drivers/net/virtio/virtio_rxtx.c

   1 /*-
   2  *   BSD LICENSE
   3  *
   4  *   Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
   5  *   All rights reserved.
   6  *
   7  *   Redistribution and use in source and binary forms, with or without
   8  *   modification, are permitted provided that the following conditions
   9  *   are met:
  10  *
  11  *     * Redistributions of source code must retain the above copyright
  12  *       notice, this list of conditions and the following disclaimer.
  13  *     * Redistributions in binary form must reproduce the above copyright
  14  *       notice, this list of conditions and the following disclaimer in
  15  *       the documentation and/or other materials provided with the
  16  *       distribution.
  17  *     * Neither the name of Intel Corporation nor the names of its
  18  *       contributors may be used to endorse or promote products derived
  19  *       from this software without specific prior written permission.
  20  *
  21  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  22  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  23  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  24  *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  25  *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  26  *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  27  *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  28  *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  29  *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  30  *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  31  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  32  */
  33
  34 #include <stdint.h>
  35 #include <stdio.h>
  36 #include <stdlib.h>
  37 #include <string.h>
  38 #include <errno.h>
  39
  40 #include <rte_cycles.h>
  41 #include <rte_memory.h>
  42 #include <rte_memzone.h>
  43 #include <rte_branch_prediction.h>
  44 #include <rte_mempool.h>
  45 #include <rte_malloc.h>
  46 #include <rte_mbuf.h>
  47 #include <rte_ether.h>
  48 #include <rte_ethdev.h>
  49 #include <rte_prefetch.h>
  50 #include <rte_string_fns.h>
  51 #include <rte_errno.h>
  52 #include <rte_byteorder.h>
  53 #include <rte_cpuflags.h>
  54 #include <rte_net.h>
  55 #include <rte_ip.h>
  56 #include <rte_udp.h>
  57 #include <rte_tcp.h>
  58
  59 #include "virtio_logs.h"
  60 #include "virtio_ethdev.h"
  61 #include "virtio_pci.h"
  62 #include "virtqueue.h"
  63 #include "virtio_rxtx.h"
  64
  65 #ifdef RTE_LIBRTE_VIRTIO_DEBUG_DUMP
  66 #define VIRTIO_DUMP_PACKET(m, len) rte_pktmbuf_dump(stdout, m, len)
  67 #else
  68 #define  VIRTIO_DUMP_PACKET(m, len) do { } while (0)
  69 #endif
  70
  71
  72 #define VIRTIO_SIMPLE_FLAGS ((uint32_t)ETH_TXQ_FLAGS_NOMULTSEGS | \
  73         ETH_TXQ_FLAGS_NOOFFLOADS)
  74
  75 static void
  76 vq_ring_free_chain(struct virtqueue *vq, uint16_t desc_idx)
  77 {
  78         struct vring_desc *dp, *dp_tail;
  79         struct vq_desc_extra *dxp;
  80         uint16_t desc_idx_last = desc_idx;
  81
  82         dp  = &vq->vq_ring.desc[desc_idx];
  83         dxp = &vq->vq_descx[desc_idx];
  84         vq->vq_free_cnt = (uint16_t)(vq->vq_free_cnt + dxp->ndescs);
  85         if ((dp->flags & VRING_DESC_F_INDIRECT) == 0) {
  86                 while (dp->flags & VRING_DESC_F_NEXT) {
  87                         desc_idx_last = dp->next;
  88                         dp = &vq->vq_ring.desc[dp->next];
  89                 }
  90         }
  91         dxp->ndescs = 0;
  92
  93         /*
  94          * We must append the existing free chain, if any, to the end of
  95          * newly freed chain. If the virtqueue was completely used, then
  96          * head would be VQ_RING_DESC_CHAIN_END (ASSERTed above).
  97          */
  98         if (vq->vq_desc_tail_idx == VQ_RING_DESC_CHAIN_END) {
  99                 vq->vq_desc_head_idx = desc_idx;
 100         } else {
 101                 dp_tail = &vq->vq_ring.desc[vq->vq_desc_tail_idx];
 102                 dp_tail->next = desc_idx;
 103         }
 104
 105         vq->vq_desc_tail_idx = desc_idx_last;
 106         dp->next = VQ_RING_DESC_CHAIN_END;
 107 }
 108
 109 static uint16_t
 110 virtqueue_dequeue_burst_rx(struct virtqueue *vq, struct rte_mbuf **rx_pkts,
 111                            uint32_t *len, uint16_t num)
 112 {
 113         struct vring_used_elem *uep;
 114         struct rte_mbuf *cookie;
 115         uint16_t used_idx, desc_idx;
 116         uint16_t i;
 117
 118         /*  Caller does the check */
 119         for (i = 0; i < num ; i++) {
 120                 used_idx = (uint16_t)(vq->vq_used_cons_idx & (vq->vq_nentries - 1));
 121                 uep = &vq->vq_ring.used->ring[used_idx];
 122                 desc_idx = (uint16_t) uep->id;
 123                 len[i] = uep->len;
 124                 cookie = (struct rte_mbuf *)vq->vq_descx[desc_idx].cookie;
 125
 126                 if (unlikely(cookie == NULL)) {
 127                         PMD_DRV_LOG(ERR, "vring descriptor with no mbuf cookie at %u\n",
 128                                 vq->vq_used_cons_idx);
 129                         break;
 130                 }
 131
 132                 rte_prefetch0(cookie);
 133                 rte_packet_prefetch(rte_pktmbuf_mtod(cookie, void *));
 134                 rx_pkts[i]  = cookie;
 135                 vq->vq_used_cons_idx++;
 136                 vq_ring_free_chain(vq, desc_idx);
 137                 vq->vq_descx[desc_idx].cookie = NULL;
 138         }
 139
 140         return i;
 141 }
 142
 143 #ifndef DEFAULT_TX_FREE_THRESH
 144 #define DEFAULT_TX_FREE_THRESH 32
 145 #endif
 146
 147 /* Cleanup from completed transmits. */
 148 static void
 149 virtio_xmit_cleanup(struct virtqueue *vq, uint16_t num)
 150 {
 151         uint16_t i, used_idx, desc_idx;
 152         for (i = 0; i < num; i++) {
 153                 struct vring_used_elem *uep;
 154                 struct vq_desc_extra *dxp;
 155
 156                 used_idx = (uint16_t)(vq->vq_used_cons_idx & (vq->vq_nentries - 1));
 157                 uep = &vq->vq_ring.used->ring[used_idx];
