drivers/net/virtio/virtio_rxtx.c

   1 /* SPDX-License-Identifier: BSD-3-Clause
   2  * Copyright(c) 2010-2014 Intel Corporation
   3  */
   4
   5 #include <stdint.h>
   6 #include <stdio.h>
   7 #include <stdlib.h>
   8 #include <string.h>
   9 #include <errno.h>
  10
  11 #include <rte_cycles.h>
  12 #include <rte_memory.h>
  13 #include <rte_branch_prediction.h>
  14 #include <rte_mempool.h>
  15 #include <rte_malloc.h>
  16 #include <rte_mbuf.h>
  17 #include <rte_ether.h>
  18 #include <rte_ethdev.h>
  19 #include <rte_prefetch.h>
  20 #include <rte_string_fns.h>
  21 #include <rte_errno.h>
  22 #include <rte_byteorder.h>
  23 #include <rte_net.h>
  24 #include <rte_ip.h>
  25 #include <rte_udp.h>
  26 #include <rte_tcp.h>
  27
  28 #include "virtio_logs.h"
  29 #include "virtio_ethdev.h"
  30 #include "virtio_pci.h"
  31 #include "virtqueue.h"
  32 #include "virtio_rxtx.h"
  33
  34 #ifdef RTE_LIBRTE_VIRTIO_DEBUG_DUMP
  35 #define VIRTIO_DUMP_PACKET(m, len) rte_pktmbuf_dump(stdout, m, len)
  36 #else
  37 #define  VIRTIO_DUMP_PACKET(m, len) do { } while (0)
  38 #endif
  39
  40
  41 #define VIRTIO_SIMPLE_FLAGS ((uint32_t)ETH_TXQ_FLAGS_NOMULTSEGS | \
  42         ETH_TXQ_FLAGS_NOOFFLOADS)
  43
  44 int
  45 virtio_dev_rx_queue_done(void *rxq, uint16_t offset)
  46 {
  47         struct virtnet_rx *rxvq = rxq;
  48         struct virtqueue *vq = rxvq->vq;
  49
  50         return VIRTQUEUE_NUSED(vq) >= offset;
  51 }
  52
  53 void
  54 vq_ring_free_chain(struct virtqueue *vq, uint16_t desc_idx)
  55 {
  56         struct vring_desc *dp, *dp_tail;
  57         struct vq_desc_extra *dxp;
  58         uint16_t desc_idx_last = desc_idx;
  59
  60         dp  = &vq->vq_ring.desc[desc_idx];
  61         dxp = &vq->vq_descx[desc_idx];
  62         vq->vq_free_cnt = (uint16_t)(vq->vq_free_cnt + dxp->ndescs);
  63         if ((dp->flags & VRING_DESC_F_INDIRECT) == 0) {
  64                 while (dp->flags & VRING_DESC_F_NEXT) {
  65                         desc_idx_last = dp->next;
  66                         dp = &vq->vq_ring.desc[dp->next];
  67                 }
  68         }
  69         dxp->ndescs = 0;
  70
  71         /*
  72          * We must append the existing free chain, if any, to the end of
  73          * newly freed chain. If the virtqueue was completely used, then
  74          * head would be VQ_RING_DESC_CHAIN_END (ASSERTed above).
  75          */
  76         if (vq->vq_desc_tail_idx == VQ_RING_DESC_CHAIN_END) {
  77                 vq->vq_desc_head_idx = desc_idx;
  78         } else {
  79                 dp_tail = &vq->vq_ring.desc[vq->vq_desc_tail_idx];
  80                 dp_tail->next = desc_idx;
  81         }
  82
  83         vq->vq_desc_tail_idx = desc_idx_last;
  84         dp->next = VQ_RING_DESC_CHAIN_END;
  85 }
  86
  87 static uint16_t
  88 virtqueue_dequeue_burst_rx(struct virtqueue *vq, struct rte_mbuf **rx_pkts,
  89                            uint32_t *len, uint16_t num)
  90 {
  91         struct vring_used_elem *uep;
  92         struct rte_mbuf *cookie;
  93         uint16_t used_idx, desc_idx;
  94         uint16_t i;
  95
  96         /*  Caller does the check */
  97         for (i = 0; i < num ; i++) {
  98                 used_idx = (uint16_t)(vq->vq_used_cons_idx & (vq->vq_nentries - 1));
  99                 uep = &vq->vq_ring.used->ring[used_idx];
 100                 desc_idx = (uint16_t) uep->id;
 101                 len[i] = uep->len;
 102                 cookie = (struct rte_mbuf *)vq->vq_descx[desc_idx].cookie;
 103
 104                 if (unlikely(cookie == NULL)) {
 105                         PMD_DRV_LOG(ERR, "vring descriptor with no mbuf cookie at %u",
 106                                 vq->vq_used_cons_idx);
 107                         break;
 108                 }
 109
 110                 rte_prefetch0(cookie);
 111                 rte_packet_prefetch(rte_pktmbuf_mtod(cookie, void *));
 112                 rx_pkts[i]  = cookie;
 113                 vq->vq_used_cons_idx++;
 114                 vq_ring_free_chain(vq, desc_idx);
 115                 vq->vq_descx[desc_idx].cookie = NULL;
 116         }
 117
 118         return i;
 119 }
 120
 121 #ifndef DEFAULT_TX_FREE_THRESH
 122 #define DEFAULT_TX_FREE_THRESH 32
 123 #endif
 124
 125 /* Cleanup from completed transmits. */
 126 static void
 127 virtio_xmit_cleanup(struct virtqueue *vq, uint16_t num)
 128 {
 129         uint16_t i, used_idx, desc_idx;
 130         for (i = 0; i < num; i++) {
 131                 struct vring_used_elem *uep;
 132                 struct vq_desc_extra *dxp;
 133
 134                 used_idx = (uint16_t)(vq->vq_used_cons_idx & (vq->vq_nentries - 1));
 135                 uep = &vq->vq_ring.used->ring[used_idx];
 136
 137                 desc_idx = (uint16_t) uep->id;
 138                 dxp = &vq->vq_descx[desc_idx];
 139                 vq->vq_used_cons_idx++;
 140                 vq_ring_free_chain(vq, desc_idx);
 141
 142                 if (dxp->cookie != NULL) {
 143                         rte_pktmbuf_free(dxp->cookie);
 144                         dxp->cookie = NULL;
 145                 }
