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 SKBFL_ZEROCOPY_ENABLE 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)->flags |= SKBFL_ZEROCOPY_ENABLE; 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 bool xenvif_handle_tx_interrupt(struct xenvif_queue *queue) 81 { 82 bool rc; 83 84 rc = RING_HAS_UNCONSUMED_REQUESTS(&queue->tx); 85 if (rc) 86 napi_schedule(&queue->napi); 87 return rc; 88 } 89 90 static irqreturn_t xenvif_tx_interrupt(int irq, void *dev_id) 91 { 92 struct xenvif_queue *queue = dev_id; 93 int old; 94 95 old = atomic_fetch_or(NETBK_TX_EOI, &queue->eoi_pending); 96 WARN(old & NETBK_TX_EOI, "Interrupt while EOI pending\n"); 97 98 if (!xenvif_handle_tx_interrupt(queue)) { 99 atomic_andnot(NETBK_TX_EOI, &queue->eoi_pending); 100 xen_irq_lateeoi(irq, XEN_EOI_FLAG_SPURIOUS); 101 } 102 103 return IRQ_HANDLED; 104 } 105 106 static int xenvif_poll(struct napi_struct *napi, int budget) 107 { 108 struct xenvif_queue *queue = 109 container_of(napi, struct xenvif_queue, napi); 110 int work_done; 111 112 /* This vif is rogue, we pretend we've there is nothing to do 113 * for this vif to deschedule it from NAPI. But this interface 114 * will be turned off in thread context later. 115 */ 116 if (unlikely(queue->vif->disabled)) { 117 napi_complete(napi); 118 return 0; 119 } 120 121 work_done = xenvif_tx_action(queue, budget); 122 123 if (work_done < budget) { 124 napi_complete_done(napi, work_done); 125 /* If the queue is rate-limited, it shall be 126 * rescheduled in the timer callback. 127 */ 128 if (likely(!queue->rate_limited)) 129 xenvif_napi_schedule_or_enable_events(queue); 130 } 131 132 return work_done; 133 } 134 135 static bool xenvif_handle_rx_interrupt(struct xenvif_queue *queue) 136 { 137 bool rc; 138 139 rc = xenvif_have_rx_work(queue, false); 140 if (rc) 141 xenvif_kick_thread(queue); 142 return rc; 143 } 144 145 static irqreturn_t xenvif_rx_interrupt(int irq, void *dev_id) 146 { 147 struct xenvif_queue *queue = dev_id; 148 int old; 149 150 old = atomic_fetch_or(NETBK_RX_EOI, &queue->eoi_pending); 151 WARN(old & NETBK_RX_EOI, "Interrupt while EOI pending\n"); 152 153 if (!xenvif_handle_rx_interrupt(queue)) { 154 atomic_andnot(NETBK_RX_EOI, &queue->eoi_pending); 155 xen_irq_lateeoi(irq, XEN_EOI_FLAG_SPURIOUS); 156 } 157 158 return IRQ_HANDLED; 159 } 160 161 irqreturn_t xenvif_interrupt(int irq, void *dev_id) 162 { 163 struct xenvif_queue *queue = dev_id; 164 int old; 165 bool has_rx, has_tx; 166 167 old = atomic_fetch_or(NETBK_COMMON_EOI, &queue->eoi_pending); 168 WARN(old, "Interrupt while EOI pending\n"); 169 170 has_tx = xenvif_handle_tx_interrupt(queue); 171 has_rx = xenvif_handle_rx_interrupt(queue); 172 173 if (!has_rx && !has_tx) { 174 atomic_andnot(NETBK_COMMON_EOI, &queue->eoi_pending); 175 xen_irq_lateeoi(irq, XEN_EOI_FLAG_SPURIOUS); 176 } 177 178 return IRQ_HANDLED; 179 } 180 181 int xenvif_queue_stopped(struct xenvif_queue *queue) 182 { 183 struct net_device *dev = queue->vif->dev; 184 unsigned int id = queue->id; 185 return netif_tx_queue_stopped(netdev_get_tx_queue(dev, id)); 186 } 187 188 void xenvif_wake_queue(struct xenvif_queue *queue) 189 { 190 struct