1/* 2 * Virtual network driver for conversing with remote driver backends. 3 * 4 * Copyright (c) 2002-2005, K A Fraser 5 * Copyright (c) 2005, XenSource Ltd 6 * 7 * This program is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU General Public License version 2 9 * as published by the Free Software Foundation; or, when distributed 10 * separately from the Linux kernel or incorporated into other 11 * software packages, subject to the following license: 12 * 13 * Permission is hereby granted, free of charge, to any person obtaining a copy 14 * of this source file (the "Software"), to deal in the Software without 15 * restriction, including without limitation the rights to use, copy, modify, 16 * merge, publish, distribute, sublicense, and/or sell copies of the Software, 17 * and to permit persons to whom the Software is furnished to do so, subject to 18 * the following conditions: 19 * 20 * The above copyright notice and this permission notice shall be included in 21 * all copies or substantial portions of the Software. 22 * 23 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 24 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 25 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 26 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 27 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 28 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS 29 * IN THE SOFTWARE. 30 */ 31 32#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 33 34#include <linux/module.h> 35#include <linux/kernel.h> 36#include <linux/netdevice.h> 37#include <linux/etherdevice.h> 38#include <linux/skbuff.h> 39#include <linux/ethtool.h> 40#include <linux/if_ether.h> 41#include <net/tcp.h> 42#include <linux/udp.h> 43#include <linux/moduleparam.h> 44#include <linux/mm.h> 45#include <linux/slab.h> 46#include <net/ip.h> 47#include <linux/bpf.h> 48#include <net/page_pool/types.h> 49#include <linux/bpf_trace.h> 50 51#include <xen/xen.h> 52#include <xen/xenbus.h> 53#include <xen/events.h> 54#include <xen/page.h> 55#include <xen/platform_pci.h> 56#include <xen/grant_table.h> 57 58#include <xen/interface/io/netif.h> 59#include <xen/interface/memory.h> 60#include <xen/interface/grant_table.h> 61 62/* Module parameters */ 63#define MAX_QUEUES_DEFAULT 8 64static unsigned int xennet_max_queues; 65module_param_named(max_queues, xennet_max_queues, uint, 0644); 66MODULE_PARM_DESC(max_queues, 67 "Maximum number of queues per virtual interface"); 68 69static bool __read_mostly xennet_trusted = true; 70module_param_named(trusted, xennet_trusted, bool, 0644); 71MODULE_PARM_DESC(trusted, "Is the backend trusted"); 72 73#define XENNET_TIMEOUT (5 * HZ) 74 75static const struct ethtool_ops xennet_ethtool_ops; 76 77struct netfront_cb { 78 int pull_to; 79}; 80 81#define NETFRONT_SKB_CB(skb) ((struct netfront_cb *)((skb)->cb)) 82 83#define RX_COPY_THRESHOLD 256 84 85#define NET_TX_RING_SIZE __CONST_RING_SIZE(xen_netif_tx, XEN_PAGE_SIZE) 86#define NET_RX_RING_SIZE __CONST_RING_SIZE(xen_netif_rx, XEN_PAGE_SIZE) 87 88/* Minimum number of Rx slots (includes slot for GSO metadata). */ 89#define NET_RX_SLOTS_MIN (XEN_NETIF_NR_SLOTS_MIN + 1) 90 91/* Queue name is interface name with "-qNNN" appended */ 92#define QUEUE_NAME_SIZE (IFNAMSIZ + 6) 93 94/* IRQ name is queue name with "-tx" or "-rx" appended */ 95#define IRQ_NAME_SIZE (QUEUE_NAME_SIZE + 3) 96 97static DECLARE_WAIT_QUEUE_HEAD(module_wq); 98 99struct netfront_stats { 100 u64 packets; 101 u64 bytes; 102 struct u64_stats_sync syncp; 103}; 104 105struct netfront_info; 106 107struct netfront_queue { 108 unsigned int id; /* Queue ID, 0-based */ 109 char name[QUEUE_NAME_SIZE]; /* DEVNAME-qN */ 110 struct netfront_info *info; 111 112 struct bpf_prog __rcu *xdp_prog; 113 114 struct napi_struct napi; 115 116 /* Split event channels support, tx_* == rx_* when using 117 * single event channel. 118 */ 119 unsigned int tx_evtchn, rx_evtchn; 120 unsigned int tx_irq, rx_irq; 121 /* Only used when split event channels support is enabled */ 122 char tx_irq_name[IRQ_NAME_SIZE]; /* DEVNAME-qN-tx */ 123 char rx_irq_name[IRQ_NAME_SIZE]; /* DEVNAME-qN-rx */ 124 125 spinlock_t tx_lock; 126 struct xen_netif_tx_front_ring tx; 127 int tx_ring_ref; 128 129 /* 130 * {tx,rx}_skbs store outstanding skbuffs. Free tx_skb entries 131 * are linked from tx_skb_freelist through tx_link. 132 */ 133 struct sk_buff *tx_skbs[NET_TX_RING_SIZE]; 134 unsigned short tx_link[NET_TX_RING_SIZE]; 135#define TX_LINK_NONE 0xffff 136#define TX_PENDING 0xfffe 137 grant_ref_t gref_tx_head; 138 grant_ref_t grant_tx_ref[NET_TX_RING_SIZE]; 139 struct page *grant_tx_page[NET_TX_RING_SIZE]; 140 unsigned tx_skb_freelist; 141 unsigned int tx_pend_queue; 142 143 spinlock_t rx_lock ____cacheline_aligned_in_smp; 144 struct xen_netif_rx_front_ring rx; 145 int rx_ring_ref; 146 147 struct timer_list rx_refill_timer; 148 149 struct sk_buff *rx_skbs[NET_RX_RING_SIZE]; 150 grant_ref_t gref_rx_head; 151 grant_ref_t grant_rx_ref[NET_RX_RING_SIZE]; 152 153 unsigned int rx_rsp_unconsumed; 154 spinlock_t rx_cons_lock; 155 156 struct page_pool *page_pool; 157 struct xdp_rxq_info xdp_rxq; 158}; 159 160struct netfront_info { 161 struct list_head list; 162 struct net_device *netdev; 163 164 struct xenbus_device *xbdev; 165 166 /* Multi-queue support */ 167 struct netfront_queue *queues; 168 169 /* Statistics */ 170 struct netfront_stats __percpu *rx_stats; 171 struct netfront_stats __percpu *tx_stats; 172 173 /* XDP state */ 174 bool netback_has_xdp_headroom; 175 bool netfront_xdp_enabled; 176 177 /* Is device behaving sane? */ 178 bool broken; 179 180 /* Should skbs be bounced into a zeroed buffer? */ 181 bool bounce; 182 183 atomic_t rx_gso_checksum_fixup; 184}; 185 186struct netfront_rx_info { 187 struct xen_netif_rx_response rx; 188 struct xen_netif_extra_info extras[XEN_NETIF_EXTRA_TYPE_MAX - 1]; 189}; 190 191/* 192 * Access macros for acquiring freeing slots in tx_skbs[]. 193 */ 194 195static void add_id_to_list(unsigned *head, unsigned short *list, 196 unsigned short id) 197{ 198 list[id] = *head; 199 *head = id; 200} 201 202static unsigned short get_id_from_list(unsigned *head, unsigned short *list) 203{ 204 unsigned int id = *head; 205 206 if (id != TX_LINK_NONE) { 207 *head = list[id]; 208 list[id] = TX_LINK_NONE; 209 } 210 return id; 211} 212 213static int xennet_rxidx(RING_IDX idx) 214{ 215 return idx & (NET_RX_RING_SIZE - 1); 216} 217 218static struct sk_buff *xennet_get_rx_skb(struct netfront_queue *queue, 219 RING_IDX ri) 220{ 221 int i = xennet_rxidx(ri); 222 struct sk_buff *skb = queue->rx_skbs[i]; 223 queue->rx_skbs[i] = NULL; 224 return skb; 225} 226 227static grant_ref_t xennet_get_rx_ref(struct netfront_queue *queue, 228 RING_IDX ri) 229{ 230 int i = xennet_rxidx(ri); 231 grant_ref_t ref = queue->grant_rx_ref[i]; 232 queue->grant_rx_ref[i] = INVALID_GRANT_REF; 233 return ref; 234} 235 236#ifdef CONFIG_SYSFS 237static const struct attribute_group xennet_dev_group; 238#endif 239 240static bool xennet_can_sg(struct net_device *dev) 241{ 242 return dev->features & NETIF_F_SG; 243} 244 245 246static void rx_refill_timeout(struct timer_list *t) 247{ 248 struct netfront_queue *queue = from_timer(queue, t, rx_refill_timer); 249 napi_schedule(&queue->napi); 250} 251 252static int netfront_tx_slot_available(struct netfront_queue *queue) 253{ 254 return (queue->tx.req_prod_pvt - queue->tx.rsp_cons) < 255 (NET_TX_RING_SIZE - XEN_NETIF_NR_SLOTS_MIN - 1); 256} 257 258static void xennet_maybe_wake_tx(struct netfront_queue *queue) 259{ 260 struct net_device *dev = queue->info->netdev; 261 struct netdev_queue *dev_queue = netdev_get_tx_queue(dev, queue->id); 262 263 if (unlikely(netif_tx_queue_stopped(dev_queue)) && 264 netfront_tx_slot_available(queue) && 265 likely(netif_running(dev))) 266 netif_tx_wake_queue(netdev_get_tx_queue(dev, queue->id)); 267} 268 269 270static struct sk_buff *xennet_alloc_one_rx_buffer(struct netfront_queue *queue) 271{ 272 struct sk_buff *skb; 273 struct page *page; 274 275 skb = __netdev_alloc_skb(queue->info->netdev, 276 RX_COPY_THRESHOLD + NET_IP_ALIGN, 277 GFP_ATOMIC | __GFP_NOWARN); 278 if (unlikely(!skb)) 279 return NULL; 280 281 page = page_pool_alloc_pages(queue->page_pool, 282 GFP_ATOMIC | __GFP_NOWARN | __GFP_ZERO); 283 if (unlikely(!page)) { 284 kfree_skb(skb); 285 return NULL; 286 } 287 skb_add_rx_frag(skb, 0, page, 0, 0, PAGE_SIZE); 288 skb_mark_for_recycle(skb); 289 290 /* Align ip header to a 16 bytes boundary */ 291 skb_reserve(skb, NET_IP_ALIGN); 292 skb->dev = queue->info->netdev; 293 294 return skb; 295} 296 297 298static void xennet_alloc_rx_buffers(struct netfront_queue *queue) 299{ 300 RING_IDX req_prod = queue->rx.req_prod_pvt; 301 int notify; 302 int err = 0; 303 304 if (unlikely(!netif_carrier_ok(queue->info->netdev))) 305 return; 306 307 for (req_prod = queue->rx.req_prod_pvt; 308 req_prod - queue->rx.rsp_cons < NET_RX_RING_SIZE; 309 req_prod++) { 310 struct sk_buff *skb; 311 unsigned short id; 312 grant_ref_t ref; 313 struct page *page; 314 struct xen_netif_rx_request *req; 315 316 skb = xennet_alloc_one_rx_buffer(queue); 317 if (!skb) { 318 err = -ENOMEM; 319 break; 320 } 321 322 id = xennet_rxidx(req_prod); 323 324 BUG_ON(queue->rx_skbs[id]); 325 queue->rx_skbs[id] = skb; 326 327 ref = gnttab_claim_grant_reference(&queue->gref_rx_head); 328 WARN_ON_ONCE(IS_ERR_VALUE((unsigned long)(int)ref)); 329 queue->grant_rx_ref[id] = ref; 330 331 page = skb_frag_page(&skb_shinfo(skb)->frags[0]); 332 333 req = RING_GET_REQUEST(&queue->rx, req_prod); 334 gnttab_page_grant_foreign_access_ref_one(ref, 335 queue->info->xbdev->otherend_id, 336 page, 337 0); 338 req->id = id; 339 req->gref = ref; 340 } 341 342 queue->rx.req_prod_pvt = req_prod; 343 344 /* Try again later if there are not enough requests or skb allocation 345 * failed. 