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                 rte_spinlock_init(&hw->cvq->lock);
 382                 VIRTQUEUE_DUMP((struct virtqueue *)hw->cvq->vq);
 383         }
 384 }
 385
 386 int
 387 virtio_dev_rx_queue_setup(struct rte_eth_dev *dev,
 388                         uint16_t queue_idx,
 389                         uint16_t nb_desc,
 390                         unsigned int socket_id __rte_unused,
 391                         __rte_unused const struct rte_eth_rxconf *rx_conf,
 392                         struct rte_mempool *mp)
 393 {
 394         uint16_t vtpci_queue_idx = 2 * queue_idx + VTNET_SQ_RQ_QUEUE_IDX;
 395         struct virtio_hw *hw = dev->data->dev_private;
 396         struct virtqueue *vq = hw->vqs[vtpci_queue_idx];
 397         struct virtnet_rx *rxvq;
 398
 399         PMD_INIT_FUNC_TRACE();
 400
 401         if (nb_desc == 0 || nb_desc > vq->vq_nentries)
 402                 nb_desc = vq->vq_nentries;
 403         vq->vq_free_cnt = RTE_MIN(vq->vq_free_cnt, nb_desc);
 404
 405         rxvq = &vq->rxq;
 406         rxvq->queue_id = queue_idx;
 407         rxvq->mpool = mp;
 408         if (rxvq->mpool == NULL) {
 409                 rte_exit(EXIT_FAILURE,
 410                         "Cannot allocate mbufs for rx virtqueue");
 411         }
 412         dev->data->rx_queues[queue_idx] = rxvq;
 413
 414         return 0;
 415 }
 416
 417 int
 418 virtio_dev_rx_queue_setup_finish(struct rte_eth_dev *dev, uint16_t queue_idx)
 419 {
 420         uint16_t vtpci_queue_idx = 2 * queue_idx + VTNET_SQ_RQ_QUEUE_IDX;
 421         struct virtio_hw *hw = dev->data->dev_private;
 422         struct virtqueue *vq = hw->vqs[vtpci_queue_idx];
 423         struct virtnet_rx *rxvq = &vq->rxq;
 424         struct rte_mbuf *m;
 425         uint16_t desc_idx;
 426         int error, nbufs;
 427
 428         PMD_INIT_FUNC_TRACE();
 429
 430         /* Allocate blank mbufs for the each rx descriptor */
 431         nbufs = 0;
 432
 433         if (hw->use_simple_rx) {
 434                 for (desc_idx = 0; desc_idx < vq->vq_nentries;
 435                      desc_idx++) {
 436                         vq->vq_ring.avail->ring[desc_idx] = desc_idx;
 437                         vq->vq_ring.desc[desc_idx].flags =
 438                                 VRING_DESC_F_WRITE;
 439                 }
 440         }
 441
 442         memset(&rxvq->fake_mbuf, 0, sizeof(rxvq->fake_mbuf));
 443         for (desc_idx = 0; desc_idx < RTE_PMD_VIRTIO_RX_MAX_BURST;
 444              desc_idx++) {
 445                 vq->sw_ring[vq->vq_nentries + desc_idx] =
 446                         &rxvq->fake_mbuf;
 447         }
 448
 449         while (!virtqueue_full(vq)) {
 450                 m = rte_mbuf_raw_alloc(rxvq->mpool);
 451                 if (m == NULL)
 452                         break;
 453
 454                 /* Enqueue allocated buffers */
 455                 if (hw->use_simple_rx)
 456                         error = virtqueue_enqueue_recv_refill_simple(vq, m);
 457                 else
 458                         error = virtqueue_enqueue_recv_refill(vq, m);
 459
 460                 if (error) {
 461                         rte_pktmbuf_free(m);
 462                         break;
 463                 }
 464                 nbufs++;
 465         }
 466
 467         vq_update_avail_idx(vq);
 468
 469         PMD_INIT_LOG(DEBUG, "Allocated %d bufs", nbufs);
 470
 471         virtio_rxq_vec_setup(rxvq);
 472
 473         VIRTQUEUE_DUMP(vq);
 474
 475         return 0;
 476 }
 477
 478 /*
 479  * struct rte_eth_dev *dev: Used to update dev
 480  * uint16_t nb_desc: Defaults to values read from config space
 481  * unsigned int socket_id: Used to allocate memzone
 482  * const struct rte_eth_txconf *tx_conf: Used to setup tx engine
 483  * uint16_t queue_idx: Just used as an index in dev txq list
 484  */