net_device *dev = queue->vif->dev; 191 unsigned int id = queue->id; 192 netif_tx_wake_queue(netdev_get_tx_queue(dev, id)); 193 } 194 195 static u16 xenvif_select_queue(struct net_device *dev, struct sk_buff *skb, 196 struct net_device *sb_dev) 197 { 198 struct xenvif *vif = netdev_priv(dev); 199 unsigned int size = vif->hash.size; 200 unsigned int num_queues; 201 202 /* If queues are not set up internally - always return 0 203 * as the packet going to be dropped anyway */ 204 num_queues = READ_ONCE(vif->num_queues); 205 if (num_queues < 1) 206 return 0; 207 208 if (vif->hash.alg == XEN_NETIF_CTRL_HASH_ALGORITHM_NONE) 209 return netdev_pick_tx(dev, skb, NULL) % 210 dev->real_num_tx_queues; 211 212 xenvif_set_skb_hash(vif, skb); 213 214 if (size == 0) 215 return skb_get_hash_raw(skb) % dev->real_num_tx_queues; 216 217 return vif->hash.mapping[vif->hash.mapping_sel] 218 [skb_get_hash_raw(skb) % size]; 219 } 220 221 static netdev_tx_t 222 xenvif_start_xmit(struct sk_buff *skb, struct net_device *dev) 223 { 224 struct xenvif *vif = netdev_priv(dev); 225 struct xenvif_queue *queue = NULL; 226 unsigned int num_queues; 227 u16 index; 228 struct xenvif_rx_cb *cb; 229 230 BUG_ON(skb->dev != dev); 231 232 /* Drop the packet if queues are not set up. 233 * This handler should be called inside an RCU read section 234 * so we don't need to enter it here explicitly. 235 */ 236 num_queues = READ_ONCE(vif->num_queues); 237 if (num_queues < 1) 238 goto drop; 239 240 /* Obtain the queue to be used to transmit this packet */ 241 index = skb_get_queue_mapping(skb); 242 if (index >= num_queues) { 243 pr_warn_ratelimited("Invalid queue %hu for packet on interface %s\n", 244 index, vif->dev->name); 245 index %= num_queues; 246 } 247 queue = &vif->queues[index]; 248 249 /* Drop the packet if queue is not ready */ 250 if (queue->task == NULL || 251 queue->dealloc_task == NULL || 252 !xenvif_schedulable(vif)) 253 goto drop; 254 255 if (vif->multicast_control && skb->pkt_type == PACKET_MULTICAST) { 256 struct ethhdr *eth = (struct ethhdr *)skb->data; 257 258 if (!xenvif_mcast_match(vif, eth->h_dest)) 259 goto drop; 260 } 261 262 cb = XENVIF_RX_CB(skb); 263 cb->expires = jiffies + vif->drain_timeout; 264 265 /* If there is no hash algorithm configured then make sure there 266 * is no hash information in the socket buffer otherwise it 267 * would be incorrectly forwarded to the frontend. 268 */ 269 if (vif->hash.alg == XEN_NETIF_CTRL_HASH_ALGORITHM_NONE) 270 skb_clear_hash(skb); 271 272 xenvif_rx_queue_tail(queue, skb); 273 xenvif_kick_thread(queue); 274 275 return NETDEV_TX_OK; 276 277 drop: 278 vif->dev->stats.tx_dropped++; 279 dev_kfree_skb(skb); 280 return NETDEV_TX_OK; 281 } 282 283 static struct net_device_stats *xenvif_get_stats(struct net_device *dev) 284 { 285 struct xenvif *vif = netdev_priv(dev); 286 struct xenvif_queue *queue = NULL; 287 unsigned int num_queues; 288 u64 rx_bytes = 0; 289 u64 rx_packets = 0; 290 u64 tx_bytes = 0; 291 u64 tx_packets = 0; 292 unsigned int index; 293 294 rcu_read_lock(); 295 num_queues = READ_ONCE(vif->num_queues); 296 297 /* Aggregate tx and rx stats from each queue */ 298 for (index = 0; index < num_queues; ++index) { 299 queue = &vif->queues[index]; 300 rx_bytes += queue->stats.rx_bytes; 301 rx_packets += queue->stats.rx_packets; 302 tx_bytes += queue->stats.tx_bytes; 303 tx_packets += queue->stats.tx_packets; 304 } 305 306 rcu_read_unlock(); 307 308 vif->dev->stats.rx_bytes = rx_bytes; 309 vif->dev->stats.rx_packets = rx_packets; 310 vif->dev->stats.tx_bytes = tx_bytes; 311 vif->dev->stats.tx_packets = tx_packets; 312 313 return &vif->dev->stats; 314 } 315 316 static void xenvif_up(struct xenvif *vif) 317 { 318 struct xenvif_queue *queue = NULL; 319 unsigned int num_queues = vif->num_queues; 320 unsigned int queue_index; 321 322 for (queue_index = 0; queue_index < num_queues; ++queue_index) { 323 queue = &vif->queues[queue_index]; 324 napi_enable(&queue->napi); 325 enable_irq(queue->tx_irq); 326 if (queue->tx_irq != queue->rx_irq) 327 enable_irq(queue->rx_irq); 328 xenvif_napi_schedule_or_enable_events(queue); 329 } 330 } 331 332 static void xenvif_down(struct xenvif *vif) 333 { 334 struct xenvif_queue *queue = NULL; 335 unsigned int num_queues = vif->num_queues; 336 unsigned int queue_index; 337 338 for (queue_index = 0; queue_index < num_queues; ++queue_index) { 339 queue = &vif->queues[queue_index]; 340 disable_irq(queue->tx_irq); 341 if (queue->tx_irq != queue->rx_irq) 342 disable_irq(queue->rx_irq); 343 napi_disable(&queue->napi); 344 del_timer_sync(&queue->credit_timeout); 345 } 346 } 347 348 static int xenvif_open(struct net_device *dev) 349 { 350 struct xenvif *vif = netdev_priv(dev); 351 if (test_bit(VIF_STATUS_CONNECTED, &vif->status)) 352 xenvif_up(vif); 353 netif_tx_start_all_queues(dev); 354 return 0; 355 } 356 357 static int xenvif_close(struct net_device *dev) 358 { 359 struct xenvif *vif = netdev_priv(dev); 360 if (test_bit(VIF_STATUS_CONNECTED, &vif->status)) 361 xenvif_down(vif); 362 netif_tx_stop_all_queues(dev); 363 return 0; 364 } 365 366 static int xenvif_change_mtu(struct net_device *dev, int mtu) 367 { 368 struct xenvif *vif = netdev_priv(dev); 369 int max = vif->can_sg ? ETH_MAX_MTU - VLAN_ETH_HLEN : ETH_DATA_LEN; 370 371 if (mtu > max) 372 return -EINVAL; 373 dev->mtu = mtu; 374 return 0; 375 } 376 377 static netdev_features_t xenvif_fix_features(struct net_device *dev, 378 netdev_features_t features) 379 { 380 struct xenvif *vif = netdev_priv(dev); 381 382 if (!vif->can_sg) 383 features &= ~NETIF_F_SG; 384 if (~(vif->gso_mask) & GSO_BIT(TCPV4)) 385 features &= ~NETIF_F_TSO; 386 if (~(vif->gso_mask) & GSO_BIT(TCPV6)) 387 features &= ~NETIF_F_TSO6; 388 if (!vif->ip_csum) 389 features &= ~NETIF_F_IP_CSUM; 390 if (!vif->ipv6_csum) 391 features &= ~NETIF_F_IPV6_CSUM; 392 393 return features; 394 } 395 396 static const struct xenvif_stat { 397 char name[ETH_GSTRING_LEN]; 398 u16 offset; 399 } xenvif_stats[] = { 400 { 401 "rx_gso_checksum_fixup", 402 offsetof(struct xenvif_stats, rx_gso_checksum_fixup) 403 }, 404 /* If (sent != success + fail), there are probably packets never 405 * freed up properly! 