
 245                 len_to_cpy = RTE_MIN(data_len,
 246                         hdr ? desc->len - vq->vhost_hlen : desc->len);
 247                 while (total_copied < pkt_len) {
 248                         /* Copy mbuf data to buffer */
 249                         rte_memcpy((void *)(uintptr_t)(buff_addr + vb_offset),
 250                                 rte_pktmbuf_mtod_offset(buff, const void *, offset),
 251                                 len_to_cpy);
 252                         vhost_log_write(dev, desc->addr + vb_offset, len_to_cpy);
 253                         PRINT_PACKET(dev, (uintptr_t)(buff_addr + vb_offset),
 254                                 len_to_cpy, 0);
 255
 256                         offset += len_to_cpy;
 257                         vb_offset += len_to_cpy;
 258                         total_copied += len_to_cpy;
 259
 260                         /* The whole packet completes */
 261                         if (total_copied == pkt_len)
 262                                 break;
 263
 264                         /* The current segment completes */
 265                         if (offset == data_len) {
 266                                 buff = buff->next;
 267                                 offset = 0;
 268                                 data_len = rte_pktmbuf_data_len(buff);
 269                         }
 270
 271                         /* The current vring descriptor done */
 272                         if (vb_offset == desc->len) {
 273                                 if (desc->flags & VRING_DESC_F_NEXT) {
 274                                         desc = &vq->desc[desc->next];
 275                                         buff_addr = gpa_to_vva(dev, desc->addr);
 276                                         vb_offset = 0;
 277                                 } else {
 278                                         /* Room in vring buffer is not enough */
 279                                         uncompleted_pkt = 1;
 280                                         break;
 281                                 }
 282                         }
 283                         len_to_cpy = RTE_MIN(data_len - offset, desc->len - vb_offset);
 284                 }
 285
 286                 /* Update used ring with desc information */
 287                 idx = res_cur_idx & (vq->size - 1);
 288                 vq->used->ring[idx].id = head[packet_success];
 289
 290                 /* Drop the packet if it is uncompleted */
 291                 if (unlikely(uncompleted_pkt == 1))
 292                         vq->used->ring[idx].len = vq->vhost_hlen;
 293                 else
 294                         vq->used->ring[idx].len = pkt_len + vq->vhost_hlen;
 295
 296                 vhost_log_used_vring(dev, vq,
 297                         offsetof(struct vring_used, ring[idx]),
 298                         sizeof(vq->used->ring[idx]));
 299
 300                 res_cur_idx++;
 301                 packet_success++;
 302
 303                 if (unlikely(uncompleted_pkt == 1))
 304                         continue;
 305
 306                 virtio_enqueue_offload(first_buff, &virtio_hdr.hdr);
 307
 308                 rte_memcpy((void *)(uintptr_t)buff_hdr_addr,
 309                         (const void *)&virtio_hdr, vq->vhost_hlen);
 310                 vhost_log_write(dev, hdr_desc->addr, vq->vhost_hlen);
 311
 312                 PRINT_PACKET(dev, (uintptr_t)buff_hdr_addr, vq->vhost_hlen, 1);
 313
 314                 if (res_cur_idx < res_end_idx) {
 315                         /* Prefetch descriptor index. */
 316                         rte_prefetch0(&vq->desc[head[packet_success]]);
 317                 }
 318         }
 319
 320         rte_compiler_barrier();
 321
 322         /* Wait until it's our turn to add our buffer to the used ring. */
 323         while (unlikely(vq->last_used_idx != res_base_idx))
 324                 rte_pause();
 325
 326         *(volatile uint16_t *)&vq->used->idx += count;
 327         vq->last_used_idx = res_end_idx;
 328         vhost_log_used_vring(dev, vq,
 329                 offsetof(struct vring_used, idx),
 330                 sizeof(vq->used->idx));
 331
 332         /* flush used->idx update before we read avail->flags. */
 333         rte_mb();
 334
 335         /* Kick the guest if necessary. */
 336         if (!(vq->avail->flags & VRING_AVAIL_F_NO_INTERRUPT))
 337                 eventfd_write(vq->callfd, (eventfd_t)1);
 338         return count;
 339 }
 340
