drivers/net/xen-netback/interface.c

   1 /*
   2  * Network-device interface management.
   3  *
   4  * Copyright (c) 2004-2005, Keir Fraser
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License version 2
   8  * as published by the Free Software Foundation; or, when distributed
   9  * separately from the Linux kernel or incorporated into other
  10  * software packages, subject to the following license:
  11  *
  12  * Permission is hereby granted, free of charge, to any person obtaining a copy
  13  * of this source file (the "Software"), to deal in the Software without
  14  * restriction, including without limitation the rights to use, copy, modify,
  15  * merge, publish, distribute, sublicense, and/or sell copies of the Software,
  16  * and to permit persons to whom the Software is furnished to do so, subject to
  17  * the following conditions:
  18  *
  19  * The above copyright notice and this permission notice shall be included in
  20  * all copies or substantial portions of the Software.
  21  *
  22  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  23  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  24  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  25  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  26  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  27  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
  28  * IN THE SOFTWARE.
  29  */
  30
  31 #include "common.h"
  32
  33 #include <linux/kthread.h>
  34 #include <linux/sched/task.h>
  35 #include <linux/ethtool.h>
  36 #include <linux/rtnetlink.h>
  37 #include <linux/if_vlan.h>
  38 #include <linux/vmalloc.h>
  39
  40 #include <xen/events.h>
  41 #include <asm/xen/hypercall.h>
  42 #include <xen/balloon.h>
  43
  44 #define XENVIF_QUEUE_LENGTH 32
  45 #define XENVIF_NAPI_WEIGHT  64
  46
  47 /* Number of bytes allowed on the internal guest Rx queue. */
  48 #define XENVIF_RX_QUEUE_BYTES (XEN_NETIF_RX_RING_SIZE/2 * PAGE_SIZE)
  49
  50 /* This function is used to set SKBTX_DEV_ZEROCOPY as well as
  51  * increasing the inflight counter. We need to increase the inflight
  52  * counter because core driver calls into xenvif_zerocopy_callback
  53  * which calls xenvif_skb_zerocopy_complete.
  54  */
  55 void xenvif_skb_zerocopy_prepare(struct xenvif_queue *queue,
  56                                  struct sk_buff *skb)
  57 {
  58         skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY;
  59         atomic_inc(&queue->inflight_packets);
  60 }
  61
  62 void xenvif_skb_zerocopy_complete(struct xenvif_queue *queue)
  63 {
  64         atomic_dec(&queue->inflight_packets);
  65
  66         /* Wake the dealloc thread _after_ decrementing inflight_packets so
  67          * that if kthread_stop() has already been called, the dealloc thread
  68          * does not wait forever with nothing to wake it.
  69          */
  70         wake_up(&queue->dealloc_wq);
  71 }
  72
  73 int xenvif_schedulable(struct xenvif *vif)
  74 {
  75         return netif_running(vif->dev) &&
  76                 test_bit(VIF_STATUS_CONNECTED, &vif->status) &&
  77                 !vif->disabled;
  78 }
  79
  80 static irqreturn_t xenvif_tx_interrupt(int irq, void *dev_id)
  81 {
  82         struct xenvif_queue *queue = dev_id;
  83
  84         if (RING_HAS_UNCONSUMED_REQUESTS(&queue->tx))
  85                 napi_schedule(&queue->napi);
  86
  87         return IRQ_HANDLED;
  88 }
  89
  90 static int xenvif_poll(struct napi_struct *napi, int budget)
  91 {
  92         struct xenvif_queue *queue =
  93                 container_of(napi, struct xenvif_queue, napi);
  94         int work_done;
  95
  96         /* This vif is rogue, we pretend we've there is nothing to do
  97          * for this vif to deschedule it from NAPI. But this interface
  98          * will be turned off in thread context later.
