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
  54 #include "virtio_logs.h"
  55 #include "virtio_ethdev.h"
  56 #include "virtqueue.h"
  57
  58 #ifdef RTE_LIBRTE_VIRTIO_DEBUG_DUMP
  59 #define VIRTIO_DUMP_PACKET(m, len) rte_pktmbuf_dump(stdout, m, len)
  60 #else
  61 #define  VIRTIO_DUMP_PACKET(m, len) do { } while (0)
  62 #endif
  63
  64 static void
  65 vq_ring_free_chain(struct virtqueue *vq, uint16_t desc_idx)
  66 {
  67         struct vring_desc *dp, *dp_tail;
  68         struct vq_desc_extra *dxp;
  69         uint16_t desc_idx_last = desc_idx;
  70
  71         dp  = &vq->vq_ring.desc[desc_idx];
  72         dxp = &vq->vq_descx[desc_idx];
  73         vq->vq_free_cnt = (uint16_t)(vq->vq_free_cnt + dxp->ndescs);
  74         if ((dp->flags & VRING_DESC_F_INDIRECT) == 0) {
  75                 while (dp->flags & VRING_DESC_F_NEXT) {
  76                         desc_idx_last = dp->next;
  77                         dp = &vq->vq_ring.desc[dp->next];
  78                 }
  79         }
  80         dxp->ndescs = 0;
  81
  82         /*
  83          * We must append the existing free chain, if any, to the end of
  84          * newly freed chain. If the virtqueue was completely used, then
  85          * head would be VQ_RING_DESC_CHAIN_END (ASSERTed above).
  86          */
  87         if (vq->vq_desc_tail_idx == VQ_RING_DESC_CHAIN_END) {
  88                 vq->vq_desc_head_idx = desc_idx;
  89         } else {
  90                 dp_tail = &vq->vq_ring.desc[vq->vq_desc_tail_idx];
  91                 dp_tail->next = desc_idx;
  92         }
  93
  94         vq->vq_desc_tail_idx = desc_idx_last;
  95         dp->next = VQ_RING_DESC_CHAIN_END;
  96 }
  97
  98 static uint16_t
  99 virtqueue_dequeue_burst_rx(struct virtqueue *vq, struct rte_mbuf **rx_pkts,
 100                            uint32_t *len, uint16_t num)
 101 {
 102         struct vring_used_elem *uep;
 103         struct rte_mbuf *cookie;
 104         uint16_t used_idx, desc_idx;
 105         uint16_t i;
 106
 107         /*  Caller does the check */
 108         for (i = 0; i < num ; i++) {
 109                 used_idx = (uint16_t)(vq->vq_used_cons_idx & (vq->vq_nentries - 1));
 110                 uep = &vq->vq_ring.used->ring[used_idx];
 111                 desc_idx = (uint16_t) uep->id;
 112                 len[i] = uep->len;
 113                 cookie = (struct rte_mbuf *)vq->vq_descx[desc_idx].cookie;
 114
 115                 if (unlikely(cookie == NULL)) {
 116                         PMD_DRV_LOG(ERR, "vring descriptor with no mbuf cookie at %u\n",
 117                                 vq->vq_used_cons_idx);
 118                         break;
 119                 }
 120
 121                 rte_prefetch0(cookie);
 122                 rte_packet_prefetch(rte_pktmbuf_mtod(cookie, void *));
 123                 rx_pkts[i]  = cookie;
 124                 vq->vq_used_cons_idx++;
 125                 vq_ring_free_chain(vq, desc_idx);
 126                 vq->vq_descx[desc_idx].cookie = NULL;
 127         }
 128
 129         return i;
 130 }
 131
 132 #ifndef DEFAULT_TX_FREE_THRESH
 133 #define DEFAULT_TX_FREE_THRESH 32
 134 #endif
 135
 136 /* Cleanup from completed transmits. */
 137 static void
 138 virtio_xmit_cleanup(struct virtqueue *vq, uint16_t num)
 139 {
 140         uint16_t i, used_idx, desc_idx;
 141         for (i = 0; i < num; i++) {
 142                 struct vring_used_elem *uep;
 143                 struct vq_desc_extra *dxp;
 144
 145                 used_idx = (uint16_t)(vq->vq_used_cons_idx & (vq->vq_nentries - 1));
 146                 uep = &vq->vq_ring.used->ring[used_idx];
 147
 148                 desc_idx = (uint16_t) uep->id;