 485 int
 486 virtio_dev_tx_queue_setup(struct rte_eth_dev *dev,
 487                         uint16_t queue_idx,
 488                         uint16_t nb_desc,
 489                         unsigned int socket_id __rte_unused,
 490                         const struct rte_eth_txconf *tx_conf)
 491 {
 492         uint8_t vtpci_queue_idx = 2 * queue_idx + VTNET_SQ_TQ_QUEUE_IDX;
 493         struct virtio_hw *hw = dev->data->dev_private;
 494         struct virtqueue *vq = hw->vqs[vtpci_queue_idx];
 495         struct virtnet_tx *txvq;
 496         uint16_t tx_free_thresh;
 497
 498         PMD_INIT_FUNC_TRACE();
 499
 500         /* cannot use simple rxtx funcs with multisegs or offloads */
 501         if ((tx_conf->txq_flags & VIRTIO_SIMPLE_FLAGS) != VIRTIO_SIMPLE_FLAGS)
 502                 hw->use_simple_tx = 0;
 503
 504         if (nb_desc == 0 || nb_desc > vq->vq_nentries)
 505                 nb_desc = vq->vq_nentries;
 506         vq->vq_free_cnt = RTE_MIN(vq->vq_free_cnt, nb_desc);
 507
 508         txvq = &vq->txq;
 509         txvq->queue_id = queue_idx;
 510
 511         tx_free_thresh = tx_conf->tx_free_thresh;
 512         if (tx_free_thresh == 0)
 513                 tx_free_thresh =
 514                         RTE_MIN(vq->vq_nentries / 4, DEFAULT_TX_FREE_THRESH);
 515
 516         if (tx_free_thresh >= (vq->vq_nentries - 3)) {
 517                 RTE_LOG(ERR, PMD, "tx_free_thresh must be less than the "
 518                         "number of TX entries minus 3 (%u)."
 519                         " (tx_free_thresh=%u port=%u queue=%u)\n",
 520                         vq->vq_nentries - 3,
 521                         tx_free_thresh, dev->data->port_id, queue_idx);
 522                 return -EINVAL;
 523         }
 524
 525         vq->vq_free_thresh = tx_free_thresh;
 526
 527         dev->data->tx_queues[queue_idx] = txvq;
 528         return 0;
 529 }
 530
 531 int
 532 virtio_dev_tx_queue_setup_finish(struct rte_eth_dev *dev,
 533                                 uint16_t queue_idx)
 534 {
 535         uint8_t vtpci_queue_idx = 2 * queue_idx + VTNET_SQ_TQ_QUEUE_IDX;
 536         struct virtio_hw *hw = dev->data->dev_private;
 537         struct virtqueue *vq = hw->vqs[vtpci_queue_idx];
 538         uint16_t mid_idx = vq->vq_nentries >> 1;
 539         struct virtnet_tx *txvq = &vq->txq;
 540         uint16_t desc_idx;
 541
 542         PMD_INIT_FUNC_TRACE();
 543
 544         if (hw->use_simple_tx) {
 545                 for (desc_idx = 0; desc_idx < mid_idx; desc_idx++) {
 546                         vq->vq_ring.avail->ring[desc_idx] =
 547                                 desc_idx + mid_idx;
 548                         vq->vq_ring.desc[desc_idx + mid_idx].next =
 549                                 desc_idx;
 550                         vq->vq_ring.desc[desc_idx + mid_idx].addr =
 551                                 txvq->virtio_net_hdr_mem +
 552                                 offsetof(struct virtio_tx_region, tx_hdr);
 553                         vq->vq_ring.desc[desc_idx + mid_idx].len =
 554                                 vq->hw->vtnet_hdr_size;
 555                         vq->vq_ring.desc[desc_idx + mid_idx].flags =
 556                                 VRING_DESC_F_NEXT;
 557                         vq->vq_ring.desc[desc_idx].flags = 0;
 558                 }
 559                 for (desc_idx = mid_idx; desc_idx < vq->vq_nentries;
 560                      desc_idx++)
 561                         vq->vq_ring.avail->ring[desc_idx] = desc_idx;
 562         }
 563
 564         VIRTQUEUE_DUMP(vq);
 565
 566         return 0;
 567 }
 568
 569 static void
 570 virtio_discard_rxbuf(struct virtqueue *vq, struct rte_mbuf *m)
 571 {
 572         int error;
 573         /*
 574          * Requeue the discarded mbuf. This should always be
 575          * successful since it was just dequeued.