 341 static inline uint32_t __attribute__((always_inline))
 342 copy_from_mbuf_to_vring(struct virtio_net *dev, uint32_t queue_id,
 343                         uint16_t res_base_idx, uint16_t res_end_idx,
 344                         struct rte_mbuf *pkt)
 345 {
 346         uint32_t vec_idx = 0;
 347         uint32_t entry_success = 0;
 348         struct vhost_virtqueue *vq;
 349         /* The virtio_hdr is initialised to 0. */
 350         struct virtio_net_hdr_mrg_rxbuf virtio_hdr = {
 351                 {0, 0, 0, 0, 0, 0}, 0};
 352         uint16_t cur_idx = res_base_idx;
 353         uint64_t vb_addr = 0;
 354         uint64_t vb_hdr_addr = 0;
 355         uint32_t seg_offset = 0;
 356         uint32_t vb_offset = 0;
 357         uint32_t seg_avail;
 358         uint32_t vb_avail;
 359         uint32_t cpy_len, entry_len;
 360         uint16_t idx;
 361
 362         if (pkt == NULL)
 363                 return 0;
 364
 365         LOG_DEBUG(VHOST_DATA, "(%"PRIu64") Current Index %d| "
 366                 "End Index %d\n",
 367                 dev->device_fh, cur_idx, res_end_idx);
 368
 369         /*
 370          * Convert from gpa to vva
 371          * (guest physical addr -> vhost virtual addr)
 372          */
 373         vq = dev->virtqueue[queue_id];
 374
 375         vb_addr = gpa_to_vva(dev, vq->buf_vec[vec_idx].buf_addr);
 376         vb_hdr_addr = vb_addr;
 377
 378         /* Prefetch buffer address. */
 379         rte_prefetch0((void *)(uintptr_t)vb_addr);
 380
 381         virtio_hdr.num_buffers = res_end_idx - res_base_idx;
 382
 383         LOG_DEBUG(VHOST_DATA, "(%"PRIu64") RX: Num merge buffers %d\n",
 384                 dev->device_fh, virtio_hdr.num_buffers);
 385
 386         virtio_enqueue_offload(pkt, &virtio_hdr.hdr);
 387
 388         rte_memcpy((void *)(uintptr_t)vb_hdr_addr,
 389                 (const void *)&virtio_hdr, vq->vhost_hlen);
 390         vhost_log_write(dev, vq->buf_vec[vec_idx].buf_addr, vq->vhost_hlen);
 391
 392         PRINT_PACKET(dev, (uintptr_t)vb_hdr_addr, vq->vhost_hlen, 1);
 393
 394         seg_avail = rte_pktmbuf_data_len(pkt);
 395         vb_offset = vq->vhost_hlen;
 396         vb_avail = vq->buf_vec[vec_idx].buf_len - vq->vhost_hlen;
 397
 398         entry_len = vq->vhost_hlen;
 399
 400         if (vb_avail == 0) {
 401                 uint32_t desc_idx = vq->buf_vec[vec_idx].desc_idx;
 402
 403                 if ((vq->desc[desc_idx].flags & VRING_DESC_F_NEXT) == 0) {
 404                         idx = cur_idx & (vq->size - 1);
 405
 406                         /* Update used ring with desc information */
 407                         vq->used->ring[idx].id = vq->buf_vec[vec_idx].desc_idx;
 408                         vq->used->ring[idx].len = entry_len;
 409
 410                         vhost_log_used_vring(dev, vq,
 411                                         offsetof(struct vring_used, ring[idx]),
 412                                         sizeof(vq->used->ring[idx]));
 413
 414                         entry_len = 0;
 415                         cur_idx++;
 416                         entry_success++;
 417                 }
 418
 419                 vec_idx++;
 420                 vb_addr = gpa_to_vva(dev, vq->buf_vec[vec_idx].buf_addr);
 421
 422                 /* Prefetch buffer address. */
 423                 rte_prefetch0((void *)(uintptr_t)vb_addr);
 424                 vb_offset = 0;
 425                 vb_avail = vq->buf_vec[vec_idx].buf_len;
 426         }
 427
 428         cpy_len = RTE_MIN(vb_avail, seg_avail);
 429
 430         while (cpy_len > 0) {
 431                 /* Copy mbuf data to vring buffer */
 432                 rte_memcpy((void *)(uintptr_t)(vb_addr + vb_offset),
 433                         rte_pktmbuf_mtod_offset(pkt, const void *, seg_offset),
 434                         cpy_len);
 435                 vhost_log_write(dev, vq->buf_vec[vec_idx].buf_addr + vb_offset,
 436                         cpy_len);
 437
 438                 PRINT_PACKET(dev,
 439                         (uintptr_t)(vb_addr + vb_offset),
 440                         cpy_len, 0);
 441
 442                 seg_offset += cpy_len;
 443                 vb_offset += cpy_len;
 444                 seg_avail -= cpy_len;
 445                 vb_avail -= cpy_len;
 446                 entry_len += cpy_len;
 447
 448                 if (seg_avail != 0) {
 449                         /*
 450                          * The virtio buffer in this vring
 451                          * entry reach to its end.