 149                 dxp = &vq->vq_descx[desc_idx];
 150                 vq->vq_used_cons_idx++;
 151                 vq_ring_free_chain(vq, desc_idx);
 152
 153                 if (dxp->cookie != NULL) {
 154                         rte_pktmbuf_free(dxp->cookie);
 155                         dxp->cookie = NULL;
 156                 }
 157         }
 158 }
 159
 160
 161 static inline int
 162 virtqueue_enqueue_recv_refill(struct virtqueue *vq, struct rte_mbuf *cookie)
 163 {
 164         struct vq_desc_extra *dxp;
 165         struct virtio_hw *hw = vq->hw;
 166         struct vring_desc *start_dp;
 167         uint16_t needed = 1;
 168         uint16_t head_idx, idx;
 169
 170         if (unlikely(vq->vq_free_cnt == 0))
 171                 return -ENOSPC;
 172         if (unlikely(vq->vq_free_cnt < needed))
 173                 return -EMSGSIZE;
 174
 175         head_idx = vq->vq_desc_head_idx;
 176         if (unlikely(head_idx >= vq->vq_nentries))
 177                 return -EFAULT;
 178
 179         idx = head_idx;
 180         dxp = &vq->vq_descx[idx];
 181         dxp->cookie = (void *)cookie;
 182         dxp->ndescs = needed;
 183
 184         start_dp = vq->vq_ring.desc;
 185         start_dp[idx].addr =
 186                 (uint64_t)(cookie->buf_physaddr + RTE_PKTMBUF_HEADROOM
 187                 - hw->vtnet_hdr_size);
 188         start_dp[idx].len =
 189                 cookie->buf_len - RTE_PKTMBUF_HEADROOM + hw->vtnet_hdr_size;
 190         start_dp[idx].flags =  VRING_DESC_F_WRITE;
 191         idx = start_dp[idx].next;
 192         vq->vq_desc_head_idx = idx;
 193         if (vq->vq_desc_head_idx == VQ_RING_DESC_CHAIN_END)
 194                 vq->vq_desc_tail_idx = idx;
 195         vq->vq_free_cnt = (uint16_t)(vq->vq_free_cnt - needed);
 196         vq_update_avail_ring(vq, head_idx);
 197
 198         return 0;
 199 }
 200
 201 static int
 202 virtqueue_enqueue_xmit(struct virtqueue *txvq, struct rte_mbuf *cookie)
 203 {
 204         struct vq_desc_extra *dxp;
 205         struct vring_desc *start_dp;
 206         uint16_t seg_num = cookie->nb_segs;
 207         uint16_t needed = 1 + seg_num;
 208         uint16_t head_idx, idx;
 209         uint16_t head_size = txvq->hw->vtnet_hdr_size;
 210
 211         if (unlikely(txvq->vq_free_cnt == 0))
 212                 return -ENOSPC;
 213         if (unlikely(txvq->vq_free_cnt < needed))
 214                 return -EMSGSIZE;
 215         head_idx = txvq->vq_desc_head_idx;
 216         if (unlikely(head_idx >= txvq->vq_nentries))
 217                 return -EFAULT;
 218
 219         idx = head_idx;
 220         dxp = &txvq->vq_descx[idx];
 221         dxp->cookie = (void *)cookie;
 222         dxp->ndescs = needed;
 223
 224         start_dp = txvq->vq_ring.desc;
 225         start_dp[idx].addr =
 226                 txvq->virtio_net_hdr_mem + idx * head_size;
 227         start_dp[idx].len = (uint32_t)head_size;
 228         start_dp[idx].flags = VRING_DESC_F_NEXT;
 229
 230         for (; ((seg_num > 0) && (cookie != NULL)); seg_num--) {
 231                 idx = start_dp[idx].next;
 232                 start_dp[idx].addr  = RTE_MBUF_DATA_DMA_ADDR(cookie);
 233                 start_dp[idx].len   = cookie->data_len;
 234                 start_dp[idx].flags = VRING_DESC_F_NEXT;
 235                 cookie = cookie->next;
 236         }
 237
 238         start_dp[idx].flags &= ~VRING_DESC_F_NEXT;
 239         idx = start_dp[idx].next;
 240         txvq->vq_desc_head_idx = idx;
 241         if (txvq->vq_desc_head_idx == VQ_RING_DESC_CHAIN_END)
 242                 txvq->vq_desc_tail_idx = idx;
 243         txvq->vq_free_cnt = (uint16_t)(txvq->vq_free_cnt - needed);
 244         vq_update_avail_ring(txvq, head_idx);