406 */ 407 { 408 "tx_zerocopy_sent", 409 offsetof(struct xenvif_stats, tx_zerocopy_sent), 410 }, 411 { 412 "tx_zerocopy_success", 413 offsetof(struct xenvif_stats, tx_zerocopy_success), 414 }, 415 { 416 "tx_zerocopy_fail", 417 offsetof(struct xenvif_stats, tx_zerocopy_fail) 418 }, 419 /* Number of packets exceeding MAX_SKB_FRAG slots. You should use 420 * a guest with the same MAX_SKB_FRAG 421 */ 422 { 423 "tx_frag_overflow", 424 offsetof(struct xenvif_stats, tx_frag_overflow) 425 }, 426 }; 427 428 static int xenvif_get_sset_count(struct net_device *dev, int string_set) 429 { 430 switch (string_set) { 431 case ETH_SS_STATS: 432 return ARRAY_SIZE(xenvif_stats); 433 default: 434 return -EINVAL; 435 } 436 } 437 438 static void xenvif_get_ethtool_stats(struct net_device *dev, 439 struct ethtool_stats *stats, u64 * data) 440 { 441 struct xenvif *vif = netdev_priv(dev); 442 unsigned int num_queues; 443 int i; 444 unsigned int queue_index; 445 446 rcu_read_lock(); 447 num_queues = READ_ONCE(vif->num_queues); 448 449 for (i = 0; i < ARRAY_SIZE(xenvif_stats); i++) { 450 unsigned long accum = 0; 451 for (queue_index = 0; queue_index < num_queues; ++queue_index) { 452 void *vif_stats = &vif->queues[queue_index].stats; 453 accum += *(unsigned long *)(vif_stats + xenvif_stats[i].offset); 454 } 455 data[i] = accum; 456 } 457 458 rcu_read_unlock(); 459 } 460 461 static void xenvif_get_strings(struct net_device *dev, u32 stringset, u8 * data) 462 { 463 int i; 464 465 switch (stringset) { 466 case ETH_SS_STATS: 467 for (i = 0; i < ARRAY_SIZE(xenvif_stats); i++) 468 memcpy(data + i * ETH_GSTRING_LEN, 469 xenvif_stats[i].name, ETH_GSTRING_LEN); 470 break; 471 } 472 } 473 474 static const struct ethtool_ops xenvif_ethtool_ops = { 475 .get_link = ethtool_op_get_link, 476 477 .get_sset_count = xenvif_get_sset_count, 478 .get_ethtool_stats = xenvif_get_ethtool_stats, 479 .get_strings = xenvif_get_strings, 480 }; 481 482 static const struct net_device_ops xenvif_netdev_ops = { 483 .ndo_select_queue = xenvif_select_queue, 484 .ndo_start_xmit = xenvif_start_xmit, 485 .ndo_get_stats = xenvif_get_stats, 486 .ndo_open = xenvif_open, 487 .ndo_stop = xenvif_close, 488 .ndo_change_mtu = xenvif_change_mtu, 489 .ndo_fix_features = xenvif_fix_features, 490 .ndo_set_mac_address = eth_mac_addr, 491 .ndo_validate_addr = eth_validate_addr, 492 }; 493 494 struct xenvif *xenvif_alloc(struct device *parent, domid_t domid, 495 unsigned int handle) 496 { 497 static const u8 dummy_addr[ETH_ALEN] = { 498 0xfe, 0xff, 0xff, 0xff, 0xff, 0xff, 499 }; 500 int err; 501 struct net_device *dev; 502 struct xenvif *vif; 503 char name[IFNAMSIZ] = {}; 504 505 snprintf(name, IFNAMSIZ - 1, "vif%u.%u", domid, handle); 506 /* Allocate a netdev with the max. supported number of queues. 507 * When the guest selects the desired number, it will be updated 508 * via netif_set_real_num_*_queues(). 