 146         }
 147 }
 148
 149
 150 static inline int
 151 virtqueue_enqueue_recv_refill(struct virtqueue *vq, struct rte_mbuf *cookie)
 152 {
 153         struct vq_desc_extra *dxp;
 154         struct virtio_hw *hw = vq->hw;
 155         struct vring_desc *start_dp;
 156         uint16_t needed = 1;
 157         uint16_t head_idx, idx;
 158
 159         if (unlikely(vq->vq_free_cnt == 0))
 160                 return -ENOSPC;
 161         if (unlikely(vq->vq_free_cnt < needed))
 162                 return -EMSGSIZE;
 163
 164         head_idx = vq->vq_desc_head_idx;
 165         if (unlikely(head_idx >= vq->vq_nentries))
 166                 return -EFAULT;
 167
 168         idx = head_idx;
 169         dxp = &vq->vq_descx[idx];
 170         dxp->cookie = (void *)cookie;
 171         dxp->ndescs = needed;
 172
 173         start_dp = vq->vq_ring.desc;
 174         start_dp[idx].addr =
 175                 VIRTIO_MBUF_ADDR(cookie, vq) +
 176                 RTE_PKTMBUF_HEADROOM - hw->vtnet_hdr_size;
 177         start_dp[idx].len =
 178                 cookie->buf_len - RTE_PKTMBUF_HEADROOM + hw->vtnet_hdr_size;
 179         start_dp[idx].flags =  VRING_DESC_F_WRITE;
 180         idx = start_dp[idx].next;
 181         vq->vq_desc_head_idx = idx;
 182         if (vq->vq_desc_head_idx == VQ_RING_DESC_CHAIN_END)
 183                 vq->vq_desc_tail_idx = idx;
 184         vq->vq_free_cnt = (uint16_t)(vq->vq_free_cnt - needed);
 185         vq_update_avail_ring(vq, head_idx);
 186
 187         return 0;
 188 }
 189
 190 /* When doing TSO, the IP length is not included in the pseudo header
 191  * checksum of the packet given to the PMD, but for virtio it is
 192  * expected.
 193  */
 194 static void
 195 virtio_tso_fix_cksum(struct rte_mbuf *m)
 196 {
 197         /* common case: header is not fragmented */
 198         if (likely(rte_pktmbuf_data_len(m) >= m->l2_len + m->l3_len +
 199                         m->l4_len)) {
 200                 struct ipv4_hdr *iph;
 201                 struct ipv6_hdr *ip6h;
 202                 struct tcp_hdr *th;
 203                 uint16_t prev_cksum, new_cksum, ip_len, ip_paylen;
 204                 uint32_t tmp;
 205
 206                 iph = rte_pktmbuf_mtod_offset(m, struct ipv4_hdr *, m->l2_len);
 207                 th = RTE_PTR_ADD(iph, m->l3_len);
 208                 if ((iph->version_ihl >> 4) == 4) {
 209                         iph->hdr_checksum = 0;
 210                         iph->hdr_checksum = rte_ipv4_cksum(iph);
 211                         ip_len = iph->total_length;
 212                         ip_paylen = rte_cpu_to_be_16(rte_be_to_cpu_16(ip_len) -
 213                                 m->l3_len);
 214                 } else {
 215                         ip6h = (struct ipv6_hdr *)iph;
 216                         ip_paylen = ip6h->payload_len;
 217                 }
 218
 219                 /* calculate the new phdr checksum not including ip_paylen */
 220                 prev_cksum = th->cksum;
 221                 tmp = prev_cksum;
 222                 tmp += ip_paylen;
 223                 tmp = (tmp & 0xffff) + (tmp >> 16);
 224                 new_cksum = tmp;
 225
 226                 /* replace it in the packet */
 227                 th->cksum = new_cksum;
 228         }
 229 }
 230
 231 static inline int
 232 tx_offload_enabled(struct virtio_hw *hw)
 233 {
 234         return vtpci_with_feature(hw, VIRTIO_NET_F_CSUM) ||
 235                 vtpci_with_feature(hw, VIRTIO_NET_F_HOST_TSO4) ||
 236                 vtpci_with_feature(hw, VIRTIO_NET_F_HOST_TSO6);
 237 }
 238
 239 /* avoid write operation when necessary, to lessen cache issues */
 240 #define ASSIGN_UNLESS_EQUAL(var, val) do {      \
 241         if ((var) != (val))                     \
 242                 (var) = (val);                  \
 243 } while (0)
 244
 245 static inline void
 246 virtqueue_enqueue_xmit(struct virtnet_tx *txvq, struct rte_mbuf *cookie,
 247                        uint16_t needed, int use_indirect, int can_push)
 248 {
 249         struct virtio_tx_region *txr = txvq->virtio_net_hdr_mz->addr;
 250         struct vq_desc_extra *dxp;
 251         struct virtqueue *vq = txvq->vq;
 252         struct vring_desc *start_dp;
 253         uint16_t seg_num = cookie->nb_segs;
 254         uint16_t head_idx, idx;
 255         uint16_t head_size = vq->hw->vtnet_hdr_size;
 256         struct virtio_net_hdr *hdr;
 257         int offload;
 258
 259         offload = tx_offload_enabled(vq->hw);
 260         head_idx = vq->vq_desc_head_idx;
 261         idx = head_idx;
 262         dxp = &vq->vq_descx[idx];
 263         dxp->cookie = (void *)cookie;
 264         dxp->ndescs = needed;
 265
 266         start_dp = vq->vq_ring.desc;
 267
 268         if (can_push) {
 269                 /* prepend cannot fail, checked by caller */
 270                 hdr = (struct virtio_net_hdr *)
 271                         rte_pktmbuf_prepend(cookie, head_size);
 272                 /* rte_pktmbuf_prepend() counts the hdr size to the pkt length,
 273                  * which is wrong. Below subtract restores correct pkt size.