 245
 246         return 0;
 247 }
 248
 249 static inline struct rte_mbuf *
 250 rte_rxmbuf_alloc(struct rte_mempool *mp)
 251 {
 252         struct rte_mbuf *m;
 253
 254         m = __rte_mbuf_raw_alloc(mp);
 255         __rte_mbuf_sanity_check_raw(m, 0);
 256
 257         return m;
 258 }
 259
 260 static void
 261 virtio_dev_vring_start(struct virtqueue *vq, int queue_type)
 262 {
 263         struct rte_mbuf *m;
 264         int i, nbufs, error, size = vq->vq_nentries;
 265         struct vring *vr = &vq->vq_ring;
 266         uint8_t *ring_mem = vq->vq_ring_virt_mem;
 267
 268         PMD_INIT_FUNC_TRACE();
 269
 270         /*
 271          * Reinitialise since virtio port might have been stopped and restarted
 272          */
 273         memset(vq->vq_ring_virt_mem, 0, vq->vq_ring_size);
 274         vring_init(vr, size, ring_mem, VIRTIO_PCI_VRING_ALIGN);
 275         vq->vq_used_cons_idx = 0;
 276         vq->vq_desc_head_idx = 0;
 277         vq->vq_avail_idx = 0;
 278         vq->vq_desc_tail_idx = (uint16_t)(vq->vq_nentries - 1);
 279         vq->vq_free_cnt = vq->vq_nentries;
 280         memset(vq->vq_descx, 0, sizeof(struct vq_desc_extra) * vq->vq_nentries);
 281
 282         /* Chain all the descriptors in the ring with an END */
 283         for (i = 0; i < size - 1; i++)
 284                 vr->desc[i].next = (uint16_t)(i + 1);
 285         vr->desc[i].next = VQ_RING_DESC_CHAIN_END;
 286
 287         /*
 288          * Disable device(host) interrupting guest
 289          */
 290         virtqueue_disable_intr(vq);
 291
 292         /* Only rx virtqueue needs mbufs to be allocated at initialization */
 293         if (queue_type == VTNET_RQ) {
 294                 if (vq->mpool == NULL)
 295                         rte_exit(EXIT_FAILURE,
 296                         "Cannot allocate initial mbufs for rx virtqueue");
 297
 298                 /* Allocate blank mbufs for the each rx descriptor */
 299                 nbufs = 0;
 300                 error = ENOSPC;
 301                 while (!virtqueue_full(vq)) {
 302                         m = rte_rxmbuf_alloc(vq->mpool);
 303                         if (m == NULL)
 304                                 break;
 305
 306                         /******************************************
 307                         *         Enqueue allocated buffers        *
 308                         *******************************************/
 309                         error = virtqueue_enqueue_recv_refill(vq, m);
 310
 311                         if (error) {
 312                                 rte_pktmbuf_free(m);
 313                                 break;
 314                         }
 315                         nbufs++;
 316                 }
 317
 318                 vq_update_avail_idx(vq);
 319
 320                 PMD_INIT_LOG(DEBUG, "Allocated %d bufs", nbufs);
 321
 322                 VIRTIO_WRITE_REG_2(vq->hw, VIRTIO_PCI_QUEUE_SEL,
 323                         vq->vq_queue_index);
 324                 VIRTIO_WRITE_REG_4(vq->hw, VIRTIO_PCI_QUEUE_PFN,
 325                         vq->mz->phys_addr >> VIRTIO_PCI_QUEUE_ADDR_SHIFT);
 326         } else if (queue_type == VTNET_TQ) {
 327                 VIRTIO_WRITE_REG_2(vq->hw, VIRTIO_PCI_QUEUE_SEL,
 328                         vq->vq_queue_index);
 329                 VIRTIO_WRITE_REG_4(vq->hw, VIRTIO_PCI_QUEUE_PFN,
 330                         vq->mz->phys_addr >> VIRTIO_PCI_QUEUE_ADDR_SHIFT);
 331         } else {
 332                 VIRTIO_WRITE_REG_2(vq->hw, VIRTIO_PCI_QUEUE_SEL,
 333                         vq->vq_queue_index);
 334                 VIRTIO_WRITE_REG_4(vq->hw, VIRTIO_PCI_QUEUE_PFN,
