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 static unsigned int xennet_max_queues;
61 module_param_named(max_queues, xennet_max_queues, uint, 0644);
62 MODULE_PARM_DESC(max_queues,
63 "Maximum number of queues per virtual interface");
64
65 #define XENNET_TIMEOUT (5 * HZ)
66
67 static const struct ethtool_ops xennet_ethtool_ops;
68
69 struct netfront_cb {
70 int pull_to;
71 };
72
73 #define NETFRONT_SKB_CB(skb) ((struct netfront_cb *)((skb)->cb))
74
75 #define RX_COPY_THRESHOLD 256
76
77 #define GRANT_INVALID_REF 0
78
79 #define NET_TX_RING_SIZE __CONST_RING_SIZE(xen_netif_tx, XEN_PAGE_SIZE)
80 #define NET_RX_RING_SIZE __CONST_RING_SIZE(xen_netif_rx, XEN_PAGE_SIZE)
81
82 /* Minimum number of Rx slots (includes slot for GSO metadata). */
83 #define NET_RX_SLOTS_MIN (XEN_NETIF_NR_SLOTS_MIN + 1)
84
85 /* Queue name is interface name with "-qNNN" appended */
86 #define QUEUE_NAME_SIZE (IFNAMSIZ + 6)
87
88 /* IRQ name is queue name with "-tx" or "-rx" appended */
89 #define IRQ_NAME_SIZE (QUEUE_NAME_SIZE + 3)
90
91 static DECLARE_WAIT_QUEUE_HEAD(module_wq);
92
93 struct netfront_stats {
94 u64 packets;
95 u64 bytes;
96 struct u64_stats_sync syncp;
97 };
98
99 struct netfront_info;
100
101 struct netfront_queue {
102 unsigned int id; /* Queue ID, 0-based */
103 char name[QUEUE_NAME_SIZE]; /* DEVNAME-qN */
104 struct netfront_info *info;
105
106 struct napi_struct napi;
107
108 /* Split event channels support, tx_* == rx_* when using
109 * single event channel.
110 */
111 unsigned int tx_evtchn, rx_evtchn;
112 unsigned int tx_irq, rx_irq;
113 /* Only used when split event channels support is enabled */
114 char tx_irq_name[IRQ_NAME_SIZE]; /* DEVNAME-qN-tx */
115 char rx_irq_name[IRQ_NAME_SIZE]; /* DEVNAME-qN-rx */
116
117 spinlock_t tx_lock;
118 struct xen_netif_tx_front_ring tx;
119 int tx_ring_ref;
120
121 /*
122 * {tx,rx}_skbs store outstanding skbuffs. Free tx_skb entries
123 * are linked from tx_skb_freelist through tx_link.
124 */
125 struct sk_buff *tx_skbs[NET_TX_RING_SIZE];
126 unsigned short tx_link[NET_TX_RING_SIZE];
127 #define TX_LINK_NONE 0xffff
128 #define TX_PENDING 0xfffe
129 grant_ref_t gref_tx_head;
130 grant_ref_t grant_tx_ref[NET_TX_RING_SIZE];
131 struct page *grant_tx_page[NET_TX_RING_SIZE];
132 unsigned tx_skb_freelist;
133 unsigned int tx_pend_queue;
134
135 spinlock_t rx_lock ____cacheline_aligned_in_smp;
136 struct xen_netif_rx_front_ring rx;
137 int rx_ring_ref;
138
139 struct timer_list rx_refill_timer;
140
141 struct sk_buff *rx_skbs[NET_RX_RING_SIZE];
142 grant_ref_t gref_rx_head;
143 grant_ref_t grant_rx_ref[NET_RX_RING_SIZE];
144
145 unsigned int rx_rsp_unconsumed;
146 spinlock_t rx_cons_lock;
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 /* Is device behaving sane? */
163 bool broken;
164
165 atomic_t rx_gso_checksum_fixup;
166 };
167
168 struct netfront_rx_info {
169 struct xen_netif_rx_response rx;
170 struct xen_netif_extra_info extras[XEN_NETIF_EXTRA_TYPE_MAX - 1];
171 };
172
173 /*
174 * Access macros for acquiring freeing slots in tx_skbs[].
175 */
176
add_id_to_list(unsigned * head,unsigned short * list,unsigned short id)177 static void add_id_to_list(unsigned *head, unsigned short *list,
178 unsigned short id)
179 {
180 list[id] = *head;
181 *head = id;
182 }
183
get_id_from_list(unsigned * head,unsigned short * list)184 static unsigned short get_id_from_list(unsigned *head, unsigned short *list)
185 {
186 unsigned int id = *head;
187
188 if (id != TX_LINK_NONE) {
189 *head = list[id];
190 list[id] = TX_LINK_NONE;
191 }
192 return id;
193 }
194
xennet_rxidx(RING_IDX idx)195 static int xennet_rxidx(RING_IDX idx)
196 {
197 return idx & (NET_RX_RING_SIZE - 1);
198 }
199
xennet_get_rx_skb(struct netfront_queue * queue,RING_IDX ri)200 static struct sk_buff *xennet_get_rx_skb(struct netfront_queue *queue,
201 RING_IDX ri)
202 {
203 int i = xennet_rxidx(ri);
204 struct sk_buff *skb = queue->rx_skbs[i];
205 queue->rx_skbs[i] = NULL;
206 return skb;
207 }
208
xennet_get_rx_ref(struct netfront_queue * queue,RING_IDX ri)209 static grant_ref_t xennet_get_rx_ref(struct netfront_queue *queue,
210 RING_IDX ri)
211 {
212 int i = xennet_rxidx(ri);
213 grant_ref_t ref = queue->grant_rx_ref[i];
214 queue->grant_rx_ref[i] = GRANT_INVALID_REF;
215 return ref;
216 }
217
218 #ifdef CONFIG_SYSFS
219 static const struct attribute_group xennet_dev_group;
220 #endif
221
xennet_can_sg(struct net_device * dev)222 static bool xennet_can_sg(struct net_device *dev)
223 {
224 return dev->features & NETIF_F_SG;
225 }
226
227
rx_refill_timeout(unsigned long data)228 static void rx_refill_timeout(unsigned long data)
229 {
230 struct netfront_queue *queue = (struct netfront_queue *)data;
231 napi_schedule(&queue->napi);
232 }
233
netfront_tx_slot_available(struct netfront_queue * queue)234 static int netfront_tx_slot_available(struct netfront_queue *queue)
235 {
236 return (queue->tx.req_prod_pvt - queue->tx.rsp_cons) <
237 (NET_TX_RING_SIZE - XEN_NETIF_NR_SLOTS_MIN - 1);
238 }
239
xennet_maybe_wake_tx(struct netfront_queue * queue)240 static void xennet_maybe_wake_tx(struct netfront_queue *queue)
241 {
242 struct net_device *dev = queue->info->netdev;
243 struct netdev_queue *dev_queue = netdev_get_tx_queue(dev, queue->id);
244
245 if (unlikely(netif_tx_queue_stopped(dev_queue)) &&
246 netfront_tx_slot_available(queue) &&
247 likely(netif_running(dev)))
248 netif_tx_wake_queue(netdev_get_tx_queue(dev, queue->id));
249 }
250
251
xennet_alloc_one_rx_buffer(struct netfront_queue * queue)252 static struct sk_buff *xennet_alloc_one_rx_buffer(struct netfront_queue *queue)
253 {
254 struct sk_buff *skb;
255 struct page *page;
256
257 skb = __netdev_alloc_skb(queue->info->netdev,
258 RX_COPY_THRESHOLD + NET_IP_ALIGN,
259 GFP_ATOMIC | __GFP_NOWARN);
260 if (unlikely(!skb))
261 return NULL;
262
263 page = alloc_page(GFP_ATOMIC | __GFP_NOWARN);
264 if (!page) {
265 kfree_skb(skb);
266 return NULL;
267 }
268 skb_add_rx_frag(skb, 0, page, 0, 0, PAGE_SIZE);
269
270 /* Align ip header to a 16 bytes boundary */
271 skb_reserve(skb, NET_IP_ALIGN);
272 skb->dev = queue->info->netdev;
273
274 return skb;
275 }
276
277
xennet_alloc_rx_buffers(struct netfront_queue * queue)278 static void xennet_alloc_rx_buffers(struct netfront_queue *queue)
279 {
280 RING_IDX req_prod = queue->rx.req_prod_pvt;
281 int notify;
282 int err = 0;
283
284 if (unlikely(!netif_carrier_ok(queue->info->netdev)))
285 return;
286
287 for (req_prod = queue->rx.req_prod_pvt;
288 req_prod - queue->rx.rsp_cons < NET_RX_RING_SIZE;
289 req_prod++) {
290 struct sk_buff *skb;
291 unsigned short id;
292 grant_ref_t ref;
293 struct page *page;
294 struct xen_netif_rx_request *req;
295
296 skb = xennet_alloc_one_rx_buffer(queue);
297 if (!skb) {
298 err = -ENOMEM;
299 break;
300 }
301
302 id = xennet_rxidx(req_prod);
303
304 BUG_ON(queue->rx_skbs[id]);
305 queue->rx_skbs[id] = skb;
306
307 ref = gnttab_claim_grant_reference(&queue->gref_rx_head);
308 WARN_ON_ONCE(IS_ERR_VALUE((unsigned long)(int)ref));
309 queue->grant_rx_ref[id] = ref;
310
311 page = skb_frag_page(&skb_shinfo(skb)->frags[0]);
312
313 req = RING_GET_REQUEST(&queue->rx, req_prod);
314 gnttab_page_grant_foreign_access_ref_one(ref,
315 queue->info->xbdev->otherend_id,
316 page,
317 0);
318 req->id = id;
319 req->gref = ref;
320 }
321
322 queue->rx.req_prod_pvt = req_prod;
323
324 /* Try again later if there are not enough requests or skb allocation
325 * failed.
326 * Enough requests is quantified as the sum of newly created slots and
327 * the unconsumed slots at the backend.