 274                  */
 275                 cookie->pkt_len -= head_size;
 276                 /* if offload disabled, it is not zeroed below, do it now */
 277                 if (offload == 0) {
 278                         ASSIGN_UNLESS_EQUAL(hdr->csum_start, 0);
 279                         ASSIGN_UNLESS_EQUAL(hdr->csum_offset, 0);
 280                         ASSIGN_UNLESS_EQUAL(hdr->flags, 0);
 281                         ASSIGN_UNLESS_EQUAL(hdr->gso_type, 0);
 282                         ASSIGN_UNLESS_EQUAL(hdr->gso_size, 0);
 283                         ASSIGN_UNLESS_EQUAL(hdr->hdr_len, 0);
 284                 }
 285         } else if (use_indirect) {
 286                 /* setup tx ring slot to point to indirect
 287                  * descriptor list stored in reserved region.
 288                  *
 289                  * the first slot in indirect ring is already preset
 290                  * to point to the header in reserved region
 291                  */
 292                 start_dp[idx].addr  = txvq->virtio_net_hdr_mem +
 293                         RTE_PTR_DIFF(&txr[idx].tx_indir, txr);
 294                 start_dp[idx].len   = (seg_num + 1) * sizeof(struct vring_desc);
 295                 start_dp[idx].flags = VRING_DESC_F_INDIRECT;
 296                 hdr = (struct virtio_net_hdr *)&txr[idx].tx_hdr;
 297
 298                 /* loop below will fill in rest of the indirect elements */
 299                 start_dp = txr[idx].tx_indir;
 300                 idx = 1;
 301         } else {
 302                 /* setup first tx ring slot to point to header
 303                  * stored in reserved region.
 304                  */
 305                 start_dp[idx].addr  = txvq->virtio_net_hdr_mem +
 306                         RTE_PTR_DIFF(&txr[idx].tx_hdr, txr);
 307                 start_dp[idx].len   = vq->hw->vtnet_hdr_size;
 308                 start_dp[idx].flags = VRING_DESC_F_NEXT;
 309                 hdr = (struct virtio_net_hdr *)&txr[idx].tx_hdr;
 310
 311                 idx = start_dp[idx].next;
 312         }
 313
 314         /* Checksum Offload / TSO */
 315         if (offload) {
 316                 if (cookie->ol_flags & PKT_TX_TCP_SEG)
 317                         cookie->ol_flags |= PKT_TX_TCP_CKSUM;
 318
 319                 switch (cookie->ol_flags & PKT_TX_L4_MASK) {
 320                 case PKT_TX_UDP_CKSUM:
 321                         hdr->csum_start = cookie->l2_len + cookie->l3_len;
 322                         hdr->csum_offset = offsetof(struct udp_hdr,
 323                                 dgram_cksum);
 324                         hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
 325                         break;
 326
 327                 case PKT_TX_TCP_CKSUM:
 328                         hdr->csum_start = cookie->l2_len + cookie->l3_len;
 329                         hdr->csum_offset = offsetof(struct tcp_hdr, cksum);
 330                         hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
 331                         break;
 332
 333                 default:
 334                         ASSIGN_UNLESS_EQUAL(hdr->csum_start, 0);
 335                         ASSIGN_UNLESS_EQUAL(hdr->csum_offset, 0);
 336                         ASSIGN_UNLESS_EQUAL(hdr->flags, 0);
 337                         break;
 338                 }
 339
 340                 /* TCP Segmentation Offload */
 341                 if (cookie->ol_flags & PKT_TX_TCP_SEG) {
 342                         virtio_tso_fix_cksum(cookie);
 343                         hdr->gso_type = (cookie->ol_flags & PKT_TX_IPV6) ?
 344                                 VIRTIO_NET_HDR_GSO_TCPV6 :
 345                                 VIRTIO_NET_HDR_GSO_TCPV4;
 346                         hdr->gso_size = cookie->tso_segsz;
 347                         hdr->hdr_len =
 348                                 cookie->l2_len +
 349                                 cookie->l3_len +
 350                                 cookie->l4_len;
 351                 } else {
 352                         ASSIGN_UNLESS_EQUAL(hdr->gso_type, 0);
 353                         ASSIGN_UNLESS_EQUAL(hdr->gso_size, 0);
 354                         ASSIGN_UNLESS_EQUAL(hdr->hdr_len, 0);
 355                 }
 356         }
 357
 358         do {
 359                 start_dp[idx].addr  = VIRTIO_MBUF_DATA_DMA_ADDR(cookie, vq);
 360                 start_dp[idx].len   = cookie->data_len;
 361                 start_dp[idx].flags = cookie->next ? VRING_DESC_F_NEXT : 0;
 362                 idx = start_dp[idx].next;
 363         } while ((cookie = cookie->next) != NULL);
 364
 365         if (use_indirect)
 366                 idx = vq->vq_ring.desc[head_idx].next;
 367
 368         vq->vq_desc_head_idx = idx;
 369         if (vq->vq_desc_head_idx == VQ_RING_DESC_CHAIN_END)
 370                 vq->vq_desc_tail_idx = idx;
 371         vq->vq_free_cnt = (uint16_t)(vq->vq_free_cnt - needed);
 372         vq_update_avail_ring(vq, head_idx);
 373 }
 374
 375 void
 376 virtio_dev_cq_start(struct rte_eth_dev *dev)
 377 {
 378         struct virtio_hw *hw = dev->data->dev_private;
 379
 380         if (hw->cvq && hw->cvq->vq) {
 381                 VIRTQUEUE_DUMP((struct virtqueue *)hw->cvq->vq);