 335                         vq->mz->phys_addr >> VIRTIO_PCI_QUEUE_ADDR_SHIFT);
 336         }
 337 }
 338
 339 void
 340 virtio_dev_cq_start(struct rte_eth_dev *dev)
 341 {
 342         struct virtio_hw *hw = dev->data->dev_private;
 343
 344         if (hw->cvq) {
 345                 virtio_dev_vring_start(hw->cvq, VTNET_CQ);
 346                 VIRTQUEUE_DUMP((struct virtqueue *)hw->cvq);
 347         }
 348 }
 349
 350 void
 351 virtio_dev_rxtx_start(struct rte_eth_dev *dev)
 352 {
 353         /*
 354          * Start receive and transmit vrings
 355          * -    Setup vring structure for all queues
 356          * -    Initialize descriptor for the rx vring
 357          * -    Allocate blank mbufs for the each rx descriptor
 358          *
 359          */
 360         int i;
 361
 362         PMD_INIT_FUNC_TRACE();
 363
 364         /* Start rx vring. */
 365         for (i = 0; i < dev->data->nb_rx_queues; i++) {
 366                 virtio_dev_vring_start(dev->data->rx_queues[i], VTNET_RQ);
 367                 VIRTQUEUE_DUMP((struct virtqueue *)dev->data->rx_queues[i]);
 368         }
 369
 370         /* Start tx vring. */
 371         for (i = 0; i < dev->data->nb_tx_queues; i++) {
 372                 virtio_dev_vring_start(dev->data->tx_queues[i], VTNET_TQ);
 373                 VIRTQUEUE_DUMP((struct virtqueue *)dev->data->tx_queues[i]);
 374         }
 375 }
 376
 377 int
 378 virtio_dev_rx_queue_setup(struct rte_eth_dev *dev,
 379                         uint16_t queue_idx,
 380                         uint16_t nb_desc,
 381                         unsigned int socket_id,
 382                         __rte_unused const struct rte_eth_rxconf *rx_conf,
 383                         struct rte_mempool *mp)
 384 {
 385         uint16_t vtpci_queue_idx = 2 * queue_idx + VTNET_SQ_RQ_QUEUE_IDX;
 386         struct virtqueue *vq;
 387         int ret;
 388
 389         PMD_INIT_FUNC_TRACE();
 390         ret = virtio_dev_queue_setup(dev, VTNET_RQ, queue_idx, vtpci_queue_idx,
 391                         nb_desc, socket_id, &vq);
 392         if (ret < 0) {
 393                 PMD_INIT_LOG(ERR, "tvq initialization failed");
 394                 return ret;
 395         }
 396
 397         /* Create mempool for rx mbuf allocation */
 398         vq->mpool = mp;
 399
 400         dev->data->rx_queues[queue_idx] = vq;
 401         return 0;
 402 }
 403
 404 /*
 405  * struct rte_eth_dev *dev: Used to update dev
 406  * uint16_t nb_desc: Defaults to values read from config space
 407  * unsigned int socket_id: Used to allocate memzone
 408  * const struct rte_eth_txconf *tx_conf: Used to setup tx engine
 409  * uint16_t queue_idx: Just used as an index in dev txq list
 410  */
 411 int
 412 virtio_dev_tx_queue_setup(struct rte_eth_dev *dev,
 413                         uint16_t queue_idx,
 414                         uint16_t nb_desc,
 415                         unsigned int socket_id,
 416                         const struct rte_eth_txconf *tx_conf)
 417 {
 418         uint8_t vtpci_queue_idx = 2 * queue_idx + VTNET_SQ_TQ_QUEUE_IDX;
 419         struct virtqueue *vq;
 420         uint16_t tx_free_thresh;
 421         int ret;
 422
 423         PMD_INIT_FUNC_TRACE();
 424
 425         if ((tx_conf->txq_flags & ETH_TXQ_FLAGS_NOXSUMS)
 426             != ETH_TXQ_FLAGS_NOXSUMS) {
 427                 PMD_INIT_LOG(ERR, "TX checksum offload not supported\n");
 428                 return -EINVAL;
 429         }
 430
 431         ret = virtio_dev_queue_setup(dev, VTNET_TQ, queue_idx, vtpci_queue_idx,
 432                         nb_desc, socket_id, &vq);
 433         if (ret < 0) {
 434                 PMD_INIT_LOG(ERR, "rvq initialization failed");
 435                 return ret;
 436         }