328 */
329 if (req_prod - queue->rx.rsp_cons < NET_RX_SLOTS_MIN ||
330 unlikely(err)) {
331 mod_timer(&queue->rx_refill_timer, jiffies + (HZ/10));
332 return;
333 }
334
335 wmb(); /* barrier so backend seens requests */
336
337 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->rx, notify);
338 if (notify)
339 notify_remote_via_irq(queue->rx_irq);
340 }
341
xennet_open(struct net_device * dev)342 static int xennet_open(struct net_device *dev)
343 {
344 struct netfront_info *np = netdev_priv(dev);
345 unsigned int num_queues = dev->real_num_tx_queues;
346 unsigned int i = 0;
347 struct netfront_queue *queue = NULL;
348
349 if (!np->queues || np->broken)
350 return -ENODEV;
351
352 for (i = 0; i < num_queues; ++i) {
353 queue = &np->queues[i];
354 napi_enable(&queue->napi);
355
356 spin_lock_bh(&queue->rx_lock);
357 if (netif_carrier_ok(dev)) {
358 xennet_alloc_rx_buffers(queue);
359 queue->rx.sring->rsp_event = queue->rx.rsp_cons + 1;
360 if (RING_HAS_UNCONSUMED_RESPONSES(&queue->rx))
361 napi_schedule(&queue->napi);
362 }
363 spin_unlock_bh(&queue->rx_lock);
364 }
365
366 netif_tx_start_all_queues(dev);
367
368 return 0;
369 }
370
xennet_tx_buf_gc(struct netfront_queue * queue)371 static bool xennet_tx_buf_gc(struct netfront_queue *queue)
372 {
373 RING_IDX cons, prod;
374 unsigned short id;
375 struct sk_buff *skb;
376 bool work_done = false;
377 const struct device *dev = &queue->info->netdev->dev;
378
379 BUG_ON(!netif_carrier_ok(queue->info->netdev));
380
381 do {
382 prod = queue->tx.sring->rsp_prod;
383 if (RING_RESPONSE_PROD_OVERFLOW(&queue->tx, prod)) {
384 dev_alert(dev, "Illegal number of responses %u\n",
385 prod - queue->tx.rsp_cons);
386 goto err;
387 }
388 rmb(); /* Ensure we see responses up to 'rp'. */
389
390 for (cons = queue->tx.rsp_cons; cons != prod; cons++) {
391 struct xen_netif_tx_response txrsp;
392
393 work_done = true;
394
395 RING_COPY_RESPONSE(&queue->tx, cons, &txrsp);
396 if (txrsp.status == XEN_NETIF_RSP_NULL)
397 continue;
398
399 id = txrsp.id;
400 if (id >= RING_SIZE(&queue->tx)) {
401 dev_alert(dev,
402 "Response has incorrect id (%u)\n",
403 id);
404 goto err;
405 }
406 if (queue->tx_link[id] != TX_PENDING) {
407 dev_alert(dev,
408 "Response for inactive request\n");
409 goto err;
410 }
411
412 queue->tx_link[id] = TX_LINK_NONE;
413 skb = queue->tx_skbs[id];
414 queue->tx_skbs[id] = NULL;
415 if (unlikely(gnttab_query_foreign_access(
416 queue->grant_tx_ref[id]) != 0)) {
417 dev_alert(dev,
418 "Grant still in use by backend domain\n");
419 goto err;
420 }
421 gnttab_end_foreign_access_ref(
422 queue->grant_tx_ref[id], GNTMAP_readonly);
423 gnttab_release_grant_reference(
424 &queue->gref_tx_head, queue->grant_tx_ref[id]);
425 queue->grant_tx_ref[id] = GRANT_INVALID_REF;
426 queue->grant_tx_page[id] = NULL;
427 add_id_to_list(&queue->tx_skb_freelist, queue->tx_link, id);
428 dev_kfree_skb_irq(skb);
429 }
430
431 queue->tx.rsp_cons = prod;
432
433 /*
434 * Set a new event, then check for race with update of tx_cons.
435 * Note that it is essential to schedule a callback, no matter
436 * how few buffers are pending. Even if there is space in the
437 * transmit ring, higher layers may be blocked because too much
438 * data is outstanding: in such cases notification from Xen is
439 * likely to be the only kick that we'll get.
440 */
441 queue->tx.sring->rsp_event =
442 prod + ((queue->tx.sring->req_prod - prod) >> 1) + 1;
443 mb(); /* update shared area */
444 } while ((cons == prod) && (prod != queue->tx.sring->rsp_prod));
445
446 xennet_maybe_wake_tx(queue);
447
448 return work_done;
449
450 err:
451 queue->info->broken = true;
452 dev_alert(dev, "Disabled for further use\n");
453
454 return work_done;
455 }
456
457 struct xennet_gnttab_make_txreq {
458 struct netfront_queue *queue;
459 struct sk_buff *skb;
460 struct page *page;
461 struct xen_netif_tx_request *tx; /* Last request on ring page */
462 struct xen_netif_tx_request tx_local; /* Last request local copy*/
463 unsigned int size;
464 };
465
xennet_tx_setup_grant(unsigned long gfn,unsigned int offset,unsigned int len,void * data)466 static void xennet_tx_setup_grant(unsigned long gfn, unsigned int offset,
467 unsigned int len, void *data)
468 {
469 struct xennet_gnttab_make_txreq *info = data;
470 unsigned int id;
471 struct xen_netif_tx_request *tx;
472 grant_ref_t ref;
473 /* convenient aliases */
474 struct page *page = info->page;
475 struct netfront_queue *queue = info->queue;
476 struct sk_buff *skb = info->skb;
477
478 id = get_id_from_list(&queue->tx_skb_freelist, queue->tx_link);
479 tx = RING_GET_REQUEST(&queue->tx, queue->tx.req_prod_pvt++);
480 ref = gnttab_claim_grant_reference(&queue->gref_tx_head);
481 WARN_ON_ONCE(IS_ERR_VALUE((unsigned long)(int)ref));
482
483 gnttab_grant_foreign_access_ref(ref, queue->info->xbdev->otherend_id,
484 gfn, GNTMAP_readonly);
485
486 queue->tx_skbs[id] = skb;
487 queue->grant_tx_page[id] = page;
488 queue->grant_tx_ref[id] = ref;
489
490 info->tx_local.id = id;
491 info->tx_local.gref = ref;
492 info->tx_local.offset = offset;
493 info->tx_local.size = len;
494 info->tx_local.flags = 0;
495
496 *tx = info->tx_local;
497
498 /*
499 * Put the request in the pending queue, it will be set to be pending
500 * when the producer index is about to be raised.
501 */
502 add_id_to_list(&queue->tx_pend_queue, queue->tx_link, id);
503
504 info->tx = tx;
505 info->size += info->tx_local.size;
506 }
507
xennet_make_first_txreq(struct xennet_gnttab_make_txreq * info,unsigned int offset,unsigned int len)508 static struct xen_netif_tx_request *xennet_make_first_txreq(
509 struct xennet_gnttab_make_txreq *info,
510 unsigned int offset, unsigned int len)
511 {
512 info->size = 0;
513
514 gnttab_for_one_grant(info->page, offset, len, xennet_tx_setup_grant, info);
515
516 return info->tx;
517 }
518
xennet_make_one_txreq(unsigned long gfn,unsigned int offset,unsigned int len,void * data)519 static void xennet_make_one_txreq(unsigned long gfn, unsigned int offset,
520 unsigned int len, void *data)
521 {
522 struct xennet_gnttab_make_txreq *info = data;
523
524 info->tx->flags |= XEN_NETTXF_more_data;
525 skb_get(info->skb);
526 xennet_tx_setup_grant(gfn, offset, len, data);
527 }
528
xennet_make_txreqs(struct xennet_gnttab_make_txreq * info,struct page * page,unsigned int offset,unsigned int len)529 static void xennet_make_txreqs(
530 struct xennet_gnttab_make_txreq *info,
531 struct page *page,
532 unsigned int offset, unsigned int len)
533 {
534 /* Skip unused frames from start of page */
535 page += offset >> PAGE_SHIFT;
536 offset &= ~PAGE_MASK;
537
538 while (len) {
539 info->page = page;
540 info->size = 0;
541
542 gnttab_foreach_grant_in_range(page, offset, len,
543 xennet_make_one_txreq,
544 info);
545
546 page++;
547 offset = 0;
548 len -= info->size;
549 }
550 }
551
552 /*
553 * Count how many ring slots are required to send this skb. Each frag
554 * might be a compound page.
555 */
xennet_count_skb_slots(struct sk_buff * skb)556 static int xennet_count_skb_slots(struct sk_buff *skb)
557 {
558 int i, frags = skb_shinfo(skb)->nr_frags;
559 int slots;
560
561 slots = gnttab_count_grant(offset_in_page(skb->data),
562 skb_headlen(skb));
563
564 for (i = 0; i < frags; i++) {
565 skb_frag_t *frag = skb_shinfo(skb)->frags + i;
566 unsigned long size = skb_frag_size(frag);
567 unsigned long offset = frag->page_offset;
568
569 /* Skip unused frames from start of page */
570 offset &= ~PAGE_MASK;
571
572 slots += gnttab_count_grant(offset, size);
573 }
574
575 return slots;
576 }
577
xennet_select_queue(struct net_device * dev,struct sk_buff * skb,void * accel_priv,select_queue_fallback_t fallback)578 static u16 xennet_select_queue(struct net_device *dev, struct sk_buff *skb,
579 void *accel_priv, select_queue_fallback_t fallback)
580 {
581 unsigned int num_queues = dev->real_num_tx_queues;
582 u32 hash;
583 u16 queue_idx;
584
585 /* First, check if there is only one queue */
586 if (num_queues == 1) {
587 queue_idx = 0;
588 } else {
589 hash = skb_get_hash(skb);
590 queue_idx = hash % num_queues;
591 }
592
593 return queue_idx;
594 }
595
xennet_mark_tx_pending(struct netfront_queue * queue)596 static void xennet_mark_tx_pending(struct netfront_queue *queue)
597 {
598 unsigned int i;
599
600 while ((i = get_id_from_list(&queue->tx_pend_queue, queue->tx_link)) !=
601 TX_LINK_NONE)
602 queue->tx_link[i] = TX_PENDING;
603 }
604
605 #define MAX_XEN_SKB_FRAGS (65536 / XEN_PAGE_SIZE + 1)
606
xennet_start_xmit(struct sk_buff * skb,struct net_device * dev)607 static int xennet_start_xmit(struct sk_buff *skb, struct net_device *dev)
608 {
609 struct netfront_info *np = netdev_priv(dev);
610 struct netfront_stats *tx_stats = this_cpu_ptr(np->tx_stats);
611 struct xen_netif_tx_request *first_tx;
612 unsigned int i;
613 int notify;
614 int slots;
615 struct page *page;
616 unsigned int offset;
617 unsigned int len;
618 unsigned long flags;
619 struct netfront_queue *queue = NULL;
620 struct xennet_gnttab_make_txreq info = { };
621 unsigned int num_queues = dev->real_num_tx_queues;
622 u16 queue_index;
623
624 /* Drop the packet if no queues are set up */
625 if (num_queues < 1)
626 goto drop;
627 if (unlikely(np->broken))
628 goto drop;
629 /* Determine which queue to transmit this SKB on */
630 queue_index = skb_get_queue_mapping(skb);
631 queue = &np->queues[queue_index];
632
633 /* If skb->len is too big for wire format, drop skb and alert
634 * user about misconfiguration.
