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/ethtool.h> 35 #include <linux/rtnetlink.h> 36 #include <linux/if_vlan.h> 37 #include <linux/vmalloc.h> 38 39 #include <xen/events.h> 40 #include <asm/xen/hypercall.h> 41 #include <xen/balloon.h> 42 43 #define XENVIF_QUEUE_LENGTH 32 44 #define XENVIF_NAPI_WEIGHT 64 45 46 static inline void xenvif_stop_queue(struct xenvif_queue *queue) 47 { 48 struct net_device *dev = queue->vif->dev; 49 50 if (!queue->vif->can_queue) 51 return; 52 53 netif_tx_stop_queue(netdev_get_tx_queue(dev, queue->id)); 54 } 55 56 int xenvif_schedulable(struct xenvif *vif) 57 { 58 return netif_running(vif->dev) && netif_carrier_ok(vif->dev); 59 } 60 61 static irqreturn_t xenvif_tx_interrupt(int irq, void *dev_id) 62 { 63 struct xenvif_queue *queue = dev_id; 64 65 if (RING_HAS_UNCONSUMED_REQUESTS(&queue->tx)) 66 napi_schedule(&queue->napi); 67 68 return IRQ_HANDLED; 69 } 70 71 int xenvif_poll(struct napi_struct *napi, int budget) 72 { 73 struct xenvif_queue *queue = 74 container_of(napi, struct xenvif_queue, napi); 75 int work_done; 76 77 /* This vif is rogue, we pretend we've there is nothing to do 78 * for this vif to deschedule it from NAPI. But this interface 79 * will be turned off in thread context later. 80 */ 81 if (unlikely(queue->vif->disabled)) { 82 napi_complete(napi); 83 return 0; 84 } 85 86 work_done = xenvif_tx_action(queue, budget); 87 88 if (work_done < budget) { 89 napi_complete(napi); 90 xenvif_napi_schedule_or_enable_events(queue); 91 } 92 93 return work_done; 94 } 95 96 static irqreturn_t xenvif_rx_interrupt(int irq, void *dev_id) 97 { 98 struct xenvif_queue *queue = dev_id; 99 100 xenvif_kick_thread(queue); 101 102 return IRQ_HANDLED; 103 } 104 105 static irqreturn_t xenvif_interrupt(int irq, void *dev_id) 106 { 107 xenvif_tx_interrupt(irq, dev_id); 108 xenvif_rx_interrupt(irq, dev_id); 109 110 return IRQ_HANDLED; 111 } 112 113 int xenvif_queue_stopped(struct xenvif_queue *queue) 114 { 115 struct net_device *dev = queue->vif->dev; 116 unsigned int id = queue->id; 117 return netif_tx_queue_stopped(netdev_get_tx_queue(dev, id)); 118 } 119 120 void xenvif_wake_queue(struct xenvif_queue *queue) 121 { 122 struct net_device *dev = queue->vif->dev; 123 unsigned int id = queue->id; 124 netif_tx_wake_queue(netdev_get_tx_queue(dev, id)); 125 } 126 127 /* Callback to wake the queue and drain it on timeout */ 128 static void xenvif_wake_queue_callback(unsigned long data) 129 { 130 struct xenvif_queue *queue = (struct xenvif_queue *)data; 131 132 if (xenvif_queue_stopped(queue)) { 133 netdev_err(queue->vif->dev, "draining TX queue\n"); 134 queue->rx_queue_purge = true; 135 xenvif_kick_thread(queue); 136 xenvif_wake_queue(queue); 137 } 138 } 139 140 static u16 xenvif_select_queue(struct net_device *dev, struct sk_buff *skb, 141 void *accel_priv, select_queue_fallback_t fallback) 142 { 143 unsigned int num_queues = dev->real_num_tx_queues; 144 u32 hash; 145 u16 queue_index; 146 147 /* First, check if there is only one queue to optimise the 148 * single-queue or old frontend scenario. 