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 48 #include <xen/xen.h> 49 #include <xen/xenbus.h> 50 #include <xen/events.h> 51 #include <xen/page.h> 52 #include <xen/platform_pci.h> 53 #include <xen/grant_table.h> 54 55 #include <xen/interface/io/netif.h> 56 #include <xen/interface/memory.h> 57 #include <xen/interface/grant_table.h> 58 59 /* Module parameters */ 60 #define MAX_QUEUES_DEFAULT 8 61 static unsigned int xennet_max_queues; 62 module_param_named(max_queues, xennet_max_queues, uint, 0644); 63 MODULE_PARM_DESC(max_queues, 64 "Maximum number of queues per virtual interface"); 65 66 static const struct ethtool_ops xennet_ethtool_ops; 67 68 struct netfront_cb { 69 int pull_to; 70 }; 71 72 #define NETFRONT_SKB_CB(skb) ((struct netfront_cb *)((skb)->cb)) 73 74 #define RX_COPY_THRESHOLD 256 75 76 #define GRANT_INVALID_REF 0 77 78 #define NET_TX_RING_SIZE __CONST_RING_SIZE(xen_netif_tx, XEN_PAGE_SIZE) 79 #define NET_RX_RING_SIZE __CONST_RING_SIZE(xen_netif_rx, XEN_PAGE_SIZE) 80 81 /* Minimum number of Rx slots (includes slot for GSO metadata). */ 82 #define NET_RX_SLOTS_MIN (XEN_NETIF_NR_SLOTS_MIN + 1) 83 84 /* Queue name is interface name with "-qNNN" appended */ 85 #define QUEUE_NAME_SIZE (IFNAMSIZ + 6) 86 87 /* IRQ name is queue name with "-tx" or "-rx" appended */ 88 #define IRQ_NAME_SIZE (QUEUE_NAME_SIZE + 3) 89 90 static DECLARE_WAIT_QUEUE_HEAD(module_wq); 91 92 struct netfront_stats { 93 u64 packets; 94 u64 bytes; 95 struct u64_stats_sync syncp; 96 }; 97 98 struct netfront_info; 99 100 struct netfront_queue { 101 unsigned int id; /* Queue ID, 0-based */ 102 char name[QUEUE_NAME_SIZE]; /* DEVNAME-qN */ 103 struct netfront_info *info; 104 105 struct napi_struct napi; 106 107 /* Split event channels support, tx_* == rx_* when using 108 * single event channel. 109 */ 110 unsigned int tx_evtchn, rx_evtchn; 111 unsigned int tx_irq, rx_irq; 112 /* Only used when split event channels support is enabled */ 113 char tx_irq_name[IRQ_NAME_SIZE]; /* DEVNAME-qN-tx */ 114 char rx_irq_name[IRQ_NAME_SIZE]; /* DEVNAME-qN-rx */ 115 116 spinlock_t tx_lock; 117 struct xen_netif_tx_front_ring tx; 118 int tx_ring_ref; 119 120 /* 121 * {tx,rx}_skbs store outstanding skbuffs. Free tx_skb entries 122 * are linked from tx_skb_freelist through skb_entry.link. 123 * 124 * NB. Freelist index entries are always going to be less than 125 * PAGE_OFFSET, whereas pointers to skbs will always be equal or 126 * greater than PAGE_OFFSET: we use this property to distinguish 127 * them. 128 */ 129 union skb_entry { 130 struct sk_buff *skb; 131 unsigned long link; 132 } tx_skbs[NET_TX_RING_SIZE]; 133 grant_ref_t gref_tx_head; 134 grant_ref_t grant_tx_ref[NET_TX_RING_SIZE]; 135 struct page *grant_tx_page[NET_TX_RING_SIZE]; 136 unsigned tx_skb_freelist; 137 138 spinlock_t rx_lock ____cacheline_aligned_in_smp; 139 struct xen_netif_rx_front_ring rx; 140 int rx_ring_ref; 141 142 struct timer_list rx_refill_timer; 143 144 struct sk_buff *rx_skbs[NET_RX_RING_SIZE]; 145 grant_ref_t gref_rx_head; 146 grant_ref_t grant_rx_ref[NET_RX_RING_SIZE]; 147 }; 148 149 struct netfront_info { 150 struct list_head list; 151 struct net_device *netdev; 152 153 struct xenbus_device *xbdev; 154 155 /* Multi-queue support */ 156 struct netfront_queue *queues; 157 158 /* Statistics */ 159 struct netfront_stats __percpu *rx_stats; 160 struct netfront_stats __percpu *tx_stats; 161 162 atomic_t rx_gso_checksum_fixup; 163 }; 164 165 struct netfront_rx_info { 166 struct xen_netif_rx_response rx; 167 struct xen_netif_extra_info extras[XEN_NETIF_EXTRA_TYPE_MAX - 1]; 168 }; 169 170 static void skb_entry_set_link(union skb_entry *list, unsigned short id) 171 { 172 list->link = id; 173 } 174 175 static int skb_entry_is_link(const union skb_entry *list) 176 { 177 BUILD_BUG_ON(sizeof(list->skb) != sizeof(list->link)); 178 return (unsigned long)list->skb < PAGE_OFFSET; 179 } 180 181 /* 182 * Access macros for acquiring freeing slots in tx_skbs[]. 183 */ 184 185 static void add_id_to_freelist(unsigned *head, union skb_entry *list, 186 unsigned short id) 187 { 188 skb_entry_set_link(&list[id], *head); 189 *head = id; 190 } 191 192 static unsigned short get_id_from_freelist(unsigned *head, 193 union skb_entry *list) 194 { 195 unsigned int id = *head; 196 *head = list[id].link; 197 return id; 198 } 199 200 static int xennet_rxidx(RING_IDX idx) 201 { 202 return idx & (NET_RX_RING_SIZE - 1); 203 } 204 205 static struct sk_buff *xennet_get_rx_skb(struct netfront_queue *queue, 206 RING_IDX ri) 207 { 208 int i = xennet_rxidx(ri); 209 struct sk_buff *skb = queue->rx_skbs[i]; 210 queue->rx_skbs[i] = NULL; 211 return skb; 212 } 213 214 static grant_ref_t xennet_get_rx_ref(struct netfront_queue *queue, 215 RING_IDX ri) 216 { 217 int i = xennet_rxidx(ri); 218 grant_ref_t ref = queue->grant_rx_ref[i]; 219 queue->grant_rx_ref[i] = GRANT_INVALID_REF; 220 return ref; 221 } 222 223 #ifdef CONFIG_SYSFS 224 static const struct attribute_group xennet_dev_group; 225 #endif 226 227 static bool xennet_can_sg(struct net_device *dev) 228 { 229 return dev->features & NETIF_F_SG; 230 } 231 232 233 static void rx_refill_timeout(struct timer_list *t) 234 { 235 struct netfront_queue *queue = from_timer(queue, t, rx_refill_timer); 236 napi_schedule(&queue->napi); 237 } 238 239 static int netfront_tx_slot_available(struct netfront_queue *queue) 240 { 241 return (queue->tx.req_prod_pvt - queue->tx.rsp_cons) < 242 (NET_TX_RING_SIZE - XEN_NETIF_NR_SLOTS_MIN - 1); 243 } 244 245 static void xennet_maybe_wake_tx(struct netfront_queue *queue) 246 { 247 struct net_device *dev = queue->info->netdev; 248 struct netdev_queue *dev_queue = netdev_get_tx_queue(dev, queue->id); 249 250 if (unlikely(netif_tx_queue_stopped(dev_queue)) && 251 netfront_tx_slot_available(queue) && 252 likely(netif_running(dev))) 253 netif_tx_wake_queue(netdev_get_tx_queue(dev, queue->id)); 254 } 255 256 257 static struct sk_buff *xennet_alloc_one_rx_buffer(struct netfront_queue *queue) 258 { 259 struct sk_buff *skb; 260 struct page *page; 261 262 skb = __netdev_alloc_skb(queue->info->netdev, 263 RX_COPY_THRESHOLD + NET_IP_ALIGN, 264 GFP_ATOMIC | __GFP_NOWARN); 265 if (unlikely(!skb)) 266 return NULL; 267 268 page = alloc_page(GFP_ATOMIC | __GFP_NOWARN); 269 if (!page) { 270 kfree_skb(skb); 271 return NULL; 272 } 273 skb_add_rx_frag(skb, 0, page, 0, 0, PAGE_SIZE); 274 275 /* Align ip header to a 16 bytes boundary */ 276 skb_reserve(skb, NET_IP_ALIGN); 277 skb->dev = queue->info->netdev; 278 279 return skb; 280 } 281 282 283 static void xennet_alloc_rx_buffers(struct netfront_queue *queue) 284 { 285 RING_IDX req_prod = queue->rx.req_prod_pvt; 286 int notify; 287 int err = 0; 288 289 if (unlikely(!netif_carrier_ok(queue->info->netdev))) 290 return; 291 292 for (req_prod = queue->rx.req_prod_pvt; 293 req_prod - queue->rx.rsp_cons < NET_RX_RING_SIZE; 294 req_prod++) { 295 struct sk_buff *skb; 296 unsigned short id; 297 grant_ref_t ref; 298 struct page *page; 299 struct xen_netif_rx_request *req; 300 301 skb = xennet_alloc_one_rx_buffer(queue); 302 if (!skb) { 303 err = -ENOMEM; 304 break; 305 } 306 307 id = xennet_rxidx(req_prod); 308 309 BUG_ON(queue->rx_skbs[id]); 310 queue->rx_skbs[id] = skb; 311 312 ref = gnttab_claim_grant_reference(&queue->gref_rx_head); 313 WARN_ON_ONCE(IS_ERR_VALUE((unsigned long)(int)ref)); 314 queue->grant_rx_ref[id] = ref; 315 316 page = skb_frag_page(&skb_shinfo(skb)->frags[0]); 317 318 req = RING_GET_REQUEST(&queue->rx, req_prod); 319 gnttab_page_grant_foreign_access_ref_one(ref, 320 queue->info->xbdev->otherend_id, 321 page, 322 0); 323 req->id = id; 324 req->gref = ref; 325 } 326 327 queue->rx.req_prod_pvt = req_prod; 328 329 /* Try again later if there are not enough requests or skb allocation 330 * failed. 