 576          */
 577         error = virtqueue_enqueue_recv_refill(vq, m);
 578         if (unlikely(error)) {
 579                 RTE_LOG(ERR, PMD, "cannot requeue discarded mbuf");
 580                 rte_pktmbuf_free(m);
 581         }
 582 }
 583
 584 static void
 585 virtio_update_packet_stats(struct virtnet_stats *stats, struct rte_mbuf *mbuf)
 586 {
 587         uint32_t s = mbuf->pkt_len;
 588         struct ether_addr *ea;
 589
 590         if (s == 64) {
 591                 stats->size_bins[1]++;
 592         } else if (s > 64 && s < 1024) {
 593                 uint32_t bin;
 594
 595                 /* count zeros, and offset into correct bin */
 596                 bin = (sizeof(s) * 8) - __builtin_clz(s) - 5;
 597                 stats->size_bins[bin]++;
 598         } else {
 599                 if (s < 64)
 600                         stats->size_bins[0]++;
 601                 else if (s < 1519)
 602                         stats->size_bins[6]++;
 603                 else if (s >= 1519)
 604                         stats->size_bins[7]++;
 605         }
 606
 607         ea = rte_pktmbuf_mtod(mbuf, struct ether_addr *);
 608         if (is_multicast_ether_addr(ea)) {
 609                 if (is_broadcast_ether_addr(ea))
 610                         stats->broadcast++;
 611                 else
 612                         stats->multicast++;
 613         }
 614 }
 615
 616 /* Optionally fill offload information in structure */
 617 static int
 618 virtio_rx_offload(struct rte_mbuf *m, struct virtio_net_hdr *hdr)
 619 {
 620         struct rte_net_hdr_lens hdr_lens;
 621         uint32_t hdrlen, ptype;
 622         int l4_supported = 0;
 623
 624         /* nothing to do */
 625         if (hdr->flags == 0 && hdr->gso_type == VIRTIO_NET_HDR_GSO_NONE)
 626                 return 0;
 627
 628         m->ol_flags |= PKT_RX_IP_CKSUM_UNKNOWN;
 629
 630         ptype = rte_net_get_ptype(m, &hdr_lens, RTE_PTYPE_ALL_MASK);
 631         m->packet_type = ptype;
 632         if ((ptype & RTE_PTYPE_L4_MASK) == RTE_PTYPE_L4_TCP ||
 633             (ptype & RTE_PTYPE_L4_MASK) == RTE_PTYPE_L4_UDP ||
 634             (ptype & RTE_PTYPE_L4_MASK) == RTE_PTYPE_L4_SCTP)
 635                 l4_supported = 1;
 636
 637         if (hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
 638                 hdrlen = hdr_lens.l2_len + hdr_lens.l3_len + hdr_lens.l4_len;
 639                 if (hdr->csum_start <= hdrlen && l4_supported) {
 640                         m->ol_flags |= PKT_RX_L4_CKSUM_NONE;
 641                 } else {
 642                         /* Unknown proto or tunnel, do sw cksum. We can assume
 643                          * the cksum field is in the first segment since the
 644                          * buffers we provided to the host are large enough.
 645                          * In case of SCTP, this will be wrong since it's a CRC
 646                          * but there's nothing we can do.
