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1/*
2 * Virtual network driver for conversing with remote driver backends.
3 *
4 * Copyright (c) 2002-2005, K A Fraser
5 * Copyright (c) 2005, XenSource Ltd
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License version 2
9 * as published by the Free Software Foundation; or, when distributed
10 * separately from the Linux kernel or incorporated into other
11 * software packages, subject to the following license:
12 *
13 * Permission is hereby granted, free of charge, to any person obtaining a copy
14 * of this source file (the "Software"), to deal in the Software without
15 * restriction, including without limitation the rights to use, copy, modify,
16 * merge, publish, distribute, sublicense, and/or sell copies of the Software,
17 * and to permit persons to whom the Software is furnished to do so, subject to
18 * the following conditions:
19 *
20 * The above copyright notice and this permission notice shall be included in
21 * all copies or substantial portions of the Software.
22 *
23 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
24 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
25 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
26 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
27 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
28 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
29 * IN THE SOFTWARE.
30 */
31
32#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
33
34#include <linux/module.h>
35#include <linux/kernel.h>
36#include <linux/netdevice.h>
37#include <linux/etherdevice.h>
38#include <linux/skbuff.h>
39#include <linux/ethtool.h>
40#include <linux/if_ether.h>
41#include <net/tcp.h>
42#include <linux/udp.h>
43#include <linux/moduleparam.h>
44#include <linux/mm.h>
45#include <linux/slab.h>
46#include <net/ip.h>
47#include <linux/bpf.h>
48#include <net/page_pool/types.h>
49#include <linux/bpf_trace.h>
50
51#include <xen/xen.h>
52#include <xen/xenbus.h>
53#include <xen/events.h>
54#include <xen/page.h>
55#include <xen/platform_pci.h>
56#include <xen/grant_table.h>
57
58#include <xen/interface/io/netif.h>
59#include <xen/interface/memory.h>
60#include <xen/interface/grant_table.h>
61
62/* Module parameters */
63#define MAX_QUEUES_DEFAULT 8
64static unsigned int xennet_max_queues;
65module_param_named(max_queues, xennet_max_queues, uint, 0644);
66MODULE_PARM_DESC(max_queues,
67 "Maximum number of queues per virtual interface");
68
69static bool __read_mostly xennet_trusted = true;
70module_param_named(trusted, xennet_trusted, bool, 0644);
71MODULE_PARM_DESC(trusted, "Is the backend trusted");
72
73#define XENNET_TIMEOUT (5 * HZ)
74
75static const struct ethtool_ops xennet_ethtool_ops;
76
77struct netfront_cb {
78 int pull_to;
79};
80
81#define NETFRONT_SKB_CB(skb) ((struct netfront_cb *)((skb)->cb))
82
83#define RX_COPY_THRESHOLD 256
84
85#define NET_TX_RING_SIZE __CONST_RING_SIZE(xen_netif_tx, XEN_PAGE_SIZE)
86#define NET_RX_RING_SIZE __CONST_RING_SIZE(xen_netif_rx, XEN_PAGE_SIZE)
87
88/* Minimum number of Rx slots (includes slot for GSO metadata). */
89#define NET_RX_SLOTS_MIN (XEN_NETIF_NR_SLOTS_MIN + 1)
90
91/* Queue name is interface name with "-qNNN" appended */
92#define QUEUE_NAME_SIZE (IFNAMSIZ + 6)
93
94/* IRQ name is queue name with "-tx" or "-rx" appended */
95#define IRQ_NAME_SIZE (QUEUE_NAME_SIZE + 3)
96
97static DECLARE_WAIT_QUEUE_HEAD(module_wq);
98
99struct netfront_stats {
100 u64 packets;
101 u64 bytes;
102 struct u64_stats_sync syncp;
103};
104
105struct netfront_info;
106
107struct netfront_queue {
108 unsigned int id; /* Queue ID, 0-based */
109 char name[QUEUE_NAME_SIZE]; /* DEVNAME-qN */
110 struct netfront_info *info;
111
112 struct bpf_prog __rcu *xdp_prog;
113
114 struct napi_struct napi;
115
116 /* Split event channels support, tx_* == rx_* when using
117 * single event channel.
118 */
119 unsigned int tx_evtchn, rx_evtchn;
120 unsigned int tx_irq, rx_irq;
121 /* Only used when split event channels support is enabled */
122 char tx_irq_name[IRQ_NAME_SIZE]; /* DEVNAME-qN-tx */
123 char rx_irq_name[IRQ_NAME_SIZE]; /* DEVNAME-qN-rx */
124
125 spinlock_t tx_lock;
126 struct xen_netif_tx_front_ring tx;
127 int tx_ring_ref;
128
129 /*
130 * {tx,rx}_skbs store outstanding skbuffs. Free tx_skb entries
131 * are linked from tx_skb_freelist through tx_link.
132 */
133 struct sk_buff *tx_skbs[NET_TX_RING_SIZE];
134 unsigned short tx_link[NET_TX_RING_SIZE];
135#define TX_LINK_NONE 0xffff
136#define TX_PENDING 0xfffe
137 grant_ref_t gref_tx_head;
138 grant_ref_t grant_tx_ref[NET_TX_RING_SIZE];
139 struct page *grant_tx_page[NET_TX_RING_SIZE];
140 unsigned tx_skb_freelist;
141 unsigned int tx_pend_queue;
142
143 spinlock_t rx_lock ____cacheline_aligned_in_smp;
144 struct xen_netif_rx_front_ring rx;
145 int rx_ring_ref;
146
147 struct timer_list rx_refill_timer;
148
149 struct sk_buff *rx_skbs[NET_RX_RING_SIZE];
150 grant_ref_t gref_rx_head;
151 grant_ref_t grant_rx_ref[NET_RX_RING_SIZE];
152
153 unsigned int rx_rsp_unconsumed;
154 spinlock_t rx_cons_lock;
155
156 struct page_pool *page_pool;
157 struct xdp_rxq_info xdp_rxq;
158};
159
160struct netfront_info {
161 struct list_head list;
162 struct net_device *netdev;
163
164 struct xenbus_device *xbdev;
165
166 /* Multi-queue support */
167 struct netfront_queue *queues;
168
169 /* Statistics */
170 struct netfront_stats __percpu *rx_stats;
171 struct netfront_stats __percpu *tx_stats;
172
173 /* XDP state */
174 bool netback_has_xdp_headroom;
175 bool netfront_xdp_enabled;
176
177 /* Is device behaving sane? */
178 bool broken;
179
180 /* Should skbs be bounced into a zeroed buffer? */
181 bool bounce;
182
183 atomic_t rx_gso_checksum_fixup;
184};
185
186struct netfront_rx_info {
187 struct xen_netif_rx_response rx;
188 struct xen_netif_extra_info extras[XEN_NETIF_EXTRA_TYPE_MAX - 1];
189};
190
191/*
192 * Access macros for acquiring freeing slots in tx_skbs[].
193 */
194
195static void add_id_to_list(unsigned *head, unsigned short *list,
196 unsigned short id)
197{
198 list[id] = *head;
199 *head = id;
200}
201
202static unsigned short get_id_from_list(unsigned *head, unsigned short *list)
203{
204 unsigned int id = *head;
205
206 if (id != TX_LINK_NONE) {
207 *head = list[id];
208 list[id] = TX_LINK_NONE;
209 }
210 return id;
211}
212
213static int xennet_rxidx(RING_IDX idx)
214{
215 return idx & (NET_RX_RING_SIZE - 1);
216}
217
218static struct sk_buff *xennet_get_rx_skb(struct netfront_queue *queue,
219 RING_IDX ri)
220{
221 int i = xennet_rxidx(ri);
222 struct sk_buff *skb = queue->rx_skbs[i];
223 queue->rx_skbs[i] = NULL;
224 return skb;
225}
226
227static grant_ref_t xennet_get_rx_ref(struct netfront_queue *queue,
228 RING_IDX ri)
229{
230 int i = xennet_rxidx(ri);
231 grant_ref_t ref = queue->grant_rx_ref[i];
232 queue->grant_rx_ref[i] = INVALID_GRANT_REF;
233 return ref;
234}
235
236#ifdef CONFIG_SYSFS
237static const struct attribute_group xennet_dev_group;
238#endif
239
240static bool xennet_can_sg(struct net_device *dev)
241{
242 return dev->features & NETIF_F_SG;
243}
244
245
246static void rx_refill_timeout(struct timer_list *t)
247{
248 struct netfront_queue *queue = from_timer(queue, t, rx_refill_timer);
249 napi_schedule(&queue->napi);
250}
251
252static int netfront_tx_slot_available(struct netfront_queue *queue)
253{
254 return (queue->tx.req_prod_pvt - queue->tx.rsp_cons) <
255 (NET_TX_RING_SIZE - XEN_NETIF_NR_SLOTS_MIN - 1);
256}
257
258static void xennet_maybe_wake_tx(struct netfront_queue *queue)
259{
260 struct net_device *dev = queue->info->netdev;
261 struct netdev_queue *dev_queue = netdev_get_tx_queue(dev, queue->id);
262
263 if (unlikely(netif_tx_queue_stopped(dev_queue)) &&
264 netfront_tx_slot_available(queue) &&
265 likely(netif_running(dev)))
266 netif_tx_wake_queue(netdev_get_tx_queue(dev, queue->id));
267}
268
269
270static struct sk_buff *xennet_alloc_one_rx_buffer(struct netfront_queue *queue)
271{
272 struct sk_buff *skb;
273 struct page *page;
274
275 skb = __netdev_alloc_skb(queue->info->netdev,
276 RX_COPY_THRESHOLD + NET_IP_ALIGN,
277 GFP_ATOMIC | __GFP_NOWARN);
278 if (unlikely(!skb))
279 return NULL;
280
281 page = page_pool_alloc_pages(queue->page_pool,
282 GFP_ATOMIC | __GFP_NOWARN | __GFP_ZERO);
283 if (unlikely(!page)) {
284 kfree_skb(skb);
285 return NULL;
286 }
287 skb_add_rx_frag(skb, 0, page, 0, 0, PAGE_SIZE);
288 skb_mark_for_recycle(skb);
289
290 /* Align ip header to a 16 bytes boundary */
291 skb_reserve(skb, NET_IP_ALIGN);
292 skb->dev = queue->info->netdev;
293
294 return skb;
295}
296
297
298static void xennet_alloc_rx_buffers(struct netfront_queue *queue)
299{
300 RING_IDX req_prod = queue->rx.req_prod_pvt;
301 int notify;
302 int err = 0;
303
304 if (unlikely(!netif_carrier_ok(queue->info->netdev)))
305 return;
306
307 for (req_prod = queue->rx.req_prod_pvt;
308 req_prod - queue->rx.rsp_cons < NET_RX_RING_SIZE;
309 req_prod++) {
310 struct sk_buff *skb;
311 unsigned short id;
312 grant_ref_t ref;
313 struct page *page;
314 struct xen_netif_rx_request *req;
315
316 skb = xennet_alloc_one_rx_buffer(queue);
317 if (!skb) {
318 err = -ENOMEM;
319 break;
320 }
321
322 id = xennet_rxidx(req_prod);
323
324 BUG_ON(queue->rx_skbs[id]);
325 queue->rx_skbs[id] = skb;
326
327 ref = gnttab_claim_grant_reference(&queue->gref_rx_head);
328 WARN_ON_ONCE(IS_ERR_VALUE((unsigned long)(int)ref));
329 queue->grant_rx_ref[id] = ref;
330
331 page = skb_frag_page(&skb_shinfo(skb)->frags[0]);
332
333 req = RING_GET_REQUEST(&queue->rx, req_prod);
334 gnttab_page_grant_foreign_access_ref_one(ref,
335 queue->info->xbdev->otherend_id,
336 page,
337 0);
338 req->id = id;
339 req->gref = ref;
340 }
341
342 queue->rx.req_prod_pvt = req_prod;
343
344 /* Try again later if there are not enough requests or skb allocation
345 * failed.
346 * Enough requests is quantified as the sum of newly created slots and
347 * the unconsumed slots at the backend.
348 */
349 if (req_prod - queue->rx.rsp_cons < NET_RX_SLOTS_MIN ||
350 unlikely(err)) {
351 mod_timer(&queue->rx_refill_timer, jiffies + (HZ/10));
352 return;
353 }
354
355 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->rx, notify);
356 if (notify)
357 notify_remote_via_irq(queue->rx_irq);
358}
359
360static int xennet_open(struct net_device *dev)
361{
362 struct netfront_info *np = netdev_priv(dev);
363 unsigned int num_queues = dev->real_num_tx_queues;
364 unsigned int i = 0;
365 struct netfront_queue *queue = NULL;
366
367 if (!np->queues || np->broken)
368 return -ENODEV;
369
370 for (i = 0; i < num_queues; ++i) {
371 queue = &np->queues[i];
372 napi_enable(&queue->napi);
373
374 spin_lock_bh(&queue->rx_lock);
375 if (netif_carrier_ok(dev)) {
376 xennet_alloc_rx_buffers(queue);
377 queue->rx.sring->rsp_event = queue->rx.rsp_cons + 1;
378 if (RING_HAS_UNCONSUMED_RESPONSES(&queue->rx))
379 napi_schedule(&queue->napi);
380 }
381 spin_unlock_bh(&queue->rx_lock);
382 }
383
384 netif_tx_start_all_queues(dev);
385
386 return 0;
387}
388
389static bool xennet_tx_buf_gc(struct netfront_queue *queue)
390{
391 RING_IDX cons, prod;
392 unsigned short id;
393 struct sk_buff *skb;
394 bool more_to_do;
395 bool work_done = false;
396 const struct device *dev = &queue->info->netdev->dev;
397
398 BUG_ON(!netif_carrier_ok(queue->info->netdev));
399
400 do {
401 prod = queue->tx.sring->rsp_prod;
402 if (RING_RESPONSE_PROD_OVERFLOW(&queue->tx, prod)) {
403 dev_alert(dev, "Illegal number of responses %u\n",
404 prod - queue->tx.rsp_cons);
405 goto err;
406 }
407 rmb(); /* Ensure we see responses up to 'rp'. */
408
409 for (cons = queue->tx.rsp_cons; cons != prod; cons++) {
410 struct xen_netif_tx_response txrsp;
411
412 work_done = true;
413
414 RING_COPY_RESPONSE(&queue->tx, cons, &txrsp);
415 if (txrsp.status == XEN_NETIF_RSP_NULL)
416 continue;
417
418 id = txrsp.id;
419 if (id >= RING_SIZE(&queue->tx)) {
420 dev_alert(dev,
421 "Response has incorrect id (%u)\n",
422 id);
423 goto err;
424 }
425 if (queue->tx_link[id] != TX_PENDING) {
426 dev_alert(dev,
427 "Response for inactive request\n");
428 goto err;
429 }
430
431 queue->tx_link[id] = TX_LINK_NONE;
432 skb = queue->tx_skbs[id];
433 queue->tx_skbs[id] = NULL;
434 if (unlikely(!gnttab_end_foreign_access_ref(
435 queue->grant_tx_ref[id]))) {
436 dev_alert(dev,
437 "Grant still in use by backend domain\n");
438 goto err;
439 }
440 gnttab_release_grant_reference(
441 &queue->gref_tx_head, queue->grant_tx_ref[id]);
442 queue->grant_tx_ref[id] = INVALID_GRANT_REF;
443 queue->grant_tx_page[id] = NULL;
444 add_id_to_list(&queue->tx_skb_freelist, queue->tx_link, id);
445 dev_kfree_skb_irq(skb);
446 }
447
448 queue->tx.rsp_cons = prod;
449
450 RING_FINAL_CHECK_FOR_RESPONSES(&queue->tx, more_to_do);
451 } while (more_to_do);
452
453 xennet_maybe_wake_tx(queue);
454
455 return work_done;
456
457 err:
458 queue->info->broken = true;
459 dev_alert(dev, "Disabled for further use\n");
460
461 return work_done;
462}
463
464struct xennet_gnttab_make_txreq {
465 struct netfront_queue *queue;
466 struct sk_buff *skb;
467 struct page *page;
468 struct xen_netif_tx_request *tx; /* Last request on ring page */
469 struct xen_netif_tx_request tx_local; /* Last request local copy*/
470 unsigned int size;
471};
472
473static void xennet_tx_setup_grant(unsigned long gfn, unsigned int offset,
474 unsigned int len, void *data)
475{
476 struct xennet_gnttab_make_txreq *info = data;
477 unsigned int id;
478 struct xen_netif_tx_request *tx;
479 grant_ref_t ref;
480 /* convenient aliases */
481 struct page *page = info->page;
482 struct netfront_queue *queue = info->queue;
483 struct sk_buff *skb = info->skb;
484
485 id = get_id_from_list(&queue->tx_skb_freelist, queue->tx_link);
486 tx = RING_GET_REQUEST(&queue->tx, queue->tx.req_prod_pvt++);
487 ref = gnttab_claim_grant_reference(&queue->gref_tx_head);
488 WARN_ON_ONCE(IS_ERR_VALUE((unsigned long)(int)ref));
489
490 gnttab_grant_foreign_access_ref(ref, queue->info->xbdev->otherend_id,
491 gfn, GNTMAP_readonly);
492
493 queue->tx_skbs[id] = skb;
494 queue->grant_tx_page[id] = page;
495 queue->grant_tx_ref[id] = ref;
496
497 info->tx_local.id = id;
498 info->tx_local.gref = ref;
499 info->tx_local.offset = offset;
500 info->tx_local.size = len;
501 info->tx_local.flags = 0;
502
503 *tx = info->tx_local;
504
505 /*
506 * Put the request in the pending queue, it will be set to be pending
507 * when the producer index is about to be raised.
508 */
509 add_id_to_list(&queue->tx_pend_queue, queue->tx_link, id);
510
511 info->tx = tx;
512 info->size += info->tx_local.size;
513}
514
515static struct xen_netif_tx_request *xennet_make_first_txreq(
516 struct xennet_gnttab_make_txreq *info,
517 unsigned int offset, unsigned int len)
518{
519 info->size = 0;
520
521 gnttab_for_one_grant(info->page, offset, len, xennet_tx_setup_grant, info);
522
523 return info->tx;
524}
525
526static void xennet_make_one_txreq(unsigned long gfn, unsigned int offset,
527 unsigned int len, void *data)
528{
529 struct xennet_gnttab_make_txreq *info = data;
530
531 info->tx->flags |= XEN_NETTXF_more_data;
532 skb_get(info->skb);
533 xennet_tx_setup_grant(gfn, offset, len, data);
534}
535
536static void xennet_make_txreqs(
537 struct xennet_gnttab_make_txreq *info,
538 struct page *page,
539 unsigned int offset, unsigned int len)
540{
541 /* Skip unused frames from start of page */
542 page += offset >> PAGE_SHIFT;
543 offset &= ~PAGE_MASK;
544
545 while (len) {
546 info->page = page;
547 info->size = 0;
548
549 gnttab_foreach_grant_in_range(page, offset, len,
550 xennet_make_one_txreq,
551 info);
552
553 page++;
554 offset = 0;
555 len -= info->size;
556 }
557}
558
559/*
560 * Count how many ring slots are required to send this skb. Each frag
561 * might be a compound page.
562 */
563static int xennet_count_skb_slots(struct sk_buff *skb)
564{
565 int i, frags = skb_shinfo(skb)->nr_frags;
566 int slots;
567
568 slots = gnttab_count_grant(offset_in_page(skb->data),
569 skb_headlen(skb));
570
571 for (i = 0; i < frags; i++) {
572 skb_frag_t *frag = skb_shinfo(skb)->frags + i;
573 unsigned long size = skb_frag_size(frag);
574 unsigned long offset = skb_frag_off(frag);
575
576 /* Skip unused frames from start of page */
577 offset &= ~PAGE_MASK;
578
579 slots += gnttab_count_grant(offset, size);
580 }
581
582 return slots;
583}
584
585static u16 xennet_select_queue(struct net_device *dev, struct sk_buff *skb,
586 struct net_device *sb_dev)
587{
588 unsigned int num_queues = dev->real_num_tx_queues;
589 u32 hash;
590 u16 queue_idx;
591
592 /* First, check if there is only one queue */
593 if (num_queues == 1) {
594 queue_idx = 0;
595 } else {
596 hash = skb_get_hash(skb);
597 queue_idx = hash % num_queues;
598 }
599
600 return queue_idx;
601}
602
603static void xennet_mark_tx_pending(struct netfront_queue *queue)
604{
605 unsigned int i;
606
607 while ((i = get_id_from_list(&queue->tx_pend_queue, queue->tx_link)) !=
608 TX_LINK_NONE)
609 queue->tx_link[i] = TX_PENDING;
610}
611
612static int xennet_xdp_xmit_one(struct net_device *dev,
613 struct netfront_queue *queue,
614 struct xdp_frame *xdpf)
615{
616 struct netfront_info *np = netdev_priv(dev);
617 struct netfront_stats *tx_stats = this_cpu_ptr(np->tx_stats);
618 struct xennet_gnttab_make_txreq info = {
619 .queue = queue,
620 .skb = NULL,
621 .page = virt_to_page(xdpf->data),
622 };
623 int notify;
624
625 xennet_make_first_txreq(&info,
626 offset_in_page(xdpf->data),
627 xdpf->len);
628
629 xennet_mark_tx_pending(queue);
630
631 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->tx, notify);
632 if (notify)
633 notify_remote_via_irq(queue->tx_irq);
634
635 u64_stats_update_begin(&tx_stats->syncp);
636 tx_stats->bytes += xdpf->len;
637 tx_stats->packets++;
638 u64_stats_update_end(&tx_stats->syncp);
639
640 xennet_tx_buf_gc(queue);
641
642 return 0;
643}
644
645static int xennet_xdp_xmit(struct net_device *dev, int n,
646 struct xdp_frame **frames, u32 flags)
647{
648 unsigned int num_queues = dev->real_num_tx_queues;
649 struct netfront_info *np = netdev_priv(dev);
650 struct netfront_queue *queue = NULL;
651 unsigned long irq_flags;
652 int nxmit = 0;
653 int i;
654
655 if (unlikely(np->broken))
656 return -ENODEV;
657 if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK))
658 return -EINVAL;
659
660 queue = &np->queues[smp_processor_id() % num_queues];
661
662 spin_lock_irqsave(&queue->tx_lock, irq_flags);
663 for (i = 0; i < n; i++) {
664 struct xdp_frame *xdpf = frames[i];
665
666 if (!xdpf)
667 continue;
668 if (xennet_xdp_xmit_one(dev, queue, xdpf))
669 break;
670 nxmit++;
671 }
672 spin_unlock_irqrestore(&queue->tx_lock, irq_flags);
673
674 return nxmit;
675}
676
677static struct sk_buff *bounce_skb(const struct sk_buff *skb)
678{
679 unsigned int headerlen = skb_headroom(skb);
680 /* Align size to allocate full pages and avoid contiguous data leaks */
681 unsigned int size = ALIGN(skb_end_offset(skb) + skb->data_len,
682 XEN_PAGE_SIZE);
683 struct sk_buff *n = alloc_skb(size, GFP_ATOMIC | __GFP_ZERO);
684
685 if (!n)
686 return NULL;
687
688 if (!IS_ALIGNED((uintptr_t)n->head, XEN_PAGE_SIZE)) {
689 WARN_ONCE(1, "misaligned skb allocated\n");
690 kfree_skb(n);
691 return NULL;
692 }
693
694 /* Set the data pointer */
695 skb_reserve(n, headerlen);
696 /* Set the tail pointer and length */
697 skb_put(n, skb->len);
698
699 BUG_ON(skb_copy_bits(skb, -headerlen, n->head, headerlen + skb->len));
700
701 skb_copy_header(n, skb);
702 return n;
703}
704
705#define MAX_XEN_SKB_FRAGS (65536 / XEN_PAGE_SIZE + 1)
706
707static netdev_tx_t xennet_start_xmit(struct sk_buff *skb, struct net_device *dev)
708{
709 struct netfront_info *np = netdev_priv(dev);
710 struct netfront_stats *tx_stats = this_cpu_ptr(np->tx_stats);
711 struct xen_netif_tx_request *first_tx;
712 unsigned int i;
713 int notify;
714 int slots;
715 struct page *page;
716 unsigned int offset;
717 unsigned int len;
718 unsigned long flags;
719 struct netfront_queue *queue = NULL;
720 struct xennet_gnttab_make_txreq info = { };
721 unsigned int num_queues = dev->real_num_tx_queues;
722 u16 queue_index;
723 struct sk_buff *nskb;
724
725 /* Drop the packet if no queues are set up */
726 if (num_queues < 1)
727 goto drop;
728 if (unlikely(np->broken))
729 goto drop;
730 /* Determine which queue to transmit this SKB on */
731 queue_index = skb_get_queue_mapping(skb);
732 queue = &np->queues[queue_index];
733
734 /* If skb->len is too big for wire format, drop skb and alert
735 * user about misconfiguration.