 437
 438         tx_free_thresh = tx_conf->tx_free_thresh;
 439         if (tx_free_thresh == 0)
 440                 tx_free_thresh =
 441                         RTE_MIN(vq->vq_nentries / 4, DEFAULT_TX_FREE_THRESH);
 442
 443         if (tx_free_thresh >= (vq->vq_nentries - 3)) {
 444                 RTE_LOG(ERR, PMD, "tx_free_thresh must be less than the "
 445                         "number of TX entries minus 3 (%u)."
 446                         " (tx_free_thresh=%u port=%u queue=%u)\n",
 447                         vq->vq_nentries - 3,
 448                         tx_free_thresh, dev->data->port_id, queue_idx);
 449                 return -EINVAL;
 450         }
 451
 452         vq->vq_free_thresh = tx_free_thresh;
 453
 454         dev->data->tx_queues[queue_idx] = vq;
 455         return 0;
 456 }
 457
 458 static void
 459 virtio_discard_rxbuf(struct virtqueue *vq, struct rte_mbuf *m)
 460 {
 461         int error;
 462         /*
 463          * Requeue the discarded mbuf. This should always be
 464          * successful since it was just dequeued.
 465          */
 466         error = virtqueue_enqueue_recv_refill(vq, m);
 467         if (unlikely(error)) {
 468                 RTE_LOG(ERR, PMD, "cannot requeue discarded mbuf");
 469                 rte_pktmbuf_free(m);
 470         }
 471 }
 472
 473 #define VIRTIO_MBUF_BURST_SZ 64
 474 #define DESC_PER_CACHELINE (RTE_CACHE_LINE_SIZE / sizeof(struct vring_desc))
 475 uint16_t
 476 virtio_recv_pkts(void *rx_queue, struct rte_mbuf **rx_pkts, uint16_t nb_pkts)
 477 {
 478         struct virtqueue *rxvq = rx_queue;
 479         struct virtio_hw *hw;
 480         struct rte_mbuf *rxm, *new_mbuf;
 481         uint16_t nb_used, num, nb_rx;
 482         uint32_t len[VIRTIO_MBUF_BURST_SZ];
 483         struct rte_mbuf *rcv_pkts[VIRTIO_MBUF_BURST_SZ];
 484         int error;
 485         uint32_t i, nb_enqueued;
 486         const uint32_t hdr_size = sizeof(struct virtio_net_hdr);
 487
 488         nb_used = VIRTQUEUE_NUSED(rxvq);
 489
 490         virtio_rmb();
 491
 492         num = (uint16_t)(likely(nb_used <= nb_pkts) ? nb_used : nb_pkts);
 493         num = (uint16_t)(likely(num <= VIRTIO_MBUF_BURST_SZ) ? num : VIRTIO_MBUF_BURST_SZ);
 494         if (likely(num > DESC_PER_CACHELINE))
 495                 num = num - ((rxvq->vq_used_cons_idx + num) % DESC_PER_CACHELINE);
 496
 497         if (num == 0)
 498                 return 0;
 499
 500         num = virtqueue_dequeue_burst_rx(rxvq, rcv_pkts, len, num);
 501         PMD_RX_LOG(DEBUG, "used:%d dequeue:%d", nb_used, num);
 502
 503         hw = rxvq->hw;
 504         nb_rx = 0;
 505         nb_enqueued = 0;
 506
 507         for (i = 0; i < num ; i++) {
 508                 rxm = rcv_pkts[i];
 509
 510                 PMD_RX_LOG(DEBUG, "packet len:%d", len[i]);
 511
 512                 if (unlikely(len[i] < hdr_size + ETHER_HDR_LEN)) {
 513                         PMD_RX_LOG(ERR, "Packet drop");
 514                         nb_enqueued++;
 515                         virtio_discard_rxbuf(rxvq, rxm);
 516                         rxvq->errors++;
 517                         continue;
 518                 }
 519
 520                 rxm->port = rxvq->port_id;
 521                 rxm->data_off = RTE_PKTMBUF_HEADROOM;
 522
 523                 rxm->nb_segs = 1;
 524                 rxm->next = NULL;
 525                 rxm->pkt_len = (uint32_t)(len[i] - hdr_size);
 526                 rxm->data_len = (uint16_t)(len[i] - hdr_size);
 527
 528                 if (hw->vlan_strip)
 529                         rte_vlan_strip(rxm);
 530
 531                 VIRTIO_DUMP_PACKET(rxm, rxm->data_len);
 532
 533                 rx_pkts[nb_rx++] = rxm;