635 */
636 if (unlikely(skb->len > XEN_NETIF_MAX_TX_SIZE)) {
637 net_alert_ratelimited(
638 "xennet: skb->len = %u, too big for wire format\n",
639 skb->len);
640 goto drop;
641 }
642
643 slots = xennet_count_skb_slots(skb);
644 if (unlikely(slots > MAX_XEN_SKB_FRAGS + 1)) {
645 net_dbg_ratelimited("xennet: skb rides the rocket: %d slots, %d bytes\n",
646 slots, skb->len);
647 if (skb_linearize(skb))
648 goto drop;
649 }
650
651 page = virt_to_page(skb->data);
652 offset = offset_in_page(skb->data);
653 len = skb_headlen(skb);
654
655 spin_lock_irqsave(&queue->tx_lock, flags);
656
657 if (unlikely(!netif_carrier_ok(dev) ||
658 (slots > 1 && !xennet_can_sg(dev)) ||
659 netif_needs_gso(skb, netif_skb_features(skb)))) {
660 spin_unlock_irqrestore(&queue->tx_lock, flags);
661 goto drop;
662 }
663
664 /* First request for the linear area. */
665 info.queue = queue;
666 info.skb = skb;
667 info.page = page;
668 first_tx = xennet_make_first_txreq(&info, offset, len);
669 offset += info.tx_local.size;
670 if (offset == PAGE_SIZE) {
671 page++;
672 offset = 0;
673 }
674 len -= info.tx_local.size;
675
676 if (skb->ip_summed == CHECKSUM_PARTIAL)
677 /* local packet? */
678 first_tx->flags |= XEN_NETTXF_csum_blank |
679 XEN_NETTXF_data_validated;
680 else if (skb->ip_summed == CHECKSUM_UNNECESSARY)
681 /* remote but checksummed. */
682 first_tx->flags |= XEN_NETTXF_data_validated;
683
684 /* Optional extra info after the first request. */
685 if (skb_shinfo(skb)->gso_size) {
686 struct xen_netif_extra_info *gso;
687
688 gso = (struct xen_netif_extra_info *)
689 RING_GET_REQUEST(&queue->tx, queue->tx.req_prod_pvt++);
690
691 first_tx->flags |= XEN_NETTXF_extra_info;
692
693 gso->u.gso.size = skb_shinfo(skb)->gso_size;
694 gso->u.gso.type = (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6) ?
695 XEN_NETIF_GSO_TYPE_TCPV6 :
696 XEN_NETIF_GSO_TYPE_TCPV4;
697 gso->u.gso.pad = 0;
698 gso->u.gso.features = 0;
699
700 gso->type = XEN_NETIF_EXTRA_TYPE_GSO;
701 gso->flags = 0;
702 }
703
704 /* Requests for the rest of the linear area. */
705 xennet_make_txreqs(&info, page, offset, len);
706
707 /* Requests for all the frags. */
708 for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
709 skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
710 xennet_make_txreqs(&info, skb_frag_page(frag),
711 frag->page_offset,
712 skb_frag_size(frag));
713 }
714
715 /* First request has the packet length. */
716 first_tx->size = skb->len;
717
718 xennet_mark_tx_pending(queue);
719
720 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->tx, notify);
721 if (notify)
722 notify_remote_via_irq(queue->tx_irq);
723
724 u64_stats_update_begin(&tx_stats->syncp);
725 tx_stats->bytes += skb->len;
726 tx_stats->packets++;
727 u64_stats_update_end(&tx_stats->syncp);
728
729 /* Note: It is not safe to access skb after xennet_tx_buf_gc()! */
730 xennet_tx_buf_gc(queue);
731
732 if (!netfront_tx_slot_available(queue))
733 netif_tx_stop_queue(netdev_get_tx_queue(dev, queue->id));
734
735 spin_unlock_irqrestore(&queue->tx_lock, flags);
736
737 return NETDEV_TX_OK;
738
739 drop:
740 dev->stats.tx_dropped++;
741 dev_kfree_skb_any(skb);
742 return NETDEV_TX_OK;
743 }
744
xennet_close(struct net_device * dev)745 static int xennet_close(struct net_device *dev)
746 {
747 struct netfront_info *np = netdev_priv(dev);
748 unsigned int num_queues = dev->real_num_tx_queues;
749 unsigned int i;
750 struct netfront_queue *queue;
751 netif_tx_stop_all_queues(np->netdev);
752 for (i = 0; i < num_queues; ++i) {
753 queue = &np->queues[i];
754 napi_disable(&queue->napi);
755 }
756 return 0;
757 }
758
xennet_set_rx_rsp_cons(struct netfront_queue * queue,RING_IDX val)759 static void xennet_set_rx_rsp_cons(struct netfront_queue *queue, RING_IDX val)
760 {
761 unsigned long flags;
762
763 spin_lock_irqsave(&queue->rx_cons_lock, flags);
764 queue->rx.rsp_cons = val;
765 queue->rx_rsp_unconsumed = RING_HAS_UNCONSUMED_RESPONSES(&queue->rx);
766 spin_unlock_irqrestore(&queue->rx_cons_lock, flags);
767 }
768
xennet_move_rx_slot(struct netfront_queue * queue,struct sk_buff * skb,grant_ref_t ref)769 static void xennet_move_rx_slot(struct netfront_queue *queue, struct sk_buff *skb,
770 grant_ref_t ref)
771 {
772 int new = xennet_rxidx(queue->rx.req_prod_pvt);
773
774 BUG_ON(queue->rx_skbs[new]);
775 queue->rx_skbs[new] = skb;
776 queue->grant_rx_ref[new] = ref;
777 RING_GET_REQUEST(&queue->rx, queue->rx.req_prod_pvt)->id = new;
778 RING_GET_REQUEST(&queue->rx, queue->rx.req_prod_pvt)->gref = ref;
779 queue->rx.req_prod_pvt++;
780 }
781
xennet_get_extras(struct netfront_queue * queue,struct xen_netif_extra_info * extras,RING_IDX rp)782 static int xennet_get_extras(struct netfront_queue *queue,
783 struct xen_netif_extra_info *extras,
784 RING_IDX rp)
785
786 {
787 struct xen_netif_extra_info extra;
788 struct device *dev = &queue->info->netdev->dev;
789 RING_IDX cons = queue->rx.rsp_cons;
790 int err = 0;
791
792 do {
793 struct sk_buff *skb;
794 grant_ref_t ref;
795
796 if (unlikely(cons + 1 == rp)) {
797 if (net_ratelimit())
798 dev_warn(dev, "Missing extra info\n");
799 err = -EBADR;
800 break;
801 }
802
803 RING_COPY_RESPONSE(&queue->rx, ++cons, &extra);
804
805 if (unlikely(!extra.type ||
806 extra.type >= XEN_NETIF_EXTRA_TYPE_MAX)) {
807 if (net_ratelimit())
808 dev_warn(dev, "Invalid extra type: %d\n",
809 extra.type);
810 err = -EINVAL;
811 } else {
812 extras[extra.type - 1] = extra;
813 }
814
815 skb = xennet_get_rx_skb(queue, cons);
816 ref = xennet_get_rx_ref(queue, cons);
817 xennet_move_rx_slot(queue, skb, ref);
818 } while (extra.flags & XEN_NETIF_EXTRA_FLAG_MORE);
819
820 xennet_set_rx_rsp_cons(queue, cons);
821 return err;
822 }
823
xennet_get_responses(struct netfront_queue * queue,struct netfront_rx_info * rinfo,RING_IDX rp,struct sk_buff_head * list)824 static int xennet_get_responses(struct netfront_queue *queue,
825 struct netfront_rx_info *rinfo, RING_IDX rp,
826 struct sk_buff_head *list)
827 {
828 struct xen_netif_rx_response *rx = &rinfo->rx, rx_local;
829 struct xen_netif_extra_info *extras = rinfo->extras;
830 struct device *dev = &queue->info->netdev->dev;
831 RING_IDX cons = queue->rx.rsp_cons;
832 struct sk_buff *skb = xennet_get_rx_skb(queue, cons);
833 grant_ref_t ref = xennet_get_rx_ref(queue, cons);
834 int max = XEN_NETIF_NR_SLOTS_MIN + (rx->status <= RX_COPY_THRESHOLD);
835 int slots = 1;
836 int err = 0;
837 unsigned long ret;
838
839 if (rx->flags & XEN_NETRXF_extra_info) {
840 err = xennet_get_extras(queue, extras, rp);
841 cons = queue->rx.rsp_cons;
842 }
843
844 for (;;) {
845 if (unlikely(rx->status < 0 ||
846 rx->offset + rx->status > XEN_PAGE_SIZE)) {
847 if (net_ratelimit())
848 dev_warn(dev, "rx->offset: %u, size: %d\n",
849 rx->offset, rx->status);
850 xennet_move_rx_slot(queue, skb, ref);
851 err = -EINVAL;
852 goto next;
853 }
854
855 /*
856 * This definitely indicates a bug, either in this driver or in
857 * the backend driver. In future this should flag the bad
858 * situation to the system controller to reboot the backend.
859 */
860 if (ref == GRANT_INVALID_REF) {
861 if (net_ratelimit())
862 dev_warn(dev, "Bad rx response id %d.\n",
863 rx->id);
864 err = -EINVAL;
865 goto next;
866 }
867
868 ret = gnttab_end_foreign_access_ref(ref, 0);
869 BUG_ON(!ret);
870
871 gnttab_release_grant_reference(&queue->gref_rx_head, ref);
872
873 __skb_queue_tail(list, skb);
874
875 next:
876 if (!(rx->flags & XEN_NETRXF_more_data))
877 break;
878
879 if (cons + slots == rp) {
880 if (net_ratelimit())
881 dev_warn(dev, "Need more slots\n");
882 err = -ENOENT;
883 break;
884 }
885
886 RING_COPY_RESPONSE(&queue->rx, cons + slots, &rx_local);
887 rx = &rx_local;
888 skb = xennet_get_rx_skb(queue, cons + slots);
889 ref = xennet_get_rx_ref(queue, cons + slots);
890 slots++;
891 }
892
893 if (unlikely(slots > max)) {
894 if (net_ratelimit())
895 dev_warn(dev, "Too many slots\n");
896 err = -E2BIG;
897 }
898
899 if (unlikely(err))
900 xennet_set_rx_rsp_cons(queue, cons + slots);
901
902 return err;
903 }
904
xennet_set_skb_gso(struct sk_buff * skb,struct xen_netif_extra_info * gso)905 static int xennet_set_skb_gso(struct sk_buff *skb,
906 struct xen_netif_extra_info *gso)
907 {
908 if (!gso->u.gso.size) {
909 if (net_ratelimit())
910 pr_warn("GSO size must not be zero\n");
911 return -EINVAL;
912 }
913
914 if (gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV4 &&
915 gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV6) {
916 if (net_ratelimit())
917 pr_warn("Bad GSO type %d\n", gso->u.gso.type);
918 return -EINVAL;
919 }
920
921 skb_shinfo(skb)->gso_size = gso->u.gso.size;
922 skb_shinfo(skb)->gso_type =
923 (gso->u.gso.type == XEN_NETIF_GSO_TYPE_TCPV4) ?