  99          */
 100         if (unlikely(queue->vif->disabled)) {
 101                 napi_complete(napi);
 102                 return 0;
 103         }
 104
 105         work_done = xenvif_tx_action(queue, budget);
 106
 107         if (work_done < budget) {
 108                 napi_complete_done(napi, work_done);
 109                 xenvif_napi_schedule_or_enable_events(queue);
 110         }
 111
 112         return work_done;
 113 }
 114
 115 static irqreturn_t xenvif_rx_interrupt(int irq, void *dev_id)
 116 {
 117         struct xenvif_queue *queue = dev_id;
 118
 119         xenvif_kick_thread(queue);
 120
 121         return IRQ_HANDLED;
 122 }
 123
 124 irqreturn_t xenvif_interrupt(int irq, void *dev_id)
 125 {
 126         xenvif_tx_interrupt(irq, dev_id);
 127         xenvif_rx_interrupt(irq, dev_id);
 128
 129         return IRQ_HANDLED;
 130 }
 131
 132 int xenvif_queue_stopped(struct xenvif_queue *queue)
 133 {
 134         struct net_device *dev = queue->vif->dev;
 135         unsigned int id = queue->id;
 136         return netif_tx_queue_stopped(netdev_get_tx_queue(dev, id));
 137 }
 138
 139 void xenvif_wake_queue(struct xenvif_queue *queue)
 140 {
 141         struct net_device *dev = queue->vif->dev;
 142         unsigned int id = queue->id;
 143         netif_tx_wake_queue(netdev_get_tx_queue(dev, id));
 144 }
 145
 146 static u16 xenvif_select_queue(struct net_device *dev, struct sk_buff *skb,
 147                                void *accel_priv,
 148                                select_queue_fallback_t fallback)
 149 {
 150         struct xenvif *vif = netdev_priv(dev);
 151         unsigned int size = vif->hash.size;
 152
 153         if (vif->hash.alg == XEN_NETIF_CTRL_HASH_ALGORITHM_NONE)
 154                 return fallback(dev, skb) % dev->real_num_tx_queues;
 155
 156         xenvif_set_skb_hash(vif, skb);
 157
 158         if (size == 0)
 159                 return skb_get_hash_raw(skb) % dev->real_num_tx_queues;
 160
 161         return vif->hash.mapping[skb_get_hash_raw(skb) % size];
 162 }
 163
 164 static int xenvif_start_xmit(struct sk_buff *skb, struct net_device *dev)
 165 {
 166         struct xenvif *vif = netdev_priv(dev);
 167         struct xenvif_queue *queue = NULL;
 168         unsigned int num_queues = vif->num_queues;
 169         u16 index;
 170         struct xenvif_rx_cb *cb;
 171
 172         BUG_ON(skb->dev != dev);
 173
 174         /* Drop the packet if queues are not set up */
 175         if (num_queues < 1)
 176                 goto drop;
 177
 178         /* Obtain the queue to be used to transmit this packet */
 179         index = skb_get_queue_mapping(skb);
 180         if (index >= num_queues) {
 181                 pr_warn_ratelimited("Invalid queue %hu for packet on interface %s\n.",
 182                                     index, vif->dev->name);
 183                 index %= num_queues;
 184         }
 185         queue = &vif->queues[index];
 186
 187         /* Drop the packet if queue is not ready */
 188         if (queue->task == NULL ||
 189             queue->dealloc_task == NULL ||
 190             !xenvif_schedulable(vif))
 191                 goto drop;
 192
 193         if (vif->multicast_control && skb->pkt_type == PACKET_MULTICAST) {
 194                 struct ethhdr *eth = (struct ethhdr *)skb->data;
 195
 196                 if (!xenvif_mcast_match(vif, eth->h_dest))
 197                         goto drop;
 198         }
 199
 200         cb = XENVIF_RX_CB(skb);
 201         cb->expires = jiffies + vif->drain_timeout;
 202
 203         /* If there is no hash algorithm configured then make sure there
 204          * is no hash information in the socket buffer otherwise it
 205          * would be incorrectly forwarded to the frontend.