346 * Enough requests is quantified as the sum of newly created slots and 347 * the unconsumed slots at the backend. 348 */ 349 if (req_prod - queue->rx.rsp_cons < NET_RX_SLOTS_MIN || 350 unlikely(err)) { 351 mod_timer(&queue->rx_refill_timer, jiffies + (HZ/10)); 352 return; 353 } 354 355 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->rx, notify); 356 if (notify) 357 notify_remote_via_irq(queue->rx_irq); 358} 359 360static int xennet_open(struct net_device *dev) 361{ 362 struct netfront_info *np = netdev_priv(dev); 363 unsigned int num_queues = dev->real_num_tx_queues; 364 unsigned int i = 0; 365 struct netfront_queue *queue = NULL; 366 367 if (!np->queues || np->broken) 368 return -ENODEV; 369 370 for (i = 0; i < num_queues; ++i) { 371 queue = &np->queues[i]; 372 napi_enable(&queue->napi); 373 374 spin_lock_bh(&queue->rx_lock); 375 if (netif_carrier_ok(dev)) { 376 xennet_alloc_rx_buffers(queue); 377 queue->rx.sring->rsp_event = queue->rx.rsp_cons + 1; 378 if (RING_HAS_UNCONSUMED_RESPONSES(&queue->rx)) 379 napi_schedule(&queue->napi); 380 } 381 spin_unlock_bh(&queue->rx_lock); 382 } 383 384 netif_tx_start_all_queues(dev); 385 386 return 0; 387} 388 389static bool xennet_tx_buf_gc(struct netfront_queue *queue) 390{ 391 RING_IDX cons, prod; 392 unsigned short id; 393 struct sk_buff *skb; 394 bool more_to_do; 395 bool work_done = false; 396 const struct device *dev = &queue->info->netdev->dev; 397 398 BUG_ON(!netif_carrier_ok(queue->info->netdev)); 399 400 do { 401 prod = queue->tx.sring->rsp_prod; 402 if (RING_RESPONSE_PROD_OVERFLOW(&queue->tx, prod)) { 403 dev_alert(dev, "Illegal number of responses %u\n", 404 prod - queue->tx.rsp_cons); 405 goto err; 406 } 407 rmb(); /* Ensure we see responses up to 'rp'. */ 408 409 for (cons = queue->tx.rsp_cons; cons != prod; cons++) { 410 struct xen_netif_tx_response txrsp; 411 412 work_done = true; 413 414 RING_COPY_RESPONSE(&queue->tx, cons, &txrsp); 415 if (txrsp.status == XEN_NETIF_RSP_NULL) 416 continue; 417 418 id = txrsp.id; 419 if (id >= RING_SIZE(&queue->tx)) { 420 dev_alert(dev, 421 "Response has incorrect id (%u)\n", 422 id); 423 goto err; 424 } 425 if (queue->tx_link[id] != TX_PENDING) { 426 dev_alert(dev, 427 "Response for inactive request\n"); 428 goto err; 429 } 430 431 queue->tx_link[id] = TX_LINK_NONE; 432 skb = queue->tx_skbs[id]; 433 queue->tx_skbs[id] = NULL; 434 if (unlikely(!gnttab_end_foreign_access_ref( 435 queue->grant_tx_ref[id]))) { 436 dev_alert(dev, 437 "Grant still in use by backend domain\n"); 438 goto err; 439 } 440 gnttab_release_grant_reference( 441 &queue->gref_tx_head, queue->grant_tx_ref[id]); 442 queue->grant_tx_ref[id] = INVALID_GRANT_REF; 443 queue->grant_tx_page[id] = NULL; 444 add_id_to_list(&queue->tx_skb_freelist, queue->tx_link, id); 445 dev_kfree_skb_irq(skb); 446 } 447 448 queue->tx.rsp_cons = prod; 449 450 RING_FINAL_CHECK_FOR_RESPONSES(&queue->tx, more_to_do); 451 } while (more_to_do); 452 453 xennet_maybe_wake_tx(queue); 454 455 return work_done; 456 457 err: 458 queue->info->broken = true; 459 dev_alert(dev, "Disabled for further use\n"); 460 461 return work_done; 462} 463 464struct xennet_gnttab_make_txreq { 465 struct netfront_queue *queue; 466 struct sk_buff *skb; 467 struct page *page; 468 struct xen_netif_tx_request *tx; /* Last request on ring page */ 469 struct xen_netif_tx_request tx_local; /* Last request local copy*/ 470 unsigned int size; 471}; 472 473static void xennet_tx_setup_grant(unsigned long gfn, unsigned int offset, 474 unsigned int len, void *data) 475{ 476 struct xennet_gnttab_make_txreq *info = data; 477 unsigned int id; 478 struct xen_netif_tx_request *tx; 479 grant_ref_t ref; 480 /* convenient aliases */ 481 struct page *page = info->page; 482 struct netfront_queue *queue = info->queue; 483 struct sk_buff *skb = info->skb; 484 485 id = get_id_from_list(&queue->tx_skb_freelist, queue->tx_link); 486 tx = RING_GET_REQUEST(&queue->tx, queue->tx.req_prod_pvt++); 487 ref = gnttab_claim_grant_reference(&queue->gref_tx_head); 488 WARN_ON_ONCE(IS_ERR_VALUE((unsigned long)(int)ref)); 489 490 gnttab_grant_foreign_access_ref(ref, queue->info->xbdev->otherend_id, 491 gfn, GNTMAP_readonly); 492 493 queue->tx_skbs[id] = skb; 494 queue->grant_tx_page[id] = page; 495 queue->grant_tx_ref[id] = ref; 496 497 info->tx_local.id = id; 498 info->tx_local.gref = ref; 499 info->tx_local.offset = offset; 500 info->tx_local.size = len; 501 info->tx_local.flags = 0; 502 503 *tx = info->tx_local; 504 505 /* 506 * Put the request in the pending queue, it will be set to be pending 507 * when the producer index is about to be raised. 508 */ 509 add_id_to_list(&queue->tx_pend_queue, queue->tx_link, id); 510 511 info->tx = tx; 512 info->size += info->tx_local.size; 513} 514 515static struct xen_netif_tx_request *xennet_make_first_txreq( 516 struct xennet_gnttab_make_txreq *info, 517 unsigned int offset, unsigned int len) 518{ 519 info->size = 0; 520 521 gnttab_for_one_grant(info->page, offset, len, xennet_tx_setup_grant, info); 522 523 return info->tx; 524} 525 526static void xennet_make_one_txreq(unsigned long gfn, unsigned int offset, 527 unsigned int len, void *data) 528{ 529 struct xennet_gnttab_make_txreq *info = data; 530 531 info->tx->flags |= XEN_NETTXF_more_data; 532 skb_get(info->skb); 533 xennet_tx_setup_grant(gfn, offset, len, data); 534} 535 536static void xennet_make_txreqs( 537 struct xennet_gnttab_make_txreq *info, 538 struct page *page, 539 unsigned int offset, unsigned int len) 540{ 541 /* Skip unused frames from start of page */ 542 page += offset >> PAGE_SHIFT; 543 offset &= ~PAGE_MASK; 544 545 while (len) { 546 info->page = page; 547 info->size = 0; 548 549 gnttab_foreach_grant_in_range(page, offset, len, 550 xennet_make_one_txreq, 551 info); 552 553 page++; 554 offset = 0; 555 len -= info->size; 556 } 557} 558 559/* 560 * Count how many ring slots are required to send this skb. Each frag 561 * might be a compound page. 562 */ 563static int xennet_count_skb_slots(struct sk_buff *skb) 564{ 565 int i, frags = skb_shinfo(skb)->nr_frags; 566 int slots; 567 568 slots = gnttab_count_grant(offset_in_page(skb->data), 569 skb_headlen(skb)); 570 571 for (i = 0; i < frags; i++) { 572 skb_frag_t *frag = skb_shinfo(skb)->frags + i; 573 unsigned long size = skb_frag_size(frag); 574 unsigned long offset = skb_frag_off(frag); 575 576 /* Skip unused frames from start of page */ 577 offset &= ~PAGE_MASK; 578 579 slots += gnttab_count_grant(offset, size); 580 } 581 582 return slots; 583} 584 585static u16 xennet_select_queue(struct net_device *dev, struct sk_buff *skb, 586 struct net_device *sb_dev) 587{ 588 unsigned int num_queues = dev->real_num_tx_queues; 589 u32 hash; 590 u16 queue_idx; 591 592 /* First, check if there is only one queue */ 593 if (num_queues == 1) { 594 queue_idx = 0; 595 } else { 596 hash = skb_get_hash(skb); 597 queue_idx = hash % num_queues; 598 } 599 600 return queue_idx; 601} 602 603static void xennet_mark_tx_pending(struct netfront_queue *queue) 604{ 605 unsigned int i; 606 607 while ((i = get_id_from_list(&queue->tx_pend_queue, queue->tx_link)) != 608 TX_LINK_NONE) 609 queue->tx_link[i] = TX_PENDING; 610} 611 612static int xennet_xdp_xmit_one(struct net_device *dev, 613 struct netfront_queue *queue, 614 struct xdp_frame *xdpf) 615{ 616 struct netfront_info *np = netdev_priv(dev); 617 struct netfront_stats *tx_stats = this_cpu_ptr(np->tx_stats); 618 struct xennet_gnttab_make_txreq info = { 619 .queue = queue, 620 .skb = NULL, 621 .page = virt_to_page(xdpf->data), 622 }; 623 int notify; 624 625 xennet_make_first_txreq(&info, 626 offset_in_page(xdpf->data), 627 xdpf->len); 628 629 xennet_mark_tx_pending(queue); 630 631 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->tx, notify); 632 if (notify) 633 notify_remote_via_irq(queue->tx_irq); 634 635 u64_stats_update_begin(&tx_stats->syncp); 636 tx_stats->bytes += xdpf->len; 637 tx_stats->packets++; 638 u64_stats_update_end(&tx_stats->syncp); 639 640 xennet_tx_buf_gc(queue); 641 642 return 0; 643} 644 645static int xennet_xdp_xmit(struct net_device *dev, int n, 646 struct xdp_frame **frames, u32 flags) 647{ 648 unsigned int num_queues = dev->real_num_tx_queues; 649 struct netfront_info *np = netdev_priv(dev); 650 struct netfront_queue *queue = NULL; 651 unsigned long irq_flags; 652 int nxmit = 0; 653 int i; 654 655 if (unlikely(np->broken)) 656 return -ENODEV; 657 if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK)) 658 return -EINVAL; 659 660 queue = &np->queues[smp_processor_id() % num_queues]; 661 662 spin_lock_irqsave(&queue->tx_lock, irq_flags); 663 for (i = 0; i < n; i++) { 664 struct xdp_frame *xdpf = frames[i]; 665 666 if (!xdpf) 667 continue; 668 if (xennet_xdp_xmit_one(dev, queue, xdpf)) 669 break; 670 nxmit++; 671 } 672 spin_unlock_irqrestore(&queue->tx_lock, irq_flags); 673 674 return nxmit; 675} 676 677static struct sk_buff *bounce_skb(const struct sk_buff *skb) 678{ 679 unsigned int headerlen = skb_headroom(skb); 680 /* Align size to allocate full pages and avoid contiguous data leaks */ 681 unsigned int size = ALIGN(skb_end_offset(skb) + skb->data_len, 682 XEN_PAGE_SIZE); 683 struct sk_buff *n = alloc_skb(size, GFP_ATOMIC | __GFP_ZERO); 684 685 if (!n) 686 return NULL; 687 688 if (!IS_ALIGNED((uintptr_t)n->head, XEN_PAGE_SIZE)) { 689 WARN_ONCE(1, "misaligned skb allocated\n"); 690 kfree_skb(n); 691 return NULL; 692 } 693 694 /* Set the data pointer */ 695 skb_reserve(n, headerlen); 696 /* Set the tail pointer and length */ 697 skb_put(n, skb->len); 698 699 BUG_ON(skb_copy_bits(skb, -headerlen, n->head, headerlen + skb->len)); 700 701 skb_copy_header(n, skb); 702 return n; 703} 704 705#define MAX_XEN_SKB_FRAGS (65536 / XEN_PAGE_SIZE + 1) 706 707static netdev_tx_t xennet_start_xmit(struct sk_buff *skb, struct net_device *dev) 708{ 709 struct netfront_info *np = netdev_priv(dev); 710 struct netfront_stats *tx_stats = this_cpu_ptr(np->tx_stats); 711 struct xen_netif_tx_request *first_tx; 712 unsigned int i; 713 int notify; 714 int slots; 715 struct page *page; 716 unsigned int offset; 717 unsigned int len; 718 unsigned long flags; 719 struct netfront_queue *queue = NULL; 720 struct xennet_gnttab_make_txreq info = { }; 721 unsigned int num_queues = dev->real_num_tx_queues; 722 u16 queue_index; 723 struct sk_buff *nskb; 724 725 /* Drop the packet if no queues are set up */ 726 if (num_queues < 1) 727 goto drop; 728 if (unlikely(np->broken)) 729 goto drop; 730 /* Determine which queue to transmit this SKB on */ 731 queue_index = skb_get_queue_mapping(skb); 732 queue = &np->queues[queue_index]; 733 734 /* If skb->len is too big for wire format, drop skb and alert 735 * user about misconfiguration. 