924 SKB_GSO_TCPV4 :
925 SKB_GSO_TCPV6;
926
927 /* Header must be checked, and gso_segs computed. */
928 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
929 skb_shinfo(skb)->gso_segs = 0;
930
931 return 0;
932 }
933
xennet_fill_frags(struct netfront_queue * queue,struct sk_buff * skb,struct sk_buff_head * list)934 static int xennet_fill_frags(struct netfront_queue *queue,
935 struct sk_buff *skb,
936 struct sk_buff_head *list)
937 {
938 RING_IDX cons = queue->rx.rsp_cons;
939 struct sk_buff *nskb;
940
941 while ((nskb = __skb_dequeue(list))) {
942 struct xen_netif_rx_response rx;
943 skb_frag_t *nfrag = &skb_shinfo(nskb)->frags[0];
944
945 RING_COPY_RESPONSE(&queue->rx, ++cons, &rx);
946
947 if (skb_shinfo(skb)->nr_frags == MAX_SKB_FRAGS) {
948 unsigned int pull_to = NETFRONT_SKB_CB(skb)->pull_to;
949
950 BUG_ON(pull_to < skb_headlen(skb));
951 __pskb_pull_tail(skb, pull_to - skb_headlen(skb));
952 }
953 if (unlikely(skb_shinfo(skb)->nr_frags >= MAX_SKB_FRAGS)) {
954 xennet_set_rx_rsp_cons(queue,
955 ++cons + skb_queue_len(list));
956 kfree_skb(nskb);
957 return -ENOENT;
958 }
959
960 skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags,
961 skb_frag_page(nfrag),
962 rx.offset, rx.status, PAGE_SIZE);
963
964 skb_shinfo(nskb)->nr_frags = 0;
965 kfree_skb(nskb);
966 }
967
968 xennet_set_rx_rsp_cons(queue, cons);
969
970 return 0;
971 }
972
checksum_setup(struct net_device * dev,struct sk_buff * skb)973 static int checksum_setup(struct net_device *dev, struct sk_buff *skb)
974 {
975 bool recalculate_partial_csum = false;
976
977 /*
978 * A GSO SKB must be CHECKSUM_PARTIAL. However some buggy
979 * peers can fail to set NETRXF_csum_blank when sending a GSO
980 * frame. In this case force the SKB to CHECKSUM_PARTIAL and
981 * recalculate the partial checksum.
982 */
983 if (skb->ip_summed != CHECKSUM_PARTIAL && skb_is_gso(skb)) {
984 struct netfront_info *np = netdev_priv(dev);
985 atomic_inc(&np->rx_gso_checksum_fixup);
986 skb->ip_summed = CHECKSUM_PARTIAL;
987 recalculate_partial_csum = true;
988 }
989
990 /* A non-CHECKSUM_PARTIAL SKB does not require setup. */
991 if (skb->ip_summed != CHECKSUM_PARTIAL)
992 return 0;
993
994 return skb_checksum_setup(skb, recalculate_partial_csum);
995 }
996
handle_incoming_queue(struct netfront_queue * queue,struct sk_buff_head * rxq)997 static int handle_incoming_queue(struct netfront_queue *queue,
998 struct sk_buff_head *rxq)
999 {
1000 struct netfront_stats *rx_stats = this_cpu_ptr(queue->info->rx_stats);
1001 int packets_dropped = 0;
1002 struct sk_buff *skb;
1003
1004 while ((skb = __skb_dequeue(rxq)) != NULL) {
1005 int pull_to = NETFRONT_SKB_CB(skb)->pull_to;
1006
1007 if (pull_to > skb_headlen(skb))
1008 __pskb_pull_tail(skb, pull_to - skb_headlen(skb));
1009
1010 /* Ethernet work: Delayed to here as it peeks the header. */
1011 skb->protocol = eth_type_trans(skb, queue->info->netdev);
1012 skb_reset_network_header(skb);
1013
1014 if (checksum_setup(queue->info->netdev, skb)) {
1015 kfree_skb(skb);
1016 packets_dropped++;
1017 queue->info->netdev->stats.rx_errors++;
1018 continue;
1019 }
1020
1021 u64_stats_update_begin(&rx_stats->syncp);
1022 rx_stats->packets++;
1023 rx_stats->bytes += skb->len;
1024 u64_stats_update_end(&rx_stats->syncp);
1025
1026 /* Pass it up. */
1027 napi_gro_receive(&queue->napi, skb);
1028 }
1029
1030 return packets_dropped;
1031 }
1032
xennet_poll(struct napi_struct * napi,int budget)1033 static int xennet_poll(struct napi_struct *napi, int budget)
1034 {
1035 struct netfront_queue *queue = container_of(napi, struct netfront_queue, napi);
1036 struct net_device *dev = queue->info->netdev;
1037 struct sk_buff *skb;
1038 struct netfront_rx_info rinfo;
1039 struct xen_netif_rx_response *rx = &rinfo.rx;
1040 struct xen_netif_extra_info *extras = rinfo.extras;
1041 RING_IDX i, rp;
1042 int work_done;
1043 struct sk_buff_head rxq;
1044 struct sk_buff_head errq;
1045 struct sk_buff_head tmpq;
1046 int err;
1047
1048 spin_lock(&queue->rx_lock);
1049
1050 skb_queue_head_init(&rxq);
1051 skb_queue_head_init(&errq);
1052 skb_queue_head_init(&tmpq);
1053
1054 rp = queue->rx.sring->rsp_prod;
1055 if (RING_RESPONSE_PROD_OVERFLOW(&queue->rx, rp)) {
1056 dev_alert(&dev->dev, "Illegal number of responses %u\n",
1057 rp - queue->rx.rsp_cons);
1058 queue->info->broken = true;
1059 spin_unlock(&queue->rx_lock);
1060 return 0;
1061 }
1062 rmb(); /* Ensure we see queued responses up to 'rp'. */
1063
1064 i = queue->rx.rsp_cons;
1065 work_done = 0;
1066 while ((i != rp) && (work_done < budget)) {
1067 RING_COPY_RESPONSE(&queue->rx, i, rx);
1068 memset(extras, 0, sizeof(rinfo.extras));
1069
1070 err = xennet_get_responses(queue, &rinfo, rp, &tmpq);
1071
1072 if (unlikely(err)) {
1073 err:
1074 while ((skb = __skb_dequeue(&tmpq)))
1075 __skb_queue_tail(&errq, skb);
1076 dev->stats.rx_errors++;
1077 i = queue->rx.rsp_cons;
1078 continue;
1079 }
1080
1081 skb = __skb_dequeue(&tmpq);
1082
1083 if (extras[XEN_NETIF_EXTRA_TYPE_GSO - 1].type) {
1084 struct xen_netif_extra_info *gso;
1085 gso = &extras[XEN_NETIF_EXTRA_TYPE_GSO - 1];
1086
1087 if (unlikely(xennet_set_skb_gso(skb, gso))) {
1088 __skb_queue_head(&tmpq, skb);
1089 xennet_set_rx_rsp_cons(queue,
1090 queue->rx.rsp_cons +
1091 skb_queue_len(&tmpq));
1092 goto err;
1093 }
1094 }
1095
1096 NETFRONT_SKB_CB(skb)->pull_to = rx->status;
1097 if (NETFRONT_SKB_CB(skb)->pull_to > RX_COPY_THRESHOLD)
1098 NETFRONT_SKB_CB(skb)->pull_to = RX_COPY_THRESHOLD;
1099
1100 skb_shinfo(skb)->frags[0].page_offset = rx->offset;
1101 skb_frag_size_set(&skb_shinfo(skb)->frags[0], rx->status);
1102 skb->data_len = rx->status;
1103 skb->len += rx->status;
1104
1105 if (unlikely(xennet_fill_frags(queue, skb, &tmpq)))
1106 goto err;
1107
1108 if (rx->flags & XEN_NETRXF_csum_blank)
1109 skb->ip_summed = CHECKSUM_PARTIAL;
1110 else if (rx->flags & XEN_NETRXF_data_validated)
1111 skb->ip_summed = CHECKSUM_UNNECESSARY;
1112
1113 __skb_queue_tail(&rxq, skb);
1114
1115 i = queue->rx.rsp_cons + 1;
1116 xennet_set_rx_rsp_cons(queue, i);
1117 work_done++;
1118 }
1119
1120 __skb_queue_purge(&errq);
1121
1122 work_done -= handle_incoming_queue(queue, &rxq);
1123
1124 xennet_alloc_rx_buffers(queue);
1125
1126 if (work_done < budget) {
1127 int more_to_do = 0;
1128
1129 napi_complete(napi);
1130
1131 RING_FINAL_CHECK_FOR_RESPONSES(&queue->rx, more_to_do);
1132 if (more_to_do)
1133 napi_schedule(napi);
1134 }
1135
1136 spin_unlock(&queue->rx_lock);
1137
1138 return work_done;
1139 }
1140
xennet_change_mtu(struct net_device * dev,int mtu)1141 static int xennet_change_mtu(struct net_device *dev, int mtu)
1142 {
1143 int max = xennet_can_sg(dev) ? XEN_NETIF_MAX_TX_SIZE : ETH_DATA_LEN;
1144
1145 if (mtu > max)
1146 return -EINVAL;
1147 dev->mtu = mtu;
1148 return 0;
1149 }
1150
xennet_get_stats64(struct net_device * dev,struct rtnl_link_stats64 * tot)1151 static struct rtnl_link_stats64 *xennet_get_stats64(struct net_device *dev,
1152 struct rtnl_link_stats64 *tot)
1153 {
1154 struct netfront_info *np = netdev_priv(dev);
1155 int cpu;
1156
1157 for_each_possible_cpu(cpu) {
1158 struct netfront_stats *rx_stats = per_cpu_ptr(np->rx_stats, cpu);
1159 struct netfront_stats *tx_stats = per_cpu_ptr(np->tx_stats, cpu);
1160 u64 rx_packets, rx_bytes, tx_packets, tx_bytes;
1161 unsigned int start;
1162
1163 do {
1164 start = u64_stats_fetch_begin_irq(&tx_stats->syncp);
1165 tx_packets = tx_stats->packets;
1166 tx_bytes = tx_stats->bytes;
1167 } while (u64_stats_fetch_retry_irq(&tx_stats->syncp, start));
1168
1169 do {
1170 start = u64_stats_fetch_begin_irq(&rx_stats->syncp);
1171 rx_packets = rx_stats->packets;
1172 rx_bytes = rx_stats->bytes;
1173 } while (u64_stats_fetch_retry_irq(&rx_stats->syncp, start));
1174
1175 tot->rx_packets += rx_packets;
1176 tot->tx_packets += tx_packets;
1177 tot->rx_bytes += rx_bytes;
1178 tot->tx_bytes += tx_bytes;
1179 }
1180
1181 tot->rx_errors = dev->stats.rx_errors;
1182 tot->tx_dropped = dev->stats.tx_dropped;
1183
1184 return tot;
1185 }
1186
xennet_release_tx_bufs(struct netfront_queue * queue)1187 static void xennet_release_tx_bufs(struct netfront_queue *queue)
1188 {
1189 struct sk_buff *skb;
1190 int i;
1191
1192 for (i = 0; i < NET_TX_RING_SIZE; i++) {
1193 /* Skip over entries which are actually freelist references */
1194 if (!queue->tx_skbs[i])
1195 continue;
1196
1197 skb = queue->tx_skbs[i];
1198 queue->tx_skbs[i] = NULL;
1199 get_page(queue->grant_tx_page[i]);
1200 gnttab_end_foreign_access(queue->grant_tx_ref[i],
1201 GNTMAP_readonly,
1202 (unsigned long)page_address(queue->grant_tx_page[i]));
1203 queue->grant_tx_page[i] = NULL;
1204 queue->grant_tx_ref[i] = GRANT_INVALID_REF;
1205 add_id_to_list(&queue->tx_skb_freelist, queue->tx_link, i);
1206 dev_kfree_skb_irq(skb);
1207 }
1208 }
1209
xennet_release_rx_bufs(struct netfront_queue * queue)1210 static void xennet_release_rx_bufs(struct netfront_queue *queue)
1211 {
1212 int id, ref;
1213
1214 spin_lock_bh(&queue->rx_lock);
1215
1216 for (id = 0; id < NET_RX_RING_SIZE; id++) {
1217 struct sk_buff *skb;
1218 struct page *page;
1219
1220 skb = queue->rx_skbs[id];
1221 if (!skb)
1222 continue;
1223
1224 ref = queue->grant_rx_ref[id];
1225 if (ref == GRANT_INVALID_REF)
1226 continue;
1227
1228 page = skb_frag_page(&skb_shinfo(skb)->frags[0]);
1229
1230 /* gnttab_end_foreign_access() needs a page ref until
1231 * foreign access is ended (which may be deferred).