 158
 159                 desc_idx = (uint16_t) uep->id;
 160                 dxp = &vq->vq_descx[desc_idx];
 161                 vq->vq_used_cons_idx++;
 162                 vq_ring_free_chain(vq, desc_idx);
 163
 164                 if (dxp->cookie != NULL) {
 165                         rte_pktmbuf_free(dxp->cookie);
 166                         dxp->cookie = NULL;
 167                 }
 168         }
 169 }
 170
 171
 172 static inline int
 173 virtqueue_enqueue_recv_refill(struct virtqueue *vq, struct rte_mbuf *cookie)
 174 {
 175         struct vq_desc_extra *dxp;
 176         struct virtio_hw *hw = vq->hw;
 177         struct vring_desc *start_dp;
 178         uint16_t needed = 1;
 179         uint16_t head_idx, idx;
 180
 181         if (unlikely(vq->vq_free_cnt == 0))
 182                 return -ENOSPC;
 183         if (unlikely(vq->vq_free_cnt < needed))
 184                 return -EMSGSIZE;
 185
 186         head_idx = vq->vq_desc_head_idx;
 187         if (unlikely(head_idx >= vq->vq_nentries))
 188                 return -EFAULT;
 189
 190         idx = head_idx;
 191         dxp = &vq->vq_descx[idx];
 192         dxp->cookie = (void *)cookie;
 193         dxp->ndescs = needed;
 194
 195         start_dp = vq->vq_ring.desc;
 196         start_dp[idx].addr =
 197                 VIRTIO_MBUF_ADDR(cookie, vq) +
 198                 RTE_PKTMBUF_HEADROOM - hw->vtnet_hdr_size;
 199         start_dp[idx].len =
 200                 cookie->buf_len - RTE_PKTMBUF_HEADROOM + hw->vtnet_hdr_size;
 201         start_dp[idx].flags =  VRING_DESC_F_WRITE;
 202         idx = start_dp[idx].next;
 203         vq->vq_desc_head_idx = idx;
 204         if (vq->vq_desc_head_idx == VQ_RING_DESC_CHAIN_END)
 205                 vq->vq_desc_tail_idx = idx;
 206         vq->vq_free_cnt = (uint16_t)(vq->vq_free_cnt - needed);
 207         vq_update_avail_ring(vq, head_idx);
 208
 209         return 0;
 210 }
 211
 212 /* When doing TSO, the IP length is not included in the pseudo header
 213  * checksum of the packet given to the PMD, but for virtio it is
 214  * expected.
 215  */
 216 static void
 217 virtio_tso_fix_cksum(struct rte_mbuf *m)
 218 {
 219         /* common case: header is not fragmented */
 220         if (likely(rte_pktmbuf_data_len(m) >= m->l2_len + m->l3_len +
 221                         m->l4_len)) {
 222                 struct ipv4_hdr *iph;
 223                 struct ipv6_hdr *ip6h;
 224                 struct tcp_hdr *th;
 225                 uint16_t prev_cksum, new_cksum, ip_len, ip_paylen;
 226                 uint32_t tmp;
 227
 228                 iph = rte_pktmbuf_mtod_offset(m, struct ipv4_hdr *, m->l2_len);
 229                 th = RTE_PTR_ADD(iph, m->l3_len);
 230                 if ((iph->version_ihl >> 4) == 4) {
 231                         iph->hdr_checksum = 0;
 232                         iph->hdr_checksum = rte_ipv4_cksum(iph);
 233                         ip_len = iph->total_length;
 234                         ip_paylen = rte_cpu_to_be_16(rte_be_to_cpu_16(ip_len) -
 235                                 m->l3_len);
 236                 } else {
 237                         ip6h = (struct ipv6_hdr *)iph;
 238                         ip_paylen = ip6h->payload_len;
 239                 }
 240
 241                 /* calculate the new phdr checksum not including ip_paylen */
 242                 prev_cksum = th->cksum;
 243                 tmp = prev_cksum;
 244                 tmp += ip_paylen;
 245                 tmp = (tmp & 0xffff) + (tmp >> 16);
 246                 new_cksum = tmp;
 247
 248                 /* replace it in the packet */
 249                 th->cksum = new_cksum;
 250         }
 251 }
 252
 253 static inline int
 254 tx_offload_enabled(struct virtio_hw *hw)
 255 {
 256         return vtpci_with_feature(hw, VIRTIO_NET_F_CSUM) ||
 257                 vtpci_with_feature(hw, VIRTIO_NET_F_HOST_TSO4) ||
 258                 vtpci_with_feature(hw, VIRTIO_NET_F_HOST_TSO6);
 259 }
 260
 261 /* avoid write operation when necessary, to lessen cache issues */
 262 #define ASSIGN_UNLESS_EQUAL(var, val) do {      \
 263         if ((var) != (val))                     \
 264                 (var) = (val);                  \
 265 } while (0)
 266
 267 static inline void
 268 virtqueue_enqueue_xmit(struct virtnet_tx *txvq, struct rte_mbuf *cookie,
 269                        uint16_t needed, int use_indirect, int can_push)
 270 {
 271         struct virtio_tx_region *txr = txvq->virtio_net_hdr_mz->addr;
 272         struct vq_desc_extra *dxp;
 273         struct virtqueue *vq = txvq->vq;
 274         struct vring_desc *start_dp;
 275         uint16_t seg_num = cookie->nb_segs;
 276         uint16_t head_idx, idx;
 277         uint16_t head_size = vq->hw->vtnet_hdr_size;
 278         struct virtio_net_hdr *hdr;
 279         int offload;
 280
 281         offload = tx_offload_enabled(vq->hw);
 282         head_idx = vq->vq_desc_head_idx;
 283         idx = head_idx;
 284         dxp = &vq->vq_descx[idx];
 285         dxp->cookie = (void *)cookie;
 286         dxp->ndescs = needed;
 287
 288         start_dp = vq->vq_ring.desc;
 289
 290         if (can_push) {
 291                 /* prepend cannot fail, checked by caller */
 292                 hdr = (struct virtio_net_hdr *)
 293                         rte_pktmbuf_prepend(cookie, head_size);
 294                 /* if offload disabled, it is not zeroed below, do it now */
 295                 if (offload == 0) {
 296                         ASSIGN_UNLESS_EQUAL(hdr->csum_start, 0);
 297                         ASSIGN_UNLESS_EQUAL(hdr->csum_offset, 0);
 298                         ASSIGN_UNLESS_EQUAL(hdr->flags, 0);
 299                         ASSIGN_UNLESS_EQUAL(hdr->gso_type, 0);
 300                         ASSIGN_UNLESS_EQUAL(hdr->gso_size, 0);
 301                         ASSIGN_UNLESS_EQUAL(hdr->hdr_len, 0);
 302                 }
 303         } else if (use_indirect) {
 304                 /* setup tx ring slot to point to indirect
 305                  * descriptor list stored in reserved region.