736 */ 737 if (unlikely(skb->len > XEN_NETIF_MAX_TX_SIZE)) { 738 net_alert_ratelimited( 739 "xennet: skb->len = %u, too big for wire format\n", 740 skb->len); 741 goto drop; 742 } 743 744 slots = xennet_count_skb_slots(skb); 745 if (unlikely(slots > MAX_XEN_SKB_FRAGS + 1)) { 746 net_dbg_ratelimited("xennet: skb rides the rocket: %d slots, %d bytes\n", 747 slots, skb->len); 748 if (skb_linearize(skb)) 749 goto drop; 750 } 751 752 page = virt_to_page(skb->data); 753 offset = offset_in_page(skb->data); 754 755 /* The first req should be at least ETH_HLEN size or the packet will be 756 * dropped by netback. 757 * 758 * If the backend is not trusted bounce all data to zeroed pages to 759 * avoid exposing contiguous data on the granted page not belonging to 760 * the skb. 761 */ 762 if (np->bounce || unlikely(PAGE_SIZE - offset < ETH_HLEN)) { 763 nskb = bounce_skb(skb); 764 if (!nskb) 765 goto drop; 766 dev_consume_skb_any(skb); 767 skb = nskb; 768 page = virt_to_page(skb->data); 769 offset = offset_in_page(skb->data); 770 } 771 772 len = skb_headlen(skb); 773 774 spin_lock_irqsave(&queue->tx_lock, flags); 775 776 if (unlikely(!netif_carrier_ok(dev) || 777 (slots > 1 && !xennet_can_sg(dev)) || 778 netif_needs_gso(skb, netif_skb_features(skb)))) { 779 spin_unlock_irqrestore(&queue->tx_lock, flags); 780 goto drop; 781 } 782 783 /* First request for the linear area. */ 784 info.queue = queue; 785 info.skb = skb; 786 info.page = page; 787 first_tx = xennet_make_first_txreq(&info, offset, len); 788 offset += info.tx_local.size; 789 if (offset == PAGE_SIZE) { 790 page++; 791 offset = 0; 792 } 793 len -= info.tx_local.size; 794 795 if (skb->ip_summed == CHECKSUM_PARTIAL) 796 /* local packet? */ 797 first_tx->flags |= XEN_NETTXF_csum_blank | 798 XEN_NETTXF_data_validated; 799 else if (skb->ip_summed == CHECKSUM_UNNECESSARY) 800 /* remote but checksummed. */ 801 first_tx->flags |= XEN_NETTXF_data_validated; 802 803 /* Optional extra info after the first request. */ 804 if (skb_shinfo(skb)->gso_size) { 805 struct xen_netif_extra_info *gso; 806 807 gso = (struct xen_netif_extra_info *) 808 RING_GET_REQUEST(&queue->tx, queue->tx.req_prod_pvt++); 809 810 first_tx->flags |= XEN_NETTXF_extra_info; 811 812 gso->u.gso.size = skb_shinfo(skb)->gso_size; 813 gso->u.gso.type = (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6) ? 814 XEN_NETIF_GSO_TYPE_TCPV6 : 815 XEN_NETIF_GSO_TYPE_TCPV4; 816 gso->u.gso.pad = 0; 817 gso->u.gso.features = 0; 818 819 gso->type = XEN_NETIF_EXTRA_TYPE_GSO; 820 gso->flags = 0; 821 } 822 823 /* Requests for the rest of the linear area. */ 824 xennet_make_txreqs(&info, page, offset, len); 825 826 /* Requests for all the frags. */ 827 for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { 828 skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; 829 xennet_make_txreqs(&info, skb_frag_page(frag), 830 skb_frag_off(frag), 831 skb_frag_size(frag)); 832 } 833 834 /* First request has the packet length. */ 835 first_tx->size = skb->len; 836 837 /* timestamp packet in software */ 838 skb_tx_timestamp(skb); 839 840 xennet_mark_tx_pending(queue); 841 842 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->tx, notify); 843 if (notify) 844 notify_remote_via_irq(queue->tx_irq); 845 846 u64_stats_update_begin(&tx_stats->syncp); 847 tx_stats->bytes += skb->len; 848 tx_stats->packets++; 849 u64_stats_update_end(&tx_stats->syncp); 850 851 /* Note: It is not safe to access skb after xennet_tx_buf_gc()! */ 852 xennet_tx_buf_gc(queue); 853 854 if (!netfront_tx_slot_available(queue)) 855 netif_tx_stop_queue(netdev_get_tx_queue(dev, queue->id)); 856 857 spin_unlock_irqrestore(&queue->tx_lock, flags); 858 859 return NETDEV_TX_OK; 860 861 drop: 862 dev->stats.tx_dropped++; 863 dev_kfree_skb_any(skb); 864 return NETDEV_TX_OK; 865} 866 867static int xennet_close(struct net_device *dev) 868{ 869 struct netfront_info *np = netdev_priv(dev); 870 unsigned int num_queues = dev->real_num_tx_queues; 871 unsigned int i; 872 struct netfront_queue *queue; 873 netif_tx_stop_all_queues(np->netdev); 874 for (i = 0; i < num_queues; ++i) { 875 queue = &np->queues[i]; 876 napi_disable(&queue->napi); 877 } 878 return 0; 879} 880 881static void xennet_destroy_queues(struct netfront_info *info) 882{ 883 unsigned int i; 884 885 for (i = 0; i < info->netdev->real_num_tx_queues; i++) { 886 struct netfront_queue *queue = &info->queues[i]; 887 888 if (netif_running(info->netdev)) 889 napi_disable(&queue->napi); 890 netif_napi_del(&queue->napi); 891 } 892 893 kfree(info->queues); 894 info->queues = NULL; 895} 896 897static void xennet_uninit(struct net_device *dev) 898{ 899 struct netfront_info *np = netdev_priv(dev); 900 xennet_destroy_queues(np); 901} 902 903static void xennet_set_rx_rsp_cons(struct netfront_queue *queue, RING_IDX val) 904{ 905 unsigned long flags; 906 907 spin_lock_irqsave(&queue->rx_cons_lock, flags); 908 queue->rx.rsp_cons = val; 909 queue->rx_rsp_unconsumed = XEN_RING_NR_UNCONSUMED_RESPONSES(&queue->rx); 910 spin_unlock_irqrestore(&queue->rx_cons_lock, flags); 911} 912 913static void xennet_move_rx_slot(struct netfront_queue *queue, struct sk_buff *skb, 914 grant_ref_t ref) 915{ 916 int new = xennet_rxidx(queue->rx.req_prod_pvt); 917 918 BUG_ON(queue->rx_skbs[new]); 919 queue->rx_skbs[new] = skb; 920 queue->grant_rx_ref[new] = ref; 921 RING_GET_REQUEST(&queue->rx, queue->rx.req_prod_pvt)->id = new; 922 RING_GET_REQUEST(&queue->rx, queue->rx.req_prod_pvt)->gref = ref; 923 queue->rx.req_prod_pvt++; 924} 925 926static int xennet_get_extras(struct netfront_queue *queue, 927 struct xen_netif_extra_info *extras, 928 RING_IDX rp) 929 930{ 931 struct xen_netif_extra_info extra; 932 struct device *dev = &queue->info->netdev->dev; 933 RING_IDX cons = queue->rx.rsp_cons; 934 int err = 0; 935 936 do { 937 struct sk_buff *skb; 938 grant_ref_t ref; 939 940 if (unlikely(cons + 1 == rp)) { 941 if (net_ratelimit()) 942 dev_warn(dev, "Missing extra info\n"); 943 err = -EBADR; 944 break; 945 } 946 947 RING_COPY_RESPONSE(&queue->rx, ++cons, &extra); 948 949 if (unlikely(!extra.type || 950 extra.type >= XEN_NETIF_EXTRA_TYPE_MAX)) { 951 if (net_ratelimit()) 952 dev_warn(dev, "Invalid extra type: %d\n", 953 extra.type); 954 err = -EINVAL; 955 } else { 956 extras[extra.type - 1] = extra; 957 } 958 959 skb = xennet_get_rx_skb(queue, cons); 960 ref = xennet_get_rx_ref(queue, cons); 961 xennet_move_rx_slot(queue, skb, ref); 962 } while (extra.flags & XEN_NETIF_EXTRA_FLAG_MORE); 963 964 xennet_set_rx_rsp_cons(queue, cons); 965 return err; 966} 967 968static u32 xennet_run_xdp(struct netfront_queue *queue, struct page *pdata, 969 struct xen_netif_rx_response *rx, struct bpf_prog *prog, 970 struct xdp_buff *xdp, bool *need_xdp_flush) 971{ 972 struct xdp_frame *xdpf; 973 u32 len = rx->status; 974 u32 act; 975 int err; 976 977 xdp_init_buff(xdp, XEN_PAGE_SIZE - XDP_PACKET_HEADROOM, 978 &queue->xdp_rxq); 979 xdp_prepare_buff(xdp, page_address(pdata), XDP_PACKET_HEADROOM, 980 len, false); 981 982 act = bpf_prog_run_xdp(prog, xdp); 983 switch (act) { 984 case XDP_TX: 985 get_page(pdata); 986 xdpf = xdp_convert_buff_to_frame(xdp); 987 err = xennet_xdp_xmit(queue->info->netdev, 1, &xdpf, 0); 988 if (unlikely(!err)) 989 xdp_return_frame_rx_napi(xdpf); 990 else if (unlikely(err < 0)) 991 trace_xdp_exception(queue->info->netdev, prog, act); 992 break; 993 case XDP_REDIRECT: 994 get_page(pdata); 995 err = xdp_do_redirect(queue->info->netdev, xdp, prog); 996 *need_xdp_flush = true; 997 if (unlikely(err)) 998 trace_xdp_exception(queue->info->netdev, prog, act); 999 break; 1000 case XDP_PASS: 1001 case XDP_DROP: 1002 break; 1003 1004 case XDP_ABORTED: 1005 trace_xdp_exception(queue->info->netdev, prog, act); 1006 break; 1007 1008 default: 1009 bpf_warn_invalid_xdp_action(queue->info->netdev, prog, act); 1010 } 1011 1012 return act; 1013} 1014 1015static int xennet_get_responses(struct netfront_queue *queue, 1016 struct netfront_rx_info *rinfo, RING_IDX rp, 1017 struct sk_buff_head *list, 1018 bool *need_xdp_flush) 1019{ 1020 struct xen_netif_rx_response *rx = &rinfo->rx, rx_local; 1021 int max = XEN_NETIF_NR_SLOTS_MIN + (rx->status <= RX_COPY_THRESHOLD); 1022 RING_IDX cons = queue->rx.rsp_cons; 1023 struct sk_buff *skb = xennet_get_rx_skb(queue, cons); 1024 struct xen_netif_extra_info *extras = rinfo->extras; 1025 grant_ref_t ref = xennet_get_rx_ref(queue, cons); 1026 struct device *dev = &queue->info->netdev->dev; 1027 struct bpf_prog *xdp_prog; 1028 struct xdp_buff xdp; 1029 int slots = 1; 1030 int err = 0; 1031 u32 verdict; 1032 1033 if (rx->flags & XEN_NETRXF_extra_info) { 1034 err = xennet_get_extras(queue, extras, rp); 1035 if (!err) { 1036 if (extras[XEN_NETIF_EXTRA_TYPE_XDP - 1].type) { 1037 struct xen_netif_extra_info *xdp; 1038 1039 xdp = &extras[XEN_NETIF_EXTRA_TYPE_XDP - 1]; 1040 rx->offset = xdp->u.xdp.headroom; 1041 } 1042 } 1043 cons = queue->rx.rsp_cons; 1044 } 1045 1046 for (;;) { 1047 /* 1048 * This definitely indicates a bug, either in this driver or in 1049 * the backend driver. In future this should flag the bad 1050 * situation to the system controller to reboot the backend. 