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_driver.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 #include "virtio_rxtx_simple.h"
  34
  35 #ifdef RTE_LIBRTE_VIRTIO_DEBUG_DUMP
  36 #define VIRTIO_DUMP_PACKET(m, len) rte_pktmbuf_dump(stdout, m, len)
  37 #else
  38 #define  VIRTIO_DUMP_PACKET(m, len) do { } while (0)
  39 #endif
  40
  41
  42 #define VIRTIO_SIMPLE_FLAGS ((uint32_t)ETH_TXQ_FLAGS_NOMULTSEGS | \
  43         ETH_TXQ_FLAGS_NOOFFLOADS)
  44
  45 int
  46 virtio_dev_rx_queue_done(void *rxq, uint16_t offset)
  47 {
  48         struct virtnet_rx *rxvq = rxq;
  49         struct virtqueue *vq = rxvq->vq;
  50
  51         return VIRTQUEUE_NUSED(vq) >= offset;
  52 }
  53
  54 void
  55 vq_ring_free_chain(struct virtqueue *vq, uint16_t desc_idx)
  56 {
  57         struct vring_desc *dp, *dp_tail;
  58         struct vq_desc_extra *dxp;
  59         uint16_t desc_idx_last = desc_idx;
  60
  61         dp  = &vq->vq_ring.desc[desc_idx];
  62         dxp = &vq->vq_descx[desc_idx];
  63         vq->vq_free_cnt = (uint16_t)(vq->vq_free_cnt + dxp->ndescs);
  64         if ((dp->flags & VRING_DESC_F_INDIRECT) == 0) {
  65                 while (dp->flags & VRING_DESC_F_NEXT) {
  66                         desc_idx_last = dp->next;
  67                         dp = &vq->vq_ring.desc[dp->next];
  68                 }
  69         }
  70         dxp->ndescs = 0;
  71
  72         /*
  73          * We must append the existing free chain, if any, to the end of
  74          * newly freed chain. If the virtqueue was completely used, then
  75          * head would be VQ_RING_DESC_CHAIN_END (ASSERTed above).
  76          */
  77         if (vq->vq_desc_tail_idx == VQ_RING_DESC_CHAIN_END) {
  78                 vq->vq_desc_head_idx = desc_idx;
  79         } else {
  80                 dp_tail = &vq->vq_ring.desc[vq->vq_desc_tail_idx];
  81                 dp_tail->next = desc_idx;
  82         }
  83
  84         vq->vq_desc_tail_idx = desc_idx_last;
  85         dp->next = VQ_RING_DESC_CHAIN_END;
  86 }
  87
  88 static uint16_t
  89 virtqueue_dequeue_burst_rx(struct virtqueue *vq, struct rte_mbuf **rx_pkts,
  90                            uint32_t *len, uint16_t num)
  91 {
  92         struct vring_used_elem *uep;
  93         struct rte_mbuf *cookie;
  94         uint16_t used_idx, desc_idx;
  95         uint16_t i;
  96
  97         /*  Caller does the check */
  98         for (i = 0; i < num ; i++) {
  99                 used_idx = (uint16_t)(vq->vq_used_cons_idx & (vq->vq_nentries - 1));
 100                 uep = &vq->vq_ring.used->ring[used_idx];
 101                 desc_idx = (uint16_t) uep->id;
 102                 len[i] = uep->len;
 103                 cookie = (struct rte_mbuf *)vq->vq_descx[desc_idx].cookie;
 104
 105                 if (unlikely(cookie == NULL)) {
 106                         PMD_DRV_LOG(ERR, "vring descriptor with no mbuf cookie at %u",
 107                                 vq->vq_used_cons_idx);
 108                         break;
 109                 }
 110
 111                 rte_prefetch0(cookie);
 112                 rte_packet_prefetch(rte_pktmbuf_mtod(cookie, void *));
 113                 rx_pkts[i]  = cookie;
 114                 vq->vq_used_cons_idx++;
 115                 vq_ring_free_chain(vq, desc_idx);
 116                 vq->vq_descx[desc_idx].cookie = NULL;
 117         }
 118
 119         return i;
 120 }
 121
 122 #ifndef DEFAULT_TX_FREE_THRESH
 123 #define DEFAULT_TX_FREE_THRESH 32
 124 #endif
 125
 126 /* Cleanup from completed transmits. */
 127 static void
 128 virtio_xmit_cleanup(struct virtqueue *vq, uint16_t num)
 129 {
 130         uint16_t i, used_idx, desc_idx;
 131         for (i = 0; i < num; i++) {
 132                 struct vring_used_elem *uep;
 133                 struct vq_desc_extra *dxp;
 134
 135                 used_idx = (uint16_t)(vq->vq_used_cons_idx & (vq->vq_nentries - 1));
 136                 uep = &vq->vq_ring.used->ring[used_idx];
 137
 138                 desc_idx = (uint16_t) uep->id;
 139                 dxp = &vq->vq_descx[desc_idx];
 140                 vq->vq_used_cons_idx++;
 141                 vq_ring_free_chain(vq, desc_idx);
 142
 143                 if (dxp->cookie != NULL) {
 144                         rte_pktmbuf_free(dxp->cookie);
 145                         dxp->cookie = NULL;
 146                 }
 147         }
 148 }
 149
 150
 151 static inline int
 152 virtqueue_enqueue_recv_refill(struct virtqueue *vq, struct rte_mbuf *cookie)
 153 {
 154         struct vq_desc_extra *dxp;
 155         struct virtio_hw *hw = vq->hw;
 156         struct vring_desc *start_dp;
 157         uint16_t needed = 1;
 158         uint16_t head_idx, idx;
 159
 160         if (unlikely(vq->vq_free_cnt == 0))
 161                 return -ENOSPC;
 162         if (unlikely(vq->vq_free_cnt < needed))
 163                 return -EMSGSIZE;
 164
 165         head_idx = vq->vq_desc_head_idx;
 166         if (unlikely(head_idx >= vq->vq_nentries))
 167                 return -EFAULT;
 168
 169         idx = head_idx;
 170         dxp = &vq->vq_descx[idx];
 171         dxp->cookie = (void *)cookie;
 172         dxp->ndescs = needed;
 173
 174         start_dp = vq->vq_ring.desc;
 175         start_dp[idx].addr =
 176                 VIRTIO_MBUF_ADDR(cookie, vq) +
 177                 RTE_PKTMBUF_HEADROOM - hw->vtnet_hdr_size;
 178         start_dp[idx].len =
 179                 cookie->buf_len - RTE_PKTMBUF_HEADROOM + hw->vtnet_hdr_size;
 180         start_dp[idx].flags =  VRING_DESC_F_WRITE;
 181         idx = start_dp[idx].next;
 182         vq->vq_desc_head_idx = idx;
 183         if (vq->vq_desc_head_idx == VQ_RING_DESC_CHAIN_END)
 184                 vq->vq_desc_tail_idx = idx;
 185         vq->vq_free_cnt = (uint16_t)(vq->vq_free_cnt - needed);
 186         vq_update_avail_ring(vq, head_idx);
 187
 188         return 0;
 189 }
 190
 191 /* When doing TSO, the IP length is not included in the pseudo header
 192  * checksum of the packet given to the PMD, but for virtio it is
 193  * expected.