 206          */
 207         if (vif->hash.alg == XEN_NETIF_CTRL_HASH_ALGORITHM_NONE)
 208                 skb_clear_hash(skb);
 209
 210         xenvif_rx_queue_tail(queue, skb);
 211         xenvif_kick_thread(queue);
 212
 213         return NETDEV_TX_OK;
 214
 215  drop:
 216         vif->dev->stats.tx_dropped++;
 217         dev_kfree_skb(skb);
 218         return NETDEV_TX_OK;
 219 }
 220
 221 static struct net_device_stats *xenvif_get_stats(struct net_device *dev)
 222 {
 223         struct xenvif *vif = netdev_priv(dev);
 224         struct xenvif_queue *queue = NULL;
 225         u64 rx_bytes = 0;
 226         u64 rx_packets = 0;
 227         u64 tx_bytes = 0;
 228         u64 tx_packets = 0;
 229         unsigned int index;
 230
 231         spin_lock(&vif->lock);
 232         if (vif->queues == NULL)
 233                 goto out;
 234
 235         /* Aggregate tx and rx stats from each queue */
 236         for (index = 0; index < vif->num_queues; ++index) {
 237                 queue = &vif->queues[index];
 238                 rx_bytes += queue->stats.rx_bytes;
 239                 rx_packets += queue->stats.rx_packets;
 240                 tx_bytes += queue->stats.tx_bytes;
 241                 tx_packets += queue->stats.tx_packets;
 242         }
 243
 244 out:
 245         spin_unlock(&vif->lock);
 246
 247         vif->dev->stats.rx_bytes = rx_bytes;
 248         vif->dev->stats.rx_packets = rx_packets;
 249         vif->dev->stats.tx_bytes = tx_bytes;
 250         vif->dev->stats.tx_packets = tx_packets;
 251
 252         return &vif->dev->stats;
 253 }
 254
 255 static void xenvif_up(struct xenvif *vif)
 256 {
 257         struct xenvif_queue *queue = NULL;
 258         unsigned int num_queues = vif->num_queues;
 259         unsigned int queue_index;
 260
 261         for (queue_index = 0; queue_index < num_queues; ++queue_index) {
 262                 queue = &vif->queues[queue_index];
 263                 napi_enable(&queue->napi);
 264                 enable_irq(queue->tx_irq);
 265                 if (queue->tx_irq != queue->rx_irq)
 266                         enable_irq(queue->rx_irq);
 267                 xenvif_napi_schedule_or_enable_events(queue);
 268         }
 269 }
 270
 271 static void xenvif_down(struct xenvif *vif)
 272 {
 273         struct xenvif_queue *queue = NULL;
 274         unsigned int num_queues = vif->num_queues;
 275         unsigned int queue_index;
 276
 277         for (queue_index = 0; queue_index < num_queues; ++queue_index) {
 278                 queue = &vif->queues[queue_index];
 279                 disable_irq(queue->tx_irq);
 280                 if (queue->tx_irq != queue->rx_irq)
 281                         disable_irq(queue->rx_irq);
 282                 napi_disable(&queue->napi);
 283                 del_timer_sync(&queue->credit_timeout);
 284         }
 285 }
 286
 287 static int xenvif_open(struct net_device *dev)
 288 {
 289         struct xenvif *vif = netdev_priv(dev);
 290         if (test_bit(VIF_STATUS_CONNECTED, &vif->status))
 291                 xenvif_up(vif);
 292         netif_tx_start_all_queues(dev);
 293         return 0;
 294 }
 295
 296 static int xenvif_close(struct net_device *dev)
 297 {
 298         struct xenvif *vif = netdev_priv(dev);
 299         if (test_bit(VIF_STATUS_CONNECTED, &vif->status))
 300                 xenvif_down(vif);
 301         netif_tx_stop_all_queues(dev);