1051 */ 1052 if (ref == INVALID_GRANT_REF) { 1053 if (net_ratelimit()) 1054 dev_warn(dev, "Bad rx response id %d.\n", 1055 rx->id); 1056 err = -EINVAL; 1057 goto next; 1058 } 1059 1060 if (unlikely(rx->status < 0 || 1061 rx->offset + rx->status > XEN_PAGE_SIZE)) { 1062 if (net_ratelimit()) 1063 dev_warn(dev, "rx->offset: %u, size: %d\n", 1064 rx->offset, rx->status); 1065 xennet_move_rx_slot(queue, skb, ref); 1066 err = -EINVAL; 1067 goto next; 1068 } 1069 1070 if (!gnttab_end_foreign_access_ref(ref)) { 1071 dev_alert(dev, 1072 "Grant still in use by backend domain\n"); 1073 queue->info->broken = true; 1074 dev_alert(dev, "Disabled for further use\n"); 1075 return -EINVAL; 1076 } 1077 1078 gnttab_release_grant_reference(&queue->gref_rx_head, ref); 1079 1080 rcu_read_lock(); 1081 xdp_prog = rcu_dereference(queue->xdp_prog); 1082 if (xdp_prog) { 1083 if (!(rx->flags & XEN_NETRXF_more_data)) { 1084 /* currently only a single page contains data */ 1085 verdict = xennet_run_xdp(queue, 1086 skb_frag_page(&skb_shinfo(skb)->frags[0]), 1087 rx, xdp_prog, &xdp, need_xdp_flush); 1088 if (verdict != XDP_PASS) 1089 err = -EINVAL; 1090 } else { 1091 /* drop the frame */ 1092 err = -EINVAL; 1093 } 1094 } 1095 rcu_read_unlock(); 1096 1097 __skb_queue_tail(list, skb); 1098 1099next: 1100 if (!(rx->flags & XEN_NETRXF_more_data)) 1101 break; 1102 1103 if (cons + slots == rp) { 1104 if (net_ratelimit()) 1105 dev_warn(dev, "Need more slots\n"); 1106 err = -ENOENT; 1107 break; 1108 } 1109 1110 RING_COPY_RESPONSE(&queue->rx, cons + slots, &rx_local); 1111 rx = &rx_local; 1112 skb = xennet_get_rx_skb(queue, cons + slots); 1113 ref = xennet_get_rx_ref(queue, cons + slots); 1114 slots++; 1115 } 1116 1117 if (unlikely(slots > max)) { 1118 if (net_ratelimit()) 1119 dev_warn(dev, "Too many slots\n"); 1120 err = -E2BIG; 1121 } 1122 1123 if (unlikely(err)) 1124 xennet_set_rx_rsp_cons(queue, cons + slots); 1125 1126 return err; 1127} 1128 1129static int xennet_set_skb_gso(struct sk_buff *skb, 1130 struct xen_netif_extra_info *gso) 1131{ 1132 if (!gso->u.gso.size) { 1133 if (net_ratelimit()) 1134 pr_warn("GSO size must not be zero\n"); 1135 return -EINVAL; 1136 } 1137 1138 if (gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV4 && 1139 gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV6) { 1140 if (net_ratelimit()) 1141 pr_warn("Bad GSO type %d\n", gso->u.gso.type); 1142 return -EINVAL; 1143 } 1144 1145 skb_shinfo(skb)->gso_size = gso->u.gso.size; 1146 skb_shinfo(skb)->gso_type = 1147 (gso->u.gso.type == XEN_NETIF_GSO_TYPE_TCPV4) ? 1148 SKB_GSO_TCPV4 : 1149 SKB_GSO_TCPV6; 1150 1151 /* Header must be checked, and gso_segs computed. */ 1152 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY; 1153 skb_shinfo(skb)->gso_segs = 0; 1154 1155 return 0; 1156} 1157 1158static int xennet_fill_frags(struct netfront_queue *queue, 1159 struct sk_buff *skb, 1160 struct sk_buff_head *list) 1161{ 1162 RING_IDX cons = queue->rx.rsp_cons; 1163 struct sk_buff *nskb; 1164 1165 while ((nskb = __skb_dequeue(list))) { 1166 struct xen_netif_rx_response rx; 1167 skb_frag_t *nfrag = &skb_shinfo(nskb)->frags[0]; 1168 1169 RING_COPY_RESPONSE(&queue->rx, ++cons, &rx); 1170 1171 if (skb_shinfo(skb)->nr_frags == MAX_SKB_FRAGS) { 1172 unsigned int pull_to = NETFRONT_SKB_CB(skb)->pull_to; 1173 1174 BUG_ON(pull_to < skb_headlen(skb)); 1175 __pskb_pull_tail(skb, pull_to - skb_headlen(skb)); 1176 } 1177 if (unlikely(skb_shinfo(skb)->nr_frags >= MAX_SKB_FRAGS)) { 1178 xennet_set_rx_rsp_cons(queue, 1179 ++cons + skb_queue_len(list)); 1180 kfree_skb(nskb); 1181 return -ENOENT; 1182 } 1183 1184 skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, 1185 skb_frag_page(nfrag), 1186 rx.offset, rx.status, PAGE_SIZE); 1187 1188 skb_shinfo(nskb)->nr_frags = 0; 1189 kfree_skb(nskb); 1190 } 1191 1192 xennet_set_rx_rsp_cons(queue, cons); 1193 1194 return 0; 1195} 1196 1197static int checksum_setup(struct net_device *dev, struct sk_buff *skb) 1198{ 1199 bool recalculate_partial_csum = false; 1200 1201 /* 1202 * A GSO SKB must be CHECKSUM_PARTIAL. However some buggy 1203 * peers can fail to set NETRXF_csum_blank when sending a GSO 1204 * frame. In this case force the SKB to CHECKSUM_PARTIAL and 1205 * recalculate the partial checksum. 1206 */ 1207 if (skb->ip_summed != CHECKSUM_PARTIAL && skb_is_gso(skb)) { 1208 struct netfront_info *np = netdev_priv(dev); 1209 atomic_inc(&np->rx_gso_checksum_fixup); 1210 skb->ip_summed = CHECKSUM_PARTIAL; 1211 recalculate_partial_csum = true; 1212 } 1213 1214 /* A non-CHECKSUM_PARTIAL SKB does not require setup. */ 1215 if (skb->ip_summed != CHECKSUM_PARTIAL) 1216 return 0; 1217 1218 return skb_checksum_setup(skb, recalculate_partial_csum); 1219} 1220 1221static int handle_incoming_queue(struct netfront_queue *queue, 1222 struct sk_buff_head *rxq) 1223{ 1224 struct netfront_stats *rx_stats = this_cpu_ptr(queue->info->rx_stats); 1225 int packets_dropped = 0; 1226 struct sk_buff *skb; 1227 1228 while ((skb = __skb_dequeue(rxq)) != NULL) { 1229 int pull_to = NETFRONT_SKB_CB(skb)->pull_to; 1230 1231 if (pull_to > skb_headlen(skb)) 1232 __pskb_pull_tail(skb, pull_to - skb_headlen(skb)); 1233 1234 /* Ethernet work: Delayed to here as it peeks the header. */ 1235 skb->protocol = eth_type_trans(skb, queue->info->netdev); 1236 skb_reset_network_header(skb); 1237 1238 if (checksum_setup(queue->info->netdev, skb)) { 1239 kfree_skb(skb); 1240 packets_dropped++; 1241 queue->info->netdev->stats.rx_errors++; 1242 continue; 1243 } 1244 1245 u64_stats_update_begin(&rx_stats->syncp); 1246 rx_stats->packets++; 1247 rx_stats->bytes += skb->len; 1248 u64_stats_update_end(&rx_stats->syncp); 1249 1250 /* Pass it up. */ 1251 napi_gro_receive(&queue->napi, skb); 1252 } 1253 1254 return packets_dropped; 1255} 1256 1257static int xennet_poll(struct napi_struct *napi, int budget) 1258{ 1259 struct netfront_queue *queue = container_of(napi, struct netfront_queue, napi); 1260 struct net_device *dev = queue->info->netdev; 1261 struct sk_buff *skb; 1262 struct netfront_rx_info rinfo; 1263 struct xen_netif_rx_response *rx = &rinfo.rx; 1264 struct xen_netif_extra_info *extras = rinfo.extras; 1265 RING_IDX i, rp; 1266 int work_done; 1267 struct sk_buff_head rxq; 1268 struct sk_buff_head errq; 1269 struct sk_buff_head tmpq; 1270 int err; 1271 bool need_xdp_flush = false; 1272 1273 spin_lock(&queue->rx_lock); 1274 1275 skb_queue_head_init(&rxq); 1276 skb_queue_head_init(&errq); 1277 skb_queue_head_init(&tmpq); 1278 1279 rp = queue->rx.sring->rsp_prod; 1280 if (RING_RESPONSE_PROD_OVERFLOW(&queue->rx, rp)) { 1281 dev_alert(&dev->dev, "Illegal number of responses %u\n", 1282 rp - queue->rx.rsp_cons); 1283 queue->info->broken = true; 1284 spin_unlock(&queue->rx_lock); 1285 return 0; 1286 } 1287 rmb(); /* Ensure we see queued responses up to 'rp'. */ 1288 1289 i = queue->rx.rsp_cons; 1290 work_done = 0; 1291 while ((i != rp) && (work_done < budget)) { 1292 RING_COPY_RESPONSE(&queue->rx, i, rx); 1293 memset(extras, 0, sizeof(rinfo.extras)); 1294 1295 err = xennet_get_responses(queue, &rinfo, rp, &tmpq, 1296 &need_xdp_flush); 1297 1298 if (unlikely(err)) { 1299 if (queue->info->broken) { 1300 spin_unlock(&queue->rx_lock); 1301 return 0; 1302 } 1303err: 1304 while ((skb = __skb_dequeue(&tmpq))) 1305 __skb_queue_tail(&errq, skb); 1306 dev->stats.rx_errors++; 1307 i = queue->rx.rsp_cons; 1308 continue; 1309 } 1310 1311 skb = __skb_dequeue(&tmpq); 1312 1313 if (extras[XEN_NETIF_EXTRA_TYPE_GSO - 1].type) { 1314 struct xen_netif_extra_info *gso; 1315 gso = &extras[XEN_NETIF_EXTRA_TYPE_GSO - 1]; 1316 1317 if (unlikely(xennet_set_skb_gso(skb, gso))) { 1318 __skb_queue_head(&tmpq, skb); 1319 xennet_set_rx_rsp_cons(queue, 1320 queue->rx.rsp_cons + 1321 skb_queue_len(&tmpq)); 1322 goto err; 1323 } 1324 } 1325 1326 NETFRONT_SKB_CB(skb)->pull_to = rx->status; 1327 if (NETFRONT_SKB_CB(skb)->pull_to > RX_COPY_THRESHOLD) 1328 NETFRONT_SKB_CB(skb)->pull_to = RX_COPY_THRESHOLD; 1329 1330 skb_frag_off_set(&skb_shinfo(skb)->frags[0], rx->offset); 1331 skb_frag_size_set(&skb_shinfo(skb)->frags[0], rx->status); 1332 skb->data_len = rx->status; 1333 skb->len += rx->status; 1334 1335 if (unlikely(xennet_fill_frags(queue, skb, &tmpq))) 1336 goto err; 1337 1338 if (rx->flags & XEN_NETRXF_csum_blank) 1339 skb->ip_summed = CHECKSUM_PARTIAL; 1340 else if (rx->flags & XEN_NETRXF_data_validated) 1341 skb->ip_summed = CHECKSUM_UNNECESSARY; 1342 1343 __skb_queue_tail(&rxq, skb); 1344 1345 i = queue->rx.rsp_cons + 1; 1346 xennet_set_rx_rsp_cons(queue, i); 1347 work_done++; 1348 } 1349 if (need_xdp_flush) 1350 xdp_do_flush(); 