509 */ 510 dev = alloc_netdev_mq(sizeof(struct xenvif), name, NET_NAME_UNKNOWN, 511 ether_setup, xenvif_max_queues); 512 if (dev == NULL) { 513 pr_warn("Could not allocate netdev for %s\n", name); 514 return ERR_PTR(-ENOMEM); 515 } 516 517 SET_NETDEV_DEV(dev, parent); 518 519 vif = netdev_priv(dev); 520 521 vif->domid = domid; 522 vif->handle = handle; 523 vif->can_sg = 1; 524 vif->ip_csum = 1; 525 vif->dev = dev; 526 vif->disabled = false; 527 vif->drain_timeout = msecs_to_jiffies(rx_drain_timeout_msecs); 528 vif->stall_timeout = msecs_to_jiffies(rx_stall_timeout_msecs); 529 530 /* Start out with no queues. */ 531 vif->queues = NULL; 532 vif->num_queues = 0; 533 534 vif->xdp_headroom = 0; 535 536 spin_lock_init(&vif->lock); 537 INIT_LIST_HEAD(&vif->fe_mcast_addr); 538 539 dev->netdev_ops = &xenvif_netdev_ops; 540 dev->hw_features = NETIF_F_SG | 541 NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM | 542 NETIF_F_TSO | NETIF_F_TSO6 | NETIF_F_FRAGLIST; 543 dev->features = dev->hw_features | NETIF_F_RXCSUM; 544 dev->ethtool_ops = &xenvif_ethtool_ops; 545 546 dev->tx_queue_len = XENVIF_QUEUE_LENGTH; 547 548 dev->min_mtu = ETH_MIN_MTU; 549 dev->max_mtu = ETH_MAX_MTU - VLAN_ETH_HLEN; 550 551 /* 552 * Initialise a dummy MAC address. We choose the numerically 553 * largest non-broadcast address to prevent the address getting 554 * stolen by an Ethernet bridge for STP purposes. 555 * (FE:FF:FF:FF:FF:FF) 556 */ 557 eth_hw_addr_set(dev, dummy_addr); 558 559 netif_carrier_off(dev); 560 561 err = register_netdev(dev); 562 if (err) { 563 netdev_warn(dev, "Could not register device: err=%d\n", err); 564 free_netdev(dev); 565 return ERR_PTR(err); 566 } 567 568 netdev_dbg(dev, "Successfully created xenvif\n"); 569 570 __module_get(THIS_MODULE); 571 572 return vif; 573 } 574 575 int xenvif_init_queue(struct xenvif_queue *queue) 576 { 577 int err, i; 578 579 queue->credit_bytes = queue->remaining_credit = ~0UL; 580 queue->credit_usec = 0UL; 581 timer_setup(&queue->credit_timeout, xenvif_tx_credit_callback, 0); 582 queue->credit_window_start = get_jiffies_64(); 583 584 queue->rx_queue_max = XENVIF_RX_QUEUE_BYTES; 585 586 skb_queue_head_init(&queue->rx_queue); 587 skb_queue_head_init(&queue->tx_queue); 588 589 queue->pending_cons = 0; 590 queue->pending_prod = MAX_PENDING_REQS; 591 for (i = 0; i < MAX_PENDING_REQS; ++i) 592 queue->pending_ring[i] = i; 593 594 spin_lock_init(&queue->callback_lock); 595 spin_lock_init(&queue->response_lock); 596 597 /* If ballooning is disabled, this will consume real memory, so you 598 * better enable it. The long term solution would be to use just a 599 * bunch of valid page descriptors, without dependency on ballooning 600 */ 601 err = gnttab_alloc_pages(MAX_PENDING_REQS, 602 queue->mmap_pages); 603 if (err) { 604 netdev_err(queue->vif->dev, "Could not reserve mmap_pages\n"); 605 return -ENOMEM; 606 } 607 608 for (i = 0; i < MAX_PENDING_REQS; i++) { 609 queue->pending_tx_info[i].callback_struct = (struct ubuf_info) 610 { .callback = xenvif_zerocopy_callback, 611 { { .ctx = NULL, 612 .desc = i } } }; 613 queue->grant_tx_handle[i] = NETBACK_INVALID_HANDLE; 614 } 615 616 return 0; 617 } 618 619 void xenvif_carrier_on(struct xenvif *vif) 620 { 621 rtnl_lock(); 622 if (!vif->can_sg && vif->dev->mtu > ETH_DATA_LEN) 623 dev_set_mtu(vif->dev, ETH_DATA_LEN); 624 netdev_update_features(vif->dev); 625 set_bit(VIF_STATUS_CONNECTED, &vif->status); 626 if (netif_running(vif->dev)) 627 xenvif_up(vif); 628 rtnl_unlock(); 629 } 630 631 int xenvif_connect_ctrl(struct xenvif *vif, grant_ref_t ring_ref, 632 