 302         return 0;
 303 }
 304
 305 static int xenvif_change_mtu(struct net_device *dev, int mtu)
 306 {
 307         struct xenvif *vif = netdev_priv(dev);
 308         int max = vif->can_sg ? ETH_MAX_MTU - VLAN_ETH_HLEN : ETH_DATA_LEN;
 309
 310         if (mtu > max)
 311                 return -EINVAL;
 312         dev->mtu = mtu;
 313         return 0;
 314 }
 315
 316 static netdev_features_t xenvif_fix_features(struct net_device *dev,
 317         netdev_features_t features)
 318 {
 319         struct xenvif *vif = netdev_priv(dev);
 320
 321         if (!vif->can_sg)
 322                 features &= ~NETIF_F_SG;
 323         if (~(vif->gso_mask) & GSO_BIT(TCPV4))
 324                 features &= ~NETIF_F_TSO;
 325         if (~(vif->gso_mask) & GSO_BIT(TCPV6))
 326                 features &= ~NETIF_F_TSO6;
 327         if (!vif->ip_csum)
 328                 features &= ~NETIF_F_IP_CSUM;
 329         if (!vif->ipv6_csum)
 330                 features &= ~NETIF_F_IPV6_CSUM;
 331
 332         return features;
 333 }
 334
 335 static const struct xenvif_stat {
 336         char name[ETH_GSTRING_LEN];
 337         u16 offset;
 338 } xenvif_stats[] = {
 339         {
 340                 "rx_gso_checksum_fixup",
 341                 offsetof(struct xenvif_stats, rx_gso_checksum_fixup)
 342         },
 343         /* If (sent != success + fail), there are probably packets never
 344          * freed up properly!
 345          */
 346         {
 347                 "tx_zerocopy_sent",
 348                 offsetof(struct xenvif_stats, tx_zerocopy_sent),
 349         },
 350         {
 351                 "tx_zerocopy_success",
 352                 offsetof(struct xenvif_stats, tx_zerocopy_success),
 353         },
 354         {
 355                 "tx_zerocopy_fail",
 356                 offsetof(struct xenvif_stats, tx_zerocopy_fail)
 357         },
 358         /* Number of packets exceeding MAX_SKB_FRAG slots. You should use
 359          * a guest with the same MAX_SKB_FRAG
 360          */
 361         {
 362                 "tx_frag_overflow",
 363                 offsetof(struct xenvif_stats, tx_frag_overflow)
 364         },
 365 };
 366
 367 static int xenvif_get_sset_count(struct net_device *dev, int string_set)
 368 {
 369         switch (string_set) {
 370         case ETH_SS_STATS:
 371                 return ARRAY_SIZE(xenvif_stats);
 372         default:
 373                 return -EINVAL;
 374         }
 375 }
 376
 377 static void xenvif_get_ethtool_stats(struct net_device *dev,
 378                                      struct ethtool_stats *stats, u64 * data)
 379 {
 380         struct xenvif *vif = netdev_priv(dev);
 381         unsigned int num_queues = vif->num_queues;
 382         int i;
 383         unsigned int queue_index;
 384
 385         for (i = 0; i < ARRAY_SIZE(xenvif_stats); i++) {
 386                 unsigned long accum = 0;
 387                 for (queue_index = 0; queue_index < num_queues; ++queue_index) {
 388                         void *vif_stats = &vif->queues[queue_index].stats;
 389                         accum += *(unsigned long *)(vif_stats + xenvif_stats[i].offset);
 390                 }
 391                 data[i] = accum;
 392         }
 393 }
 394
 395 static void xenvif_get_strings(struct net_device *dev, u32 stringset, u8 * data)
 396 {
 397         int i;
 398