 382         }
 383 }
 384
 385 int
 386 virtio_dev_rx_queue_setup(struct rte_eth_dev *dev,
 387                         uint16_t queue_idx,
 388                         uint16_t nb_desc,
 389                         unsigned int socket_id __rte_unused,
 390                         __rte_unused const struct rte_eth_rxconf *rx_conf,
 391                         struct rte_mempool *mp)
 392 {
 393         uint16_t vtpci_queue_idx = 2 * queue_idx + VTNET_SQ_RQ_QUEUE_IDX;
 394         struct virtio_hw *hw = dev->data->dev_private;
 395         struct virtqueue *vq = hw->vqs[vtpci_queue_idx];
 396         struct virtnet_rx *rxvq;
 397
 398         PMD_INIT_FUNC_TRACE();
 399
 400         if (nb_desc == 0 || nb_desc > vq->vq_nentries)
 401                 nb_desc = vq->vq_nentries;
 402         vq->vq_free_cnt = RTE_MIN(vq->vq_free_cnt, nb_desc);
 403
 404         rxvq = &vq->rxq;
 405         rxvq->queue_id = queue_idx;
 406         rxvq->mpool = mp;
 407         if (rxvq->mpool == NULL) {
 408                 rte_exit(EXIT_FAILURE,
 409                         "Cannot allocate mbufs for rx virtqueue");
 410         }
 411         dev->data->rx_queues[queue_idx] = rxvq;
 412
 413         return 0;
 414 }
 415
 416 int
 417 virtio_dev_rx_queue_setup_finish(struct rte_eth_dev *dev, uint16_t queue_idx)
 418 {
 419         uint16_t vtpci_queue_idx = 2 * queue_idx + VTNET_SQ_RQ_QUEUE_IDX;
 420         struct virtio_hw *hw = dev->data->dev_private;
 421         struct virtqueue *vq = hw->vqs[vtpci_queue_idx];
 422         struct virtnet_rx *rxvq = &vq->rxq;
 423         struct rte_mbuf *m;
 424         uint16_t desc_idx;
 425         int error, nbufs;
 426
 427         PMD_INIT_FUNC_TRACE();
 428
 429         /* Allocate blank mbufs for the each rx descriptor */
 430         nbufs = 0;
 431
 432         if (hw->use_simple_rx) {
 433                 for (desc_idx = 0; desc_idx < vq->vq_nentries;
 434                      desc_idx++) {
 435                         vq->vq_ring.avail->ring[desc_idx] = desc_idx;
 436                         vq->vq_ring.desc[desc_idx].flags =
 437                                 VRING_DESC_F_WRITE;
 438                 }
 439         }
 440
 441         memset(&rxvq->fake_mbuf, 0, sizeof(rxvq->fake_mbuf));
 442         for (desc_idx = 0; desc_idx < RTE_PMD_VIRTIO_RX_MAX_BURST;
 443              desc_idx++) {
 444                 vq->sw_ring[vq->vq_nentries + desc_idx] =
 445                         &rxvq->fake_mbuf;
 446         }
 447
 448         while (!virtqueue_full(vq)) {
 449                 m = rte_mbuf_raw_alloc(rxvq->mpool);
 450                 if (m == NULL)
 451                         break;
 452
 453                 /* Enqueue allocated buffers */
 454                 if (hw->use_simple_rx)
 455                         error = virtqueue_enqueue_recv_refill_simple(vq, m);
 456                 else
 457                         error = virtqueue_enqueue_recv_refill(vq, m);
 458
 459                 if (error) {
 460                         rte_pktmbuf_free(m);
 461                         break;
 462                 }
 463                 nbufs++;
 464         }
 465
 466         vq_update_avail_idx(vq);
 467
 468         PMD_INIT_LOG(DEBUG, "Allocated %d bufs", nbufs);
 469
 470         virtio_rxq_vec_setup(rxvq);
 471
 472         VIRTQUEUE_DUMP(vq);
 473
 474         return 0;
 475 }
 476
 477 /*
 478  * struct rte_eth_dev *dev: Used to update dev
 479  * uint16_t nb_desc: Defaults to values read from config space
 480  * unsigned int socket_id: Used to allocate memzone
 481  * const struct rte_eth_txconf *tx_conf: Used to setup tx engine
 482  * uint16_t queue_idx: Just used as an index in dev txq list
 483  */
 484 int
 485 virtio_dev_tx_queue_setup(struct rte_eth_dev *dev,
 486                         uint16_t queue_idx,
 487                         uint16_t nb_desc,
 488                         unsigned int socket_id __rte_unused,
 489                         const struct rte_eth_txconf *tx_conf)
 490 {
 491         uint8_t vtpci_queue_idx = 2 * queue_idx + VTNET_SQ_TQ_QUEUE_IDX;
 492         struct virtio_hw *hw = dev->data->dev_private;
 493         struct virtqueue *vq = hw->vqs[vtpci_queue_idx];
 494         struct virtnet_tx *txvq;
 495         uint16_t tx_free_thresh;
 496
 497         PMD_INIT_FUNC_TRACE();
 498
 499         /* cannot use simple rxtx funcs with multisegs or offloads */
 500         if ((tx_conf->txq_flags & VIRTIO_SIMPLE_FLAGS) != VIRTIO_SIMPLE_FLAGS)
 501                 hw->use_simple_tx = 0;
 502
 503         if (nb_desc == 0 || nb_desc > vq->vq_nentries)
 504                 nb_desc = vq->vq_nentries;
 505         vq->vq_free_cnt = RTE_MIN(vq->vq_free_cnt, nb_desc);
 506
 507         txvq = &vq->txq;
 508         txvq->queue_id = queue_idx;
 509
 510         tx_free_thresh = tx_conf->tx_free_thresh;
 511         if (tx_free_thresh == 0)
 512                 tx_free_thresh =
 513                         RTE_MIN(vq->vq_nentries / 4, DEFAULT_TX_FREE_THRESH);
 514
 515         if (tx_free_thresh >= (vq->vq_nentries - 3)) {
 516                 RTE_LOG(ERR, PMD, "tx_free_thresh must be less than the "
 517                         "number of TX entries minus 3 (%u)."