 534                 rxvq->bytes += rx_pkts[nb_rx - 1]->pkt_len;
 535         }
 536
 537         rxvq->packets += nb_rx;
 538
 539         /* Allocate new mbuf for the used descriptor */
 540         error = ENOSPC;
 541         while (likely(!virtqueue_full(rxvq))) {
 542                 new_mbuf = rte_rxmbuf_alloc(rxvq->mpool);
 543                 if (unlikely(new_mbuf == NULL)) {
 544                         struct rte_eth_dev *dev
 545                                 = &rte_eth_devices[rxvq->port_id];
 546                         dev->data->rx_mbuf_alloc_failed++;
 547                         break;
 548                 }
 549                 error = virtqueue_enqueue_recv_refill(rxvq, new_mbuf);
 550                 if (unlikely(error)) {
 551                         rte_pktmbuf_free(new_mbuf);
 552                         break;
 553                 }
 554                 nb_enqueued++;
 555         }
 556
 557         if (likely(nb_enqueued)) {
 558                 vq_update_avail_idx(rxvq);
 559
 560                 if (unlikely(virtqueue_kick_prepare(rxvq))) {
 561                         virtqueue_notify(rxvq);
 562                         PMD_RX_LOG(DEBUG, "Notified\n");
 563                 }
 564         }
 565
 566         return nb_rx;
 567 }
 568
 569 uint16_t
 570 virtio_recv_mergeable_pkts(void *rx_queue,
 571                         struct rte_mbuf **rx_pkts,
 572                         uint16_t nb_pkts)
 573 {
 574         struct virtqueue *rxvq = rx_queue;
 575         struct virtio_hw *hw;
 576         struct rte_mbuf *rxm, *new_mbuf;
 577         uint16_t nb_used, num, nb_rx;
 578         uint32_t len[VIRTIO_MBUF_BURST_SZ];
 579         struct rte_mbuf *rcv_pkts[VIRTIO_MBUF_BURST_SZ];
 580         struct rte_mbuf *prev;
 581         int error;
 582         uint32_t i, nb_enqueued;
 583         uint32_t seg_num;
 584         uint16_t extra_idx;
 585         uint32_t seg_res;
 586         const uint32_t hdr_size = sizeof(struct virtio_net_hdr_mrg_rxbuf);
 587
 588         nb_used = VIRTQUEUE_NUSED(rxvq);
 589
 590         virtio_rmb();
 591
 592         if (nb_used == 0)
 593                 return 0;
 594
 595         PMD_RX_LOG(DEBUG, "used:%d\n", nb_used);
 596
 597         hw = rxvq->hw;
 598         nb_rx = 0;
 599         i = 0;
 600         nb_enqueued = 0;
 601         seg_num = 0;
 602         extra_idx = 0;
 603         seg_res = 0;
 604
 605         while (i < nb_used) {
 606                 struct virtio_net_hdr_mrg_rxbuf *header;
 607
 608                 if (nb_rx == nb_pkts)
 609                         break;
 610
 611                 num = virtqueue_dequeue_burst_rx(rxvq, rcv_pkts, len, 1);
 612                 if (num != 1)
 613                         continue;
 614
 615                 i++;
 616
 617                 PMD_RX_LOG(DEBUG, "dequeue:%d\n", num);
 618                 PMD_RX_LOG(DEBUG, "packet len:%d\n", len[0]);
 619
 620                 rxm = rcv_pkts[0];
 621
 622                 if (unlikely(len[0] < hdr_size + ETHER_HDR_LEN)) {
 623                         PMD_RX_LOG(ERR, "Packet drop\n");
 624                         nb_enqueued++;
 625                         virtio_discard_rxbuf(rxvq, rxm);
 626                         rxvq->errors++;
 627                         continue;
 628                 }
 629
 630                 header = (struct virtio_net_hdr_mrg_rxbuf *)((char *)rxm->buf_addr +
 631                         RTE_PKTMBUF_HEADROOM - hdr_size);
 632                 seg_num = header->num_buffers;
 633
 634                 if (seg_num == 0)
 635                         seg_num = 1;
 636
 637                 rxm->data_off = RTE_PKTMBUF_HEADROOM;
 638                 rxm->nb_segs = seg_num;
