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         size_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 = 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, "rvq 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 void
 405 virtio_dev_rx_queue_release(void *rxq)
 406 {
 407         virtio_dev_queue_release(rxq);
 408 }
 409
 410 /*
 411  * struct rte_eth_dev *dev: Used to update dev
 412  * uint16_t nb_desc: Defaults to values read from config space
 413  * unsigned int socket_id: Used to allocate memzone
 414  * const struct rte_eth_txconf *tx_conf: Used to setup tx engine
 415  * uint16_t queue_idx: Just used as an index in dev txq list
 416  */
 417 int
 418 virtio_dev_tx_queue_setup(struct rte_eth_dev *dev,
 419                         uint16_t queue_idx,
 420                         uint16_t nb_desc,
 421                         unsigned int socket_id,
 422                         const struct rte_eth_txconf *tx_conf)
 423 {
 424         uint8_t vtpci_queue_idx = 2 * queue_idx + VTNET_SQ_TQ_QUEUE_IDX;
 425         struct virtqueue *vq;
 426         uint16_t tx_free_thresh;
 427         int ret;
 428
 429         PMD_INIT_FUNC_TRACE();
 430
 431         if ((tx_conf->txq_flags & ETH_TXQ_FLAGS_NOXSUMS)
 432             != ETH_TXQ_FLAGS_NOXSUMS) {
 433                 PMD_INIT_LOG(ERR, "TX checksum offload not supported\n");
 434                 return -EINVAL;
 435         }
 436
 437         ret = virtio_dev_queue_setup(dev, VTNET_TQ, queue_idx, vtpci_queue_idx,
 438                         nb_desc, socket_id, &vq);
 439         if (ret < 0) {
 440                 PMD_INIT_LOG(ERR, "rvq initialization failed");
 441                 return ret;
 442         }
 443
 444         tx_free_thresh = tx_conf->tx_free_thresh;
 445         if (tx_free_thresh == 0)
 446                 tx_free_thresh =
 447                         RTE_MIN(vq->vq_nentries / 4, DEFAULT_TX_FREE_THRESH);
 448
 449         if (tx_free_thresh >= (vq->vq_nentries - 3)) {
 450                 RTE_LOG(ERR, PMD, "tx_free_thresh must be less than the "
 451                         "number of TX entries minus 3 (%u)."
 452                         " (tx_free_thresh=%u port=%u queue=%u)\n",
 453                         vq->vq_nentries - 3,
 454                         tx_free_thresh, dev->data->port_id, queue_idx);
 455                 return -EINVAL;
 456         }
 457
 458         vq->vq_free_thresh = tx_free_thresh;
 459
 460         dev->data->tx_queues[queue_idx] = vq;
 461         return 0;
 462 }
 463
 464 void
 465 virtio_dev_tx_queue_release(void *txq)
 466 {
 467         virtio_dev_queue_release(txq);
 468 }
 469
 470 static void
 471 virtio_discard_rxbuf(struct virtqueue *vq, struct rte_mbuf *m)
 472 {
 473         int error;
 474         /*
 475          * Requeue the discarded mbuf. This should always be
 476          * successful since it was just dequeued.