 518                         " (tx_free_thresh=%u port=%u queue=%u)\n",
 519                         vq->vq_nentries - 3,
 520                         tx_free_thresh, dev->data->port_id, queue_idx);
 521                 return -EINVAL;
 522         }
 523
 524         vq->vq_free_thresh = tx_free_thresh;
 525
 526         dev->data->tx_queues[queue_idx] = txvq;
 527         return 0;
 528 }
 529
 530 int
 531 virtio_dev_tx_queue_setup_finish(struct rte_eth_dev *dev,
 532                                 uint16_t queue_idx)
 533 {
 534         uint8_t vtpci_queue_idx = 2 * queue_idx + VTNET_SQ_TQ_QUEUE_IDX;
 535         struct virtio_hw *hw = dev->data->dev_private;
 536         struct virtqueue *vq = hw->vqs[vtpci_queue_idx];
 537         uint16_t mid_idx = vq->vq_nentries >> 1;
 538         struct virtnet_tx *txvq = &vq->txq;
 539         uint16_t desc_idx;
 540
 541         PMD_INIT_FUNC_TRACE();
 542
 543         if (hw->use_simple_tx) {
 544                 for (desc_idx = 0; desc_idx < mid_idx; desc_idx++) {
 545                         vq->vq_ring.avail->ring[desc_idx] =
 546                                 desc_idx + mid_idx;
 547                         vq->vq_ring.desc[desc_idx + mid_idx].next =
 548                                 desc_idx;
 549                         vq->vq_ring.desc[desc_idx + mid_idx].addr =
 550                                 txvq->virtio_net_hdr_mem +
 551                                 offsetof(struct virtio_tx_region, tx_hdr);
 552                         vq->vq_ring.desc[desc_idx + mid_idx].len =
 553                                 vq->hw->vtnet_hdr_size;
 554                         vq->vq_ring.desc[desc_idx + mid_idx].flags =
 555                                 VRING_DESC_F_NEXT;
 556                         vq->vq_ring.desc[desc_idx].flags = 0;
 557                 }
 558                 for (desc_idx = mid_idx; desc_idx < vq->vq_nentries;
 559                      desc_idx++)
 560                         vq->vq_ring.avail->ring[desc_idx] = desc_idx;
 561         }
 562
 563         VIRTQUEUE_DUMP(vq);
 564
 565         return 0;
 566 }
 567
 568 static void
 569 virtio_discard_rxbuf(struct virtqueue *vq, struct rte_mbuf *m)
 570 {
 571         int error;
 572         /*
 573          * Requeue the discarded mbuf. This should always be
 574          * successful since it was just dequeued.
 575          */
 576         error = virtqueue_enqueue_recv_refill(vq, m);
 577         if (unlikely(error)) {
 578                 RTE_LOG(ERR, PMD, "cannot requeue discarded mbuf");
 579                 rte_pktmbuf_free(m);
 580         }
 581 }
 582
 583 static void
 584 virtio_update_packet_stats(struct virtnet_stats *stats, struct rte_mbuf *mbuf)
 585 {
 586         uint32_t s = mbuf->pkt_len;
 587         struct ether_addr *ea;
 588
 589         if (s == 64) {
 590                 stats->size_bins[1]++;
 591         } else if (s > 64 && s < 1024) {
 592                 uint32_t bin;
 593
 594                 /* count zeros, and offset into correct bin */
 595                 bin = (sizeof(s) * 8) - __builtin_clz(s) - 5;
 596                 stats->size_bins[bin]++;
 597         } else {
 598                 if (s < 64)
 599                         stats->size_bins[0]++;
 600                 else if (s < 1519)
 601                         stats->size_bins[6]++;
 602                 else if (s >= 1519)
 603                         stats->size_bins[7]++;
 604         }
 605
 606         ea = rte_pktmbuf_mtod(mbuf, struct ether_addr *);
 607         if (is_multicast_ether_addr(ea)) {
 608                 if (is_broadcast_ether_addr(ea))
 609                         stats->broadcast++;
 610                 else
 611                         stats->multicast++;
 612         }
 613 }
 614
 615 /* Optionally fill offload information in structure */
 616 static int
 617 virtio_rx_offload(struct rte_mbuf *m, struct virtio_net_hdr *hdr)
 618 {
 619         struct rte_net_hdr_lens hdr_lens;
 620         uint32_t hdrlen, ptype;
 621         int l4_supported = 0;
 622
 623         /* nothing to do */
 624         if (hdr->flags == 0 && hdr->gso_type == VIRTIO_NET_HDR_GSO_NONE)
 625                 return 0;
 626
 627         m->ol_flags |= PKT_RX_IP_CKSUM_UNKNOWN;
 628
 629         ptype = rte_net_get_ptype(m, &hdr_lens, RTE_PTYPE_ALL_MASK);
 630         m->packet_type = ptype;
 631         if ((ptype & RTE_PTYPE_L4_MASK) == RTE_PTYPE_L4_TCP ||
 632             (ptype & RTE_PTYPE_L4_MASK) == RTE_PTYPE_L4_UDP ||
 633             (ptype & RTE_PTYPE_L4_MASK) == RTE_PTYPE_L4_SCTP)
 634                 l4_supported = 1;
 635
 636         if (hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
 637                 hdrlen = hdr_lens.l2_len + hdr_lens.l3_len + hdr_lens.l4_len;
 638                 if (hdr->csum_start <= hdrlen && l4_supported) {
 639                         m->ol_flags |= PKT_RX_L4_CKSUM_NONE;
 640                 } else {
 641                         /* Unknown proto or tunnel, do sw cksum. We can assume
 642                          * the cksum field is in the first segment since the
 643                          * buffers we provided to the host are large enough.
 644                          * In case of SCTP, this will be wrong since it's a CRC
 645                          * but there's nothing we can do.