 647                          */
 648                         uint16_t csum = 0, off;
 649
 650                         rte_raw_cksum_mbuf(m, hdr->csum_start,
 651                                 rte_pktmbuf_pkt_len(m) - hdr->csum_start,
 652                                 &csum);
 653                         if (likely(csum != 0xffff))
 654                                 csum = ~csum;
 655                         off = hdr->csum_offset + hdr->csum_start;
 656                         if (rte_pktmbuf_data_len(m) >= off + 1)
 657                                 *rte_pktmbuf_mtod_offset(m, uint16_t *,
 658                                         off) = csum;
 659                 }
 660         } else if (hdr->flags & VIRTIO_NET_HDR_F_DATA_VALID && l4_supported) {
 661                 m->ol_flags |= PKT_RX_L4_CKSUM_GOOD;
 662         }
 663
 664         /* GSO request, save required information in mbuf */
 665         if (hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) {
 666                 /* Check unsupported modes */
 667                 if ((hdr->gso_type & VIRTIO_NET_HDR_GSO_ECN) ||
 668                     (hdr->gso_size == 0)) {
 669                         return -EINVAL;
 670                 }
 671
 672                 /* Update mss lengthes in mbuf */
 673                 m->tso_segsz = hdr->gso_size;
 674                 switch (hdr->gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
 675                         case VIRTIO_NET_HDR_GSO_TCPV4:
 676                         case VIRTIO_NET_HDR_GSO_TCPV6:
 677                                 m->ol_flags |= PKT_RX_LRO | \
 678                                         PKT_RX_L4_CKSUM_NONE;
 679                                 break;
 680                         default:
 681                                 return -EINVAL;
 682                 }
 683         }
 684
 685         return 0;
 686 }
 687
 688 static inline int
 689 rx_offload_enabled(struct virtio_hw *hw)
 690 {
 691         return vtpci_with_feature(hw, VIRTIO_NET_F_GUEST_CSUM) ||
 692                 vtpci_with_feature(hw, VIRTIO_NET_F_GUEST_TSO4) ||
 693                 vtpci_with_feature(hw, VIRTIO_NET_F_GUEST_TSO6);
 694 }
 695
 696 #define VIRTIO_MBUF_BURST_SZ 64
 697 #define DESC_PER_CACHELINE (RTE_CACHE_LINE_SIZE / sizeof(struct vring_desc))
 698 uint16_t
 699 virtio_recv_pkts(void *rx_queue, struct rte_mbuf **rx_pkts, uint16_t nb_pkts)
 700 {
 701         struct virtnet_rx *rxvq = rx_queue;
 702         struct virtqueue *vq = rxvq->vq;
 703         struct virtio_hw *hw = vq->hw;
 704         struct rte_mbuf *rxm, *new_mbuf;
 705         uint16_t nb_used, num, nb_rx;
 706         uint32_t len[VIRTIO_MBUF_BURST_SZ];
 707         struct rte_mbuf *rcv_pkts[VIRTIO_MBUF_BURST_SZ];
 708         int error;
 709         uint32_t i, nb_enqueued;
 710         uint32_t hdr_size;
 711         int offload;
 712         struct virtio_net_hdr *hdr;
 713
 714         nb_rx = 0;
 715         if (unlikely(hw->started == 0))
 716                 return nb_rx;
 717
 718         nb_used = VIRTQUEUE_NUSED(vq);
 719
 720         virtio_rmb();
 721
 722         num = likely(nb_used <= nb_pkts) ? nb_used : nb_pkts;
 723         if (unlikely(num > VIRTIO_MBUF_BURST_SZ))
 724                 num = VIRTIO_MBUF_BURST_SZ;
 725         if (likely(num > DESC_PER_CACHELINE))
 726                 num = num - ((vq->vq_used_cons_idx + num) % DESC_PER_CACHELINE);
 727
 728         num = virtqueue_dequeue_burst_rx(vq, rcv_pkts, len, num);
 729         PMD_RX_LOG(DEBUG, "used:%d dequeue:%d", nb_used, num);
 730
 731         nb_enqueued = 0;
 732         hdr_size = hw->vtnet_hdr_size;
 733         offload = rx_offload_enabled(hw);
 734
 735         for (i = 0; i < num ; i++) {
 736                 rxm = rcv_pkts[i];
 737
 738                 PMD_RX_LOG(DEBUG, "packet len:%d", len[i]);
 739
 740                 if (unlikely(len[i] < hdr_size + ETHER_HDR_LEN)) {
 741                         PMD_RX_LOG(ERR, "Packet drop");
 742                         nb_enqueued++;
 743                         virtio_discard_rxbuf(vq, rxm);
 744                         rxvq->stats.errors++;
 745                         continue;
 746                 }
 747
 748                 rxm->port = rxvq->port_id;
 749                 rxm->data_off = RTE_PKTMBUF_HEADROOM;
 750                 rxm->ol_flags = 0;
 751                 rxm->vlan_tci = 0;
 752
 753                 rxm->pkt_len = (uint32_t)(len[i] - hdr_size);
 754                 rxm->data_len = (uint16_t)(len[i] - hdr_size);
 755
 756                 hdr = (struct virtio_net_hdr *)((char *)rxm->buf_addr +
 757                         RTE_PKTMBUF_HEADROOM - hdr_size);
 758
 759                 if (hw->vlan_strip)
 760                         rte_vlan_strip(rxm);
 761
 762                 if (offload && virtio_rx_offload(rxm, hdr) < 0) {
 763                         virtio_discard_rxbuf(vq, rxm);