736 */
737 if (unlikely(skb->len > XEN_NETIF_MAX_TX_SIZE)) {
738 net_alert_ratelimited(
739 "xennet: skb->len = %u, too big for wire format\n",
740 skb->len);
741 goto drop;
742 }
743
744 slots = xennet_count_skb_slots(skb);
745 if (unlikely(slots > MAX_XEN_SKB_FRAGS + 1)) {
746 net_dbg_ratelimited("xennet: skb rides the rocket: %d slots, %d bytes\n",
747 slots, skb->len);
748 if (skb_linearize(skb))
749 goto drop;
750 }
751
752 page = virt_to_page(skb->data);
753 offset = offset_in_page(skb->data);
754
755 /* The first req should be at least ETH_HLEN size or the packet will be
756 * dropped by netback.
757 *
758 * If the backend is not trusted bounce all data to zeroed pages to
759 * avoid exposing contiguous data on the granted page not belonging to
760 * the skb.
761 */
762 if (np->bounce || unlikely(PAGE_SIZE - offset < ETH_HLEN)) {
763 nskb = bounce_skb(skb);
764 if (!nskb)
765 goto drop;
766 dev_consume_skb_any(skb);
767 skb = nskb;
768 page = virt_to_page(skb->data);
769 offset = offset_in_page(skb->data);
770 }
771
772 len = skb_headlen(skb);
773
774 spin_lock_irqsave(&queue->tx_lock, flags);
775
776 if (unlikely(!netif_carrier_ok(dev) ||
777 (slots > 1 && !xennet_can_sg(dev)) ||
778 netif_needs_gso(skb, netif_skb_features(skb)))) {
779 spin_unlock_irqrestore(&queue->tx_lock, flags);
780 goto drop;
781 }
782
783 /* First request for the linear area. */
784 info.queue = queue;
785 info.skb = skb;
786 info.page = page;
787 first_tx = xennet_make_first_txreq(&info, offset, len);
788 offset += info.tx_local.size;
789 if (offset == PAGE_SIZE) {
790 page++;
791 offset = 0;
792 }
793 len -= info.tx_local.size;
794
795 if (skb->ip_summed == CHECKSUM_PARTIAL)
796 /* local packet? */
797 first_tx->flags |= XEN_NETTXF_csum_blank |
798 XEN_NETTXF_data_validated;
799 else if (skb->ip_summed == CHECKSUM_UNNECESSARY)
800 /* remote but checksummed. */
801 first_tx->flags |= XEN_NETTXF_data_validated;
802
803 /* Optional extra info after the first request. */
804 if (skb_shinfo(skb)->gso_size) {
805 struct xen_netif_extra_info *gso;
806
807 gso = (struct xen_netif_extra_info *)
808 RING_GET_REQUEST(&queue->tx, queue->tx.req_prod_pvt++);
809
810 first_tx->flags |= XEN_NETTXF_extra_info;
811
812 gso->u.gso.size = skb_shinfo(skb)->gso_size;
813 gso->u.gso.type = (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6) ?
814 XEN_NETIF_GSO_TYPE_TCPV6 :
815 XEN_NETIF_GSO_TYPE_TCPV4;
816 gso->u.gso.pad = 0;
817 gso->u.gso.features = 0;
818
819 gso->type = XEN_NETIF_EXTRA_TYPE_GSO;
820 gso->flags = 0;
821 }
822
823 /* Requests for the rest of the linear area. */
824 xennet_make_txreqs(&info, page, offset, len);
825
826 /* Requests for all the frags. */
827 for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
828 skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
829 xennet_make_txreqs(&info, skb_frag_page(frag),
830 skb_frag_off(frag),
831 skb_frag_size(frag));
832 }
833
834 /* First request has the packet length. */
835 first_tx->size = skb->len;
836
837 /* timestamp packet in software */
838 skb_tx_timestamp(skb);
839
840 xennet_mark_tx_pending(queue);
841
842 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->tx, notify);
843 if (notify)
844 notify_remote_via_irq(queue->tx_irq);
845
846 u64_stats_update_begin(&tx_stats->syncp);
847 tx_stats->bytes += skb->len;
848 tx_stats->packets++;
849 u64_stats_update_end(&tx_stats->syncp);
850
851 /* Note: It is not safe to access skb after xennet_tx_buf_gc()! */
852 xennet_tx_buf_gc(queue);
853
854 if (!netfront_tx_slot_available(queue))
855 netif_tx_stop_queue(netdev_get_tx_queue(dev, queue->id));
856
857 spin_unlock_irqrestore(&queue->tx_lock, flags);
858
859 return NETDEV_TX_OK;
860
861 drop:
862 dev->stats.tx_dropped++;
863 dev_kfree_skb_any(skb);
864 return NETDEV_TX_OK;
865}
866
867static int xennet_close(struct net_device *dev)
868{
869 struct netfront_info *np = netdev_priv(dev);
870 unsigned int num_queues = np->queues ? dev->real_num_tx_queues : 0;
871 unsigned int i;
872 struct netfront_queue *queue;
873 netif_tx_stop_all_queues(np->netdev);
874 for (i = 0; i < num_queues; ++i) {
875 queue = &np->queues[i];
876 napi_disable(&queue->napi);
877 }
878 return 0;
879}
880
881static void xennet_destroy_queues(struct netfront_info *info)
882{
883 unsigned int i;
884
885 if (!info->queues)
886 return;
887
888 for (i = 0; i < info->netdev->real_num_tx_queues; i++) {
889 struct netfront_queue *queue = &info->queues[i];
890
891 if (netif_running(info->netdev))
892 napi_disable(&queue->napi);
893 netif_napi_del(&queue->napi);
894 }
895
896 kfree(info->queues);
897 info->queues = NULL;
898}
899
900static void xennet_uninit(struct net_device *dev)
901{
902 struct netfront_info *np = netdev_priv(dev);
903 xennet_destroy_queues(np);
904}
905
906static void xennet_set_rx_rsp_cons(struct netfront_queue *queue, RING_IDX val)
907{
908 unsigned long flags;
909
910 spin_lock_irqsave(&queue->rx_cons_lock, flags);
911 queue->rx.rsp_cons = val;
912 queue->rx_rsp_unconsumed = XEN_RING_NR_UNCONSUMED_RESPONSES(&queue->rx);
913 spin_unlock_irqrestore(&queue->rx_cons_lock, flags);
914}
915
916static void xennet_move_rx_slot(struct netfront_queue *queue, struct sk_buff *skb,
917 grant_ref_t ref)
918{
919 int new = xennet_rxidx(queue->rx.req_prod_pvt);
920
921 BUG_ON(queue->rx_skbs[new]);
922 queue->rx_skbs[new] = skb;
923 queue->grant_rx_ref[new] = ref;
924 RING_GET_REQUEST(&queue->rx, queue->rx.req_prod_pvt)->id = new;
925 RING_GET_REQUEST(&queue->rx, queue->rx.req_prod_pvt)->gref = ref;
926 queue->rx.req_prod_pvt++;
927}
928
929static int xennet_get_extras(struct netfront_queue *queue,
930 struct xen_netif_extra_info *extras,
931 RING_IDX rp)
932
933{
934 struct xen_netif_extra_info extra;
935 struct device *dev = &queue->info->netdev->dev;
936 RING_IDX cons = queue->rx.rsp_cons;
937 int err = 0;
938
939 do {
940 struct sk_buff *skb;
941 grant_ref_t ref;
942
943 if (unlikely(cons + 1 == rp)) {
944 if (net_ratelimit())
945 dev_warn(dev, "Missing extra info\n");
946 err = -EBADR;
947 break;
948 }
949
950 RING_COPY_RESPONSE(&queue->rx, ++cons, &extra);
951
952 if (unlikely(!extra.type ||
953 extra.type >= XEN_NETIF_EXTRA_TYPE_MAX)) {
954 if (net_ratelimit())
955 dev_warn(dev, "Invalid extra type: %d\n",
956 extra.type);
957 err = -EINVAL;
958 } else {
959 extras[extra.type - 1] = extra;
960 }
961
962 skb = xennet_get_rx_skb(queue, cons);
963 ref = xennet_get_rx_ref(queue, cons);
964 xennet_move_rx_slot(queue, skb, ref);
965 } while (extra.flags & XEN_NETIF_EXTRA_FLAG_MORE);
966
967 xennet_set_rx_rsp_cons(queue, cons);
968 return err;
969}
970
971static u32 xennet_run_xdp(struct netfront_queue *queue, struct page *pdata,
972 struct xen_netif_rx_response *rx, struct bpf_prog *prog,
973 struct xdp_buff *xdp, bool *need_xdp_flush)
974{
975 struct xdp_frame *xdpf;
976 u32 len = rx->status;
977 u32 act;
978 int err;
979
980 xdp_init_buff(xdp, XEN_PAGE_SIZE - XDP_PACKET_HEADROOM,
981 &queue->xdp_rxq);
982 xdp_prepare_buff(xdp, page_address(pdata), XDP_PACKET_HEADROOM,
983 len, false);
984
985 act = bpf_prog_run_xdp(prog, xdp);
986 switch (act) {
987 case XDP_TX:
988 get_page(pdata);
989 xdpf = xdp_convert_buff_to_frame(xdp);
990 err = xennet_xdp_xmit(queue->info->netdev, 1, &xdpf, 0);
991 if (unlikely(!err))
992 xdp_return_frame_rx_napi(xdpf);
993 else if (unlikely(err < 0))
994 trace_xdp_exception(queue->info->netdev, prog, act);
995 break;
996 case XDP_REDIRECT:
997 get_page(pdata);
998 err = xdp_do_redirect(queue->info->netdev, xdp, prog);
999 *need_xdp_flush = true;
1000 if (unlikely(err))
1001 trace_xdp_exception(queue->info->netdev, prog, act);
1002 break;
1003 case XDP_PASS:
1004 case XDP_DROP:
1005 break;
1006
1007 case XDP_ABORTED:
1008 trace_xdp_exception(queue->info->netdev, prog, act);
1009 break;
1010
1011 default:
1012 bpf_warn_invalid_xdp_action(queue->info->netdev, prog, act);
1013 }
1014
1015 return act;
1016}
1017
1018static int xennet_get_responses(struct netfront_queue *queue,
1019 struct netfront_rx_info *rinfo, RING_IDX rp,
1020 struct sk_buff_head *list,
1021 bool *need_xdp_flush)
1022{
1023 struct xen_netif_rx_response *rx = &rinfo->rx, rx_local;
1024 int max = XEN_NETIF_NR_SLOTS_MIN + (rx->status <= RX_COPY_THRESHOLD);
1025 RING_IDX cons = queue->rx.rsp_cons;
1026 struct sk_buff *skb = xennet_get_rx_skb(queue, cons);
1027 struct xen_netif_extra_info *extras = rinfo->extras;
1028 grant_ref_t ref = xennet_get_rx_ref(queue, cons);
1029 struct device *dev = &queue->info->netdev->dev;
1030 struct bpf_prog *xdp_prog;
1031 struct xdp_buff xdp;
1032 int slots = 1;
1033 int err = 0;
1034 u32 verdict;
1035
1036 if (rx->flags & XEN_NETRXF_extra_info) {
1037 err = xennet_get_extras(queue, extras, rp);
1038 if (!err) {
1039 if (extras[XEN_NETIF_EXTRA_TYPE_XDP - 1].type) {
1040 struct xen_netif_extra_info *xdp;
1041
1042 xdp = &extras[XEN_NETIF_EXTRA_TYPE_XDP - 1];
1043 rx->offset = xdp->u.xdp.headroom;
1044 }
1045 }
1046 cons = queue->rx.rsp_cons;
1047 }
1048
1049 for (;;) {
1050 /*
1051 * This definitely indicates a bug, either in this driver or in
1052 * the backend driver. In future this should flag the bad
1053 * situation to the system controller to reboot the backend.
1054 */
1055 if (ref == INVALID_GRANT_REF) {
1056 if (net_ratelimit())
1057 dev_warn(dev, "Bad rx response id %d.\n",
1058 rx->id);
1059 err = -EINVAL;
1060 goto next;
1061 }
1062
1063 if (unlikely(rx->status < 0 ||
1064 rx->offset + rx->status > XEN_PAGE_SIZE)) {
1065 if (net_ratelimit())
1066 dev_warn(dev, "rx->offset: %u, size: %d\n",
1067 rx->offset, rx->status);
1068 xennet_move_rx_slot(queue, skb, ref);
1069 err = -EINVAL;
1070 goto next;
1071 }
1072
1073 if (!gnttab_end_foreign_access_ref(ref)) {
1074 dev_alert(dev,
1075 "Grant still in use by backend domain\n");
1076 queue->info->broken = true;
1077 dev_alert(dev, "Disabled for further use\n");
1078 return -EINVAL;
1079 }
1080
1081 gnttab_release_grant_reference(&queue->gref_rx_head, ref);
1082
1083 rcu_read_lock();
1084 xdp_prog = rcu_dereference(queue->xdp_prog);
1085 if (xdp_prog) {
1086 if (!(rx->flags & XEN_NETRXF_more_data)) {
1087 /* currently only a single page contains data */
1088 verdict = xennet_run_xdp(queue,
1089 skb_frag_page(&skb_shinfo(skb)->frags[0]),
1090 rx, xdp_prog, &xdp, need_xdp_flush);
1091 if (verdict != XDP_PASS)
1092 err = -EINVAL;
1093 } else {
1094 /* drop the frame */
1095 err = -EINVAL;
1096 }
1097 }
1098 rcu_read_unlock();
1099
1100 __skb_queue_tail(list, skb);
1101
1102next:
1103 if (!(rx->flags & XEN_NETRXF_more_data))
1104 break;
1105
1106 if (cons + slots == rp) {
1107 if (net_ratelimit())
1108 dev_warn(dev, "Need more slots\n");
1109 err = -ENOENT;
1110 break;
1111 }
1112
1113 RING_COPY_RESPONSE(&queue->rx, cons + slots, &rx_local);
1114 rx = &rx_local;
1115 skb = xennet_get_rx_skb(queue, cons + slots);
1116 ref = xennet_get_rx_ref(queue, cons + slots);
1117 slots++;
1118 }
1119
1120 if (unlikely(slots > max)) {
1121 if (net_ratelimit())
1122 dev_warn(dev, "Too many slots\n");
1123 err = -E2BIG;
1124 }
1125
1126 if (unlikely(err))
1127 xennet_set_rx_rsp_cons(queue, cons + slots);
1128
1129 return err;
1130}
1131
1132static int xennet_set_skb_gso(struct sk_buff *skb,
1133 struct xen_netif_extra_info *gso)
1134{
1135 if (!gso->u.gso.size) {
1136 if (net_ratelimit())
1137 pr_warn("GSO size must not be zero\n");
1138 return -EINVAL;
1139 }
1140
1141 if (gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV4 &&
1142 gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV6) {
1143 if (net_ratelimit())
1144 pr_warn("Bad GSO type %d\n", gso->u.gso.type);
1145 return -EINVAL;
1146 }
1147
1148 skb_shinfo(skb)->gso_size = gso->u.gso.size;
1149 skb_shinfo(skb)->gso_type =
1150 (gso->u.gso.type == XEN_NETIF_GSO_TYPE_TCPV4) ?
1151 SKB_GSO_TCPV4 :
1152 SKB_GSO_TCPV6;
1153
1154 /* Header must be checked, and gso_segs computed. */
1155 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
1156 skb_shinfo(skb)->gso_segs = 0;
1157
1158 return 0;
1159}
1160
1161static int xennet_fill_frags(struct netfront_queue *queue,
1162 struct sk_buff *skb,
1163 struct sk_buff_head *list)
1164{
1165 RING_IDX cons = queue->rx.rsp_cons;
1166 struct sk_buff *nskb;
1167
1168 while ((nskb = __skb_dequeue(list))) {
1169 struct xen_netif_rx_response rx;
1170 skb_frag_t *nfrag = &skb_shinfo(nskb)->frags[0];
1171
1172 RING_COPY_RESPONSE(&queue->rx, ++cons, &rx);
1173
1174 if (skb_shinfo(skb)->nr_frags == MAX_SKB_FRAGS) {
1175 unsigned int pull_to = NETFRONT_SKB_CB(skb)->pull_to;
1176
1177 BUG_ON(pull_to < skb_headlen(skb));
1178 __pskb_pull_tail(skb, pull_to - skb_headlen(skb));
1179 }
1180 if (unlikely(skb_shinfo(skb)->nr_frags >= MAX_SKB_FRAGS)) {
1181 xennet_set_rx_rsp_cons(queue,
1182 ++cons + skb_queue_len(list));
1183 kfree_skb(nskb);
1184 return -ENOENT;
1185 }
1186
1187 skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags,
1188 skb_frag_page(nfrag),
1189 rx.offset, rx.status, PAGE_SIZE);
1190
1191 skb_shinfo(nskb)->nr_frags = 0;
1192 kfree_skb(nskb);
1193 }
1194
1195 xennet_set_rx_rsp_cons(queue, cons);
1196
1197 return 0;
1198}
1199
1200static int checksum_setup(struct net_device *dev, struct sk_buff *skb)
1201{
1202 bool recalculate_partial_csum = false;
1203
1204 /*
1205 * A GSO SKB must be CHECKSUM_PARTIAL. However some buggy
1206 * peers can fail to set NETRXF_csum_blank when sending a GSO
1207 * frame. In this case force the SKB to CHECKSUM_PARTIAL and
1208 * recalculate the partial checksum.
1209 */
1210 if (skb->ip_summed != CHECKSUM_PARTIAL && skb_is_gso(skb)) {
1211 struct netfront_info *np = netdev_priv(dev);
1212 atomic_inc(&np->rx_gso_checksum_fixup);
1213 skb->ip_summed = CHECKSUM_PARTIAL;
1214 recalculate_partial_csum = true;
1215 }
1216
1217 /* A non-CHECKSUM_PARTIAL SKB does not require setup. */
1218 if (skb->ip_summed != CHECKSUM_PARTIAL)
1219 return 0;
1220
1221 return skb_checksum_setup(skb, recalculate_partial_csum);
1222}
1223
1224static int handle_incoming_queue(struct netfront_queue *queue,
1225 struct sk_buff_head *rxq)
1226{
1227 struct netfront_stats *rx_stats = this_cpu_ptr(queue->info->rx_stats);
1228 int packets_dropped = 0;
1229 struct sk_buff *skb;
1230
1231 while ((skb = __skb_dequeue(rxq)) != NULL) {
1232 int pull_to = NETFRONT_SKB_CB(skb)->pull_to;
1233
1234 if (pull_to > skb_headlen(skb))
1235 __pskb_pull_tail(skb, pull_to - skb_headlen(skb));
1236
1237 /* Ethernet work: Delayed to here as it peeks the header. */
1238 skb->protocol = eth_type_trans(skb, queue->info->netdev);
1239 skb_reset_network_header(skb);
1240
1241 if (checksum_setup(queue->info->netdev, skb)) {
1242 kfree_skb(skb);
1243 packets_dropped++;
1244 queue->info->netdev->stats.rx_errors++;
1245 continue;
1246 }
1247
1248 u64_stats_update_begin(&rx_stats->syncp);
1249 rx_stats->packets++;
1250 rx_stats->bytes += skb->len;
1251 u64_stats_update_end(&rx_stats->syncp);
1252
1253 /* Pass it up. */
1254 napi_gro_receive(&queue->napi, skb);
1255 }
1256
1257 return packets_dropped;
1258}
1259
1260static int xennet_poll(struct napi_struct *napi, int budget)
1261{
1262 struct netfront_queue *queue = container_of(napi, struct netfront_queue, napi);
1263 struct net_device *dev = queue->info->netdev;
1264 struct sk_buff *skb;
1265 struct netfront_rx_info rinfo;
1266 struct xen_netif_rx_response *rx = &rinfo.rx;
1267 struct xen_netif_extra_info *extras = rinfo.extras;
1268 RING_IDX i, rp;
1269 int work_done;
1270 struct sk_buff_head rxq;
1271 struct sk_buff_head errq;
1272 struct sk_buff_head tmpq;
1273 int err;
1274 bool need_xdp_flush = false;
1275
1276 spin_lock(&queue->rx_lock);
1277
1278 skb_queue_head_init(&rxq);
1279 skb_queue_head_init(&errq);
1280 skb_queue_head_init(&tmpq);
1281
1282 rp = queue->rx.sring->rsp_prod;
1283 if (RING_RESPONSE_PROD_OVERFLOW(&queue->rx, rp)) {
1284 dev_alert(&dev->dev, "Illegal number of responses %u\n",
1285 rp - queue->rx.rsp_cons);
1286 queue->info->broken = true;
1287 spin_unlock(&queue->rx_lock);
1288 return 0;
1289 }
1290 rmb(); /* Ensure we see queued responses up to 'rp'. */
1291
1292 i = queue->rx.rsp_cons;
1293 work_done = 0;
1294 while ((i != rp) && (work_done < budget)) {
1295 RING_COPY_RESPONSE(&queue->rx, i, rx);
1296 memset(extras, 0, sizeof(rinfo.extras));
1297
1298 err = xennet_get_responses(queue, &rinfo, rp, &tmpq,
1299 &need_xdp_flush);
1300
1301 if (unlikely(err)) {
1302 if (queue->info->broken) {
1303 spin_unlock(&queue->rx_lock);
1304 return 0;
1305 }
1306err:
1307 while ((skb = __skb_dequeue(&tmpq)))
1308 __skb_queue_tail(&errq, skb);
1309 dev->stats.rx_errors++;
1310 i = queue->rx.rsp_cons;
1311 continue;
1312 }
1313
1314 skb = __skb_dequeue(&tmpq);
1315
1316 if (extras[XEN_NETIF_EXTRA_TYPE_GSO - 1].type) {
1317 struct xen_netif_extra_info *gso;
1318 gso = &extras[XEN_NETIF_EXTRA_TYPE_GSO - 1];
1319
1320 if (unlikely(xennet_set_skb_gso(skb, gso))) {
1321 __skb_queue_head(&tmpq, skb);
1322 xennet_set_rx_rsp_cons(queue,
1323 queue->rx.rsp_cons +
1324 skb_queue_len(&tmpq));
1325 goto err;
1326 }
1327 }
1328
1329 NETFRONT_SKB_CB(skb)->pull_to = rx->status;
1330 if (NETFRONT_SKB_CB(skb)->pull_to > RX_COPY_THRESHOLD)
1331 NETFRONT_SKB_CB(skb)->pull_to = RX_COPY_THRESHOLD;
1332
1333 skb_frag_off_set(&skb_shinfo(skb)->frags[0], rx->offset);
1334 skb_frag_size_set(&skb_shinfo(skb)->frags[0], rx->status);
1335 skb->data_len = rx->status;
1336 skb->len += rx->status;
1337
1338 if (unlikely(xennet_fill_frags(queue, skb, &tmpq)))
1339 goto err;
1340
1341 if (rx->flags & XEN_NETRXF_csum_blank)
1342 skb->ip_summed = CHECKSUM_PARTIAL;
1343 else if (rx->flags & XEN_NETRXF_data_validated)
1344 skb->ip_summed = CHECKSUM_UNNECESSARY;
1345
1346 __skb_queue_tail(&rxq, skb);
1347
1348 i = queue->rx.rsp_cons + 1;
1349 xennet_set_rx_rsp_cons(queue, i);
1350 work_done++;
1351 }
1352 if (need_xdp_flush)
1353 xdp_do_flush();
1354
1355 __skb_queue_purge(&errq);
1356
1357 work_done -= handle_incoming_queue(queue, &rxq);
1358
1359 xennet_alloc_rx_buffers(queue);
1360
1361 if (work_done < budget) {
1362 int more_to_do = 0;
1363
1364 napi_complete_done(napi, work_done);
1365
1366 RING_FINAL_CHECK_FOR_RESPONSES(&queue->rx, more_to_do);
1367 if (more_to_do)
1368 napi_schedule(napi);
1369 }
1370
1371 spin_unlock(&queue->rx_lock);
1372
1373 return work_done;
1374}
1375
1376static int xennet_change_mtu(struct net_device *dev, int mtu)
1377{
1378 int max = xennet_can_sg(dev) ? XEN_NETIF_MAX_TX_SIZE : ETH_DATA_LEN;
1379
1380 if (mtu > max)
1381 return -EINVAL;
1382 WRITE_ONCE(dev->mtu, mtu);
1383 return 0;
1384}
1385
1386static void xennet_get_stats64(struct net_device *dev,
1387 struct rtnl_link_stats64 *tot)
1388{
1389 struct netfront_info *np = netdev_priv(dev);
1390 int cpu;
1391
1392 for_each_possible_cpu(cpu) {
1393 struct netfront_stats *rx_stats = per_cpu_ptr(np->rx_stats, cpu);
1394 struct netfront_stats *tx_stats = per_cpu_ptr(np->tx_stats, cpu);
1395 u64 rx_packets, rx_bytes, tx_packets, tx_bytes;
1396 unsigned int start;
1397
1398 do {
1399 start = u64_stats_fetch_begin(&tx_stats->syncp);
1400 tx_packets = tx_stats->packets;
1401 tx_bytes = tx_stats->bytes;
1402 } while (u64_stats_fetch_retry(&tx_stats->syncp, start));
1403
1404 do {
1405 start = u64_stats_fetch_begin(&rx_stats->syncp);
1406 rx_packets = rx_stats->packets;
1407 rx_bytes = rx_stats->bytes;
1408 } while (u64_stats_fetch_retry(&rx_stats->syncp, start));
1409
1410 tot->rx_packets += rx_packets;
1411 tot->tx_packets += tx_packets;
1412 tot->rx_bytes += rx_bytes;
1413 tot->tx_bytes += tx_bytes;
1414 }
1415
1416 tot->rx_errors = dev->stats.rx_errors;
1417 tot->tx_dropped = dev->stats.tx_dropped;
1418}
1419
1420static void xennet_release_tx_bufs(struct netfront_queue *queue)
1421{
1422 struct sk_buff *skb;
1423 int i;
1424
1425 for (i = 0; i < NET_TX_RING_SIZE; i++) {
1426 /* Skip over entries which are actually freelist references */
1427 if (!queue->tx_skbs[i])
1428 continue;
1429
1430 skb = queue->tx_skbs[i];
1431 queue->tx_skbs[i] = NULL;
1432 get_page(queue->grant_tx_page[i]);
1433 gnttab_end_foreign_access(queue->grant_tx_ref[i],
1434 queue->grant_tx_page[i]);
1435 queue->grant_tx_page[i] = NULL;
1436 queue->grant_tx_ref[i] = INVALID_GRANT_REF;
1437 add_id_to_list(&queue->tx_skb_freelist, queue->tx_link, i);
1438 dev_kfree_skb_irq(skb);
1439 }
1440}
1441
1442static void xennet_release_rx_bufs(struct netfront_queue *queue)
1443{
1444 int id, ref;
1445
1446 spin_lock_bh(&queue->rx_lock);
1447
1448 for (id = 0; id < NET_RX_RING_SIZE; id++) {
1449 struct sk_buff *skb;
1450 struct page *page;
1451
1452 skb = queue->rx_skbs[id];
1453 if (!skb)
1454 continue;
1455
1456 ref = queue->grant_rx_ref[id];
1457 if (ref == INVALID_GRANT_REF)
1458 continue;
1459
1460 page = skb_frag_page(&skb_shinfo(skb)->frags[0]);
1461
1462 /* gnttab_end_foreign_access() needs a page ref until
1463 * foreign access is ended (which may be deferred).