 399         switch (stringset) {
 400         case ETH_SS_STATS:
 401                 for (i = 0; i < ARRAY_SIZE(xenvif_stats); i++)
 402                         memcpy(data + i * ETH_GSTRING_LEN,
 403                                xenvif_stats[i].name, ETH_GSTRING_LEN);
 404                 break;
 405         }
 406 }
 407
 408 static const struct ethtool_ops xenvif_ethtool_ops = {
 409         .get_link       = ethtool_op_get_link,
 410
 411         .get_sset_count = xenvif_get_sset_count,
 412         .get_ethtool_stats = xenvif_get_ethtool_stats,
 413         .get_strings = xenvif_get_strings,
 414 };
 415
 416 static const struct net_device_ops xenvif_netdev_ops = {
 417         .ndo_select_queue = xenvif_select_queue,
 418         .ndo_start_xmit = xenvif_start_xmit,
 419         .ndo_get_stats  = xenvif_get_stats,
 420         .ndo_open       = xenvif_open,
 421         .ndo_stop       = xenvif_close,
 422         .ndo_change_mtu = xenvif_change_mtu,
 423         .ndo_fix_features = xenvif_fix_features,
 424         .ndo_set_mac_address = eth_mac_addr,
 425         .ndo_validate_addr   = eth_validate_addr,
 426 };
 427
 428 struct xenvif *xenvif_alloc(struct device *parent, domid_t domid,
 429                             unsigned int handle)
 430 {
 431         int err;
 432         struct net_device *dev;
 433         struct xenvif *vif;
 434         char name[IFNAMSIZ] = {};
 435
 436         snprintf(name, IFNAMSIZ - 1, "vif%u.%u", domid, handle);
 437         /* Allocate a netdev with the max. supported number of queues.
 438          * When the guest selects the desired number, it will be updated
 439          * via netif_set_real_num_*_queues().
 440          */
 441         dev = alloc_netdev_mq(sizeof(struct xenvif), name, NET_NAME_UNKNOWN,
 442                               ether_setup, xenvif_max_queues);
 443         if (dev == NULL) {
 444                 pr_warn("Could not allocate netdev for %s\n", name);
 445                 return ERR_PTR(-ENOMEM);
 446         }
 447
 448         SET_NETDEV_DEV(dev, parent);
 449
 450         vif = netdev_priv(dev);
 451
 452         vif->domid  = domid;
 453         vif->handle = handle;
 454         vif->can_sg = 1;
 455         vif->ip_csum = 1;
 456         vif->dev = dev;
 457         vif->disabled = false;
 458         vif->drain_timeout = msecs_to_jiffies(rx_drain_timeout_msecs);
 459         vif->stall_timeout = msecs_to_jiffies(rx_stall_timeout_msecs);
 460
 461         /* Start out with no queues. */
 462         vif->queues = NULL;
 463         vif->num_queues = 0;
 464
 465         spin_lock_init(&vif->lock);
 466         INIT_LIST_HEAD(&vif->fe_mcast_addr);
 467
 468         dev->netdev_ops = &xenvif_netdev_ops;
 469         dev->hw_features = NETIF_F_SG |
 470                 NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM |
 471                 NETIF_F_TSO | NETIF_F_TSO6 | NETIF_F_FRAGLIST;
 472         dev->features = dev->hw_features | NETIF_F_RXCSUM;
 473         dev->ethtool_ops = &xenvif_ethtool_ops;
 474
 475         dev->tx_queue_len = XENVIF_QUEUE_LENGTH;
 476
 477         dev->min_mtu = 0;
 478         dev->max_mtu = ETH_MAX_MTU - VLAN_ETH_HLEN;
 479
 480         /*
 481          * Initialise a dummy MAC address. We choose the numerically
 482          * largest non-broadcast address to prevent the address getting
 483          * stolen by an Ethernet bridge for STP purposes.
