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Merge tag 'block-5.11-2021-01-10' of git://git.kernel.dk/linux-block
[linux/fpc-iii.git] / drivers / net / xen-netfront.c
blobb01848ef46493f9bc19a853b784896429cd5923b
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.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
64 static unsigned int xennet_max_queues;
65 module_param_named(max_queues, xennet_max_queues, uint, 0644);
66 MODULE_PARM_DESC(max_queues,
67 "Maximum number of queues per virtual interface");
68
69 #define XENNET_TIMEOUT (5 * HZ)
70
71 static const struct ethtool_ops xennet_ethtool_ops;
72
73 struct netfront_cb {
74 int pull_to;
75 };
76
77 #define NETFRONT_SKB_CB(skb) ((struct netfront_cb *)((skb)->cb))
78
79 #define RX_COPY_THRESHOLD 256
80
81 #define GRANT_INVALID_REF 0
82
83 #define NET_TX_RING_SIZE __CONST_RING_SIZE(xen_netif_tx, XEN_PAGE_SIZE)
84 #define NET_RX_RING_SIZE __CONST_RING_SIZE(xen_netif_rx, XEN_PAGE_SIZE)
85
86 /* Minimum number of Rx slots (includes slot for GSO metadata). */
87 #define NET_RX_SLOTS_MIN (XEN_NETIF_NR_SLOTS_MIN + 1)
88
89 /* Queue name is interface name with "-qNNN" appended */
90 #define QUEUE_NAME_SIZE (IFNAMSIZ + 6)
91
92 /* IRQ name is queue name with "-tx" or "-rx" appended */
93 #define IRQ_NAME_SIZE (QUEUE_NAME_SIZE + 3)
94
95 static DECLARE_WAIT_QUEUE_HEAD(module_wq);
96
97 struct netfront_stats {
98 u64 packets;
99 u64 bytes;
100 struct u64_stats_sync syncp;
101 };
102
103 struct netfront_info;
104
105 struct netfront_queue {
106 unsigned int id; /* Queue ID, 0-based */
107 char name[QUEUE_NAME_SIZE]; /* DEVNAME-qN */
108 struct netfront_info *info;
109
110 struct bpf_prog __rcu *xdp_prog;
111
112 struct napi_struct napi;
113
114 /* Split event channels support, tx_* == rx_* when using
115 * single event channel.
116 */
117 unsigned int tx_evtchn, rx_evtchn;
118 unsigned int tx_irq, rx_irq;
119 /* Only used when split event channels support is enabled */
120 char tx_irq_name[IRQ_NAME_SIZE]; /* DEVNAME-qN-tx */
121 char rx_irq_name[IRQ_NAME_SIZE]; /* DEVNAME-qN-rx */
122
123 spinlock_t tx_lock;
124 struct xen_netif_tx_front_ring tx;
125 int tx_ring_ref;
126
127 /*
128 * {tx,rx}_skbs store outstanding skbuffs. Free tx_skb entries
129 * are linked from tx_skb_freelist through skb_entry.link.
130 *
131 * NB. Freelist index entries are always going to be less than
132 * PAGE_OFFSET, whereas pointers to skbs will always be equal or
133 * greater than PAGE_OFFSET: we use this property to distinguish
134 * them.
135 */
136 union skb_entry {
137 struct sk_buff *skb;
138 unsigned long link;
139 } tx_skbs[NET_TX_RING_SIZE];
140 grant_ref_t gref_tx_head;
141 grant_ref_t grant_tx_ref[NET_TX_RING_SIZE];
142 struct page *grant_tx_page[NET_TX_RING_SIZE];
143 unsigned tx_skb_freelist;
144
145 spinlock_t rx_lock ____cacheline_aligned_in_smp;
146 struct xen_netif_rx_front_ring rx;
147 int rx_ring_ref;
148
149 struct timer_list rx_refill_timer;
150
151 struct sk_buff *rx_skbs[NET_RX_RING_SIZE];
152 grant_ref_t gref_rx_head;
153 grant_ref_t grant_rx_ref[NET_RX_RING_SIZE];
154
155 struct page_pool *page_pool;
156 struct xdp_rxq_info xdp_rxq;
157 };
158
159 struct netfront_info {
160 struct list_head list;
161 struct net_device *netdev;
162
163 struct xenbus_device *xbdev;
164
165 /* Multi-queue support */
166 struct netfront_queue *queues;
167
168 /* Statistics */
169 struct netfront_stats __percpu *rx_stats;
170 struct netfront_stats __percpu *tx_stats;
171
172 /* XDP state */
173 bool netback_has_xdp_headroom;
174 bool netfront_xdp_enabled;
175
176 atomic_t rx_gso_checksum_fixup;
177 };
178
179 struct netfront_rx_info {
180 struct xen_netif_rx_response rx;
181 struct xen_netif_extra_info extras[XEN_NETIF_EXTRA_TYPE_MAX - 1];
182 };
183
184 static void skb_entry_set_link(union skb_entry *list, unsigned short id)
185 {
186 list->link = id;
187 }
188
189 static int skb_entry_is_link(const union skb_entry *list)
190 {
191 BUILD_BUG_ON(sizeof(list->skb) != sizeof(list->link));
192 return (unsigned long)list->skb < PAGE_OFFSET;
193 }
194
195 /*
196 * Access macros for acquiring freeing slots in tx_skbs[].