331 * Enough requests is quantified as the sum of newly created slots and 332 * the unconsumed slots at the backend. 333 */ 334 if (req_prod - queue->rx.rsp_cons < NET_RX_SLOTS_MIN || 335 unlikely(err)) { 336 mod_timer(&queue->rx_refill_timer, jiffies + (HZ/10)); 337 return; 338 } 339 340 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->rx, notify); 341 if (notify) 342 notify_remote_via_irq(queue->rx_irq); 343 } 344 345 static int xennet_open(struct net_device *dev) 346 { 347 struct netfront_info *np = netdev_priv(dev); 348 unsigned int num_queues = dev->real_num_tx_queues; 349 unsigned int i = 0; 350 struct netfront_queue *queue = NULL; 351 352 if (!np->queues) 353 return -ENODEV; 354 355 for (i = 0; i < num_queues; ++i) { 356 queue = &np->queues[i]; 357 napi_enable(&queue->napi); 358 359 spin_lock_bh(&queue->rx_lock); 360 if (netif_carrier_ok(dev)) { 361 xennet_alloc_rx_buffers(queue); 362 queue->rx.sring->rsp_event = queue->rx.rsp_cons + 1; 363 if (RING_HAS_UNCONSUMED_RESPONSES(&queue->rx)) 364 napi_schedule(&queue->napi); 365 } 366 spin_unlock_bh(&queue->rx_lock); 367 } 368 369 netif_tx_start_all_queues(dev); 370 371 return 0; 372 } 373 374 static void xennet_tx_buf_gc(struct netfront_queue *queue) 375 { 376 RING_IDX cons, prod; 377 unsigned short id; 378 struct sk_buff *skb; 379 bool more_to_do; 380 381 BUG_ON(!netif_carrier_ok(queue->info->netdev)); 382 383 do { 384 prod = queue->tx.sring->rsp_prod; 385 rmb(); /* Ensure we see responses up to 'rp'. */ 386 387 for (cons = queue->tx.rsp_cons; cons != prod; cons++) { 388 struct xen_netif_tx_response *txrsp; 389 390 txrsp = RING_GET_RESPONSE(&queue->tx, cons); 391 if (txrsp->status == XEN_NETIF_RSP_NULL) 392 continue; 393 394 id = txrsp->id; 395 skb = queue->tx_skbs[id].skb; 396 if (unlikely(gnttab_query_foreign_access( 397 queue->grant_tx_ref[id]) != 0)) { 398 pr_alert("%s: warning -- grant still in use by backend domain\n", 399 __func__); 400 BUG(); 401 } 402 gnttab_end_foreign_access_ref( 403 queue->grant_tx_ref[id], GNTMAP_readonly); 404 gnttab_release_grant_reference( 405 &queue->gref_tx_head, queue->grant_tx_ref[id]); 406 queue->grant_tx_ref[id] = GRANT_INVALID_REF; 407 queue->grant_tx_page[id] = NULL; 408 add_id_to_freelist(&queue->tx_skb_freelist, queue->tx_skbs, id); 409 dev_kfree_skb_irq(skb); 410 } 411 412 queue->tx.rsp_cons = prod; 413 414 RING_FINAL_CHECK_FOR_RESPONSES(&queue->tx, more_to_do); 415 } while (more_to_do); 416 417 xennet_maybe_wake_tx(queue); 418 } 419 420 struct xennet_gnttab_make_txreq { 421 struct netfront_queue *queue; 422 struct sk_buff *skb; 423 struct page *page; 424 struct xen_netif_tx_request *tx; /* Last request */ 425 unsigned int size; 426 }; 427 428 static void xennet_tx_setup_grant(unsigned long gfn, unsigned int offset, 429 unsigned int len, void *data) 430 { 431 struct xennet_gnttab_make_txreq *info = data; 432 unsigned int id; 433 struct xen_netif_tx_request *tx; 434 grant_ref_t ref; 435 /* convenient aliases */ 436 struct page *page = info->page; 437 struct netfront_queue *queue = info->queue; 438 struct sk_buff *skb = info->skb; 439 440 id = get_id_from_freelist(&queue->tx_skb_freelist, queue->tx_skbs); 441 tx = RING_GET_REQUEST(&queue->tx, queue->tx.req_prod_pvt++); 442 ref = gnttab_claim_grant_reference(&queue->gref_tx_head); 443 WARN_ON_ONCE(IS_ERR_VALUE((unsigned long)(int)ref)); 444 445 gnttab_grant_foreign_access_ref(ref, queue->info->xbdev->otherend_id, 446 gfn, GNTMAP_readonly); 447 448 queue->tx_skbs[id].skb = skb; 449 queue->grant_tx_page[id] = page; 450 queue->grant_tx_ref[id] = ref; 451 452 tx->id = id; 453 tx->gref = ref; 454 tx->offset = offset; 455 tx->size = len; 456 tx->flags = 0; 457 458 info->tx = tx; 459 info->size += tx->size; 460 } 461 462 static struct xen_netif_tx_request *xennet_make_first_txreq( 463 struct netfront_queue *queue, struct sk_buff *skb, 464 struct page *page, unsigned int offset, unsigned int len) 465 { 466 struct xennet_gnttab_make_txreq info = { 467 .queue = queue, 468 .skb = skb, 469 .page = page, 470 .size = 0, 471 }; 472 473 gnttab_for_one_grant(page, offset, len, xennet_tx_setup_grant, &info); 474 475 return info.tx; 476 } 477 478 static void xennet_make_one_txreq(unsigned long gfn, unsigned int offset, 479 unsigned int len, void *data) 480 { 481 struct xennet_gnttab_make_txreq *info = data; 482 483 info->tx->flags |= XEN_NETTXF_more_data; 484 skb_get(info->skb); 485 xennet_tx_setup_grant(gfn, offset, len, data); 486 } 487 488 static struct xen_netif_tx_request *xennet_make_txreqs( 489 struct netfront_queue *queue, struct xen_netif_tx_request *tx, 490 struct sk_buff *skb, struct page *page, 491 unsigned int offset, unsigned int len) 492 { 493 struct xennet_gnttab_make_txreq info = { 494 .queue = queue, 495 .skb = skb, 496 .tx = tx, 497 }; 498 499 /* Skip unused frames from start of page */ 500 page += offset >> PAGE_SHIFT; 501 offset &= ~PAGE_MASK; 502 503 while (len) { 504 info.page = page; 505 info.size = 0; 506 507 gnttab_foreach_grant_in_range(page, offset, len, 508 xennet_make_one_txreq, 509 &info); 510 511 page++; 512 offset = 0; 513 len -= info.size; 514 } 515 516 return info.tx; 517 } 518 519 /* 520 * Count how many ring slots are required to send this skb. Each frag 521 * might be a compound page. 522 */ 523 static int xennet_count_skb_slots(struct sk_buff *skb) 524 { 525 int i, frags = skb_shinfo(skb)->nr_frags; 526 int slots; 527 528 slots = gnttab_count_grant(offset_in_page(skb->data), 529 skb_headlen(skb)); 530 531 for (i = 0; i < frags; i++) { 532 skb_frag_t *frag = skb_shinfo(skb)->frags + i; 533 unsigned long size = skb_frag_size(frag); 534 unsigned long offset = frag->page_offset; 535 536 /* Skip unused frames from start of page */ 537 offset &= ~PAGE_MASK; 538 539 slots += gnttab_count_grant(offset, size); 540 } 541 542 return slots; 543 } 544 545 static u16 xennet_select_queue(struct net_device *dev, struct sk_buff *skb, 546 struct net_device *sb_dev) 547 { 548 unsigned int num_queues = dev->real_num_tx_queues; 549 u32 hash; 550 u16 queue_idx; 551 552 /* First, check if there is only one queue */ 553 if (num_queues == 1) { 554 queue_idx = 0; 555 } else { 556 hash = skb_get_hash(skb); 557 queue_idx = hash % num_queues; 558 } 559 560 return queue_idx; 561 } 562 563 #define MAX_XEN_SKB_FRAGS (65536 / XEN_PAGE_SIZE + 1) 564 565 static netdev_tx_t xennet_start_xmit(struct sk_buff *skb, struct net_device *dev) 566 { 567 struct netfront_info *np = netdev_priv(dev); 568 struct netfront_stats *tx_stats = this_cpu_ptr(np->tx_stats); 569 struct xen_netif_tx_request *tx, *first_tx; 570 unsigned int i; 571 int notify; 572 int slots; 573 struct page *page; 574 unsigned int offset; 575 unsigned int len; 576 unsigned long flags; 577 struct netfront_queue *queue = NULL; 578 unsigned int num_queues = dev->real_num_tx_queues; 579 u16 queue_index; 580 struct sk_buff *nskb; 581 582 /* Drop the packet if no queues are set up */ 583 if (num_queues < 1) 584 goto drop; 585 /* Determine which queue to transmit this SKB on */ 586 queue_index = skb_get_queue_mapping(skb); 587 queue = &np->queues[queue_index]; 588 589 /* If skb->len is too big for wire format, drop skb and alert 590 * user about misconfiguration. 591 */ 592 if (unlikely(skb->len > XEN_NETIF_MAX_TX_SIZE)) { 593 net_alert_ratelimited( 594 "xennet: skb->len = %u, too big for wire format\n", 595 skb->len); 596 goto drop; 597 } 598 599 slots = xennet_count_skb_slots(skb); 600 if (unlikely(slots > MAX_XEN_SKB_FRAGS + 1)) { 601 net_dbg_ratelimited("xennet: skb rides the rocket: %d slots, %d bytes\n", 602 slots, skb->len); 603 if (skb_linearize(skb)) 604 goto drop; 605 } 606 607 page = virt_to_page(skb->data); 608 offset = offset_in_page(skb->data); 609 610 /* The first req should be at least ETH_HLEN size or the packet will be 611 * dropped by netback. 