149 */ 150 if (num_queues == 1) { 151 queue_index = 0; 152 } else { 153 /* Use skb_get_hash to obtain an L4 hash if available */ 154 hash = skb_get_hash(skb); 155 queue_index = hash % num_queues; 156 } 157 158 return queue_index; 159 } 160 161 static int xenvif_start_xmit(struct sk_buff *skb, struct net_device *dev) 162 { 163 struct xenvif *vif = netdev_priv(dev); 164 struct xenvif_queue *queue = NULL; 165 unsigned int num_queues = dev->real_num_tx_queues; 166 u16 index; 167 int min_slots_needed; 168 169 BUG_ON(skb->dev != dev); 170 171 /* Drop the packet if queues are not set up */ 172 if (num_queues < 1) 173 goto drop; 174 175 /* Obtain the queue to be used to transmit this packet */ 176 index = skb_get_queue_mapping(skb); 177 if (index >= num_queues) { 178 pr_warn_ratelimited("Invalid queue %hu for packet on interface %s\n.", 179 index, vif->dev->name); 180 index %= num_queues; 181 } 182 queue = &vif->queues[index]; 183 184 /* Drop the packet if queue is not ready */ 185 if (queue->task == NULL || 186 queue->dealloc_task == NULL || 187 !xenvif_schedulable(vif)) 188 goto drop; 189 190 /* At best we'll need one slot for the header and one for each 191 * frag. 192 */ 193 min_slots_needed = 1 + skb_shinfo(skb)->nr_frags; 194 195 /* If the skb is GSO then we'll also need an extra slot for the 196 * metadata. 197 */ 198 if (skb_is_gso(skb)) 199 min_slots_needed++; 200 201 /* If the skb can't possibly fit in the remaining slots 202 * then turn off the queue to give the ring a chance to 203 * drain. 204 */ 205 if (!xenvif_rx_ring_slots_available(queue, min_slots_needed)) { 206 queue->wake_queue.function = xenvif_wake_queue_callback; 207 queue->wake_queue.data = (unsigned long)queue; 208 xenvif_stop_queue(queue); 209 mod_timer(&queue->wake_queue, 210 jiffies + rx_drain_timeout_jiffies); 211 } 212 213 skb_queue_tail(&queue->rx_queue, skb); 214 xenvif_kick_thread(queue); 215 216 return NETDEV_TX_OK; 217 218 drop: 219 vif->dev->stats.tx_dropped++; 220 dev_kfree_skb(skb); 221 return NETDEV_TX_OK; 222 } 223 224 static struct net_device_stats *xenvif_get_stats(struct net_device *dev) 225 { 226 struct xenvif *vif = netdev_priv(dev); 227 struct xenvif_queue *queue = NULL; 228 unsigned int num_queues = dev->real_num_tx_queues; 229 unsigned long rx_bytes = 0; 230 unsigned long rx_packets = 0; 231 unsigned long tx_bytes = 0; 232 unsigned long tx_packets = 0; 233 unsigned int index; 234 235 if (vif->queues == NULL) 236 goto out; 237 238 /* Aggregate tx and rx stats from each queue */ 239 for (index = 0; index < num_queues; ++index) { 240 queue = &vif->queues[index]; 241 rx_bytes += queue->stats.rx_bytes; 242 rx_packets += queue->stats.rx_packets; 243 tx_bytes += queue->stats.tx_bytes; 244 tx_packets += queue->stats.tx_packets; 245 } 246 247 out: 248 vif->dev->stats.rx_bytes = rx_bytes; 249 vif->dev->stats.rx_packets = rx_packets; 