 477          */
 478         error = virtqueue_enqueue_recv_refill(vq, m);
 479         if (unlikely(error)) {
 480                 RTE_LOG(ERR, PMD, "cannot requeue discarded mbuf");
 481                 rte_pktmbuf_free(m);
 482         }
 483 }
 484
 485 #define VIRTIO_MBUF_BURST_SZ 64
 486 #define DESC_PER_CACHELINE (RTE_CACHE_LINE_SIZE / sizeof(struct vring_desc))
 487 uint16_t
 488 virtio_recv_pkts(void *rx_queue, struct rte_mbuf **rx_pkts, uint16_t nb_pkts)
 489 {
 490         struct virtqueue *rxvq = rx_queue;
 491         struct virtio_hw *hw;
 492         struct rte_mbuf *rxm, *new_mbuf;
 493         uint16_t nb_used, num, nb_rx;
 494         uint32_t len[VIRTIO_MBUF_BURST_SZ];
 495         struct rte_mbuf *rcv_pkts[VIRTIO_MBUF_BURST_SZ];
 496         int error;
 497         uint32_t i, nb_enqueued;
 498         const uint32_t hdr_size = sizeof(struct virtio_net_hdr);
 499
 500         nb_used = VIRTQUEUE_NUSED(rxvq);
 501
 502         virtio_rmb();
 503
 504         num = (uint16_t)(likely(nb_used <= nb_pkts) ? nb_used : nb_pkts);
 505         num = (uint16_t)(likely(num <= VIRTIO_MBUF_BURST_SZ) ? num : VIRTIO_MBUF_BURST_SZ);
 506         if (likely(num > DESC_PER_CACHELINE))
 507                 num = num - ((rxvq->vq_used_cons_idx + num) % DESC_PER_CACHELINE);
 508
 509         if (num == 0)
 510                 return 0;
 511
 512         num = virtqueue_dequeue_burst_rx(rxvq, rcv_pkts, len, num);
 513         PMD_RX_LOG(DEBUG, "used:%d dequeue:%d", nb_used, num);
 514
 515         hw = rxvq->hw;
 516         nb_rx = 0;
 517         nb_enqueued = 0;
 518
 519         for (i = 0; i < num ; i++) {
 520                 rxm = rcv_pkts[i];
 521
 522                 PMD_RX_LOG(DEBUG, "packet len:%d", len[i]);
 523
 524                 if (unlikely(len[i] < hdr_size + ETHER_HDR_LEN)) {
 525                         PMD_RX_LOG(ERR, "Packet drop");
 526                         nb_enqueued++;
 527                         virtio_discard_rxbuf(rxvq, rxm);
 528                         rxvq->errors++;
 529                         continue;
 530                 }
 531
 532                 rxm->port = rxvq->port_id;
 533                 rxm->data_off = RTE_PKTMBUF_HEADROOM;
 534
 535                 rxm->nb_segs = 1;
 536                 rxm->next = NULL;
 537                 rxm->pkt_len = (uint32_t)(len[i] - hdr_size);
 538                 rxm->data_len = (uint16_t)(len[i] - hdr_size);
 539
 540                 if (hw->vlan_strip)
 541                         rte_vlan_strip(rxm);
 542
 543                 VIRTIO_DUMP_PACKET(rxm, rxm->data_len);
 544
 545                 rx_pkts[nb_rx++] = rxm;
 546                 rxvq->bytes += rx_pkts[nb_rx - 1]->pkt_len;
 547         }
 548
 549         rxvq->packets += nb_rx;
 550
 551         /* Allocate new mbuf for the used descriptor */
 552         error = ENOSPC;
 553         while (likely(!virtqueue_full(rxvq))) {
 554                 new_mbuf = rte_rxmbuf_alloc(rxvq->mpool);
 555                 if (unlikely(new_mbuf == NULL)) {
 556                         struct rte_eth_dev *dev
 557                                 = &rte_eth_devices[rxvq->port_id];
 558                         dev->data->rx_mbuf_alloc_failed++;
 559                         break;
 560                 }
 561                 error = virtqueue_enqueue_recv_refill(rxvq, new_mbuf);
 562                 if (unlikely(error)) {
 563                         rte_pktmbuf_free(new_mbuf);
 564                         break;
 565                 }
 566                 nb_enqueued++;
 567         }
 568
 569         if (likely(nb_enqueued)) {
 570                 vq_update_avail_idx(rxvq);
 571
 572                 if (unlikely(virtqueue_kick_prepare(rxvq))) {
 573                         virtqueue_notify(rxvq);
 574                         PMD_RX_LOG(DEBUG, "Notified\n");
 575                 }
 576         }
 577
 578         return nb_rx;
 579 }
 580
 581 uint16_t
 582 virtio_recv_mergeable_pkts(void *rx_queue,
 583                         struct rte_mbuf **rx_pkts,
 584                         uint16_t nb_pkts)
 585 {
 586         struct virtqueue *rxvq = rx_queue;
 587         struct virtio_hw *hw;
 588         struct rte_mbuf *rxm, *new_mbuf;
 589         uint16_t nb_used, num, nb_rx;
 590         uint32_t len[VIRTIO_MBUF_BURST_SZ];
 591         struct rte_mbuf *rcv_pkts[VIRTIO_MBUF_BURST_SZ];
 592         struct rte_mbuf *prev;
 593         int error;
 594         uint32_t i, nb_enqueued;
 595         uint32_t seg_num;
 596         uint16_t extra_idx;
 597         uint32_t seg_res;
 598         const uint32_t hdr_size = sizeof(struct virtio_net_hdr_mrg_rxbuf);