612 */ 613 if (unlikely(PAGE_SIZE - offset < ETH_HLEN)) { 614 nskb = skb_copy(skb, GFP_ATOMIC); 615 if (!nskb) 616 goto drop; 617 dev_consume_skb_any(skb); 618 skb = nskb; 619 page = virt_to_page(skb->data); 620 offset = offset_in_page(skb->data); 621 } 622 623 len = skb_headlen(skb); 624 625 spin_lock_irqsave(&queue->tx_lock, flags); 626 627 if (unlikely(!netif_carrier_ok(dev) || 628 (slots > 1 && !xennet_can_sg(dev)) || 629 netif_needs_gso(skb, netif_skb_features(skb)))) { 630 spin_unlock_irqrestore(&queue->tx_lock, flags); 631 goto drop; 632 } 633 634 /* First request for the linear area. */ 635 first_tx = tx = xennet_make_first_txreq(queue, skb, 636 page, offset, len); 637 offset += tx->size; 638 if (offset == PAGE_SIZE) { 639 page++; 640 offset = 0; 641 } 642 len -= tx->size; 643 644 if (skb->ip_summed == CHECKSUM_PARTIAL) 645 /* local packet? */ 646 tx->flags |= XEN_NETTXF_csum_blank | XEN_NETTXF_data_validated; 647 else if (skb->ip_summed == CHECKSUM_UNNECESSARY) 648 /* remote but checksummed. */ 649 tx->flags |= XEN_NETTXF_data_validated; 650 651 /* Optional extra info after the first request. */ 652 if (skb_shinfo(skb)->gso_size) { 653 struct xen_netif_extra_info *gso; 654 655 gso = (struct xen_netif_extra_info *) 656 RING_GET_REQUEST(&queue->tx, queue->tx.req_prod_pvt++); 657 658 tx->flags |= XEN_NETTXF_extra_info; 659 660 gso->u.gso.size = skb_shinfo(skb)->gso_size; 661 gso->u.gso.type = (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6) ? 662 XEN_NETIF_GSO_TYPE_TCPV6 : 663 XEN_NETIF_GSO_TYPE_TCPV4; 664 gso->u.gso.pad = 0; 665 gso->u.gso.features = 0; 666 667 gso->type = XEN_NETIF_EXTRA_TYPE_GSO; 668 gso->flags = 0; 669 } 670 671 /* Requests for the rest of the linear area. */ 672 tx = xennet_make_txreqs(queue, tx, skb, page, offset, len); 673 674 /* Requests for all the frags. */ 675 for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { 676 skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; 677 tx = xennet_make_txreqs(queue, tx, skb, 678 skb_frag_page(frag), frag->page_offset, 679 skb_frag_size(frag)); 680 } 681 682 /* First request has the packet length. */ 683 first_tx->size = skb->len; 684 685 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->tx, notify); 686 if (notify) 687 notify_remote_via_irq(queue->tx_irq); 688 689 u64_stats_update_begin(&tx_stats->syncp); 690 tx_stats->bytes += skb->len; 691 tx_stats->packets++; 692 u64_stats_update_end(&tx_stats->syncp); 693 694 /* Note: It is not safe to access skb after xennet_tx_buf_gc()! */ 695 xennet_tx_buf_gc(queue); 696 697 if (!netfront_tx_slot_available(queue)) 698 netif_tx_stop_queue(netdev_get_tx_queue(dev, queue->id)); 699 700 spin_unlock_irqrestore(&queue->tx_lock, flags); 701 702 return NETDEV_TX_OK; 703 704 drop: 705 dev->stats.tx_dropped++; 706 dev_kfree_skb_any(skb); 707 return NETDEV_TX_OK; 708 } 709 710 static int xennet_close(struct net_device *dev) 711 { 712 struct netfront_info *np = netdev_priv(dev); 713 unsigned int num_queues = dev->real_num_tx_queues; 714 unsigned int i; 715 struct netfront_queue *queue; 716 netif_tx_stop_all_queues(np->netdev); 717 for (i = 0; i < num_queues; ++i) { 718 queue = &np->queues[i]; 719 napi_disable(&queue->napi); 720 } 721 return 0; 722 } 723 724 static void xennet_move_rx_slot(struct netfront_queue *queue, struct sk_buff *skb, 725 grant_ref_t ref) 726 { 727 int new = xennet_rxidx(queue->rx.req_prod_pvt); 728 729 BUG_ON(queue->rx_skbs[new]); 730 queue->rx_skbs[new] = skb; 731 queue->grant_rx_ref[new] = ref; 732 RING_GET_REQUEST(&queue->rx, queue->rx.req_prod_pvt)->id = new; 733 RING_GET_REQUEST(&queue->rx, queue->rx.req_prod_pvt)->gref = ref; 734 queue->rx.req_prod_pvt++; 735 } 736 737 static int xennet_get_extras(struct netfront_queue *queue, 738 struct xen_netif_extra_info *extras, 739 RING_IDX rp) 740 741 { 742 struct xen_netif_extra_info *extra; 743 struct device *dev = &queue->info->netdev->dev; 744 RING_IDX cons = queue->rx.rsp_cons; 745 int err = 0; 746 747 do { 748 struct sk_buff *skb; 749 grant_ref_t ref; 750 751 if (unlikely(cons + 1 == rp)) { 752 if (net_ratelimit()) 753 dev_warn(dev, "Missing extra info\n"); 754 err = -EBADR; 755 break; 756 } 757 758 extra = (struct xen_netif_extra_info *) 759 RING_GET_RESPONSE(&queue->rx, ++cons); 760 761 if (unlikely(!extra->type || 762 extra->type >= XEN_NETIF_EXTRA_TYPE_MAX)) { 763 if (net_ratelimit()) 764 dev_warn(dev, "Invalid extra type: %d\n", 765 extra->type); 766 err = -EINVAL; 767 } else { 768 memcpy(&extras[extra->type - 1], extra, 769 sizeof(*extra)); 770 } 771 772 skb = xennet_get_rx_skb(queue, cons); 773 ref = xennet_get_rx_ref(queue, cons); 774 xennet_move_rx_slot(queue, skb, ref); 775 } while (extra->flags & XEN_NETIF_EXTRA_FLAG_MORE); 776 777 queue->rx.rsp_cons = cons; 778 return err; 779 } 780 781 static int xennet_get_responses(struct netfront_queue *queue, 782 struct netfront_rx_info *rinfo, RING_IDX rp, 783 struct sk_buff_head *list) 784 { 785 struct xen_netif_rx_response *rx = &rinfo->rx; 786 struct xen_netif_extra_info *extras = rinfo->extras; 787 struct device *dev = &queue->info->netdev->dev; 788 RING_IDX cons = queue->rx.rsp_cons; 789 struct sk_buff *skb = xennet_get_rx_skb(queue, cons); 790 grant_ref_t ref = xennet_get_rx_ref(queue, cons); 791 int max = XEN_NETIF_NR_SLOTS_MIN + (rx->status <= RX_COPY_THRESHOLD); 792 int slots = 1; 793 int err = 0; 794 unsigned long ret; 795 796 if (rx->flags & XEN_NETRXF_extra_info) { 797 err = xennet_get_extras(queue, extras, rp); 798 cons = queue->rx.rsp_cons; 799 } 800 801 for (;;) { 802 if (unlikely(rx->status < 0 || 803 rx->offset + rx->status > XEN_PAGE_SIZE)) { 804 if (net_ratelimit()) 805 dev_warn(dev, "rx->offset: %u, size: %d\n", 806 rx->offset, rx->status); 807 xennet_move_rx_slot(queue, skb, ref); 808 err = -EINVAL; 809 goto next; 810 } 811 812 /* 813 * This definitely indicates a bug, either in this driver or in 814 * the backend driver. In future this should flag the bad 815 * situation to the system controller to reboot the backend. 816 */ 817 if (ref == GRANT_INVALID_REF) { 818 if (net_ratelimit()) 819 dev_warn(dev, "Bad rx response id %d.\n", 820 rx->id); 821 err = -EINVAL; 822 goto next; 823 } 824 825 ret = gnttab_end_foreign_access_ref(ref, 0); 826 BUG_ON(!ret); 827 828 gnttab_release_grant_reference(&queue->gref_rx_head, ref); 829 830 __skb_queue_tail(list, skb); 831 832 next: 833 if (!(rx->flags & XEN_NETRXF_more_data)) 834 break; 835 836 if (cons + slots == rp) { 837 if (net_ratelimit()) 838 dev_warn(dev, "Need more slots\n"); 839 err = -ENOENT; 840 break; 841 } 842 843 rx = RING_GET_RESPONSE(&queue->rx, cons + slots); 844 skb = xennet_get_rx_skb(queue, cons + slots); 845 ref = xennet_get_rx_ref(queue, cons + slots); 846 slots++; 847 } 848 849 if (unlikely(slots > max)) { 850 if (net_ratelimit()) 851 dev_warn(dev, "Too many slots\n"); 852 err = -E2BIG; 853 } 854 855 if (unlikely(err)) 856 queue->rx.rsp_cons = cons + slots; 857 858 return err; 859 } 860 861 static int xennet_set_skb_gso(struct sk_buff *skb, 862 struct xen_netif_extra_info *gso) 863 { 864 if (!gso->u.gso.size) { 865 if (net_ratelimit()) 866 pr_warn("GSO size must not be zero\n"); 867 return -EINVAL; 868 } 869 870 if (gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV4 && 871 gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV6) { 872 if (net_ratelimit()) 873 pr_warn("Bad GSO type %d\n", gso->u.gso.type); 874 return -EINVAL; 875 } 876 877 skb_shinfo(skb)->gso_size = gso->u.gso.size; 878 skb_shinfo(skb)->gso_type = 879 (gso->u.gso.type == XEN_NETIF_GSO_TYPE_TCPV4) ? 