197 */
198
199 static void add_id_to_freelist(unsigned *head, union skb_entry *list,
200 unsigned short id)
201 {
202 skb_entry_set_link(&list[id], *head);
203 *head = id;
204 }
205
206 static unsigned short get_id_from_freelist(unsigned *head,
207 union skb_entry *list)
208 {
209 unsigned int id = *head;
210 *head = list[id].link;
211 return id;
212 }
213
214 static int xennet_rxidx(RING_IDX idx)
215 {
216 return idx & (NET_RX_RING_SIZE - 1);
217 }
218
219 static struct sk_buff *xennet_get_rx_skb(struct netfront_queue *queue,
220 RING_IDX ri)
221 {
222 int i = xennet_rxidx(ri);
223 struct sk_buff *skb = queue->rx_skbs[i];
224 queue->rx_skbs[i] = NULL;
225 return skb;
226 }
227
228 static grant_ref_t xennet_get_rx_ref(struct netfront_queue *queue,
229 RING_IDX ri)
230 {
231 int i = xennet_rxidx(ri);
232 grant_ref_t ref = queue->grant_rx_ref[i];
233 queue->grant_rx_ref[i] = GRANT_INVALID_REF;
234 return ref;
235 }
236
237 #ifdef CONFIG_SYSFS
238 static const struct attribute_group xennet_dev_group;
239 #endif
240
241 static bool xennet_can_sg(struct net_device *dev)
242 {
243 return dev->features & NETIF_F_SG;
244 }
245
246
247 static void rx_refill_timeout(struct timer_list *t)
248 {
249 struct netfront_queue *queue = from_timer(queue, t, rx_refill_timer);
250 napi_schedule(&queue->napi);
251 }
252
253 static int netfront_tx_slot_available(struct netfront_queue *queue)
254 {
255 return (queue->tx.req_prod_pvt - queue->tx.rsp_cons) <
256 (NET_TX_RING_SIZE - XEN_NETIF_NR_SLOTS_MIN - 1);
257 }
258
259 static void xennet_maybe_wake_tx(struct netfront_queue *queue)
260 {
261 struct net_device *dev = queue->info->netdev;
262 struct netdev_queue *dev_queue = netdev_get_tx_queue(dev, queue->id);
263
264 if (unlikely(netif_tx_queue_stopped(dev_queue)) &&
265 netfront_tx_slot_available(queue) &&
266 likely(netif_running(dev)))
267 netif_tx_wake_queue(netdev_get_tx_queue(dev, queue->id));
268 }
269
270
271 static struct sk_buff *xennet_alloc_one_rx_buffer(struct netfront_queue *queue)
272 {
273 struct sk_buff *skb;
274 struct page *page;
275
276 skb = __netdev_alloc_skb(queue->info->netdev,
277 RX_COPY_THRESHOLD + NET_IP_ALIGN,
278 GFP_ATOMIC | __GFP_NOWARN);
279 if (unlikely(!skb))
280 return NULL;
281
282 page = page_pool_dev_alloc_pages(queue->page_pool);
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
289 /* Align ip header to a 16 bytes boundary */
290 skb_reserve(skb, NET_IP_ALIGN);
291 skb->dev = queue->info->netdev;
292
293 return skb;
294 }
295
296
297 static void xennet_alloc_rx_buffers(struct netfront_queue *queue)
298 {
299 RING_IDX req_prod = queue->rx.req_prod_pvt;
300 int notify;
301 int err = 0;
302
303 if (unlikely(!netif_carrier_ok(queue->info->netdev)))
304 return;
305
306 for (req_prod = queue->rx.req_prod_pvt;
307 req_prod - queue->rx.rsp_cons < NET_RX_RING_SIZE;
308 req_prod++) {
309 struct sk_buff *skb;
310 unsigned short id;
311 grant_ref_t ref;
312 struct page *page;
313 struct xen_netif_rx_request *req;
314
315 skb = xennet_alloc_one_rx_buffer(queue);
316 if (!skb) {
317 err = -ENOMEM;
318 break;
319 }
320
321 id = xennet_rxidx(req_prod);
322
323 BUG_ON(queue->rx_skbs[id]);
324 queue->rx_skbs[id] = skb;
325
326 ref = gnttab_claim_grant_reference(&queue->gref_rx_head);
327 WARN_ON_ONCE(IS_ERR_VALUE((unsigned long)(int)ref));
328 queue->grant_rx_ref[id] = ref;
329
330 page = skb_frag_page(&skb_shinfo(skb)->frags[0]);
331
332 req = RING_GET_REQUEST(&queue->rx, req_prod);
333 gnttab_page_grant_foreign_access_ref_one(ref,
334 queue->info->xbdev->otherend_id,
335 page,
336 0);
337 req->id = id;
338 req->gref = ref;
339 }
340
341 queue->rx.req_prod_pvt = req_prod;
342
343 /* Try again later if there are not enough requests or skb allocation
344 * failed.