 194  */
 195 static void
 196 virtio_tso_fix_cksum(struct rte_mbuf *m)
 197 {
 198         /* common case: header is not fragmented */
 199         if (likely(rte_pktmbuf_data_len(m) >= m->l2_len + m->l3_len +
 200                         m->l4_len)) {
 201                 struct ipv4_hdr *iph;
 202                 struct ipv6_hdr *ip6h;
 203                 struct tcp_hdr *th;
 204                 uint16_t prev_cksum, new_cksum, ip_len, ip_paylen;
 205                 uint32_t tmp;
 206
 207                 iph = rte_pktmbuf_mtod_offset(m, struct ipv4_hdr *, m->l2_len);
 208                 th = RTE_PTR_ADD(iph, m->l3_len);
 209                 if ((iph->version_ihl >> 4) == 4) {
 210                         iph->hdr_checksum = 0;
 211                         iph->hdr_checksum = rte_ipv4_cksum(iph);
 212                         ip_len = iph->total_length;
 213                         ip_paylen = rte_cpu_to_be_16(rte_be_to_cpu_16(ip_len) -
 214                                 m->l3_len);
 215                 } else {
 216                         ip6h = (struct ipv6_hdr *)iph;
 217                         ip_paylen = ip6h->payload_len;
 218                 }
 219
 220                 /* calculate the new phdr checksum not including ip_paylen */
 221                 prev_cksum = th->cksum;
 222                 tmp = prev_cksum;
 223                 tmp += ip_paylen;
 224                 tmp = (tmp & 0xffff) + (tmp >> 16);
 225                 new_cksum = tmp;
 226
 227                 /* replace it in the packet */
 228                 th->cksum = new_cksum;
 229         }
 230 }
 231
 232 static inline int
 233 tx_offload_enabled(struct virtio_hw *hw)
 234 {
 235         return vtpci_with_feature(hw, VIRTIO_NET_F_CSUM) ||
 236                 vtpci_with_feature(hw, VIRTIO_NET_F_HOST_TSO4) ||
 237                 vtpci_with_feature(hw, VIRTIO_NET_F_HOST_TSO6);
 238 }
 239
 240 /* avoid write operation when necessary, to lessen cache issues */
 241 #define ASSIGN_UNLESS_EQUAL(var, val) do {      \
 242         if ((var) != (val))                     \
 243                 (var) = (val);                  \
 244 } while (0)
 245
 246 static inline void
 247 virtqueue_enqueue_xmit(struct virtnet_tx *txvq, struct rte_mbuf *cookie,
 248                        uint16_t needed, int use_indirect, int can_push)
 249 {
 250         struct virtio_tx_region *txr = txvq->virtio_net_hdr_mz->addr;
 251         struct vq_desc_extra *dxp;
 252         struct virtqueue *vq = txvq->vq;
 253         struct vring_desc *start_dp;
 254         uint16_t seg_num = cookie->nb_segs;
 255         uint16_t head_idx, idx;
 256         uint16_t head_size = vq->hw->vtnet_hdr_size;
 257         struct virtio_net_hdr *hdr;
 258         int offload;
 259
 260         offload = tx_offload_enabled(vq->hw);
 261         head_idx = vq->vq_desc_head_idx;
 262         idx = head_idx;
 263         dxp = &vq->vq_descx[idx];
 264         dxp->cookie = (void *)cookie;
 265         dxp->ndescs = needed;
 266
 267         start_dp = vq->vq_ring.desc;
 268
 269         if (can_push) {
 270                 /* prepend cannot fail, checked by caller */
 271                 hdr = (struct virtio_net_hdr *)
 272                         rte_pktmbuf_prepend(cookie, head_size);
 273                 /* rte_pktmbuf_prepend() counts the hdr size to the pkt length,
 274                  * which is wrong. Below subtract restores correct pkt size.
 275                  */
 276                 cookie->pkt_len -= head_size;
 277                 /* if offload disabled, it is not zeroed below, do it now */
 278                 if (offload == 0) {
 279                         ASSIGN_UNLESS_EQUAL(hdr->csum_start, 0);
 280                         ASSIGN_UNLESS_EQUAL(hdr->csum_offset, 0);
 281                         ASSIGN_UNLESS_EQUAL(hdr->flags, 0);
 282                         ASSIGN_UNLESS_EQUAL(hdr->gso_type, 0);
 283                         ASSIGN_UNLESS_EQUAL(hdr->gso_size, 0);
 284                         ASSIGN_UNLESS_EQUAL(hdr->hdr_len, 0);
 285                 }
 286         } else if (use_indirect) {
 287                 /* setup tx ring slot to point to indirect
 288                  * descriptor list stored in reserved region.