1351 1352 __skb_queue_purge(&errq); 1353 1354 work_done -= handle_incoming_queue(queue, &rxq); 1355 1356 xennet_alloc_rx_buffers(queue); 1357 1358 if (work_done < budget) { 1359 int more_to_do = 0; 1360 1361 napi_complete_done(napi, work_done); 1362 1363 RING_FINAL_CHECK_FOR_RESPONSES(&queue->rx, more_to_do); 1364 if (more_to_do) 1365 napi_schedule(napi); 1366 } 1367 1368 spin_unlock(&queue->rx_lock); 1369 1370 return work_done; 1371} 1372 1373static int xennet_change_mtu(struct net_device *dev, int mtu) 1374{ 1375 int max = xennet_can_sg(dev) ? XEN_NETIF_MAX_TX_SIZE : ETH_DATA_LEN; 1376 1377 if (mtu > max) 1378 return -EINVAL; 1379 dev->mtu = mtu; 1380 return 0; 1381} 1382 1383static void xennet_get_stats64(struct net_device *dev, 1384 struct rtnl_link_stats64 *tot) 1385{ 1386 struct netfront_info *np = netdev_priv(dev); 1387 int cpu; 1388 1389 for_each_possible_cpu(cpu) { 1390 struct netfront_stats *rx_stats = per_cpu_ptr(np->rx_stats, cpu); 1391 struct netfront_stats *tx_stats = per_cpu_ptr(np->tx_stats, cpu); 1392 u64 rx_packets, rx_bytes, tx_packets, tx_bytes; 1393 unsigned int start; 1394 1395 do { 1396 start = u64_stats_fetch_begin(&tx_stats->syncp); 1397 tx_packets = tx_stats->packets; 1398 tx_bytes = tx_stats->bytes; 1399 } while (u64_stats_fetch_retry(&tx_stats->syncp, start)); 1400 1401 do { 1402 start = u64_stats_fetch_begin(&rx_stats->syncp); 1403 rx_packets = rx_stats->packets; 1404 rx_bytes = rx_stats->bytes; 1405 } while (u64_stats_fetch_retry(&rx_stats->syncp, start)); 1406 1407 tot->rx_packets += rx_packets; 1408 tot->tx_packets += tx_packets; 1409 tot->rx_bytes += rx_bytes; 1410 tot->tx_bytes += tx_bytes; 1411 } 1412 1413 tot->rx_errors = dev->stats.rx_errors; 1414 tot->tx_dropped = dev->stats.tx_dropped; 1415} 1416 1417static void xennet_release_tx_bufs(struct netfront_queue *queue) 1418{ 1419 struct sk_buff *skb; 1420 int i; 1421 1422 for (i = 0; i < NET_TX_RING_SIZE; i++) { 1423 /* Skip over entries which are actually freelist references */ 1424 if (!queue->tx_skbs[i]) 1425 continue; 1426 1427 skb = queue->tx_skbs[i]; 1428 queue->tx_skbs[i] = NULL; 1429 get_page(queue->grant_tx_page[i]); 1430 gnttab_end_foreign_access(queue->grant_tx_ref[i], 1431 queue->grant_tx_page[i]); 1432 queue->grant_tx_page[i] = NULL; 1433 queue->grant_tx_ref[i] = INVALID_GRANT_REF; 1434 add_id_to_list(&queue->tx_skb_freelist, queue->tx_link, i); 1435 dev_kfree_skb_irq(skb); 1436 } 1437} 1438 1439static void xennet_release_rx_bufs(struct netfront_queue *queue) 1440{ 1441 int id, ref; 1442 1443 spin_lock_bh(&queue->rx_lock); 1444 1445 for (id = 0; id < NET_RX_RING_SIZE; id++) { 1446 struct sk_buff *skb; 1447 struct page *page; 1448 1449 skb = queue->rx_skbs[id]; 1450 if (!skb) 1451 continue; 1452 1453 ref = queue->grant_rx_ref[id]; 1454 if (ref == INVALID_GRANT_REF) 1455 continue; 1456 1457 page = skb_frag_page(&skb_shinfo(skb)->frags[0]); 1458 1459 /* gnttab_end_foreign_access() needs a page ref until 1460 * foreign access is ended (which may be deferred). 1461 */ 1462 get_page(page); 1463 gnttab_end_foreign_access(ref, page); 1464 queue->grant_rx_ref[id] = INVALID_GRANT_REF; 1465 1466 kfree_skb(skb); 1467 } 1468 1469 spin_unlock_bh(&queue->rx_lock); 1470} 1471 1472static netdev_features_t xennet_fix_features(struct net_device *dev, 1473 netdev_features_t features) 1474{ 1475 struct netfront_info *np = netdev_priv(dev); 1476 1477 if (features & NETIF_F_SG && 1478 !xenbus_read_unsigned(np->xbdev->otherend, "feature-sg", 0)) 1479 features &= ~NETIF_F_SG; 1480 1481 if (features & NETIF_F_IPV6_CSUM && 1482 !xenbus_read_unsigned(np->xbdev->otherend, 1483 "feature-ipv6-csum-offload", 0)) 1484 features &= ~NETIF_F_IPV6_CSUM; 1485 1486 if (features & NETIF_F_TSO && 1487 !xenbus_read_unsigned(np->xbdev->otherend, "feature-gso-tcpv4", 0)) 1488 features &= ~NETIF_F_TSO; 1489 1490 if (features & NETIF_F_TSO6 && 1491 !xenbus_read_unsigned(np->xbdev->otherend, "feature-gso-tcpv6", 0)) 1492 features &= ~NETIF_F_TSO6; 1493 1494 return features; 1495} 1496 1497static int xennet_set_features(struct net_device *dev, 1498 netdev_features_t features) 1499{ 1500 if (!(features & NETIF_F_SG) && dev->mtu > ETH_DATA_LEN) { 1501 netdev_info(dev, "Reducing MTU because no SG offload"); 1502 dev->mtu = ETH_DATA_LEN; 1503 } 1504 1505 return 0; 1506} 1507 1508static bool xennet_handle_tx(struct netfront_queue *queue, unsigned int *eoi) 1509{ 1510 unsigned long flags; 1511 1512 if (unlikely(queue->info->broken)) 1513 return false; 1514 1515 spin_lock_irqsave(&queue->tx_lock, flags); 1516 if (xennet_tx_buf_gc(queue)) 1517 *eoi = 0; 1518 spin_unlock_irqrestore(&queue->tx_lock, flags); 1519 1520 return true; 1521} 1522 1523static irqreturn_t xennet_tx_interrupt(int irq, void *dev_id) 1524{ 1525 unsigned int eoiflag = XEN_EOI_FLAG_SPURIOUS; 1526 1527 if (likely(xennet_handle_tx(dev_id, &eoiflag))) 1528 xen_irq_lateeoi(irq, eoiflag); 1529 1530 return IRQ_HANDLED; 1531} 1532 1533static bool xennet_handle_rx(struct netfront_queue *queue, unsigned int *eoi) 1534{ 1535 unsigned int work_queued; 1536 unsigned long flags; 1537 1538 if (unlikely(queue->info->broken)) 1539 return false; 1540 1541 spin_lock_irqsave(&queue->rx_cons_lock, flags); 1542 work_queued = XEN_RING_NR_UNCONSUMED_RESPONSES(&queue->rx); 1543 if (work_queued > queue->rx_rsp_unconsumed) { 1544 queue->rx_rsp_unconsumed = work_queued; 1545 *eoi = 0; 1546 } else if (unlikely(work_queued < queue->rx_rsp_unconsumed)) { 1547 const struct device *dev = &queue->info->netdev->dev; 1548 1549 spin_unlock_irqrestore(&queue->rx_cons_lock, flags); 1550 dev_alert(dev, "RX producer index going backwards\n"); 1551 dev_alert(dev, "Disabled for further use\n"); 1552 queue->info->broken = true; 1553 return false; 1554 } 1555 spin_unlock_irqrestore(&queue->rx_cons_lock, flags); 1556 1557 if (likely(netif_carrier_ok(queue->info->netdev) && work_queued)) 1558 napi_schedule(&queue->napi); 1559 1560 return true; 1561} 1562 1563static irqreturn_t xennet_rx_interrupt(int irq, void *dev_id) 1564{ 1565 unsigned int eoiflag = XEN_EOI_FLAG_SPURIOUS; 1566 1567 if (likely(xennet_handle_rx(dev_id, &eoiflag))) 1568 xen_irq_lateeoi(irq, eoiflag); 1569 1570 return IRQ_HANDLED; 1571} 1572 1573static irqreturn_t xennet_interrupt(int irq, void *dev_id) 1574{ 1575 unsigned int eoiflag = XEN_EOI_FLAG_SPURIOUS; 1576 1577 if (xennet_handle_tx(dev_id, &eoiflag) && 1578 xennet_handle_rx(dev_id, &eoiflag)) 1579 xen_irq_lateeoi(irq, eoiflag); 1580 1581 return IRQ_HANDLED; 1582} 1583 1584#ifdef CONFIG_NET_POLL_CONTROLLER 1585static void xennet_poll_controller(struct net_device *dev) 1586{ 1587 /* Poll each queue */ 1588 struct netfront_info *info = netdev_priv(dev); 1589 unsigned int num_queues = dev->real_num_tx_queues; 1590 unsigned int i; 1591 1592 if (info->broken) 1593 return; 1594 1595 for (i = 0; i < num_queues; ++i) 1596 xennet_interrupt(0, &info->queues[i]); 1597} 1598#endif 1599 1600#define NETBACK_XDP_HEADROOM_DISABLE 0 1601#define NETBACK_XDP_HEADROOM_ENABLE 1 1602 1603static int talk_to_netback_xdp(struct netfront_info *np, int xdp) 1604{ 1605 int err; 1606 unsigned short headroom; 1607 1608 headroom = xdp ? XDP_PACKET_HEADROOM : 0; 1609 err = xenbus_printf(XBT_NIL, np->xbdev->nodename, 1610 "xdp-headroom", "%hu", 1611 headroom); 1612 if (err) 1613 pr_warn("Error writing xdp-headroom\n"); 1614 1615 return err; 1616} 1617 1618static int xennet_xdp_set(struct net_device *dev, struct bpf_prog *prog, 1619 struct netlink_ext_ack *extack) 1620{ 1621 unsigned long max_mtu = XEN_PAGE_SIZE - XDP_PACKET_HEADROOM; 1622 struct netfront_info *np = netdev_priv(dev); 1623 struct bpf_prog *old_prog; 1624 unsigned int i, err; 1625 1626 if (dev->mtu > max_mtu) { 1627 netdev_warn(dev, "XDP requires MTU less than %lu\n", max_mtu); 1628 return -EINVAL; 1629 } 1630 1631 if (!np->netback_has_xdp_headroom) 1632 return 0; 1633 1634 xenbus_switch_state(np->xbdev, XenbusStateReconfiguring); 1635 1636 err = talk_to_netback_xdp(np, prog ? NETBACK_XDP_HEADROOM_ENABLE : 1637 NETBACK_XDP_HEADROOM_DISABLE); 1638 if (err) 1639 return err; 1640 1641 /* avoid the race with XDP headroom adjustment */ 1642 wait_event(module_wq, 1643 xenbus_read_driver_state(np->xbdev->otherend) == 1644 XenbusStateReconfigured); 1645 np->netfront_xdp_enabled = true; 1646 1647 old_prog = rtnl_dereference(np->queues[0].xdp_prog); 1648 1649 if (prog) 1650 bpf_prog_add(prog, dev->real_num_tx_queues); 1651 1652 for (i = 0; i < dev->real_num_tx_queues; ++i) 1653 rcu_assign_pointer(np->queues[i].xdp_prog, prog); 1654 1655 if (old_prog) 1656 for (i = 0; i < dev->real_num_tx_queues; ++i) 1657 bpf_prog_put(old_prog); 1658 1659 xenbus_switch_state(np->xbdev, XenbusStateConnected); 1660 1661 return 0; 1662} 1663 1664static int xennet_xdp(struct net_device *dev, struct netdev_bpf *xdp) 1665{ 1666 struct netfront_info *np = netdev_priv(dev); 1667 1668 if (np->broken) 1669 return -ENODEV; 1670 1671 switch (xdp->command) { 1672 case XDP_SETUP_PROG: 1673 return xennet_xdp_set(dev, xdp->prog, xdp->extack); 1674 default: 1675 return -EINVAL; 1676 } 1677} 1678 1679static const struct net_device_ops xennet_netdev_ops = { 1680 .ndo_uninit = xennet_uninit, 1681 .ndo_open = xennet_open, 1682 .ndo_stop = xennet_close, 1683 .ndo_start_xmit = xennet_start_xmit, 1684 .ndo_change_mtu = xennet_change_mtu, 1685 .ndo_get_stats64 = xennet_get_stats64, 1686 .ndo_set_mac_address = eth_mac_addr, 1687 .ndo_validate_addr = eth_validate_addr, 1688 .ndo_fix_features = xennet_fix_features, 1689 .ndo_set_features = xennet_set_features, 1690 .ndo_select_queue = xennet_select_queue, 1691 .ndo_bpf = xennet_xdp, 1692 .ndo_xdp_xmit = xennet_xdp_xmit, 1693#ifdef CONFIG_NET_POLL_CONTROLLER 1694 .ndo_poll_controller = xennet_poll_controller, 1695#endif 1696}; 1697 1698static void xennet_free_netdev(struct net_device *netdev) 1699{ 1700 struct netfront_info *np = netdev_priv(netdev); 1701 1702 free_percpu(np->rx_stats); 1703 free_percpu(np->tx_stats); 1704 free_netdev(netdev); 1705} 1706 1707static struct net_device *xennet_create_dev(struct xenbus_device *dev) 1708{ 1709 int err; 1710 struct net_device *netdev; 1711 struct netfront_info *np; 1712 1713 netdev = alloc_etherdev_mq(sizeof(struct netfront_info), xennet_max_queues); 1714 if (!netdev) 1715 return ERR_PTR(-ENOMEM); 1716 1717 np = netdev_priv(netdev); 1718 np->xbdev = dev; 1719 1720 np->queues = NULL; 1721 1722 err = -ENOMEM; 1723 np->rx_stats = netdev_alloc_pcpu_stats(struct netfront_stats); 1724 if (np->rx_stats == NULL) 1725 goto exit; 1726 np->tx_stats = netdev_alloc_pcpu_stats(struct netfront_stats); 1727 if (np->tx_stats == NULL) 1728 goto exit; 1729 1730 netdev->netdev_ops = &xennet_netdev_ops; 1731 1732 netdev->features = NETIF_F_IP_CSUM | NETIF_F_RXCSUM | 1733 NETIF_F_GSO_ROBUST; 1734 netdev->hw_features = NETIF_F_SG | 1735 NETIF_F_IPV6_CSUM | 1736 NETIF_F_TSO | NETIF_F_TSO6; 1737 1738 /* 1739 * Assume that all hw features are available for now. This set 1740 * will be adjusted by the call to netdev_update_features() in 1741 * xennet_connect() which is the earliest point where we can 1742 * negotiate with the backend regarding supported features. 1743 */ 1744 netdev->features |= netdev->hw_features; 1745 netdev->xdp_features = NETDEV_XDP_ACT_BASIC | NETDEV_XDP_ACT_REDIRECT | 1746 NETDEV_XDP_ACT_NDO_XMIT; 1747 1748 netdev->ethtool_ops = &xennet_ethtool_ops; 1749 netdev->min_mtu = ETH_MIN_MTU; 1750 netdev->max_mtu = XEN_NETIF_MAX_TX_SIZE; 1751 SET_NETDEV_DEV(netdev, &dev->dev); 1752 1753 np->netdev = netdev; 1754 np->netfront_xdp_enabled = false; 1755 1756 netif_carrier_off(netdev); 1757 1758 do { 1759 xenbus_switch_state(dev, XenbusStateInitialising); 1760 err = wait_event_timeout(module_wq, 1761 xenbus_read_driver_state(dev->otherend) != 1762 XenbusStateClosed && 1763 xenbus_read_driver_state(dev->otherend) != 1764 XenbusStateUnknown, XENNET_TIMEOUT); 1765 } while (!err); 1766 1767 return netdev; 1768 1769 exit: 1770 xennet_free_netdev(netdev); 1771 return ERR_PTR(err); 1772} 1773 1774/* 1775 * Entry point to this code when a new device is created. Allocate the basic 1776 * structures and the ring buffers for communication with the backend, and 1777 * inform the backend of the appropriate details for those. 1778 */ 1779static int netfront_probe(struct xenbus_device *dev, 1780 const struct xenbus_device_id *id) 1781{ 1782 int err; 1783 struct net_device *netdev; 1784 struct netfront_info *info; 1785 1786 netdev = xennet_create_dev(dev); 1787 if (IS_ERR(netdev)) { 1788 err = PTR_ERR(netdev); 1789 xenbus_dev_fatal(dev, err, "creating netdev"); 1790 return err; 1791 } 1792 1793 info = netdev_priv(netdev); 1794 dev_set_drvdata(&dev->dev, info); 1795#ifdef CONFIG_SYSFS 1796 info->netdev->sysfs_groups[0] = &xennet_dev_group; 1797#endif 1798 1799 return 0; 1800} 1801 1802static void xennet_end_access(int ref, void *page) 1803{ 1804 /* This frees the page as a side-effect */ 1805 if (ref != INVALID_GRANT_REF) 1806 gnttab_end_foreign_access(ref, virt_to_page(page)); 1807} 1808 1809static void xennet_disconnect_backend(struct netfront_info *info) 1810{ 1811 unsigned int i = 0; 1812 unsigned int num_queues = info->netdev->real_num_tx_queues; 1813 1814 netif_carrier_off(info->netdev); 1815 1816 for (i = 0; i < num_queues && info->queues; ++i) { 1817 struct netfront_queue *queue = &info->queues[i]; 1818 1819 del_timer_sync(&queue->rx_refill_timer); 1820 1821 if (queue->tx_irq && (queue->tx_irq == queue->rx_irq)) 1822 unbind_from_irqhandler(queue->tx_irq, queue); 1823 if (queue->tx_irq && (queue->tx_irq != queue->rx_irq)) { 1824 unbind_from_irqhandler(queue->tx_irq, queue); 1825 unbind_from_irqhandler(queue->rx_irq, queue); 1826 } 1827 queue->tx_evtchn = queue->rx_evtchn = 0; 1828 queue->tx_irq = queue->rx_irq = 0; 1829 1830 if (netif_running(info->netdev)) 1831 napi_synchronize(&queue->napi); 1832 1833 xennet_release_tx_bufs(queue); 1834 xennet_release_rx_bufs(queue); 1835 gnttab_free_grant_references(queue->gref_tx_head); 1836 gnttab_free_grant_references(queue->gref_rx_head); 1837 1838 /* End access and free the pages */ 1839 xennet_end_access(queue->tx_ring_ref, queue->tx.sring); 1840 xennet_end_access(queue->rx_ring_ref, queue->rx.sring); 1841 1842 queue->tx_ring_ref = INVALID_GRANT_REF; 1843 queue->rx_ring_ref = INVALID_GRANT_REF; 1844 queue->tx.sring = NULL; 1845 queue->rx.sring = NULL; 1846 1847 page_pool_destroy(queue->page_pool); 1848 } 1849} 1850 1851/* 1852 * We are reconnecting to the backend, due to a suspend/resume, or a backend 1853 * driver restart. We tear down our netif structure and recreate it, but 1854 * leave the device-layer structures intact so that this is transparent to the 1855 * rest of the kernel. 1856 */ 1857static int netfront_resume(struct xenbus_device *dev) 1858{ 1859 struct netfront_info *info = dev_get_drvdata(&dev->dev); 1860 1861 dev_dbg(&dev->dev, "%s\n", dev->nodename); 1862 1863 netif_tx_lock_bh(info->netdev); 1864 netif_device_detach(info->netdev); 1865 netif_tx_unlock_bh(info->netdev); 1866 1867 xennet_disconnect_backend(info); 1868 1869 rtnl_lock(); 1870 if (info->queues) 1871 xennet_destroy_queues(info); 1872 rtnl_unlock(); 1873 1874 return 0; 1875} 1876 1877static int xen_net_read_mac(struct xenbus_device *dev, u8 mac[]) 1878{ 1879 char *s, *e, *macstr; 1880 int i; 1881 1882 macstr = s = xenbus_read(XBT_NIL, dev->nodename, "mac", NULL); 1883 if (IS_ERR(macstr)) 1884 return PTR_ERR(macstr); 1885 1886 for (i = 0; i < ETH_ALEN; i++) { 1887 mac[i] = simple_strtoul(s, &e, 16); 1888 if ((s == e) || (*e != ((i == ETH_ALEN-1) ? '\0' : ':'))) { 1889 kfree(macstr); 1890 return -ENOENT; 1891 } 1892 s = e+1; 1893 } 1894 1895 kfree(macstr); 1896 return 0; 1897} 1898 1899static int setup_netfront_single(struct netfront_queue *queue) 1900{ 1901 int err; 1902 1903 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->tx_evtchn); 1904 if (err < 0) 1905 goto fail; 1906 1907 err = bind_evtchn_to_irqhandler_lateeoi(queue->tx_evtchn, 1908 xennet_interrupt, 0, 1909 queue->info->netdev->name, 1910 queue); 1911 if (err < 0) 1912 goto bind_fail; 1913 queue->rx_evtchn = queue->tx_evtchn; 1914 queue->rx_irq = queue->tx_irq = err; 1915 1916 return 0; 1917 1918bind_fail: 1919 xenbus_free_evtchn(queue->info->xbdev, queue->tx_evtchn); 1920 queue->tx_evtchn = 0; 1921fail: 1922 return err; 1923} 1924 1925static int setup_netfront_split(struct netfront_queue *queue) 1926{ 1927 int err; 1928 1929 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->tx_evtchn); 1930 if (err < 0) 1931 goto fail; 1932 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->rx_evtchn); 1933 if (err < 0) 1934 goto alloc_rx_evtchn_fail; 1935 1936 snprintf(queue->tx_irq_name, sizeof(queue->tx_irq_name), 1937 "%s-tx", queue->name); 1938 err = bind_evtchn_to_irqhandler_lateeoi(queue->tx_evtchn, 1939 xennet_tx_interrupt, 0, 1940 queue->tx_irq_name, queue); 1941 if (err < 0) 1942 goto bind_tx_fail; 1943 queue->tx_irq = err; 1944 1945 snprintf(queue->rx_irq_name, sizeof(queue->rx_irq_name), 1946 "%s-rx", queue->name); 1947 err = bind_evtchn_to_irqhandler_lateeoi(queue->rx_evtchn, 1948 xennet_rx_interrupt, 0, 1949 queue->rx_irq_name, queue); 1950 if (err < 0) 1951 goto bind_rx_fail; 1952 queue->rx_irq = err; 1953 1954 return 0; 1955 1956bind_rx_fail: 1957 unbind_from_irqhandler(queue->tx_irq, queue); 1958 queue->tx_irq = 0; 1959bind_tx_fail: 1960 xenbus_free_evtchn(queue->info->xbdev, queue->rx_evtchn); 1961 queue->rx_evtchn = 0; 1962alloc_rx_evtchn_fail: 1963 xenbus_free_evtchn(queue->info->xbdev, queue->tx_evtchn); 1964 queue->tx_evtchn = 0; 1965fail: 1966 return err; 1967} 1968 1969static int setup_netfront(struct xenbus_device *dev, 1970 struct netfront_queue *queue, unsigned int feature_split_evtchn) 1971{ 1972 struct xen_netif_tx_sring *txs; 1973 struct xen_netif_rx_sring *rxs; 1974 int err; 1975 1976 queue->tx_ring_ref = INVALID_GRANT_REF; 1977 queue->rx_ring_ref = INVALID_GRANT_REF; 1978 queue->rx.sring = NULL; 1979 queue->tx.sring = NULL; 1980 1981 err = xenbus_setup_ring(dev, GFP_NOIO | __GFP_HIGH, (void **)&txs, 1982 1, &queue->tx_ring_ref); 1983 if (err) 1984 goto fail; 1985 1986 XEN_FRONT_RING_INIT(&queue->tx, txs, XEN_PAGE_SIZE); 1987 1988 err = xenbus_setup_ring(dev, GFP_NOIO | __GFP_HIGH, (void **)&rxs, 1989 1, &queue->rx_ring_ref); 1990 if (err) 1991 goto fail; 1992 1993 XEN_FRONT_RING_INIT(&queue->rx, rxs, XEN_PAGE_SIZE); 1994 1995 if (feature_split_evtchn) 1996 err = setup_netfront_split(queue); 1997 /* setup single event channel if 1998 * a) feature-split-event-channels == 0 1999 * b) feature-split-event-channels == 1 but failed to setup 2000 */ 2001 if (!feature_split_evtchn || err) 2002 err = setup_netfront_single(queue); 2003 2004 if (err) 2005 goto fail; 2006 2007 return 0; 2008 2009 fail: 2010 xenbus_teardown_ring((void **)&queue->rx.sring, 1, &queue->rx_ring_ref); 2011 xenbus_teardown_ring((void **)&queue->tx.sring, 1, &queue->tx_ring_ref); 2012 2013 return err; 2014} 2015 2016/* Queue-specific initialisation 2017 * This used to be done in xennet_create_dev() but must now 2018 * be run per-queue. 