880 SKB_GSO_TCPV4 : 881 SKB_GSO_TCPV6; 882 883 /* Header must be checked, and gso_segs computed. */ 884 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY; 885 skb_shinfo(skb)->gso_segs = 0; 886 887 return 0; 888 } 889 890 static RING_IDX xennet_fill_frags(struct netfront_queue *queue, 891 struct sk_buff *skb, 892 struct sk_buff_head *list) 893 { 894 RING_IDX cons = queue->rx.rsp_cons; 895 struct sk_buff *nskb; 896 897 while ((nskb = __skb_dequeue(list))) { 898 struct xen_netif_rx_response *rx = 899 RING_GET_RESPONSE(&queue->rx, ++cons); 900 skb_frag_t *nfrag = &skb_shinfo(nskb)->frags[0]; 901 902 if (skb_shinfo(skb)->nr_frags == MAX_SKB_FRAGS) { 903 unsigned int pull_to = NETFRONT_SKB_CB(skb)->pull_to; 904 905 BUG_ON(pull_to < skb_headlen(skb)); 906 __pskb_pull_tail(skb, pull_to - skb_headlen(skb)); 907 } 908 if (unlikely(skb_shinfo(skb)->nr_frags >= MAX_SKB_FRAGS)) { 909 queue->rx.rsp_cons = ++cons; 910 kfree_skb(nskb); 911 return ~0U; 912 } 913 914 skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, 915 skb_frag_page(nfrag), 916 rx->offset, rx->status, PAGE_SIZE); 917 918 skb_shinfo(nskb)->nr_frags = 0; 919 kfree_skb(nskb); 920 } 921 922 return cons; 923 } 924 925 static int checksum_setup(struct net_device *dev, struct sk_buff *skb) 926 { 927 bool recalculate_partial_csum = false; 928 929 /* 930 * A GSO SKB must be CHECKSUM_PARTIAL. However some buggy 931 * peers can fail to set NETRXF_csum_blank when sending a GSO 932 * frame. In this case force the SKB to CHECKSUM_PARTIAL and 933 * recalculate the partial checksum. 934 */ 935 if (skb->ip_summed != CHECKSUM_PARTIAL && skb_is_gso(skb)) { 936 struct netfront_info *np = netdev_priv(dev); 937 atomic_inc(&np->rx_gso_checksum_fixup); 938 skb->ip_summed = CHECKSUM_PARTIAL; 939 recalculate_partial_csum = true; 940 } 941 942 /* A non-CHECKSUM_PARTIAL SKB does not require setup. */ 943 if (skb->ip_summed != CHECKSUM_PARTIAL) 944 return 0; 945 946 return skb_checksum_setup(skb, recalculate_partial_csum); 947 } 948 949 static int handle_incoming_queue(struct netfront_queue *queue, 950 struct sk_buff_head *rxq) 951 { 952 struct netfront_stats *rx_stats = this_cpu_ptr(queue->info->rx_stats); 953 int packets_dropped = 0; 954 struct sk_buff *skb; 955 956 while ((skb = __skb_dequeue(rxq)) != NULL) { 957 int pull_to = NETFRONT_SKB_CB(skb)->pull_to; 958 959 if (pull_to > skb_headlen(skb)) 960 __pskb_pull_tail(skb, pull_to - skb_headlen(skb)); 961 962 /* Ethernet work: Delayed to here as it peeks the header. */ 963 skb->protocol = eth_type_trans(skb, queue->info->netdev); 964 skb_reset_network_header(skb); 965 966 if (checksum_setup(queue->info->netdev, skb)) { 967 kfree_skb(skb); 968 packets_dropped++; 969 queue->info->netdev->stats.rx_errors++; 970 continue; 971 } 972 973 u64_stats_update_begin(&rx_stats->syncp); 974 rx_stats->packets++; 975 rx_stats->bytes += skb->len; 976 u64_stats_update_end(&rx_stats->syncp); 977 978 /* Pass it up. */ 979 napi_gro_receive(&queue->napi, skb); 980 } 981 982 return packets_dropped; 983 } 984 985 static int xennet_poll(struct napi_struct *napi, int budget) 986 { 987 struct netfront_queue *queue = container_of(napi, struct netfront_queue, napi); 988 struct net_device *dev = queue->info->netdev; 989 struct sk_buff *skb; 990 struct netfront_rx_info rinfo; 991 struct xen_netif_rx_response *rx = &rinfo.rx; 992 struct xen_netif_extra_info *extras = rinfo.extras; 993 RING_IDX i, rp; 994 int work_done; 995 struct sk_buff_head rxq; 996 struct sk_buff_head errq; 997 struct sk_buff_head tmpq; 998 int err; 999 1000 spin_lock(&queue->rx_lock); 1001 1002 skb_queue_head_init(&rxq); 1003 skb_queue_head_init(&errq); 1004 skb_queue_head_init(&tmpq); 1005 1006 rp = queue->rx.sring->rsp_prod; 1007 rmb(); /* Ensure we see queued responses up to 'rp'. */ 1008 1009 i = queue->rx.rsp_cons; 1010 work_done = 0; 1011 while ((i != rp) && (work_done < budget)) { 1012 memcpy(rx, RING_GET_RESPONSE(&queue->rx, i), sizeof(*rx)); 1013 memset(extras, 0, sizeof(rinfo.extras)); 1014 1015 err = xennet_get_responses(queue, &rinfo, rp, &tmpq); 1016 1017 if (unlikely(err)) { 1018 err: 1019 while ((skb = __skb_dequeue(&tmpq))) 1020 __skb_queue_tail(&errq, skb); 1021 dev->stats.rx_errors++; 1022 i = queue->rx.rsp_cons; 1023 continue; 1024 } 1025 1026 skb = __skb_dequeue(&tmpq); 1027 1028 if (extras[XEN_NETIF_EXTRA_TYPE_GSO - 1].type) { 1029 struct xen_netif_extra_info *gso; 1030 gso = &extras[XEN_NETIF_EXTRA_TYPE_GSO - 1]; 1031 1032 if (unlikely(xennet_set_skb_gso(skb, gso))) { 1033 __skb_queue_head(&tmpq, skb); 1034 queue->rx.rsp_cons += skb_queue_len(&tmpq); 1035 goto err; 1036 } 1037 } 1038 1039 NETFRONT_SKB_CB(skb)->pull_to = rx->status; 1040 if (NETFRONT_SKB_CB(skb)->pull_to > RX_COPY_THRESHOLD) 1041 NETFRONT_SKB_CB(skb)->pull_to = RX_COPY_THRESHOLD; 1042 1043 skb_shinfo(skb)->frags[0].page_offset = rx->offset; 1044 skb_frag_size_set(&skb_shinfo(skb)->frags[0], rx->status); 1045 skb->data_len = rx->status; 1046 skb->len += rx->status; 1047 1048 i = xennet_fill_frags(queue, skb, &tmpq); 1049 if (unlikely(i == ~0U)) 1050 goto err; 1051 1052 if (rx->flags & XEN_NETRXF_csum_blank) 1053 skb->ip_summed = CHECKSUM_PARTIAL; 1054 else if (rx->flags & XEN_NETRXF_data_validated) 1055 skb->ip_summed = CHECKSUM_UNNECESSARY; 1056 1057 __skb_queue_tail(&rxq, skb); 1058 1059 queue->rx.rsp_cons = ++i; 1060 work_done++; 1061 } 1062 1063 __skb_queue_purge(&errq); 1064 1065 work_done -= handle_incoming_queue(queue, &rxq); 1066 1067 xennet_alloc_rx_buffers(queue); 1068 1069 if (work_done < budget) { 1070 int more_to_do = 0; 1071 1072 napi_complete_done(napi, work_done); 1073 1074 RING_FINAL_CHECK_FOR_RESPONSES(&queue->rx, more_to_do); 1075 if (more_to_do) 1076 napi_schedule(napi); 1077 } 1078 1079 spin_unlock(&queue->rx_lock); 1080 1081 return work_done; 1082 } 1083 1084 static int xennet_change_mtu(struct net_device *dev, int mtu) 1085 { 1086 int max = xennet_can_sg(dev) ? XEN_NETIF_MAX_TX_SIZE : ETH_DATA_LEN; 1087 1088 if (mtu > max) 1089 return -EINVAL; 1090 dev->mtu = mtu; 1091 return 0; 1092 } 1093 1094 static void xennet_get_stats64(struct net_device *dev, 1095 struct rtnl_link_stats64 *tot) 1096 { 1097 struct netfront_info *np = netdev_priv(dev); 1098 int cpu; 1099 1100 for_each_possible_cpu(cpu) { 1101 struct netfront_stats *rx_stats = per_cpu_ptr(np->rx_stats, cpu); 1102 struct netfront_stats *tx_stats = per_cpu_ptr(np->tx_stats, cpu); 1103 u64 rx_packets, rx_bytes, tx_packets, tx_bytes; 1104 unsigned int start; 1105 1106 do { 1107 start = u64_stats_fetch_begin_irq(&tx_stats->syncp); 1108 tx_packets = tx_stats->packets; 1109 tx_bytes = tx_stats->bytes; 1110 } while (u64_stats_fetch_retry_irq(&tx_stats->syncp, start)); 1111 1112 do { 1113 start = u64_stats_fetch_begin_irq(&rx_stats->syncp); 1114 rx_packets = rx_stats->packets; 1115 rx_bytes = rx_stats->bytes; 1116 } while (u64_stats_fetch_retry_irq(&rx_stats->syncp, start)); 1117 1118 tot->rx_packets += rx_packets; 1119 tot->tx_packets += tx_packets; 1120 tot->rx_bytes += rx_bytes; 1121 tot->tx_bytes += tx_bytes; 1122 } 1123 1124 tot->rx_errors = dev->stats.rx_errors; 1125 tot->tx_dropped = dev->stats.tx_dropped; 1126 } 1127 1128 static void xennet_release_tx_bufs(struct netfront_queue *queue) 1129 { 1130 struct sk_buff *skb; 1131 int i; 1132 1133 for (i = 0; i < NET_TX_RING_SIZE; i++) { 1134 /* Skip over entries which are actually freelist references */ 1135 if (skb_entry_is_link(&queue->tx_skbs[i])) 1136 continue; 1137 1138 skb = queue->tx_skbs[i].skb; 1139 get_page(queue->grant_tx_page[i]); 1140 gnttab_end_foreign_access(queue->grant_tx_ref[i], 1141 GNTMAP_readonly, 1142 (unsigned long)page_address(queue->grant_tx_page[i])); 1143 queue->grant_tx_page[i] = NULL; 1144 queue->grant_tx_ref[i] = GRANT_INVALID_REF; 1145 add_id_to_freelist(&queue->tx_skb_freelist, queue->tx_skbs, i); 1146 dev_kfree_skb_irq(skb); 1147 } 1148 } 1149 1150 static void xennet_release_rx_bufs(struct netfront_queue *queue) 1151 { 1152 int id, ref; 1153 1154 spin_lock_bh(&queue->rx_lock); 1155 1156 for (id = 0; id < NET_RX_RING_SIZE; id++) { 1157 struct sk_buff *skb; 1158 struct page *page; 1159 1160 skb = queue->rx_skbs[id]; 1161 if (!skb) 1162 continue; 1163 1164 ref = queue->grant_rx_ref[id]; 1165 if (ref == GRANT_INVALID_REF) 1166 continue; 1167 1168 page = skb_frag_page(&skb_shinfo(skb)->frags[0]); 1169 1170 /* gnttab_end_foreign_access() needs a page ref until 1171 * foreign access is ended (which may be deferred). 