 452                          * But the segment doesn't complete.
 453                          */
 454                         if ((vq->desc[vq->buf_vec[vec_idx].desc_idx].flags &
 455                                 VRING_DESC_F_NEXT) == 0) {
 456                                 /* Update used ring with desc information */
 457                                 idx = cur_idx & (vq->size - 1);
 458                                 vq->used->ring[idx].id
 459                                         = vq->buf_vec[vec_idx].desc_idx;
 460                                 vq->used->ring[idx].len = entry_len;
 461                                 vhost_log_used_vring(dev, vq,
 462                                         offsetof(struct vring_used, ring[idx]),
 463                                         sizeof(vq->used->ring[idx]));
 464                                 entry_len = 0;
 465                                 cur_idx++;
 466                                 entry_success++;
 467                         }
 468
 469                         vec_idx++;
 470                         vb_addr = gpa_to_vva(dev,
 471                                 vq->buf_vec[vec_idx].buf_addr);
 472                         vb_offset = 0;
 473                         vb_avail = vq->buf_vec[vec_idx].buf_len;
 474                         cpy_len = RTE_MIN(vb_avail, seg_avail);
 475                 } else {
 476                         /*
 477                          * This current segment complete, need continue to
 478                          * check if the whole packet complete or not.
 479                          */
 480                         pkt = pkt->next;
 481                         if (pkt != NULL) {
 482                                 /*
 483                                  * There are more segments.
 484                                  */
 485                                 if (vb_avail == 0) {
 486                                         /*
 487                                          * This current buffer from vring is
 488                                          * used up, need fetch next buffer
 489                                          * from buf_vec.
 490                                          */
 491                                         uint32_t desc_idx =
 492                                                 vq->buf_vec[vec_idx].desc_idx;
 493
 494                                         if ((vq->desc[desc_idx].flags &
 495                                                 VRING_DESC_F_NEXT) == 0) {
 496                                                 idx = cur_idx & (vq->size - 1);
 497                                                 /*
 498                                                  * Update used ring with the
 499                                                  * descriptor information
 500                                                  */
 501                                                 vq->used->ring[idx].id
 502                                                         = desc_idx;
 503                                                 vq->used->ring[idx].len
 504                                                         = entry_len;
 505                                                 vhost_log_used_vring(dev, vq,
 506                                                         offsetof(struct vring_used, ring[idx]),
 507                                                         sizeof(vq->used->ring[idx]));
 508                                                 entry_success++;
 509                                                 entry_len = 0;
 510                                                 cur_idx++;
 511                                         }
 512
 513                                         /* Get next buffer from buf_vec. */
 514                                         vec_idx++;
 515                                         vb_addr = gpa_to_vva(dev,
 516                                                 vq->buf_vec[vec_idx].buf_addr);
 517                                         vb_avail =
 518                                                 vq->buf_vec[vec_idx].buf_len;
 519                                         vb_offset = 0;
 520                                 }
 521
 522                                 seg_offset = 0;
 523                                 seg_avail = rte_pktmbuf_data_len(pkt);
 524                                 cpy_len = RTE_MIN(vb_avail, seg_avail);
 525                         } else {
 526                                 /*
 527                                  * This whole packet completes.
 528                                  */
 529                                 /* Update used ring with desc information */
 530                                 idx = cur_idx & (vq->size - 1);
 531                                 vq->used->ring[idx].id
 532                                         = vq->buf_vec[vec_idx].desc_idx;
 533                                 vq->used->ring[idx].len = entry_len;
 534                                 vhost_log_used_vring(dev, vq,
 535                                         offsetof(struct vring_used, ring[idx]),
 536                                         sizeof(vq->used->ring[idx]));
 537                                 entry_success++;
 538                                 break;
 539                         }
 540                 }
 541         }
 542
 543         return entry_success;
 544 }
 545
 546 static inline void __attribute__((always_inline))
 547 update_secure_len(struct vhost_virtqueue *vq, uint32_t id,
 548         uint32_t *secure_len, uint32_t *vec_idx)
 549 {
 550         uint16_t wrapped_idx = id & (vq->size - 1);
 551         uint32_t idx = vq->avail->ring[wrapped_idx];
 552         uint8_t next_desc;
 553         uint32_t len = *secure_len;
 554         uint32_t vec_id = *vec_idx;
 555
 556         do {
 557                 next_desc = 0;
 558                 len += vq->desc[idx].len;
 559                 vq->buf_vec[vec_id].buf_addr = vq->desc[idx].addr;
 560                 vq->buf_vec[vec_id].buf_len = vq->desc[idx].len;
 561                 vq->buf_vec[vec_id].desc_idx = idx;
 562                 vec_id++;
 563
 564                 if (vq->desc[idx].flags & VRING_DESC_F_NEXT) {
 565                         idx = vq->desc[idx].next;
 566                         next_desc = 1;
 567                 }
 568         } while (next_desc);
 569
 570         *secure_len = len;
 571         *vec_idx = vec_id;
 572 }
 573
 574 /*
 575  * This function works for mergeable RX.