250 vif->dev->stats.tx_bytes = tx_bytes; 251 vif->dev->stats.tx_packets = tx_packets; 252 253 return &vif->dev->stats; 254 } 255 256 static void xenvif_up(struct xenvif *vif) 257 { 258 struct xenvif_queue *queue = NULL; 259 unsigned int num_queues = vif->dev->real_num_tx_queues; 260 unsigned int queue_index; 261 262 for (queue_index = 0; queue_index < num_queues; ++queue_index) { 263 queue = &vif->queues[queue_index]; 264 napi_enable(&queue->napi); 265 enable_irq(queue->tx_irq); 266 if (queue->tx_irq != queue->rx_irq) 267 enable_irq(queue->rx_irq); 268 xenvif_napi_schedule_or_enable_events(queue); 269 } 270 } 271 272 static void xenvif_down(struct xenvif *vif) 273 { 274 struct xenvif_queue *queue = NULL; 275 unsigned int num_queues = vif->dev->real_num_tx_queues; 276 unsigned int queue_index; 277 278 for (queue_index = 0; queue_index < num_queues; ++queue_index) { 279 queue = &vif->queues[queue_index]; 280 napi_disable(&queue->napi); 281 disable_irq(queue->tx_irq); 282 if (queue->tx_irq != queue->rx_irq) 283 disable_irq(queue->rx_irq); 284 del_timer_sync(&queue->credit_timeout); 285 } 286 } 287 288 static int xenvif_open(struct net_device *dev) 289 { 290 struct xenvif *vif = netdev_priv(dev); 291 if (netif_carrier_ok(dev)) 292 xenvif_up(vif); 293 netif_tx_start_all_queues(dev); 294 return 0; 295 } 296 297 static int xenvif_close(struct net_device *dev) 298 { 299 struct xenvif *vif = netdev_priv(dev); 300 if (netif_carrier_ok(dev)) 301 xenvif_down(vif); 302 netif_tx_stop_all_queues(dev); 303 return 0; 304 } 305 306 static int xenvif_change_mtu(struct net_device *dev, int mtu) 307 { 308 struct xenvif *vif = netdev_priv(dev); 309 int max = vif->can_sg ? 65535 - VLAN_ETH_HLEN : ETH_DATA_LEN; 310 311 if (mtu > max) 312 return -EINVAL; 313 dev->mtu = mtu; 314 return 0; 315 } 316 317 static netdev_features_t xenvif_fix_features(struct net_device *dev, 318 netdev_features_t features) 319 { 320 struct xenvif *vif = netdev_priv(dev); 321 322 if (!vif->can_sg) 323 features &= ~NETIF_F_SG; 324 if (~(vif->gso_mask | vif->gso_prefix_mask) & GSO_BIT(TCPV4)) 325 features &= ~NETIF_F_TSO; 326 if (~(vif->gso_mask | vif->gso_prefix_mask) & GSO_BIT(TCPV6)) 327 features &= ~NETIF_F_TSO6; 328 if (!vif->ip_csum) 329 features &= ~NETIF_F_IP_CSUM; 330 if (!vif->ipv6_csum) 331 features &= ~NETIF_F_IPV6_CSUM; 332 333 return features; 334 } 335 336 static const struct xenvif_stat { 337 char name[ETH_GSTRING_LEN]; 338 u16 offset; 339 } xenvif_stats[] = { 340 { 341 "rx_gso_checksum_fixup", 342 offsetof(struct xenvif_stats, rx_gso_checksum_fixup) 343 }, 344 /* If (sent != success + fail), there are probably packets never 345 * freed up properly! 