 289                  *
 290                  * the first slot in indirect ring is already preset
 291                  * to point to the header in reserved region
 292                  */
 293                 start_dp[idx].addr  = txvq->virtio_net_hdr_mem +
 294                         RTE_PTR_DIFF(&txr[idx].tx_indir, txr);
 295                 start_dp[idx].len   = (seg_num + 1) * sizeof(struct vring_desc);
 296                 start_dp[idx].flags = VRING_DESC_F_INDIRECT;
 297                 hdr = (struct virtio_net_hdr *)&txr[idx].tx_hdr;
 298
 299                 /* loop below will fill in rest of the indirect elements */
 300                 start_dp = txr[idx].tx_indir;
 301                 idx = 1;
 302         } else {
 303                 /* setup first tx ring slot to point to header
 304                  * stored in reserved region.
 305                  */
 306                 start_dp[idx].addr  = txvq->virtio_net_hdr_mem +
 307                         RTE_PTR_DIFF(&txr[idx].tx_hdr, txr);
 308                 start_dp[idx].len   = vq->hw->vtnet_hdr_size;
 309                 start_dp[idx].flags = VRING_DESC_F_NEXT;
 310                 hdr = (struct virtio_net_hdr *)&txr[idx].tx_hdr;
 311
 312                 idx = start_dp[idx].next;
 313         }
 314
 315         /* Checksum Offload / TSO */
 316         if (offload) {
 317                 if (cookie->ol_flags & PKT_TX_TCP_SEG)
 318                         cookie->ol_flags |= PKT_TX_TCP_CKSUM;
 319
 320                 switch (cookie->ol_flags & PKT_TX_L4_MASK) {
 321                 case PKT_TX_UDP_CKSUM:
 322                         hdr->csum_start = cookie->l2_len + cookie->l3_len;
 323                         hdr->csum_offset = offsetof(struct udp_hdr,
 324                                 dgram_cksum);
 325                         hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
 326                         break;
 327
 328                 case PKT_TX_TCP_CKSUM:
 329                         hdr->csum_start = cookie->l2_len + cookie->l3_len;
 330                         hdr->csum_offset = offsetof(struct tcp_hdr, cksum);
 331                         hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
 332                         break;
 333
 334                 default:
 335                         ASSIGN_UNLESS_EQUAL(hdr->csum_start, 0);
 336                         ASSIGN_UNLESS_EQUAL(hdr->csum_offset, 0);
 337                         ASSIGN_UNLESS_EQUAL(hdr->flags, 0);
 338                         break;
 339                 }
 340
 341                 /* TCP Segmentation Offload */
 342                 if (cookie->ol_flags & PKT_TX_TCP_SEG) {
 343                         virtio_tso_fix_cksum(cookie);
 344                         hdr->gso_type = (cookie->ol_flags & PKT_TX_IPV6) ?
 345                                 VIRTIO_NET_HDR_GSO_TCPV6 :
 346                                 VIRTIO_NET_HDR_GSO_TCPV4;
 347                         hdr->gso_size = cookie->tso_segsz;
 348                         hdr->hdr_len =
 349                                 cookie->l2_len +
 350                                 cookie->l3_len +
 351                                 cookie->l4_len;
 352                 } else {
 353                         ASSIGN_UNLESS_EQUAL(hdr->gso_type, 0);
 354                         ASSIGN_UNLESS_EQUAL(hdr->gso_size, 0);
 355                         ASSIGN_UNLESS_EQUAL(hdr->hdr_len, 0);
 356                 }
 357         }
 358
 359         do {
 360                 start_dp[idx].addr  = VIRTIO_MBUF_DATA_DMA_ADDR(cookie, vq);
 361                 start_dp[idx].len   = cookie->data_len;
 362                 start_dp[idx].flags = cookie->next ? VRING_DESC_F_NEXT : 0;
 363                 idx = start_dp[idx].next;
 364         } while ((cookie = cookie->next) != NULL);
 365
 366         if (use_indirect)
 367                 idx = vq->vq_ring.desc[head_idx].next;
 368
 369         vq->vq_desc_head_idx = idx;
 370         if (vq->vq_desc_head_idx == VQ_RING_DESC_CHAIN_END)
 371                 vq->vq_desc_tail_idx = idx;
 372         vq->vq_free_cnt = (uint16_t)(vq->vq_free_cnt - needed);
 373         vq_update_avail_ring(vq, head_idx);
 374 }
 375
 376 void
 377 virtio_dev_cq_start(struct rte_eth_dev *dev)
 378 {
 379         struct virtio_hw *hw = dev->data->dev_private;
 380
 381         if (hw->cvq && hw->cvq->vq) {
 382                 rte_spinlock_init(&hw->cvq->lock);
 383                 VIRTQUEUE_DUMP((struct virtqueue *)hw->cvq->vq);
 384         }
 385 }
 386
 387 int
 388 virtio_dev_rx_queue_setup(struct rte_eth_dev *dev,
 389                         uint16_t queue_idx,
 390                         uint16_t nb_desc,
 391                         unsigned int socket_id __rte_unused,
 392                         __rte_unused const struct rte_eth_rxconf *rx_conf,
 393                         struct rte_mempool *mp)
 394 {
 395         uint16_t vtpci_queue_idx = 2 * queue_idx + VTNET_SQ_RQ_QUEUE_IDX;