unsigned int evtchn) 633 { 634 struct net_device *dev = vif->dev; 635 struct xenbus_device *xendev = xenvif_to_xenbus_device(vif); 636 void *addr; 637 struct xen_netif_ctrl_sring *shared; 638 RING_IDX rsp_prod, req_prod; 639 int err; 640 641 err = xenbus_map_ring_valloc(xendev, &ring_ref, 1, &addr); 642 if (err) 643 goto err; 644 645 shared = (struct xen_netif_ctrl_sring *)addr; 646 rsp_prod = READ_ONCE(shared->rsp_prod); 647 req_prod = READ_ONCE(shared->req_prod); 648 649 BACK_RING_ATTACH(&vif->ctrl, shared, rsp_prod, XEN_PAGE_SIZE); 650 651 err = -EIO; 652 if (req_prod - rsp_prod > RING_SIZE(&vif->ctrl)) 653 goto err_unmap; 654 655 err = bind_interdomain_evtchn_to_irq_lateeoi(xendev, evtchn); 656 if (err < 0) 657 goto err_unmap; 658 659 vif->ctrl_irq = err; 660 661 xenvif_init_hash(vif); 662 663 err = request_threaded_irq(vif->ctrl_irq, NULL, xenvif_ctrl_irq_fn, 664 IRQF_ONESHOT, "xen-netback-ctrl", vif); 665 if (err) { 666 pr_warn("Could not setup irq handler for %s\n", dev->name); 667 goto err_deinit; 668 } 669 670 return 0; 671 672 err_deinit: 673 xenvif_deinit_hash(vif); 674 unbind_from_irqhandler(vif->ctrl_irq, vif); 675 vif->ctrl_irq = 0; 676 677 err_unmap: 678 xenbus_unmap_ring_vfree(xendev, vif->ctrl.sring); 679 vif->ctrl.sring = NULL; 680 681 err: 682 return err; 683 } 684 685 static void xenvif_disconnect_queue(struct xenvif_queue *queue) 686 { 687 if (queue->task) { 688 kthread_stop(queue->task); 689 put_task_struct(queue->task); 690 queue->task = NULL; 691 } 692 693 if (queue->dealloc_task) { 694 kthread_stop(queue->dealloc_task); 695 queue->dealloc_task = NULL; 696 } 697 698 if (queue->napi.poll) { 699 netif_napi_del(&queue->napi); 700 queue->napi.poll = NULL; 701 } 702 703 if (queue->tx_irq) { 704 unbind_from_irqhandler(queue->tx_irq, queue); 705 if (queue->tx_irq == queue->rx_irq) 706 queue->rx_irq = 0; 707 queue->tx_irq = 0; 708 } 709 710 if (queue->rx_irq) { 711 unbind_from_irqhandler(queue->rx_irq, queue); 712 queue->rx_irq = 0; 713 } 714 715 xenvif_unmap_frontend_data_rings(queue); 716 } 717 718 int xenvif_connect_data(struct xenvif_queue *queue, 719 unsigned long tx_ring_ref, 720 unsigned long rx_ring_ref, 721 unsigned int tx_evtchn, 722 unsigned int rx_evtchn) 723 { 724 struct xenbus_device *dev = xenvif_to_xenbus_device(queue->vif); 725 struct task_struct *task; 726 int err; 727 728 BUG_ON(queue->tx_irq); 729 BUG_ON(queue->task); 730 BUG_ON(queue->dealloc_task); 731 732 err = xenvif_map_frontend_data_rings(queue, tx_ring_ref, 733 rx_ring_ref); 734 if (err < 0) 735 goto err; 736 737 init_waitqueue_head(&queue->wq); 738 init_waitqueue_head(&queue->dealloc_wq); 739 atomic_set(&queue->inflight_packets, 0); 740 741 netif_napi_add(queue->vif->dev, &queue->napi, xenvif_poll, 742 XENVIF_NAPI_WEIGHT); 743 744 queue->stalled = true; 745 746 task = kthread_run(xenvif_kthread_guest_rx, queue, 747 "%s-guest-rx", queue->name); 748 if (IS_ERR(task)) 749 goto kthread_err; 750 queue->task = task; 751 /* 752 * Take a reference to the task in order to prevent it from being freed 753 * if the thread function returns before kthread_stop is called. 