 484          * (FE:FF:FF:FF:FF:FF)
 485          */
 486         eth_broadcast_addr(dev->dev_addr);
 487         dev->dev_addr[0] &= ~0x01;
 488
 489         netif_carrier_off(dev);
 490
 491         err = register_netdev(dev);
 492         if (err) {
 493                 netdev_warn(dev, "Could not register device: err=%d\n", err);
 494                 free_netdev(dev);
 495                 return ERR_PTR(err);
 496         }
 497
 498         netdev_dbg(dev, "Successfully created xenvif\n");
 499
 500         __module_get(THIS_MODULE);
 501
 502         return vif;
 503 }
 504
 505 int xenvif_init_queue(struct xenvif_queue *queue)
 506 {
 507         int err, i;
 508
 509         queue->credit_bytes = queue->remaining_credit = ~0UL;
 510         queue->credit_usec  = 0UL;
 511         init_timer(&queue->credit_timeout);
 512         queue->credit_timeout.function = xenvif_tx_credit_callback;
 513         queue->credit_window_start = get_jiffies_64();
 514
 515         queue->rx_queue_max = XENVIF_RX_QUEUE_BYTES;
 516
 517         skb_queue_head_init(&queue->rx_queue);
 518         skb_queue_head_init(&queue->tx_queue);
 519
 520         queue->pending_cons = 0;
 521         queue->pending_prod = MAX_PENDING_REQS;
 522         for (i = 0; i < MAX_PENDING_REQS; ++i)
 523                 queue->pending_ring[i] = i;
 524
 525         spin_lock_init(&queue->callback_lock);
 526         spin_lock_init(&queue->response_lock);
 527
 528         /* If ballooning is disabled, this will consume real memory, so you
 529          * better enable it. The long term solution would be to use just a
 530          * bunch of valid page descriptors, without dependency on ballooning
 531          */
 532         err = gnttab_alloc_pages(MAX_PENDING_REQS,
 533                                  queue->mmap_pages);
 534         if (err) {
 535                 netdev_err(queue->vif->dev, "Could not reserve mmap_pages\n");
 536                 return -ENOMEM;
 537         }
 538
 539         for (i = 0; i < MAX_PENDING_REQS; i++) {
 540                 queue->pending_tx_info[i].callback_struct = (struct ubuf_info)
 541                         { .callback = xenvif_zerocopy_callback,
 542                           .ctx = NULL,
 543                           .desc = i };
 544                 queue->grant_tx_handle[i] = NETBACK_INVALID_HANDLE;
 545         }
 546
 547         return 0;
 548 }
 549
 550 void xenvif_carrier_on(struct xenvif *vif)
 551 {
 552         rtnl_lock();
 553         if (!vif->can_sg && vif->dev->mtu > ETH_DATA_LEN)
 554                 dev_set_mtu(vif->dev, ETH_DATA_LEN);
 555         netdev_update_features(vif->dev);
 556         set_bit(VIF_STATUS_CONNECTED, &vif->status);
 557         if (netif_running(vif->dev))
 558                 xenvif_up(vif);
 559         rtnl_unlock();
 560 }
 561
 562 int xenvif_connect_ctrl(struct xenvif *vif, grant_ref_t ring_ref,
 563                         unsigned int evtchn)
 564 {
 565         struct net_device *dev = vif->dev;
 566         void *addr;
 567         struct xen_netif_ctrl_sring *shared;
 568         int err;
 569
 570         err = xenbus_map_ring_valloc(xenvif_to_xenbus_device(vif),
 571                                      &ring_ref, 1, &addr);
 572         if (err)
 573                 goto err;
 574
 575         shared = (struct xen_netif_ctrl_sring *)addr;
 576         BACK_RING_INIT(&vif->ctrl, shared, XEN_PAGE_SIZE);
 577
 578         err = bind_interdomain_evtchn_to_irq(vif->domid, evtchn);
 579         if (err < 0)
 580                 goto err_unmap;
 581
 582         vif->ctrl_irq = err;
 583
 584         xenvif_init_hash(vif);
 585
 586         err = request_threaded_irq(vif->ctrl_irq, NULL, xenvif_ctrl_irq_fn,
 587                                    IRQF_ONESHOT, "xen-netback-ctrl", vif);
 588         if (err) {
 589                 pr_warn("Could not setup irq handler for %s\n", dev->name);