1464 */
1465 get_page(page);
1466 gnttab_end_foreign_access(ref, page);
1467 queue->grant_rx_ref[id] = INVALID_GRANT_REF;
1468
1469 kfree_skb(skb);
1470 }
1471
1472 spin_unlock_bh(&queue->rx_lock);
1473}
1474
1475static netdev_features_t xennet_fix_features(struct net_device *dev,
1476 netdev_features_t features)
1477{
1478 struct netfront_info *np = netdev_priv(dev);
1479
1480 if (features & NETIF_F_SG &&
1481 !xenbus_read_unsigned(np->xbdev->otherend, "feature-sg", 0))
1482 features &= ~NETIF_F_SG;
1483
1484 if (features & NETIF_F_IPV6_CSUM &&
1485 !xenbus_read_unsigned(np->xbdev->otherend,
1486 "feature-ipv6-csum-offload", 0))
1487 features &= ~NETIF_F_IPV6_CSUM;
1488
1489 if (features & NETIF_F_TSO &&
1490 !xenbus_read_unsigned(np->xbdev->otherend, "feature-gso-tcpv4", 0))
1491 features &= ~NETIF_F_TSO;
1492
1493 if (features & NETIF_F_TSO6 &&
1494 !xenbus_read_unsigned(np->xbdev->otherend, "feature-gso-tcpv6", 0))
1495 features &= ~NETIF_F_TSO6;
1496
1497 return features;
1498}
1499
1500static int xennet_set_features(struct net_device *dev,
1501 netdev_features_t features)
1502{
1503 if (!(features & NETIF_F_SG) && dev->mtu > ETH_DATA_LEN) {
1504 netdev_info(dev, "Reducing MTU because no SG offload");
1505 dev->mtu = ETH_DATA_LEN;
1506 }
1507
1508 return 0;
1509}
1510
1511static bool xennet_handle_tx(struct netfront_queue *queue, unsigned int *eoi)
1512{
1513 unsigned long flags;
1514
1515 if (unlikely(queue->info->broken))
1516 return false;
1517
1518 spin_lock_irqsave(&queue->tx_lock, flags);
1519 if (xennet_tx_buf_gc(queue))
1520 *eoi = 0;
1521 spin_unlock_irqrestore(&queue->tx_lock, flags);
1522
1523 return true;
1524}
1525
1526static irqreturn_t xennet_tx_interrupt(int irq, void *dev_id)
1527{
1528 unsigned int eoiflag = XEN_EOI_FLAG_SPURIOUS;
1529
1530 if (likely(xennet_handle_tx(dev_id, &eoiflag)))
1531 xen_irq_lateeoi(irq, eoiflag);
1532
1533 return IRQ_HANDLED;
1534}
1535
1536static bool xennet_handle_rx(struct netfront_queue *queue, unsigned int *eoi)
1537{
1538 unsigned int work_queued;
1539 unsigned long flags;
1540
1541 if (unlikely(queue->info->broken))
1542 return false;
1543
1544 spin_lock_irqsave(&queue->rx_cons_lock, flags);
1545 work_queued = XEN_RING_NR_UNCONSUMED_RESPONSES(&queue->rx);
1546 if (work_queued > queue->rx_rsp_unconsumed) {
1547 queue->rx_rsp_unconsumed = work_queued;
1548 *eoi = 0;
1549 } else if (unlikely(work_queued < queue->rx_rsp_unconsumed)) {
1550 const struct device *dev = &queue->info->netdev->dev;
1551
1552 spin_unlock_irqrestore(&queue->rx_cons_lock, flags);
1553 dev_alert(dev, "RX producer index going backwards\n");
1554 dev_alert(dev, "Disabled for further use\n");
1555 queue->info->broken = true;
1556 return false;
1557 }
1558 spin_unlock_irqrestore(&queue->rx_cons_lock, flags);
1559
1560 if (likely(netif_carrier_ok(queue->info->netdev) && work_queued))
1561 napi_schedule(&queue->napi);
1562
1563 return true;
1564}
1565
1566static irqreturn_t xennet_rx_interrupt(int irq, void *dev_id)
1567{
1568 unsigned int eoiflag = XEN_EOI_FLAG_SPURIOUS;
1569
1570 if (likely(xennet_handle_rx(dev_id, &eoiflag)))
1571 xen_irq_lateeoi(irq, eoiflag);
1572
1573 return IRQ_HANDLED;
1574}
1575
1576static irqreturn_t xennet_interrupt(int irq, void *dev_id)
1577{
1578 unsigned int eoiflag = XEN_EOI_FLAG_SPURIOUS;
1579
1580 if (xennet_handle_tx(dev_id, &eoiflag) &&
1581 xennet_handle_rx(dev_id, &eoiflag))
1582 xen_irq_lateeoi(irq, eoiflag);
1583
1584 return IRQ_HANDLED;
1585}
1586
1587#ifdef CONFIG_NET_POLL_CONTROLLER
1588static void xennet_poll_controller(struct net_device *dev)
1589{
1590 /* Poll each queue */
1591 struct netfront_info *info = netdev_priv(dev);
1592 unsigned int num_queues = dev->real_num_tx_queues;
1593 unsigned int i;
1594
1595 if (info->broken)
1596 return;
1597
1598 for (i = 0; i < num_queues; ++i)
1599 xennet_interrupt(0, &info->queues[i]);
1600}
1601#endif
1602
1603#define NETBACK_XDP_HEADROOM_DISABLE 0
1604#define NETBACK_XDP_HEADROOM_ENABLE 1
1605
1606static int talk_to_netback_xdp(struct netfront_info *np, int xdp)
1607{
1608 int err;
1609 unsigned short headroom;
1610
1611 headroom = xdp ? XDP_PACKET_HEADROOM : 0;
1612 err = xenbus_printf(XBT_NIL, np->xbdev->nodename,
1613 "xdp-headroom", "%hu",
1614 headroom);
1615 if (err)
1616 pr_warn("Error writing xdp-headroom\n");
1617
1618 return err;
1619}
1620
1621static int xennet_xdp_set(struct net_device *dev, struct bpf_prog *prog,
1622 struct netlink_ext_ack *extack)
1623{
1624 unsigned long max_mtu = XEN_PAGE_SIZE - XDP_PACKET_HEADROOM;
1625 struct netfront_info *np = netdev_priv(dev);
1626 struct bpf_prog *old_prog;
1627 unsigned int i, err;
1628
1629 if (dev->mtu > max_mtu) {
1630 netdev_warn(dev, "XDP requires MTU less than %lu\n", max_mtu);
1631 return -EINVAL;
1632 }
1633
1634 if (!np->netback_has_xdp_headroom)
1635 return 0;
1636
1637 xenbus_switch_state(np->xbdev, XenbusStateReconfiguring);
1638
1639 err = talk_to_netback_xdp(np, prog ? NETBACK_XDP_HEADROOM_ENABLE :
1640 NETBACK_XDP_HEADROOM_DISABLE);
1641 if (err)
1642 return err;
1643
1644 /* avoid the race with XDP headroom adjustment */
1645 wait_event(module_wq,
1646 xenbus_read_driver_state(np->xbdev->otherend) ==
1647 XenbusStateReconfigured);
1648 np->netfront_xdp_enabled = true;
1649
1650 old_prog = rtnl_dereference(np->queues[0].xdp_prog);
1651
1652 if (prog)
1653 bpf_prog_add(prog, dev->real_num_tx_queues);
1654
1655 for (i = 0; i < dev->real_num_tx_queues; ++i)
1656 rcu_assign_pointer(np->queues[i].xdp_prog, prog);
1657
1658 if (old_prog)
1659 for (i = 0; i < dev->real_num_tx_queues; ++i)
1660 bpf_prog_put(old_prog);
1661
1662 xenbus_switch_state(np->xbdev, XenbusStateConnected);
1663
1664 return 0;
1665}
1666
1667static int xennet_xdp(struct net_device *dev, struct netdev_bpf *xdp)
1668{
1669 struct netfront_info *np = netdev_priv(dev);
1670
1671 if (np->broken)
1672 return -ENODEV;
1673
1674 switch (xdp->command) {
1675 case XDP_SETUP_PROG:
1676 return xennet_xdp_set(dev, xdp->prog, xdp->extack);
1677 default:
1678 return -EINVAL;
1679 }
1680}
1681
1682static const struct net_device_ops xennet_netdev_ops = {
1683 .ndo_uninit = xennet_uninit,
1684 .ndo_open = xennet_open,
1685 .ndo_stop = xennet_close,
1686 .ndo_start_xmit = xennet_start_xmit,
1687 .ndo_change_mtu = xennet_change_mtu,
1688 .ndo_get_stats64 = xennet_get_stats64,
1689 .ndo_set_mac_address = eth_mac_addr,
1690 .ndo_validate_addr = eth_validate_addr,
1691 .ndo_fix_features = xennet_fix_features,
1692 .ndo_set_features = xennet_set_features,
1693 .ndo_select_queue = xennet_select_queue,
1694 .ndo_bpf = xennet_xdp,
1695 .ndo_xdp_xmit = xennet_xdp_xmit,
1696#ifdef CONFIG_NET_POLL_CONTROLLER
1697 .ndo_poll_controller = xennet_poll_controller,
1698#endif
1699};
1700
1701static void xennet_free_netdev(struct net_device *netdev)
1702{
1703 struct netfront_info *np = netdev_priv(netdev);
1704
1705 free_percpu(np->rx_stats);
1706 free_percpu(np->tx_stats);
1707 free_netdev(netdev);
1708}
1709
1710static struct net_device *xennet_create_dev(struct xenbus_device *dev)
1711{
1712 int err;
1713 struct net_device *netdev;
1714 struct netfront_info *np;
1715
1716 netdev = alloc_etherdev_mq(sizeof(struct netfront_info), xennet_max_queues);
1717 if (!netdev)
1718 return ERR_PTR(-ENOMEM);
1719
1720 np = netdev_priv(netdev);
1721 np->xbdev = dev;
1722
1723 np->queues = NULL;
1724
1725 err = -ENOMEM;
1726 np->rx_stats = netdev_alloc_pcpu_stats(struct netfront_stats);
1727 if (np->rx_stats == NULL)
1728 goto exit;
1729 np->tx_stats = netdev_alloc_pcpu_stats(struct netfront_stats);
1730 if (np->tx_stats == NULL)
1731 goto exit;
1732
1733 netdev->netdev_ops = &xennet_netdev_ops;
1734
1735 netdev->features = NETIF_F_IP_CSUM | NETIF_F_RXCSUM |
1736 NETIF_F_GSO_ROBUST;
1737 netdev->hw_features = NETIF_F_SG |
1738 NETIF_F_IPV6_CSUM |
1739 NETIF_F_TSO | NETIF_F_TSO6;
1740
1741 /*
1742 * Assume that all hw features are available for now. This set
1743 * will be adjusted by the call to netdev_update_features() in
1744 * xennet_connect() which is the earliest point where we can
1745 * negotiate with the backend regarding supported features.
1746 */
1747 netdev->features |= netdev->hw_features;
1748 netdev->xdp_features = NETDEV_XDP_ACT_BASIC | NETDEV_XDP_ACT_REDIRECT |
1749 NETDEV_XDP_ACT_NDO_XMIT;
1750
1751 netdev->ethtool_ops = &xennet_ethtool_ops;
1752 netdev->min_mtu = ETH_MIN_MTU;
1753 netdev->max_mtu = XEN_NETIF_MAX_TX_SIZE;
1754 SET_NETDEV_DEV(netdev, &dev->dev);
1755
1756 np->netdev = netdev;
1757 np->netfront_xdp_enabled = false;
1758
1759 netif_carrier_off(netdev);
1760
1761 do {
1762 xenbus_switch_state(dev, XenbusStateInitialising);
1763 err = wait_event_timeout(module_wq,
1764 xenbus_read_driver_state(dev->otherend) !=
1765 XenbusStateClosed &&
1766 xenbus_read_driver_state(dev->otherend) !=
1767 XenbusStateUnknown, XENNET_TIMEOUT);
1768 } while (!err);
1769
1770 return netdev;
1771
1772 exit:
1773 xennet_free_netdev(netdev);
1774 return ERR_PTR(err);
1775}
1776
1777/*
1778 * Entry point to this code when a new device is created. Allocate the basic
1779 * structures and the ring buffers for communication with the backend, and
1780 * inform the backend of the appropriate details for those.
1781 */
1782static int netfront_probe(struct xenbus_device *dev,
1783 const struct xenbus_device_id *id)
1784{
1785 int err;
1786 struct net_device *netdev;
1787 struct netfront_info *info;
1788
1789 netdev = xennet_create_dev(dev);
1790 if (IS_ERR(netdev)) {
1791 err = PTR_ERR(netdev);
1792 xenbus_dev_fatal(dev, err, "creating netdev");
1793 return err;
1794 }
1795
1796 info = netdev_priv(netdev);
1797 dev_set_drvdata(&dev->dev, info);
1798#ifdef CONFIG_SYSFS
1799 info->netdev->sysfs_groups[0] = &xennet_dev_group;
1800#endif
1801
1802 return 0;
1803}
1804
1805static void xennet_end_access(int ref, void *page)
1806{
1807 /* This frees the page as a side-effect */
1808 if (ref != INVALID_GRANT_REF)
1809 gnttab_end_foreign_access(ref, virt_to_page(page));
1810}
1811
1812static void xennet_disconnect_backend(struct netfront_info *info)
1813{
1814 unsigned int i = 0;
1815 unsigned int num_queues = info->netdev->real_num_tx_queues;
1816
1817 netif_carrier_off(info->netdev);
1818
1819 for (i = 0; i < num_queues && info->queues; ++i) {
1820 struct netfront_queue *queue = &info->queues[i];
1821
1822 del_timer_sync(&queue->rx_refill_timer);
1823
1824 if (queue->tx_irq && (queue->tx_irq == queue->rx_irq))
1825 unbind_from_irqhandler(queue->tx_irq, queue);
1826 if (queue->tx_irq && (queue->tx_irq != queue->rx_irq)) {
1827 unbind_from_irqhandler(queue->tx_irq, queue);
1828 unbind_from_irqhandler(queue->rx_irq, queue);
1829 }
1830 queue->tx_evtchn = queue->rx_evtchn = 0;
1831 queue->tx_irq = queue->rx_irq = 0;
1832
1833 if (netif_running(info->netdev))
1834 napi_synchronize(&queue->napi);
1835
1836 xennet_release_tx_bufs(queue);
1837 xennet_release_rx_bufs(queue);
1838 gnttab_free_grant_references(queue->gref_tx_head);
1839 gnttab_free_grant_references(queue->gref_rx_head);
1840
1841 /* End access and free the pages */
1842 xennet_end_access(queue->tx_ring_ref, queue->tx.sring);
1843 xennet_end_access(queue->rx_ring_ref, queue->rx.sring);
1844
1845 queue->tx_ring_ref = INVALID_GRANT_REF;
1846 queue->rx_ring_ref = INVALID_GRANT_REF;
1847 queue->tx.sring = NULL;
1848 queue->rx.sring = NULL;
1849
1850 page_pool_destroy(queue->page_pool);
1851 }
1852}
1853
1854/*
1855 * We are reconnecting to the backend, due to a suspend/resume, or a backend
1856 * driver restart. We tear down our netif structure and recreate it, but
1857 * leave the device-layer structures intact so that this is transparent to the
1858 * rest of the kernel.
1859 */
1860static int netfront_resume(struct xenbus_device *dev)
1861{
1862 struct netfront_info *info = dev_get_drvdata(&dev->dev);
1863
1864 dev_dbg(&dev->dev, "%s\n", dev->nodename);
1865
1866 netif_tx_lock_bh(info->netdev);
1867 netif_device_detach(info->netdev);
1868 netif_tx_unlock_bh(info->netdev);
1869
1870 xennet_disconnect_backend(info);
1871
1872 rtnl_lock();
1873 if (info->queues)
1874 xennet_destroy_queues(info);
1875 rtnl_unlock();
1876
1877 return 0;
1878}
1879
1880static int xen_net_read_mac(struct xenbus_device *dev, u8 mac[])
1881{
1882 char *s, *e, *macstr;
1883 int i;
1884
1885 macstr = s = xenbus_read(XBT_NIL, dev->nodename, "mac", NULL);
1886 if (IS_ERR(macstr))
1887 return PTR_ERR(macstr);
1888
1889 for (i = 0; i < ETH_ALEN; i++) {
1890 mac[i] = simple_strtoul(s, &e, 16);
1891 if ((s == e) || (*e != ((i == ETH_ALEN-1) ? '\0' : ':'))) {
1892 kfree(macstr);
1893 return -ENOENT;
1894 }
1895 s = e+1;
1896 }
1897
1898 kfree(macstr);
1899 return 0;
1900}
1901
1902static int setup_netfront_single(struct netfront_queue *queue)
1903{
1904 int err;
1905
1906 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->tx_evtchn);
1907 if (err < 0)
1908 goto fail;
1909
1910 err = bind_evtchn_to_irqhandler_lateeoi(queue->tx_evtchn,
1911 xennet_interrupt, 0,
1912 queue->info->netdev->name,
1913 queue);
1914 if (err < 0)
1915 goto bind_fail;
1916 queue->rx_evtchn = queue->tx_evtchn;
1917 queue->rx_irq = queue->tx_irq = err;
1918
1919 return 0;
1920
1921bind_fail:
1922 xenbus_free_evtchn(queue->info->xbdev, queue->tx_evtchn);
1923 queue->tx_evtchn = 0;
1924fail:
1925 return err;
1926}
1927
1928static int setup_netfront_split(struct netfront_queue *queue)
1929{
1930 int err;
1931
1932 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->tx_evtchn);
1933 if (err < 0)
1934 goto fail;
1935 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->rx_evtchn);
1936 if (err < 0)
1937 goto alloc_rx_evtchn_fail;
1938
1939 snprintf(queue->tx_irq_name, sizeof(queue->tx_irq_name),
1940 "%s-tx", queue->name);
1941 err = bind_evtchn_to_irqhandler_lateeoi(queue->tx_evtchn,
1942 xennet_tx_interrupt, 0,
1943 queue->tx_irq_name, queue);
1944 if (err < 0)
1945 goto bind_tx_fail;
1946 queue->tx_irq = err;
1947
1948 snprintf(queue->rx_irq_name, sizeof(queue->rx_irq_name),
1949 "%s-rx", queue->name);
1950 err = bind_evtchn_to_irqhandler_lateeoi(queue->rx_evtchn,
1951 xennet_rx_interrupt, 0,
1952 queue->rx_irq_name, queue);
1953 if (err < 0)
1954 goto bind_rx_fail;
1955 queue->rx_irq = err;
1956
1957 return 0;
1958
1959bind_rx_fail:
1960 unbind_from_irqhandler(queue->tx_irq, queue);
1961 queue->tx_irq = 0;
1962bind_tx_fail:
1963 xenbus_free_evtchn(queue->info->xbdev, queue->rx_evtchn);
1964 queue->rx_evtchn = 0;
1965alloc_rx_evtchn_fail:
1966 xenbus_free_evtchn(queue->info->xbdev, queue->tx_evtchn);
1967 queue->tx_evtchn = 0;
1968fail:
1969 return err;
1970}
1971
1972static int setup_netfront(struct xenbus_device *dev,
1973 struct netfront_queue *queue, unsigned int feature_split_evtchn)
1974{
1975 struct xen_netif_tx_sring *txs;
1976 struct xen_netif_rx_sring *rxs;
1977 int err;
1978
1979 queue->tx_ring_ref = INVALID_GRANT_REF;
1980 queue->rx_ring_ref = INVALID_GRANT_REF;
1981 queue->rx.sring = NULL;
1982 queue->tx.sring = NULL;
1983
1984 err = xenbus_setup_ring(dev, GFP_NOIO | __GFP_HIGH, (void **)&txs,
1985 1, &queue->tx_ring_ref);
1986 if (err)
1987 goto fail;
1988
1989 XEN_FRONT_RING_INIT(&queue->tx, txs, XEN_PAGE_SIZE);
1990
1991 err = xenbus_setup_ring(dev, GFP_NOIO | __GFP_HIGH, (void **)&rxs,
1992 1, &queue->rx_ring_ref);
1993 if (err)
1994 goto fail;
1995
1996 XEN_FRONT_RING_INIT(&queue->rx, rxs, XEN_PAGE_SIZE);
1997
1998 if (feature_split_evtchn)
1999 err = setup_netfront_split(queue);
2000 /* setup single event channel if
2001 * a) feature-split-event-channels == 0
2002 * b) feature-split-event-channels == 1 but failed to setup
2003 */
2004 if (!feature_split_evtchn || err)
2005 err = setup_netfront_single(queue);
2006
2007 if (err)
2008 goto fail;
2009
2010 return 0;
2011
2012 fail:
2013 xenbus_teardown_ring((void **)&queue->rx.sring, 1, &queue->rx_ring_ref);
2014 xenbus_teardown_ring((void **)&queue->tx.sring, 1, &queue->tx_ring_ref);
2015
2016 return err;
2017}
2018
2019/* Queue-specific initialisation
2020 * This used to be done in xennet_create_dev() but must now
2021 * be run per-queue.