 396         struct virtio_hw *hw = dev->data->dev_private;
 397         struct virtqueue *vq = hw->vqs[vtpci_queue_idx];
 398         struct virtnet_rx *rxvq;
 399
 400         PMD_INIT_FUNC_TRACE();
 401
 402         if (nb_desc == 0 || nb_desc > vq->vq_nentries)
 403                 nb_desc = vq->vq_nentries;
 404         vq->vq_free_cnt = RTE_MIN(vq->vq_free_cnt, nb_desc);
 405
 406         rxvq = &vq->rxq;
 407         rxvq->queue_id = queue_idx;
 408         rxvq->mpool = mp;
 409         if (rxvq->mpool == NULL) {
 410                 rte_exit(EXIT_FAILURE,
 411                         "Cannot allocate mbufs for rx virtqueue");
 412         }
 413         dev->data->rx_queues[queue_idx] = rxvq;
 414
 415         return 0;
 416 }
 417
 418 int
 419 virtio_dev_rx_queue_setup_finish(struct rte_eth_dev *dev, uint16_t queue_idx)
 420 {
 421         uint16_t vtpci_queue_idx = 2 * queue_idx + VTNET_SQ_RQ_QUEUE_IDX;
 422         struct virtio_hw *hw = dev->data->dev_private;
 423         struct virtqueue *vq = hw->vqs[vtpci_queue_idx];
 424         struct virtnet_rx *rxvq = &vq->rxq;
 425         struct rte_mbuf *m;
 426         uint16_t desc_idx;
 427         int error, nbufs;
 428
 429         PMD_INIT_FUNC_TRACE();
 430
 431         /* Allocate blank mbufs for the each rx descriptor */
 432         nbufs = 0;
 433
 434         if (hw->use_simple_rx) {
 435                 for (desc_idx = 0; desc_idx < vq->vq_nentries;
 436                      desc_idx++) {
 437                         vq->vq_ring.avail->ring[desc_idx] = desc_idx;
 438                         vq->vq_ring.desc[desc_idx].flags =
 439                                 VRING_DESC_F_WRITE;
 440                 }
 441
 442                 virtio_rxq_vec_setup(rxvq);
 443         }
 444
 445         memset(&rxvq->fake_mbuf, 0, sizeof(rxvq->fake_mbuf));
 446         for (desc_idx = 0; desc_idx < RTE_PMD_VIRTIO_RX_MAX_BURST;
 447              desc_idx++) {
 448                 vq->sw_ring[vq->vq_nentries + desc_idx] =
 449                         &rxvq->fake_mbuf;
 450         }
 451
 452         if (hw->use_simple_rx) {
 453                 while (vq->vq_free_cnt >= RTE_VIRTIO_VPMD_RX_REARM_THRESH) {
 454                         virtio_rxq_rearm_vec(rxvq);
 455                         nbufs += RTE_VIRTIO_VPMD_RX_REARM_THRESH;
 456                 }
 457         } else {
 458                 while (!virtqueue_full(vq)) {
 459                         m = rte_mbuf_raw_alloc(rxvq->mpool);
 460                         if (m == NULL)
 461                                 break;
 462
 463                         /* Enqueue allocated buffers */
 464                         error = virtqueue_enqueue_recv_refill(vq, m);
 465                         if (error) {
 466                                 rte_pktmbuf_free(m);
 467                                 break;
 468                         }
 469                         nbufs++;
 470                 }
 471
 472                 vq_update_avail_idx(vq);
 473         }
 474
 475         PMD_INIT_LOG(DEBUG, "Allocated %d bufs", nbufs);
 476
 477         VIRTQUEUE_DUMP(vq);
 478
 479         return 0;
 480 }
 481
 482 /*
 483  * struct rte_eth_dev *dev: Used to update dev
 484  * uint16_t nb_desc: Defaults to values read from config space
 485  * unsigned int socket_id: Used to allocate memzone
 486  * const struct rte_eth_txconf *tx_conf: Used to setup tx engine
 487  * uint16_t queue_idx: Just used as an index in dev txq list
 488  */
 489 int
 490 virtio_dev_tx_queue_setup(struct rte_eth_dev *dev,
 491                         uint16_t queue_idx,
 492                         uint16_t nb_desc,
 493                         unsigned int socket_id __rte_unused,
 494                         const struct rte_eth_txconf *tx_conf)
 495 {
 496         uint8_t vtpci_queue_idx = 2 * queue_idx + VTNET_SQ_TQ_QUEUE_IDX;
 497         struct virtio_hw *hw = dev->data->dev_private;
 498         struct virtqueue *vq = hw->vqs[vtpci_queue_idx];
 499         struct virtnet_tx *txvq;
 500         uint16_t tx_free_thresh;
 501
 502         PMD_INIT_FUNC_TRACE();
 503
 504         /* cannot use simple rxtx funcs with multisegs or offloads */
 505         if ((tx_conf->txq_flags & VIRTIO_SIMPLE_FLAGS) != VIRTIO_SIMPLE_FLAGS)
 506                 hw->use_simple_tx = 0;
 507
 508         if (nb_desc == 0 || nb_desc > vq->vq_nentries)
 509                 nb_desc = vq->vq_nentries;
 510         vq->vq_free_cnt = RTE_MIN(vq->vq_free_cnt, nb_desc);
 511
 512         txvq = &vq->txq;
 513         txvq->queue_id = queue_idx;
 514
 515         tx_free_thresh = tx_conf->tx_free_thresh;
 516         if (tx_free_thresh == 0)
 517                 tx_free_thresh =
 518                         RTE_MIN(vq->vq_nentries / 4, DEFAULT_TX_FREE_THRESH);
 519
 520         if (tx_free_thresh >= (vq->vq_nentries - 3)) {
 521                 RTE_LOG(ERR, PMD, "tx_free_thresh must be less than the "
 522                         "number of TX entries minus 3 (%u)."