346 */ 347 { 348 "tx_zerocopy_sent", 349 offsetof(struct xenvif_stats, tx_zerocopy_sent), 350 }, 351 { 352 "tx_zerocopy_success", 353 offsetof(struct xenvif_stats, tx_zerocopy_success), 354 }, 355 { 356 "tx_zerocopy_fail", 357 offsetof(struct xenvif_stats, tx_zerocopy_fail) 358 }, 359 /* Number of packets exceeding MAX_SKB_FRAG slots. You should use 360 * a guest with the same MAX_SKB_FRAG 361 */ 362 { 363 "tx_frag_overflow", 364 offsetof(struct xenvif_stats, tx_frag_overflow) 365 }, 366 }; 367 368 static int xenvif_get_sset_count(struct net_device *dev, int string_set) 369 { 370 switch (string_set) { 371 case ETH_SS_STATS: 372 return ARRAY_SIZE(xenvif_stats); 373 default: 374 return -EINVAL; 375 } 376 } 377 378 static void xenvif_get_ethtool_stats(struct net_device *dev, 379 struct ethtool_stats *stats, u64 * data) 380 { 381 struct xenvif *vif = netdev_priv(dev); 382 unsigned int num_queues = dev->real_num_tx_queues; 383 int i; 384 unsigned int queue_index; 385 struct xenvif_stats *vif_stats; 386 387 for (i = 0; i < ARRAY_SIZE(xenvif_stats); i++) { 388 unsigned long accum = 0; 389 for (queue_index = 0; queue_index < num_queues; ++queue_index) { 390 vif_stats = &vif->queues[queue_index].stats; 391 accum += *(unsigned long *)(vif_stats + xenvif_stats[i].offset); 392 } 393 data[i] = accum; 394 } 395 } 396 397 static void xenvif_get_strings(struct net_device *dev, u32 stringset, u8 * data) 398 { 399 int i; 400 401 switch (stringset) { 402 case ETH_SS_STATS: 403 for (i = 0; i < ARRAY_SIZE(xenvif_stats); i++) 404 memcpy(data + i * ETH_GSTRING_LEN, 405 xenvif_stats[i].name, ETH_GSTRING_LEN); 406 break; 407 } 408 } 409 410 static const struct ethtool_ops xenvif_ethtool_ops = { 411 .get_link = ethtool_op_get_link, 412 413 .get_sset_count = xenvif_get_sset_count, 414 .get_ethtool_stats = xenvif_get_ethtool_stats, 415 .get_strings = xenvif_get_strings, 416 }; 417 418 static const struct net_device_ops xenvif_netdev_ops = { 419 .ndo_start_xmit = xenvif_start_xmit, 420 .ndo_get_stats = xenvif_get_stats, 421 .ndo_open = xenvif_open, 422 .ndo_stop = xenvif_close, 423 .ndo_change_mtu = xenvif_change_mtu, 424 .ndo_fix_features = xenvif_fix_features, 425 .ndo_set_mac_address = eth_mac_addr, 426 .ndo_validate_addr = eth_validate_addr, 427 .ndo_select_queue = xenvif_select_queue, 428 }; 429 430 struct xenvif *xenvif_alloc(struct device *parent, domid_t domid, 431 unsigned int handle) 432 { 433 int err; 434 struct net_device *dev; 435 struct xenvif *vif; 436 char name[IFNAMSIZ] = {}; 437 438 snprintf(name, IFNAMSIZ - 1, "vif%u.%u", domid, handle); 439 /* Allocate a netdev with the max. supported number of queues. 440 * When the guest selects the desired number, it will be updated 441 * via netif_set_real_num_tx_queues(). 442 */ 443 dev = alloc_netdev_mq(sizeof(struct xenvif), name, ether_setup, 444 xenvif_max_queues); 445 if (dev == NULL) { 446 pr_warn("Could not allocate netdev for %s\n", name); 447 return ERR_PTR(-ENOMEM); 448 } 449 450 SET_NETDEV_DEV(dev, parent); 451 452 vif = netdev_priv(dev); 453 454 vif->domid = domid; 455 vif->handle = handle; 456 vif->can_sg = 1; 457 vif->ip_csum = 1; 458 vif->dev = dev; 459 vif->disabled = false; 460 461 /* Start out with no queues. The call below does not require 462 * rtnl_lock() as it happens before register_netdev(). 