2022 */
2023static int xennet_init_queue(struct netfront_queue *queue)
2024{
2025 unsigned short i;
2026 int err = 0;
2027 char *devid;
2028
2029 spin_lock_init(&queue->tx_lock);
2030 spin_lock_init(&queue->rx_lock);
2031 spin_lock_init(&queue->rx_cons_lock);
2032
2033 timer_setup(&queue->rx_refill_timer, rx_refill_timeout, 0);
2034
2035 devid = strrchr(queue->info->xbdev->nodename, '/') + 1;
2036 snprintf(queue->name, sizeof(queue->name), "vif%s-q%u",
2037 devid, queue->id);
2038
2039 /* Initialise tx_skb_freelist as a free chain containing every entry. */
2040 queue->tx_skb_freelist = 0;
2041 queue->tx_pend_queue = TX_LINK_NONE;
2042 for (i = 0; i < NET_TX_RING_SIZE; i++) {
2043 queue->tx_link[i] = i + 1;
2044 queue->grant_tx_ref[i] = INVALID_GRANT_REF;
2045 queue->grant_tx_page[i] = NULL;
2046 }
2047 queue->tx_link[NET_TX_RING_SIZE - 1] = TX_LINK_NONE;
2048
2049 /* Clear out rx_skbs */
2050 for (i = 0; i < NET_RX_RING_SIZE; i++) {
2051 queue->rx_skbs[i] = NULL;
2052 queue->grant_rx_ref[i] = INVALID_GRANT_REF;
2053 }
2054
2055 /* A grant for every tx ring slot */
2056 if (gnttab_alloc_grant_references(NET_TX_RING_SIZE,
2057 &queue->gref_tx_head) < 0) {
2058 pr_alert("can't alloc tx grant refs\n");
2059 err = -ENOMEM;
2060 goto exit;
2061 }
2062
2063 /* A grant for every rx ring slot */
2064 if (gnttab_alloc_grant_references(NET_RX_RING_SIZE,
2065 &queue->gref_rx_head) < 0) {
2066 pr_alert("can't alloc rx grant refs\n");
2067 err = -ENOMEM;
2068 goto exit_free_tx;
2069 }
2070
2071 return 0;
2072
2073 exit_free_tx:
2074 gnttab_free_grant_references(queue->gref_tx_head);
2075 exit:
2076 return err;
2077}
2078
2079static int write_queue_xenstore_keys(struct netfront_queue *queue,
2080 struct xenbus_transaction *xbt, int write_hierarchical)
2081{
2082 /* Write the queue-specific keys into XenStore in the traditional
2083 * way for a single queue, or in a queue subkeys for multiple
2084 * queues.
2085 */
2086 struct xenbus_device *dev = queue->info->xbdev;
2087 int err;
2088 const char *message;
2089 char *path;
2090 size_t pathsize;
2091
2092 /* Choose the correct place to write the keys */
2093 if (write_hierarchical) {
2094 pathsize = strlen(dev->nodename) + 10;
2095 path = kzalloc(pathsize, GFP_KERNEL);
2096 if (!path) {
2097 err = -ENOMEM;
2098 message = "out of memory while writing ring references";
2099 goto error;
2100 }
2101 snprintf(path, pathsize, "%s/queue-%u",
2102 dev->nodename, queue->id);
2103 } else {
2104 path = (char *)dev->nodename;
2105 }
2106
2107 /* Write ring references */
2108 err = xenbus_printf(*xbt, path, "tx-ring-ref", "%u",
2109 queue->tx_ring_ref);
2110 if (err) {
2111 message = "writing tx-ring-ref";
2112 goto error;
2113 }
2114
2115 err = xenbus_printf(*xbt, path, "rx-ring-ref", "%u",
2116 queue->rx_ring_ref);
2117 if (err) {
2118 message = "writing rx-ring-ref";
2119 goto error;
2120 }
2121
2122 /* Write event channels; taking into account both shared
2123 * and split event channel scenarios.
2124 */
2125 if (queue->tx_evtchn == queue->rx_evtchn) {
2126 /* Shared event channel */
2127 err = xenbus_printf(*xbt, path,
2128 "event-channel", "%u", queue->tx_evtchn);
2129 if (err) {
2130 message = "writing event-channel";
2131 goto error;
2132 }
2133 } else {
2134 /* Split event channels */
2135 err = xenbus_printf(*xbt, path,
2136 "event-channel-tx", "%u", queue->tx_evtchn);
2137 if (err) {
2138 message = "writing event-channel-tx";
2139 goto error;
2140 }
2141
2142 err = xenbus_printf(*xbt, path,
2143 "event-channel-rx", "%u", queue->rx_evtchn);
2144 if (err) {
2145 message = "writing event-channel-rx";
2146 goto error;
2147 }
2148 }
2149
2150 if (write_hierarchical)
2151 kfree(path);
2152 return 0;
2153
2154error:
2155 if (write_hierarchical)
2156 kfree(path);
2157 xenbus_dev_fatal(dev, err, "%s", message);
2158 return err;
2159}
2160
2161
2162
2163static int xennet_create_page_pool(struct netfront_queue *queue)
2164{
2165 int err;
2166 struct page_pool_params pp_params = {
2167 .order = 0,
2168 .flags = 0,
2169 .pool_size = NET_RX_RING_SIZE,
2170 .nid = NUMA_NO_NODE,
2171 .dev = &queue->info->netdev->dev,
2172 .offset = XDP_PACKET_HEADROOM,
2173 .max_len = XEN_PAGE_SIZE - XDP_PACKET_HEADROOM,
2174 };
2175
2176 queue->page_pool = page_pool_create(&pp_params);
2177 if (IS_ERR(queue->page_pool)) {
2178 err = PTR_ERR(queue->page_pool);
2179 queue->page_pool = NULL;
2180 return err;
2181 }
2182
2183 err = xdp_rxq_info_reg(&queue->xdp_rxq, queue->info->netdev,
2184 queue->id, 0);
2185 if (err) {
2186 netdev_err(queue->info->netdev, "xdp_rxq_info_reg failed\n");
2187 goto err_free_pp;
2188 }
2189
2190 err = xdp_rxq_info_reg_mem_model(&queue->xdp_rxq,
2191 MEM_TYPE_PAGE_POOL, queue->page_pool);
2192 if (err) {
2193 netdev_err(queue->info->netdev, "xdp_rxq_info_reg_mem_model failed\n");
2194 goto err_unregister_rxq;
2195 }
2196 return 0;
2197
2198err_unregister_rxq:
2199 xdp_rxq_info_unreg(&queue->xdp_rxq);
2200err_free_pp:
2201 page_pool_destroy(queue->page_pool);
2202 queue->page_pool = NULL;
2203 return err;
2204}
2205
2206static int xennet_create_queues(struct netfront_info *info,
2207 unsigned int *num_queues)
2208{
2209 unsigned int i;
2210 int ret;
2211
2212 info->queues = kcalloc(*num_queues, sizeof(struct netfront_queue),
2213 GFP_KERNEL);
2214 if (!info->queues)
2215 return -ENOMEM;
2216
2217 for (i = 0; i < *num_queues; i++) {
2218 struct netfront_queue *queue = &info->queues[i];
2219
2220 queue->id = i;
2221 queue->info = info;
2222
2223 ret = xennet_init_queue(queue);
2224 if (ret < 0) {
2225 dev_warn(&info->xbdev->dev,
2226 "only created %d queues\n", i);
2227 *num_queues = i;
2228 break;
2229 }
2230
2231 /* use page pool recycling instead of buddy allocator */
2232 ret = xennet_create_page_pool(queue);
2233 if (ret < 0) {
2234 dev_err(&info->xbdev->dev, "can't allocate page pool\n");
2235 *num_queues = i;
2236 return ret;
2237 }
2238
2239 netif_napi_add(queue->info->netdev, &queue->napi, xennet_poll);
2240 if (netif_running(info->netdev))
2241 napi_enable(&queue->napi);
2242 }
2243
2244 netif_set_real_num_tx_queues(info->netdev, *num_queues);
2245
2246 if (*num_queues == 0) {
2247 dev_err(&info->xbdev->dev, "no queues\n");
2248 return -EINVAL;
2249 }
2250 return 0;
2251}
2252
2253/* Common code used when first setting up, and when resuming. */
2254static int talk_to_netback(struct xenbus_device *dev,
2255 struct netfront_info *info)
2256{
2257 const char *message;
2258 struct xenbus_transaction xbt;
2259 int err;
2260 unsigned int feature_split_evtchn;
2261 unsigned int i = 0;
2262 unsigned int max_queues = 0;
2263 struct netfront_queue *queue = NULL;
2264 unsigned int num_queues = 1;
2265 u8 addr[ETH_ALEN];
2266
2267 info->netdev->irq = 0;
2268
2269 /* Check if backend is trusted. */
2270 info->bounce = !xennet_trusted ||
2271 !xenbus_read_unsigned(dev->nodename, "trusted", 1);
2272
2273 /* Check if backend supports multiple queues */
2274 max_queues = xenbus_read_unsigned(info->xbdev->otherend,
2275 "multi-queue-max-queues", 1);
2276 num_queues = min(max_queues, xennet_max_queues);
2277
2278 /* Check feature-split-event-channels */
2279 feature_split_evtchn = xenbus_read_unsigned(info->xbdev->otherend,
2280 "feature-split-event-channels", 0);
2281
2282 /* Read mac addr. */
2283 err = xen_net_read_mac(dev, addr);
2284 if (err) {
2285 xenbus_dev_fatal(dev, err, "parsing %s/mac", dev->nodename);
2286 goto out_unlocked;
2287 }
2288 eth_hw_addr_set(info->netdev, addr);
2289
2290 info->netback_has_xdp_headroom = xenbus_read_unsigned(info->xbdev->otherend,
2291 "feature-xdp-headroom", 0);
2292 if (info->netback_has_xdp_headroom) {
2293 /* set the current xen-netfront xdp state */
2294 err = talk_to_netback_xdp(info, info->netfront_xdp_enabled ?
2295 NETBACK_XDP_HEADROOM_ENABLE :
2296 NETBACK_XDP_HEADROOM_DISABLE);
2297 if (err)
2298 goto out_unlocked;
2299 }
2300
2301 rtnl_lock();
2302 if (info->queues)
2303 xennet_destroy_queues(info);
2304
2305 /* For the case of a reconnect reset the "broken" indicator. */
2306 info->broken = false;
2307
2308 err = xennet_create_queues(info, &num_queues);
2309 if (err < 0) {
2310 xenbus_dev_fatal(dev, err, "creating queues");
2311 kfree(info->queues);
2312 info->queues = NULL;
2313 goto out;
2314 }
2315 rtnl_unlock();
2316
2317 /* Create shared ring, alloc event channel -- for each queue */
2318 for (i = 0; i < num_queues; ++i) {
2319 queue = &info->queues[i];
2320 err = setup_netfront(dev, queue, feature_split_evtchn);
2321 if (err)
2322 goto destroy_ring;
2323 }
2324
2325again:
2326 err = xenbus_transaction_start(&xbt);
2327 if (err) {
2328 xenbus_dev_fatal(dev, err, "starting transaction");
2329 goto destroy_ring;
2330 }
2331
2332 if (xenbus_exists(XBT_NIL,
2333 info->xbdev->otherend, "multi-queue-max-queues")) {
2334 /* Write the number of queues */
2335 err = xenbus_printf(xbt, dev->nodename,
2336 "multi-queue-num-queues", "%u", num_queues);
2337 if (err) {
2338 message = "writing multi-queue-num-queues";
2339 goto abort_transaction_no_dev_fatal;
2340 }
2341 }
2342
2343 if (num_queues == 1) {
2344 err = write_queue_xenstore_keys(&info->queues[0], &xbt, 0); /* flat */
2345 if (err)
2346 goto abort_transaction_no_dev_fatal;
2347 } else {
2348 /* Write the keys for each queue */
2349 for (i = 0; i < num_queues; ++i) {
2350 queue = &info->queues[i];
2351 err = write_queue_xenstore_keys(queue, &xbt, 1); /* hierarchical */
2352 if (err)
2353 goto abort_transaction_no_dev_fatal;
2354 }
2355 }
2356
2357 /* The remaining keys are not queue-specific */
2358 err = xenbus_printf(xbt, dev->nodename, "request-rx-copy", "%u",
2359 1);
2360 if (err) {
2361 message = "writing request-rx-copy";
2362 goto abort_transaction;
2363 }
2364
2365 err = xenbus_printf(xbt, dev->nodename, "feature-rx-notify", "%d", 1);
2366 if (err) {
2367 message = "writing feature-rx-notify";
2368 goto abort_transaction;
2369 }
2370
2371 err = xenbus_printf(xbt, dev->nodename, "feature-sg", "%d", 1);
2372 if (err) {
2373 message = "writing feature-sg";
2374 goto abort_transaction;
2375 }
2376
2377 err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv4", "%d", 1);
2378 if (err) {
2379 message = "writing feature-gso-tcpv4";
2380 goto abort_transaction;
2381 }
2382
2383 err = xenbus_write(xbt, dev->nodename, "feature-gso-tcpv6", "1");
2384 if (err) {
2385 message = "writing feature-gso-tcpv6";
2386 goto abort_transaction;
2387 }
2388
2389 err = xenbus_write(xbt, dev->nodename, "feature-ipv6-csum-offload",
2390 "1");
2391 if (err) {
2392 message = "writing feature-ipv6-csum-offload";
2393 goto abort_transaction;
2394 }
2395
2396 err = xenbus_transaction_end(xbt, 0);
2397 if (err) {
2398 if (err == -EAGAIN)
2399 goto again;
2400 xenbus_dev_fatal(dev, err, "completing transaction");
2401 goto destroy_ring;
2402 }
2403
2404 return 0;
2405
2406 abort_transaction:
2407 xenbus_dev_fatal(dev, err, "%s", message);
2408abort_transaction_no_dev_fatal:
2409 xenbus_transaction_end(xbt, 1);
2410 destroy_ring:
2411 xennet_disconnect_backend(info);
2412 rtnl_lock();
2413 xennet_destroy_queues(info);
2414 out:
2415 rtnl_unlock();
2416out_unlocked:
2417 device_unregister(&dev->dev);
2418 return err;
2419}
2420
2421static int xennet_connect(struct net_device *dev)
2422{
2423 struct netfront_info *np = netdev_priv(dev);
2424 unsigned int num_queues = 0;
2425 int err;
2426 unsigned int j = 0;
2427 struct netfront_queue *queue = NULL;
2428
2429 if (!xenbus_read_unsigned(np->xbdev->otherend, "feature-rx-copy", 0)) {
2430 dev_info(&dev->dev,
2431 "backend does not support copying receive path\n");
2432 return -ENODEV;
2433 }
2434
2435 err = talk_to_netback(np->xbdev, np);
2436 if (err)
2437 return err;
2438 if (np->netback_has_xdp_headroom)
2439 pr_info("backend supports XDP headroom\n");
2440 if (np->bounce)
2441 dev_info(&np->xbdev->dev,
2442 "bouncing transmitted data to zeroed pages\n");
2443
2444 /* talk_to_netback() sets the correct number of queues */
2445 num_queues = dev->real_num_tx_queues;
2446
2447 if (dev->reg_state == NETREG_UNINITIALIZED) {
2448 err = register_netdev(dev);
2449 if (err) {
2450 pr_warn("%s: register_netdev err=%d\n", __func__, err);
2451 device_unregister(&np->xbdev->dev);
2452 return err;
2453 }
2454 }
2455
2456 rtnl_lock();
2457 netdev_update_features(dev);
2458 rtnl_unlock();
2459
2460 /*
2461 * All public and private state should now be sane. Get
2462 * ready to start sending and receiving packets and give the driver
2463 * domain a kick because we've probably just requeued some
2464 * packets.
2465 */
2466 netif_tx_lock_bh(np->netdev);
2467 netif_device_attach(np->netdev);
2468 netif_tx_unlock_bh(np->netdev);
2469
2470 netif_carrier_on(np->netdev);
2471 for (j = 0; j < num_queues; ++j) {
2472 queue = &np->queues[j];
2473
2474 notify_remote_via_irq(queue->tx_irq);
2475 if (queue->tx_irq != queue->rx_irq)
2476 notify_remote_via_irq(queue->rx_irq);
2477
2478 spin_lock_bh(&queue->rx_lock);
2479 xennet_alloc_rx_buffers(queue);
2480 spin_unlock_bh(&queue->rx_lock);
2481 }
2482
2483 return 0;
2484}
2485
2486/*
2487 * Callback received when the backend's state changes.
2488 */
2489static void netback_changed(struct xenbus_device *dev,
2490 enum xenbus_state backend_state)
2491{
2492 struct netfront_info *np = dev_get_drvdata(&dev->dev);
2493 struct net_device *netdev = np->netdev;
2494
2495 dev_dbg(&dev->dev, "%s\n", xenbus_strstate(backend_state));
2496
2497 wake_up_all(&module_wq);
2498
2499 switch (backend_state) {
2500 case XenbusStateInitialising:
2501 case XenbusStateInitialised:
2502 case XenbusStateReconfiguring:
2503 case XenbusStateReconfigured:
2504 case XenbusStateUnknown:
2505 break;
2506
2507 case XenbusStateInitWait:
2508 if (dev->state != XenbusStateInitialising)
2509 break;
2510 if (xennet_connect(netdev) != 0)
2511 break;
2512 xenbus_switch_state(dev, XenbusStateConnected);
2513 break;
2514
2515 case XenbusStateConnected:
2516 netdev_notify_peers(netdev);
2517 break;
2518
2519 case XenbusStateClosed:
2520 if (dev->state == XenbusStateClosed)
2521 break;
2522 fallthrough; /* Missed the backend's CLOSING state */
2523 case XenbusStateClosing:
2524 xenbus_frontend_closed(dev);
2525 break;
2526 }
2527}
2528
2529static const struct xennet_stat {
2530 char name[ETH_GSTRING_LEN];
2531 u16 offset;
2532} xennet_stats[] = {
2533 {
2534 "rx_gso_checksum_fixup",
2535 offsetof(struct netfront_info, rx_gso_checksum_fixup)
2536 },
2537};
2538
2539static int xennet_get_sset_count(struct net_device *dev, int string_set)
2540{
2541 switch (string_set) {
2542 case ETH_SS_STATS:
2543 return ARRAY_SIZE(xennet_stats);
2544 default:
2545 return -EINVAL;
2546 }
2547}
2548
2549static void xennet_get_ethtool_stats(struct net_device *dev,
2550 struct ethtool_stats *stats, u64 * data)
2551{
2552 void *np = netdev_priv(dev);
2553 int i;
2554
2555 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++)
2556 data[i] = atomic_read((atomic_t *)(np + xennet_stats[i].offset));
2557}
2558
2559static void xennet_get_strings(struct net_device *dev, u32 stringset, u8 * data)
2560{
2561 int i;
2562
2563 switch (stringset) {
2564 case ETH_SS_STATS:
2565 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++)
2566 memcpy(data + i * ETH_GSTRING_LEN,
2567 xennet_stats[i].name, ETH_GSTRING_LEN);
2568 break;
2569 }
2570}
2571
2572static const struct ethtool_ops xennet_ethtool_ops =
2573{
2574 .get_link = ethtool_op_get_link,
2575
2576 .get_sset_count = xennet_get_sset_count,
2577 .get_ethtool_stats = xennet_get_ethtool_stats,
2578 .get_strings = xennet_get_strings,
2579 .get_ts_info = ethtool_op_get_ts_info,
2580};
2581
2582#ifdef CONFIG_SYSFS
2583static ssize_t show_rxbuf(struct device *dev,
2584 struct device_attribute *attr, char *buf)
2585{
2586 return sprintf(buf, "%lu\n", NET_RX_RING_SIZE);
2587}
2588
2589static ssize_t store_rxbuf(struct device *dev,
2590 struct device_attribute *attr,
2591 const char *buf, size_t len)
2592{
2593 char *endp;
2594
2595 if (!capable(CAP_NET_ADMIN))
2596 return -EPERM;
2597
2598 simple_strtoul(buf, &endp, 0);
2599 if (endp == buf)
2600 return -EBADMSG;
2601
2602 /* rxbuf_min and rxbuf_max are no longer configurable. */
2603
2604 return len;
2605}
2606
2607static DEVICE_ATTR(rxbuf_min, 0644, show_rxbuf, store_rxbuf);
2608static DEVICE_ATTR(rxbuf_max, 0644, show_rxbuf, store_rxbuf);
2609static DEVICE_ATTR(rxbuf_cur, 0444, show_rxbuf, NULL);
2610
2611static struct attribute *xennet_dev_attrs[] = {
2612 &dev_attr_rxbuf_min.attr,
2613 &dev_attr_rxbuf_max.attr,
2614 &dev_attr_rxbuf_cur.attr,
2615 NULL
2616};
2617
2618static const struct attribute_group xennet_dev_group = {
2619 .attrs = xennet_dev_attrs
2620};
2621#endif /* CONFIG_SYSFS */
2622
2623static void xennet_bus_close(struct xenbus_device *dev)
2624{
2625 int ret;
2626
2627 if (xenbus_read_driver_state(dev->otherend) == XenbusStateClosed)
2628 return;
2629 do {
2630 xenbus_switch_state(dev, XenbusStateClosing);
2631 ret = wait_event_timeout(module_wq,
2632 xenbus_read_driver_state(dev->otherend) ==
2633 XenbusStateClosing ||
2634 xenbus_read_driver_state(dev->otherend) ==
2635 XenbusStateClosed ||
2636 xenbus_read_driver_state(dev->otherend) ==
2637 XenbusStateUnknown,
2638 XENNET_TIMEOUT);
2639 } while (!ret);
2640
2641 if (xenbus_read_driver_state(dev->otherend) == XenbusStateClosed)
2642 return;
2643
2644 do {
2645 xenbus_switch_state(dev, XenbusStateClosed);
2646 ret = wait_event_timeout(module_wq,
2647 xenbus_read_driver_state(dev->otherend) ==
2648 XenbusStateClosed ||
2649 xenbus_read_driver_state(dev->otherend) ==
2650 XenbusStateUnknown,
2651 XENNET_TIMEOUT);
2652 } while (!ret);
2653}
2654
2655static void xennet_remove(struct xenbus_device *dev)
2656{
2657 struct netfront_info *info = dev_get_drvdata(&dev->dev);
2658
2659 xennet_bus_close(dev);
2660 xennet_disconnect_backend(info);
2661
2662 if (info->netdev->reg_state == NETREG_REGISTERED)
2663 unregister_netdev(info->netdev);
2664
2665 if (info->queues) {
2666 rtnl_lock();
2667 xennet_destroy_queues(info);
2668 rtnl_unlock();
2669 }
2670 xennet_free_netdev(info->netdev);
2671}
2672
2673static const struct xenbus_device_id netfront_ids[] = {
2674 { "vif" },
2675 { "" }
2676};
2677
2678static struct xenbus_driver netfront_driver = {
2679 .ids = netfront_ids,
2680 .probe = netfront_probe,
2681 .remove = xennet_remove,
2682 .resume = netfront_resume,
2683 .otherend_changed = netback_changed,
2684};
2685
2686static int __init netif_init(void)
2687{
2688 if (!xen_domain())
2689 return -ENODEV;
2690
2691 if (!xen_has_pv_nic_devices())
2692 return -ENODEV;
2693
2694 pr_info("Initialising Xen virtual ethernet driver\n");
2695
2696 /* Allow as many queues as there are CPUs inut max. 8 if user has not
2697 * specified a value.
2698 */
2699 if (xennet_max_queues == 0)
2700 xennet_max_queues = min_t(unsigned int, MAX_QUEUES_DEFAULT,
2701 num_online_cpus());
2702
2703 return xenbus_register_frontend(&netfront_driver);
2704}
2705module_init(netif_init);
2706
2707
2708static void __exit netif_exit(void)
2709{
2710 xenbus_unregister_driver(&netfront_driver);
2711}
2712module_exit(netif_exit);
2713
2714MODULE_DESCRIPTION("Xen virtual network device frontend");
2715MODULE_LICENSE("GPL");
2716MODULE_ALIAS("xen:vif");
2717MODULE_ALIAS("xennet");
1/*
2 * Virtual network driver for conversing with remote driver backends.