 523                         " (tx_free_thresh=%u port=%u queue=%u)\n",
 524                         vq->vq_nentries - 3,
 525                         tx_free_thresh, dev->data->port_id, queue_idx);
 526                 return -EINVAL;
 527         }
 528
 529         vq->vq_free_thresh = tx_free_thresh;
 530
 531         dev->data->tx_queues[queue_idx] = txvq;
 532         return 0;
 533 }
 534
 535 int
 536 virtio_dev_tx_queue_setup_finish(struct rte_eth_dev *dev,
 537                                 uint16_t queue_idx)
 538 {
 539         uint8_t vtpci_queue_idx = 2 * queue_idx + VTNET_SQ_TQ_QUEUE_IDX;
 540         struct virtio_hw *hw = dev->data->dev_private;
 541         struct virtqueue *vq = hw->vqs[vtpci_queue_idx];
 542         uint16_t mid_idx = vq->vq_nentries >> 1;
 543         struct virtnet_tx *txvq = &vq->txq;
 544         uint16_t desc_idx;
 545
 546         PMD_INIT_FUNC_TRACE();
 547
 548         if (hw->use_simple_tx) {
 549                 for (desc_idx = 0; desc_idx < mid_idx; desc_idx++) {
 550                         vq->vq_ring.avail->ring[desc_idx] =
 551                                 desc_idx + mid_idx;
 552                         vq->vq_ring.desc[desc_idx + mid_idx].next =
 553                                 desc_idx;
 554                         vq->vq_ring.desc[desc_idx + mid_idx].addr =
 555                                 txvq->virtio_net_hdr_mem +
 556                                 offsetof(struct virtio_tx_region, tx_hdr);
 557                         vq->vq_ring.desc[desc_idx + mid_idx].len =
 558                                 vq->hw->vtnet_hdr_size;
 559                         vq->vq_ring.desc[desc_idx + mid_idx].flags =
 560                                 VRING_DESC_F_NEXT;
 561                         vq->vq_ring.desc[desc_idx].flags = 0;
 562                 }
 563                 for (desc_idx = mid_idx; desc_idx < vq->vq_nentries;
 564                      desc_idx++)
 565                         vq->vq_ring.avail->ring[desc_idx] = desc_idx;
 566         }
 567
 568         VIRTQUEUE_DUMP(vq);
 569
 570         return 0;
 571 }
 572
 573 static void
 574 virtio_discard_rxbuf(struct virtqueue *vq, struct rte_mbuf *m)
 575 {
 576         int error;
 577         /*
 578          * Requeue the discarded mbuf. This should always be
 579          * successful since it was just dequeued.
 580          */
 581         error = virtqueue_enqueue_recv_refill(vq, m);
 582         if (unlikely(error)) {
 583                 RTE_LOG(ERR, PMD, "cannot requeue discarded mbuf");
 584                 rte_pktmbuf_free(m);
 585         }
 586 }
 587
 588 static void
 589 virtio_update_packet_stats(struct virtnet_stats *stats, struct rte_mbuf *mbuf)
 590 {
 591         uint32_t s = mbuf->pkt_len;
 592         struct ether_addr *ea;
 593
 594         if (s == 64) {
 595                 stats->size_bins[1]++;
 596         } else if (s > 64 && s < 1024) {
 597                 uint32_t bin;
 598
 599                 /* count zeros, and offset into correct bin */
 600                 bin = (sizeof(s) * 8) - __builtin_clz(s) - 5;
 601                 stats->size_bins[bin]++;
 602         } else {
 603                 if (s < 64)
 604                         stats->size_bins[0]++;
 605                 else if (s < 1519)
 606                         stats->size_bins[6]++;
 607                 else if (s >= 1519)
 608                         stats->size_bins[7]++;
 609         }
 610
 611         ea = rte_pktmbuf_mtod(mbuf, struct ether_addr *);
 612         if (is_multicast_ether_addr(ea)) {
 613                 if (is_broadcast_ether_addr(ea))
 614                         stats->broadcast++;
 615                 else
 616                         stats->multicast++;
 617         }
 618 }
 619
 620 /* Optionally fill offload information in structure */
 621 static int
 622 virtio_rx_offload(struct rte_mbuf *m, struct virtio_net_hdr *hdr)
 623 {
 624         struct rte_net_hdr_lens hdr_lens;
 625         uint32_t hdrlen, ptype;
 626         int l4_supported = 0;
 627
 628         /* nothing to do */
 629         if (hdr->flags == 0 && hdr->gso_type == VIRTIO_NET_HDR_GSO_NONE)
 630                 return 0;
 631
 632         m->ol_flags |= PKT_RX_IP_CKSUM_UNKNOWN;
 633
 634         ptype = rte_net_get_ptype(m, &hdr_lens, RTE_PTYPE_ALL_MASK);
 635         m->packet_type = ptype;
 636         if ((ptype & RTE_PTYPE_L4_MASK) == RTE_PTYPE_L4_TCP ||
 637             (ptype & RTE_PTYPE_L4_MASK) == RTE_PTYPE_L4_UDP ||
 638             (ptype & RTE_PTYPE_L4_MASK) == RTE_PTYPE_L4_SCTP)
 639                 l4_supported = 1;
 640
 641         if (hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
 642                 hdrlen = hdr_lens.l2_len + hdr_lens.l3_len + hdr_lens.l4_len;
 643                 if (hdr->csum_start <= hdrlen && l4_supported) {
 644                         m->ol_flags |= PKT_RX_L4_CKSUM_NONE;
 645                 } else {
 646                         /* Unknown proto or tunnel, do sw cksum. We can assume
 647                          * the cksum field is in the first segment since the
 648                          * buffers we provided to the host are large enough.
 649                          * In case of SCTP, this will be wrong since it's a CRC
 650                          * but there's nothing we can do.