463 */ 464 vif->queues = NULL; 465 netif_set_real_num_tx_queues(dev, 0); 466 467 dev->netdev_ops = &xenvif_netdev_ops; 468 dev->hw_features = NETIF_F_SG | 469 NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM | 470 NETIF_F_TSO | NETIF_F_TSO6; 471 dev->features = dev->hw_features | NETIF_F_RXCSUM; 472 dev->ethtool_ops = &xenvif_ethtool_ops; 473 474 dev->tx_queue_len = XENVIF_QUEUE_LENGTH; 475 476 /* 477 * Initialise a dummy MAC address. We choose the numerically 478 * largest non-broadcast address to prevent the address getting 479 * stolen by an Ethernet bridge for STP purposes. 480 * (FE:FF:FF:FF:FF:FF) 481 */ 482 memset(dev->dev_addr, 0xFF, ETH_ALEN); 483 dev->dev_addr[0] &= ~0x01; 484 485 netif_carrier_off(dev); 486 487 err = register_netdev(dev); 488 if (err) { 489 netdev_warn(dev, "Could not register device: err=%d\n", err); 490 free_netdev(dev); 491 return ERR_PTR(err); 492 } 493 494 netdev_dbg(dev, "Successfully created xenvif\n"); 495 496 __module_get(THIS_MODULE); 497 498 return vif; 499 } 500 501 int xenvif_init_queue(struct xenvif_queue *queue) 502 { 503 int err, i; 504 505 queue->credit_bytes = queue->remaining_credit = ~0UL; 506 queue->credit_usec = 0UL; 507 init_timer(&queue->credit_timeout); 508 queue->credit_window_start = get_jiffies_64(); 509 510 skb_queue_head_init(&queue->rx_queue); 511 skb_queue_head_init(&queue->tx_queue); 512 513 queue->pending_cons = 0; 514 queue->pending_prod = MAX_PENDING_REQS; 515 for (i = 0; i < MAX_PENDING_REQS; ++i) 516 queue->pending_ring[i] = i; 517 518 spin_lock_init(&queue->callback_lock); 519 spin_lock_init(&queue->response_lock); 520 521 /* If ballooning is disabled, this will consume real memory, so you 522 * better enable it. The long term solution would be to use just a 523 * bunch of valid page descriptors, without dependency on ballooning 524 */ 525 err = alloc_xenballooned_pages(MAX_PENDING_REQS, 526 queue->mmap_pages, 527 false); 528 if (err) { 529 netdev_err(queue->vif->dev, "Could not reserve mmap_pages\n"); 530 return -ENOMEM; 531 } 532 533 for (i = 0; i < MAX_PENDING_REQS; i++) { 534 queue->pending_tx_info[i].callback_struct = (struct ubuf_info) 535 { .callback = xenvif_zerocopy_callback, 536 .ctx = NULL, 537 .desc = i }; 538 queue->grant_tx_handle[i] = NETBACK_INVALID_HANDLE; 539 } 540 541 init_timer(&queue->wake_queue); 542 543 netif_napi_add(queue->vif->dev, &queue->napi, xenvif_poll, 544 XENVIF_NAPI_WEIGHT); 545 546 return 0; 547 } 548 549 void xenvif_carrier_on(struct xenvif *vif) 550 { 551 rtnl_lock(); 552 if (!vif->can_sg && vif->dev->mtu > ETH_DATA_LEN) 553 dev_set_mtu(vif->dev, ETH_DATA_LEN); 554 netdev_update_features(vif->dev); 555 netif_carrier_on(vif->dev); 556 if (netif_running(vif->dev)) 557 xenvif_up(vif); 558 rtnl_unlock(); 559 } 560 561 int xenvif_connect(struct xenvif_queue *queue, unsigned long tx_ring_ref, 562 unsigned long rx_ring_ref, unsigned int tx_evtchn, 563 unsigned int rx_evtchn) 