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