1232 */
1233 get_page(page);
1234 gnttab_end_foreign_access(ref, 0,
1235 (unsigned long)page_address(page));
1236 queue->grant_rx_ref[id] = GRANT_INVALID_REF;
1237
1238 kfree_skb(skb);
1239 }
1240
1241 spin_unlock_bh(&queue->rx_lock);
1242 }
1243
xennet_fix_features(struct net_device * dev,netdev_features_t features)1244 static netdev_features_t xennet_fix_features(struct net_device *dev,
1245 netdev_features_t features)
1246 {
1247 struct netfront_info *np = netdev_priv(dev);
1248 int val;
1249
1250 if (features & NETIF_F_SG) {
1251 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend, "feature-sg",
1252 "%d", &val) < 0)
1253 val = 0;
1254
1255 if (!val)
1256 features &= ~NETIF_F_SG;
1257 }
1258
1259 if (features & NETIF_F_IPV6_CSUM) {
1260 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend,
1261 "feature-ipv6-csum-offload", "%d", &val) < 0)
1262 val = 0;
1263
1264 if (!val)
1265 features &= ~NETIF_F_IPV6_CSUM;
1266 }
1267
1268 if (features & NETIF_F_TSO) {
1269 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend,
1270 "feature-gso-tcpv4", "%d", &val) < 0)
1271 val = 0;
1272
1273 if (!val)
1274 features &= ~NETIF_F_TSO;
1275 }
1276
1277 if (features & NETIF_F_TSO6) {
1278 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend,
1279 "feature-gso-tcpv6", "%d", &val) < 0)
1280 val = 0;
1281
1282 if (!val)
1283 features &= ~NETIF_F_TSO6;
1284 }
1285
1286 return features;
1287 }
1288
xennet_set_features(struct net_device * dev,netdev_features_t features)1289 static int xennet_set_features(struct net_device *dev,
1290 netdev_features_t features)
1291 {
1292 if (!(features & NETIF_F_SG) && dev->mtu > ETH_DATA_LEN) {
1293 netdev_info(dev, "Reducing MTU because no SG offload");
1294 dev->mtu = ETH_DATA_LEN;
1295 }
1296
1297 return 0;
1298 }
1299
xennet_handle_tx(struct netfront_queue * queue,unsigned int * eoi)1300 static bool xennet_handle_tx(struct netfront_queue *queue, unsigned int *eoi)
1301 {
1302 unsigned long flags;
1303
1304 if (unlikely(queue->info->broken))
1305 return false;
1306
1307 spin_lock_irqsave(&queue->tx_lock, flags);
1308 if (xennet_tx_buf_gc(queue))
1309 *eoi = 0;
1310 spin_unlock_irqrestore(&queue->tx_lock, flags);
1311
1312 return true;
1313 }
1314
xennet_tx_interrupt(int irq,void * dev_id)1315 static irqreturn_t xennet_tx_interrupt(int irq, void *dev_id)
1316 {
1317 unsigned int eoiflag = XEN_EOI_FLAG_SPURIOUS;
1318
1319 if (likely(xennet_handle_tx(dev_id, &eoiflag)))
1320 xen_irq_lateeoi(irq, eoiflag);
1321
1322 return IRQ_HANDLED;
1323 }
1324
xennet_handle_rx(struct netfront_queue * queue,unsigned int * eoi)1325 static bool xennet_handle_rx(struct netfront_queue *queue, unsigned int *eoi)
1326 {
1327 unsigned int work_queued;
1328 unsigned long flags;
1329
1330 if (unlikely(queue->info->broken))
1331 return false;
1332
1333 spin_lock_irqsave(&queue->rx_cons_lock, flags);
1334 work_queued = RING_HAS_UNCONSUMED_RESPONSES(&queue->rx);
1335 if (work_queued > queue->rx_rsp_unconsumed) {
1336 queue->rx_rsp_unconsumed = work_queued;
1337 *eoi = 0;
1338 } else if (unlikely(work_queued < queue->rx_rsp_unconsumed)) {
1339 const struct device *dev = &queue->info->netdev->dev;
1340
1341 spin_unlock_irqrestore(&queue->rx_cons_lock, flags);
1342 dev_alert(dev, "RX producer index going backwards\n");
1343 dev_alert(dev, "Disabled for further use\n");
1344 queue->info->broken = true;
1345 return false;
1346 }
1347 spin_unlock_irqrestore(&queue->rx_cons_lock, flags);
1348
1349 if (likely(netif_carrier_ok(queue->info->netdev) && work_queued))
1350 napi_schedule(&queue->napi);
1351
1352 return true;
1353 }
1354
xennet_rx_interrupt(int irq,void * dev_id)1355 static irqreturn_t xennet_rx_interrupt(int irq, void *dev_id)
1356 {
1357 unsigned int eoiflag = XEN_EOI_FLAG_SPURIOUS;
1358
1359 if (likely(xennet_handle_rx(dev_id, &eoiflag)))
1360 xen_irq_lateeoi(irq, eoiflag);
1361
1362 return IRQ_HANDLED;
1363 }
1364
xennet_interrupt(int irq,void * dev_id)1365 static irqreturn_t xennet_interrupt(int irq, void *dev_id)
1366 {
1367 unsigned int eoiflag = XEN_EOI_FLAG_SPURIOUS;
1368
1369 if (xennet_handle_tx(dev_id, &eoiflag) &&
1370 xennet_handle_rx(dev_id, &eoiflag))
1371 xen_irq_lateeoi(irq, eoiflag);
1372
1373 return IRQ_HANDLED;
1374 }
1375
1376 #ifdef CONFIG_NET_POLL_CONTROLLER
xennet_poll_controller(struct net_device * dev)1377 static void xennet_poll_controller(struct net_device *dev)
1378 {
1379 /* Poll each queue */
1380 struct netfront_info *info = netdev_priv(dev);
1381 unsigned int num_queues = dev->real_num_tx_queues;
1382 unsigned int i;
1383
1384 if (info->broken)
1385 return;
1386
1387 for (i = 0; i < num_queues; ++i)
1388 xennet_interrupt(0, &info->queues[i]);
1389 }
1390 #endif
1391
1392 static const struct net_device_ops xennet_netdev_ops = {
1393 .ndo_open = xennet_open,
1394 .ndo_stop = xennet_close,
1395 .ndo_start_xmit = xennet_start_xmit,
1396 .ndo_change_mtu = xennet_change_mtu,
1397 .ndo_get_stats64 = xennet_get_stats64,
1398 .ndo_set_mac_address = eth_mac_addr,
1399 .ndo_validate_addr = eth_validate_addr,
1400 .ndo_fix_features = xennet_fix_features,
1401 .ndo_set_features = xennet_set_features,
1402 .ndo_select_queue = xennet_select_queue,
1403 #ifdef CONFIG_NET_POLL_CONTROLLER
1404 .ndo_poll_controller = xennet_poll_controller,
1405 #endif
1406 };
1407
xennet_free_netdev(struct net_device * netdev)1408 static void xennet_free_netdev(struct net_device *netdev)
1409 {
1410 struct netfront_info *np = netdev_priv(netdev);
1411
1412 free_percpu(np->rx_stats);
1413 free_percpu(np->tx_stats);
1414 free_netdev(netdev);
1415 }
1416
xennet_create_dev(struct xenbus_device * dev)1417 static struct net_device *xennet_create_dev(struct xenbus_device *dev)
1418 {
1419 int err;
1420 struct net_device *netdev;
1421 struct netfront_info *np;
1422
1423 netdev = alloc_etherdev_mq(sizeof(struct netfront_info), xennet_max_queues);
1424 if (!netdev)
1425 return ERR_PTR(-ENOMEM);
1426
1427 np = netdev_priv(netdev);
1428 np->xbdev = dev;
1429
1430 np->queues = NULL;
1431
1432 err = -ENOMEM;
1433 np->rx_stats = netdev_alloc_pcpu_stats(struct netfront_stats);
1434 if (np->rx_stats == NULL)
1435 goto exit;
1436 np->tx_stats = netdev_alloc_pcpu_stats(struct netfront_stats);
1437 if (np->tx_stats == NULL)
1438 goto exit;
1439
1440 netdev->netdev_ops = &xennet_netdev_ops;
1441
1442 netdev->features = NETIF_F_IP_CSUM | NETIF_F_RXCSUM |
1443 NETIF_F_GSO_ROBUST;
1444 netdev->hw_features = NETIF_F_SG |
1445 NETIF_F_IPV6_CSUM |
1446 NETIF_F_TSO | NETIF_F_TSO6;
1447
1448 /*
1449 * Assume that all hw features are available for now. This set
1450 * will be adjusted by the call to netdev_update_features() in
1451 * xennet_connect() which is the earliest point where we can
1452 * negotiate with the backend regarding supported features.
1453 */
1454 netdev->features |= netdev->hw_features;
1455
1456 netdev->ethtool_ops = &xennet_ethtool_ops;
1457 SET_NETDEV_DEV(netdev, &dev->dev);
1458
1459 np->netdev = netdev;
1460
1461 netif_carrier_off(netdev);
1462
1463 do {
1464 xenbus_switch_state(dev, XenbusStateInitialising);
1465 err = wait_event_timeout(module_wq,
1466 xenbus_read_driver_state(dev->otherend) !=
1467 XenbusStateClosed &&
1468 xenbus_read_driver_state(dev->otherend) !=
1469 XenbusStateUnknown, XENNET_TIMEOUT);
1470 } while (!err);
1471
1472 return netdev;
1473
1474 exit:
1475 xennet_free_netdev(netdev);
1476 return ERR_PTR(err);
1477 }
1478
1479 /**
1480 * Entry point to this code when a new device is created. Allocate the basic
1481 * structures and the ring buffers for communication with the backend, and
1482 * inform the backend of the appropriate details for those.