564 { 565 struct task_struct *task; 566 int err = -ENOMEM; 567 568 BUG_ON(queue->tx_irq); 569 BUG_ON(queue->task); 570 BUG_ON(queue->dealloc_task); 571 572 err = xenvif_map_frontend_rings(queue, tx_ring_ref, rx_ring_ref); 573 if (err < 0) 574 goto err; 575 576 init_waitqueue_head(&queue->wq); 577 init_waitqueue_head(&queue->dealloc_wq); 578 579 if (tx_evtchn == rx_evtchn) { 580 /* feature-split-event-channels == 0 */ 581 err = bind_interdomain_evtchn_to_irqhandler( 582 queue->vif->domid, tx_evtchn, xenvif_interrupt, 0, 583 queue->name, queue); 584 if (err < 0) 585 goto err_unmap; 586 queue->tx_irq = queue->rx_irq = err; 587 disable_irq(queue->tx_irq); 588 } else { 589 /* feature-split-event-channels == 1 */ 590 snprintf(queue->tx_irq_name, sizeof(queue->tx_irq_name), 591 "%s-tx", queue->name); 592 err = bind_interdomain_evtchn_to_irqhandler( 593 queue->vif->domid, tx_evtchn, xenvif_tx_interrupt, 0, 594 queue->tx_irq_name, queue); 595 if (err < 0) 596 goto err_unmap; 597 queue->tx_irq = err; 598 disable_irq(queue->tx_irq); 599 600 snprintf(queue->rx_irq_name, sizeof(queue->rx_irq_name), 601 "%s-rx", queue->name); 602 err = bind_interdomain_evtchn_to_irqhandler( 603 queue->vif->domid, rx_evtchn, xenvif_rx_interrupt, 0, 604 queue->rx_irq_name, queue); 605 if (err < 0) 606 goto err_tx_unbind; 607 queue->rx_irq = err; 608 disable_irq(queue->rx_irq); 609 } 610 611 task = kthread_create(xenvif_kthread_guest_rx, 612 (void *)queue, "%s-guest-rx", queue->name); 613 if (IS_ERR(task)) { 614 pr_warn("Could not allocate kthread for %s\n", queue->name); 615 err = PTR_ERR(task); 616 goto err_rx_unbind; 617 } 618 queue->task = task; 619 620 task = kthread_create(xenvif_dealloc_kthread, 621 (void *)queue, "%s-dealloc", queue->name); 622 if (IS_ERR(task)) { 623 pr_warn("Could not allocate kthread for %s\n", queue->name); 624 err = PTR_ERR(task); 625 goto err_rx_unbind; 626 } 627 queue->dealloc_task = task; 628 629 wake_up_process(queue->task); 630 wake_up_process(queue->dealloc_task); 631 632 return 0; 633 634 err_rx_unbind: 635 unbind_from_irqhandler(queue->rx_irq, queue); 636 queue->rx_irq = 0; 637 err_tx_unbind: 638 unbind_from_irqhandler(queue->tx_irq, queue); 639 queue->tx_irq = 0; 640 err_unmap: 641 xenvif_unmap_frontend_rings(queue); 642 err: 643 module_put(THIS_MODULE); 644 return err; 645 } 646 647 void xenvif_carrier_off(struct xenvif *vif) 648 { 649 struct net_device *dev = vif->dev; 650 651 rtnl_lock(); 652 netif_carrier_off(dev); /* discard queued packets */ 653 if (netif_running(dev)) 654 xenvif_down(vif); 655 rtnl_unlock(); 656 } 657 658 static void xenvif_wait_unmap_timeout(struct xenvif_queue *queue, 659 unsigned int worst_case_skb_lifetime) 660 { 661 int i, unmap_timeout = 0; 662 663 for (i = 0; i < MAX_PENDING_REQS; ++i) { 664 if (queue->grant_tx_handle[i] != NETBACK_INVALID_HANDLE) { 665 unmap_timeout++; 666 schedule_timeout(msecs_to_jiffies(1000)); 667 if (unmap_timeout > worst_case_skb_lifetime && 668 