 576  */
 577 static inline uint32_t __attribute__((always_inline))
 578 virtio_dev_merge_rx(struct virtio_net *dev, uint16_t queue_id,
 579         struct rte_mbuf **pkts, uint32_t count)
 580 {
 581         struct vhost_virtqueue *vq;
 582         uint32_t pkt_idx = 0, entry_success = 0;
 583         uint16_t avail_idx;
 584         uint16_t res_base_idx, res_cur_idx;
 585         uint8_t success = 0;
 586
 587         LOG_DEBUG(VHOST_DATA, "(%"PRIu64") virtio_dev_merge_rx()\n",
 588                 dev->device_fh);
 589         if (unlikely(!is_valid_virt_queue_idx(queue_id, 0, dev->virt_qp_nb))) {
 590                 RTE_LOG(ERR, VHOST_DATA,
 591                         "%s (%"PRIu64"): virtqueue idx:%d invalid.\n",
 592                         __func__, dev->device_fh, queue_id);
 593                 return 0;
 594         }
 595
 596         vq = dev->virtqueue[queue_id];
 597         if (unlikely(vq->enabled == 0))
 598                 return 0;
 599
 600         count = RTE_MIN((uint32_t)MAX_PKT_BURST, count);
 601
 602         if (count == 0)
 603                 return 0;
 604
 605         for (pkt_idx = 0; pkt_idx < count; pkt_idx++) {
 606                 uint32_t pkt_len = pkts[pkt_idx]->pkt_len + vq->vhost_hlen;
 607
 608                 do {
 609                         /*
 610                          * As many data cores may want access to available
 611                          * buffers, they need to be reserved.
 612                          */
 613                         uint32_t secure_len = 0;
 614                         uint32_t vec_idx = 0;
 615
 616                         res_base_idx = vq->last_used_idx_res;
 617                         res_cur_idx = res_base_idx;
 618
 619                         do {
 620                                 avail_idx = *((volatile uint16_t *)&vq->avail->idx);
 621                                 if (unlikely(res_cur_idx == avail_idx))
 622                                         goto merge_rx_exit;
 623
 624                                 update_secure_len(vq, res_cur_idx,
 625                                                   &secure_len, &vec_idx);
 626                                 res_cur_idx++;
 627                         } while (pkt_len > secure_len);
 628
 629                         /* vq->last_used_idx_res is atomically updated. */
 630                         success = rte_atomic16_cmpset(&vq->last_used_idx_res,
 631                                                         res_base_idx,
 632                                                         res_cur_idx);
 633                 } while (success == 0);
 634
 635                 entry_success = copy_from_mbuf_to_vring(dev, queue_id,
 636                         res_base_idx, res_cur_idx, pkts[pkt_idx]);
 637
 638                 rte_compiler_barrier();
 639
 640                 /*
 641                  * Wait until it's our turn to add our buffer
 642                  * to the used ring.