 306                  *
 307                  * the first slot in indirect ring is already preset
 308                  * to point to the header in reserved region
 309                  */
 310                 start_dp[idx].addr  = txvq->virtio_net_hdr_mem +
 311                         RTE_PTR_DIFF(&txr[idx].tx_indir, txr);
 312                 start_dp[idx].len   = (seg_num + 1) * sizeof(struct vring_desc);
 313                 start_dp[idx].flags = VRING_DESC_F_INDIRECT;
 314                 hdr = (struct virtio_net_hdr *)&txr[idx].tx_hdr;
 315
 316                 /* loop below will fill in rest of the indirect elements */
 317                 start_dp = txr[idx].tx_indir;
 318                 idx = 1;
 319         } else {
 320                 /* setup first tx ring slot to point to header
 321                  * stored in reserved region.
 322                  */
 323                 start_dp[idx].addr  = txvq->virtio_net_hdr_mem +
 324                         RTE_PTR_DIFF(&txr[idx].tx_hdr, txr);
 325                 start_dp[idx].len   = vq->hw->vtnet_hdr_size;
 326                 start_dp[idx].flags = VRING_DESC_F_NEXT;
 327                 hdr = (struct virtio_net_hdr *)&txr[idx].tx_hdr;
 328
 329                 idx = start_dp[idx].next;
 330         }
 331
 332         /* Checksum Offload / TSO */
 333         if (offload) {
 334                 if (cookie->ol_flags & PKT_TX_TCP_SEG)
 335                         cookie->ol_flags |= PKT_TX_TCP_CKSUM;
 336
 337                 switch (cookie->ol_flags & PKT_TX_L4_MASK) {
 338                 case PKT_TX_UDP_CKSUM:
 339                         hdr->csum_start = cookie->l2_len + cookie->l3_len;
 340                         hdr->csum_offset = offsetof(struct udp_hdr,
 341                                 dgram_cksum);
 342                         hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
 343                         break;
 344
 345                 case PKT_TX_TCP_CKSUM:
 346                         hdr->csum_start = cookie->l2_len + cookie->l3_len;
 347                         hdr->csum_offset = offsetof(struct tcp_hdr, cksum);
 348                         hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
 349                         break;
 350
 351                 default:
 352                         ASSIGN_UNLESS_EQUAL(hdr->csum_start, 0);
 353                         ASSIGN_UNLESS_EQUAL(hdr->csum_offset, 0);
 354                         ASSIGN_UNLESS_EQUAL(hdr->flags, 0);
 355                         break;
 356                 }
 357
 358                 /* TCP Segmentation Offload */
 359                 if (cookie->ol_flags & PKT_TX_TCP_SEG) {
 360                         virtio_tso_fix_cksum(cookie);
 361                         hdr->gso_type = (cookie->ol_flags & PKT_TX_IPV6) ?
 362                                 VIRTIO_NET_HDR_GSO_TCPV6 :
 363                                 VIRTIO_NET_HDR_GSO_TCPV4;
 364                         hdr->gso_size = cookie->tso_segsz;
 365                         hdr->hdr_len =
 366                                 cookie->l2_len +
 367                                 cookie->l3_len +
 368                                 cookie->l4_len;
 369                 } else {
 370                         ASSIGN_UNLESS_EQUAL(hdr->gso_type, 0);
 371                         ASSIGN_UNLESS_EQUAL(hdr->gso_size, 0);
 372                         ASSIGN_UNLESS_EQUAL(hdr->hdr_len, 0);
 373                 }
 374         }
 375
 376         do {
 377                 start_dp[idx].addr  = VIRTIO_MBUF_DATA_DMA_ADDR(cookie, vq);
 378                 start_dp[idx].len   = cookie->data_len;
 379                 start_dp[idx].flags = cookie->next ? VRING_DESC_F_NEXT : 0;
 380                 idx = start_dp[idx].next;
 381         } while ((cookie = cookie->next) != NULL);
 382
 383         if (use_indirect)
 384                 idx = vq->vq_ring.desc[head_idx].next;
 385
 386         vq->vq_desc_head_idx = idx;
 387         if (vq->vq_desc_head_idx == VQ_RING_DESC_CHAIN_END)
 388                 vq->vq_desc_tail_idx = idx;
 389         vq->vq_free_cnt = (uint16_t)(vq->vq_free_cnt - needed);
 390         vq_update_avail_ring(vq, head_idx);
 391 }
 392
 393 void
 394 virtio_dev_cq_start(struct rte_eth_dev *dev)
 395 {
 396         struct virtio_hw *hw = dev->data->dev_private;
 397
 398         if (hw->cvq && hw->cvq->vq) {
 399                 VIRTQUEUE_DUMP((struct virtqueue *)hw->cvq->vq);
 400         }
 401 }
 402
 403 int
 404 virtio_dev_rx_queue_setup(struct rte_eth_dev *dev,
 405                         uint16_t queue_idx,
 406                         uint16_t nb_desc,
 407                         unsigned int socket_id __rte_unused,
 408                         __rte_unused const struct rte_eth_rxconf *rx_conf,
 409                         struct rte_mempool *mp)
 410 {
 411         uint16_t vtpci_queue_idx = 2 * queue_idx + VTNET_SQ_RQ_QUEUE_IDX;
 412         struct virtio_hw *hw = dev->data->dev_private;
 413         struct virtqueue *vq = hw->vqs[vtpci_queue_idx];
 414         struct virtnet_rx *rxvq;
 415         int error, nbufs;
 416         struct rte_mbuf *m;