 646                          */
 647                         uint16_t csum = 0, off;
 648
 649                         rte_raw_cksum_mbuf(m, hdr->csum_start,
 650                                 rte_pktmbuf_pkt_len(m) - hdr->csum_start,
 651                                 &csum);
 652                         if (likely(csum != 0xffff))
 653                                 csum = ~csum;
 654                         off = hdr->csum_offset + hdr->csum_start;
 655                         if (rte_pktmbuf_data_len(m) >= off + 1)
 656                                 *rte_pktmbuf_mtod_offset(m, uint16_t *,
 657                                         off) = csum;
 658                 }
 659         } else if (hdr->flags & VIRTIO_NET_HDR_F_DATA_VALID && l4_supported) {
 660                 m->ol_flags |= PKT_RX_L4_CKSUM_GOOD;
 661         }
 662
 663         /* GSO request, save required information in mbuf */
 664         if (hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) {
 665                 /* Check unsupported modes */
 666                 if ((hdr->gso_type & VIRTIO_NET_HDR_GSO_ECN) ||
 667                     (hdr->gso_size == 0)) {
 668                         return -EINVAL;
 669                 }
 670
 671                 /* Update mss lengthes in mbuf */
 672                 m->tso_segsz = hdr->gso_size;
 673                 switch (hdr->gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
 674                         case VIRTIO_NET_HDR_GSO_TCPV4:
 675                         case VIRTIO_NET_HDR_GSO_TCPV6:
 676                                 m->ol_flags |= PKT_RX_LRO | \
 677                                         PKT_RX_L4_CKSUM_NONE;
 678                                 break;
 679                         default:
 680                                 return -EINVAL;
 681                 }
 682         }
 683
 684         return 0;
 685 }
 686
 687 static inline int
 688 rx_offload_enabled(struct virtio_hw *hw)
 689 {
 690         return vtpci_with_feature(hw, VIRTIO_NET_F_GUEST_CSUM) ||
 691                 vtpci_with_feature(hw, VIRTIO_NET_F_GUEST_TSO4) ||
 692                 vtpci_with_feature(hw, VIRTIO_NET_F_GUEST_TSO6);
 693 }
 694
 695 #define VIRTIO_MBUF_BURST_SZ 64
 696 #define DESC_PER_CACHELINE (RTE_CACHE_LINE_SIZE / sizeof(struct vring_desc))
 697 uint16_t
 698 virtio_recv_pkts(void *rx_queue, struct rte_mbuf **rx_pkts, uint16_t nb_pkts)
 699 {
 700         struct virtnet_rx *rxvq = rx_queue;
 701         struct virtqueue *vq = rxvq->vq;
 702         struct virtio_hw *hw = vq->hw;
 703         struct rte_mbuf *rxm, *new_mbuf;
 704         uint16_t nb_used, num, nb_rx;
 705         uint32_t len[VIRTIO_MBUF_BURST_SZ];
 706         struct rte_mbuf *rcv_pkts[VIRTIO_MBUF_BURST_SZ];
 707         int error;
 708         uint32_t i, nb_enqueued;
 709         uint32_t hdr_size;
 710         int offload;
 711         struct virtio_net_hdr *hdr;
 712
 713         nb_rx = 0;
 714         if (unlikely(hw->started == 0))
 715                 return nb_rx;
 716
 717         nb_used = VIRTQUEUE_NUSED(vq);
 718
 719         virtio_rmb();
 720
 721         num = likely(nb_used <= nb_pkts) ? nb_used : nb_pkts;
 722         if (unlikely(num > VIRTIO_MBUF_BURST_SZ))
 723                 num = VIRTIO_MBUF_BURST_SZ;
 724         if (likely(num > DESC_PER_CACHELINE))
 725                 num = num - ((vq->vq_used_cons_idx + num) % DESC_PER_CACHELINE);
 726
 727         num = virtqueue_dequeue_burst_rx(vq, rcv_pkts, len, num);
 728         PMD_RX_LOG(DEBUG, "used:%d dequeue:%d", nb_used, num);
 729
 730         nb_enqueued = 0;
 731         hdr_size = hw->vtnet_hdr_size;
 732         offload = rx_offload_enabled(hw);
 733
 734         for (i = 0; i < num ; i++) {
 735                 rxm = rcv_pkts[i];
 736
 737                 PMD_RX_LOG(DEBUG, "packet len:%d", len[i]);
 738
 739                 if (unlikely(len[i] < hdr_size + ETHER_HDR_LEN)) {
 740                         PMD_RX_LOG(ERR, "Packet drop");
 741                         nb_enqueued++;
 742                         virtio_discard_rxbuf(vq, rxm);
 743                         rxvq->stats.errors++;
 744                         continue;
 745                 }
 746
 747                 rxm->port = rxvq->port_id;
 748                 rxm->data_off = RTE_PKTMBUF_HEADROOM;
 749                 rxm->ol_flags = 0;
 750                 rxm->vlan_tci = 0;
 751
 752                 rxm->pkt_len = (uint32_t)(len[i] - hdr_size);
 753                 rxm->data_len = (uint16_t)(len[i] - hdr_size);
 754
 755                 hdr = (struct virtio_net_hdr *)((char *)rxm->buf_addr +
 756                         RTE_PKTMBUF_HEADROOM - hdr_size);
 757
 758                 if (hw->vlan_strip)
 759                         rte_vlan_strip(rxm);
 760
 761                 if (offload && virtio_rx_offload(rxm, hdr) < 0) {
 762                         virtio_discard_rxbuf(vq, rxm);