 590                 goto err_deinit;
 591         }
 592
 593         return 0;
 594
 595 err_deinit:
 596         xenvif_deinit_hash(vif);
 597         unbind_from_irqhandler(vif->ctrl_irq, vif);
 598         vif->ctrl_irq = 0;
 599
 600 err_unmap:
 601         xenbus_unmap_ring_vfree(xenvif_to_xenbus_device(vif),
 602                                 vif->ctrl.sring);
 603         vif->ctrl.sring = NULL;
 604
 605 err:
 606         return err;
 607 }
 608
 609 int xenvif_connect_data(struct xenvif_queue *queue,
 610                         unsigned long tx_ring_ref,
 611                         unsigned long rx_ring_ref,
 612                         unsigned int tx_evtchn,
 613                         unsigned int rx_evtchn)
 614 {
 615         struct task_struct *task;
 616         int err = -ENOMEM;
 617
 618         BUG_ON(queue->tx_irq);
 619         BUG_ON(queue->task);
 620         BUG_ON(queue->dealloc_task);
 621
 622         err = xenvif_map_frontend_data_rings(queue, tx_ring_ref,
 623                                              rx_ring_ref);
 624         if (err < 0)
 625                 goto err;
 626
 627         init_waitqueue_head(&queue->wq);
 628         init_waitqueue_head(&queue->dealloc_wq);
 629         atomic_set(&queue->inflight_packets, 0);
 630
 631         netif_napi_add(queue->vif->dev, &queue->napi, xenvif_poll,
 632                         XENVIF_NAPI_WEIGHT);
 633
 634         if (tx_evtchn == rx_evtchn) {
 635                 /* feature-split-event-channels == 0 */
 636                 err = bind_interdomain_evtchn_to_irqhandler(
 637                         queue->vif->domid, tx_evtchn, xenvif_interrupt, 0,
 638                         queue->name, queue);
 639                 if (err < 0)
 640                         goto err_unmap;
 641                 queue->tx_irq = queue->rx_irq = err;
 642                 disable_irq(queue->tx_irq);
 643         } else {
 644                 /* feature-split-event-channels == 1 */
 645                 snprintf(queue->tx_irq_name, sizeof(queue->tx_irq_name),
 646                          "%s-tx", queue->name);
 647                 err = bind_interdomain_evtchn_to_irqhandler(
 648                         queue->vif->domid, tx_evtchn, xenvif_tx_interrupt, 0,
 649                         queue->tx_irq_name, queue);
 650                 if (err < 0)
 651                         goto err_unmap;
 652                 queue->tx_irq = err;
 653                 disable_irq(queue->tx_irq);
 654
 655                 snprintf(queue->rx_irq_name, sizeof(queue->rx_irq_name),
 656                          "%s-rx", queue->name);
 657                 err = bind_interdomain_evtchn_to_irqhandler(
 658                         queue->vif->domid, rx_evtchn, xenvif_rx_interrupt, 0,
 659                         queue->rx_irq_name, queue);
 660                 if (err < 0)
 661                         goto err_tx_unbind;
 662                 queue->rx_irq = err;
 663                 disable_irq(queue->rx_irq);
 664         }
 665
 666         queue->stalled = true;
 667
 668         task = kthread_create(xenvif_kthread_guest_rx,
 669                               (void *)queue, "%s-guest-rx", queue->name);
 670         if (IS_ERR(task)) {
 671                 pr_warn("Could not allocate kthread for %s\n", queue->name);
 672                 err = PTR_ERR(task);
 673                 goto err_rx_unbind;
 674         }
 675         queue->task = task;
 676         get_task_struct(task);
 677
 678         task = kthread_create(xenvif_dealloc_kthread,
 679                               (void *)queue, "%s-dealloc", queue->name);
 680         if (IS_ERR(task)) {
 681                 pr_warn("Could not allocate kthread for %s\n", queue->name);
 682                 err = PTR_ERR(task);
 683                 goto err_rx_unbind;
 684         }