1172 */ 1173 get_page(page); 1174 gnttab_end_foreign_access(ref, 0, 1175 (unsigned long)page_address(page)); 1176 queue->grant_rx_ref[id] = GRANT_INVALID_REF; 1177 1178 kfree_skb(skb); 1179 } 1180 1181 spin_unlock_bh(&queue->rx_lock); 1182 } 1183 1184 static netdev_features_t xennet_fix_features(struct net_device *dev, 1185 netdev_features_t features) 1186 { 1187 struct netfront_info *np = netdev_priv(dev); 1188 1189 if (features & NETIF_F_SG && 1190 !xenbus_read_unsigned(np->xbdev->otherend, "feature-sg", 0)) 1191 features &= ~NETIF_F_SG; 1192 1193 if (features & NETIF_F_IPV6_CSUM && 1194 !xenbus_read_unsigned(np->xbdev->otherend, 1195 "feature-ipv6-csum-offload", 0)) 1196 features &= ~NETIF_F_IPV6_CSUM; 1197 1198 if (features & NETIF_F_TSO && 1199 !xenbus_read_unsigned(np->xbdev->otherend, "feature-gso-tcpv4", 0)) 1200 features &= ~NETIF_F_TSO; 1201 1202 if (features & NETIF_F_TSO6 && 1203 !xenbus_read_unsigned(np->xbdev->otherend, "feature-gso-tcpv6", 0)) 1204 features &= ~NETIF_F_TSO6; 1205 1206 return features; 1207 } 1208 1209 static int xennet_set_features(struct net_device *dev, 1210 netdev_features_t features) 1211 { 1212 if (!(features & NETIF_F_SG) && dev->mtu > ETH_DATA_LEN) { 1213 netdev_info(dev, "Reducing MTU because no SG offload"); 1214 dev->mtu = ETH_DATA_LEN; 1215 } 1216 1217 return 0; 1218 } 1219 1220 static irqreturn_t xennet_tx_interrupt(int irq, void *dev_id) 1221 { 1222 struct netfront_queue *queue = dev_id; 1223 unsigned long flags; 1224 1225 spin_lock_irqsave(&queue->tx_lock, flags); 1226 xennet_tx_buf_gc(queue); 1227 spin_unlock_irqrestore(&queue->tx_lock, flags); 1228 1229 return IRQ_HANDLED; 1230 } 1231 1232 static irqreturn_t xennet_rx_interrupt(int irq, void *dev_id) 1233 { 1234 struct netfront_queue *queue = dev_id; 1235 struct net_device *dev = queue->info->netdev; 1236 1237 if (likely(netif_carrier_ok(dev) && 1238 RING_HAS_UNCONSUMED_RESPONSES(&queue->rx))) 1239 napi_schedule(&queue->napi); 1240 1241 return IRQ_HANDLED; 1242 } 1243 1244 static irqreturn_t xennet_interrupt(int irq, void *dev_id) 1245 { 1246 xennet_tx_interrupt(irq, dev_id); 1247 xennet_rx_interrupt(irq, dev_id); 1248 return IRQ_HANDLED; 1249 } 1250 1251 #ifdef CONFIG_NET_POLL_CONTROLLER 1252 static void xennet_poll_controller(struct net_device *dev) 1253 { 1254 /* Poll each queue */ 1255 struct netfront_info *info = netdev_priv(dev); 1256 unsigned int num_queues = dev->real_num_tx_queues; 1257 unsigned int i; 1258 for (i = 0; i < num_queues; ++i) 1259 xennet_interrupt(0, &info->queues[i]); 1260 } 1261 #endif 1262 1263 static const struct net_device_ops xennet_netdev_ops = { 1264 .ndo_open = xennet_open, 1265 .ndo_stop = xennet_close, 1266 .ndo_start_xmit = xennet_start_xmit, 1267 .ndo_change_mtu = xennet_change_mtu, 1268 .ndo_get_stats64 = xennet_get_stats64, 1269 .ndo_set_mac_address = eth_mac_addr, 1270 .ndo_validate_addr = eth_validate_addr, 1271 .ndo_fix_features = xennet_fix_features, 1272 .ndo_set_features = xennet_set_features, 1273 .ndo_select_queue = xennet_select_queue, 1274 #ifdef CONFIG_NET_POLL_CONTROLLER 1275 .ndo_poll_controller = xennet_poll_controller, 1276 #endif 1277 }; 1278 1279 static void xennet_free_netdev(struct net_device *netdev) 1280 { 1281 struct netfront_info *np = netdev_priv(netdev); 1282 1283 free_percpu(np->rx_stats); 1284 free_percpu(np->tx_stats); 1285 free_netdev(netdev); 1286 } 1287 1288 static struct net_device *xennet_create_dev(struct xenbus_device *dev) 1289 { 1290 int err; 1291 struct net_device *netdev; 1292 struct netfront_info *np; 1293 1294 netdev = alloc_etherdev_mq(sizeof(struct netfront_info), xennet_max_queues); 1295 if (!netdev) 1296 return ERR_PTR(-ENOMEM); 1297 1298 np = netdev_priv(netdev); 1299 np->xbdev = dev; 1300 1301 np->queues = NULL; 1302 1303 err = -ENOMEM; 1304 np->rx_stats = netdev_alloc_pcpu_stats(struct netfront_stats); 1305 if (np->rx_stats == NULL) 1306 goto exit; 1307 np->tx_stats = netdev_alloc_pcpu_stats(struct netfront_stats); 1308 if (np->tx_stats == NULL) 1309 goto exit; 1310 1311 netdev->netdev_ops = &xennet_netdev_ops; 1312 1313 netdev->features = NETIF_F_IP_CSUM | NETIF_F_RXCSUM | 1314 NETIF_F_GSO_ROBUST; 1315 netdev->hw_features = NETIF_F_SG | 1316 NETIF_F_IPV6_CSUM | 1317 NETIF_F_TSO | NETIF_F_TSO6; 1318 1319 /* 1320 * Assume that all hw features are available for now. This set 1321 * will be adjusted by the call to netdev_update_features() in 1322 * xennet_connect() which is the earliest point where we can 1323 * negotiate with the backend regarding supported features. 1324 */ 1325 netdev->features |= netdev->hw_features; 1326 1327 netdev->ethtool_ops = &xennet_ethtool_ops; 1328 netdev->min_mtu = ETH_MIN_MTU; 1329 netdev->max_mtu = XEN_NETIF_MAX_TX_SIZE; 1330 SET_NETDEV_DEV(netdev, &dev->dev); 1331 1332 np->netdev = netdev; 1333 1334 netif_carrier_off(netdev); 1335 1336 xenbus_switch_state(dev, XenbusStateInitialising); 1337 wait_event(module_wq, 1338 xenbus_read_driver_state(dev->otherend) != 1339 XenbusStateClosed && 1340 xenbus_read_driver_state(dev->otherend) != 1341 XenbusStateUnknown); 1342 return netdev; 1343 1344 exit: 1345 xennet_free_netdev(netdev); 1346 return ERR_PTR(err); 1347 } 1348 1349 /** 1350 * Entry point to this code when a new device is created. Allocate the basic 1351 * structures and the ring buffers for communication with the backend, and 1352 * inform the backend of the appropriate details for those. 1353 */ 1354 static int netfront_probe(struct xenbus_device *dev, 1355 const struct xenbus_device_id *id) 1356 { 1357 int err; 1358 struct net_device *netdev; 1359 struct netfront_info *info; 1360 1361 netdev = xennet_create_dev(dev); 1362 if (IS_ERR(netdev)) { 1363 err = PTR_ERR(netdev); 1364 xenbus_dev_fatal(dev, err, "creating netdev"); 1365 return err; 1366 } 1367 1368 info = netdev_priv(netdev); 1369 dev_set_drvdata(&dev->dev, info); 1370 #ifdef CONFIG_SYSFS 1371 info->netdev->sysfs_groups[0] = &xennet_dev_group; 1372 #endif 1373 1374 return 0; 1375 } 1376 1377 static void xennet_end_access(int ref, void *page) 1378 { 1379 /* This frees the page as a side-effect */ 1380 if (ref != GRANT_INVALID_REF) 1381 gnttab_end_foreign_access(ref, 0, (unsigned long)page); 1382 } 1383 1384 static void xennet_disconnect_backend(struct netfront_info *info) 1385 { 1386 unsigned int i = 0; 1387 unsigned int num_queues = info->netdev->real_num_tx_queues; 1388 1389 netif_carrier_off(info->netdev); 1390 1391 for (i = 0; i < num_queues && info->queues; ++i) { 1392 struct netfront_queue *queue = &info->queues[i]; 1393 1394 del_timer_sync(&queue->rx_refill_timer); 1395 1396 if (queue->tx_irq && (queue->tx_irq == queue->rx_irq)) 1397 unbind_from_irqhandler(queue->tx_irq, queue); 1398 if (queue->tx_irq && (queue->tx_irq != queue->rx_irq)) { 1399 unbind_from_irqhandler(queue->tx_irq, queue); 1400 unbind_from_irqhandler(queue->rx_irq, queue); 1401 } 1402 queue->tx_evtchn = queue->rx_evtchn = 0; 1403 queue->tx_irq = queue->rx_irq = 0; 1404 1405 if (netif_running(info->netdev)) 1406 napi_synchronize(&queue->napi); 1407 1408 xennet_release_tx_bufs(queue); 1409 xennet_release_rx_bufs(queue); 1410 gnttab_free_grant_references(queue->gref_tx_head); 1411 gnttab_free_grant_references(queue->gref_rx_head); 1412 1413 /* End access and free the pages */ 1414 xennet_end_access(queue->tx_ring_ref, queue->tx.sring); 1415 xennet_end_access(queue->rx_ring_ref, queue->rx.sring); 1416 1417 queue->tx_ring_ref = GRANT_INVALID_REF; 1418 queue->rx_ring_ref = GRANT_INVALID_REF; 1419 queue->tx.sring = NULL; 1420 queue->rx.sring = NULL; 1421 } 1422 } 1423 1424 /** 1425 * We are reconnecting to the backend, due to a suspend/resume, or a backend 1426 * driver restart. We tear down our netif structure and recreate it, but 1427 * leave the device-layer structures intact so that this is transparent to the 1428 * rest of the kernel. 