 763                         rxvq->stats.errors++;
 764                         continue;
 765                 }
 766
 767                 VIRTIO_DUMP_PACKET(rxm, rxm->data_len);
 768
 769                 rx_pkts[nb_rx++] = rxm;
 770
 771                 rxvq->stats.bytes += rxm->pkt_len;
 772                 virtio_update_packet_stats(&rxvq->stats, rxm);
 773         }
 774
 775         rxvq->stats.packets += nb_rx;
 776
 777         /* Allocate new mbuf for the used descriptor */
 778         error = ENOSPC;
 779         while (likely(!virtqueue_full(vq))) {
 780                 new_mbuf = rte_mbuf_raw_alloc(rxvq->mpool);
 781                 if (unlikely(new_mbuf == NULL)) {
 782                         struct rte_eth_dev *dev
 783                                 = &rte_eth_devices[rxvq->port_id];
 784                         dev->data->rx_mbuf_alloc_failed++;
 785                         break;
 786                 }
 787                 error = virtqueue_enqueue_recv_refill(vq, new_mbuf);
 788                 if (unlikely(error)) {
 789                         rte_pktmbuf_free(new_mbuf);
 790                         break;
 791                 }
 792                 nb_enqueued++;
 793         }
 794
 795         if (likely(nb_enqueued)) {
 796                 vq_update_avail_idx(vq);
 797
 798                 if (unlikely(virtqueue_kick_prepare(vq))) {
 799                         virtqueue_notify(vq);
 800                         PMD_RX_LOG(DEBUG, "Notified");
 801                 }
 802         }
 803
 804         return nb_rx;
 805 }
 806
 807 uint16_t
 808 virtio_recv_mergeable_pkts(void *rx_queue,
 809                         struct rte_mbuf **rx_pkts,
 810                         uint16_t nb_pkts)
 811 {
 812         struct virtnet_rx *rxvq = rx_queue;
 813         struct virtqueue *vq = rxvq->vq;
 814         struct virtio_hw *hw = vq->hw;
 815         struct rte_mbuf *rxm, *new_mbuf;
 816         uint16_t nb_used, num, nb_rx;
 817         uint32_t len[VIRTIO_MBUF_BURST_SZ];
 818         struct rte_mbuf *rcv_pkts[VIRTIO_MBUF_BURST_SZ];
 819         struct rte_mbuf *prev;
 820         int error;
 821         uint32_t i, nb_enqueued;
 822         uint32_t seg_num;
 823         uint16_t extra_idx;
 824         uint32_t seg_res;
 825         uint32_t hdr_size;
 826         int offload;
 827
 828         nb_rx = 0;
 829         if (unlikely(hw->started == 0))
 830                 return nb_rx;
 831
 832         nb_used = VIRTQUEUE_NUSED(vq);
 833
 834         virtio_rmb();
 835
 836         PMD_RX_LOG(DEBUG, "used:%d", nb_used);
 837
 838         i = 0;
 839         nb_enqueued = 0;
 840         seg_num = 0;
 841         extra_idx = 0;
 842         seg_res = 0;
 843         hdr_size = hw->vtnet_hdr_size;
 844         offload = rx_offload_enabled(hw);
 845
 846         while (i < nb_used) {
 847                 struct virtio_net_hdr_mrg_rxbuf *header;
 848
 849                 if (nb_rx == nb_pkts)
 850                         break;
 851
 852                 num = virtqueue_dequeue_burst_rx(vq, rcv_pkts, len, 1);
 853                 if (num != 1)
 854                         continue;
 855
 856                 i++;
 857
 858                 PMD_RX_LOG(DEBUG, "dequeue:%d", num);
 859                 PMD_RX_LOG(DEBUG, "packet len:%d", len[0]);
 860
 861                 rxm = rcv_pkts[0];
 862
 863                 if (unlikely(len[0] < hdr_size + ETHER_HDR_LEN)) {
 864                         PMD_RX_LOG(ERR, "Packet drop");
 865                         nb_enqueued++;
 866                         virtio_discard_rxbuf(vq, rxm);
 867                         rxvq->stats.errors++;
 868                         continue;
 869                 }
 870
 871                 header = (struct virtio_net_hdr_mrg_rxbuf *)((char *)rxm->buf_addr +
 872                         RTE_PKTMBUF_HEADROOM - hdr_size);
 873                 seg_num = header->num_buffers;
 874
 875                 if (seg_num == 0)
 876                         seg_num = 1;
 877
 878                 rxm->data_off = RTE_PKTMBUF_HEADROOM;
 879                 rxm->nb_segs = seg_num;
 880                 rxm->ol_flags = 0;
 881                 rxm->vlan_tci = 0;
 882                 rxm->pkt_len = (uint32_t)(len[0] - hdr_size);
 883                 rxm->data_len = (uint16_t)(len[0] - hdr_size);
 884
 885                 rxm->port = rxvq->port_id;
 886                 rx_pkts[nb_rx] = rxm;
 887                 prev = rxm;
 888
 889                 if (offload && virtio_rx_offload(rxm, &header->hdr) < 0) {
 890                         virtio_discard_rxbuf(vq, rxm);
 891                         rxvq->stats.errors++;
 892                         continue;
 893                 }
 894
 895                 seg_res = seg_num - 1;
 896
 897                 while (seg_res != 0) {
 898                         /*
 899                          * Get extra segments for current uncompleted packet.