net_ratelimit()) 669 netdev_err(queue->vif->dev, 670 "Page still granted! Index: %x\n", 671 i); 672 i = -1; 673 } 674 } 675 } 676 677 void xenvif_disconnect(struct xenvif *vif) 678 { 679 struct xenvif_queue *queue = NULL; 680 unsigned int num_queues = vif->dev->real_num_tx_queues; 681 unsigned int queue_index; 682 683 if (netif_carrier_ok(vif->dev)) 684 xenvif_carrier_off(vif); 685 686 for (queue_index = 0; queue_index < num_queues; ++queue_index) { 687 queue = &vif->queues[queue_index]; 688 689 if (queue->task) { 690 del_timer_sync(&queue->wake_queue); 691 kthread_stop(queue->task); 692 queue->task = NULL; 693 } 694 695 if (queue->dealloc_task) { 696 kthread_stop(queue->dealloc_task); 697 queue->dealloc_task = NULL; 698 } 699 700 if (queue->tx_irq) { 701 if (queue->tx_irq == queue->rx_irq) 702 unbind_from_irqhandler(queue->tx_irq, queue); 703 else { 704 unbind_from_irqhandler(queue->tx_irq, queue); 705 unbind_from_irqhandler(queue->rx_irq, queue); 706 } 707 queue->tx_irq = 0; 708 } 709 710 xenvif_unmap_frontend_rings(queue); 711 } 712 } 713 714 /* Reverse the relevant parts of xenvif_init_queue(). 715 * Used for queue teardown from xenvif_free(), and on the 716 * error handling paths in xenbus.c:connect(). 717 */ 718 void xenvif_deinit_queue(struct xenvif_queue *queue) 719 { 720 free_xenballooned_pages(MAX_PENDING_REQS, queue->mmap_pages); 721 netif_napi_del(&queue->napi); 722 } 723 724 void xenvif_free(struct xenvif *vif) 725 { 726 struct xenvif_queue *queue = NULL; 727 unsigned int num_queues = vif->dev->real_num_tx_queues; 728 unsigned int queue_index; 729 /* Here we want to avoid timeout messages if an skb can be legitimately 730 * stuck somewhere else. Realistically this could be an another vif's 731 * internal or QDisc queue. That another vif also has this 732 * rx_drain_timeout_msecs timeout, but the timer only ditches the 733 * internal queue. After that, the QDisc queue can put in worst case 734 * XEN_NETIF_RX_RING_SIZE / MAX_SKB_FRAGS skbs into that another vif's 735 * internal queue, so we need several rounds of such timeouts until we 736 * can be sure that no another vif should have skb's from us. We are 737 * not sending more skb's, so newly stuck packets are not interesting 738 * for us here. 739 */ 740 unsigned int worst_case_skb_lifetime = (rx_drain_timeout_msecs/1000) * 741 DIV_ROUND_UP(XENVIF_QUEUE_LENGTH, (XEN_NETIF_RX_RING_SIZE / MAX_SKB_FRAGS)); 742 743 unregister_netdev(vif->dev); 744 745 for (queue_index = 0; queue_index < num_queues; ++queue_index) { 746 queue = &vif->queues[queue_index]; 747 xenvif_wait_unmap_timeout(queue, worst_case_skb_lifetime); 748 xenvif_deinit_queue(queue); 749 } 750 751 /* Free the array of queues. The call below does not require 752 * rtnl_lock() because it happens after unregister_netdev(). 753 */ 754 netif_set_real_num_tx_queues(vif->dev, 0); 755 vfree(vif->queues); 756 vif->queues = NULL; 757 758 free_netdev(vif->dev); 759 760 module_put(THIS_MODULE); 761 } 762