 417         uint16_t desc_idx;
 418
 419         PMD_INIT_FUNC_TRACE();
 420
 421         if (nb_desc == 0 || nb_desc > vq->vq_nentries)
 422                 nb_desc = vq->vq_nentries;
 423         vq->vq_free_cnt = RTE_MIN(vq->vq_free_cnt, nb_desc);
 424
 425         rxvq = &vq->rxq;
 426         rxvq->queue_id = queue_idx;
 427         rxvq->mpool = mp;
 428         if (rxvq->mpool == NULL) {
 429                 rte_exit(EXIT_FAILURE,
 430                         "Cannot allocate mbufs for rx virtqueue");
 431         }
 432         dev->data->rx_queues[queue_idx] = rxvq;
 433
 434
 435         /* Allocate blank mbufs for the each rx descriptor */
 436         nbufs = 0;
 437         error = ENOSPC;
 438
 439         if (hw->use_simple_rxtx) {
 440                 for (desc_idx = 0; desc_idx < vq->vq_nentries;
 441                      desc_idx++) {
 442                         vq->vq_ring.avail->ring[desc_idx] = desc_idx;
 443                         vq->vq_ring.desc[desc_idx].flags =
 444                                 VRING_DESC_F_WRITE;
 445                 }
 446         }
 447
 448         memset(&rxvq->fake_mbuf, 0, sizeof(rxvq->fake_mbuf));
 449         for (desc_idx = 0; desc_idx < RTE_PMD_VIRTIO_RX_MAX_BURST;
 450              desc_idx++) {
 451                 vq->sw_ring[vq->vq_nentries + desc_idx] =
 452                         &rxvq->fake_mbuf;
 453         }
 454
 455         while (!virtqueue_full(vq)) {
 456                 m = rte_mbuf_raw_alloc(rxvq->mpool);
 457                 if (m == NULL)
 458                         break;
 459
 460                 /* Enqueue allocated buffers */
 461                 if (hw->use_simple_rxtx)
 462                         error = virtqueue_enqueue_recv_refill_simple(vq, m);
 463                 else
 464                         error = virtqueue_enqueue_recv_refill(vq, m);
 465
 466                 if (error) {
 467                         rte_pktmbuf_free(m);
 468                         break;
 469                 }
 470                 nbufs++;
 471         }
 472
 473         vq_update_avail_idx(vq);
 474
 475         PMD_INIT_LOG(DEBUG, "Allocated %d bufs", nbufs);
 476
 477         virtio_rxq_vec_setup(rxvq);
 478
 479         VIRTQUEUE_DUMP(vq);
 480
 481         return 0;
 482 }
 483
 484 static void
 485 virtio_update_rxtx_handler(struct rte_eth_dev *dev,
 486                            const struct rte_eth_txconf *tx_conf)
 487 {
 488         uint8_t use_simple_rxtx = 0;
 489         struct virtio_hw *hw = dev->data->dev_private;
 490
 491 #if defined RTE_ARCH_X86
 492         if (rte_cpu_get_flag_enabled(RTE_CPUFLAG_SSE3))
 493                 use_simple_rxtx = 1;
 494 #elif defined RTE_ARCH_ARM64 || defined CONFIG_RTE_ARCH_ARM
 495         if (rte_cpu_get_flag_enabled(RTE_CPUFLAG_NEON))
 496                 use_simple_rxtx = 1;
 497 #endif
 498         /* Use simple rx/tx func if single segment and no offloads */
 499         if (use_simple_rxtx &&
 500             (tx_conf->txq_flags & VIRTIO_SIMPLE_FLAGS) == VIRTIO_SIMPLE_FLAGS &&
 501             !vtpci_with_feature(hw, VIRTIO_NET_F_MRG_RXBUF)) {
 502                 PMD_INIT_LOG(INFO, "Using simple rx/tx path");
 503                 dev->tx_pkt_burst = virtio_xmit_pkts_simple;
 504                 dev->rx_pkt_burst = virtio_recv_pkts_vec;
 505                 hw->use_simple_rxtx = use_simple_rxtx;
 506         }
 507 }
 508
 509 /*
 510  * struct rte_eth_dev *dev: Used to update dev
 511  * uint16_t nb_desc: Defaults to values read from config space
 512  * unsigned int socket_id: Used to allocate memzone
 513  * const struct rte_eth_txconf *tx_conf: Used to setup tx engine
 514  * uint16_t queue_idx: Just used as an index in dev txq list
 515  */
 516 int
 517 virtio_dev_tx_queue_setup(struct rte_eth_dev *dev,
 518                         uint16_t queue_idx,
 519                         uint16_t nb_desc,
 520                         unsigned int socket_id __rte_unused,
 521                         const struct rte_eth_txconf *tx_conf)
 522 {
 523         uint8_t vtpci_queue_idx = 2 * queue_idx + VTNET_SQ_TQ_QUEUE_IDX;
 524         struct virtio_hw *hw = dev->data->dev_private;
 525         struct virtqueue *vq = hw->vqs[vtpci_queue_idx];
 526         struct virtnet_tx *txvq;
 527         uint16_t tx_free_thresh;
 528         uint16_t desc_idx;
 529
 530         PMD_INIT_FUNC_TRACE();
 531
 532         virtio_update_rxtx_handler(dev, tx_conf);
 533
 534         if (nb_desc == 0 || nb_desc > vq->vq_nentries)
 535                 nb_desc = vq->vq_nentries;
 536         vq->vq_free_cnt = RTE_MIN(vq->vq_free_cnt, nb_desc);
 537
 538         txvq = &vq->txq;
 539         txvq->queue_id = queue_idx;
 540
 541         tx_free_thresh = tx_conf->tx_free_thresh;
 542         if (tx_free_thresh == 0)
 543                 tx_free_thresh =
 544                         RTE_MIN(vq->vq_nentries / 4, DEFAULT_TX_FREE_THRESH);
 545
 546         if (tx_free_thresh >= (vq->vq_nentries - 3)) {
 547                 RTE_LOG(ERR, PMD, "tx_free_thresh must be less than the "
 548                         "number of TX entries minus 3 (%u)."