 651                          */
 652                         uint16_t csum = 0, off;
 653
 654                         rte_raw_cksum_mbuf(m, hdr->csum_start,
 655                                 rte_pktmbuf_pkt_len(m) - hdr->csum_start,
 656                                 &csum);
 657                         if (likely(csum != 0xffff))
 658                                 csum = ~csum;
 659                         off = hdr->csum_offset + hdr->csum_start;
 660                         if (rte_pktmbuf_data_len(m) >= off + 1)
 661                                 *rte_pktmbuf_mtod_offset(m, uint16_t *,
 662                                         off) = csum;
 663                 }
 664         } else if (hdr->flags & VIRTIO_NET_HDR_F_DATA_VALID && l4_supported) {
 665                 m->ol_flags |= PKT_RX_L4_CKSUM_GOOD;
 666         }
 667
 668         /* GSO request, save required information in mbuf */
 669         if (hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) {
 670                 /* Check unsupported modes */
 671                 if ((hdr->gso_type & VIRTIO_NET_HDR_GSO_ECN) ||
 672                     (hdr->gso_size == 0)) {
 673                         return -EINVAL;
 674                 }
 675
 676                 /* Update mss lengthes in mbuf */
 677                 m->tso_segsz = hdr->gso_size;
 678                 switch (hdr->gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
 679                         case VIRTIO_NET_HDR_GSO_TCPV4:
 680                         case VIRTIO_NET_HDR_GSO_TCPV6:
 681                                 m->ol_flags |= PKT_RX_LRO | \
 682                                         PKT_RX_L4_CKSUM_NONE;
 683                                 break;
 684                         default:
 685                                 return -EINVAL;
 686                 }
 687         }
 688
 689         return 0;
 690 }
 691
 692 static inline int
 693 rx_offload_enabled(struct virtio_hw *hw)
 694 {
 695         return vtpci_with_feature(hw, VIRTIO_NET_F_GUEST_CSUM) ||
 696                 vtpci_with_feature(hw, VIRTIO_NET_F_GUEST_TSO4) ||
 697                 vtpci_with_feature(hw, VIRTIO_NET_F_GUEST_TSO6);
 698 }
 699
 700 #define VIRTIO_MBUF_BURST_SZ 64
 701 #define DESC_PER_CACHELINE (RTE_CACHE_LINE_SIZE / sizeof(struct vring_desc))
 702 uint16_t
 703 virtio_recv_pkts(void *rx_queue, struct rte_mbuf **rx_pkts, uint16_t nb_pkts)
 704 {
 705         struct virtnet_rx *rxvq = rx_queue;
 706         struct virtqueue *vq = rxvq->vq;
 707         struct virtio_hw *hw = vq->hw;
 708         struct rte_mbuf *rxm, *new_mbuf;
 709         uint16_t nb_used, num, nb_rx;
 710         uint32_t len[VIRTIO_MBUF_BURST_SZ];
 711         struct rte_mbuf *rcv_pkts[VIRTIO_MBUF_BURST_SZ];
 712         int error;
 713         uint32_t i, nb_enqueued;
 714         uint32_t hdr_size;
 715         int offload;
 716         struct virtio_net_hdr *hdr;
 717
 718         nb_rx = 0;
 719         if (unlikely(hw->started == 0))
 720                 return nb_rx;
 721
 722         nb_used = VIRTQUEUE_NUSED(vq);
 723
 724         virtio_rmb();
 725
 726         num = likely(nb_used <= nb_pkts) ? nb_used : nb_pkts;
 727         if (unlikely(num > VIRTIO_MBUF_BURST_SZ))
 728                 num = VIRTIO_MBUF_BURST_SZ;
 729         if (likely(num > DESC_PER_CACHELINE))
 730                 num = num - ((vq->vq_used_cons_idx + num) % DESC_PER_CACHELINE);
 731
 732         num = virtqueue_dequeue_burst_rx(vq, rcv_pkts, len, num);
 733         PMD_RX_LOG(DEBUG, "used:%d dequeue:%d", nb_used, num);
 734
 735         nb_enqueued = 0;
 736         hdr_size = hw->vtnet_hdr_size;
 737         offload = rx_offload_enabled(hw);
 738
 739         for (i = 0; i < num ; i++) {
 740                 rxm = rcv_pkts[i];
 741
 742                 PMD_RX_LOG(DEBUG, "packet len:%d", len[i]);
 743
 744                 if (unlikely(len[i] < hdr_size + ETHER_HDR_LEN)) {
 745                         PMD_RX_LOG(ERR, "Packet drop");
 746                         nb_enqueued++;
 747                         virtio_discard_rxbuf(vq, rxm);
 748                         rxvq->stats.errors++;
 749                         continue;
 750                 }
 751
 752                 rxm->port = rxvq->port_id;
 753                 rxm->data_off = RTE_PKTMBUF_HEADROOM;
 754                 rxm->ol_flags = 0;
 755                 rxm->vlan_tci = 0;
 756
 757                 rxm->pkt_len = (uint32_t)(len[i] - hdr_size);
 758                 rxm->data_len = (uint16_t)(len[i] - hdr_size);
 759
 760                 hdr = (struct virtio_net_hdr *)((char *)rxm->buf_addr +
 761                         RTE_PKTMBUF_HEADROOM - hdr_size);
 762
 763                 if (hw->vlan_strip)
 764                         rte_vlan_strip(rxm);
 765
 766                 if (offload && virtio_rx_offload(rxm, hdr) < 0) {
 767                         virtio_discard_rxbuf(vq, rxm);