1429 */ 1430 static int netfront_resume(struct xenbus_device *dev) 1431 { 1432 struct netfront_info *info = dev_get_drvdata(&dev->dev); 1433 1434 dev_dbg(&dev->dev, "%s\n", dev->nodename); 1435 1436 xennet_disconnect_backend(info); 1437 return 0; 1438 } 1439 1440 static int xen_net_read_mac(struct xenbus_device *dev, u8 mac[]) 1441 { 1442 char *s, *e, *macstr; 1443 int i; 1444 1445 macstr = s = xenbus_read(XBT_NIL, dev->nodename, "mac", NULL); 1446 if (IS_ERR(macstr)) 1447 return PTR_ERR(macstr); 1448 1449 for (i = 0; i < ETH_ALEN; i++) { 1450 mac[i] = simple_strtoul(s, &e, 16); 1451 if ((s == e) || (*e != ((i == ETH_ALEN-1) ? '\0' : ':'))) { 1452 kfree(macstr); 1453 return -ENOENT; 1454 } 1455 s = e+1; 1456 } 1457 1458 kfree(macstr); 1459 return 0; 1460 } 1461 1462 static int setup_netfront_single(struct netfront_queue *queue) 1463 { 1464 int err; 1465 1466 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->tx_evtchn); 1467 if (err < 0) 1468 goto fail; 1469 1470 err = bind_evtchn_to_irqhandler(queue->tx_evtchn, 1471 xennet_interrupt, 1472 0, queue->info->netdev->name, queue); 1473 if (err < 0) 1474 goto bind_fail; 1475 queue->rx_evtchn = queue->tx_evtchn; 1476 queue->rx_irq = queue->tx_irq = err; 1477 1478 return 0; 1479 1480 bind_fail: 1481 xenbus_free_evtchn(queue->info->xbdev, queue->tx_evtchn); 1482 queue->tx_evtchn = 0; 1483 fail: 1484 return err; 1485 } 1486 1487 static int setup_netfront_split(struct netfront_queue *queue) 1488 { 1489 int err; 1490 1491 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->tx_evtchn); 1492 if (err < 0) 1493 goto fail; 1494 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->rx_evtchn); 1495 if (err < 0) 1496 goto alloc_rx_evtchn_fail; 1497 1498 snprintf(queue->tx_irq_name, sizeof(queue->tx_irq_name), 1499 "%s-tx", queue->name); 1500 err = bind_evtchn_to_irqhandler(queue->tx_evtchn, 1501 xennet_tx_interrupt, 1502 0, queue->tx_irq_name, queue); 1503 if (err < 0) 1504 goto bind_tx_fail; 1505 queue->tx_irq = err; 1506 1507 snprintf(queue->rx_irq_name, sizeof(queue->rx_irq_name), 1508 "%s-rx", queue->name); 1509 err = bind_evtchn_to_irqhandler(queue->rx_evtchn, 1510 xennet_rx_interrupt, 1511 0, queue->rx_irq_name, queue); 1512 if (err < 0) 1513 goto bind_rx_fail; 1514 queue->rx_irq = err; 1515 1516 return 0; 1517 1518 bind_rx_fail: 1519 unbind_from_irqhandler(queue->tx_irq, queue); 1520 queue->tx_irq = 0; 1521 bind_tx_fail: 1522 xenbus_free_evtchn(queue->info->xbdev, queue->rx_evtchn); 1523 queue->rx_evtchn = 0; 1524 alloc_rx_evtchn_fail: 1525 xenbus_free_evtchn(queue->info->xbdev, queue->tx_evtchn); 1526 queue->tx_evtchn = 0; 1527 fail: 1528 return err; 1529 } 1530 1531 static int setup_netfront(struct xenbus_device *dev, 1532 struct netfront_queue *queue, unsigned int feature_split_evtchn) 1533 { 1534 struct xen_netif_tx_sring *txs; 1535 struct xen_netif_rx_sring *rxs; 1536 grant_ref_t gref; 1537 int err; 1538 1539 queue->tx_ring_ref = GRANT_INVALID_REF; 1540 queue->rx_ring_ref = GRANT_INVALID_REF; 1541 queue->rx.sring = NULL; 1542 queue->tx.sring = NULL; 1543 1544 txs = (struct xen_netif_tx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH); 1545 if (!txs) { 1546 err = -ENOMEM; 1547 xenbus_dev_fatal(dev, err, "allocating tx ring page"); 1548 goto fail; 1549 } 1550 SHARED_RING_INIT(txs); 1551 FRONT_RING_INIT(&queue->tx, txs, XEN_PAGE_SIZE); 1552 1553 err = xenbus_grant_ring(dev, txs, 1, &gref); 1554 if (err < 0) 1555 goto grant_tx_ring_fail; 1556 queue->tx_ring_ref = gref; 1557 1558 rxs = (struct xen_netif_rx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH); 1559 if (!rxs) { 1560 err = -ENOMEM; 1561 xenbus_dev_fatal(dev, err, "allocating rx ring page"); 1562 goto alloc_rx_ring_fail; 1563 } 1564 SHARED_RING_INIT(rxs); 1565 FRONT_RING_INIT(&queue->rx, rxs, XEN_PAGE_SIZE); 1566 1567 err = xenbus_grant_ring(dev, rxs, 1, &gref); 1568 if (err < 0) 1569 goto grant_rx_ring_fail; 1570 queue->rx_ring_ref = gref; 1571 1572 if (feature_split_evtchn) 1573 err = setup_netfront_split(queue); 1574 /* setup single event channel if 1575 * a) feature-split-event-channels == 0 1576 * b) feature-split-event-channels == 1 but failed to setup 1577 */ 1578 if (!feature_split_evtchn || (feature_split_evtchn && err)) 1579 err = setup_netfront_single(queue); 1580 1581 if (err) 1582 goto alloc_evtchn_fail; 1583 1584 return 0; 1585 1586 /* If we fail to setup netfront, it is safe to just revoke access to 1587 * granted pages because backend is not accessing it at this point. 1588 */ 1589 alloc_evtchn_fail: 1590 gnttab_end_foreign_access_ref(queue->rx_ring_ref, 0); 1591 grant_rx_ring_fail: 1592 free_page((unsigned long)rxs); 1593 alloc_rx_ring_fail: 1594 gnttab_end_foreign_access_ref(queue->tx_ring_ref, 0); 1595 grant_tx_ring_fail: 1596 free_page((unsigned long)txs); 1597 fail: 1598 return err; 1599 } 1600 1601 /* Queue-specific initialisation 1602 * This used to be done in xennet_create_dev() but must now 1603 * be run per-queue. 1604 */ 1605 static int xennet_init_queue(struct netfront_queue *queue) 1606 { 1607 unsigned short i; 1608 int err = 0; 1609 char *devid; 1610 1611 spin_lock_init(&queue->tx_lock); 1612 spin_lock_init(&queue->rx_lock); 1613 1614 timer_setup(&queue->rx_refill_timer, rx_refill_timeout, 0); 1615 1616 devid = strrchr(queue->info->xbdev->nodename, '/') + 1; 1617 snprintf(queue->name, sizeof(queue->name), "vif%s-q%u", 1618 devid, queue->id); 1619 1620 /* Initialise tx_skbs as a free chain containing every entry. */ 1621 queue->tx_skb_freelist = 0; 1622 for (i = 0; i < NET_TX_RING_SIZE; i++) { 1623 skb_entry_set_link(&queue->tx_skbs[i], i+1); 1624 queue->grant_tx_ref[i] = GRANT_INVALID_REF; 1625 queue->grant_tx_page[i] = NULL; 1626 } 1627 1628 /* Clear out rx_skbs */ 1629 for (i = 0; i < NET_RX_RING_SIZE; i++) { 1630 queue->rx_skbs[i] = NULL; 1631 queue->grant_rx_ref[i] = GRANT_INVALID_REF; 1632 } 1633 1634 /* A grant for every tx ring slot */ 1635 if (gnttab_alloc_grant_references(NET_TX_RING_SIZE, 1636 &queue->gref_tx_head) < 0) { 1637 pr_alert("can't alloc tx grant refs\n"); 1638 err = -ENOMEM; 1639 goto exit; 1640 } 1641 1642 /* A grant for every rx ring slot */ 1643 if (gnttab_alloc_grant_references(NET_RX_RING_SIZE, 1644 &queue->gref_rx_head) < 0) { 1645 pr_alert("can't alloc rx grant refs\n"); 1646 err = -ENOMEM; 1647 goto exit_free_tx; 1648 } 1649 1650 return 0; 1651 1652 exit_free_tx: 1653 gnttab_free_grant_references(queue->gref_tx_head); 1654 exit: 1655 return err; 1656 } 1657 1658 static int write_queue_xenstore_keys(struct netfront_queue *queue, 1659 struct xenbus_transaction *xbt, int write_hierarchical) 1660 { 1661 /* Write the queue-specific keys into XenStore in the traditional 1662 * way for a single queue, or in a queue subkeys for multiple 1663 * queues. 