2019 */ 2020static int xennet_init_queue(struct netfront_queue *queue) 2021{ 2022 unsigned short i; 2023 int err = 0; 2024 char *devid; 2025 2026 spin_lock_init(&queue->tx_lock); 2027 spin_lock_init(&queue->rx_lock); 2028 spin_lock_init(&queue->rx_cons_lock); 2029 2030 timer_setup(&queue->rx_refill_timer, rx_refill_timeout, 0); 2031 2032 devid = strrchr(queue->info->xbdev->nodename, '/') + 1; 2033 snprintf(queue->name, sizeof(queue->name), "vif%s-q%u", 2034 devid, queue->id); 2035 2036 /* Initialise tx_skb_freelist as a free chain containing every entry. */ 2037 queue->tx_skb_freelist = 0; 2038 queue->tx_pend_queue = TX_LINK_NONE; 2039 for (i = 0; i < NET_TX_RING_SIZE; i++) { 2040 queue->tx_link[i] = i + 1; 2041 queue->grant_tx_ref[i] = INVALID_GRANT_REF; 2042 queue->grant_tx_page[i] = NULL; 2043 } 2044 queue->tx_link[NET_TX_RING_SIZE - 1] = TX_LINK_NONE; 2045 2046 /* Clear out rx_skbs */ 2047 for (i = 0; i < NET_RX_RING_SIZE; i++) { 2048 queue->rx_skbs[i] = NULL; 2049 queue->grant_rx_ref[i] = INVALID_GRANT_REF; 2050 } 2051 2052 /* A grant for every tx ring slot */ 2053 if (gnttab_alloc_grant_references(NET_TX_RING_SIZE, 2054 &queue->gref_tx_head) < 0) { 2055 pr_alert("can't alloc tx grant refs\n"); 2056 err = -ENOMEM; 2057 goto exit; 2058 } 2059 2060 /* A grant for every rx ring slot */ 2061 if (gnttab_alloc_grant_references(NET_RX_RING_SIZE, 2062 &queue->gref_rx_head) < 0) { 2063 pr_alert("can't alloc rx grant refs\n"); 2064 err = -ENOMEM; 2065 goto exit_free_tx; 2066 } 2067 2068 return 0; 2069 2070 exit_free_tx: 2071 gnttab_free_grant_references(queue->gref_tx_head); 2072 exit: 2073 return err; 2074} 2075 2076static int write_queue_xenstore_keys(struct netfront_queue *queue, 2077 struct xenbus_transaction *xbt, int write_hierarchical) 2078{ 2079 /* Write the queue-specific keys into XenStore in the traditional 2080 * way for a single queue, or in a queue subkeys for multiple 2081 * queues. 2082 */ 2083 struct xenbus_device *dev = queue->info->xbdev; 2084 int err; 2085 const char *message; 2086 char *path; 2087 size_t pathsize; 2088 2089 /* Choose the correct place to write the keys */ 2090 if (write_hierarchical) { 2091 pathsize = strlen(dev->nodename) + 10; 2092 path = kzalloc(pathsize, GFP_KERNEL); 2093 if (!path) { 2094 err = -ENOMEM; 2095 message = "out of memory while writing ring references"; 2096 goto error; 2097 } 2098 snprintf(path, pathsize, "%s/queue-%u", 2099 dev->nodename, queue->id); 2100 } else { 2101 path = (char *)dev->nodename; 2102 } 2103 2104 /* Write ring references */ 2105 err = xenbus_printf(*xbt, path, "tx-ring-ref", "%u", 2106 queue->tx_ring_ref); 2107 if (err) { 2108 message = "writing tx-ring-ref"; 2109 goto error; 2110 } 2111 2112 err = xenbus_printf(*xbt, path, "rx-ring-ref", "%u", 2113 queue->rx_ring_ref); 2114 if (err) { 2115 message = "writing rx-ring-ref"; 2116 goto error; 2117 } 2118 2119 /* Write event channels; taking into account both shared 2120 * and split event channel scenarios. 2121 */ 2122 if (queue->tx_evtchn == queue->rx_evtchn) { 2123 /* Shared event channel */ 2124 err = xenbus_printf(*xbt, path, 2125 "event-channel", "%u", queue->tx_evtchn); 2126 if (err) { 2127 message = "writing event-channel"; 2128 goto error; 2129 } 2130 } else { 2131 /* Split event channels */ 2132 err = xenbus_printf(*xbt, path, 2133 "event-channel-tx", "%u", queue->tx_evtchn); 2134 if (err) { 2135 message = "writing event-channel-tx"; 2136 goto error; 2137 } 2138 2139 err = xenbus_printf(*xbt, path, 2140 "event-channel-rx", "%u", queue->rx_evtchn); 2141 if (err) { 2142 message = "writing event-channel-rx"; 2143 goto error; 2144 } 2145 } 2146 2147 if (write_hierarchical) 2148 kfree(path); 2149 return 0; 2150 2151error: 2152 if (write_hierarchical) 2153 kfree(path); 2154 xenbus_dev_fatal(dev, err, "%s", message); 2155 return err; 2156} 2157 2158 2159 2160static int xennet_create_page_pool(struct netfront_queue *queue) 2161{ 2162 int err; 2163 struct page_pool_params pp_params = { 2164 .order = 0, 2165 .flags = 0, 2166 .pool_size = NET_RX_RING_SIZE, 2167 .nid = NUMA_NO_NODE, 2168 .dev = &queue->info->netdev->dev, 2169 .offset = XDP_PACKET_HEADROOM, 2170 .max_len = XEN_PAGE_SIZE - XDP_PACKET_HEADROOM, 2171 }; 2172 2173 queue->page_pool = page_pool_create(&pp_params); 2174 if (IS_ERR(queue->page_pool)) { 2175 err = PTR_ERR(queue->page_pool); 2176 queue->page_pool = NULL; 2177 return err; 2178 } 2179 2180 err = xdp_rxq_info_reg(&queue->xdp_rxq, queue->info->netdev, 2181 queue->id, 0); 2182 if (err) { 2183 netdev_err(queue->info->netdev, "xdp_rxq_info_reg failed\n"); 2184 goto err_free_pp; 2185 } 2186 2187 err = xdp_rxq_info_reg_mem_model(&queue->xdp_rxq, 2188 MEM_TYPE_PAGE_POOL, queue->page_pool); 2189 if (err) { 2190 netdev_err(queue->info->netdev, "xdp_rxq_info_reg_mem_model failed\n"); 2191 goto err_unregister_rxq; 2192 } 2193 return 0; 2194 2195err_unregister_rxq: 2196 xdp_rxq_info_unreg(&queue->xdp_rxq); 2197err_free_pp: 2198 page_pool_destroy(queue->page_pool); 2199 queue->page_pool = NULL; 2200 return err; 2201} 2202 2203static int xennet_create_queues(struct netfront_info *info, 2204 unsigned int *num_queues) 2205{ 2206 unsigned int i; 2207 int ret; 2208 2209 info->queues = kcalloc(*num_queues, sizeof(struct netfront_queue), 2210 GFP_KERNEL); 2211 if (!info->queues) 2212 return -ENOMEM; 2213 2214 for (i = 0; i < *num_queues; i++) { 2215 struct netfront_queue *queue = &info->queues[i]; 2216 2217 queue->id = i; 2218 queue->info = info; 2219 2220 ret = xennet_init_queue(queue); 2221 if (ret < 0) { 2222 dev_warn(&info->xbdev->dev, 2223 "only created %d queues\n", i); 2224 *num_queues = i; 2225 break; 2226 } 2227 2228 /* use page pool recycling instead of buddy allocator */ 2229 ret = xennet_create_page_pool(queue); 2230 if (ret < 0) { 2231 dev_err(&info->xbdev->dev, "can't allocate page pool\n"); 2232 *num_queues = i; 2233 return ret; 2234 } 2235 2236 netif_napi_add(queue->info->netdev, &queue->napi, xennet_poll); 2237 if (netif_running(info->netdev)) 2238 napi_enable(&queue->napi); 2239 } 2240 2241 netif_set_real_num_tx_queues(info->netdev, *num_queues); 2242 2243 if (*num_queues == 0) { 2244 dev_err(&info->xbdev->dev, "no queues\n"); 2245 return -EINVAL; 2246 } 2247 return 0; 2248} 2249 2250/* Common code used when first setting up, and when resuming. */ 2251static int talk_to_netback(struct xenbus_device *dev, 2252 struct netfront_info *info) 2253{ 2254 const char *message; 2255 struct xenbus_transaction xbt; 2256 int err; 2257 unsigned int feature_split_evtchn; 2258 unsigned int i = 0; 2259 unsigned int max_queues = 0; 2260 struct netfront_queue *queue = NULL; 2261 unsigned int num_queues = 1; 2262 u8 addr[ETH_ALEN]; 2263 2264 info->netdev->irq = 0; 2265 2266 /* Check if backend is trusted. */ 2267 info->bounce = !xennet_trusted || 2268 !xenbus_read_unsigned(dev->nodename, "trusted", 1); 2269 2270 /* Check if backend supports multiple queues */ 2271 max_queues = xenbus_read_unsigned(info->xbdev->otherend, 2272 "multi-queue-max-queues", 1); 2273 num_queues = min(max_queues, xennet_max_queues); 2274 2275 /* Check feature-split-event-channels */ 2276 feature_split_evtchn = xenbus_read_unsigned(info->xbdev->otherend, 2277 "feature-split-event-channels", 0); 2278 2279 /* Read mac addr. */ 2280 err = xen_net_read_mac(dev, addr); 2281 if (err) { 2282 xenbus_dev_fatal(dev, err, "parsing %s/mac", dev->nodename); 2283 goto out_unlocked; 2284 } 2285 eth_hw_addr_set(info->netdev, addr); 2286 2287 info->netback_has_xdp_headroom = xenbus_read_unsigned(info->xbdev->otherend, 2288 "feature-xdp-headroom", 0); 2289 if (info->netback_has_xdp_headroom) { 2290 /* set the current xen-netfront xdp state */ 2291 err = talk_to_netback_xdp(info, info->netfront_xdp_enabled ? 2292 NETBACK_XDP_HEADROOM_ENABLE : 2293 NETBACK_XDP_HEADROOM_DISABLE); 2294 if (err) 2295 goto out_unlocked; 2296 } 2297 2298 rtnl_lock(); 2299 if (info->queues) 2300 xennet_destroy_queues(info); 2301 2302 /* For the case of a reconnect reset the "broken" indicator. */ 2303 info->broken = false; 2304 2305 err = xennet_create_queues(info, &num_queues); 2306 if (err < 0) { 2307 xenbus_dev_fatal(dev, err, "creating queues"); 2308 kfree(info->queues); 2309 info->queues = NULL; 2310 goto out; 2311 } 2312 rtnl_unlock(); 2313 2314 /* Create shared ring, alloc event channel -- for each queue */ 2315 for (i = 0; i < num_queues; ++i) { 2316 queue = &info->queues[i]; 2317 err = setup_netfront(dev, queue, feature_split_evtchn); 2318 if (err) 2319 goto destroy_ring; 2320 } 2321 2322again: 2323 err = xenbus_transaction_start(&xbt); 2324 if (err) { 2325 xenbus_dev_fatal(dev, err, "starting transaction"); 2326 goto destroy_ring; 2327 } 2328 2329 if (xenbus_exists(XBT_NIL, 2330 info->xbdev->otherend, "multi-queue-max-queues")) { 2331 /* Write the number of queues */ 2332 err = xenbus_printf(xbt, dev->nodename, 2333 "multi-queue-num-queues", "%u", num_queues); 2334 if (err) { 2335 message = "writing multi-queue-num-queues"; 2336 goto abort_transaction_no_dev_fatal; 2337 } 2338 } 2339 2340 if (num_queues == 1) { 2341 err = write_queue_xenstore_keys(&info->queues[0], &xbt, 0); /* flat */ 2342 if (err) 2343 goto abort_transaction_no_dev_fatal; 2344 } else { 2345 /* Write the keys for each queue */ 2346 for (i = 0; i < num_queues; ++i) { 2347 queue = &info->queues[i]; 2348 err = write_queue_xenstore_keys(queue, &xbt, 1); /* hierarchical */ 2349 if (err) 2350 goto abort_transaction_no_dev_fatal; 2351 } 2352 } 2353 2354 /* The remaining keys are not queue-specific */ 2355 err = xenbus_printf(xbt, dev->nodename, "request-rx-copy", "%u", 2356 1); 2357 if (err) { 2358 message = "writing