 639                 rxm->next = NULL;
 640                 rxm->pkt_len = (uint32_t)(len[0] - hdr_size);
 641                 rxm->data_len = (uint16_t)(len[0] - hdr_size);
 642
 643                 rxm->port = rxvq->port_id;
 644                 rx_pkts[nb_rx] = rxm;
 645                 prev = rxm;
 646
 647                 seg_res = seg_num - 1;
 648
 649                 while (seg_res != 0) {
 650                         /*
 651                          * Get extra segments for current uncompleted packet.
 652                          */
 653                         uint16_t  rcv_cnt =
 654                                 RTE_MIN(seg_res, RTE_DIM(rcv_pkts));
 655                         if (likely(VIRTQUEUE_NUSED(rxvq) >= rcv_cnt)) {
 656                                 uint32_t rx_num =
 657                                         virtqueue_dequeue_burst_rx(rxvq,
 658                                         rcv_pkts, len, rcv_cnt);
 659                                 i += rx_num;
 660                                 rcv_cnt = rx_num;
 661                         } else {
 662                                 PMD_RX_LOG(ERR,
 663                                         "No enough segments for packet.\n");
 664                                 nb_enqueued++;
 665                                 virtio_discard_rxbuf(rxvq, rxm);
 666                                 rxvq->errors++;
 667                                 break;
 668                         }
 669
 670                         extra_idx = 0;
 671
 672                         while (extra_idx < rcv_cnt) {
 673                                 rxm = rcv_pkts[extra_idx];
 674
 675                                 rxm->data_off = RTE_PKTMBUF_HEADROOM - hdr_size;
 676                                 rxm->next = NULL;
 677                                 rxm->pkt_len = (uint32_t)(len[extra_idx]);
 678                                 rxm->data_len = (uint16_t)(len[extra_idx]);
 679
 680                                 if (prev)
 681                                         prev->next = rxm;
 682
 683                                 prev = rxm;
 684                                 rx_pkts[nb_rx]->pkt_len += rxm->pkt_len;
 685                                 extra_idx++;
 686                         };
 687                         seg_res -= rcv_cnt;
 688                 }
 689
 690                 if (hw->vlan_strip)
 691                         rte_vlan_strip(rx_pkts[nb_rx]);
 692
 693                 VIRTIO_DUMP_PACKET(rx_pkts[nb_rx],
 694                         rx_pkts[nb_rx]->data_len);
 695
 696                 rxvq->bytes += rx_pkts[nb_rx]->pkt_len;
 697                 nb_rx++;
 698         }
 699
 700         rxvq->packets += nb_rx;
 701
 702         /* Allocate new mbuf for the used descriptor */
 703         error = ENOSPC;
 704         while (likely(!virtqueue_full(rxvq))) {
 705                 new_mbuf = rte_rxmbuf_alloc(rxvq->mpool);
 706                 if (unlikely(new_mbuf == NULL)) {
 707                         struct rte_eth_dev *dev
 708                                 = &rte_eth_devices[rxvq->port_id];
 709                         dev->data->rx_mbuf_alloc_failed++;
 710                         break;
 711                 }
 712                 error = virtqueue_enqueue_recv_refill(rxvq, new_mbuf);
 713                 if (unlikely(error)) {
 714                         rte_pktmbuf_free(new_mbuf);
 715                         break;
 716                 }
 717                 nb_enqueued++;
 718         }
 719
 720         if (likely(nb_enqueued)) {
 721                 vq_update_avail_idx(rxvq);
 722
 723                 if (unlikely(virtqueue_kick_prepare(rxvq))) {
 724                         virtqueue_notify(rxvq);