345 * Enough requests is quantified as the sum of newly created slots and
346 * the unconsumed slots at the backend.
347 */
348 if (req_prod - queue->rx.rsp_cons < NET_RX_SLOTS_MIN ||
349 unlikely(err)) {
350 mod_timer(&queue->rx_refill_timer, jiffies + (HZ/10));
351 return;
352 }
353
354 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->rx, notify);
355 if (notify)
356 notify_remote_via_irq(queue->rx_irq);
357 }
358
359 static int xennet_open(struct net_device *dev)
360 {
361 struct netfront_info *np = netdev_priv(dev);
362 unsigned int num_queues = dev->real_num_tx_queues;
363 unsigned int i = 0;
364 struct netfront_queue *queue = NULL;
365
366 if (!np->queues)
367 return -ENODEV;
368
369 for (i = 0; i < num_queues; ++i) {
370 queue = &np->queues[i];
371 napi_enable(&queue->napi);
372
373 spin_lock_bh(&queue->rx_lock);
374 if (netif_carrier_ok(dev)) {
375 xennet_alloc_rx_buffers(queue);
376 queue->rx.sring->rsp_event = queue->rx.rsp_cons + 1;
377 if (RING_HAS_UNCONSUMED_RESPONSES(&queue->rx))
378 napi_schedule(&queue->napi);
379 }
380 spin_unlock_bh(&queue->rx_lock);
381 }
382
383 netif_tx_start_all_queues(dev);
384
385 return 0;
386 }
387
388 static void xennet_tx_buf_gc(struct netfront_queue *queue)
389 {
390 RING_IDX cons, prod;
391 unsigned short id;
392 struct sk_buff *skb;
393 bool more_to_do;
394
395 BUG_ON(!netif_carrier_ok(queue->info->netdev));
396
397 do {
398 prod = queue->tx.sring->rsp_prod;
399 rmb(); /* Ensure we see responses up to 'rp'. */
400
401 for (cons = queue->tx.rsp_cons; cons != prod; cons++) {
402 struct xen_netif_tx_response *txrsp;
403
404 txrsp = RING_GET_RESPONSE(&queue->tx, cons);
405 if (txrsp->status == XEN_NETIF_RSP_NULL)
406 continue;
407
408 id = txrsp->id;
409 skb = queue->tx_skbs[id].skb;
410 if (unlikely(gnttab_query_foreign_access(
411 queue->grant_tx_ref[id]) != 0)) {
412 pr_alert("%s: warning -- grant still in use by backend domain\n",
413 __func__);
414 BUG();
415 }
416 gnttab_end_foreign_access_ref(
417 queue->grant_tx_ref[id], GNTMAP_readonly);
418 gnttab_release_grant_reference(
419 &queue->gref_tx_head, queue->grant_tx_ref[id]);
420 queue->grant_tx_ref[id] = GRANT_INVALID_REF;
421 queue->grant_tx_page[id] = NULL;
422 add_id_to_freelist(&queue->tx_skb_freelist, queue->tx_skbs, id);
423 dev_kfree_skb_irq(skb);
424 }
425
426 queue->tx.rsp_cons = prod;
427
428 RING_FINAL_CHECK_FOR_RESPONSES(&queue->tx, more_to_do);
429 } while (more_to_do);
430
431 xennet_maybe_wake_tx(queue);
432 }
433
434 struct xennet_gnttab_make_txreq {
435 struct netfront_queue *queue;
436 struct sk_buff *skb;
437 struct page *page;