 643                  */
 644                 while (unlikely(vq->last_used_idx != res_base_idx))
 645                         rte_pause();
 646
 647                 *(volatile uint16_t *)&vq->used->idx += entry_success;
 648                 vq->last_used_idx = res_cur_idx;
 649         }
 650
 651 merge_rx_exit:
 652         if (likely(pkt_idx)) {
 653                 /* flush used->idx update before we read avail->flags. */
 654                 rte_mb();
 655
 656                 /* Kick the guest if necessary. */
 657                 if (!(vq->avail->flags & VRING_AVAIL_F_NO_INTERRUPT))
 658                         eventfd_write(vq->callfd, (eventfd_t)1);
 659         }
 660
 661         return pkt_idx;
 662 }
 663
 664 uint16_t
 665 rte_vhost_enqueue_burst(struct virtio_net *dev, uint16_t queue_id,
 666         struct rte_mbuf **pkts, uint16_t count)
 667 {
 668         if (unlikely(dev->features & (1 << VIRTIO_NET_F_MRG_RXBUF)))
 669                 return virtio_dev_merge_rx(dev, queue_id, pkts, count);
 670         else
 671                 return virtio_dev_rx(dev, queue_id, pkts, count);
 672 }
 673
 674 static void
 675 parse_ethernet(struct rte_mbuf *m, uint16_t *l4_proto, void **l4_hdr)
 676 {
 677         struct ipv4_hdr *ipv4_hdr;
 678         struct ipv6_hdr *ipv6_hdr;
 679         void *l3_hdr = NULL;
 680         struct ether_hdr *eth_hdr;
 681         uint16_t ethertype;
 682
 683         eth_hdr = rte_pktmbuf_mtod(m, struct ether_hdr *);
 684
 685         m->l2_len = sizeof(struct ether_hdr);
 686         ethertype = rte_be_to_cpu_16(eth_hdr->ether_type);
 687
 688         if (ethertype == ETHER_TYPE_VLAN) {
 689                 struct vlan_hdr *vlan_hdr = (struct vlan_hdr *)(eth_hdr + 1);
 690
 691                 m->l2_len += sizeof(struct vlan_hdr);
 692                 ethertype = rte_be_to_cpu_16(vlan_hdr->eth_proto);
 693         }
 694
 695         l3_hdr = (char *)eth_hdr + m->l2_len;
 696
 697         switch (ethertype) {
 698         case ETHER_TYPE_IPv4:
 699                 ipv4_hdr = (struct ipv4_hdr *)l3_hdr;
 700                 *l4_proto = ipv4_hdr->next_proto_id;
 701                 m->l3_len = (ipv4_hdr->version_ihl & 0x0f) * 4;
 702                 *l4_hdr = (char *)l3_hdr + m->l3_len;
 703                 m->ol_flags |= PKT_TX_IPV4;
 704                 break;
 705         case ETHER_TYPE_IPv6:
 706                 ipv6_hdr = (struct ipv6_hdr *)l3_hdr;
 707                 *l4_proto = ipv6_hdr->proto;
 708                 m->l3_len = sizeof(struct ipv6_hdr);
 709                 *l4_hdr = (char *)l3_hdr + m->l3_len;
 710                 m->ol_flags |= PKT_TX_IPV6;
 711                 break;
 712         default:
 713                 m->l3_len = 0;
 714                 *l4_proto = 0;
 715                 break;
 716         }
 717 }
 718
 719 static inline void __attribute__((always_inline))
 720 vhost_dequeue_offload(struct virtio_net_hdr *hdr, struct rte_mbuf *m)
 721 {
 722         uint16_t l4_proto = 0;
 723         void *l4_hdr = NULL;
 724         struct tcp_hdr *tcp_hdr = NULL;
 725
 726         parse_ethernet(m, &l4_proto, &l4_hdr);
 727         if (hdr->flags == VIRTIO_NET_HDR_F_NEEDS_CSUM) {
 728                 if (hdr->csum_start == (m->l2_len + m->l3_len)) {
 729                         switch (hdr->csum_offset) {
 730                         case (offsetof(struct tcp_hdr, cksum)):
 731                                 if (l4_proto == IPPROTO_TCP)
 732                                         m->ol_flags |= PKT_TX_TCP_CKSUM;
 733                                 break;
 734                         case (offsetof(struct udp_hdr, dgram_cksum)):
 735                                 if (l4_proto == IPPROTO_UDP)
 736                                         m->ol_flags |= PKT_TX_UDP_CKSUM;
 737                                 break;
 738                         case (offsetof(struct sctp_hdr, cksum)):
 739                                 if (l4_proto == IPPROTO_SCTP)