 900                          */
 901                         uint16_t  rcv_cnt =
 902                                 RTE_MIN(seg_res, RTE_DIM(rcv_pkts));
 903                         if (likely(VIRTQUEUE_NUSED(vq) >= rcv_cnt)) {
 904                                 uint32_t rx_num =
 905                                         virtqueue_dequeue_burst_rx(vq,
 906                                         rcv_pkts, len, rcv_cnt);
 907                                 i += rx_num;
 908                                 rcv_cnt = rx_num;
 909                         } else {
 910                                 PMD_RX_LOG(ERR,
 911                                            "No enough segments for packet.");
 912                                 nb_enqueued++;
 913                                 virtio_discard_rxbuf(vq, rxm);
 914                                 rxvq->stats.errors++;
 915                                 break;
 916                         }
 917
 918                         extra_idx = 0;
 919
 920                         while (extra_idx < rcv_cnt) {
 921                                 rxm = rcv_pkts[extra_idx];
 922
 923                                 rxm->data_off = RTE_PKTMBUF_HEADROOM - hdr_size;
 924                                 rxm->pkt_len = (uint32_t)(len[extra_idx]);
 925                                 rxm->data_len = (uint16_t)(len[extra_idx]);
 926
 927                                 if (prev)
 928                                         prev->next = rxm;
 929
 930                                 prev = rxm;
 931                                 rx_pkts[nb_rx]->pkt_len += rxm->pkt_len;
 932                                 extra_idx++;
 933                         };
 934                         seg_res -= rcv_cnt;
 935                 }
 936
 937                 if (hw->vlan_strip)
 938                         rte_vlan_strip(rx_pkts[nb_rx]);
 939
 940                 VIRTIO_DUMP_PACKET(rx_pkts[nb_rx],
 941                         rx_pkts[nb_rx]->data_len);
 942
 943                 rxvq->stats.bytes += rx_pkts[nb_rx]->pkt_len;
 944                 virtio_update_packet_stats(&rxvq->stats, rx_pkts[nb_rx]);
 945                 nb_rx++;
 946         }
 947
 948         rxvq->stats.packets += nb_rx;
 949
 950         /* Allocate new mbuf for the used descriptor */
 951         error = ENOSPC;
 952         while (likely(!virtqueue_full(vq))) {
 953                 new_mbuf = rte_mbuf_raw_alloc(rxvq->mpool);
 954                 if (unlikely(new_mbuf == NULL)) {
 955                         struct rte_eth_dev *dev
 956                                 = &rte_eth_devices[rxvq->port_id];
 957                         dev->data->rx_mbuf_alloc_failed++;
 958                         break;
 959                 }
 960                 error = virtqueue_enqueue_recv_refill(vq, new_mbuf);
 961                 if (unlikely(error)) {
 962                         rte_pktmbuf_free(new_mbuf);
 963                         break;
 964                 }
 965                 nb_enqueued++;
 966         }
 967
 968         if (likely(nb_enqueued)) {
 969                 vq_update_avail_idx(vq);
 970
 971                 if (unlikely(virtqueue_kick_prepare(vq))) {
 972                         virtqueue_notify(vq);
 973                         PMD_RX_LOG(DEBUG, "Notified");
 974                 }
 975         }
 976
 977         return nb_rx;
 978 }
 979
 980 uint16_t
 981 virtio_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts, uint16_t nb_pkts)
 982 {
 983         struct virtnet_tx *txvq = tx_queue;
 984         struct virtqueue *vq = txvq->vq;
 985         struct virtio_hw *hw = vq->hw;
 986         uint16_t hdr_size = hw->vtnet_hdr_size;
 987         uint16_t nb_used, nb_tx = 0;
 988         int error;
 989
 990         if (unlikely(hw->started == 0))
 991                 return nb_tx;
 992
 993         if (unlikely(nb_pkts < 1))
 994                 return nb_pkts;
 995
 996         PMD_TX_LOG(DEBUG, "%d packets to xmit", nb_pkts);
 997         nb_used = VIRTQUEUE_NUSED(vq);
 998
 999         virtio_rmb();
1000         if (likely(nb_used > vq->vq_nentries - vq->vq_free_thresh))
1001                 virtio_xmit_cleanup(vq, nb_used);
1002
1003         for (nb_tx = 0; nb_tx < nb_pkts; nb_tx++) {
1004                 struct rte_mbuf *txm = tx_pkts[nb_tx];
1005                 int can_push = 0, use_indirect = 0, slots, need;
1006
1007                 /* Do VLAN tag insertion */
1008                 if (unlikely(txm->ol_flags & PKT_TX_VLAN_PKT)) {
1009                         error = rte_vlan_insert(&txm);
1010                         if (unlikely(error)) {
1011                                 rte_pktmbuf_free(txm);
1012                                 continue;
1013                         }
1014                 }
1015
1016                 /* optimize ring usage */
1017                 if ((vtpci_with_feature(hw, VIRTIO_F_ANY_LAYOUT) ||
1018                       vtpci_with_feature(hw, VIRTIO_F_VERSION_1)) &&
1019                     rte_mbuf_refcnt_read(txm) == 1 &&
1020                     RTE_MBUF_DIRECT(txm) &&
1021                     txm->nb_segs == 1 &&
1022                     rte_pktmbuf_headroom(txm) >= hdr_size &&
1023                     rte_is_aligned(rte_pktmbuf_mtod(txm, char *),
1024                                    __alignof__(struct virtio_net_hdr_mrg_rxbuf)))
1025                         can_push = 1;
1026                 else if (vtpci_with_feature(hw, VIRTIO_RING_F_INDIRECT_DESC) &&
1027                          txm->nb_segs < VIRTIO_MAX_TX_INDIRECT)
1028                         use_indirect = 1;
1029
1030                 /* How many main ring entries are needed to this Tx?
1031                  * any_layout => number of segments
1032                  * indirect   => 1
1033                  * default    => number of segments + 1
1034                  */
1035                 slots = use_indirect ? 1 : (txm->nb_segs + !can_push);
1036                 need = slots - vq->vq_free_cnt;
1037
1038                 /* Positive value indicates it need free vring descriptors */
1039                 if (unlikely(need > 0)) {
1040                         nb_used = VIRTQUEUE_NUSED(vq);
1041                         virtio_rmb();
1042                         need = RTE_MIN(need, (int)nb_used);
1043
1044                         virtio_xmit_cleanup(vq, need);
1045                         need = slots - vq->vq_free_cnt;
1046                         if (unlikely(need > 0)) {
1047                                 PMD_TX_LOG(ERR,
1048                                            "No free tx descriptors to transmit");
1049                                 break;
1050                         }
1051                 }
1052
1053                 /* Enqueue Packet buffers */
1054                 virtqueue_enqueue_xmit(txvq, txm, slots, use_indirect, can_push);
1055
1056                 txvq->stats.bytes += txm->pkt_len;
1057                 virtio_update_packet_stats(&txvq->stats, txm);
1058         }
1059
1060         txvq->stats.packets += nb_tx;
1061
1062         if (likely(nb_tx)) {
1063                 vq_update_avail_idx(vq);
1064
1065                 if (unlikely(virtqueue_kick_prepare(vq))) {
1066                         virtqueue_notify(vq);
1067                         PMD_TX_LOG(DEBUG, "Notified backend after xmit");
1068                 }
1069         }
1070
1071         return nb_tx;
1072 }