 768                         rxvq->stats.errors++;
 769                         continue;
 770                 }
 771
 772                 VIRTIO_DUMP_PACKET(rxm, rxm->data_len);
 773
 774                 rx_pkts[nb_rx++] = rxm;
 775
 776                 rxvq->stats.bytes += rxm->pkt_len;
 777                 virtio_update_packet_stats(&rxvq->stats, rxm);
 778         }
 779
 780         rxvq->stats.packets += nb_rx;
 781
 782         /* Allocate new mbuf for the used descriptor */
 783         error = ENOSPC;
 784         while (likely(!virtqueue_full(vq))) {
 785                 new_mbuf = rte_mbuf_raw_alloc(rxvq->mpool);
 786                 if (unlikely(new_mbuf == NULL)) {
 787                         struct rte_eth_dev *dev
 788                                 = &rte_eth_devices[rxvq->port_id];
 789                         dev->data->rx_mbuf_alloc_failed++;
 790                         break;
 791                 }
 792                 error = virtqueue_enqueue_recv_refill(vq, new_mbuf);
 793                 if (unlikely(error)) {
 794                         rte_pktmbuf_free(new_mbuf);
 795                         break;
 796                 }
 797                 nb_enqueued++;
 798         }
 799
 800         if (likely(nb_enqueued)) {
 801                 vq_update_avail_idx(vq);
 802
 803                 if (unlikely(virtqueue_kick_prepare(vq))) {
 804                         virtqueue_notify(vq);
 805                         PMD_RX_LOG(DEBUG, "Notified");
 806                 }
 807         }
 808
 809         return nb_rx;
 810 }
 811
 812 uint16_t
 813 virtio_recv_mergeable_pkts(void *rx_queue,
 814                         struct rte_mbuf **rx_pkts,
 815                         uint16_t nb_pkts)
 816 {
 817         struct virtnet_rx *rxvq = rx_queue;
 818         struct virtqueue *vq = rxvq->vq;
 819         struct virtio_hw *hw = vq->hw;
 820         struct rte_mbuf *rxm, *new_mbuf;
 821         uint16_t nb_used, num, nb_rx;
 822         uint32_t len[VIRTIO_MBUF_BURST_SZ];
 823         struct rte_mbuf *rcv_pkts[VIRTIO_MBUF_BURST_SZ];
 824         struct rte_mbuf *prev;
 825         int error;
 826         uint32_t i, nb_enqueued;
 827         uint32_t seg_num;
 828         uint16_t extra_idx;
 829         uint32_t seg_res;
 830         uint32_t hdr_size;
 831         int offload;
 832
 833         nb_rx = 0;
 834         if (unlikely(hw->started == 0))
 835                 return nb_rx;
 836
 837         nb_used = VIRTQUEUE_NUSED(vq);
 838
 839         virtio_rmb();
 840
 841         PMD_RX_LOG(DEBUG, "used:%d", nb_used);
 842
 843         i = 0;
 844         nb_enqueued = 0;
 845         seg_num = 0;
 846         extra_idx = 0;
 847         seg_res = 0;
 848         hdr_size = hw->vtnet_hdr_size;
 849         offload = rx_offload_enabled(hw);
 850
 851         while (i < nb_used) {
 852                 struct virtio_net_hdr_mrg_rxbuf *header;
 853
 854                 if (nb_rx == nb_pkts)
 855                         break;
 856
 857                 num = virtqueue_dequeue_burst_rx(vq, rcv_pkts, len, 1);
 858                 if (num != 1)
 859                         continue;
 860
 861                 i++;
 862
 863                 PMD_RX_LOG(DEBUG, "dequeue:%d", num);
 864                 PMD_RX_LOG(DEBUG, "packet len:%d", len[0]);
 865
 866                 rxm = rcv_pkts[0];
 867
 868                 if (unlikely(len[0] < hdr_size + ETHER_HDR_LEN)) {
 869                         PMD_RX_LOG(ERR, "Packet drop");
 870                         nb_enqueued++;
 871                         virtio_discard_rxbuf(vq, rxm);
 872                         rxvq->stats.errors++;
 873                         continue;
 874                 }
 875
 876                 header = (struct virtio_net_hdr_mrg_rxbuf *)((char *)rxm->buf_addr +
 877                         RTE_PKTMBUF_HEADROOM - hdr_size);
 878                 seg_num = header->num_buffers;
 879
 880                 if (seg_num == 0)
 881                         seg_num = 1;
 882
 883                 rxm->data_off = RTE_PKTMBUF_HEADROOM;
 884                 rxm->nb_segs = seg_num;
 885                 rxm->ol_flags = 0;
 886                 rxm->vlan_tci = 0;
 887                 rxm->pkt_len = (uint32_t)(len[0] - hdr_size);
 888                 rxm->data_len = (uint16_t)(len[0] - hdr_size);
 889
 890                 rxm->port = rxvq->port_id;
 891                 rx_pkts[nb_rx] = rxm;
 892                 prev = rxm;
 893
 894                 if (offload && virtio_rx_offload(rxm, &header->hdr) < 0) {
 895                         virtio_discard_rxbuf(vq, rxm);
 896                         rxvq->stats.errors++;
 897                         continue;
 898                 }
 899
 900                 seg_res = seg_num - 1;
 901
 902                 while (seg_res != 0) {
 903                         /*
 904                          * Get extra segments for current uncompleted packet.