3 *
4 * Copyright (c) 2002-2005, K A Fraser
5 * Copyright (c) 2005, XenSource Ltd
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License version 2
9 * as published by the Free Software Foundation; or, when distributed
10 * separately from the Linux kernel or incorporated into other
11 * software packages, subject to the following license:
12 *
13 * Permission is hereby granted, free of charge, to any person obtaining a copy
14 * of this source file (the "Software"), to deal in the Software without
15 * restriction, including without limitation the rights to use, copy, modify,
16 * merge, publish, distribute, sublicense, and/or sell copies of the Software,
17 * and to permit persons to whom the Software is furnished to do so, subject to
18 * the following conditions:
19 *
20 * The above copyright notice and this permission notice shall be included in
21 * all copies or substantial portions of the Software.
22 *
23 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
24 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
25 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
26 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
27 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
28 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
29 * IN THE SOFTWARE.
30 */
31
32#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
33
34#include <linux/module.h>
35#include <linux/kernel.h>
36#include <linux/netdevice.h>
37#include <linux/etherdevice.h>
38#include <linux/skbuff.h>
39#include <linux/ethtool.h>
40#include <linux/if_ether.h>
41#include <net/tcp.h>
42#include <linux/udp.h>
43#include <linux/moduleparam.h>
44#include <linux/mm.h>
45#include <linux/slab.h>
46#include <net/ip.h>
47#include <linux/bpf.h>
48#include <net/page_pool/types.h>
49#include <linux/bpf_trace.h>
50
51#include <xen/xen.h>
52#include <xen/xenbus.h>
53#include <xen/events.h>
54#include <xen/page.h>
55#include <xen/platform_pci.h>
56#include <xen/grant_table.h>
57
58#include <xen/interface/io/netif.h>
59#include <xen/interface/memory.h>
60#include <xen/interface/grant_table.h>
61
62/* Module parameters */
63#define MAX_QUEUES_DEFAULT 8
64static unsigned int xennet_max_queues;
65module_param_named(max_queues, xennet_max_queues, uint, 0644);
66MODULE_PARM_DESC(max_queues,
67 "Maximum number of queues per virtual interface");
68
69static bool __read_mostly xennet_trusted = true;
70module_param_named(trusted, xennet_trusted, bool, 0644);
71MODULE_PARM_DESC(trusted, "Is the backend trusted");
72
73#define XENNET_TIMEOUT (5 * HZ)
74
75static const struct ethtool_ops xennet_ethtool_ops;
76
77struct netfront_cb {
78 int pull_to;
79};
80
81#define NETFRONT_SKB_CB(skb) ((struct netfront_cb *)((skb)->cb))
82
83#define RX_COPY_THRESHOLD 256
84
85#define NET_TX_RING_SIZE __CONST_RING_SIZE(xen_netif_tx, XEN_PAGE_SIZE)
86#define NET_RX_RING_SIZE __CONST_RING_SIZE(xen_netif_rx, XEN_PAGE_SIZE)
87
88/* Minimum number of Rx slots (includes slot for GSO metadata). */
89#define NET_RX_SLOTS_MIN (XEN_NETIF_NR_SLOTS_MIN + 1)
90
91/* Queue name is interface name with "-qNNN" appended */
92#define QUEUE_NAME_SIZE (IFNAMSIZ + 6)
93
94/* IRQ name is queue name with "-tx" or "-rx" appended */
95#define IRQ_NAME_SIZE (QUEUE_NAME_SIZE + 3)
96
97static DECLARE_WAIT_QUEUE_HEAD(module_wq);
98
99struct netfront_stats {
100 u64 packets;
101 u64 bytes;
102 struct u64_stats_sync syncp;
103};
104
105struct netfront_info;
106
107struct netfront_queue {
108 unsigned int id; /* Queue ID, 0-based */
109 char name[QUEUE_NAME_SIZE]; /* DEVNAME-qN */
110 struct netfront_info *info;
111
112 struct bpf_prog __rcu *xdp_prog;
113
114 struct napi_struct napi;
115
116 /* Split event channels support, tx_* == rx_* when using
117 * single event channel.
118 */
119 unsigned int tx_evtchn, rx_evtchn;
120 unsigned int tx_irq, rx_irq;
121 /* Only used when split event channels support is enabled */
122 char tx_irq_name[IRQ_NAME_SIZE]; /* DEVNAME-qN-tx */
123 char rx_irq_name[IRQ_NAME_SIZE]; /* DEVNAME-qN-rx */
124
125 spinlock_t tx_lock;
126 struct xen_netif_tx_front_ring tx;
127 int tx_ring_ref;
128
129 /*
130 * {tx,rx}_skbs store outstanding skbuffs. Free tx_skb entries
131 * are linked from tx_skb_freelist through tx_link.
132 */
133 struct sk_buff *tx_skbs[NET_TX_RING_SIZE];
134 unsigned short tx_link[NET_TX_RING_SIZE];
135#define TX_LINK_NONE 0xffff
136#define TX_PENDING 0xfffe
137 grant_ref_t gref_tx_head;
138 grant_ref_t grant_tx_ref[NET_TX_RING_SIZE];
139 struct page *grant_tx_page[NET_TX_RING_SIZE];
140 unsigned tx_skb_freelist;
141 unsigned int tx_pend_queue;
142
143 spinlock_t rx_lock ____cacheline_aligned_in_smp;
144 struct xen_netif_rx_front_ring rx;
145 int rx_ring_ref;
146
147 struct timer_list rx_refill_timer;
148
149 struct sk_buff *rx_skbs[NET_RX_RING_SIZE];
150 grant_ref_t gref_rx_head;
151 grant_ref_t grant_rx_ref[NET_RX_RING_SIZE];
152
153 unsigned int rx_rsp_unconsumed;
154 spinlock_t rx_cons_lock;
155
156 struct page_pool *page_pool;
157 struct xdp_rxq_info xdp_rxq;
158};
159
160struct netfront_info {
161 struct list_head list;
162 struct net_device *netdev;
163
164 struct xenbus_device *xbdev;
165
166 /* Multi-queue support */
167 struct netfront_queue *queues;
168
169 /* Statistics */
170 struct netfront_stats __percpu *rx_stats;
171 struct netfront_stats __percpu *tx_stats;
172
173 /* XDP state */
174 bool netback_has_xdp_headroom;
175 bool netfront_xdp_enabled;
176
177 /* Is device behaving sane? */
178 bool broken;
179
180 /* Should skbs be bounced into a zeroed buffer? */
181 bool bounce;
182
183 atomic_t rx_gso_checksum_fixup;
184};
185
186struct netfront_rx_info {
187 struct xen_netif_rx_response rx;
188 struct xen_netif_extra_info extras[XEN_NETIF_EXTRA_TYPE_MAX - 1];
189};
190
191/*
192 * Access macros for acquiring freeing slots in tx_skbs[].
193 */
194
195static void add_id_to_list(unsigned *head, unsigned short *list,
196 unsigned short id)
197{
198 list[id] = *head;
199 *head = id;
200}
201
202static unsigned short get_id_from_list(unsigned *head, unsigned short *list)
203{
204 unsigned int id = *head;
205
206 if (id != TX_LINK_NONE) {
207 *head = list[id];
208 list[id] = TX_LINK_NONE;
209 }
210 return id;
211}
212
213static int xennet_rxidx(RING_IDX idx)
214{
215 return idx & (NET_RX_RING_SIZE - 1);
216}
217
218static struct sk_buff *xennet_get_rx_skb(struct netfront_queue *queue,
219 RING_IDX ri)
220{
221 int i = xennet_rxidx(ri);
222 struct sk_buff *skb = queue->rx_skbs[i];
223 queue->rx_skbs[i] = NULL;
224 return skb;
225}
226
227static grant_ref_t xennet_get_rx_ref(struct netfront_queue *queue,
228 RING_IDX ri)
229{
230 int i = xennet_rxidx(ri);
231 grant_ref_t ref = queue->grant_rx_ref[i];
232 queue->grant_rx_ref[i] = INVALID_GRANT_REF;
233 return ref;
234}
235
236#ifdef CONFIG_SYSFS
237static const struct attribute_group xennet_dev_group;
238#endif
239
240static bool xennet_can_sg(struct net_device *dev)
241{
242 return dev->features & NETIF_F_SG;
243}
244
245
246static void rx_refill_timeout(struct timer_list *t)
247{
248 struct netfront_queue *queue = from_timer(queue, t, rx_refill_timer);
249 napi_schedule(&queue->napi);
250}
251
252static int netfront_tx_slot_available(struct netfront_queue *queue)
253{
254 return (queue->tx.req_prod_pvt - queue->tx.rsp_cons) <
255 (NET_TX_RING_SIZE - XEN_NETIF_NR_SLOTS_MIN - 1);
256}
257
258static void xennet_maybe_wake_tx(struct netfront_queue *queue)
259{
260 struct net_device *dev = queue->info->netdev;
261 struct netdev_queue *dev_queue = netdev_get_tx_queue(dev, queue->id);
262
263 if (unlikely(netif_tx_queue_stopped(dev_queue)) &&
264 netfront_tx_slot_available(queue) &&
265 likely(netif_running(dev)))
266 netif_tx_wake_queue(netdev_get_tx_queue(dev, queue->id));
267}
268
269
270static struct sk_buff *xennet_alloc_one_rx_buffer(struct netfront_queue *queue)
271{
272 struct sk_buff *skb;
273 struct page *page;
274
275 skb = __netdev_alloc_skb(queue->info->netdev,
276 RX_COPY_THRESHOLD + NET_IP_ALIGN,
277 GFP_ATOMIC | __GFP_NOWARN);
278 if (unlikely(!skb))
279 return NULL;
280
281 page = page_pool_alloc_pages(queue->page_pool,
282 GFP_ATOMIC | __GFP_NOWARN | __GFP_ZERO);
283 if (unlikely(!page)) {
284 kfree_skb(skb);
285 return NULL;
286 }
287 skb_add_rx_frag(skb, 0, page, 0, 0, PAGE_SIZE);
288 skb_mark_for_recycle(skb);
289
290 /* Align ip header to a 16 bytes boundary */
291 skb_reserve(skb, NET_IP_ALIGN);
292 skb->dev = queue->info->netdev;
293
294 return skb;
295}
296
297
298static void xennet_alloc_rx_buffers(struct netfront_queue *queue)
299{
300 RING_IDX req_prod = queue->rx.req_prod_pvt;
301 int notify;
302 int err = 0;
303
304 if (unlikely(!netif_carrier_ok(queue->info->netdev)))
305 return;
306
307 for (req_prod = queue->rx.req_prod_pvt;
308 req_prod - queue->rx.rsp_cons < NET_RX_RING_SIZE;
309 req_prod++) {
310 struct sk_buff *skb;
311 unsigned short id;
312 grant_ref_t ref;
313 struct page *page;
314 struct xen_netif_rx_request *req;
315
316 skb = xennet_alloc_one_rx_buffer(queue);
317 if (!skb) {
318 err = -ENOMEM;
319 break;
320 }
321
322 id = xennet_rxidx(req_prod);
323
324 BUG_ON(queue->rx_skbs[id]);
325 queue->rx_skbs[id] = skb;
326
327 ref = gnttab_claim_grant_reference(&queue->gref_rx_head);
328 WARN_ON_ONCE(IS_ERR_VALUE((unsigned long)(int)ref));
329 queue->grant_rx_ref[id] = ref;
330
331 page = skb_frag_page(&skb_shinfo(skb)->frags[0]);
332
333 req = RING_GET_REQUEST(&queue->rx, req_prod);
334 gnttab_page_grant_foreign_access_ref_one(ref,
335 queue->info->xbdev->otherend_id,
336 page,
337 0);
338 req->id = id;
339 req->gref = ref;
340 }
341
342 queue->rx.req_prod_pvt = req_prod;
343
344 /* Try again later if there are not enough requests or skb allocation
345 * failed.
346 * Enough requests is quantified as the sum of newly created slots and
347 * the unconsumed slots at the backend.
348 */
349 if (req_prod - queue->rx.rsp_cons < NET_RX_SLOTS_MIN ||
350 unlikely(err)) {
351 mod_timer(&queue->rx_refill_timer, jiffies + (HZ/10));
352 return;
353 }
354
355 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->rx, notify);
356 if (notify)
357 notify_remote_via_irq(queue->rx_irq);
358}
359
360static int xennet_open(struct net_device *dev)
361{
362 struct netfront_info *np = netdev_priv(dev);
363 unsigned int num_queues = dev->real_num_tx_queues;
364 unsigned int i = 0;
365 struct netfront_queue *queue = NULL;
366
367 if (!np->queues || np->broken)
368 return -ENODEV;
369
370 for (i = 0; i < num_queues; ++i) {
371 queue = &np->queues[i];
372 napi_enable(&queue->napi);
373
374 spin_lock_bh(&queue->rx_lock);
375 if (netif_carrier_ok(dev)) {
376 xennet_alloc_rx_buffers(queue);
377 queue->rx.sring->rsp_event = queue->rx.rsp_cons + 1;
378 if (RING_HAS_UNCONSUMED_RESPONSES(&queue->rx))
379 napi_schedule(&queue->napi);
380 }
381 spin_unlock_bh(&queue->rx_lock);
382 }
383
384 netif_tx_start_all_queues(dev);
385
386 return 0;
387}
388
389static bool xennet_tx_buf_gc(struct netfront_queue *queue)
390{
391 RING_IDX cons, prod;
392 unsigned short id;
393 struct sk_buff *skb;
394 bool more_to_do;
395 bool work_done = false;
396 const struct device *dev = &queue->info->netdev->dev;
397
398 BUG_ON(!netif_carrier_ok(queue->info->netdev));
399
400 do {
401 prod = queue->tx.sring->rsp_prod;
402 if (RING_RESPONSE_PROD_OVERFLOW(&queue->tx, prod)) {
403 dev_alert(dev, "Illegal number of responses %u\n",
404 prod - queue->tx.rsp_cons);
405 goto err;
406 }
407 rmb(); /* Ensure we see responses up to 'rp'. */
408
409 for (cons = queue->tx.rsp_cons; cons != prod; cons++) {
410 struct xen_netif_tx_response txrsp;
411
412 work_done = true;
413
414 RING_COPY_RESPONSE(&queue->tx, cons, &txrsp);
415 if (txrsp.status == XEN_NETIF_RSP_NULL)
416 continue;
417
418 id = txrsp.id;
419 if (id >= RING_SIZE(&queue->tx)) {
420 dev_alert(dev,
421 "Response has incorrect id (%u)\n",
422 id);
423 goto err;
424 }
425 if (queue->tx_link[id] != TX_PENDING) {
426 dev_alert(dev,
427 "Response for inactive request\n");
428 goto err;
429 }
430
431 queue->tx_link[id] = TX_LINK_NONE;
432 skb = queue->tx_skbs[id];
433 queue->tx_skbs[id] = NULL;
434 if (unlikely(!gnttab_end_foreign_access_ref(
435 queue->grant_tx_ref[id]))) {
436 dev_alert(dev,
437 "Grant still in use by backend domain\n");
438 goto err;
439 }
440 gnttab_release_grant_reference(
441 &queue->gref_tx_head, queue->grant_tx_ref[id]);
442 queue->grant_tx_ref[id] = INVALID_GRANT_REF;
443 queue->grant_tx_page[id] = NULL;
444 add_id_to_list(&queue->tx_skb_freelist, queue->tx_link, id);
445 dev_kfree_skb_irq(skb);
446 }
447
448 queue->tx.rsp_cons = prod;
449
450 RING_FINAL_CHECK_FOR_RESPONSES(&queue->tx, more_to_do);
451 } while (more_to_do);
452
453 xennet_maybe_wake_tx(queue);
454
455 return work_done;
456
457 err:
458 queue->info->broken = true;
459 dev_alert(dev, "Disabled for further use\n");
460
461 return work_done;
462}
463
464struct xennet_gnttab_make_txreq {
465 struct netfront_queue *queue;
466 struct sk_buff *skb;
467 struct page *page;
468 struct xen_netif_tx_request *tx; /* Last request on ring page */
469 struct xen_netif_tx_request tx_local; /* Last request local copy*/
470 unsigned int size;
471};
472
473static void xennet_tx_setup_grant(unsigned long gfn, unsigned int offset,
474 unsigned int len, void *data)
475{
476 struct xennet_gnttab_make_txreq *info = data;
477 unsigned int id;
478 struct xen_netif_tx_request *tx;
479 grant_ref_t ref;
480 /* convenient aliases */
481 struct page *page = info->page;
482 struct netfront_queue *queue = info->queue;
483 struct sk_buff *skb = info->skb;
484
485 id = get_id_from_list(&queue->tx_skb_freelist, queue->tx_link);
486 tx = RING_GET_REQUEST(&queue->tx, queue->tx.req_prod_pvt++);
487 ref = gnttab_claim_grant_reference(&queue->gref_tx_head);
488 WARN_ON_ONCE(IS_ERR_VALUE((unsigned long)(int)ref));
489
490 gnttab_grant_foreign_access_ref(ref, queue->info->xbdev->otherend_id,
491 gfn, GNTMAP_readonly);
492
493 queue->tx_skbs[id] = skb;
494 queue->grant_tx_page[id] = page;
495 queue->grant_tx_ref[id] = ref;
496
497 info->tx_local.id = id;
498 info->tx_local.gref = ref;
499 info->tx_local.offset = offset;
500 info->tx_local.size = len;
501 info->tx_local.flags = 0;
502
503 *tx = info->tx_local;
504
505 /*
506 * Put the request in the pending queue, it will be set to be pending
507 * when the producer index is about to be raised.
508 */
509 add_id_to_list(&queue->tx_pend_queue, queue->tx_link, id);
510
511 info->tx = tx;
512 info->size += info->tx_local.size;
513}
514
515static struct xen_netif_tx_request *xennet_make_first_txreq(
516 struct xennet_gnttab_make_txreq *info,
517 unsigned int offset, unsigned int len)
518{
519 info->size = 0;
520
521 gnttab_for_one_grant(info->page, offset, len, xennet_tx_setup_grant, info);
522
523 return info->tx;
524}
525
526static void xennet_make_one_txreq(unsigned long gfn, unsigned int offset,
527 unsigned int len, void *data)
528{
529 struct xennet_gnttab_make_txreq *info = data;
530
531 info->tx->flags |= XEN_NETTXF_more_data;
532 skb_get(info->skb);
533 xennet_tx_setup_grant(gfn, offset, len, data);
534}
535
536static void xennet_make_txreqs(
537 struct xennet_gnttab_make_txreq *info,
538 struct page *page,
539 unsigned int offset, unsigned int len)
540{
541 /* Skip unused frames from start of page */
542 page += offset >> PAGE_SHIFT;
543 offset &= ~PAGE_MASK;
544
545 while (len) {
546 info->page = page;
547 info->size = 0;
548
549 gnttab_foreach_grant_in_range(page, offset, len,
550 xennet_make_one_txreq,
551 info);
552
553 page++;
554 offset = 0;
555 len -= info->size;
556 }
557}
558
559/*
560 * Count how many ring slots are required to send this skb. Each frag
561 * might be a compound page.
562 */
563static int xennet_count_skb_slots(struct sk_buff *skb)
564{
565 int i, frags = skb_shinfo(skb)->nr_frags;
566 int slots;
567
568 slots = gnttab_count_grant(offset_in_page(skb->data),
569 skb_headlen(skb));
570
571 for (i = 0; i < frags; i++) {
572 skb_frag_t *frag = skb_shinfo(skb)->frags + i;
573 unsigned long size = skb_frag_size(frag);
574 unsigned long offset = skb_frag_off(frag);
575
576 /* Skip unused frames from start of page */
577 offset &= ~PAGE_MASK;
578
579 slots += gnttab_count_grant(offset, size);
580 }
581
582 return slots;
583}
584
585static u16 xennet_select_queue(struct net_device *dev, struct sk_buff *skb,
586 struct net_device *sb_dev)
587{
588 unsigned int num_queues = dev->real_num_tx_queues;
589 u32 hash;
590 u16 queue_idx;
591
592 /* First, check if there is only one queue */
593 if (num_queues == 1) {
594 queue_idx = 0;
595 } else {
596 hash = skb_get_hash(skb);
597 queue_idx = hash % num_queues;
598 }
599
600 return queue_idx;
601}
602
603static void xennet_mark_tx_pending(struct netfront_queue *queue)
604{
605 unsigned int i;
606
607 while ((i = get_id_from_list(&queue->tx_pend_queue, queue->tx_link)) !=
608 TX_LINK_NONE)
609 queue->tx_link[i] = TX_PENDING;
610}
611
612static int xennet_xdp_xmit_one(struct net_device *dev,
613 struct netfront_queue *queue,
614 struct xdp_frame *xdpf)
615{
616 struct netfront_info *np = netdev_priv(dev);
617 struct netfront_stats *tx_stats = this_cpu_ptr(np->tx_stats);
618 struct xennet_gnttab_make_txreq info = {
619 .queue = queue,
620 .skb = NULL,
621 .page = virt_to_page(xdpf->data),
622 };
623 int notify;
624
625 xennet_make_first_txreq(&info,
626 offset_in_page(xdpf->data),
627 xdpf->len);
628
629 xennet_mark_tx_pending(queue);
630
631 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->tx, notify);
632 if (notify)
633 notify_remote_via_irq(queue->tx_irq);
634
635 u64_stats_update_begin(&tx_stats->syncp);
636 tx_stats->bytes += xdpf->len;
637 tx_stats->packets++;
638 u64_stats_update_end(&tx_stats->syncp);
639
640 xennet_tx_buf_gc(queue);
641
642 return 0;
643}
644
645static int xennet_xdp_xmit(struct net_device *dev, int n,
646 struct xdp_frame **frames, u32 flags)
647{
648 unsigned int num_queues = dev->real_num_tx_queues;
649 struct netfront_info *np = netdev_priv(dev);
650 struct netfront_queue *queue = NULL;
651 unsigned long irq_flags;
652 int nxmit = 0;
653 int i;
654
655 if (unlikely(np->broken))
656 return -ENODEV;
657 if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK))
658 return -EINVAL;
659
660 queue = &np->queues[smp_processor_id() % num_queues];
661
662 spin_lock_irqsave(&queue->tx_lock, irq_flags);
663 for (i = 0; i < n; i++) {
664 struct xdp_frame *xdpf = frames[i];
665
666 if (!xdpf)
667 continue;
668 if (xennet_xdp_xmit_one(dev, queue, xdpf))
669 break;
670 nxmit++;
671 }
672 spin_unlock_irqrestore(&queue->tx_lock, irq_flags);
673
674 return nxmit;
675}
676
677static struct sk_buff *bounce_skb(const struct sk_buff *skb)
678{
679 unsigned int headerlen = skb_headroom(skb);
680 /* Align size to allocate full pages and avoid contiguous data leaks */
681 unsigned int size = ALIGN(skb_end_offset(skb) + skb->data_len,
682 XEN_PAGE_SIZE);
683 struct sk_buff *n = alloc_skb(size, GFP_ATOMIC | __GFP_ZERO);
684
685 if (!n)
686 return NULL;
687
688 if (!IS_ALIGNED((uintptr_t)n->head, XEN_PAGE_SIZE)) {
689 WARN_ONCE(1, "misaligned skb allocated\n");
690 kfree_skb(n);
691 return NULL;
692 }
693
694 /* Set the data pointer */
695 skb_reserve(n, headerlen);
696 /* Set the tail pointer and length */
697 skb_put(n, skb->len);
698
699 BUG_ON(skb_copy_bits(skb, -headerlen, n->head, headerlen + skb->len));
700
701 skb_copy_header(n, skb);
702 return n;
703}
704
705#define MAX_XEN_SKB_FRAGS (65536 / XEN_PAGE_SIZE + 1)
706
707static netdev_tx_t xennet_start_xmit(struct sk_buff *skb, struct net_device *dev)
708{
709 struct netfront_info *np = netdev_priv(dev);
710 struct netfront_stats *tx_stats = this_cpu_ptr(np->tx_stats);
711 struct xen_netif_tx_request *first_tx;
712 unsigned int i;
713 int notify;
714 int slots;
715 struct page *page;
716 unsigned int offset;
717 unsigned int len;
718 unsigned long flags;
719 struct netfront_queue *queue = NULL;
720 struct xennet_gnttab_make_txreq info = { };
721 unsigned int num_queues = dev->real_num_tx_queues;
722 u16 queue_index;
723 struct sk_buff *nskb;
724
725 /* Drop the packet if no queues are set up */
726 if (num_queues < 1)
727 goto drop;
728 if (unlikely(np->broken))
729 goto drop;
730 /* Determine which queue to transmit this SKB on */
731 queue_index = skb_get_queue_mapping(skb);
732 queue = &np->queues[queue_index];
733
734 /* If skb->len is too big for wire format, drop skb and alert
735 * user about misconfiguration.