1664 */ 1665 struct xenbus_device *dev = queue->info->xbdev; 1666 int err; 1667 const char *message; 1668 char *path; 1669 size_t pathsize; 1670 1671 /* Choose the correct place to write the keys */ 1672 if (write_hierarchical) { 1673 pathsize = strlen(dev->nodename) + 10; 1674 path = kzalloc(pathsize, GFP_KERNEL); 1675 if (!path) { 1676 err = -ENOMEM; 1677 message = "out of memory while writing ring references"; 1678 goto error; 1679 } 1680 snprintf(path, pathsize, "%s/queue-%u", 1681 dev->nodename, queue->id); 1682 } else { 1683 path = (char *)dev->nodename; 1684 } 1685 1686 /* Write ring references */ 1687 err = xenbus_printf(*xbt, path, "tx-ring-ref", "%u", 1688 queue->tx_ring_ref); 1689 if (err) { 1690 message = "writing tx-ring-ref"; 1691 goto error; 1692 } 1693 1694 err = xenbus_printf(*xbt, path, "rx-ring-ref", "%u", 1695 queue->rx_ring_ref); 1696 if (err) { 1697 message = "writing rx-ring-ref"; 1698 goto error; 1699 } 1700 1701 /* Write event channels; taking into account both shared 1702 * and split event channel scenarios. 1703 */ 1704 if (queue->tx_evtchn == queue->rx_evtchn) { 1705 /* Shared event channel */ 1706 err = xenbus_printf(*xbt, path, 1707 "event-channel", "%u", queue->tx_evtchn); 1708 if (err) { 1709 message = "writing event-channel"; 1710 goto error; 1711 } 1712 } else { 1713 /* Split event channels */ 1714 err = xenbus_printf(*xbt, path, 1715 "event-channel-tx", "%u", queue->tx_evtchn); 1716 if (err) { 1717 message = "writing event-channel-tx"; 1718 goto error; 1719 } 1720 1721 err = xenbus_printf(*xbt, path, 1722 "event-channel-rx", "%u", queue->rx_evtchn); 1723 if (err) { 1724 message = "writing event-channel-rx"; 1725 goto error; 1726 } 1727 } 1728 1729 if (write_hierarchical) 1730 kfree(path); 1731 return 0; 1732 1733 error: 1734 if (write_hierarchical) 1735 kfree(path); 1736 xenbus_dev_fatal(dev, err, "%s", message); 1737 return err; 1738 } 1739 1740 static void xennet_destroy_queues(struct netfront_info *info) 1741 { 1742 unsigned int i; 1743 1744 for (i = 0; i < info->netdev->real_num_tx_queues; i++) { 1745 struct netfront_queue *queue = &info->queues[i]; 1746 1747 if (netif_running(info->netdev)) 1748 napi_disable(&queue->napi); 1749 netif_napi_del(&queue->napi); 1750 } 1751 1752 kfree(info->queues); 1753 info->queues = NULL; 1754 } 1755 1756 static int xennet_create_queues(struct netfront_info *info, 1757 unsigned int *num_queues) 1758 { 1759 unsigned int i; 1760 int ret; 1761 1762 info->queues = kcalloc(*num_queues, sizeof(struct netfront_queue), 1763 GFP_KERNEL); 1764 if (!info->queues) 1765 return -ENOMEM; 1766 1767 for (i = 0; i < *num_queues; i++) { 1768 struct netfront_queue *queue = &info->queues[i]; 1769 1770 queue->id = i; 1771 queue->info = info; 1772 1773 ret = xennet_init_queue(queue); 1774 if (ret < 0) { 1775 dev_warn(&info->xbdev->dev, 1776 "only created %d queues\n", i); 1777 *num_queues = i; 1778 break; 1779 } 1780 1781 netif_napi_add(queue->info->netdev, &queue->napi, 1782 xennet_poll, 64); 1783 if (netif_running(info->netdev)) 1784 napi_enable(&queue->napi); 1785 } 1786 1787 netif_set_real_num_tx_queues(info->netdev, *num_queues); 1788 1789 if (*num_queues == 0) { 1790 dev_err(&info->xbdev->dev, "no queues\n"); 1791 return -EINVAL; 1792 } 1793 return 0; 1794 } 1795 1796 /* Common code used when first setting up, and when resuming. */ 1797 static int talk_to_netback(struct xenbus_device *dev, 1798 struct netfront_info *info) 1799 { 1800 const char *message; 1801 struct xenbus_transaction xbt; 1802 int err; 1803 unsigned int feature_split_evtchn; 1804 unsigned int i = 0; 1805 unsigned int max_queues = 0; 1806 struct netfront_queue *queue = NULL; 1807 unsigned int num_queues = 1; 1808 1809 info->netdev->irq = 0; 1810 1811 /* Check if backend supports multiple queues */ 1812 max_queues = xenbus_read_unsigned(info->xbdev->otherend, 1813 "multi-queue-max-queues", 1); 1814 num_queues = min(max_queues, xennet_max_queues); 1815 1816 /* Check feature-split-event-channels */ 1817 feature_split_evtchn = xenbus_read_unsigned(info->xbdev->otherend, 1818 "feature-split-event-channels", 0); 1819 1820 /* Read mac addr. */ 1821 err = xen_net_read_mac(dev, info->netdev->dev_addr); 1822 if (err) { 1823 xenbus_dev_fatal(dev, err, "parsing %s/mac", dev->nodename); 1824 goto out_unlocked; 1825 } 1826 1827 rtnl_lock(); 1828 if (info->queues) 1829 xennet_destroy_queues(info); 1830 1831 err = xennet_create_queues(info, &num_queues); 1832 if (err < 0) { 1833 xenbus_dev_fatal(dev, err, "creating queues"); 1834 kfree(info->queues); 1835 info->queues = NULL; 1836 goto out; 1837 } 1838 rtnl_unlock(); 1839 1840 /* Create shared ring, alloc event channel -- for each queue */ 1841 for (i = 0; i < num_queues; ++i) { 1842 queue = &info->queues[i]; 1843 err = setup_netfront(dev, queue, feature_split_evtchn); 1844 if (err) 1845 goto destroy_ring; 1846 } 1847 1848 again: 1849 err = xenbus_transaction_start(&xbt); 1850 if (err) { 1851 xenbus_dev_fatal(dev, err, "starting transaction"); 1852 goto destroy_ring; 1853 } 1854 1855 if (xenbus_exists(XBT_NIL, 1856 info->xbdev->otherend, "multi-queue-max-queues")) { 1857 /* Write the number of queues */ 1858 err = xenbus_printf(xbt, dev->nodename, 1859 "multi-queue-num-queues", "%u", num_queues); 1860 if (err) { 1861 message = "writing multi-queue-num-queues"; 1862 goto abort_transaction_no_dev_fatal; 1863 } 1864 } 1865 1866 if (num_queues == 1) { 1867 err = write_queue_xenstore_keys(&info->queues[0], &xbt, 0); /* flat */ 1868 if (err) 1869 goto abort_transaction_no_dev_fatal; 1870 } else { 1871 /* Write the keys for each queue */ 1872 for (i = 0; i < num_queues; ++i) { 1873 queue = &info->queues[i]; 1874 err = write_queue_xenstore_keys(queue, &xbt, 1); /* hierarchical */ 1875 if (err) 1876 goto abort_transaction_no_dev_fatal; 1877 } 1878 } 1879 1880 /* The remaining keys are not queue-specific */ 1881 err = xenbus_printf(xbt, dev->nodename, "request-rx-copy", "%u", 1882 1); 1883 if (err) { 1884 message = "writing request-rx-copy"; 1885 goto abort_transaction; 1886 } 1887 1888 err = xenbus_printf(xbt, dev->nodename, "feature-rx-notify", "%d", 1); 1889 if (err) { 1890 message = "writing feature-rx-notify"; 1891 goto abort_transaction; 1892 } 1893 1894 err = xenbus_printf(xbt, dev->nodename, "feature-sg", "%d", 1); 1895 if (err) { 1896 message = "writing feature-sg"; 1897 goto abort_transaction; 1898 } 1899 1900 err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv4", "%d", 1); 1901 if (err) { 1902 message = "writing feature-gso-tcpv4"; 1903 goto abort_transaction; 1904 } 1905 1906 err = xenbus_write(xbt, dev->nodename, "feature-gso-tcpv6", "1"); 1907 if (err) { 1908 message = "writing feature-gso-tcpv6"; 1909 goto abort_transaction; 1910 } 1911 1912 err = xenbus_write(xbt, dev->nodename, "feature-ipv6-csum-offload", 1913 "1"); 1914 if (err) { 1915 message = "writing feature-ipv6-csum-offload"; 1916 goto abort_transaction; 1917 } 1918 1919 err = xenbus_transaction_end(xbt, 0); 1920 if (err) { 1921 if (err == -EAGAIN) 1922 goto again; 1923 xenbus_dev_fatal(dev, err, "completing transaction"); 1924 goto destroy_ring; 1925 } 1926 1927 return 0; 1928 1929 abort_transaction: 1930 xenbus_dev_fatal(dev, err, "%s", message); 1931 abort_transaction_no_dev_fatal: 1932 xenbus_transaction_end(xbt, 1); 1933 destroy_ring: 1934 xennet_disconnect_backend(info); 1935 rtnl_lock(); 1936 xennet_destroy_queues(info); 1937 