1483 */
netfront_probe(struct xenbus_device * dev,const struct xenbus_device_id * id)1484 static int netfront_probe(struct xenbus_device *dev,
1485 const struct xenbus_device_id *id)
1486 {
1487 int err;
1488 struct net_device *netdev;
1489 struct netfront_info *info;
1490
1491 netdev = xennet_create_dev(dev);
1492 if (IS_ERR(netdev)) {
1493 err = PTR_ERR(netdev);
1494 xenbus_dev_fatal(dev, err, "creating netdev");
1495 return err;
1496 }
1497
1498 info = netdev_priv(netdev);
1499 dev_set_drvdata(&dev->dev, info);
1500 #ifdef CONFIG_SYSFS
1501 info->netdev->sysfs_groups[0] = &xennet_dev_group;
1502 #endif
1503
1504 return 0;
1505 }
1506
xennet_end_access(int ref,void * page)1507 static void xennet_end_access(int ref, void *page)
1508 {
1509 /* This frees the page as a side-effect */
1510 if (ref != GRANT_INVALID_REF)
1511 gnttab_end_foreign_access(ref, 0, (unsigned long)page);
1512 }
1513
xennet_disconnect_backend(struct netfront_info * info)1514 static void xennet_disconnect_backend(struct netfront_info *info)
1515 {
1516 unsigned int i = 0;
1517 unsigned int num_queues = info->netdev->real_num_tx_queues;
1518
1519 netif_carrier_off(info->netdev);
1520
1521 for (i = 0; i < num_queues && info->queues; ++i) {
1522 struct netfront_queue *queue = &info->queues[i];
1523
1524 del_timer_sync(&queue->rx_refill_timer);
1525
1526 if (queue->tx_irq && (queue->tx_irq == queue->rx_irq))
1527 unbind_from_irqhandler(queue->tx_irq, queue);
1528 if (queue->tx_irq && (queue->tx_irq != queue->rx_irq)) {
1529 unbind_from_irqhandler(queue->tx_irq, queue);
1530 unbind_from_irqhandler(queue->rx_irq, queue);
1531 }
1532 queue->tx_evtchn = queue->rx_evtchn = 0;
1533 queue->tx_irq = queue->rx_irq = 0;
1534
1535 if (netif_running(info->netdev))
1536 napi_synchronize(&queue->napi);
1537
1538 xennet_release_tx_bufs(queue);
1539 xennet_release_rx_bufs(queue);
1540 gnttab_free_grant_references(queue->gref_tx_head);
1541 gnttab_free_grant_references(queue->gref_rx_head);
1542
1543 /* End access and free the pages */
1544 xennet_end_access(queue->tx_ring_ref, queue->tx.sring);
1545 xennet_end_access(queue->rx_ring_ref, queue->rx.sring);
1546
1547 queue->tx_ring_ref = GRANT_INVALID_REF;
1548 queue->rx_ring_ref = GRANT_INVALID_REF;
1549 queue->tx.sring = NULL;
1550 queue->rx.sring = NULL;
1551 }
1552 }
1553
1554 /**
1555 * We are reconnecting to the backend, due to a suspend/resume, or a backend
1556 * driver restart. We tear down our netif structure and recreate it, but
1557 * leave the device-layer structures intact so that this is transparent to the
1558 * rest of the kernel.
1559 */
netfront_resume(struct xenbus_device * dev)1560 static int netfront_resume(struct xenbus_device *dev)
1561 {
1562 struct netfront_info *info = dev_get_drvdata(&dev->dev);
1563
1564 dev_dbg(&dev->dev, "%s\n", dev->nodename);
1565
1566 netif_tx_lock_bh(info->netdev);
1567 netif_device_detach(info->netdev);
1568 netif_tx_unlock_bh(info->netdev);
1569
1570 xennet_disconnect_backend(info);
1571 return 0;
1572 }
1573
xen_net_read_mac(struct xenbus_device * dev,u8 mac[])1574 static int xen_net_read_mac(struct xenbus_device *dev, u8 mac[])
1575 {
1576 char *s, *e, *macstr;
1577 int i;
1578
1579 macstr = s = xenbus_read(XBT_NIL, dev->nodename, "mac", NULL);
1580 if (IS_ERR(macstr))
1581 return PTR_ERR(macstr);
1582
1583 for (i = 0; i < ETH_ALEN; i++) {
1584 mac[i] = simple_strtoul(s, &e, 16);
1585 if ((s == e) || (*e != ((i == ETH_ALEN-1) ? '\0' : ':'))) {
1586 kfree(macstr);
1587 return -ENOENT;
1588 }
1589 s = e+1;
1590 }
1591
1592 kfree(macstr);
1593 return 0;
1594 }
1595
setup_netfront_single(struct netfront_queue * queue)1596 static int setup_netfront_single(struct netfront_queue *queue)
1597 {
1598 int err;
1599
1600 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->tx_evtchn);
1601 if (err < 0)
1602 goto fail;
1603
1604 err = bind_evtchn_to_irqhandler_lateeoi(queue->tx_evtchn,
1605 xennet_interrupt, 0,
1606 queue->info->netdev->name,
1607 queue);
1608 if (err < 0)
1609 goto bind_fail;
1610 queue->rx_evtchn = queue->tx_evtchn;
1611 queue->rx_irq = queue->tx_irq = err;
1612
1613 return 0;
1614
1615 bind_fail:
1616 xenbus_free_evtchn(queue->info->xbdev, queue->tx_evtchn);
1617 queue->tx_evtchn = 0;
1618 fail:
1619 return err;
1620 }
1621
setup_netfront_split(struct netfront_queue * queue)1622 static int setup_netfront_split(struct netfront_queue *queue)
1623 {
1624 int err;
1625
1626 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->tx_evtchn);
1627 if (err < 0)
1628 goto fail;
1629 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->rx_evtchn);
1630 if (err < 0)
1631 goto alloc_rx_evtchn_fail;
1632
1633 snprintf(queue->tx_irq_name, sizeof(queue->tx_irq_name),
1634 "%s-tx", queue->name);
1635 err = bind_evtchn_to_irqhandler_lateeoi(queue->tx_evtchn,
1636 xennet_tx_interrupt, 0,
1637 queue->tx_irq_name, queue);
1638 if (err < 0)
1639 goto bind_tx_fail;
1640 queue->tx_irq = err;
1641
1642 snprintf(queue->rx_irq_name, sizeof(queue->rx_irq_name),
1643 "%s-rx", queue->name);
1644 err = bind_evtchn_to_irqhandler_lateeoi(queue->rx_evtchn,
1645 xennet_rx_interrupt, 0,
1646 queue->rx_irq_name, queue);
1647 if (err < 0)
1648 goto bind_rx_fail;
1649 queue->rx_irq = err;
1650
1651 return 0;
1652
1653 bind_rx_fail:
1654 unbind_from_irqhandler(queue->tx_irq, queue);
1655 queue->tx_irq = 0;
1656 bind_tx_fail:
1657 xenbus_free_evtchn(queue->info->xbdev, queue->rx_evtchn);
1658 queue->rx_evtchn = 0;
1659 alloc_rx_evtchn_fail:
1660 xenbus_free_evtchn(queue->info->xbdev, queue->tx_evtchn);
1661 queue->tx_evtchn = 0;
1662 fail:
1663 return err;
1664 }
1665
setup_netfront(struct xenbus_device * dev,struct netfront_queue * queue,unsigned int feature_split_evtchn)1666 static int setup_netfront(struct xenbus_device *dev,
1667 struct netfront_queue *queue, unsigned int feature_split_evtchn)
1668 {
1669 struct xen_netif_tx_sring *txs;
1670 struct xen_netif_rx_sring *rxs;
1671 grant_ref_t gref;
1672 int err;
1673
1674 queue->tx_ring_ref = GRANT_INVALID_REF;
1675 queue->rx_ring_ref = GRANT_INVALID_REF;
1676 queue->rx.sring = NULL;
1677 queue->tx.sring = NULL;
1678
1679 txs = (struct xen_netif_tx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH);
1680 if (!txs) {
1681 err = -ENOMEM;
1682 xenbus_dev_fatal(dev, err, "allocating tx ring page");
1683 goto fail;
1684 }
1685 SHARED_RING_INIT(txs);
1686 FRONT_RING_INIT(&queue->tx, txs, XEN_PAGE_SIZE);
1687
1688 err = xenbus_grant_ring(dev, txs, 1, &gref);
1689 if (err < 0)
1690 goto grant_tx_ring_fail;
1691 queue->tx_ring_ref = gref;
1692
1693 rxs = (struct xen_netif_rx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH);
1694 if (!rxs) {
1695 err = -ENOMEM;
1696 xenbus_dev_fatal(dev, err, "allocating rx ring page");
1697 goto alloc_rx_ring_fail;
1698 }
1699 SHARED_RING_INIT(rxs);
1700 FRONT_RING_INIT(&queue->rx, rxs, XEN_PAGE_SIZE);
1701
1702 err = xenbus_grant_ring(dev, rxs, 1, &gref);
1703 if (err < 0)
1704 goto grant_rx_ring_fail;
1705 queue->rx_ring_ref = gref;
1706
1707 if (feature_split_evtchn)
1708 err = setup_netfront_split(queue);
1709 /* setup single event channel if
1710 * a) feature-split-event-channels == 0
1711 * b) feature-split-event-channels == 1 but failed to setup
1712 */
1713 if (!feature_split_evtchn || (feature_split_evtchn && err))
1714 err = setup_netfront_single(queue);
1715
1716 if (err)
1717 goto alloc_evtchn_fail;
1718
1719 return 0;
1720
1721 /* If we fail to setup netfront, it is safe to just revoke access to
1722 * granted pages because backend is not accessing it at this point.
1723 */
1724 alloc_evtchn_fail:
1725 gnttab_end_foreign_access_ref(queue->rx_ring_ref, 0);
1726 grant_rx_ring_fail:
1727 free_page((unsigned long)rxs);
1728 alloc_rx_ring_fail:
1729 gnttab_end_foreign_access_ref(queue->tx_ring_ref, 0);
1730 grant_tx_ring_fail:
1731 free_page((unsigned long)txs);
1732 fail:
1733 return err;
1734 }
1735
1736 /* Queue-specific initialisation
1737 * This used to be done in xennet_create_dev() but must now
1738 * be run per-queue.