736 */
737 if (unlikely(skb->len > XEN_NETIF_MAX_TX_SIZE)) {
738 net_alert_ratelimited(
739 "xennet: skb->len = %u, too big for wire format\n",
740 skb->len);
741 goto drop;
742 }
743
744 slots = xennet_count_skb_slots(skb);
745 if (unlikely(slots > MAX_XEN_SKB_FRAGS + 1)) {
746 net_dbg_ratelimited("xennet: skb rides the rocket: %d slots, %d bytes\n",
747 slots, skb->len);
748 if (skb_linearize(skb))
749 goto drop;
750 }
751
752 page = virt_to_page(skb->data);
753 offset = offset_in_page(skb->data);
754
755 /* The first req should be at least ETH_HLEN size or the packet will be
756 * dropped by netback.
757 *
758 * If the backend is not trusted bounce all data to zeroed pages to
759 * avoid exposing contiguous data on the granted page not belonging to
760 * the skb.
761 */
762 if (np->bounce || unlikely(PAGE_SIZE - offset < ETH_HLEN)) {
763 nskb = bounce_skb(skb);
764 if (!nskb)
765 goto drop;
766 dev_consume_skb_any(skb);
767 skb = nskb;
768 page = virt_to_page(skb->data);
769 offset = offset_in_page(skb->data);
770 }
771
772 len = skb_headlen(skb);
773
774 spin_lock_irqsave(&queue->tx_lock, flags);
775
776 if (unlikely(!netif_carrier_ok(dev) ||
777 (slots > 1 && !xennet_can_sg(dev)) ||
778 netif_needs_gso(skb, netif_skb_features(skb)))) {
779 spin_unlock_irqrestore(&queue->tx_lock, flags);
780 goto drop;
781 }
782
783 /* First request for the linear area. */
784 info.queue = queue;
785 info.skb = skb;
786 info.page = page;
787 first_tx = xennet_make_first_txreq(&info, offset, len);
788 offset += info.tx_local.size;
789 if (offset == PAGE_SIZE) {
790 page++;
791 offset = 0;
792 }
793 len -= info.tx_local.size;
794
795 if (skb->ip_summed == CHECKSUM_PARTIAL)
796 /* local packet? */
797 first_tx->flags |= XEN_NETTXF_csum_blank |
798 XEN_NETTXF_data_validated;
799 else if (skb->ip_summed == CHECKSUM_UNNECESSARY)
800 /* remote but checksummed. */
801 first_tx->flags |= XEN_NETTXF_data_validated;
802
803 /* Optional extra info after the first request. */
804 if (skb_shinfo(skb)->gso_size) {
805 struct xen_netif_extra_info *gso;
806
807 gso = (struct xen_netif_extra_info *)
808 RING_GET_REQUEST(&queue->tx, queue->tx.req_prod_pvt++);
809
810 first_tx->flags |= XEN_NETTXF_extra_info;
811
812 gso->u.gso.size = skb_shinfo(skb)->gso_size;
813 gso->u.gso.type = (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6) ?
814 XEN_NETIF_GSO_TYPE_TCPV6 :
815 XEN_NETIF_GSO_TYPE_TCPV4;
816 gso->u.gso.pad = 0;
817 gso->u.gso.features = 0;
818
819 gso->type = XEN_NETIF_EXTRA_TYPE_GSO;
820 gso->flags = 0;
821 }
822
823 /* Requests for the rest of the linear area. */
824 xennet_make_txreqs(&info, page, offset, len);
825
826 /* Requests for all the frags. */
827 for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
828 skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
829 xennet_make_txreqs(&info, skb_frag_page(frag),
830 skb_frag_off(frag),
831 skb_frag_size(frag));
832 }
833
834 /* First request has the packet length. */
835 first_tx->size = skb->len;
836
837 /* timestamp packet in software */
838 skb_tx_timestamp(skb);
839
840 xennet_mark_tx_pending(queue);
841
842 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->tx, notify);
843 if (notify)
844 notify_remote_via_irq(queue->tx_irq);
845
846 u64_stats_update_begin(&tx_stats->syncp);
847 tx_stats->bytes += skb->len;
848 tx_stats->packets++;
849 u64_stats_update_end(&tx_stats->syncp);
850
851 /* Note: It is not safe to access skb after xennet_tx_buf_gc()! */
852 xennet_tx_buf_gc(queue);
853
854 if (!netfront_tx_slot_available(queue))
855 netif_tx_stop_queue(netdev_get_tx_queue(dev, queue->id));
856
857 spin_unlock_irqrestore(&queue->tx_lock, flags);
858
859 return NETDEV_TX_OK;
860
861 drop:
862 dev->stats.tx_dropped++;
863 dev_kfree_skb_any(skb);
864 return NETDEV_TX_OK;
865}
866
867static int xennet_close(struct net_device *dev)
868{
869 struct netfront_info *np = netdev_priv(dev);
870 unsigned int num_queues = dev->real_num_tx_queues;
871 unsigned int i;
872 struct netfront_queue *queue;
873 netif_tx_stop_all_queues(np->netdev);
874 for (i = 0; i < num_queues; ++i) {
875 queue = &np->queues[i];
876 napi_disable(&queue->napi);
877 }
878 return 0;
879}
880
881static void xennet_destroy_queues(struct netfront_info *info)
882{
883 unsigned int i;
884
885 for (i = 0; i < info->netdev->real_num_tx_queues; i++) {
886 struct netfront_queue *queue = &info->queues[i];
887
888 if (netif_running(info->netdev))
889 napi_disable(&queue->napi);
890 netif_napi_del(&queue->napi);
891 }
892
893 kfree(info->queues);
894 info->queues = NULL;
895}
896
897static void xennet_uninit(struct net_device *dev)
898{
899 struct netfront_info *np = netdev_priv(dev);
900 xennet_destroy_queues(np);
901}
902
903static void xennet_set_rx_rsp_cons(struct netfront_queue *queue, RING_IDX val)
904{
905 unsigned long flags;
906
907 spin_lock_irqsave(&queue->rx_cons_lock, flags);
908 queue->rx.rsp_cons = val;
909 queue->rx_rsp_unconsumed = XEN_RING_NR_UNCONSUMED_RESPONSES(&queue->rx);
910 spin_unlock_irqrestore(&queue->rx_cons_lock, flags);
911}
912
913static void xennet_move_rx_slot(struct netfront_queue *queue, struct sk_buff *skb,
914 grant_ref_t ref)
915{
916 int new = xennet_rxidx(queue->rx.req_prod_pvt);
917
918 BUG_ON(queue->rx_skbs[new]);
919 queue->rx_skbs[new] = skb;
920 queue->grant_rx_ref[new] = ref;
921 RING_GET_REQUEST(&queue->rx, queue->rx.req_prod_pvt)->id = new;
922 RING_GET_REQUEST(&queue->rx, queue->rx.req_prod_pvt)->gref = ref;
923 queue->rx.req_prod_pvt++;
924}
925
926static int xennet_get_extras(struct netfront_queue *queue,
927 struct xen_netif_extra_info *extras,
928 RING_IDX rp)
929
930{
931 struct xen_netif_extra_info extra;
932 struct device *dev = &queue->info->netdev->dev;
933 RING_IDX cons = queue->rx.rsp_cons;
934 int err = 0;
935
936 do {
937 struct sk_buff *skb;
938 grant_ref_t ref;
939
940 if (unlikely(cons + 1 == rp)) {
941 if (net_ratelimit())
942 dev_warn(dev, "Missing extra info\n");
943 err = -EBADR;
944 break;
945 }
946
947 RING_COPY_RESPONSE(&queue->rx, ++cons, &extra);
948
949 if (unlikely(!extra.type ||
950 extra.type >= XEN_NETIF_EXTRA_TYPE_MAX)) {
951 if (net_ratelimit())
952 dev_warn(dev, "Invalid extra type: %d\n",
953 extra.type);
954 err = -EINVAL;
955 } else {
956 extras[extra.type - 1] = extra;
957 }
958
959 skb = xennet_get_rx_skb(queue, cons);
960 ref = xennet_get_rx_ref(queue, cons);
961 xennet_move_rx_slot(queue, skb, ref);
962 } while (extra.flags & XEN_NETIF_EXTRA_FLAG_MORE);
963
964 xennet_set_rx_rsp_cons(queue, cons);
965 return err;
966}
967
968static u32 xennet_run_xdp(struct netfront_queue *queue, struct page *pdata,
969 struct xen_netif_rx_response *rx, struct bpf_prog *prog,
970 struct xdp_buff *xdp, bool *need_xdp_flush)
971{
972 struct xdp_frame *xdpf;
973 u32 len = rx->status;
974 u32 act;
975 int err;
976
977 xdp_init_buff(xdp, XEN_PAGE_SIZE - XDP_PACKET_HEADROOM,
978 &queue->xdp_rxq);
979 xdp_prepare_buff(xdp, page_address(pdata), XDP_PACKET_HEADROOM,
980 len, false);
981
982 act = bpf_prog_run_xdp(prog, xdp);
983 switch (act) {
984 case XDP_TX:
985 get_page(pdata);
986 xdpf = xdp_convert_buff_to_frame(xdp);
987 err = xennet_xdp_xmit(queue->info->netdev, 1, &xdpf, 0);
988 if (unlikely(!err))
989 xdp_return_frame_rx_napi(xdpf);
990 else if (unlikely(err < 0))
991 trace_xdp_exception(queue->info->netdev, prog, act);
992 break;
993 case XDP_REDIRECT:
994 get_page(pdata);
995 err = xdp_do_redirect(queue->info->netdev, xdp, prog);
996 *need_xdp_flush = true;
997 if (unlikely(err))
998 trace_xdp_exception(queue->info->netdev, prog, act);
999 break;
1000 case XDP_PASS:
1001 case XDP_DROP:
1002 break;
1003
1004 case XDP_ABORTED:
1005 trace_xdp_exception(queue->info->netdev, prog, act);
1006 break;
1007
1008 default:
1009 bpf_warn_invalid_xdp_action(queue->info->netdev, prog, act);
1010 }
1011
1012 return act;
1013}
1014
1015static int xennet_get_responses(struct netfront_queue *queue,
1016 struct netfront_rx_info *rinfo, RING_IDX rp,
1017 struct sk_buff_head *list,
1018 bool *need_xdp_flush)
1019{
1020 struct xen_netif_rx_response *rx = &rinfo->rx, rx_local;
1021 int max = XEN_NETIF_NR_SLOTS_MIN + (rx->status <= RX_COPY_THRESHOLD);
1022 RING_IDX cons = queue->rx.rsp_cons;
1023 struct sk_buff *skb = xennet_get_rx_skb(queue, cons);
1024 struct xen_netif_extra_info *extras = rinfo->extras;
1025 grant_ref_t ref = xennet_get_rx_ref(queue, cons);
1026 struct device *dev = &queue->info->netdev->dev;
1027 struct bpf_prog *xdp_prog;
1028 struct xdp_buff xdp;
1029 int slots = 1;
1030 int err = 0;
1031 u32 verdict;
1032
1033 if (rx->flags & XEN_NETRXF_extra_info) {
1034 err = xennet_get_extras(queue, extras, rp);
1035 if (!err) {
1036 if (extras[XEN_NETIF_EXTRA_TYPE_XDP - 1].type) {
1037 struct xen_netif_extra_info *xdp;
1038
1039 xdp = &extras[XEN_NETIF_EXTRA_TYPE_XDP - 1];
1040 rx->offset = xdp->u.xdp.headroom;
1041 }
1042 }
1043 cons = queue->rx.rsp_cons;
1044 }
1045
1046 for (;;) {
1047 /*
1048 * This definitely indicates a bug, either in this driver or in
1049 * the backend driver. In future this should flag the bad
1050 * situation to the system controller to reboot the backend.
1051 */
1052 if (ref == INVALID_GRANT_REF) {
1053 if (net_ratelimit())
1054 dev_warn(dev, "Bad rx response id %d.\n",
1055 rx->id);
1056 err = -EINVAL;
1057 goto next;
1058 }
1059
1060 if (unlikely(rx->status < 0 ||
1061 rx->offset + rx->status > XEN_PAGE_SIZE)) {
1062 if (net_ratelimit())
1063 dev_warn(dev, "rx->offset: %u, size: %d\n",
1064 rx->offset, rx->status);
1065 xennet_move_rx_slot(queue, skb, ref);
1066 err = -EINVAL;
1067 goto next;
1068 }
1069
1070 if (!gnttab_end_foreign_access_ref(ref)) {
1071 dev_alert(dev,
1072 "Grant still in use by backend domain\n");
1073 queue->info->broken = true;
1074 dev_alert(dev, "Disabled for further use\n");
1075 return -EINVAL;
1076 }
1077
1078 gnttab_release_grant_reference(&queue->gref_rx_head, ref);
1079
1080 rcu_read_lock();
1081 xdp_prog = rcu_dereference(queue->xdp_prog);
1082 if (xdp_prog) {
1083 if (!(rx->flags & XEN_NETRXF_more_data)) {
1084 /* currently only a single page contains data */
1085 verdict = xennet_run_xdp(queue,
1086 skb_frag_page(&skb_shinfo(skb)->frags[0]),
1087 rx, xdp_prog, &xdp, need_xdp_flush);
1088 if (verdict != XDP_PASS)
1089 err = -EINVAL;
1090 } else {
1091 /* drop the frame */
1092 err = -EINVAL;
1093 }
1094 }
1095 rcu_read_unlock();
1096
1097 __skb_queue_tail(list, skb);
1098
1099next:
1100 if (!(rx->flags & XEN_NETRXF_more_data))
1101 break;
1102
1103 if (cons + slots == rp) {
1104 if (net_ratelimit())
1105 dev_warn(dev, "Need more slots\n");
1106 err = -ENOENT;
1107 break;
1108 }
1109
1110 RING_COPY_RESPONSE(&queue->rx, cons + slots, &rx_local);
1111 rx = &rx_local;
1112 skb = xennet_get_rx_skb(queue, cons + slots);
1113 ref = xennet_get_rx_ref(queue, cons + slots);
1114 slots++;
1115 }
1116
1117 if (unlikely(slots > max)) {
1118 if (net_ratelimit())
1119 dev_warn(dev, "Too many slots\n");
1120 err = -E2BIG;
1121 }
1122
1123 if (unlikely(err))
1124 xennet_set_rx_rsp_cons(queue, cons + slots);
1125
1126 return err;
1127}
1128
1129static int xennet_set_skb_gso(struct sk_buff *skb,
1130 struct xen_netif_extra_info *gso)
1131{
1132 if (!gso->u.gso.size) {
1133 if (net_ratelimit())
1134 pr_warn("GSO size must not be zero\n");
1135 return -EINVAL;
1136 }
1137
1138 if (gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV4 &&
1139 gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV6) {
1140 if (net_ratelimit())
1141 pr_warn("Bad GSO type %d\n", gso->u.gso.type);
1142 return -EINVAL;
1143 }
1144
1145 skb_shinfo(skb)->gso_size = gso->u.gso.size;
1146 skb_shinfo(skb)->gso_type =
1147 (gso->u.gso.type == XEN_NETIF_GSO_TYPE_TCPV4) ?
1148 SKB_GSO_TCPV4 :
1149 SKB_GSO_TCPV6;
1150
1151 /* Header must be checked, and gso_segs computed. */
1152 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
1153 skb_shinfo(skb)->gso_segs = 0;
1154
1155 return 0;
1156}
1157
1158static int xennet_fill_frags(struct netfront_queue *queue,
1159 struct sk_buff *skb,
1160 struct sk_buff_head *list)
1161{
1162 RING_IDX cons = queue->rx.rsp_cons;
1163 struct sk_buff *nskb;
1164
1165 while ((nskb = __skb_dequeue(list))) {
1166 struct xen_netif_rx_response rx;
1167 skb_frag_t *nfrag = &skb_shinfo(nskb)->frags[0];
1168
1169 RING_COPY_RESPONSE(&queue->rx, ++cons, &rx);
1170
1171 if (skb_shinfo(skb)->nr_frags == MAX_SKB_FRAGS) {
1172 unsigned int pull_to = NETFRONT_SKB_CB(skb)->pull_to;
1173
1174 BUG_ON(pull_to < skb_headlen(skb));
1175 __pskb_pull_tail(skb, pull_to - skb_headlen(skb));
1176 }
1177 if (unlikely(skb_shinfo(skb)->nr_frags >= MAX_SKB_FRAGS)) {
1178 xennet_set_rx_rsp_cons(queue,
1179 ++cons + skb_queue_len(list));
1180 kfree_skb(nskb);
1181 return -ENOENT;
1182 }
1183
1184 skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags,
1185 skb_frag_page(nfrag),
1186 rx.offset, rx.status, PAGE_SIZE);
1187
1188 skb_shinfo(nskb)->nr_frags = 0;
1189 kfree_skb(nskb);
1190 }
1191
1192 xennet_set_rx_rsp_cons(queue, cons);
1193
1194 return 0;
1195}
1196
1197static int checksum_setup(struct net_device *dev, struct sk_buff *skb)
1198{
1199 bool recalculate_partial_csum = false;
1200
1201 /*
1202 * A GSO SKB must be CHECKSUM_PARTIAL. However some buggy
1203 * peers can fail to set NETRXF_csum_blank when sending a GSO
1204 * frame. In this case force the SKB to CHECKSUM_PARTIAL and
1205 * recalculate the partial checksum.
1206 */
1207 if (skb->ip_summed != CHECKSUM_PARTIAL && skb_is_gso(skb)) {
1208 struct netfront_info *np = netdev_priv(dev);
1209 atomic_inc(&np->rx_gso_checksum_fixup);
1210 skb->ip_summed = CHECKSUM_PARTIAL;
1211 recalculate_partial_csum = true;
1212 }
1213
1214 /* A non-CHECKSUM_PARTIAL SKB does not require setup. */
1215 if (skb->ip_summed != CHECKSUM_PARTIAL)
1216 return 0;
1217
1218 return skb_checksum_setup(skb, recalculate_partial_csum);
1219}
1220
1221static int handle_incoming_queue(struct netfront_queue *queue,
1222 struct sk_buff_head *rxq)
1223{
1224 struct netfront_stats *rx_stats = this_cpu_ptr(queue->info->rx_stats);
1225 int packets_dropped = 0;
1226 struct sk_buff *skb;
1227
1228 while ((skb = __skb_dequeue(rxq)) != NULL) {
1229 int pull_to = NETFRONT_SKB_CB(skb)->pull_to;
1230
1231 if (pull_to > skb_headlen(skb))
1232 __pskb_pull_tail(skb, pull_to - skb_headlen(skb));
1233
1234 /* Ethernet work: Delayed to here as it peeks the header. */
1235 skb->protocol = eth_type_trans(skb, queue->info->netdev);
1236 skb_reset_network_header(skb);
1237
1238 if (checksum_setup(queue->info->netdev, skb)) {
1239 kfree_skb(skb);
1240 packets_dropped++;
1241 queue->info->netdev->stats.rx_errors++;
1242 continue;
1243 }
1244
1245 u64_stats_update_begin(&rx_stats->syncp);
1246 rx_stats->packets++;
1247 rx_stats->bytes += skb->len;
1248 u64_stats_update_end(&rx_stats->syncp);
1249
1250 /* Pass it up. */
1251 napi_gro_receive(&queue->napi, skb);
1252 }
1253
1254 return packets_dropped;
1255}
1256
1257static int xennet_poll(struct napi_struct *napi, int budget)
1258{
1259 struct netfront_queue *queue = container_of(napi, struct netfront_queue, napi);
1260 struct net_device *dev = queue->info->netdev;
1261 struct sk_buff *skb;
1262 struct netfront_rx_info rinfo;
1263 struct xen_netif_rx_response *rx = &rinfo.rx;
1264 struct xen_netif_extra_info *extras = rinfo.extras;
1265 RING_IDX i, rp;
1266 int work_done;
1267 struct sk_buff_head rxq;
1268 struct sk_buff_head errq;
1269 struct sk_buff_head tmpq;
1270 int err;
1271 bool need_xdp_flush = false;
1272
1273 spin_lock(&queue->rx_lock);
1274
1275 skb_queue_head_init(&rxq);
1276 skb_queue_head_init(&errq);
1277 skb_queue_head_init(&tmpq);
1278
1279 rp = queue->rx.sring->rsp_prod;
1280 if (RING_RESPONSE_PROD_OVERFLOW(&queue->rx, rp)) {
1281 dev_alert(&dev->dev, "Illegal number of responses %u\n",
1282 rp - queue->rx.rsp_cons);
1283 queue->info->broken = true;
1284 spin_unlock(&queue->rx_lock);
1285 return 0;
1286 }
1287 rmb(); /* Ensure we see queued responses up to 'rp'. */
1288
1289 i = queue->rx.rsp_cons;
1290 work_done = 0;
1291 while ((i != rp) && (work_done < budget)) {
1292 RING_COPY_RESPONSE(&queue->rx, i, rx);
1293 memset(extras, 0, sizeof(rinfo.extras));
1294
1295 err = xennet_get_responses(queue, &rinfo, rp, &tmpq,
1296 &need_xdp_flush);
1297
1298 if (unlikely(err)) {
1299 if (queue->info->broken) {
1300 spin_unlock(&queue->rx_lock);
1301 return 0;
1302 }
1303err:
1304 while ((skb = __skb_dequeue(&tmpq)))
1305 __skb_queue_tail(&errq, skb);
1306 dev->stats.rx_errors++;
1307 i = queue->rx.rsp_cons;
1308 continue;
1309 }
1310
1311 skb = __skb_dequeue(&tmpq);
1312
1313 if (extras[XEN_NETIF_EXTRA_TYPE_GSO - 1].type) {
1314 struct xen_netif_extra_info *gso;
1315 gso = &extras[XEN_NETIF_EXTRA_TYPE_GSO - 1];
1316
1317 if (unlikely(xennet_set_skb_gso(skb, gso))) {
1318 __skb_queue_head(&tmpq, skb);
1319 xennet_set_rx_rsp_cons(queue,
1320 queue->rx.rsp_cons +
1321 skb_queue_len(&tmpq));
1322 goto err;
1323 }
1324 }
1325
1326 NETFRONT_SKB_CB(skb)->pull_to = rx->status;
1327 if (NETFRONT_SKB_CB(skb)->pull_to > RX_COPY_THRESHOLD)
1328 NETFRONT_SKB_CB(skb)->pull_to = RX_COPY_THRESHOLD;
1329
1330 skb_frag_off_set(&skb_shinfo(skb)->frags[0], rx->offset);
1331 skb_frag_size_set(&skb_shinfo(skb)->frags[0], rx->status);
1332 skb->data_len = rx->status;
1333 skb->len += rx->status;
1334
1335 if (unlikely(xennet_fill_frags(queue, skb, &tmpq)))
1336 goto err;
1337
1338 if (rx->flags & XEN_NETRXF_csum_blank)
1339 skb->ip_summed = CHECKSUM_PARTIAL;
1340 else if (rx->flags & XEN_NETRXF_data_validated)
1341 skb->ip_summed = CHECKSUM_UNNECESSARY;
1342
1343 __skb_queue_tail(&rxq, skb);
1344
1345 i = queue->rx.rsp_cons + 1;
1346 xennet_set_rx_rsp_cons(queue, i);
1347 work_done++;
1348 }
1349 if (need_xdp_flush)
1350 xdp_do_flush();
1351
1352 __skb_queue_purge(&errq);
1353
1354 work_done -= handle_incoming_queue(queue, &rxq);
1355
1356 xennet_alloc_rx_buffers(queue);
1357
1358 if (work_done < budget) {
1359 int more_to_do = 0;
1360
1361 napi_complete_done(napi, work_done);
1362
1363 RING_FINAL_CHECK_FOR_RESPONSES(&queue->rx, more_to_do);
1364 if (more_to_do)
1365 napi_schedule(napi);
1366 }
1367
1368 spin_unlock(&queue->rx_lock);
1369
1370 return work_done;
1371}
1372
1373static int xennet_change_mtu(struct net_device *dev, int mtu)
1374{
1375 int max = xennet_can_sg(dev) ? XEN_NETIF_MAX_TX_SIZE : ETH_DATA_LEN;
1376
1377 if (mtu > max)
1378 return -EINVAL;
1379 dev->mtu = mtu;
1380 return 0;
1381}
1382
1383static void xennet_get_stats64(struct net_device *dev,
1384 struct rtnl_link_stats64 *tot)
1385{
1386 struct netfront_info *np = netdev_priv(dev);
1387 int cpu;
1388
1389 for_each_possible_cpu(cpu) {
1390 struct netfront_stats *rx_stats = per_cpu_ptr(np->rx_stats, cpu);
1391 struct netfront_stats *tx_stats = per_cpu_ptr(np->tx_stats, cpu);
1392 u64 rx_packets, rx_bytes, tx_packets, tx_bytes;
1393 unsigned int start;
1394
1395 do {
1396 start = u64_stats_fetch_begin(&tx_stats->syncp);
1397 tx_packets = tx_stats->packets;
1398 tx_bytes = tx_stats->bytes;
1399 } while (u64_stats_fetch_retry(&tx_stats->syncp, start));
1400
1401 do {
1402 start = u64_stats_fetch_begin(&rx_stats->syncp);
1403 rx_packets = rx_stats->packets;
1404 rx_bytes = rx_stats->bytes;
1405 } while (u64_stats_fetch_retry(&rx_stats->syncp, start));
1406
1407 tot->rx_packets += rx_packets;
1408 tot->tx_packets += tx_packets;
1409 tot->rx_bytes += rx_bytes;
1410 tot->tx_bytes += tx_bytes;
1411 }
1412
1413 tot->rx_errors = dev->stats.rx_errors;
1414 tot->tx_dropped = dev->stats.tx_dropped;
1415}
1416
1417static void xennet_release_tx_bufs(struct netfront_queue *queue)
1418{
1419 struct sk_buff *skb;
1420 int i;
1421
1422 for (i = 0; i < NET_TX_RING_SIZE; i++) {
1423 /* Skip over entries which are actually freelist references */
1424 if (!queue->tx_skbs[i])
1425 continue;
1426
1427 skb = queue->tx_skbs[i];
1428 queue->tx_skbs[i] = NULL;
1429 get_page(queue->grant_tx_page[i]);
1430 gnttab_end_foreign_access(queue->grant_tx_ref[i],
1431 queue->grant_tx_page[i]);
1432 queue->grant_tx_page[i] = NULL;
1433 queue->grant_tx_ref[i] = INVALID_GRANT_REF;
1434 add_id_to_list(&queue->tx_skb_freelist, queue->tx_link, i);
1435 dev_kfree_skb_irq(skb);
1436 }
1437}
1438
1439static void xennet_release_rx_bufs(struct netfront_queue *queue)
1440{
1441 int id, ref;
1442
1443 spin_lock_bh(&queue->rx_lock);
1444
1445 for (id = 0; id < NET_RX_RING_SIZE; id++) {
1446 struct sk_buff *skb;
1447 struct page *page;
1448
1449 skb = queue->rx_skbs[id];
1450 if (!skb)
1451 continue;
1452
1453 ref = queue->grant_rx_ref[id];
1454 if (ref == INVALID_GRANT_REF)
1455 continue;
1456
1457 page = skb_frag_page(&skb_shinfo(skb)->frags[0]);
1458
1459 /* gnttab_end_foreign_access() needs a page ref until
1460 * foreign access is ended (which may be deferred).