 549                         " (tx_free_thresh=%u port=%u queue=%u)\n",
 550                         vq->vq_nentries - 3,
 551                         tx_free_thresh, dev->data->port_id, queue_idx);
 552                 return -EINVAL;
 553         }
 554
 555         vq->vq_free_thresh = tx_free_thresh;
 556
 557         if (hw->use_simple_rxtx) {
 558                 uint16_t mid_idx  = vq->vq_nentries >> 1;
 559
 560                 for (desc_idx = 0; desc_idx < mid_idx; desc_idx++) {
 561                         vq->vq_ring.avail->ring[desc_idx] =
 562                                 desc_idx + mid_idx;
 563                         vq->vq_ring.desc[desc_idx + mid_idx].next =
 564                                 desc_idx;
 565                         vq->vq_ring.desc[desc_idx + mid_idx].addr =
 566                                 txvq->virtio_net_hdr_mem +
 567                                 offsetof(struct virtio_tx_region, tx_hdr);
 568                         vq->vq_ring.desc[desc_idx + mid_idx].len =
 569                                 vq->hw->vtnet_hdr_size;
 570                         vq->vq_ring.desc[desc_idx + mid_idx].flags =
 571                                 VRING_DESC_F_NEXT;
 572                         vq->vq_ring.desc[desc_idx].flags = 0;
 573                 }
 574                 for (desc_idx = mid_idx; desc_idx < vq->vq_nentries;
 575                      desc_idx++)
 576                         vq->vq_ring.avail->ring[desc_idx] = desc_idx;
 577         }
 578
 579         VIRTQUEUE_DUMP(vq);
 580
 581         dev->data->tx_queues[queue_idx] = txvq;
 582         return 0;
 583 }
 584
 585 static void
 586 virtio_discard_rxbuf(struct virtqueue *vq, struct rte_mbuf *m)
 587 {
 588         int error;
 589         /*
 590          * Requeue the discarded mbuf. This should always be
 591          * successful since it was just dequeued.
 592          */
 593         error = virtqueue_enqueue_recv_refill(vq, m);
 594         if (unlikely(error)) {
 595                 RTE_LOG(ERR, PMD, "cannot requeue discarded mbuf");
 596                 rte_pktmbuf_free(m);
 597         }
 598 }
 599
 600 static void
 601 virtio_update_packet_stats(struct virtnet_stats *stats, struct rte_mbuf *mbuf)
 602 {
 603         uint32_t s = mbuf->pkt_len;
 604         struct ether_addr *ea;
 605
 606         if (s == 64) {
 607                 stats->size_bins[1]++;
 608         } else if (s > 64 && s < 1024) {
 609                 uint32_t bin;
 610
 611                 /* count zeros, and offset into correct bin */
 612                 bin = (sizeof(s) * 8) - __builtin_clz(s) - 5;
 613                 stats->size_bins[bin]++;
 614         } else {
 615                 if (s < 64)
 616                         stats->size_bins[0]++;
 617                 else if (s < 1519)
 618                         stats->size_bins[6]++;
 619                 else if (s >= 1519)
 620                         stats->size_bins[7]++;
 621         }
 622
 623         ea = rte_pktmbuf_mtod(mbuf, struct ether_addr *);
 624         if (is_multicast_ether_addr(ea)) {
 625                 if (is_broadcast_ether_addr(ea))
 626                         stats->broadcast++;
 627                 else
 628                         stats->multicast++;
 629         }
 630 }
 631
 632 /* Optionally fill offload information in structure */
 633 static int
 634 virtio_rx_offload(struct rte_mbuf *m, struct virtio_net_hdr *hdr)
 635 {
 636         struct rte_net_hdr_lens hdr_lens;
 637         uint32_t hdrlen, ptype;
 638         int l4_supported = 0;
 639
 640         /* nothing to do */
 641         if (hdr->flags == 0 && hdr->gso_type == VIRTIO_NET_HDR_GSO_NONE)
 642                 return 0;
 643
 644         m->ol_flags |= PKT_RX_IP_CKSUM_UNKNOWN;
 645
 646         ptype = rte_net_get_ptype(m, &hdr_lens, RTE_PTYPE_ALL_MASK);
 647         m->packet_type = ptype;
 648         if ((ptype & RTE_PTYPE_L4_MASK) == RTE_PTYPE_L4_TCP ||
 649             (ptype & RTE_PTYPE_L4_MASK) == RTE_PTYPE_L4_UDP ||
 650             (ptype & RTE_PTYPE_L4_MASK) == RTE_PTYPE_L4_SCTP)
 651                 l4_supported = 1;
 652
 653         if (hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
 654                 hdrlen = hdr_lens.l2_len + hdr_lens.l3_len + hdr_lens.l4_len;
 655                 if (hdr->csum_start <= hdrlen && l4_supported) {
 656                         m->ol_flags |= PKT_RX_L4_CKSUM_NONE;
 657                 } else {
 658                         /* Unknown proto or tunnel, do sw cksum. We can assume
 659                          * the cksum field is in the first segment since the
 660                          * buffers we provided to the host are large enough.
 661                          * In case of SCTP, this will be wrong since it's a CRC
 662                          * but there's nothing we can do.