 740                                         m->ol_flags |= PKT_TX_SCTP_CKSUM;
 741                                 break;
 742                         default:
 743                                 break;
 744                         }
 745                 }
 746         }
 747
 748         if (hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) {
 749                 switch (hdr->gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
 750                 case VIRTIO_NET_HDR_GSO_TCPV4:
 751                 case VIRTIO_NET_HDR_GSO_TCPV6:
 752                         tcp_hdr = (struct tcp_hdr *)l4_hdr;
 753                         m->ol_flags |= PKT_TX_TCP_SEG;
 754                         m->tso_segsz = hdr->gso_size;
 755                         m->l4_len = (tcp_hdr->data_off & 0xf0) >> 2;
 756                         break;
 757                 default:
 758                         RTE_LOG(WARNING, VHOST_DATA,
 759                                 "unsupported gso type %u.\n", hdr->gso_type);
 760                         break;
 761                 }
 762         }
 763 }
 764
 765 #define RARP_PKT_SIZE   64
 766
 767 static int
 768 make_rarp_packet(struct rte_mbuf *rarp_mbuf, const struct ether_addr *mac)
 769 {
 770         struct ether_hdr *eth_hdr;
 771         struct arp_hdr  *rarp;
 772
 773         if (rarp_mbuf->buf_len < 64) {
 774                 RTE_LOG(WARNING, VHOST_DATA,
 775                         "failed to make RARP; mbuf size too small %u (< %d)\n",
 776                         rarp_mbuf->buf_len, RARP_PKT_SIZE);
 777                 return -1;
 778         }
 779
 780         /* Ethernet header. */
 781         eth_hdr = rte_pktmbuf_mtod_offset(rarp_mbuf, struct ether_hdr *, 0);
 782         memset(eth_hdr->d_addr.addr_bytes, 0xff, ETHER_ADDR_LEN);
 783         ether_addr_copy(mac, &eth_hdr->s_addr);
 784         eth_hdr->ether_type = htons(ETHER_TYPE_RARP);
 785
 786         /* RARP header. */
 787         rarp = (struct arp_hdr *)(eth_hdr + 1);
 788         rarp->arp_hrd = htons(ARP_HRD_ETHER);
 789         rarp->arp_pro = htons(ETHER_TYPE_IPv4);
 790         rarp->arp_hln = ETHER_ADDR_LEN;
 791         rarp->arp_pln = 4;
 792         rarp->arp_op  = htons(ARP_OP_REVREQUEST);
 793
 794         ether_addr_copy(mac, &rarp->arp_data.arp_sha);
 795         ether_addr_copy(mac, &rarp->arp_data.arp_tha);
 796         memset(&rarp->arp_data.arp_sip, 0x00, 4);
 797         memset(&rarp->arp_data.arp_tip, 0x00, 4);
 798
 799         rarp_mbuf->pkt_len  = rarp_mbuf->data_len = RARP_PKT_SIZE;
 800
 801         return 0;
 802 }
 803
 804 uint16_t
 805 rte_vhost_dequeue_burst(struct virtio_net *dev, uint16_t queue_id,
 806         struct rte_mempool *mbuf_pool, struct rte_mbuf **pkts, uint16_t count)
 807 {
 808         struct rte_mbuf *m, *prev, *rarp_mbuf = NULL;
 809         struct vhost_virtqueue *vq;
 810         struct vring_desc *desc;
 811         uint64_t vb_addr = 0;
 812         uint64_t vb_net_hdr_addr = 0;
 813         uint32_t head[MAX_PKT_BURST];
 814         uint32_t used_idx;
 815         uint32_t i;
 816         uint16_t free_entries, entry_success = 0;
 817         uint16_t avail_idx;
 818         struct virtio_net_hdr *hdr = NULL;
 819
 820         if (unlikely(!is_valid_virt_queue_idx(queue_id, 1, dev->virt_qp_nb))) {
 821                 RTE_LOG(ERR, VHOST_DATA,
 822                         "%s (%"PRIu64"): virtqueue idx:%d invalid.\n",
 823                         __func__, dev->device_fh, queue_id);
 824                 return 0;
 825         }
 826
 827         vq = dev->virtqueue[queue_id];
 828         if (unlikely(vq->enabled == 0))
 829                 return 0;
 830
 831         /*
 832          * Construct a RARP broadcast packet, and inject it to the "pkts"
 833          * array, to looks like that guest actually send such packet.
 834          *
 835          * Check user_send_rarp() for more information.