1739 */
xennet_init_queue(struct netfront_queue * queue)1740 static int xennet_init_queue(struct netfront_queue *queue)
1741 {
1742 unsigned short i;
1743 int err = 0;
1744 char *devid;
1745
1746 spin_lock_init(&queue->tx_lock);
1747 spin_lock_init(&queue->rx_lock);
1748 spin_lock_init(&queue->rx_cons_lock);
1749
1750 setup_timer(&queue->rx_refill_timer, rx_refill_timeout,
1751 (unsigned long)queue);
1752
1753 devid = strrchr(queue->info->xbdev->nodename, '/') + 1;
1754 snprintf(queue->name, sizeof(queue->name), "vif%s-q%u",
1755 devid, queue->id);
1756
1757 /* Initialise tx_skb_freelist as a free chain containing every entry. */
1758 queue->tx_skb_freelist = 0;
1759 queue->tx_pend_queue = TX_LINK_NONE;
1760 for (i = 0; i < NET_TX_RING_SIZE; i++) {
1761 queue->tx_link[i] = i + 1;
1762 queue->grant_tx_ref[i] = GRANT_INVALID_REF;
1763 queue->grant_tx_page[i] = NULL;
1764 }
1765 queue->tx_link[NET_TX_RING_SIZE - 1] = TX_LINK_NONE;
1766
1767 /* Clear out rx_skbs */
1768 for (i = 0; i < NET_RX_RING_SIZE; i++) {
1769 queue->rx_skbs[i] = NULL;
1770 queue->grant_rx_ref[i] = GRANT_INVALID_REF;
1771 }
1772
1773 /* A grant for every tx ring slot */
1774 if (gnttab_alloc_grant_references(NET_TX_RING_SIZE,
1775 &queue->gref_tx_head) < 0) {
1776 pr_alert("can't alloc tx grant refs\n");
1777 err = -ENOMEM;
1778 goto exit;
1779 }
1780
1781 /* A grant for every rx ring slot */
1782 if (gnttab_alloc_grant_references(NET_RX_RING_SIZE,
1783 &queue->gref_rx_head) < 0) {
1784 pr_alert("can't alloc rx grant refs\n");
1785 err = -ENOMEM;
1786 goto exit_free_tx;
1787 }
1788
1789 return 0;
1790
1791 exit_free_tx:
1792 gnttab_free_grant_references(queue->gref_tx_head);
1793 exit:
1794 return err;
1795 }
1796
write_queue_xenstore_keys(struct netfront_queue * queue,struct xenbus_transaction * xbt,int write_hierarchical)1797 static int write_queue_xenstore_keys(struct netfront_queue *queue,
1798 struct xenbus_transaction *xbt, int write_hierarchical)
1799 {
1800 /* Write the queue-specific keys into XenStore in the traditional
1801 * way for a single queue, or in a queue subkeys for multiple
1802 * queues.
1803 */
1804 struct xenbus_device *dev = queue->info->xbdev;
1805 int err;
1806 const char *message;
1807 char *path;
1808 size_t pathsize;
1809
1810 /* Choose the correct place to write the keys */
1811 if (write_hierarchical) {
1812 pathsize = strlen(dev->nodename) + 10;
1813 path = kzalloc(pathsize, GFP_KERNEL);
1814 if (!path) {
1815 err = -ENOMEM;
1816 message = "out of memory while writing ring references";
1817 goto error;
1818 }
1819 snprintf(path, pathsize, "%s/queue-%u",
1820 dev->nodename, queue->id);
1821 } else {
1822 path = (char *)dev->nodename;
1823 }
1824
1825 /* Write ring references */
1826 err = xenbus_printf(*xbt, path, "tx-ring-ref", "%u",
1827 queue->tx_ring_ref);
1828 if (err) {
1829 message = "writing tx-ring-ref";
1830 goto error;
1831 }
1832
1833 err = xenbus_printf(*xbt, path, "rx-ring-ref", "%u",
1834 queue->rx_ring_ref);
1835 if (err) {
1836 message = "writing rx-ring-ref";
1837 goto error;
1838 }
1839
1840 /* Write event channels; taking into account both shared
1841 * and split event channel scenarios.
1842 */
1843 if (queue->tx_evtchn == queue->rx_evtchn) {
1844 /* Shared event channel */
1845 err = xenbus_printf(*xbt, path,
1846 "event-channel", "%u", queue->tx_evtchn);
1847 if (err) {
1848 message = "writing event-channel";
1849 goto error;
1850 }
1851 } else {
1852 /* Split event channels */
1853 err = xenbus_printf(*xbt, path,
1854 "event-channel-tx", "%u", queue->tx_evtchn);
1855 if (err) {
1856 message = "writing event-channel-tx";
1857 goto error;
1858 }
1859
1860 err = xenbus_printf(*xbt, path,
1861 "event-channel-rx", "%u", queue->rx_evtchn);
1862 if (err) {
1863 message = "writing event-channel-rx";
1864 goto error;
1865 }
1866 }
1867
1868 if (write_hierarchical)
1869 kfree(path);
1870 return 0;
1871
1872 error:
1873 if (write_hierarchical)
1874 kfree(path);
1875 xenbus_dev_fatal(dev, err, "%s", message);
1876 return err;
1877 }
1878
xennet_destroy_queues(struct netfront_info * info)1879 static void xennet_destroy_queues(struct netfront_info *info)
1880 {
1881 unsigned int i;
1882
1883 for (i = 0; i < info->netdev->real_num_tx_queues; i++) {
1884 struct netfront_queue *queue = &info->queues[i];
1885
1886 if (netif_running(info->netdev))
1887 napi_disable(&queue->napi);
1888 netif_napi_del(&queue->napi);
1889 }
1890
1891 kfree(info->queues);
1892 info->queues = NULL;
1893 }
1894
xennet_create_queues(struct netfront_info * info,unsigned int * num_queues)1895 static int xennet_create_queues(struct netfront_info *info,
1896 unsigned int *num_queues)
1897 {
1898 unsigned int i;
1899 int ret;
1900
1901 info->queues = kcalloc(*num_queues, sizeof(struct netfront_queue),
1902 GFP_KERNEL);
1903 if (!info->queues)
1904 return -ENOMEM;
1905
1906 for (i = 0; i < *num_queues; i++) {
1907 struct netfront_queue *queue = &info->queues[i];
1908
1909 queue->id = i;
1910 queue->info = info;
1911
1912 ret = xennet_init_queue(queue);
1913 if (ret < 0) {
1914 dev_warn(&info->xbdev->dev,
1915 "only created %d queues\n", i);
1916 *num_queues = i;
1917 break;
1918 }
1919
1920 netif_napi_add(queue->info->netdev, &queue->napi,
1921 xennet_poll, 64);
1922 if (netif_running(info->netdev))
1923 napi_enable(&queue->napi);
1924 }
1925
1926 netif_set_real_num_tx_queues(info->netdev, *num_queues);
1927
1928 if (*num_queues == 0) {
1929 dev_err(&info->xbdev->dev, "no queues\n");
1930 return -EINVAL;
1931 }
1932 return 0;
1933 }
1934
1935 /* Common code used when first setting up, and when resuming. */
talk_to_netback(struct xenbus_device * dev,struct netfront_info * info)1936 static int talk_to_netback(struct xenbus_device *dev,
1937 struct netfront_info *info)
1938 {
1939 const char *message;
1940 struct xenbus_transaction xbt;
1941 int err;
1942 unsigned int feature_split_evtchn;
1943 unsigned int i = 0;
1944 unsigned int max_queues = 0;
1945 struct netfront_queue *queue = NULL;
1946 unsigned int num_queues = 1;
1947
1948 info->netdev->irq = 0;
1949
1950 /* Check if backend supports multiple queues */
1951 err = xenbus_scanf(XBT_NIL, info->xbdev->otherend,
1952 "multi-queue-max-queues", "%u", &max_queues);
1953 if (err < 0)
1954 max_queues = 1;
1955 num_queues = min(max_queues, xennet_max_queues);
1956
1957 /* Check feature-split-event-channels */
1958 err = xenbus_scanf(XBT_NIL, info->xbdev->otherend,
1959 "feature-split-event-channels", "%u",
1960 &feature_split_evtchn);
1961 if (err < 0)
1962 feature_split_evtchn = 0;
1963
1964 /* Read mac addr. */
1965 err = xen_net_read_mac(dev, info->netdev->dev_addr);
1966 if (err) {
1967 xenbus_dev_fatal(dev, err, "parsing %s/mac", dev->nodename);
1968 goto out_unlocked;
1969 }
1970
1971 rtnl_lock();
1972 if (info->queues)
1973 xennet_destroy_queues(info);
1974
1975 /* For the case of a reconnect reset the "broken" indicator. */
1976 info->broken = false;
1977
1978 err = xennet_create_queues(info, &num_queues);
1979 if (err < 0) {
1980 xenbus_dev_fatal(dev, err, "creating queues");
1981 kfree(info->queues);
1982 info->queues = NULL;
1983 goto out;
1984 }
1985 rtnl_unlock();
1986
1987 /* Create shared ring, alloc event channel -- for each queue */
1988 for (i = 0; i < num_queues; ++i) {
1989 queue = &info->queues[i];
1990 err = setup_netfront(dev, queue, feature_split_evtchn);
1991 if (err)
1992 goto destroy_ring;
1993 }
1994
1995 again:
1996 err = xenbus_transaction_start(&xbt);
1997 if (err) {
1998 xenbus_dev_fatal(dev, err, "starting transaction");
1999 goto destroy_ring;
2000 }
2001
2002 if (xenbus_exists(XBT_NIL,
2003 info->xbdev->otherend, "multi-queue-max-queues")) {
2004 /* Write the number of queues */
2005 err = xenbus_printf(xbt, dev->nodename,
2006 "multi-queue-num-queues", "%u", num_queues);
2007 if (err) {
2008 message = "writing multi-queue-num-queues";
2009 goto abort_transaction_no_dev_fatal;
2010 }
2011 }
2012
2013 if (num_queues == 1) {
2014 err = write_queue_xenstore_keys(&info->queues[0], &xbt, 0); /* flat */
2015 if (err)
2016 goto abort_transaction_no_dev_fatal;
2017 } else {
2018 /* Write the keys for each queue */
2019 for (i = 0; i < num_queues; ++i) {
2020 queue = &info->queues[i];
2021 err = write_queue_xenstore_keys(queue, &xbt, 1); /* hierarchical */
2022 if (err)
2023 goto abort_transaction_no_dev_fatal;
2024 }
2025 }
2026
2027 /* The remaining keys are not queue-specific */
2028 err = xenbus_printf(xbt, dev->nodename, "request-rx-copy", "%u",
2029 1);
2030 if (err) {
2031 message = "writing request-rx-copy";
2032 goto abort_transaction;
2033 }
2034
2035 err = xenbus_printf(xbt, dev->nodename, "feature-rx-notify", "%d", 1);
2036 if (err) {
2037 message = "writing feature-rx-notify";
2038 goto abort_transaction;
2039 }
2040
2041 err = xenbus_printf(xbt, dev->nodename, "feature-sg", "%d", 1);
2042 if (err) {
2043 message = "writing feature-sg";
2044 goto abort_transaction;
2045 }
2046
2047 err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv4", "%d", 1);
2048 if (err) {
2049 message = "writing feature-gso-tcpv4";
2050 goto abort_transaction;
2051 }
2052
2053 err = xenbus_write(xbt, dev->nodename, "feature-gso-tcpv6", "1");
2054 if (err) {
2055 message = "writing feature-gso-tcpv6";
2056 goto abort_transaction;
2057 }
2058
2059 err = xenbus_write(xbt, dev->nodename, "feature-ipv6-csum-offload",
2060 "1");
2061 if (err) {
2062 message = "writing feature-ipv6-csum-offload";
2063 goto abort_transaction;
2064 }
2065
2066 err = xenbus_transaction_end(xbt, 0);
2067 if (err) {
2068 if (err == -EAGAIN)
2069 goto again;
2070 xenbus_dev_fatal(dev, err, "completing transaction");
2071 goto destroy_ring;
2072 }
2073
2074 return 0;
2075
2076 abort_transaction:
2077 xenbus_dev_fatal(dev, err, "%s", message);
2078 abort_transaction_no_dev_fatal:
2079 xenbus_transaction_end(xbt, 1);
2080 destroy_ring:
2081 xennet_disconnect_backend(info);
2082 rtnl_lock();
2083 xennet_destroy_queues(info);
2084 out:
2085 rtnl_unlock();
2086 out_unlocked:
2087 device_unregister(&dev->dev);
2088 return err;
2089 }
2090
xennet_connect(struct net_device * dev)2091 static int xennet_connect(struct net_device *dev)
2092 {
2093 struct netfront_info *np = netdev_priv(dev);
2094 unsigned int num_queues = 0;
2095 int err;
2096 unsigned int feature_rx_copy;
2097 unsigned int j = 0;
2098 struct netfront_queue *queue = NULL;
2099
2100 err = xenbus_scanf(XBT_NIL, np->xbdev->otherend,
2101 "feature-rx-copy", "%u", &feature_rx_copy);
2102 if (err != 1)
2103 feature_rx_copy = 0;
2104
2105 if (!feature_rx_copy) {
2106 dev_info(&dev->dev,
2107 "backend does not support copying receive path\n");
2108 return -ENODEV;
2109 }
2110
2111 err = talk_to_netback(np->xbdev, np);
2112 if (err)
2113 return err;
2114
2115 /* talk_to_netback() sets the correct number of queues */
2116 num_queues = dev->real_num_tx_queues;
2117
2118 if (dev->reg_state == NETREG_UNINITIALIZED) {
2119 err = register_netdev(dev);
2120 if (err) {
2121 pr_warn("%s: register_netdev err=%d\n", __func__, err);
2122 device_unregister(&np->xbdev->dev);
2123 return err;
2124 }
2125 }
2126
2127 rtnl_lock();
2128 netdev_update_features(dev);
2129 rtnl_unlock();
2130
2131 /*
2132 * All public and private state should now be sane. Get
2133 * ready to start sending and receiving packets and give the driver
2134 * domain a kick because we've probably just requeued some
2135 * packets.