 764                         rxvq->stats.errors++;
 765                         continue;
 766                 }
 767
 768                 VIRTIO_DUMP_PACKET(rxm, rxm->data_len);
 769
 770                 rx_pkts[nb_rx++] = rxm;
 771
 772                 rxvq->stats.bytes += rxm->pkt_len;
 773                 virtio_update_packet_stats(&rxvq->stats, rxm);
 774         }
 775
 776         rxvq->stats.packets += nb_rx;
 777
 778         /* Allocate new mbuf for the used descriptor */
 779         error = ENOSPC;
 780         while (likely(!virtqueue_full(vq))) {
 781                 new_mbuf = rte_mbuf_raw_alloc(rxvq->mpool);
 782                 if (unlikely(new_mbuf == NULL)) {
 783                         struct rte_eth_dev *dev
 784                                 = &rte_eth_devices[rxvq->port_id];
 785                         dev->data->rx_mbuf_alloc_failed++;
 786                         break;
 787                 }
 788                 error = virtqueue_enqueue_recv_refill(vq, new_mbuf);
 789                 if (unlikely(error)) {
 790                         rte_pktmbuf_free(new_mbuf);
 791                         break;
 792                 }
 793                 nb_enqueued++;
 794         }
 795
 796         if (likely(nb_enqueued)) {
 797                 vq_update_avail_idx(vq);
 798
 799                 if (unlikely(virtqueue_kick_prepare(vq))) {
 800                         virtqueue_notify(vq);
 801                         PMD_RX_LOG(DEBUG, "Notified");
 802                 }
 803         }
 804
 805         return nb_rx;
 806 }
 807
 808 uint16_t
 809 virtio_recv_mergeable_pkts(void *rx_queue,
 810                         struct rte_mbuf **rx_pkts,
 811                         uint16_t nb_pkts)
 812 {
 813         struct virtnet_rx *rxvq = rx_queue;
 814         struct virtqueue *vq = rxvq->vq;
 815         struct virtio_hw *hw = vq->hw;
 816         struct rte_mbuf *rxm, *new_mbuf;
 817         uint16_t nb_used, num, nb_rx;
 818         uint32_t len[VIRTIO_MBUF_BURST_SZ];
 819         struct rte_mbuf *rcv_pkts[VIRTIO_MBUF_BURST_SZ];
 820         struct rte_mbuf *prev;
 821         int error;
 822         uint32_t i, nb_enqueued;
 823         uint32_t seg_num;
 824         uint16_t extra_idx;
 825         uint32_t seg_res;
 826         uint32_t hdr_size;
 827         int offload;
 828
 829         nb_rx = 0;
 830         if (unlikely(hw->started == 0))
 831                 return nb_rx;
 832
 833         nb_used = VIRTQUEUE_NUSED(vq);
 834
 835         virtio_rmb();
 836
 837         PMD_RX_LOG(DEBUG, "used:%d", nb_used);
 838
 839         i = 0;
 840         nb_enqueued = 0;
 841         seg_num = 0;
 842         extra_idx = 0;
 843         seg_res = 0;
 844         hdr_size = hw->vtnet_hdr_size;
 845         offload = rx_offload_enabled(hw);
 846
 847         while (i < nb_used) {
 848                 struct virtio_net_hdr_mrg_rxbuf *header;
 849
 850                 if (nb_rx == nb_pkts)
 851                         break;
 852
 853                 num = virtqueue_dequeue_burst_rx(vq, rcv_pkts, len, 1);
 854                 if (num != 1)
 855                         continue;
 856
 857                 i++;
 858
 859                 PMD_RX_LOG(DEBUG, "dequeue:%d", num);
 860                 PMD_RX_LOG(DEBUG, "packet len:%d", len[0]);
 861
 862                 rxm = rcv_pkts[0];
 863
 864                 if (unlikely(len[0] < hdr_size + ETHER_HDR_LEN)) {
 865                         PMD_RX_LOG(ERR, "Packet drop");
 866                         nb_enqueued++;
 867                         virtio_discard_rxbuf(vq, rxm);
 868                         rxvq->stats.errors++;
 869                         continue;
 870                 }
 871
 872                 header = (struct virtio_net_hdr_mrg_rxbuf *)((char *)rxm->buf_addr +
 873                         RTE_PKTMBUF_HEADROOM - hdr_size);
 874                 seg_num = header->num_buffers;
 875
 876                 if (seg_num == 0)
 877                         seg_num = 1;
 878
 879                 rxm->data_off = RTE_PKTMBUF_HEADROOM;
 880                 rxm->nb_segs = seg_num;
 881                 rxm->ol_flags = 0;
 882                 rxm->vlan_tci = 0;
 883                 rxm->pkt_len = (uint32_t)(len[0] - hdr_size);
 884                 rxm->data_len = (uint16_t)(len[0] - hdr_size);
 885
 886                 rxm->port = rxvq->port_id;
 887                 rx_pkts[nb_rx] = rxm;
 888                 prev = rxm;
 889
 890                 if (offload && virtio_rx_offload(rxm, &header->hdr) < 0) {
 891                         virtio_discard_rxbuf(vq, rxm);
 892                         rxvq->stats.errors++;
 893                         continue;
 894                 }
 895
 896                 seg_res = seg_num - 1;
 897
 898                 while (seg_res != 0) {
 899                         /*
 900                          * Get extra segments for current uncompleted packet.