 836          */
 837         if (unlikely(rte_atomic16_cmpset((volatile uint16_t *)
 838                                          &dev->broadcast_rarp.cnt, 1, 0))) {
 839                 rarp_mbuf = rte_pktmbuf_alloc(mbuf_pool);
 840                 if (rarp_mbuf == NULL) {
 841                         RTE_LOG(ERR, VHOST_DATA,
 842                                 "Failed to allocate memory for mbuf.\n");
 843                         return 0;
 844                 }
 845
 846                 if (make_rarp_packet(rarp_mbuf, &dev->mac)) {
 847                         rte_pktmbuf_free(rarp_mbuf);
 848                         rarp_mbuf = NULL;
 849                 } else {
 850                         count -= 1;
 851                 }
 852         }
 853
 854         avail_idx =  *((volatile uint16_t *)&vq->avail->idx);
 855
 856         /* If there are no available buffers then return. */
 857         if (vq->last_used_idx == avail_idx)
 858                 goto out;
 859
 860         LOG_DEBUG(VHOST_DATA, "%s (%"PRIu64")\n", __func__,
 861                 dev->device_fh);
 862
 863         /* Prefetch available ring to retrieve head indexes. */
 864         rte_prefetch0(&vq->avail->ring[vq->last_used_idx & (vq->size - 1)]);
 865
 866         /*get the number of free entries in the ring*/
 867         free_entries = (avail_idx - vq->last_used_idx);
 868
 869         free_entries = RTE_MIN(free_entries, count);
 870         /* Limit to MAX_PKT_BURST. */
 871         free_entries = RTE_MIN(free_entries, MAX_PKT_BURST);
 872
 873         LOG_DEBUG(VHOST_DATA, "(%"PRIu64") Buffers available %d\n",
 874                         dev->device_fh, free_entries);
 875         /* Retrieve all of the head indexes first to avoid caching issues. */
 876         for (i = 0; i < free_entries; i++)
 877                 head[i] = vq->avail->ring[(vq->last_used_idx + i) & (vq->size - 1)];
 878
 879         /* Prefetch descriptor index. */
 880         rte_prefetch0(&vq->desc[head[entry_success]]);
 881         rte_prefetch0(&vq->used->ring[vq->last_used_idx & (vq->size - 1)]);
 882
 883         while (entry_success < free_entries) {
 884                 uint32_t vb_avail, vb_offset;
 885                 uint32_t seg_avail, seg_offset;
 886                 uint32_t cpy_len;
 887                 uint32_t seg_num = 0;
 888                 struct rte_mbuf *cur;
 889                 uint8_t alloc_err = 0;
 890
 891                 desc = &vq->desc[head[entry_success]];
 892
 893                 vb_net_hdr_addr = gpa_to_vva(dev, desc->addr);
 894                 hdr = (struct virtio_net_hdr *)((uintptr_t)vb_net_hdr_addr);
 895
 896                 /* Discard first buffer as it is the virtio header */
 897                 if (desc->flags & VRING_DESC_F_NEXT) {
 898                         desc = &vq->desc[desc->next];
 899                         vb_offset = 0;
 900                         vb_avail = desc->len;
 901                 } else {
 902                         vb_offset = vq->vhost_hlen;
 903                         vb_avail = desc->len - vb_offset;
 904                 }
 905
 906                 /* Buffer address translation. */
 907                 vb_addr = gpa_to_vva(dev, desc->addr);
 908                 /* Prefetch buffer address. */
 909                 rte_prefetch0((void *)(uintptr_t)vb_addr);
 910
 911                 used_idx = vq->last_used_idx & (vq->size - 1);
 912
 913                 if (entry_success < (free_entries - 1)) {
 914                         /* Prefetch descriptor index. */
 915                         rte_prefetch0(&vq->desc[head[entry_success+1]]);
 916                         rte_prefetch0(&vq->used->ring[(used_idx + 1) & (vq->size - 1)]);
 917                 }
 918
 919                 /* Update used index buffer information. */
 920                 vq->used->ring[used_idx].id = head[entry_success];
 921                 vq->used->ring[used_idx].len = 0;
 922                 vhost_log_used_vring(dev, vq,
 923                                 offsetof(struct vring_used, ring[used_idx]),
 924                                 sizeof(vq->used->ring[used_idx]));
 925
 926                 /* Allocate an mbuf and populate the structure. */
 927                 m = rte_pktmbuf_alloc(mbuf_pool);
 928                 if (unlikely(m == NULL)) {
 929                         RTE_LOG(ERR, VHOST_DATA,
 930                                 "Failed to allocate memory for mbuf.\n");
 931                         break;
 932                 }
 933                 seg_offset = 0;
 934                 seg_avail = m->buf_len - RTE_PKTMBUF_HEADROOM;
 935                 cpy_len = RTE_MIN(vb_avail, seg_avail);
 936
 937                 PRINT_PACKET(dev, (uintptr_t)vb_addr, desc->len, 0);
 938
 939                 seg_num++;
 940                 cur = m;
 941                 prev = m;
 942                 while (cpy_len != 0) {
 943                         rte_memcpy(rte_pktmbuf_mtod_offset(cur, void *, seg_offset),
 944                                 (void *)((uintptr_t)(vb_addr + vb_offset)),
 945                                 cpy_len);
 946
 947                         seg_offset += cpy_len;
 948                         vb_offset += cpy_len;
 949                         vb_avail -= cpy_len;
 950                         seg_avail -= cpy_len;
 951
 952                         if (vb_avail != 0) {
 953                                 /*
 954                                  * The segment reachs to its end,
 955                                  * while the virtio buffer in TX vring has
 956                                  * more data to be copied.