 663                          */
 664                         uint16_t csum, off;
 665
 666                         rte_raw_cksum_mbuf(m, hdr->csum_start,
 667                                 rte_pktmbuf_pkt_len(m) - hdr->csum_start,
 668                                 &csum);
 669                         if (likely(csum != 0xffff))
 670                                 csum = ~csum;
 671                         off = hdr->csum_offset + hdr->csum_start;
 672                         if (rte_pktmbuf_data_len(m) >= off + 1)
 673                                 *rte_pktmbuf_mtod_offset(m, uint16_t *,
 674                                         off) = csum;
 675                 }
 676         } else if (hdr->flags & VIRTIO_NET_HDR_F_DATA_VALID && l4_supported) {
 677                 m->ol_flags |= PKT_RX_L4_CKSUM_GOOD;
 678         }
 679
 680         /* GSO request, save required information in mbuf */
 681         if (hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) {
 682                 /* Check unsupported modes */
 683                 if ((hdr->gso_type & VIRTIO_NET_HDR_GSO_ECN) ||
 684                     (hdr->gso_size == 0)) {
 685                         return -EINVAL;
 686                 }
 687
 688                 /* Update mss lengthes in mbuf */
 689                 m->tso_segsz = hdr->gso_size;
 690                 switch (hdr->gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
 691                         case VIRTIO_NET_HDR_GSO_TCPV4:
 692                         case VIRTIO_NET_HDR_GSO_TCPV6:
 693                                 m->ol_flags |= PKT_RX_LRO | \
 694                                         PKT_RX_L4_CKSUM_NONE;
 695                                 break;
 696                         default:
 697                                 return -EINVAL;
 698                 }
 699         }
 700
 701         return 0;
 702 }
 703
 704 static inline int
 705 rx_offload_enabled(struct virtio_hw *hw)
 706 {
 707         return vtpci_with_feature(hw, VIRTIO_NET_F_GUEST_CSUM) ||
 708                 vtpci_with_feature(hw, VIRTIO_NET_F_GUEST_TSO4) ||
 709                 vtpci_with_feature(hw, VIRTIO_NET_F_GUEST_TSO6);
 710 }
 711
 712 #define VIRTIO_MBUF_BURST_SZ 64
 713 #define DESC_PER_CACHELINE (RTE_CACHE_LINE_SIZE / sizeof(struct vring_desc))
 714 uint16_t
 715 virtio_recv_pkts(void *rx_queue, struct rte_mbuf **rx_pkts, uint16_t nb_pkts)
 716 {
 717         struct virtnet_rx *rxvq = rx_queue;
 718         struct virtqueue *vq = rxvq->vq;
 719         struct virtio_hw *hw;
 720         struct rte_mbuf *rxm, *new_mbuf;
 721         uint16_t nb_used, num, nb_rx;
 722         uint32_t len[VIRTIO_MBUF_BURST_SZ];
 723         struct rte_mbuf *rcv_pkts[VIRTIO_MBUF_BURST_SZ];
 724         int error;
 725         uint32_t i, nb_enqueued;
 726         uint32_t hdr_size;
 727         int offload;
 728         struct virtio_net_hdr *hdr;
 729
 730         nb_used = VIRTQUEUE_NUSED(vq);
 731
 732         virtio_rmb();
 733
 734         num = (uint16_t)(likely(nb_used <= nb_pkts) ? nb_used : nb_pkts);
 735         num = (uint16_t)(likely(num <= VIRTIO_MBUF_BURST_SZ) ? num : VIRTIO_MBUF_BURST_SZ);
 736         if (likely(num > DESC_PER_CACHELINE))
 737                 num = num - ((vq->vq_used_cons_idx + num) % DESC_PER_CACHELINE);
 738
 739         num = virtqueue_dequeue_burst_rx(vq, rcv_pkts, len, num);
 740         PMD_RX_LOG(DEBUG, "used:%d dequeue:%d", nb_used, num);
 741
 742         hw = vq->hw;
 743         nb_rx = 0;
 744         nb_enqueued = 0;
 745         hdr_size = hw->vtnet_hdr_size;
 746         offload = rx_offload_enabled(hw);
 747
 748         for (i = 0; i < num ; i++) {
 749                 rxm = rcv_pkts[i];
 750
 751                 PMD_RX_LOG(DEBUG, "packet len:%d", len[i]);
 752
 753                 if (unlikely(len[i] < hdr_size + ETHER_HDR_LEN)) {
 754                         PMD_RX_LOG(ERR, "Packet drop");
 755                         nb_enqueued++;
 756                         virtio_discard_rxbuf(vq, rxm);
 757                         rxvq->stats.errors++;
 758                         continue;
 759                 }
 760
 761                 rxm->port = rxvq->port_id;
 762                 rxm->data_off = RTE_PKTMBUF_HEADROOM;
 763                 rxm->ol_flags = 0;
 764                 rxm->vlan_tci = 0;
 765
 766                 rxm->nb_segs = 1;
 767                 rxm->next = NULL;
 768                 rxm->pkt_len = (uint32_t)(len[i] - hdr_size);
 769                 rxm->data_len = (uint16_t)(len[i] - hdr_size);
 770
 771                 hdr = (struct virtio_net_hdr *)((char *)rxm->buf_addr +
 772                         RTE_PKTMBUF_HEADROOM - hdr_size);
 773
 774                 if (hw->vlan_strip)
 775                         rte_vlan_strip(rxm);
 776
 777                 if (offload && virtio_rx_offload(rxm, hdr) < 0) {
 778                         virtio_discard_rxbuf(vq, rxm);