2136 */
2137 netif_tx_lock_bh(np->netdev);
2138 netif_device_attach(np->netdev);
2139 netif_tx_unlock_bh(np->netdev);
2140
2141 netif_carrier_on(np->netdev);
2142 for (j = 0; j < num_queues; ++j) {
2143 queue = &np->queues[j];
2144
2145 notify_remote_via_irq(queue->tx_irq);
2146 if (queue->tx_irq != queue->rx_irq)
2147 notify_remote_via_irq(queue->rx_irq);
2148
2149 spin_lock_irq(&queue->tx_lock);
2150 xennet_tx_buf_gc(queue);
2151 spin_unlock_irq(&queue->tx_lock);
2152
2153 spin_lock_bh(&queue->rx_lock);
2154 xennet_alloc_rx_buffers(queue);
2155 spin_unlock_bh(&queue->rx_lock);
2156 }
2157
2158 return 0;
2159 }
2160
2161 /**
2162 * Callback received when the backend's state changes.
2163 */
netback_changed(struct xenbus_device * dev,enum xenbus_state backend_state)2164 static void netback_changed(struct xenbus_device *dev,
2165 enum xenbus_state backend_state)
2166 {
2167 struct netfront_info *np = dev_get_drvdata(&dev->dev);
2168 struct net_device *netdev = np->netdev;
2169
2170 dev_dbg(&dev->dev, "%s\n", xenbus_strstate(backend_state));
2171
2172 wake_up_all(&module_wq);
2173
2174 switch (backend_state) {
2175 case XenbusStateInitialising:
2176 case XenbusStateInitialised:
2177 case XenbusStateReconfiguring:
2178 case XenbusStateReconfigured:
2179 case XenbusStateUnknown:
2180 break;
2181
2182 case XenbusStateInitWait:
2183 if (dev->state != XenbusStateInitialising)
2184 break;
2185 if (xennet_connect(netdev) != 0)
2186 break;
2187 xenbus_switch_state(dev, XenbusStateConnected);
2188 break;
2189
2190 case XenbusStateConnected:
2191 netdev_notify_peers(netdev);
2192 break;
2193
2194 case XenbusStateClosed:
2195 if (dev->state == XenbusStateClosed)
2196 break;
2197 /* Missed the backend's CLOSING state -- fallthrough */
2198 case XenbusStateClosing:
2199 xenbus_frontend_closed(dev);
2200 break;
2201 }
2202 }
2203
2204 static const struct xennet_stat {
2205 char name[ETH_GSTRING_LEN];
2206 u16 offset;
2207 } xennet_stats[] = {
2208 {
2209 "rx_gso_checksum_fixup",
2210 offsetof(struct netfront_info, rx_gso_checksum_fixup)
2211 },
2212 };
2213
xennet_get_sset_count(struct net_device * dev,int string_set)2214 static int xennet_get_sset_count(struct net_device *dev, int string_set)
2215 {
2216 switch (string_set) {
2217 case ETH_SS_STATS:
2218 return ARRAY_SIZE(xennet_stats);
2219 default:
2220 return -EINVAL;
2221 }
2222 }
2223
xennet_get_ethtool_stats(struct net_device * dev,struct ethtool_stats * stats,u64 * data)2224 static void xennet_get_ethtool_stats(struct net_device *dev,
2225 struct ethtool_stats *stats, u64 * data)
2226 {
2227 void *np = netdev_priv(dev);
2228 int i;
2229
2230 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++)
2231 data[i] = atomic_read((atomic_t *)(np + xennet_stats[i].offset));
2232 }
2233
xennet_get_strings(struct net_device * dev,u32 stringset,u8 * data)2234 static void xennet_get_strings(struct net_device *dev, u32 stringset, u8 * data)
2235 {
2236 int i;
2237
2238 switch (stringset) {
2239 case ETH_SS_STATS:
2240 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++)
2241 memcpy(data + i * ETH_GSTRING_LEN,
2242 xennet_stats[i].name, ETH_GSTRING_LEN);
2243 break;
2244 }
2245 }
2246
2247 static const struct ethtool_ops xennet_ethtool_ops =
2248 {
2249 .get_link = ethtool_op_get_link,
2250
2251 .get_sset_count = xennet_get_sset_count,
2252 .get_ethtool_stats = xennet_get_ethtool_stats,
2253 .get_strings = xennet_get_strings,
2254 };
2255
2256 #ifdef CONFIG_SYSFS
show_rxbuf(struct device * dev,struct device_attribute * attr,char * buf)2257 static ssize_t show_rxbuf(struct device *dev,
2258 struct device_attribute *attr, char *buf)
2259 {
2260 return sprintf(buf, "%lu\n", NET_RX_RING_SIZE);
2261 }
2262
store_rxbuf(struct device * dev,struct device_attribute * attr,const char * buf,size_t len)2263 static ssize_t store_rxbuf(struct device *dev,
2264 struct device_attribute *attr,
2265 const char *buf, size_t len)
2266 {
2267 char *endp;
2268 unsigned long target;
2269
2270 if (!capable(CAP_NET_ADMIN))
2271 return -EPERM;
2272
2273 target = simple_strtoul(buf, &endp, 0);
2274 if (endp == buf)
2275 return -EBADMSG;
2276
2277 /* rxbuf_min and rxbuf_max are no longer configurable. */
2278
2279 return len;
2280 }
2281
2282 static DEVICE_ATTR(rxbuf_min, S_IRUGO|S_IWUSR, show_rxbuf, store_rxbuf);
2283 static DEVICE_ATTR(rxbuf_max, S_IRUGO|S_IWUSR, show_rxbuf, store_rxbuf);
2284 static DEVICE_ATTR(rxbuf_cur, S_IRUGO, show_rxbuf, NULL);
2285
2286 static struct attribute *xennet_dev_attrs[] = {
2287 &dev_attr_rxbuf_min.attr,
2288 &dev_attr_rxbuf_max.attr,
2289 &dev_attr_rxbuf_cur.attr,
2290 NULL
2291 };
2292
2293 static const struct attribute_group xennet_dev_group = {
2294 .attrs = xennet_dev_attrs
2295 };
2296 #endif /* CONFIG_SYSFS */
2297
xennet_bus_close(struct xenbus_device * dev)2298 static void xennet_bus_close(struct xenbus_device *dev)
2299 {
2300 int ret;
2301
2302 if (xenbus_read_driver_state(dev->otherend) == XenbusStateClosed)
2303 return;
2304 do {
2305 xenbus_switch_state(dev, XenbusStateClosing);
2306 ret = wait_event_timeout(module_wq,
2307 xenbus_read_driver_state(dev->otherend) ==
2308 XenbusStateClosing ||
2309 xenbus_read_driver_state(dev->otherend) ==
2310 XenbusStateClosed ||
2311 xenbus_read_driver_state(dev->otherend) ==
2312 XenbusStateUnknown,
2313 XENNET_TIMEOUT);
2314 } while (!ret);
2315
2316 if (xenbus_read_driver_state(dev->otherend) == XenbusStateClosed)
2317 return;
2318
2319 do {
2320 xenbus_switch_state(dev, XenbusStateClosed);
2321 ret = wait_event_timeout(module_wq,
2322 xenbus_read_driver_state(dev->otherend) ==
2323 XenbusStateClosed ||
2324 xenbus_read_driver_state(dev->otherend) ==
2325 XenbusStateUnknown,
2326 XENNET_TIMEOUT);
2327 } while (!ret);
2328 }
2329
xennet_remove(struct xenbus_device * dev)2330 static int xennet_remove(struct xenbus_device *dev)
2331 {
2332 struct netfront_info *info = dev_get_drvdata(&dev->dev);
2333
2334 xennet_bus_close(dev);
2335 xennet_disconnect_backend(info);
2336
2337 if (info->netdev->reg_state == NETREG_REGISTERED)
2338 unregister_netdev(info->netdev);
2339
2340 if (info->queues) {
2341 rtnl_lock();
2342 xennet_destroy_queues(info);
2343 rtnl_unlock();
2344 }
2345 xennet_free_netdev(info->netdev);
2346
2347 return 0;
2348 }
2349
2350 static const struct xenbus_device_id netfront_ids[] = {
2351 { "vif" },
2352 { "" }
2353 };
2354
2355 static struct xenbus_driver netfront_driver = {
2356 .ids = netfront_ids,
2357 .probe = netfront_probe,
2358 .remove = xennet_remove,
2359 .resume = netfront_resume,
2360 .otherend_changed = netback_changed,
2361 };
2362
netif_init(void)2363 static int __init netif_init(void)
2364 {
2365 if (!xen_domain())
2366 return -ENODEV;
2367
2368 if (!xen_has_pv_nic_devices())
2369 return -ENODEV;
2370
2371 pr_info("Initialising Xen virtual ethernet driver\n");
2372
2373 /* Allow as many queues as there are CPUs if user has not
2374 * specified a value.
2375 */
2376 if (xennet_max_queues == 0)
2377 xennet_max_queues = num_online_cpus();
2378
2379 return xenbus_register_frontend(&netfront_driver);
2380 }
2381 module_init(netif_init);
2382
2383
netif_exit(void)2384 static void __exit netif_exit(void)
2385 {
2386 xenbus_unregister_driver(&netfront_driver);
2387 }
2388 module_exit(netif_exit);
2389
2390 MODULE_DESCRIPTION("Xen virtual network device frontend");
2391 MODULE_LICENSE("GPL");
2392 MODULE_ALIAS("xen:vif");
2393 MODULE_ALIAS("xennet");
2394