 685         queue->dealloc_task = task;
 686
 687         wake_up_process(queue->task);
 688         wake_up_process(queue->dealloc_task);
 689
 690         return 0;
 691
 692 err_rx_unbind:
 693         unbind_from_irqhandler(queue->rx_irq, queue);
 694         queue->rx_irq = 0;
 695 err_tx_unbind:
 696         unbind_from_irqhandler(queue->tx_irq, queue);
 697         queue->tx_irq = 0;
 698 err_unmap:
 699         xenvif_unmap_frontend_data_rings(queue);
 700         netif_napi_del(&queue->napi);
 701 err:
 702         module_put(THIS_MODULE);
 703         return err;
 704 }
 705
 706 void xenvif_carrier_off(struct xenvif *vif)
 707 {
 708         struct net_device *dev = vif->dev;
 709
 710         rtnl_lock();
 711         if (test_and_clear_bit(VIF_STATUS_CONNECTED, &vif->status)) {
 712                 netif_carrier_off(dev); /* discard queued packets */
 713                 if (netif_running(dev))
 714                         xenvif_down(vif);
 715         }
 716         rtnl_unlock();
 717 }
 718
 719 void xenvif_disconnect_data(struct xenvif *vif)
 720 {
 721         struct xenvif_queue *queue = NULL;
 722         unsigned int num_queues = vif->num_queues;
 723         unsigned int queue_index;
 724
 725         xenvif_carrier_off(vif);
 726
 727         for (queue_index = 0; queue_index < num_queues; ++queue_index) {
 728                 queue = &vif->queues[queue_index];
 729
 730                 netif_napi_del(&queue->napi);
 731
 732                 if (queue->task) {
 733                         kthread_stop(queue->task);
 734                         put_task_struct(queue->task);
 735                         queue->task = NULL;
 736                 }
 737
 738                 if (queue->dealloc_task) {
 739                         kthread_stop(queue->dealloc_task);
 740                         queue->dealloc_task = NULL;
 741                 }
 742
 743                 if (queue->tx_irq) {
 744                         if (queue->tx_irq == queue->rx_irq)
 745                                 unbind_from_irqhandler(queue->tx_irq, queue);
 746                         else {
 747                                 unbind_from_irqhandler(queue->tx_irq, queue);
 748                                 unbind_from_irqhandler(queue->rx_irq, queue);
 749                         }
 750                         queue->tx_irq = 0;
 751                 }
 752
 753                 xenvif_unmap_frontend_data_rings(queue);
 754         }
 755
 756         xenvif_mcast_addr_list_free(vif);
 757 }
 758
 759 void xenvif_disconnect_ctrl(struct xenvif *vif)
 760 {
 761         if (vif->ctrl_irq) {
 762                 xenvif_deinit_hash(vif);
 763                 unbind_from_irqhandler(vif->ctrl_irq, vif);
 764                 vif->ctrl_irq = 0;
 765         }
 766
 767         if (vif->ctrl.sring) {
 768                 xenbus_unmap_ring_vfree(xenvif_to_xenbus_device(vif),
 769                                         vif->ctrl.sring);
 770                 vif->ctrl.sring = NULL;
 771         }
 772 }
 773
 774 /* Reverse the relevant parts of xenvif_init_queue().
 775  * Used for queue teardown from xenvif_free(), and on the
 776  * error handling paths in xenbus.c:connect().
 777  */
 778 void xenvif_deinit_queue(struct xenvif_queue *queue)
 779 {
 780         gnttab_free_pages(MAX_PENDING_REQS, queue->mmap_pages);
 781 }
 782
 783 void xenvif_free(struct xenvif *vif)
 784 {
 785         struct xenvif_queue *queues = vif->queues;
 786         unsigned int num_queues = vif->num_queues;
 787         unsigned int queue_index;
 788
 789         unregister_netdev(vif->dev);
 790         free_netdev(vif->dev);
 791
 792         for (queue_index = 0; queue_index < num_queues; ++queue_index)
 793                 xenvif_deinit_queue(&queues[queue_index]);
 794         vfree(queues);
 795
 796         module_put(THIS_MODULE);
 797 }