 779                         rxvq->stats.errors++;
 780                         continue;
 781                 }
 782
 783                 VIRTIO_DUMP_PACKET(rxm, rxm->data_len);
 784
 785                 rx_pkts[nb_rx++] = rxm;
 786
 787                 rxvq->stats.bytes += rx_pkts[nb_rx - 1]->pkt_len;
 788                 virtio_update_packet_stats(&rxvq->stats, rxm);
 789         }
 790
 791         rxvq->stats.packets += nb_rx;
 792
 793         /* Allocate new mbuf for the used descriptor */
 794         error = ENOSPC;
 795         while (likely(!virtqueue_full(vq))) {
 796                 new_mbuf = rte_mbuf_raw_alloc(rxvq->mpool);
 797                 if (unlikely(new_mbuf == NULL)) {
 798                         struct rte_eth_dev *dev
 799                                 = &rte_eth_devices[rxvq->port_id];
 800                         dev->data->rx_mbuf_alloc_failed++;
 801                         break;
 802                 }
 803                 error = virtqueue_enqueue_recv_refill(vq, new_mbuf);
 804                 if (unlikely(error)) {
 805                         rte_pktmbuf_free(new_mbuf);
 806                         break;
 807                 }
 808                 nb_enqueued++;
 809         }
 810
 811         if (likely(nb_enqueued)) {
 812                 vq_update_avail_idx(vq);
 813
 814                 if (unlikely(virtqueue_kick_prepare(vq))) {
 815                         virtqueue_notify(vq);
 816                         PMD_RX_LOG(DEBUG, "Notified");
 817                 }
 818         }
 819
 820         return nb_rx;
 821 }
 822
 823 uint16_t
 824 virtio_recv_mergeable_pkts(void *rx_queue,
 825                         struct rte_mbuf **rx_pkts,
 826                         uint16_t nb_pkts)
 827 {
 828         struct virtnet_rx *rxvq = rx_queue;
 829         struct virtqueue *vq = rxvq->vq;
 830         struct virtio_hw *hw;
 831         struct rte_mbuf *rxm, *new_mbuf;
 832         uint16_t nb_used, num, nb_rx;
 833         uint32_t len[VIRTIO_MBUF_BURST_SZ];
 834         struct rte_mbuf *rcv_pkts[VIRTIO_MBUF_BURST_SZ];
 835         struct rte_mbuf *prev;
 836         int error;
 837         uint32_t i, nb_enqueued;
 838         uint32_t seg_num;
 839         uint16_t extra_idx;
 840         uint32_t seg_res;
 841         uint32_t hdr_size;
 842         int offload;
 843
 844         nb_used = VIRTQUEUE_NUSED(vq);
 845
 846         virtio_rmb();
 847
 848         PMD_RX_LOG(DEBUG, "used:%d", nb_used);
 849
 850         hw = vq->hw;
 851         nb_rx = 0;
 852         i = 0;
 853         nb_enqueued = 0;
 854         seg_num = 0;
 855         extra_idx = 0;
 856         seg_res = 0;
 857         hdr_size = hw->vtnet_hdr_size;
 858         offload = rx_offload_enabled(hw);
 859
 860         while (i < nb_used) {
 861                 struct virtio_net_hdr_mrg_rxbuf *header;
 862
 863                 if (nb_rx == nb_pkts)
 864                         break;
 865
 866                 num = virtqueue_dequeue_burst_rx(vq, rcv_pkts, len, 1);
 867                 if (num != 1)
 868                         continue;
 869
 870                 i++;
 871
 872                 PMD_RX_LOG(DEBUG, "dequeue:%d", num);
 873                 PMD_RX_LOG(DEBUG, "packet len:%d", len[0]);
 874
 875                 rxm = rcv_pkts[0];
 876
 877                 if (unlikely(len[0] < hdr_size + ETHER_HDR_LEN)) {
 878                         PMD_RX_LOG(ERR, "Packet drop");
 879                         nb_enqueued++;
 880                         virtio_discard_rxbuf(vq, rxm);
 881                         rxvq->stats.errors++;
 882                         continue;
 883                 }
 884
 885                 header = (struct virtio_net_hdr_mrg_rxbuf *)((char *)rxm->buf_addr +
 886                         RTE_PKTMBUF_HEADROOM - hdr_size);
 887                 seg_num = header->num_buffers;
 888
 889                 if (seg_num == 0)
 890                         seg_num = 1;
 891
 892                 rxm->data_off = RTE_PKTMBUF_HEADROOM;
 893                 rxm->nb_segs = seg_num;
 894                 rxm->next = NULL;
 895                 rxm->ol_flags = 0;
 896                 rxm->vlan_tci = 0;
 897                 rxm->pkt_len = (uint32_t)(len[0] - hdr_size);
 898                 rxm->data_len = (uint16_t)(len[0] - hdr_size);
 899
 900                 rxm->port = rxvq->port_id;
 901                 rx_pkts[nb_rx] = rxm;
 902                 prev = rxm;
 903
 904                 if (offload && virtio_rx_offload(rxm, &header->hdr) < 0) {
 905                         virtio_discard_rxbuf(vq, rxm);
 906                         rxvq->stats.errors++;
 907                         continue;
 908                 }
 909
 910                 seg_res = seg_num - 1;
 911
 912                 while (seg_res != 0) {
 913                         /*
 914                          * Get extra segments for current uncompleted packet.