438 struct xen_netif_tx_request *tx; /* Last request */
439 unsigned int size;
440 };
441
442 static void xennet_tx_setup_grant(unsigned long gfn, unsigned int offset,
443 unsigned int len, void *data)
444 {
445 struct xennet_gnttab_make_txreq *info = data;
446 unsigned int id;
447 struct xen_netif_tx_request *tx;
448 grant_ref_t ref;
449 /* convenient aliases */
450 struct page *page = info->page;
451 struct netfront_queue *queue = info->queue;
452 struct sk_buff *skb = info->skb;
453
454 id = get_id_from_freelist(&queue->tx_skb_freelist, queue->tx_skbs);
455 tx = RING_GET_REQUEST(&queue->tx, queue->tx.req_prod_pvt++);
456 ref = gnttab_claim_grant_reference(&queue->gref_tx_head);
457 WARN_ON_ONCE(IS_ERR_VALUE((unsigned long)(int)ref));
458
459 gnttab_grant_foreign_access_ref(ref, queue->info->xbdev->otherend_id,
460 gfn, GNTMAP_readonly);
461
462 queue->tx_skbs[id].skb = skb;
463 queue->grant_tx_page[id] = page;
464 queue->grant_tx_ref[id] = ref;
465
466 tx->id = id;
467 tx->gref = ref;
468 tx->offset = offset;
469 tx->size = len;
470 tx->flags = 0;
471
472 info->tx = tx;
473 info->size += tx->size;
474 }
475
476 static struct xen_netif_tx_request *xennet_make_first_txreq(
477 struct netfront_queue *queue, struct sk_buff *skb,
478 struct page *page, unsigned int offset, unsigned int len)
479 {
480 struct xennet_gnttab_make_txreq info = {
481 .queue = queue,
482 .skb = skb,
483 .page = page,
484 .size = 0,
485 };
486
487 gnttab_for_one_grant(page, offset, len, xennet_tx_setup_grant, &info);
488
489 return info.tx;
490 }
491
492 static void xennet_make_one_txreq(unsigned long gfn, unsigned int offset,
493 unsigned int len, void *data)
494 {
495 struct xennet_gnttab_make_txreq *info = data;
496
497 info->tx->flags |= XEN_NETTXF_more_data;
498 skb_get(info->skb);
499 xennet_tx_setup_grant(gfn, offset, len, data);
500 }
501
502 static struct xen_netif_tx_request *xennet_make_txreqs(
503 struct netfront_queue *queue, struct xen_netif_tx_request *tx,
504 struct sk_buff *skb, struct page *page,
505 unsigned int offset, unsigned int len)
506 {
507 struct xennet_gnttab_make_txreq info = {
508 .queue = queue,
509 .skb = skb,
510 .tx = tx,
511 };
512
513 /* Skip unused frames from start of page */
514 page += offset >> PAGE_SHIFT;
515 offset &= ~PAGE_MASK;
516
517 while (len) {
518 info.page = page;
519 info.size = 0;
520
521 gnttab_foreach_grant_in_range(page, offset, len,
522 xennet_make_one_txreq,
523 &info);
524
525 page++;
526 offset = 0;
527 len -= info.size;
528 }
529
530 return info.tx;
531 }
532
533 /*
534 * Count how many ring slots are required to send this skb. Each frag
535 * might be a compound page.