 901                          */
 902                         uint16_t  rcv_cnt =
 903                                 RTE_MIN(seg_res, RTE_DIM(rcv_pkts));
 904                         if (likely(VIRTQUEUE_NUSED(vq) >= rcv_cnt)) {
 905                                 uint32_t rx_num =
 906                                         virtqueue_dequeue_burst_rx(vq,
 907                                         rcv_pkts, len, rcv_cnt);
 908                                 i += rx_num;
 909                                 rcv_cnt = rx_num;
 910                         } else {
 911                                 PMD_RX_LOG(ERR,
 912                                            "No enough segments for packet.");
 913                                 nb_enqueued++;
 914                                 virtio_discard_rxbuf(vq, rxm);
 915                                 rxvq->stats.errors++;
 916                                 break;
 917                         }
 918
 919                         extra_idx = 0;
 920
 921                         while (extra_idx < rcv_cnt) {
 922                                 rxm = rcv_pkts[extra_idx];
 923
 924                                 rxm->data_off = RTE_PKTMBUF_HEADROOM - hdr_size;
 925                                 rxm->pkt_len = (uint32_t)(len[extra_idx]);
 926                                 rxm->data_len = (uint16_t)(len[extra_idx]);
 927
 928                                 if (prev)
 929                                         prev->next = rxm;
 930
 931                                 prev = rxm;
 932                                 rx_pkts[nb_rx]->pkt_len += rxm->pkt_len;
 933                                 extra_idx++;
 934                         };
 935                         seg_res -= rcv_cnt;
 936                 }
 937
 938                 if (hw->vlan_strip)
 939                         rte_vlan_strip(rx_pkts[nb_rx]);
 940
 941                 VIRTIO_DUMP_PACKET(rx_pkts[nb_rx],
 942                         rx_pkts[nb_rx]->data_len);
 943
 944                 rxvq->stats.bytes += rx_pkts[nb_rx]->pkt_len;
 945                 virtio_update_packet_stats(&rxvq->stats, rx_pkts[nb_rx]);
 946                 nb_rx++;
 947         }
 948
 949         rxvq->stats.packets += nb_rx;
 950
 951         /* Allocate new mbuf for the used descriptor */
 952         error = ENOSPC;
 953         while (likely(!virtqueue_full(vq))) {
 954                 new_mbuf = rte_mbuf_raw_alloc(rxvq->mpool);
 955                 if (unlikely(new_mbuf == NULL)) {
 956                         struct rte_eth_dev *dev
 957                                 = &rte_eth_devices[rxvq->port_id];
 958                         dev->data->rx_mbuf_alloc_failed++;
 959                         break;
 960                 }
 961                 error = virtqueue_enqueue_recv_refill(vq, new_mbuf);
 962                 if (unlikely(error)) {
 963                         rte_pktmbuf_free(new_mbuf);
 964                         break;
 965                 }
 966                 nb_enqueued++;
 967         }
 968
 969         if (likely(nb_enqueued)) {
 970                 vq_update_avail_idx(vq);
 971
 972                 if (unlikely(virtqueue_kick_prepare(vq))) {
 973                         virtqueue_notify(vq);
 974                         PMD_RX_LOG(DEBUG, "Notified");
 975                 }
 976         }
 977
 978         return nb_rx;
 979 }
 980
 981 uint16_t
 982 virtio_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts, uint16_t nb_pkts)
 983 {
 984         struct virtnet_tx *txvq = tx_queue;
 985         struct virtqueue *vq = txvq->vq;
 986         struct virtio_hw *hw = vq->hw;
 987         uint16_t hdr_size = hw->vtnet_hdr_size;