1461 */
1462 get_page(page);
1463 gnttab_end_foreign_access(ref, page);
1464 queue->grant_rx_ref[id] = INVALID_GRANT_REF;
1465
1466 kfree_skb(skb);
1467 }
1468
1469 spin_unlock_bh(&queue->rx_lock);
1470}
1471
1472static netdev_features_t xennet_fix_features(struct net_device *dev,
1473 netdev_features_t features)
1474{
1475 struct netfront_info *np = netdev_priv(dev);
1476
1477 if (features & NETIF_F_SG &&
1478 !xenbus_read_unsigned(np->xbdev->otherend, "feature-sg", 0))
1479 features &= ~NETIF_F_SG;
1480
1481 if (features & NETIF_F_IPV6_CSUM &&
1482 !xenbus_read_unsigned(np->xbdev->otherend,
1483 "feature-ipv6-csum-offload", 0))
1484 features &= ~NETIF_F_IPV6_CSUM;
1485
1486 if (features & NETIF_F_TSO &&
1487 !xenbus_read_unsigned(np->xbdev->otherend, "feature-gso-tcpv4", 0))
1488 features &= ~NETIF_F_TSO;
1489
1490 if (features & NETIF_F_TSO6 &&
1491 !xenbus_read_unsigned(np->xbdev->otherend, "feature-gso-tcpv6", 0))
1492 features &= ~NETIF_F_TSO6;
1493
1494 return features;
1495}
1496
1497static int xennet_set_features(struct net_device *dev,
1498 netdev_features_t features)
1499{
1500 if (!(features & NETIF_F_SG) && dev->mtu > ETH_DATA_LEN) {
1501 netdev_info(dev, "Reducing MTU because no SG offload");
1502 dev->mtu = ETH_DATA_LEN;
1503 }
1504
1505 return 0;
1506}
1507
1508static bool xennet_handle_tx(struct netfront_queue *queue, unsigned int *eoi)
1509{
1510 unsigned long flags;
1511
1512 if (unlikely(queue->info->broken))
1513 return false;
1514
1515 spin_lock_irqsave(&queue->tx_lock, flags);
1516 if (xennet_tx_buf_gc(queue))
1517 *eoi = 0;
1518 spin_unlock_irqrestore(&queue->tx_lock, flags);
1519
1520 return true;
1521}
1522
1523static irqreturn_t xennet_tx_interrupt(int irq, void *dev_id)
1524{
1525 unsigned int eoiflag = XEN_EOI_FLAG_SPURIOUS;
1526
1527 if (likely(xennet_handle_tx(dev_id, &eoiflag)))
1528 xen_irq_lateeoi(irq, eoiflag);
1529
1530 return IRQ_HANDLED;
1531}
1532
1533static bool xennet_handle_rx(struct netfront_queue *queue, unsigned int *eoi)
1534{
1535 unsigned int work_queued;
1536 unsigned long flags;
1537
1538 if (unlikely(queue->info->broken))
1539 return false;
1540
1541 spin_lock_irqsave(&queue->rx_cons_lock, flags);
1542 work_queued = XEN_RING_NR_UNCONSUMED_RESPONSES(&queue->rx);
1543 if (work_queued > queue->rx_rsp_unconsumed) {
1544 queue->rx_rsp_unconsumed = work_queued;
1545 *eoi = 0;
1546 } else if (unlikely(work_queued < queue->rx_rsp_unconsumed)) {
1547 const struct device *dev = &queue->info->netdev->dev;
1548
1549 spin_unlock_irqrestore(&queue->rx_cons_lock, flags);
1550 dev_alert(dev, "RX producer index going backwards\n");
1551 dev_alert(dev, "Disabled for further use\n");
1552 queue->info->broken = true;
1553 return false;
1554 }
1555 spin_unlock_irqrestore(&queue->rx_cons_lock, flags);
1556
1557 if (likely(netif_carrier_ok(queue->info->netdev) && work_queued))
1558 napi_schedule(&queue->napi);
1559
1560 return true;
1561}
1562
1563static irqreturn_t xennet_rx_interrupt(int irq, void *dev_id)
1564{
1565 unsigned int eoiflag = XEN_EOI_FLAG_SPURIOUS;
1566
1567 if (likely(xennet_handle_rx(dev_id, &eoiflag)))
1568 xen_irq_lateeoi(irq, eoiflag);
1569
1570 return IRQ_HANDLED;
1571}
1572
1573static irqreturn_t xennet_interrupt(int irq, void *dev_id)
1574{
1575 unsigned int eoiflag = XEN_EOI_FLAG_SPURIOUS;
1576
1577 if (xennet_handle_tx(dev_id, &eoiflag) &&
1578 xennet_handle_rx(dev_id, &eoiflag))
1579 xen_irq_lateeoi(irq, eoiflag);
1580
1581 return IRQ_HANDLED;
1582}
1583
1584#ifdef CONFIG_NET_POLL_CONTROLLER
1585static void xennet_poll_controller(struct net_device *dev)
1586{
1587 /* Poll each queue */
1588 struct netfront_info *info = netdev_priv(dev);
1589 unsigned int num_queues = dev->real_num_tx_queues;
1590 unsigned int i;
1591
1592 if (info->broken)
1593 return;
1594
1595 for (i = 0; i < num_queues; ++i)
1596 xennet_interrupt(0, &info->queues[i]);
1597}
1598#endif
1599
1600#define NETBACK_XDP_HEADROOM_DISABLE 0
1601#define NETBACK_XDP_HEADROOM_ENABLE 1
1602
1603static int talk_to_netback_xdp(struct netfront_info *np, int xdp)
1604{
1605 int err;
1606 unsigned short headroom;
1607
1608 headroom = xdp ? XDP_PACKET_HEADROOM : 0;
1609 err = xenbus_printf(XBT_NIL, np->xbdev->nodename,
1610 "xdp-headroom", "%hu",
1611 headroom);
1612 if (err)
1613 pr_warn("Error writing xdp-headroom\n");
1614
1615 return err;
1616}
1617
1618static int xennet_xdp_set(struct net_device *dev, struct bpf_prog *prog,
1619 struct netlink_ext_ack *extack)
1620{
1621 unsigned long max_mtu = XEN_PAGE_SIZE - XDP_PACKET_HEADROOM;
1622 struct netfront_info *np = netdev_priv(dev);
1623 struct bpf_prog *old_prog;
1624 unsigned int i, err;
1625
1626 if (dev->mtu > max_mtu) {
1627 netdev_warn(dev, "XDP requires MTU less than %lu\n", max_mtu);
1628 return -EINVAL;
1629 }
1630
1631 if (!np->netback_has_xdp_headroom)
1632 return 0;
1633
1634 xenbus_switch_state(np->xbdev, XenbusStateReconfiguring);
1635
1636 err = talk_to_netback_xdp(np, prog ? NETBACK_XDP_HEADROOM_ENABLE :
1637 NETBACK_XDP_HEADROOM_DISABLE);
1638 if (err)
1639 return err;
1640
1641 /* avoid the race with XDP headroom adjustment */
1642 wait_event(module_wq,
1643 xenbus_read_driver_state(np->xbdev->otherend) ==
1644 XenbusStateReconfigured);
1645 np->netfront_xdp_enabled = true;
1646
1647 old_prog = rtnl_dereference(np->queues[0].xdp_prog);
1648
1649 if (prog)
1650 bpf_prog_add(prog, dev->real_num_tx_queues);
1651
1652 for (i = 0; i < dev->real_num_tx_queues; ++i)
1653 rcu_assign_pointer(np->queues[i].xdp_prog, prog);
1654
1655 if (old_prog)
1656 for (i = 0; i < dev->real_num_tx_queues; ++i)
1657 bpf_prog_put(old_prog);
1658
1659 xenbus_switch_state(np->xbdev, XenbusStateConnected);
1660
1661 return 0;
1662}
1663
1664static int xennet_xdp(struct net_device *dev, struct netdev_bpf *xdp)
1665{
1666 struct netfront_info *np = netdev_priv(dev);
1667
1668 if (np->broken)
1669 return -ENODEV;
1670
1671 switch (xdp->command) {
1672 case XDP_SETUP_PROG:
1673 return xennet_xdp_set(dev, xdp->prog, xdp->extack);
1674 default:
1675 return -EINVAL;
1676 }
1677}
1678
1679static const struct net_device_ops xennet_netdev_ops = {
1680 .ndo_uninit = xennet_uninit,
1681 .ndo_open = xennet_open,
1682 .ndo_stop = xennet_close,
1683 .ndo_start_xmit = xennet_start_xmit,
1684 .ndo_change_mtu = xennet_change_mtu,
1685 .ndo_get_stats64 = xennet_get_stats64,
1686 .ndo_set_mac_address = eth_mac_addr,
1687 .ndo_validate_addr = eth_validate_addr,
1688 .ndo_fix_features = xennet_fix_features,
1689 .ndo_set_features = xennet_set_features,
1690 .ndo_select_queue = xennet_select_queue,
1691 .ndo_bpf = xennet_xdp,
1692 .ndo_xdp_xmit = xennet_xdp_xmit,
1693#ifdef CONFIG_NET_POLL_CONTROLLER
1694 .ndo_poll_controller = xennet_poll_controller,
1695#endif
1696};
1697
1698static void xennet_free_netdev(struct net_device *netdev)
1699{
1700 struct netfront_info *np = netdev_priv(netdev);
1701
1702 free_percpu(np->rx_stats);
1703 free_percpu(np->tx_stats);
1704 free_netdev(netdev);
1705}
1706
1707static struct net_device *xennet_create_dev(struct xenbus_device *dev)
1708{
1709 int err;
1710 struct net_device *netdev;
1711 struct netfront_info *np;
1712
1713 netdev = alloc_etherdev_mq(sizeof(struct netfront_info), xennet_max_queues);
1714 if (!netdev)
1715 return ERR_PTR(-ENOMEM);
1716
1717 np = netdev_priv(netdev);
1718 np->xbdev = dev;
1719
1720 np->queues = NULL;
1721
1722 err = -ENOMEM;
1723 np->rx_stats = netdev_alloc_pcpu_stats(struct netfront_stats);
1724 if (np->rx_stats == NULL)
1725 goto exit;
1726 np->tx_stats = netdev_alloc_pcpu_stats(struct netfront_stats);
1727 if (np->tx_stats == NULL)
1728 goto exit;
1729
1730 netdev->netdev_ops = &xennet_netdev_ops;
1731
1732 netdev->features = NETIF_F_IP_CSUM | NETIF_F_RXCSUM |
1733 NETIF_F_GSO_ROBUST;
1734 netdev->hw_features = NETIF_F_SG |
1735 NETIF_F_IPV6_CSUM |
1736 NETIF_F_TSO | NETIF_F_TSO6;
1737
1738 /*
1739 * Assume that all hw features are available for now. This set
1740 * will be adjusted by the call to netdev_update_features() in
1741 * xennet_connect() which is the earliest point where we can
1742 * negotiate with the backend regarding supported features.
1743 */
1744 netdev->features |= netdev->hw_features;
1745 netdev->xdp_features = NETDEV_XDP_ACT_BASIC | NETDEV_XDP_ACT_REDIRECT |
1746 NETDEV_XDP_ACT_NDO_XMIT;
1747
1748 netdev->ethtool_ops = &xennet_ethtool_ops;
1749 netdev->min_mtu = ETH_MIN_MTU;
1750 netdev->max_mtu = XEN_NETIF_MAX_TX_SIZE;
1751 SET_NETDEV_DEV(netdev, &dev->dev);
1752
1753 np->netdev = netdev;
1754 np->netfront_xdp_enabled = false;
1755
1756 netif_carrier_off(netdev);
1757
1758 do {
1759 xenbus_switch_state(dev, XenbusStateInitialising);
1760 err = wait_event_timeout(module_wq,
1761 xenbus_read_driver_state(dev->otherend) !=
1762 XenbusStateClosed &&
1763 xenbus_read_driver_state(dev->otherend) !=
1764 XenbusStateUnknown, XENNET_TIMEOUT);
1765 } while (!err);
1766
1767 return netdev;
1768
1769 exit:
1770 xennet_free_netdev(netdev);
1771 return ERR_PTR(err);
1772}
1773
1774/*
1775 * Entry point to this code when a new device is created. Allocate the basic
1776 * structures and the ring buffers for communication with the backend, and
1777 * inform the backend of the appropriate details for those.
1778 */
1779static int netfront_probe(struct xenbus_device *dev,
1780 const struct xenbus_device_id *id)
1781{
1782 int err;
1783 struct net_device *netdev;
1784 struct netfront_info *info;
1785
1786 netdev = xennet_create_dev(dev);
1787 if (IS_ERR(netdev)) {
1788 err = PTR_ERR(netdev);
1789 xenbus_dev_fatal(dev, err, "creating netdev");
1790 return err;
1791 }
1792
1793 info = netdev_priv(netdev);
1794 dev_set_drvdata(&dev->dev, info);
1795#ifdef CONFIG_SYSFS
1796 info->netdev->sysfs_groups[0] = &xennet_dev_group;
1797#endif
1798
1799 return 0;
1800}
1801
1802static void xennet_end_access(int ref, void *page)
1803{
1804 /* This frees the page as a side-effect */
1805 if (ref != INVALID_GRANT_REF)
1806 gnttab_end_foreign_access(ref, virt_to_page(page));
1807}
1808
1809static void xennet_disconnect_backend(struct netfront_info *info)
1810{
1811 unsigned int i = 0;
1812 unsigned int num_queues = info->netdev->real_num_tx_queues;
1813
1814 netif_carrier_off(info->netdev);
1815
1816 for (i = 0; i < num_queues && info->queues; ++i) {
1817 struct netfront_queue *queue = &info->queues[i];
1818
1819 del_timer_sync(&queue->rx_refill_timer);
1820
1821 if (queue->tx_irq && (queue->tx_irq == queue->rx_irq))
1822 unbind_from_irqhandler(queue->tx_irq, queue);
1823 if (queue->tx_irq && (queue->tx_irq != queue->rx_irq)) {
1824 unbind_from_irqhandler(queue->tx_irq, queue);
1825 unbind_from_irqhandler(queue->rx_irq, queue);
1826 }
1827 queue->tx_evtchn = queue->rx_evtchn = 0;
1828 queue->tx_irq = queue->rx_irq = 0;
1829
1830 if (netif_running(info->netdev))
1831 napi_synchronize(&queue->napi);
1832
1833 xennet_release_tx_bufs(queue);
1834 xennet_release_rx_bufs(queue);
1835 gnttab_free_grant_references(queue->gref_tx_head);
1836 gnttab_free_grant_references(queue->gref_rx_head);
1837
1838 /* End access and free the pages */
1839 xennet_end_access(queue->tx_ring_ref, queue->tx.sring);
1840 xennet_end_access(queue->rx_ring_ref, queue->rx.sring);
1841
1842 queue->tx_ring_ref = INVALID_GRANT_REF;
1843 queue->rx_ring_ref = INVALID_GRANT_REF;
1844 queue->tx.sring = NULL;
1845 queue->rx.sring = NULL;
1846
1847 page_pool_destroy(queue->page_pool);
1848 }
1849}
1850
1851/*
1852 * We are reconnecting to the backend, due to a suspend/resume, or a backend
1853 * driver restart. We tear down our netif structure and recreate it, but
1854 * leave the device-layer structures intact so that this is transparent to the
1855 * rest of the kernel.
1856 */
1857static int netfront_resume(struct xenbus_device *dev)
1858{
1859 struct netfront_info *info = dev_get_drvdata(&dev->dev);
1860
1861 dev_dbg(&dev->dev, "%s\n", dev->nodename);
1862
1863 netif_tx_lock_bh(info->netdev);
1864 netif_device_detach(info->netdev);
1865 netif_tx_unlock_bh(info->netdev);
1866
1867 xennet_disconnect_backend(info);
1868
1869 rtnl_lock();
1870 if (info->queues)
1871 xennet_destroy_queues(info);
1872 rtnl_unlock();
1873
1874 return 0;
1875}
1876
1877static int xen_net_read_mac(struct xenbus_device *dev, u8 mac[])
1878{
1879 char *s, *e, *macstr;
1880 int i;
1881
1882 macstr = s = xenbus_read(XBT_NIL, dev->nodename, "mac", NULL);
1883 if (IS_ERR(macstr))
1884 return PTR_ERR(macstr);
1885
1886 for (i = 0; i < ETH_ALEN; i++) {
1887 mac[i] = simple_strtoul(s, &e, 16);
1888 if ((s == e) || (*e != ((i == ETH_ALEN-1) ? '\0' : ':'))) {
1889 kfree(macstr);
1890 return -ENOENT;
1891 }
1892 s = e+1;
1893 }
1894
1895 kfree(macstr);
1896 return 0;
1897}
1898
1899static int setup_netfront_single(struct netfront_queue *queue)
1900{
1901 int err;
1902
1903 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->tx_evtchn);
1904 if (err < 0)
1905 goto fail;
1906
1907 err = bind_evtchn_to_irqhandler_lateeoi(queue->tx_evtchn,
1908 xennet_interrupt, 0,
1909 queue->info->netdev->name,
1910 queue);
1911 if (err < 0)
1912 goto bind_fail;
1913 queue->rx_evtchn = queue->tx_evtchn;
1914 queue->rx_irq = queue->tx_irq = err;
1915
1916 return 0;
1917
1918bind_fail:
1919 xenbus_free_evtchn(queue->info->xbdev, queue->tx_evtchn);
1920 queue->tx_evtchn = 0;
1921fail:
1922 return err;
1923}
1924
1925static int setup_netfront_split(struct netfront_queue *queue)
1926{
1927 int err;
1928
1929 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->tx_evtchn);
1930 if (err < 0)
1931 goto fail;
1932 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->rx_evtchn);
1933 if (err < 0)
1934 goto alloc_rx_evtchn_fail;
1935
1936 snprintf(queue->tx_irq_name, sizeof(queue->tx_irq_name),
1937 "%s-tx", queue->name);
1938 err = bind_evtchn_to_irqhandler_lateeoi(queue->tx_evtchn,
1939 xennet_tx_interrupt, 0,
1940 queue->tx_irq_name, queue);
1941 if (err < 0)
1942 goto bind_tx_fail;
1943 queue->tx_irq = err;
1944
1945 snprintf(queue->rx_irq_name, sizeof(queue->rx_irq_name),
1946 "%s-rx", queue->name);
1947 err = bind_evtchn_to_irqhandler_lateeoi(queue->rx_evtchn,
1948 xennet_rx_interrupt, 0,
1949 queue->rx_irq_name, queue);
1950 if (err < 0)
1951 goto bind_rx_fail;
1952 queue->rx_irq = err;
1953
1954 return 0;
1955
1956bind_rx_fail:
1957 unbind_from_irqhandler(queue->tx_irq, queue);
1958 queue->tx_irq = 0;
1959bind_tx_fail:
1960 xenbus_free_evtchn(queue->info->xbdev, queue->rx_evtchn);
1961 queue->rx_evtchn = 0;
1962alloc_rx_evtchn_fail:
1963 xenbus_free_evtchn(queue->info->xbdev, queue->tx_evtchn);
1964 queue->tx_evtchn = 0;
1965fail:
1966 return err;
1967}
1968
1969static int setup_netfront(struct xenbus_device *dev,
1970 struct netfront_queue *queue, unsigned int feature_split_evtchn)
1971{
1972 struct xen_netif_tx_sring *txs;
1973 struct xen_netif_rx_sring *rxs;
1974 int err;
1975
1976 queue->tx_ring_ref = INVALID_GRANT_REF;
1977 queue->rx_ring_ref = INVALID_GRANT_REF;
1978 queue->rx.sring = NULL;
1979 queue->tx.sring = NULL;
1980
1981 err = xenbus_setup_ring(dev, GFP_NOIO | __GFP_HIGH, (void **)&txs,
1982 1, &queue->tx_ring_ref);
1983 if (err)
1984 goto fail;
1985
1986 XEN_FRONT_RING_INIT(&queue->tx, txs, XEN_PAGE_SIZE);
1987
1988 err = xenbus_setup_ring(dev, GFP_NOIO | __GFP_HIGH, (void **)&rxs,
1989 1, &queue->rx_ring_ref);
1990 if (err)
1991 goto fail;
1992
1993 XEN_FRONT_RING_INIT(&queue->rx, rxs, XEN_PAGE_SIZE);
1994
1995 if (feature_split_evtchn)
1996 err = setup_netfront_split(queue);
1997 /* setup single event channel if
1998 * a) feature-split-event-channels == 0
1999 * b) feature-split-event-channels == 1 but failed to setup
2000 */
2001 if (!feature_split_evtchn || err)
2002 err = setup_netfront_single(queue);
2003
2004 if (err)
2005 goto fail;
2006
2007 return 0;
2008
2009 fail:
2010 xenbus_teardown_ring((void **)&queue->rx.sring, 1, &queue->rx_ring_ref);
2011 xenbus_teardown_ring((void **)&queue->tx.sring, 1, &queue->tx_ring_ref);
2012
2013 return err;
2014}
2015
2016/* Queue-specific initialisation
2017 * This used to be done in xennet_create_dev() but must now
2018 * be run per-queue.