 725                         PMD_RX_LOG(DEBUG, "Notified");
 726                 }
 727         }
 728
 729         return nb_rx;
 730 }
 731
 732 uint16_t
 733 virtio_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts, uint16_t nb_pkts)
 734 {
 735         struct virtqueue *txvq = tx_queue;
 736         struct rte_mbuf *txm;
 737         uint16_t nb_used, nb_tx;
 738         int error;
 739
 740         if (unlikely(nb_pkts < 1))
 741                 return nb_pkts;
 742
 743         PMD_TX_LOG(DEBUG, "%d packets to xmit", nb_pkts);
 744         nb_used = VIRTQUEUE_NUSED(txvq);
 745
 746         virtio_rmb();
 747         if (likely(nb_used > txvq->vq_nentries - txvq->vq_free_thresh))
 748                 virtio_xmit_cleanup(txvq, nb_used);
 749
 750         nb_tx = 0;
 751
 752         while (nb_tx < nb_pkts) {
 753                 /* Need one more descriptor for virtio header. */
 754                 int need = tx_pkts[nb_tx]->nb_segs - txvq->vq_free_cnt + 1;
 755
 756                 /*Positive value indicates it need free vring descriptors */
 757                 if (unlikely(need > 0)) {
 758                         nb_used = VIRTQUEUE_NUSED(txvq);
 759                         virtio_rmb();
 760                         need = RTE_MIN(need, (int)nb_used);
 761
 762                         virtio_xmit_cleanup(txvq, need);
 763                         need = (int)tx_pkts[nb_tx]->nb_segs -
 764                                 txvq->vq_free_cnt + 1;
 765                 }
 766
 767                 /*
 768                  * Zero or negative value indicates it has enough free
 769                  * descriptors to use for transmitting.
 770                  */
 771                 if (likely(need <= 0)) {
 772                         txm = tx_pkts[nb_tx];
 773
 774                         /* Do VLAN tag insertion */
 775                         if (unlikely(txm->ol_flags & PKT_TX_VLAN_PKT)) {
 776                                 error = rte_vlan_insert(&txm);
 777                                 if (unlikely(error)) {
 778                                         rte_pktmbuf_free(txm);
 779                                         ++nb_tx;
 780                                         continue;
 781                                 }
 782                         }
 783
 784                         /* Enqueue Packet buffers */
 785                         error = virtqueue_enqueue_xmit(txvq, txm);
 786                         if (unlikely(error)) {
 787                                 if (error == ENOSPC)
 788                                         PMD_TX_LOG(ERR, "virtqueue_enqueue Free count = 0");
 789                                 else if (error == EMSGSIZE)
 790                                         PMD_TX_LOG(ERR, "virtqueue_enqueue Free count < 1");
 791                                 else
 792                                         PMD_TX_LOG(ERR, "virtqueue_enqueue error: %d", error);
 793                                 break;
 794                         }
 795                         nb_tx++;
 796                         txvq->bytes += txm->pkt_len;
 797                 } else {
 798                         PMD_TX_LOG(ERR, "No free tx descriptors to transmit");
 799                         break;
 800                 }
 801         }
 802
 803         txvq->packets += nb_tx;
 804
 805         if (likely(nb_tx)) {
 806                 vq_update_avail_idx(txvq);
 807
 808                 if (unlikely(virtqueue_kick_prepare(txvq))) {
 809                         virtqueue_notify(txvq);
 810                         PMD_TX_LOG(DEBUG, "Notified backend after xmit");
 811                 }
 812         }
 813
 814         return nb_tx;
 815 }