 915                          */
 916                         uint16_t  rcv_cnt =
 917                                 RTE_MIN(seg_res, RTE_DIM(rcv_pkts));
 918                         if (likely(VIRTQUEUE_NUSED(vq) >= rcv_cnt)) {
 919                                 uint32_t rx_num =
 920                                         virtqueue_dequeue_burst_rx(vq,
 921                                         rcv_pkts, len, rcv_cnt);
 922                                 i += rx_num;
 923                                 rcv_cnt = rx_num;
 924                         } else {
 925                                 PMD_RX_LOG(ERR,
 926                                            "No enough segments for packet.");
 927                                 nb_enqueued++;
 928                                 virtio_discard_rxbuf(vq, rxm);
 929                                 rxvq->stats.errors++;
 930                                 break;
 931                         }
 932
 933                         extra_idx = 0;
 934
 935                         while (extra_idx < rcv_cnt) {
 936                                 rxm = rcv_pkts[extra_idx];
 937
 938                                 rxm->data_off = RTE_PKTMBUF_HEADROOM - hdr_size;
 939                                 rxm->next = NULL;
 940                                 rxm->pkt_len = (uint32_t)(len[extra_idx]);
 941                                 rxm->data_len = (uint16_t)(len[extra_idx]);
 942
 943                                 if (prev)
 944                                         prev->next = rxm;
 945
 946                                 prev = rxm;
 947                                 rx_pkts[nb_rx]->pkt_len += rxm->pkt_len;
 948                                 extra_idx++;
 949                         };
 950                         seg_res -= rcv_cnt;
 951                 }
 952
 953                 if (hw->vlan_strip)
 954                         rte_vlan_strip(rx_pkts[nb_rx]);
 955
 956                 VIRTIO_DUMP_PACKET(rx_pkts[nb_rx],
 957                         rx_pkts[nb_rx]->data_len);
 958
 959                 rxvq->stats.bytes += rx_pkts[nb_rx]->pkt_len;
 960                 virtio_update_packet_stats(&rxvq->stats, rx_pkts[nb_rx]);
 961                 nb_rx++;
 962         }
 963
 964         rxvq->stats.packets += nb_rx;
 965
 966         /* Allocate new mbuf for the used descriptor */
 967         error = ENOSPC;
 968         while (likely(!virtqueue_full(vq))) {
 969                 new_mbuf = rte_mbuf_raw_alloc(rxvq->mpool);
 970                 if (unlikely(new_mbuf == NULL)) {
 971                         struct rte_eth_dev *dev
 972                                 = &rte_eth_devices[rxvq->port_id];
 973                         dev->data->rx_mbuf_alloc_failed++;
 974                         break;
 975                 }
 976                 error = virtqueue_enqueue_recv_refill(vq, new_mbuf);
 977                 if (unlikely(error)) {
 978                         rte_pktmbuf_free(new_mbuf);
 979                         break;
 980                 }
 981                 nb_enqueued++;
 982         }
 983
 984         if (likely(nb_enqueued)) {
 985                 vq_update_avail_idx(vq);
 986
 987                 if (unlikely(virtqueue_kick_prepare(vq))) {
 988                         virtqueue_notify(vq);
 989                         PMD_RX_LOG(DEBUG, "Notified");
 990                 }
 991         }
 992
 993         return nb_rx;
 994 }
 995
 996 uint16_t
 997 virtio_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts, uint16_t nb_pkts)
 998 {
 999         struct virtnet_tx *txvq = tx_queue;
1000         struct virtqueue *vq = txvq->vq;
1001         struct virtio_hw *hw = vq->hw;
1002         uint16_t hdr_size = hw->vtnet_hdr_size;
1003         uint16_t nb_used, nb_tx;
1004         int error;
1005
1006         if (unlikely(nb_pkts < 1))
1007                 return nb_pkts;
1008
1009         PMD_TX_LOG(DEBUG, "%d packets to xmit", nb_pkts);
1010         nb_used = VIRTQUEUE_NUSED(vq);
1011
1012         virtio_rmb();
1013         if (likely(nb_used > vq->vq_nentries - vq->vq_free_thresh))
1014                 virtio_xmit_cleanup(vq, nb_used);
1015
1016         for (nb_tx = 0; nb_tx < nb_pkts; nb_tx++) {
1017                 struct rte_mbuf *txm = tx_pkts[nb_tx];
1018                 int can_push = 0, use_indirect = 0, slots, need;
1019
1020                 /* Do VLAN tag insertion */
1021                 if (unlikely(txm->ol_flags & PKT_TX_VLAN_PKT)) {
1022                         error = rte_vlan_insert(&txm);
1023                         if (unlikely(error)) {
1024                                 rte_pktmbuf_free(txm);
1025                                 continue;
1026                         }
1027                 }
1028
1029                 /* optimize ring usage */
1030                 if (vtpci_with_feature(hw, VIRTIO_F_ANY_LAYOUT) &&
1031                     rte_mbuf_refcnt_read(txm) == 1 &&
1032                     RTE_MBUF_DIRECT(txm) &&
1033                     txm->nb_segs == 1 &&
1034                     rte_pktmbuf_headroom(txm) >= hdr_size &&
1035                     rte_is_aligned(rte_pktmbuf_mtod(txm, char *),
1036                                    __alignof__(struct virtio_net_hdr_mrg_rxbuf)))
1037                         can_push = 1;
1038                 else if (vtpci_with_feature(hw, VIRTIO_RING_F_INDIRECT_DESC) &&
1039                          txm->nb_segs < VIRTIO_MAX_TX_INDIRECT)
1040                         use_indirect = 1;
1041
1042                 /* How many main ring entries are needed to this Tx?
1043                  * any_layout => number of segments
1044                  * indirect   => 1
1045                  * default    => number of segments + 1
1046                  */
1047                 slots = use_indirect ? 1 : (txm->nb_segs + !can_push);
1048                 need = slots - vq->vq_free_cnt;
1049
1050                 /* Positive value indicates it need free vring descriptors */
1051                 if (unlikely(need > 0)) {
1052                         nb_used = VIRTQUEUE_NUSED(vq);
1053                         virtio_rmb();
1054                         need = RTE_MIN(need, (int)nb_used);
1055
1056                         virtio_xmit_cleanup(vq, need);
1057                         need = slots - vq->vq_free_cnt;
1058                         if (unlikely(need > 0)) {
1059                                 PMD_TX_LOG(ERR,
1060                                            "No free tx descriptors to transmit");
1061                                 break;
1062                         }
1063                 }
1064
1065                 /* Enqueue Packet buffers */
1066                 virtqueue_enqueue_xmit(txvq, txm, slots, use_indirect, can_push);
1067
1068                 txvq->stats.bytes += txm->pkt_len;
1069                 virtio_update_packet_stats(&txvq->stats, txm);
1070         }
1071
1072         txvq->stats.packets += nb_tx;
1073
1074         if (likely(nb_tx)) {
1075                 vq_update_avail_idx(vq);
1076
1077                 if (unlikely(virtqueue_kick_prepare(vq))) {
1078                         virtqueue_notify(vq);
1079                         PMD_TX_LOG(DEBUG, "Notified backend after xmit");
1080                 }
1081         }
1082
1083         return nb_tx;
1084 }