 599
 600         nb_used = VIRTQUEUE_NUSED(rxvq);
 601
 602         virtio_rmb();
 603
 604         if (nb_used == 0)
 605                 return 0;
 606
 607         PMD_RX_LOG(DEBUG, "used:%d\n", nb_used);
 608
 609         hw = rxvq->hw;
 610         nb_rx = 0;
 611         i = 0;
 612         nb_enqueued = 0;
 613         seg_num = 0;
 614         extra_idx = 0;
 615         seg_res = 0;
 616
 617         while (i < nb_used) {
 618                 struct virtio_net_hdr_mrg_rxbuf *header;
 619
 620                 if (nb_rx == nb_pkts)
 621                         break;
 622
 623                 num = virtqueue_dequeue_burst_rx(rxvq, rcv_pkts, len, 1);
 624                 if (num != 1)
 625                         continue;
 626
 627                 i++;
 628
 629                 PMD_RX_LOG(DEBUG, "dequeue:%d\n", num);
 630                 PMD_RX_LOG(DEBUG, "packet len:%d\n", len[0]);
 631
 632                 rxm = rcv_pkts[0];
 633
 634                 if (unlikely(len[0] < hdr_size + ETHER_HDR_LEN)) {
 635                         PMD_RX_LOG(ERR, "Packet drop\n");
 636                         nb_enqueued++;
 637                         virtio_discard_rxbuf(rxvq, rxm);
 638                         rxvq->errors++;
 639                         continue;
 640                 }
 641
 642                 header = (struct virtio_net_hdr_mrg_rxbuf *)((char *)rxm->buf_addr +
 643                         RTE_PKTMBUF_HEADROOM - hdr_size);
 644                 seg_num = header->num_buffers;
 645
 646                 if (seg_num == 0)
 647                         seg_num = 1;
 648
 649                 rxm->data_off = RTE_PKTMBUF_HEADROOM;
 650                 rxm->nb_segs = seg_num;
 651                 rxm->next = NULL;
 652                 rxm->pkt_len = (uint32_t)(len[0] - hdr_size);
 653                 rxm->data_len = (uint16_t)(len[0] - hdr_size);
 654
 655                 rxm->port = rxvq->port_id;
 656                 rx_pkts[nb_rx] = rxm;
 657                 prev = rxm;
 658
 659                 seg_res = seg_num - 1;
 660
 661                 while (seg_res != 0) {
 662                         /*
 663                          * Get extra segments for current uncompleted packet.
 664                          */
 665                         uint16_t  rcv_cnt =
 666                                 RTE_MIN(seg_res, RTE_DIM(rcv_pkts));
 667                         if (likely(VIRTQUEUE_NUSED(rxvq) >= rcv_cnt)) {
 668                                 uint32_t rx_num =
 669                                         virtqueue_dequeue_burst_rx(rxvq,
 670                                         rcv_pkts, len, rcv_cnt);
 671                                 i += rx_num;
 672                                 rcv_cnt = rx_num;
 673                         } else {
 674                                 PMD_RX_LOG(ERR,
 675                                         "No enough segments for packet.\n");
 676                                 nb_enqueued++;
 677                                 virtio_discard_rxbuf(rxvq, rxm);
 678                                 rxvq->errors++;
 679                                 break;
 680                         }
 681
 682                         extra_idx = 0;
 683
 684                         while (extra_idx < rcv_cnt) {
 685                                 rxm = rcv_pkts[extra_idx];
 686
 687                                 rxm->data_off = RTE_PKTMBUF_HEADROOM - hdr_size;
 688                                 rxm->next = NULL;
 689                                 rxm->pkt_len = (uint32_t)(len[extra_idx]);
 690                                 rxm->data_len = (uint16_t)(len[extra_idx]);
 691
 692                                 if (prev)
 693                                         prev->next = rxm;
 694
 695                                 prev = rxm;
 696                                 rx_pkts[nb_rx]->pkt_len += rxm->pkt_len;
 697                                 extra_idx++;
 698                         };
 699                         seg_res -= rcv_cnt;
 700                 }
 701
 702                 if (hw->vlan_strip)
 703                         rte_vlan_strip(rx_pkts[nb_rx]);
 704
 705                 VIRTIO_DUMP_PACKET(rx_pkts[nb_rx],
 706                         rx_pkts[nb_rx]->data_len);
 707
 708                 rxvq->bytes += rx_pkts[nb_rx]->pkt_len;
 709                 nb_rx++;
 710         }
 711
 712         rxvq->packets += nb_rx;
 713
 714         /* Allocate new mbuf for the used descriptor */
 715         error = ENOSPC;
 716         while (likely(!virtqueue_full(rxvq))) {