out: 1938 rtnl_unlock(); 1939 out_unlocked: 1940 device_unregister(&dev->dev); 1941 return err; 1942 } 1943 1944 static int xennet_connect(struct net_device *dev) 1945 { 1946 struct netfront_info *np = netdev_priv(dev); 1947 unsigned int num_queues = 0; 1948 int err; 1949 unsigned int j = 0; 1950 struct netfront_queue *queue = NULL; 1951 1952 if (!xenbus_read_unsigned(np->xbdev->otherend, "feature-rx-copy", 0)) { 1953 dev_info(&dev->dev, 1954 "backend does not support copying receive path\n"); 1955 return -ENODEV; 1956 } 1957 1958 err = talk_to_netback(np->xbdev, np); 1959 if (err) 1960 return err; 1961 1962 /* talk_to_netback() sets the correct number of queues */ 1963 num_queues = dev->real_num_tx_queues; 1964 1965 if (dev->reg_state == NETREG_UNINITIALIZED) { 1966 err = register_netdev(dev); 1967 if (err) { 1968 pr_warn("%s: register_netdev err=%d\n", __func__, err); 1969 device_unregister(&np->xbdev->dev); 1970 return err; 1971 } 1972 } 1973 1974 rtnl_lock(); 1975 netdev_update_features(dev); 1976 rtnl_unlock(); 1977 1978 /* 1979 * All public and private state should now be sane. Get 1980 * ready to start sending and receiving packets and give the driver 1981 * domain a kick because we've probably just requeued some 1982 * packets. 1983 */ 1984 netif_carrier_on(np->netdev); 1985 for (j = 0; j < num_queues; ++j) { 1986 queue = &np->queues[j]; 1987 1988 notify_remote_via_irq(queue->tx_irq); 1989 if (queue->tx_irq != queue->rx_irq) 1990 notify_remote_via_irq(queue->rx_irq); 1991 1992 spin_lock_irq(&queue->tx_lock); 1993 xennet_tx_buf_gc(queue); 1994 spin_unlock_irq(&queue->tx_lock); 1995 1996 spin_lock_bh(&queue->rx_lock); 1997 xennet_alloc_rx_buffers(queue); 1998 spin_unlock_bh(&queue->rx_lock); 1999 } 2000 2001 return 0; 2002 } 2003 2004 /** 2005 * Callback received when the backend's state changes. 2006 */ 2007 static void netback_changed(struct xenbus_device *dev, 2008 enum xenbus_state backend_state) 2009 { 2010 struct netfront_info *np = dev_get_drvdata(&dev->dev); 2011 struct net_device *netdev = np->netdev; 2012 2013 dev_dbg(&dev->dev, "%s\n", xenbus_strstate(backend_state)); 2014 2015 wake_up_all(&module_wq); 2016 2017 switch (backend_state) { 2018 case XenbusStateInitialising: 2019 case XenbusStateInitialised: 2020 case XenbusStateReconfiguring: 2021 case XenbusStateReconfigured: 2022 case XenbusStateUnknown: 2023 break; 2024 2025 case XenbusStateInitWait: 2026 if (dev->state != XenbusStateInitialising) 2027 break; 2028 if (xennet_connect(netdev) != 0) 2029 break; 2030 xenbus_switch_state(dev, XenbusStateConnected); 2031 break; 2032 2033 case XenbusStateConnected: 2034 netdev_notify_peers(netdev); 2035 break; 2036 2037 case XenbusStateClosed: 2038 if (dev->state == XenbusStateClosed) 2039 break; 2040 /* Fall through - Missed the backend's CLOSING state. */ 2041 case XenbusStateClosing: 2042 xenbus_frontend_closed(dev); 2043 break; 2044 } 2045 } 2046 2047 static const struct xennet_stat { 2048 char name[ETH_GSTRING_LEN]; 2049 u16 offset; 2050 } xennet_stats[] = { 2051 { 2052 "rx_gso_checksum_fixup", 2053 offsetof(struct netfront_info, rx_gso_checksum_fixup) 2054 }, 2055 }; 2056 2057 static int xennet_get_sset_count(struct net_device *dev, int string_set) 2058 { 2059 switch (string_set) { 2060 case ETH_SS_STATS: 2061 return ARRAY_SIZE(xennet_stats); 2062 default: 2063 return -EINVAL; 2064 } 2065 } 2066 2067 static void xennet_get_ethtool_stats(struct net_device *dev, 2068 struct ethtool_stats *stats, u64 * data) 2069 { 2070 void *np = netdev_priv(dev); 2071 int i; 2072 2073 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++) 2074 data[i] = atomic_read((atomic_t *)(np + xennet_stats[i].offset)); 2075 } 2076 2077 static void xennet_get_strings(struct net_device *dev, u32 stringset, u8 * data) 2078 { 2079 int i; 2080 2081 switch (stringset) { 2082 case ETH_SS_STATS: 2083 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++) 2084 memcpy(data + i * ETH_GSTRING_LEN, 2085 xennet_stats[i].name, ETH_GSTRING_LEN); 2086 break; 2087 } 2088 } 2089 2090 static const struct ethtool_ops xennet_ethtool_ops = 2091 { 2092 .get_link = ethtool_op_get_link, 2093 2094 .get_sset_count = xennet_get_sset_count, 2095 .get_ethtool_stats = xennet_get_ethtool_stats, 2096 .get_strings = xennet_get_strings, 2097 }; 2098 2099 #ifdef CONFIG_SYSFS 2100 static ssize_t show_rxbuf(struct device *dev, 2101 struct device_attribute *attr, char *buf) 2102 { 2103 return sprintf(buf, "%lu\n", NET_RX_RING_SIZE); 2104 } 2105 2106 static ssize_t store_rxbuf(struct device *dev, 2107 struct device_attribute *attr, 2108 const char *buf, size_t len) 2109 { 2110 char *endp; 2111 unsigned long target; 2112 2113 if (!capable(CAP_NET_ADMIN)) 2114 return -EPERM; 2115 2116 target = simple_strtoul(buf, &endp, 0); 2117 if (endp == buf) 2118 return -EBADMSG; 2119 2120 /* rxbuf_min and rxbuf_max are no longer configurable. */ 2121 2122 return len; 2123 } 2124 2125 static DEVICE_ATTR(rxbuf_min, 0644, show_rxbuf, store_rxbuf); 2126 static DEVICE_ATTR(rxbuf_max, 0644, show_rxbuf, store_rxbuf); 2127 static DEVICE_ATTR(rxbuf_cur, 0444, show_rxbuf, NULL); 2128 2129 static struct attribute *xennet_dev_attrs[] = { 2130 &dev_attr_rxbuf_min.attr, 2131 &dev_attr_rxbuf_max.attr, 2132 &dev_attr_rxbuf_cur.attr, 2133 NULL 2134 }; 2135 2136 static const struct attribute_group xennet_dev_group = { 2137 .attrs = xennet_dev_attrs 2138 }; 2139 #endif /* CONFIG_SYSFS */ 2140 2141 static int xennet_remove(struct xenbus_device *dev) 2142 { 2143 struct netfront_info *info = dev_get_drvdata(&dev->dev); 2144 2145 dev_dbg(&dev->dev, "%s\n", dev->nodename); 2146 2147 if (xenbus_read_driver_state(dev->otherend) != XenbusStateClosed) { 2148 xenbus_switch_state(dev, XenbusStateClosing); 2149 wait_event(module_wq, 2150 xenbus_read_driver_state(dev->otherend) == 2151 XenbusStateClosing || 2152 xenbus_read_driver_state(dev->otherend) == 2153 XenbusStateUnknown); 2154 2155 xenbus_switch_state(dev, XenbusStateClosed); 2156 wait_event(module_wq, 2157 xenbus_read_driver_state(dev->otherend) == 2158 XenbusStateClosed || 2159 xenbus_read_driver_state(dev->otherend) == 2160 XenbusStateUnknown); 2161 } 2162 2163 xennet_disconnect_backend(info); 2164 2165 if (info->netdev->reg_state == NETREG_REGISTERED) 2166 unregister_netdev(info->netdev); 2167 2168 if (info->queues) { 2169 rtnl_lock(); 2170 xennet_destroy_queues(info); 2171 rtnl_unlock(); 2172 } 2173 xennet_free_netdev(info->netdev); 2174 2175 return 0; 2176 } 2177 2178 static const struct xenbus_device_id netfront_ids[] = { 2179 { "vif" }, 2180 { "" } 2181 }; 2182 2183 static struct xenbus_driver netfront_driver = { 2184 .ids = netfront_ids, 2185 .probe = netfront_probe, 2186 .remove = xennet_remove, 2187 .resume = netfront_resume, 2188 .otherend_changed = netback_changed, 2189 }; 2190 2191 static int __init netif_init(void) 2192 { 2193 if (!xen_domain()) 2194 return -ENODEV; 2195 2196 if (!xen_has_pv_nic_devices()) 2197 return -ENODEV; 2198 2199 pr_info("Initialising Xen virtual ethernet driver\n"); 2200 2201 /* Allow as many queues as there are CPUs inut max. 8 if user has not 2202 * specified a value. 2203 */ 2204 if (xennet_max_queues == 0) 2205 xennet_max_queues = min_t(unsigned int, MAX_QUEUES_DEFAULT, 2206 num_online_cpus()); 2207 2208 return xenbus_register_frontend(&netfront_driver); 2209 } 2210 module_init(netif_init); 2211 2212 2213 static void __exit netif_exit(void) 2214 { 2215 xenbus_unregister_driver(&netfront_driver); 2216 } 2217 module_exit(netif_exit); 2218 2219 MODULE_DESCRIPTION("Xen virtual network device frontend"); 2220 MODULE_LICENSE("GPL"); 2221 MODULE_ALIAS("xen:vif"); 2222 MODULE_ALIAS("xennet"); 2223