754 */ 755 get_task_struct(task); 756 757 task = kthread_run(xenvif_dealloc_kthread, queue, 758 "%s-dealloc", queue->name); 759 if (IS_ERR(task)) 760 goto kthread_err; 761 queue->dealloc_task = task; 762 763 if (tx_evtchn == rx_evtchn) { 764 /* feature-split-event-channels == 0 */ 765 err = bind_interdomain_evtchn_to_irqhandler_lateeoi( 766 dev, tx_evtchn, xenvif_interrupt, 0, 767 queue->name, queue); 768 if (err < 0) 769 goto err; 770 queue->tx_irq = queue->rx_irq = err; 771 disable_irq(queue->tx_irq); 772 } else { 773 /* feature-split-event-channels == 1 */ 774 snprintf(queue->tx_irq_name, sizeof(queue->tx_irq_name), 775 "%s-tx", queue->name); 776 err = bind_interdomain_evtchn_to_irqhandler_lateeoi( 777 dev, tx_evtchn, xenvif_tx_interrupt, 0, 778 queue->tx_irq_name, queue); 779 if (err < 0) 780 goto err; 781 queue->tx_irq = err; 782 disable_irq(queue->tx_irq); 783 784 snprintf(queue->rx_irq_name, sizeof(queue->rx_irq_name), 785 "%s-rx", queue->name); 786 err = bind_interdomain_evtchn_to_irqhandler_lateeoi( 787 dev, rx_evtchn, xenvif_rx_interrupt, 0, 788 queue->rx_irq_name, queue); 789 if (err < 0) 790 goto err; 791 queue->rx_irq = err; 792 disable_irq(queue->rx_irq); 793 } 794 795 return 0; 796 797 kthread_err: 798 pr_warn("Could not allocate kthread for %s\n", queue->name); 799 err = PTR_ERR(task); 800 err: 801 xenvif_disconnect_queue(queue); 802 return err; 803 } 804 805 void xenvif_carrier_off(struct xenvif *vif) 806 { 807 struct net_device *dev = vif->dev; 808 809 rtnl_lock(); 810 if (test_and_clear_bit(VIF_STATUS_CONNECTED, &vif->status)) { 811 netif_carrier_off(dev); /* discard queued packets */ 812 if (netif_running(dev)) 813 xenvif_down(vif); 814 } 815 rtnl_unlock(); 816 } 817 818 void xenvif_disconnect_data(struct xenvif *vif) 819 { 820 struct xenvif_queue *queue = NULL; 821 unsigned int num_queues = vif->num_queues; 822 unsigned int queue_index; 823 824 xenvif_carrier_off(vif); 825 826 for (queue_index = 0; queue_index < num_queues; ++queue_index) { 827 queue = &vif->queues[queue_index]; 828 829 xenvif_disconnect_queue(queue); 830 } 831 832 xenvif_mcast_addr_list_free(vif); 833 } 834 835 void xenvif_disconnect_ctrl(struct xenvif *vif) 836 { 837 if (vif->ctrl_irq) { 838 xenvif_deinit_hash(vif); 839 unbind_from_irqhandler(vif->ctrl_irq, vif); 840 vif->ctrl_irq = 0; 841 } 842 843 if (vif->ctrl.sring) { 844 xenbus_unmap_ring_vfree(xenvif_to_xenbus_device(vif), 845 vif->ctrl.sring); 846 vif->ctrl.sring = NULL; 847 } 848 } 849 850 /* Reverse the relevant parts of xenvif_init_queue(). 851 * Used for queue teardown from xenvif_free(), and on the 852 * error handling paths in xenbus.c:connect(). 853 */ 854 void xenvif_deinit_queue(struct xenvif_queue *queue) 855 { 856 gnttab_free_pages(MAX_PENDING_REQS, queue->mmap_pages); 857 } 858 859 void xenvif_free(struct xenvif *vif) 860 { 861 struct xenvif_queue *queues = vif->queues; 862 unsigned int num_queues = vif->num_queues; 863 unsigned int queue_index; 864 865 unregister_netdev(vif->dev); 866 free_netdev(vif->dev); 867 868 for (queue_index = 0; queue_index < num_queues; ++queue_index) 869 xenvif_deinit_queue(&queues[queue_index]); 870 vfree(queues); 871 872 module_put(THIS_MODULE); 873 } 874