 717                 new_mbuf = rte_rxmbuf_alloc(rxvq->mpool);
 718                 if (unlikely(new_mbuf == NULL)) {
 719                         struct rte_eth_dev *dev
 720                                 = &rte_eth_devices[rxvq->port_id];
 721                         dev->data->rx_mbuf_alloc_failed++;
 722                         break;
 723                 }
 724                 error = virtqueue_enqueue_recv_refill(rxvq, new_mbuf);
 725                 if (unlikely(error)) {
 726                         rte_pktmbuf_free(new_mbuf);
 727                         break;
 728                 }
 729                 nb_enqueued++;
 730         }
 731
 732         if (likely(nb_enqueued)) {
 733                 vq_update_avail_idx(rxvq);
 734
 735                 if (unlikely(virtqueue_kick_prepare(rxvq))) {
 736                         virtqueue_notify(rxvq);
 737                         PMD_RX_LOG(DEBUG, "Notified");
 738                 }
 739         }
 740
 741         return nb_rx;
 742 }
 743
 744 uint16_t
 745 virtio_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts, uint16_t nb_pkts)
 746 {
 747         struct virtqueue *txvq = tx_queue;
 748         struct rte_mbuf *txm;
 749         uint16_t nb_used, nb_tx;
 750         int error;
 751
 752         if (unlikely(nb_pkts < 1))
 753                 return nb_pkts;
 754
 755         PMD_TX_LOG(DEBUG, "%d packets to xmit", nb_pkts);
 756         nb_used = VIRTQUEUE_NUSED(txvq);
 757
 758         virtio_rmb();
 759         if (likely(nb_used > txvq->vq_nentries - txvq->vq_free_thresh))
 760                 virtio_xmit_cleanup(txvq, nb_used);
 761
 762         nb_tx = 0;
 763
 764         while (nb_tx < nb_pkts) {
 765                 /* Need one more descriptor for virtio header. */
 766                 int need = tx_pkts[nb_tx]->nb_segs - txvq->vq_free_cnt + 1;
 767
 768                 /*Positive value indicates it need free vring descriptors */
 769                 if (unlikely(need > 0)) {
 770                         nb_used = VIRTQUEUE_NUSED(txvq);
 771                         virtio_rmb();
 772                         need = RTE_MIN(need, (int)nb_used);
 773
 774                         virtio_xmit_cleanup(txvq, need);
 775                         need = (int)tx_pkts[nb_tx]->nb_segs -
 776                                 txvq->vq_free_cnt + 1;
 777                 }
 778
 779                 /*
 780                  * Zero or negative value indicates it has enough free
 781                  * descriptors to use for transmitting.
 782                  */
 783                 if (likely(need <= 0)) {
 784                         txm = tx_pkts[nb_tx];
 785
 786                         /* Do VLAN tag insertion */
 787                         if (unlikely(txm->ol_flags & PKT_TX_VLAN_PKT)) {
 788                                 error = rte_vlan_insert(&txm);
 789                                 if (unlikely(error)) {
 790                                         rte_pktmbuf_free(txm);
 791                                         ++nb_tx;
 792                                         continue;
 793                                 }
 794                         }
 795
 796                         /* Enqueue Packet buffers */
 797                         error = virtqueue_enqueue_xmit(txvq, txm);
 798                         if (unlikely(error)) {
 799                                 if (error == ENOSPC)
 800                                         PMD_TX_LOG(ERR, "virtqueue_enqueue Free count = 0");
 801                                 else if (error == EMSGSIZE)
 802                                         PMD_TX_LOG(ERR, "virtqueue_enqueue Free count < 1");
 803                                 else
 804                                         PMD_TX_LOG(ERR, "virtqueue_enqueue error: %d", error);
 805                                 break;
 806                         }
 807                         nb_tx++;
 808                         txvq->bytes += txm->pkt_len;
 809                 } else {
 810                         PMD_TX_LOG(ERR, "No free tx descriptors to transmit");
 811                         break;
 812                 }
 813         }
 814
 815         txvq->packets += nb_tx;
 816
 817         if (likely(nb_tx)) {
 818                 vq_update_avail_idx(txvq);
 819
 820                 if (unlikely(virtqueue_kick_prepare(txvq))) {
 821                         virtqueue_notify(txvq);
 822                         PMD_TX_LOG(DEBUG, "Notified backend after xmit");
 823                 }
 824         }
 825
 826         return nb_tx;
 827 }