2019 */
2020static int xennet_init_queue(struct netfront_queue *queue)
2021{
2022 unsigned short i;
2023 int err = 0;
2024 char *devid;
2025
2026 spin_lock_init(&queue->tx_lock);
2027 spin_lock_init(&queue->rx_lock);
2028 spin_lock_init(&queue->rx_cons_lock);
2029
2030 timer_setup(&queue->rx_refill_timer, rx_refill_timeout, 0);
2031
2032 devid = strrchr(queue->info->xbdev->nodename, '/') + 1;
2033 snprintf(queue->name, sizeof(queue->name), "vif%s-q%u",
2034 devid, queue->id);
2035
2036 /* Initialise tx_skb_freelist as a free chain containing every entry. */
2037 queue->tx_skb_freelist = 0;
2038 queue->tx_pend_queue = TX_LINK_NONE;
2039 for (i = 0; i < NET_TX_RING_SIZE; i++) {
2040 queue->tx_link[i] = i + 1;
2041 queue->grant_tx_ref[i] = INVALID_GRANT_REF;
2042 queue->grant_tx_page[i] = NULL;
2043 }
2044 queue->tx_link[NET_TX_RING_SIZE - 1] = TX_LINK_NONE;
2045
2046 /* Clear out rx_skbs */
2047 for (i = 0; i < NET_RX_RING_SIZE; i++) {
2048 queue->rx_skbs[i] = NULL;
2049 queue->grant_rx_ref[i] = INVALID_GRANT_REF;
2050 }
2051
2052 /* A grant for every tx ring slot */
2053 if (gnttab_alloc_grant_references(NET_TX_RING_SIZE,
2054 &queue->gref_tx_head) < 0) {
2055 pr_alert("can't alloc tx grant refs\n");
2056 err = -ENOMEM;
2057 goto exit;
2058 }
2059
2060 /* A grant for every rx ring slot */
2061 if (gnttab_alloc_grant_references(NET_RX_RING_SIZE,
2062 &queue->gref_rx_head) < 0) {
2063 pr_alert("can't alloc rx grant refs\n");
2064 err = -ENOMEM;
2065 goto exit_free_tx;
2066 }
2067
2068 return 0;
2069
2070 exit_free_tx:
2071 gnttab_free_grant_references(queue->gref_tx_head);
2072 exit:
2073 return err;
2074}
2075
2076static int write_queue_xenstore_keys(struct netfront_queue *queue,
2077 struct xenbus_transaction *xbt, int write_hierarchical)
2078{
2079 /* Write the queue-specific keys into XenStore in the traditional
2080 * way for a single queue, or in a queue subkeys for multiple
2081 * queues.
2082 */
2083 struct xenbus_device *dev = queue->info->xbdev;
2084 int err;
2085 const char *message;
2086 char *path;
2087 size_t pathsize;
2088
2089 /* Choose the correct place to write the keys */
2090 if (write_hierarchical) {
2091 pathsize = strlen(dev->nodename) + 10;
2092 path = kzalloc(pathsize, GFP_KERNEL);
2093 if (!path) {
2094 err = -ENOMEM;
2095 message = "out of memory while writing ring references";
2096 goto error;
2097 }
2098 snprintf(path, pathsize, "%s/queue-%u",
2099 dev->nodename, queue->id);
2100 } else {
2101 path = (char *)dev->nodename;
2102 }
2103
2104 /* Write ring references */
2105 err = xenbus_printf(*xbt, path, "tx-ring-ref", "%u",
2106 queue->tx_ring_ref);
2107 if (err) {
2108 message = "writing tx-ring-ref";
2109 goto error;
2110 }
2111
2112 err = xenbus_printf(*xbt, path, "rx-ring-ref", "%u",
2113 queue->rx_ring_ref);
2114 if (err) {
2115 message = "writing rx-ring-ref";
2116 goto error;
2117 }
2118
2119 /* Write event channels; taking into account both shared
2120 * and split event channel scenarios.
2121 */
2122 if (queue->tx_evtchn == queue->rx_evtchn) {
2123 /* Shared event channel */
2124 err = xenbus_printf(*xbt, path,
2125 "event-channel", "%u", queue->tx_evtchn);
2126 if (err) {
2127 message = "writing event-channel";
2128 goto error;
2129 }
2130 } else {
2131 /* Split event channels */
2132 err = xenbus_printf(*xbt, path,
2133 "event-channel-tx", "%u", queue->tx_evtchn);
2134 if (err) {
2135 message = "writing event-channel-tx";
2136 goto error;
2137 }
2138
2139 err = xenbus_printf(*xbt, path,
2140 "event-channel-rx", "%u", queue->rx_evtchn);
2141 if (err) {
2142 message = "writing event-channel-rx";
2143 goto error;
2144 }
2145 }
2146
2147 if (write_hierarchical)
2148 kfree(path);
2149 return 0;
2150
2151error:
2152 if (write_hierarchical)
2153 kfree(path);
2154 xenbus_dev_fatal(dev, err, "%s", message);
2155 return err;
2156}
2157
2158
2159
2160static int xennet_create_page_pool(struct netfront_queue *queue)
2161{
2162 int err;
2163 struct page_pool_params pp_params = {
2164 .order = 0,
2165 .flags = 0,
2166 .pool_size = NET_RX_RING_SIZE,
2167 .nid = NUMA_NO_NODE,
2168 .dev = &queue->info->netdev->dev,
2169 .offset = XDP_PACKET_HEADROOM,
2170 .max_len = XEN_PAGE_SIZE - XDP_PACKET_HEADROOM,
2171 };
2172
2173 queue->page_pool = page_pool_create(&pp_params);
2174 if (IS_ERR(queue->page_pool)) {
2175 err = PTR_ERR(queue->page_pool);
2176 queue->page_pool = NULL;
2177 return err;
2178 }
2179
2180 err = xdp_rxq_info_reg(&queue->xdp_rxq, queue->info->netdev,
2181 queue->id, 0);
2182 if (err) {
2183 netdev_err(queue->info->netdev, "xdp_rxq_info_reg failed\n");
2184 goto err_free_pp;
2185 }
2186
2187 err = xdp_rxq_info_reg_mem_model(&queue->xdp_rxq,
2188 MEM_TYPE_PAGE_POOL, queue->page_pool);
2189 if (err) {
2190 netdev_err(queue->info->netdev, "xdp_rxq_info_reg_mem_model failed\n");
2191 goto err_unregister_rxq;
2192 }
2193 return 0;
2194
2195err_unregister_rxq:
2196 xdp_rxq_info_unreg(&queue->xdp_rxq);
2197err_free_pp:
2198 page_pool_destroy(queue->page_pool);
2199 queue->page_pool = NULL;
2200 return err;
2201}
2202
2203static int xennet_create_queues(struct netfront_info *info,
2204 unsigned int *num_queues)
2205{
2206 unsigned int i;
2207 int ret;
2208
2209 info->queues = kcalloc(*num_queues, sizeof(struct netfront_queue),
2210 GFP_KERNEL);
2211 if (!info->queues)
2212 return -ENOMEM;
2213
2214 for (i = 0; i < *num_queues; i++) {
2215 struct netfront_queue *queue = &info->queues[i];
2216
2217 queue->id = i;
2218 queue->info = info;
2219
2220 ret = xennet_init_queue(queue);
2221 if (ret < 0) {
2222 dev_warn(&info->xbdev->dev,
2223 "only created %d queues\n", i);
2224 *num_queues = i;
2225 break;
2226 }
2227
2228 /* use page pool recycling instead of buddy allocator */
2229 ret = xennet_create_page_pool(queue);
2230 if (ret < 0) {
2231 dev_err(&info->xbdev->dev, "can't allocate page pool\n");
2232 *num_queues = i;
2233 return ret;
2234 }
2235
2236 netif_napi_add(queue->info->netdev, &queue->napi, xennet_poll);
2237 if (netif_running(info->netdev))
2238 napi_enable(&queue->napi);
2239 }
2240
2241 netif_set_real_num_tx_queues(info->netdev, *num_queues);
2242
2243 if (*num_queues == 0) {
2244 dev_err(&info->xbdev->dev, "no queues\n");
2245 return -EINVAL;
2246 }
2247 return 0;
2248}
2249
2250/* Common code used when first setting up, and when resuming. */
2251static int talk_to_netback(struct xenbus_device *dev,
2252 struct netfront_info *info)
2253{
2254 const char *message;
2255 struct xenbus_transaction xbt;
2256 int err;
2257 unsigned int feature_split_evtchn;
2258 unsigned int i = 0;
2259 unsigned int max_queues = 0;
2260 struct netfront_queue *queue = NULL;
2261 unsigned int num_queues = 1;
2262 u8 addr[ETH_ALEN];
2263
2264 info->netdev->irq = 0;
2265
2266 /* Check if backend is trusted. */
2267 info->bounce = !xennet_trusted ||
2268 !xenbus_read_unsigned(dev->nodename, "trusted", 1);
2269
2270 /* Check if backend supports multiple queues */
2271 max_queues = xenbus_read_unsigned(info->xbdev->otherend,
2272 "multi-queue-max-queues", 1);
2273 num_queues = min(max_queues, xennet_max_queues);
2274
2275 /* Check feature-split-event-channels */
2276 feature_split_evtchn = xenbus_read_unsigned(info->xbdev->otherend,
2277 "feature-split-event-channels", 0);
2278
2279 /* Read mac addr. */
2280 err = xen_net_read_mac(dev, addr);
2281 if (err) {
2282 xenbus_dev_fatal(dev, err, "parsing %s/mac", dev->nodename);
2283 goto out_unlocked;
2284 }
2285 eth_hw_addr_set(info->netdev, addr);
2286
2287 info->netback_has_xdp_headroom = xenbus_read_unsigned(info->xbdev->otherend,
2288 "feature-xdp-headroom", 0);
2289 if (info->netback_has_xdp_headroom) {
2290 /* set the current xen-netfront xdp state */
2291 err = talk_to_netback_xdp(info, info->netfront_xdp_enabled ?
2292 NETBACK_XDP_HEADROOM_ENABLE :
2293 NETBACK_XDP_HEADROOM_DISABLE);
2294 if (err)
2295 goto out_unlocked;
2296 }
2297
2298 rtnl_lock();
2299 if (info->queues)
2300 xennet_destroy_queues(info);
2301
2302 /* For the case of a reconnect reset the "broken" indicator. */
2303 info->broken = false;
2304
2305 err = xennet_create_queues(info, &num_queues);
2306 if (err < 0) {
2307 xenbus_dev_fatal(dev, err, "creating queues");
2308 kfree(info->queues);
2309 info->queues = NULL;
2310 goto out;
2311 }
2312 rtnl_unlock();
2313
2314 /* Create shared ring, alloc event channel -- for each queue */
2315 for (i = 0; i < num_queues; ++i) {
2316 queue = &info->queues[i];
2317 err = setup_netfront(dev, queue, feature_split_evtchn);
2318 if (err)
2319 goto destroy_ring;
2320 }
2321
2322again:
2323 err = xenbus_transaction_start(&xbt);
2324 if (err) {
2325 xenbus_dev_fatal(dev, err, "starting transaction");
2326 goto destroy_ring;
2327 }
2328
2329 if (xenbus_exists(XBT_NIL,
2330 info->xbdev->otherend, "multi-queue-max-queues")) {
2331 /* Write the number of queues */
2332 err = xenbus_printf(xbt, dev->nodename,
2333 "multi-queue-num-queues", "%u", num_queues);
2334 if (err) {
2335 message = "writing multi-queue-num-queues";
2336 goto abort_transaction_no_dev_fatal;
2337 }
2338 }
2339
2340 if (num_queues == 1) {
2341 err = write_queue_xenstore_keys(&info->queues[0], &xbt, 0); /* flat */
2342 if (err)
2343 goto abort_transaction_no_dev_fatal;
2344 } else {
2345 /* Write the keys for each queue */
2346 for (i = 0; i < num_queues; ++i) {
2347 queue = &info->queues[i];
2348 err = write_queue_xenstore_keys(queue, &xbt, 1); /* hierarchical */
2349 if (err)
2350 goto abort_transaction_no_dev_fatal;
2351 }
2352 }
2353
2354 /* The remaining keys are not queue-specific */
2355 err = xenbus_printf(xbt, dev->nodename, "request-rx-copy", "%u",
2356 1);
2357 if (err) {
2358 message = "writing request-rx-copy";
2359 goto abort_transaction;
2360 }
2361
2362 err = xenbus_printf(xbt, dev->nodename, "feature-rx-notify", "%d", 1);
2363 if (err) {
2364 message = "writing feature-rx-notify";
2365 goto abort_transaction;
2366 }
2367
2368 err = xenbus_printf(xbt, dev->nodename, "feature-sg", "%d", 1);
2369 if (err) {
2370 message = "writing feature-sg";
2371 goto abort_transaction;
2372 }
2373
2374 err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv4", "%d", 1);
2375 if (err) {
2376 message = "writing feature-gso-tcpv4";
2377 goto abort_transaction;
2378 }
2379
2380 err = xenbus_write(xbt, dev->nodename, "feature-gso-tcpv6", "1");
2381 if (err) {
2382 message = "writing feature-gso-tcpv6";
2383 goto abort_transaction;
2384 }
2385
2386 err = xenbus_write(xbt, dev->nodename, "feature-ipv6-csum-offload",
2387 "1");
2388 if (err) {
2389 message = "writing feature-ipv6-csum-offload";
2390 goto abort_transaction;
2391 }
2392
2393 err = xenbus_transaction_end(xbt, 0);
2394 if (err) {
2395 if (err == -EAGAIN)
2396 goto again;
2397 xenbus_dev_fatal(dev, err, "completing transaction");
2398 goto destroy_ring;
2399 }
2400
2401 return 0;
2402
2403 abort_transaction:
2404 xenbus_dev_fatal(dev, err, "%s", message);
2405abort_transaction_no_dev_fatal:
2406 xenbus_transaction_end(xbt, 1);
2407 destroy_ring:
2408 xennet_disconnect_backend(info);
2409 rtnl_lock();
2410 xennet_destroy_queues(info);
2411 out:
2412 rtnl_unlock();
2413out_unlocked:
2414 device_unregister(&dev->dev);
2415 return err;
2416}
2417
2418static int xennet_connect(struct net_device *dev)
2419{
2420 struct netfront_info *np = netdev_priv(dev);
2421 unsigned int num_queues = 0;
2422 int err;
2423 unsigned int j = 0;
2424 struct netfront_queue *queue = NULL;
2425
2426 if (!xenbus_read_unsigned(np->xbdev->otherend, "feature-rx-copy", 0)) {
2427 dev_info(&dev->dev,
2428 "backend does not support copying receive path\n");
2429 return -ENODEV;
2430 }
2431
2432 err = talk_to_netback(np->xbdev, np);
2433 if (err)
2434 return err;
2435 if (np->netback_has_xdp_headroom)
2436 pr_info("backend supports XDP headroom\n");
2437 if (np->bounce)
2438 dev_info(&np->xbdev->dev,
2439 "bouncing transmitted data to zeroed pages\n");
2440
2441 /* talk_to_netback() sets the correct number of queues */
2442 num_queues = dev->real_num_tx_queues;
2443
2444 if (dev->reg_state == NETREG_UNINITIALIZED) {
2445 err = register_netdev(dev);
2446 if (err) {
2447 pr_warn("%s: register_netdev err=%d\n", __func__, err);
2448 device_unregister(&np->xbdev->dev);
2449 return err;
2450 }
2451 }
2452
2453 rtnl_lock();
2454 netdev_update_features(dev);
2455 rtnl_unlock();
2456
2457 /*
2458 * All public and private state should now be sane. Get
2459 * ready to start sending and receiving packets and give the driver
2460 * domain a kick because we've probably just requeued some
2461 * packets.
2462 */
2463 netif_tx_lock_bh(np->netdev);
2464 netif_device_attach(np->netdev);
2465 netif_tx_unlock_bh(np->netdev);
2466
2467 netif_carrier_on(np->netdev);
2468 for (j = 0; j < num_queues; ++j) {
2469 queue = &np->queues[j];
2470
2471 notify_remote_via_irq(queue->tx_irq);
2472 if (queue->tx_irq != queue->rx_irq)
2473 notify_remote_via_irq(queue->rx_irq);
2474
2475 spin_lock_bh(&queue->rx_lock);
2476 xennet_alloc_rx_buffers(queue);
2477 spin_unlock_bh(&queue->rx_lock);
2478 }
2479
2480 return 0;
2481}
2482
2483/*
2484 * Callback received when the backend's state changes.
2485 */
2486static void netback_changed(struct xenbus_device *dev,
2487 enum xenbus_state backend_state)
2488{
2489 struct netfront_info *np = dev_get_drvdata(&dev->dev);
2490 struct net_device *netdev = np->netdev;
2491
2492 dev_dbg(&dev->dev, "%s\n", xenbus_strstate(backend_state));
2493
2494 wake_up_all(&module_wq);
2495
2496 switch (backend_state) {
2497 case XenbusStateInitialising:
2498 case XenbusStateInitialised:
2499 case XenbusStateReconfiguring:
2500 case XenbusStateReconfigured:
2501 case XenbusStateUnknown:
2502 break;
2503
2504 case XenbusStateInitWait:
2505 if (dev->state != XenbusStateInitialising)
2506 break;
2507 if (xennet_connect(netdev) != 0)
2508 break;
2509 xenbus_switch_state(dev, XenbusStateConnected);
2510 break;
2511
2512 case XenbusStateConnected:
2513 netdev_notify_peers(netdev);
2514 break;
2515
2516 case XenbusStateClosed:
2517 if (dev->state == XenbusStateClosed)
2518 break;
2519 fallthrough; /* Missed the backend's CLOSING state */
2520 case XenbusStateClosing:
2521 xenbus_frontend_closed(dev);
2522 break;
2523 }
2524}
2525
2526static const struct xennet_stat {
2527 char name[ETH_GSTRING_LEN];
2528 u16 offset;
2529} xennet_stats[] = {
2530 {
2531 "rx_gso_checksum_fixup",
2532 offsetof(struct netfront_info, rx_gso_checksum_fixup)
2533 },
2534};
2535
2536static int xennet_get_sset_count(struct net_device *dev, int string_set)
2537{
2538 switch (string_set) {
2539 case ETH_SS_STATS:
2540 return ARRAY_SIZE(xennet_stats);
2541 default:
2542 return -EINVAL;
2543 }
2544}
2545
2546static void xennet_get_ethtool_stats(struct net_device *dev,
2547 struct ethtool_stats *stats, u64 * data)
2548{
2549 void *np = netdev_priv(dev);
2550 int i;
2551
2552 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++)
2553 data[i] = atomic_read((atomic_t *)(np + xennet_stats[i].offset));
2554}
2555
2556static void xennet_get_strings(struct net_device *dev, u32 stringset, u8 * data)
2557{
2558 int i;
2559
2560 switch (stringset) {
2561 case ETH_SS_STATS:
2562 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++)
2563 memcpy(data + i * ETH_GSTRING_LEN,
2564 xennet_stats[i].name, ETH_GSTRING_LEN);
2565 break;
2566 }
2567}
2568
2569static const struct ethtool_ops xennet_ethtool_ops =
2570{
2571 .get_link = ethtool_op_get_link,
2572
2573 .get_sset_count = xennet_get_sset_count,
2574 .get_ethtool_stats = xennet_get_ethtool_stats,
2575 .get_strings = xennet_get_strings,
2576 .get_ts_info = ethtool_op_get_ts_info,
2577};
2578
2579#ifdef CONFIG_SYSFS
2580static ssize_t show_rxbuf(struct device *dev,
2581 struct device_attribute *attr, char *buf)
2582{
2583 return sprintf(buf, "%lu\n", NET_RX_RING_SIZE);
2584}
2585
2586static ssize_t store_rxbuf(struct device *dev,
2587 struct device_attribute *attr,
2588 const char *buf, size_t len)
2589{
2590 char *endp;
2591
2592 if (!capable(CAP_NET_ADMIN))
2593 return -EPERM;
2594
2595 simple_strtoul(buf, &endp, 0);
2596 if (endp == buf)
2597 return -EBADMSG;
2598
2599 /* rxbuf_min and rxbuf_max are no longer configurable. */
2600
2601 return len;
2602}
2603
2604static DEVICE_ATTR(rxbuf_min, 0644, show_rxbuf, store_rxbuf);
2605static DEVICE_ATTR(rxbuf_max, 0644, show_rxbuf, store_rxbuf);
2606static DEVICE_ATTR(rxbuf_cur, 0444, show_rxbuf, NULL);
2607
2608static struct attribute *xennet_dev_attrs[] = {
2609 &dev_attr_rxbuf_min.attr,
2610 &dev_attr_rxbuf_max.attr,
2611 &dev_attr_rxbuf_cur.attr,
2612 NULL
2613};
2614
2615static const struct attribute_group xennet_dev_group = {
2616 .attrs = xennet_dev_attrs
2617};
2618#endif /* CONFIG_SYSFS */
2619
2620static void xennet_bus_close(struct xenbus_device *dev)
2621{
2622 int ret;
2623
2624 if (xenbus_read_driver_state(dev->otherend) == XenbusStateClosed)
2625 return;
2626 do {
2627 xenbus_switch_state(dev, XenbusStateClosing);
2628 ret = wait_event_timeout(module_wq,
2629 xenbus_read_driver_state(dev->otherend) ==
2630 XenbusStateClosing ||
2631 xenbus_read_driver_state(dev->otherend) ==
2632 XenbusStateClosed ||
2633 xenbus_read_driver_state(dev->otherend) ==
2634 XenbusStateUnknown,
2635 XENNET_TIMEOUT);
2636 } while (!ret);
2637
2638 if (xenbus_read_driver_state(dev->otherend) == XenbusStateClosed)
2639 return;
2640
2641 do {
2642 xenbus_switch_state(dev, XenbusStateClosed);
2643 ret = wait_event_timeout(module_wq,
2644 xenbus_read_driver_state(dev->otherend) ==
2645 XenbusStateClosed ||
2646 xenbus_read_driver_state(dev->otherend) ==
2647 XenbusStateUnknown,
2648 XENNET_TIMEOUT);
2649 } while (!ret);
2650}
2651
2652static void xennet_remove(struct xenbus_device *dev)
2653{
2654 struct netfront_info *info = dev_get_drvdata(&dev->dev);
2655
2656 xennet_bus_close(dev);
2657 xennet_disconnect_backend(info);
2658
2659 if (info->netdev->reg_state == NETREG_REGISTERED)
2660 unregister_netdev(info->netdev);
2661
2662 if (info->queues) {
2663 rtnl_lock();
2664 xennet_destroy_queues(info);
2665 rtnl_unlock();
2666 }
2667 xennet_free_netdev(info->netdev);
2668}
2669
2670static const struct xenbus_device_id netfront_ids[] = {
2671 { "vif" },
2672 { "" }
2673};
2674
2675static struct xenbus_driver netfront_driver = {
2676 .ids = netfront_ids,
2677 .probe = netfront_probe,
2678 .remove = xennet_remove,
2679 .resume = netfront_resume,
2680 .otherend_changed = netback_changed,
2681};
2682
2683static int __init netif_init(void)
2684{
2685 if (!xen_domain())
2686 return -ENODEV;
2687
2688 if (!xen_has_pv_nic_devices())
2689 return -ENODEV;
2690
2691 pr_info("Initialising Xen virtual ethernet driver\n");
2692
2693 /* Allow as many queues as there are CPUs inut max. 8 if user has not
2694 * specified a value.
2695 */
2696 if (xennet_max_queues == 0)
2697 xennet_max_queues = min_t(unsigned int, MAX_QUEUES_DEFAULT,
2698 num_online_cpus());
2699
2700 return xenbus_register_frontend(&netfront_driver);
2701}
2702module_init(netif_init);
2703
2704
2705static void __exit netif_exit(void)
2706{
2707 xenbus_unregister_driver(&netfront_driver);
2708}
2709module_exit(netif_exit);
2710
2711MODULE_DESCRIPTION("Xen virtual network device frontend");
2712MODULE_LICENSE("GPL");
2713MODULE_ALIAS("xen:vif");
2714MODULE_ALIAS("xennet");