 905                          */
 906                         uint16_t  rcv_cnt =
 907                                 RTE_MIN(seg_res, RTE_DIM(rcv_pkts));
 908                         if (likely(VIRTQUEUE_NUSED(vq) >= rcv_cnt)) {
 909                                 uint32_t rx_num =
 910                                         virtqueue_dequeue_burst_rx(vq,
 911                                         rcv_pkts, len, rcv_cnt);
 912                                 i += rx_num;
 913                                 rcv_cnt = rx_num;
 914                         } else {
 915                                 PMD_RX_LOG(ERR,
 916                                            "No enough segments for packet.");
 917                                 nb_enqueued++;
 918                                 virtio_discard_rxbuf(vq, rxm);
 919                                 rxvq->stats.errors++;
 920                                 break;
 921                         }
 922
 923                         extra_idx = 0;
 924
 925                         while (extra_idx < rcv_cnt) {
 926                                 rxm = rcv_pkts[extra_idx];
 927
 928                                 rxm->data_off = RTE_PKTMBUF_HEADROOM - hdr_size;
 929                                 rxm->pkt_len = (uint32_t)(len[extra_idx]);
 930                                 rxm->data_len = (uint16_t)(len[extra_idx]);
 931
 932                                 if (prev)
 933                                         prev->next = rxm;
 934
 935                                 prev = rxm;
 936                                 rx_pkts[nb_rx]->pkt_len += rxm->pkt_len;
 937                                 extra_idx++;
 938                         };
 939                         seg_res -= rcv_cnt;
 940                 }
 941
 942                 if (hw->vlan_strip)
 943                         rte_vlan_strip(rx_pkts[nb_rx]);
 944
 945                 VIRTIO_DUMP_PACKET(rx_pkts[nb_rx],
 946                         rx_pkts[nb_rx]->data_len);
 947
 948                 rxvq->stats.bytes += rx_pkts[nb_rx]->pkt_len;
 949                 virtio_update_packet_stats(&rxvq->stats, rx_pkts[nb_rx]);
 950                 nb_rx++;
 951         }
 952
 953         rxvq->stats.packets += nb_rx;
 954
 955         /* Allocate new mbuf for the used descriptor */
 956         error = ENOSPC;
 957         while (likely(!virtqueue_full(vq))) {
 958                 new_mbuf = rte_mbuf_raw_alloc(rxvq->mpool);
 959                 if (unlikely(new_mbuf == NULL)) {
 960                         struct rte_eth_dev *dev
 961                                 = &rte_eth_devices[rxvq->port_id];
 962                         dev->data->rx_mbuf_alloc_failed++;
 963                         break;
 964                 }
 965                 error = virtqueue_enqueue_recv_refill(vq, new_mbuf);
 966                 if (unlikely(error)) {
 967                         rte_pktmbuf_free(new_mbuf);
 968                         break;
 969                 }
 970                 nb_enqueued++;
 971         }
 972
 973         if (likely(nb_enqueued)) {
 974                 vq_update_avail_idx(vq);
 975
 976                 if (unlikely(virtqueue_kick_prepare(vq))) {
 977                         virtqueue_notify(vq);
 978                         PMD_RX_LOG(DEBUG, "Notified");
 979                 }
 980         }
 981
 982         return nb_rx;
 983 }
 984
 985 uint16_t
 986 virtio_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts, uint16_t nb_pkts)
 987 {
 988         struct virtnet_tx *txvq = tx_queue;
 989         struct virtqueue *vq = txvq->vq;
 990         struct virtio_hw *hw = vq->hw;
 991         uint16_t hdr_size = hw->vtnet_hdr_size;
 992         uint16_t nb_used, nb_tx = 0;
 993         int error;
 994
 995         if (unlikely(hw->started == 0 && tx_pkts != hw->inject_pkts))
 996                 return nb_tx;
 997
 998         if (unlikely(nb_pkts < 1))
 999                 return nb_pkts;
1000
1001         PMD_TX_LOG(DEBUG, "%d packets to xmit", nb_pkts);
1002         nb_used = VIRTQUEUE_NUSED(vq);
1003
1004         virtio_rmb();
1005         if (likely(nb_used > vq->vq_nentries - vq->vq_free_thresh))
1006                 virtio_xmit_cleanup(vq, nb_used);
1007
1008         for (nb_tx = 0; nb_tx < nb_pkts; nb_tx++) {
1009                 struct rte_mbuf *txm = tx_pkts[nb_tx];
1010                 int can_push = 0, use_indirect = 0, slots, need;
1011
1012                 /* Do VLAN tag insertion */
1013                 if (unlikely(txm->ol_flags & PKT_TX_VLAN_PKT)) {
1014                         error = rte_vlan_insert(&txm);
1015                         if (unlikely(error)) {
1016                                 rte_pktmbuf_free(txm);
1017                                 continue;
1018                         }
1019                 }
1020
1021                 /* optimize ring usage */
1022                 if ((vtpci_with_feature(hw, VIRTIO_F_ANY_LAYOUT) ||
1023                       vtpci_with_feature(hw, VIRTIO_F_VERSION_1)) &&
1024                     rte_mbuf_refcnt_read(txm) == 1 &&
1025                     RTE_MBUF_DIRECT(txm) &&
1026                     txm->nb_segs == 1 &&
1027                     rte_pktmbuf_headroom(txm) >= hdr_size &&
1028                     rte_is_aligned(rte_pktmbuf_mtod(txm, char *),
1029                                    __alignof__(struct virtio_net_hdr_mrg_rxbuf)))
1030                         can_push = 1;
1031                 else if (vtpci_with_feature(hw, VIRTIO_RING_F_INDIRECT_DESC) &&
1032                          txm->nb_segs < VIRTIO_MAX_TX_INDIRECT)
1033                         use_indirect = 1;
1034
1035                 /* How many main ring entries are needed to this Tx?
1036                  * any_layout => number of segments
1037                  * indirect   => 1
1038                  * default    => number of segments + 1
1039                  */
1040                 slots = use_indirect ? 1 : (txm->nb_segs + !can_push);
1041                 need = slots - vq->vq_free_cnt;
1042
1043                 /* Positive value indicates it need free vring descriptors */
1044                 if (unlikely(need > 0)) {
1045                         nb_used = VIRTQUEUE_NUSED(vq);
1046                         virtio_rmb();
1047                         need = RTE_MIN(need, (int)nb_used);
1048
1049                         virtio_xmit_cleanup(vq, need);
1050                         need = slots - vq->vq_free_cnt;
1051                         if (unlikely(need > 0)) {
1052                                 PMD_TX_LOG(ERR,
1053                                            "No free tx descriptors to transmit");
1054                                 break;
1055                         }
1056                 }
1057
1058                 /* Enqueue Packet buffers */
1059                 virtqueue_enqueue_xmit(txvq, txm, slots, use_indirect, can_push);
1060
1061                 txvq->stats.bytes += txm->pkt_len;
1062                 virtio_update_packet_stats(&txvq->stats, txm);
1063         }
1064
1065         txvq->stats.packets += nb_tx;
1066
1067         if (likely(nb_tx)) {
1068                 vq_update_avail_idx(vq);
1069
1070                 if (unlikely(virtqueue_kick_prepare(vq))) {
1071                         virtqueue_notify(vq);
1072                         PMD_TX_LOG(DEBUG, "Notified backend after xmit");
1073                 }
1074         }
1075
1076         return nb_tx;
1077 }