request-rx-copy"; 2359 goto abort_transaction; 2360 } 2361 2362 err = xenbus_printf(xbt, dev->nodename, "feature-rx-notify", "%d", 1); 2363 if (err) { 2364 message = "writing feature-rx-notify"; 2365 goto abort_transaction; 2366 } 2367 2368 err = xenbus_printf(xbt, dev->nodename, "feature-sg", "%d", 1); 2369 if (err) { 2370 message = "writing feature-sg"; 2371 goto abort_transaction; 2372 } 2373 2374 err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv4", "%d", 1); 2375 if (err) { 2376 message = "writing feature-gso-tcpv4"; 2377 goto abort_transaction; 2378 } 2379 2380 err = xenbus_write(xbt, dev->nodename, "feature-gso-tcpv6", "1"); 2381 if (err) { 2382 message = "writing feature-gso-tcpv6"; 2383 goto abort_transaction; 2384 } 2385 2386 err = xenbus_write(xbt, dev->nodename, "feature-ipv6-csum-offload", 2387 "1"); 2388 if (err) { 2389 message = "writing feature-ipv6-csum-offload"; 2390 goto abort_transaction; 2391 } 2392 2393 err = xenbus_transaction_end(xbt, 0); 2394 if (err) { 2395 if (err == -EAGAIN) 2396 goto again; 2397 xenbus_dev_fatal(dev, err, "completing transaction"); 2398 goto destroy_ring; 2399 } 2400 2401 return 0; 2402 2403 abort_transaction: 2404 xenbus_dev_fatal(dev, err, "%s", message); 2405abort_transaction_no_dev_fatal: 2406 xenbus_transaction_end(xbt, 1); 2407 destroy_ring: 2408 xennet_disconnect_backend(info); 2409 rtnl_lock(); 2410 xennet_destroy_queues(info); 2411 out: 2412 rtnl_unlock(); 2413out_unlocked: 2414 device_unregister(&dev->dev); 2415 return err; 2416} 2417 2418static int xennet_connect(struct net_device *dev) 2419{ 2420 struct netfront_info *np = netdev_priv(dev); 2421 unsigned int num_queues = 0; 2422 int err; 2423 unsigned int j = 0; 2424 struct netfront_queue *queue = NULL; 2425 2426 if (!xenbus_read_unsigned(np->xbdev->otherend, "feature-rx-copy", 0)) { 2427 dev_info(&dev->dev, 2428 "backend does not support copying receive path\n"); 2429 return -ENODEV; 2430 } 2431 2432 err = talk_to_netback(np->xbdev, np); 2433 if (err) 2434 return err; 2435 if (np->netback_has_xdp_headroom) 2436 pr_info("backend supports XDP headroom\n"); 2437 if (np->bounce) 2438 dev_info(&np->xbdev->dev, 2439 "bouncing transmitted data to zeroed pages\n"); 2440 2441 /* talk_to_netback() sets the correct number of queues */ 2442 num_queues = dev->real_num_tx_queues; 2443 2444 if (dev->reg_state == NETREG_UNINITIALIZED) { 2445 err = register_netdev(dev); 2446 if (err) { 2447 pr_warn("%s: register_netdev err=%d\n", __func__, err); 2448 device_unregister(&np->xbdev->dev); 2449 return err; 2450 } 2451 } 2452 2453 rtnl_lock(); 2454 netdev_update_features(dev); 2455 rtnl_unlock(); 2456 2457 /* 2458 * All public and private state should now be sane. Get 2459 * ready to start sending and receiving packets and give the driver 2460 * domain a kick because we've probably just requeued some 2461 * packets. 2462 */ 2463 netif_tx_lock_bh(np->netdev); 2464 netif_device_attach(np->netdev); 2465 netif_tx_unlock_bh(np->netdev); 2466 2467 netif_carrier_on(np->netdev); 2468 for (j = 0; j < num_queues; ++j) { 2469 queue = &np->queues[j]; 2470 2471 notify_remote_via_irq(queue->tx_irq); 2472 if (queue->tx_irq != queue->rx_irq) 2473 notify_remote_via_irq(queue->rx_irq); 2474 2475 spin_lock_bh(&queue->rx_lock); 2476 xennet_alloc_rx_buffers(queue); 2477 spin_unlock_bh(&queue->rx_lock); 2478 } 2479 2480 return 0; 2481} 2482 2483/* 2484 * Callback received when the backend's state changes. 2485 */ 2486static void netback_changed(struct xenbus_device *dev, 2487 enum xenbus_state backend_state) 2488{ 2489 struct netfront_info *np = dev_get_drvdata(&dev->dev); 2490 struct net_device *netdev = np->netdev; 2491 2492 dev_dbg(&dev->dev, "%s\n", xenbus_strstate(backend_state)); 2493 2494 wake_up_all(&module_wq); 2495 2496 switch (backend_state) { 2497 case XenbusStateInitialising: 2498 case XenbusStateInitialised: 2499 case XenbusStateReconfiguring: 2500 case XenbusStateReconfigured: 2501 case XenbusStateUnknown: 2502 break; 2503 2504 case XenbusStateInitWait: 2505 if (dev->state != XenbusStateInitialising) 2506 break; 2507 if (xennet_connect(netdev) != 0) 2508 break; 2509 xenbus_switch_state(dev, XenbusStateConnected); 2510 break; 2511 2512 case XenbusStateConnected: 2513 netdev_notify_peers(netdev); 2514 break; 2515 2516 case XenbusStateClosed: 2517 if (dev->state == XenbusStateClosed) 2518 break; 2519 fallthrough; /* Missed the backend's CLOSING state */ 2520 case XenbusStateClosing: 2521 xenbus_frontend_closed(dev); 2522 break; 2523 } 2524} 2525 2526static const struct xennet_stat { 2527 char name[ETH_GSTRING_LEN]; 2528 u16 offset; 2529} xennet_stats[] = { 2530 { 2531 "rx_gso_checksum_fixup", 2532 offsetof(struct netfront_info, rx_gso_checksum_fixup) 2533 }, 2534}; 2535 2536static int xennet_get_sset_count(struct net_device *dev, int string_set) 2537{ 2538 switch (string_set) { 2539 case ETH_SS_STATS: 2540 return ARRAY_SIZE(xennet_stats); 2541 default: 2542 return -EINVAL; 2543 } 2544} 2545 2546static void xennet_get_ethtool_stats(struct net_device *dev, 2547 struct ethtool_stats *stats, u64 * data) 2548{ 2549 void *np = netdev_priv(dev); 2550 int i; 2551 2552 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++) 2553 data[i] = atomic_read((atomic_t *)(np + xennet_stats[i].offset)); 2554} 2555 2556static void xennet_get_strings(struct net_device *dev, u32 stringset, u8 * data) 2557{ 2558 int i; 2559 2560 switch (stringset) { 2561 case ETH_SS_STATS: 2562 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++) 2563 memcpy(data + i * ETH_GSTRING_LEN, 2564 xennet_stats[i].name, ETH_GSTRING_LEN); 2565 break; 2566 } 2567} 2568 2569static const struct ethtool_ops xennet_ethtool_ops = 2570{ 2571 .get_link = ethtool_op_get_link, 2572 2573 .get_sset_count = xennet_get_sset_count, 2574 .get_ethtool_stats = xennet_get_ethtool_stats, 2575 .get_strings = xennet_get_strings, 2576 .get_ts_info = ethtool_op_get_ts_info, 2577}; 2578 2579#ifdef CONFIG_SYSFS 2580static ssize_t show_rxbuf(struct device *dev, 2581 struct device_attribute *attr, char *buf) 2582{ 2583 return sprintf(buf, "%lu\n", NET_RX_RING_SIZE); 2584} 2585 2586static ssize_t store_rxbuf(struct device *dev, 2587 struct device_attribute *attr, 2588 const char *buf, size_t len) 2589{ 2590 char *endp; 2591 2592 if (!capable(CAP_NET_ADMIN)) 2593 return -EPERM; 2594 2595 simple_strtoul(buf, &endp, 0); 2596 if (endp == buf) 2597 return -EBADMSG; 2598 2599 /* rxbuf_min and rxbuf_max are no longer configurable. */ 2600 2601 return len; 2602} 2603 2604static DEVICE_ATTR(rxbuf_min, 0644, show_rxbuf, store_rxbuf); 2605static DEVICE_ATTR(rxbuf_max, 0644, show_rxbuf, store_rxbuf); 2606static DEVICE_ATTR(rxbuf_cur, 0444, show_rxbuf, NULL); 2607 2608static struct attribute *xennet_dev_attrs[] = { 2609 &dev_attr_rxbuf_min.attr, 2610 &dev_attr_rxbuf_max.attr, 2611 &dev_attr_rxbuf_cur.attr, 2612 NULL 2613}; 2614 2615static const struct attribute_group xennet_dev_group = { 2616 .attrs = xennet_dev_attrs 2617}; 2618#endif /* CONFIG_SYSFS */ 2619 2620static void xennet_bus_close(struct xenbus_device *dev) 2621{ 2622 int ret; 2623 2624 if (xenbus_read_driver_state(dev->otherend) == XenbusStateClosed) 2625 return; 2626 do { 2627 xenbus_switch_state(dev, XenbusStateClosing); 2628 ret = wait_event_timeout(module_wq, 2629 xenbus_read_driver_state(dev->otherend) == 2630 XenbusStateClosing || 2631 xenbus_read_driver_state(dev->otherend) == 2632 XenbusStateClosed || 2633 xenbus_read_driver_state(dev->otherend) == 2634 XenbusStateUnknown, 2635 XENNET_TIMEOUT); 2636 } while (!ret); 2637 2638 if (xenbus_read_driver_state(dev->otherend) == XenbusStateClosed) 2639 return; 2640 2641 do { 2642 xenbus_switch_state(dev, XenbusStateClosed); 2643 ret = wait_event_timeout(module_wq, 2644 xenbus_read_driver_state(dev->otherend) == 2645 XenbusStateClosed || 2646 xenbus_read_driver_state(dev->otherend) == 2647 XenbusStateUnknown, 2648 XENNET_TIMEOUT); 2649 } while (!ret); 2650} 2651 2652static void xennet_remove(struct xenbus_device *dev) 2653{ 2654 struct netfront_info *info = dev_get_drvdata(&dev->dev); 2655 2656 xennet_bus_close(dev); 2657 xennet_disconnect_backend(info); 2658 2659 if (info->netdev->reg_state == NETREG_REGISTERED) 2660 unregister_netdev(info->netdev); 2661 2662 if (info->queues) { 2663 rtnl_lock(); 2664 xennet_destroy_queues(info); 2665 rtnl_unlock(); 2666 } 2667 xennet_free_netdev(info->netdev); 2668} 2669 2670static const struct xenbus_device_id netfront_ids[] = { 2671 { "vif" }, 2672 { "" } 2673}; 2674 2675static struct xenbus_driver netfront_driver = { 2676 .ids = netfront_ids, 2677 .probe = netfront_probe, 2678 .remove = xennet_remove, 2679 .resume = netfront_resume, 2680 .otherend_changed = netback_changed, 2681}; 2682 2683static int __init netif_init(void) 2684{ 2685 if (!xen_domain()) 2686 return -ENODEV; 2687 2688 if (!xen_has_pv_nic_devices()) 2689 return -ENODEV; 2690 2691 pr_info("Initialising Xen virtual ethernet driver\n"); 2692 2693 /* Allow as many queues as there are CPUs inut max. 8 if user has not 2694 * specified a value. 2695 */ 2696 if (xennet_max_queues == 0) 2697 xennet_max_queues = min_t(unsigned int, MAX_QUEUES_DEFAULT, 2698 num_online_cpus()); 2699 2700 return xenbus_register_frontend(&netfront_driver); 2701} 2702module_init(netif_init); 2703 2704 2705static void __exit netif_exit(void) 2706{ 2707 xenbus_unregister_driver(&netfront_driver); 2708} 2709module_exit(netif_exit); 2710 2711MODULE_DESCRIPTION("Xen virtual network device frontend"); 2712MODULE_LICENSE("GPL"); 2713MODULE_ALIAS("xen:vif"); 2714MODULE_ALIAS("xennet"); 2715