 957                                  */
 958                                 cur->data_len = seg_offset;
 959                                 m->pkt_len += seg_offset;
 960                                 /* Allocate mbuf and populate the structure. */
 961                                 cur = rte_pktmbuf_alloc(mbuf_pool);
 962                                 if (unlikely(cur == NULL)) {
 963                                         RTE_LOG(ERR, VHOST_DATA, "Failed to "
 964                                                 "allocate memory for mbuf.\n");
 965                                         rte_pktmbuf_free(m);
 966                                         alloc_err = 1;
 967                                         break;
 968                                 }
 969
 970                                 seg_num++;
 971                                 prev->next = cur;
 972                                 prev = cur;
 973                                 seg_offset = 0;
 974                                 seg_avail = cur->buf_len - RTE_PKTMBUF_HEADROOM;
 975                         } else {
 976                                 if (desc->flags & VRING_DESC_F_NEXT) {
 977                                         /*
 978                                          * There are more virtio buffers in
 979                                          * same vring entry need to be copied.
 980                                          */
 981                                         if (seg_avail == 0) {
 982                                                 /*
 983                                                  * The current segment hasn't
 984                                                  * room to accomodate more
 985                                                  * data.
 986                                                  */
 987                                                 cur->data_len = seg_offset;
 988                                                 m->pkt_len += seg_offset;
 989                                                 /*
 990                                                  * Allocate an mbuf and
 991                                                  * populate the structure.
 992                                                  */
 993                                                 cur = rte_pktmbuf_alloc(mbuf_pool);
 994                                                 if (unlikely(cur == NULL)) {
 995                                                         RTE_LOG(ERR,
 996                                                                 VHOST_DATA,
 997                                                                 "Failed to "
 998                                                                 "allocate memory "
 999                                                                 "for mbuf\n");
1000                                                         rte_pktmbuf_free(m);
1001                                                         alloc_err = 1;
1002                                                         break;
1003                                                 }
1004                                                 seg_num++;
1005                                                 prev->next = cur;
1006                                                 prev = cur;
1007                                                 seg_offset = 0;
1008                                                 seg_avail = cur->buf_len - RTE_PKTMBUF_HEADROOM;
1009                                         }
1010
1011                                         desc = &vq->desc[desc->next];
1012
1013                                         /* Buffer address translation. */
1014                                         vb_addr = gpa_to_vva(dev, desc->addr);
1015                                         /* Prefetch buffer address. */
1016                                         rte_prefetch0((void *)(uintptr_t)vb_addr);
1017                                         vb_offset = 0;
1018                                         vb_avail = desc->len;
1019
1020                                         PRINT_PACKET(dev, (uintptr_t)vb_addr,
1021                                                 desc->len, 0);
1022                                 } else {
1023                                         /* The whole packet completes. */
1024                                         cur->data_len = seg_offset;
1025                                         m->pkt_len += seg_offset;
1026                                         vb_avail = 0;
1027                                 }
1028                         }
1029
1030                         cpy_len = RTE_MIN(vb_avail, seg_avail);
1031                 }
1032
1033                 if (unlikely(alloc_err == 1))
1034                         break;
1035
1036                 m->nb_segs = seg_num;
1037                 if ((hdr->flags != 0) || (hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE))
1038                         vhost_dequeue_offload(hdr, m);
1039
1040                 pkts[entry_success] = m;
1041                 vq->last_used_idx++;
1042                 entry_success++;
1043         }
1044
1045         rte_compiler_barrier();
1046         vq->used->idx += entry_success;
1047         vhost_log_used_vring(dev, vq, offsetof(struct vring_used, idx),
1048                         sizeof(vq->used->idx));
1049
1050         /* Kick guest if required. */
1051         if (!(vq->avail->flags & VRING_AVAIL_F_NO_INTERRUPT))
1052                 eventfd_write(vq->callfd, (eventfd_t)1);
1053
1054 out:
1055         if (unlikely(rarp_mbuf != NULL)) {
1056                 /*
1057                  * Inject it to the head of "pkts" array, so that switch's mac
1058                  * learning table will get updated first.
1059                  */
1060                 memmove(&pkts[1], pkts, entry_success * sizeof(m));
1061                 pkts[0] = rarp_mbuf;
1062                 entry_success += 1;
1063         }
1064
1065         return entry_success;
1066 }