 988         uint16_t nb_used, nb_tx = 0;
 989         int error;
 990
 991         if (unlikely(hw->started == 0))
 992                 return nb_tx;
 993
 994         if (unlikely(nb_pkts < 1))
 995                 return nb_pkts;
 996
 997         PMD_TX_LOG(DEBUG, "%d packets to xmit", nb_pkts);
 998         nb_used = VIRTQUEUE_NUSED(vq);
 999
1000         virtio_rmb();
1001         if (likely(nb_used > vq->vq_nentries - vq->vq_free_thresh))
1002                 virtio_xmit_cleanup(vq, nb_used);
1003
1004         for (nb_tx = 0; nb_tx < nb_pkts; nb_tx++) {
1005                 struct rte_mbuf *txm = tx_pkts[nb_tx];
1006                 int can_push = 0, use_indirect = 0, slots, need;
1007
1008                 /* Do VLAN tag insertion */
1009                 if (unlikely(txm->ol_flags & PKT_TX_VLAN_PKT)) {
1010                         error = rte_vlan_insert(&txm);
1011                         if (unlikely(error)) {
1012                                 rte_pktmbuf_free(txm);
1013                                 continue;
1014                         }
1015                 }
1016
1017                 /* optimize ring usage */
1018                 if ((vtpci_with_feature(hw, VIRTIO_F_ANY_LAYOUT) ||
1019                       vtpci_with_feature(hw, VIRTIO_F_VERSION_1)) &&
1020                     rte_mbuf_refcnt_read(txm) == 1 &&
1021                     RTE_MBUF_DIRECT(txm) &&
1022                     txm->nb_segs == 1 &&
1023                     rte_pktmbuf_headroom(txm) >= hdr_size &&
1024                     rte_is_aligned(rte_pktmbuf_mtod(txm, char *),
1025                                    __alignof__(struct virtio_net_hdr_mrg_rxbuf)))
1026                         can_push = 1;
1027                 else if (vtpci_with_feature(hw, VIRTIO_RING_F_INDIRECT_DESC) &&
1028                          txm->nb_segs < VIRTIO_MAX_TX_INDIRECT)
1029                         use_indirect = 1;
1030
1031                 /* How many main ring entries are needed to this Tx?
1032                  * any_layout => number of segments
1033                  * indirect   => 1
1034                  * default    => number of segments + 1
1035                  */
1036                 slots = use_indirect ? 1 : (txm->nb_segs + !can_push);
1037                 need = slots - vq->vq_free_cnt;
1038
1039                 /* Positive value indicates it need free vring descriptors */
1040                 if (unlikely(need > 0)) {
1041                         nb_used = VIRTQUEUE_NUSED(vq);
1042                         virtio_rmb();
1043                         need = RTE_MIN(need, (int)nb_used);
1044
1045                         virtio_xmit_cleanup(vq, need);
1046                         need = slots - vq->vq_free_cnt;
1047                         if (unlikely(need > 0)) {
1048                                 PMD_TX_LOG(ERR,
1049                                            "No free tx descriptors to transmit");
1050                                 break;
1051                         }
1052                 }
1053
1054                 /* Enqueue Packet buffers */
1055                 virtqueue_enqueue_xmit(txvq, txm, slots, use_indirect, can_push);
1056
1057                 txvq->stats.bytes += txm->pkt_len;
1058                 virtio_update_packet_stats(&txvq->stats, txm);
1059         }
1060
1061         txvq->stats.packets += nb_tx;
1062
1063         if (likely(nb_tx)) {
1064                 vq_update_avail_idx(vq);
1065
1066                 if (unlikely(virtqueue_kick_prepare(vq))) {
1067                         virtqueue_notify(vq);
1068                         PMD_TX_LOG(DEBUG, "Notified backend after xmit");
1069                 }
1070         }
1071
1072         return nb_tx;
1073 }