536 */
537 static int xennet_count_skb_slots(struct sk_buff *skb)
538 {
539 int i, frags = skb_shinfo(skb)->nr_frags;
540 int slots;
541
542 slots = gnttab_count_grant(offset_in_page(skb->data),
543 skb_headlen(skb));
544
545 for (i = 0; i < frags; i++) {
546 skb_frag_t *frag = skb_shinfo(skb)->frags + i;
547 unsigned long size = skb_frag_size(frag);
548 unsigned long offset = skb_frag_off(frag);
549
550 /* Skip unused frames from start of page */
551 offset &= ~PAGE_MASK;
552
553 slots += gnttab_count_grant(offset, size);
554 }
555
556 return slots;
557 }
558
559 static u16 xennet_select_queue(struct net_device *dev, struct sk_buff *skb,
560 struct net_device *sb_dev)
561 {
562 unsigned int num_queues = dev->real_num_tx_queues;
563 u32 hash;
564 u16 queue_idx;
565
566 /* First, check if there is only one queue */
567 if (num_queues == 1) {
568 queue_idx = 0;
569 } else {
570 hash = skb_get_hash(skb);
571 queue_idx = hash % num_queues;
572 }
573
574 return queue_idx;
575 }
576
577 static int xennet_xdp_xmit_one(struct net_device *dev,
578 struct netfront_queue *queue,
579 struct xdp_frame *xdpf)
580 {
581 struct netfront_info *np = netdev_priv(dev);
582 struct netfront_stats *tx_stats = this_cpu_ptr(np->tx_stats);
583 int notify;
584
585 xennet_make_first_txreq(queue, NULL,
586 virt_to_page(xdpf->data),
587 offset_in_page(xdpf->data),
588 xdpf->len);
589
590 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->tx, notify);
591 if (notify)
592 notify_remote_via_irq(queue->tx_irq);
593
594 u64_stats_update_begin(&tx_stats->syncp);
595 tx_stats->bytes += xdpf->len;
596 tx_stats->packets++;
597 u64_stats_update_end(&tx_stats->syncp);
598
599 xennet_tx_buf_gc(queue);
600
601 return 0;
602 }
603
604 static int xennet_xdp_xmit(struct net_device *dev, int n,
605 struct xdp_frame **frames, u32 flags)
606 {
607 unsigned int num_queues = dev->real_num_tx_queues;
608 struct netfront_info *np = netdev_priv(dev);
609 struct netfront_queue *queue = NULL;
610 unsigned long irq_flags;
611 int drops = 0;
612 int i, err;
613
614 if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK))
615 return -EINVAL;
616
617 queue = &np->queues[smp_processor_id() % num_queues];
618
619 spin_lock_irqsave(&queue->tx_lock, irq_flags);
620 for (i = 0; i < n; i++) {
621 struct xdp_frame *xdpf = frames[i];
622
623 if (!xdpf)
624 continue;
625 err = xennet_xdp_xmit_one(dev, queue, xdpf);
626 if (err) {
627 xdp_return_frame_rx_napi(xdpf);
628 drops++;
629 }
630 }
631 spin_unlock_irqrestore(&queue->tx_lock, irq_flags);
632
633 return n - drops;
634 }
635
636
637 #define MAX_XEN_SKB_FRAGS (65536 / XEN_PAGE_SIZE + 1)
638
639 static netdev_tx_t xennet_start_xmit(struct sk_buff *skb, struct net_device *dev)
640 {
641 struct netfront_info *np = netdev_priv(dev);
642 struct netfront_stats *tx_stats = this_cpu_ptr(np->tx_stats);
643 struct xen_netif_tx_request *tx, *first_tx;
644 unsigned int i;
645 int notify;
646 int slots;
647 struct page *page;
648 unsigned int offset;
649 unsigned int len;
650 unsigned long flags;
651 struct netfront_queue *queue = NULL;
652 unsigned int num_queues = dev->real_num_tx_queues;
653 u16 queue_index;
654 struct sk_buff *nskb;
655
656 /* Drop the packet if no queues are set up */
657 if (num_queues < 1)
658 goto drop;
659 /* Determine which queue to transmit this SKB on */
660 queue_index = skb_get_queue_mapping(skb);
661 queue = &np->queues[queue_index];
662
663 /* If skb->len is too big for wire format, drop skb and alert
664 * user about misconfiguration.
665 */
666 if (unlikely(skb->len > XEN_NETIF_MAX_TX_SIZE)) {
667 net_alert_ratelimited(
668 "xennet: skb->len = %u, too big for wire format\n",
669 skb->len);
670 goto drop;
671 }
672
673 slots = xennet_count_skb_slots(skb);
674 if (unlikely(slots > MAX_XEN_SKB_FRAGS + 1)) {
675 net_dbg_ratelimited("xennet: skb rides the rocket: %d slots, %d bytes\n",
676 slots, skb->len);
677 if (skb_linearize(skb))
678 goto drop;
679 }
680
681 page = virt_to_page(skb->data);
682 offset = offset_in_page(skb->data);
683
684 /* The first req should be at least ETH_HLEN size or the packet will be
685 * dropped by netback.
686 */
687 if (unlikely(PAGE_SIZE - offset < ETH_HLEN)) {
688 nskb = skb_copy(skb, GFP_ATOMIC);
689 if (!nskb)
690 goto drop;
691 dev_consume_skb_any(skb);
692 skb = nskb;
693 page = virt_to_page(skb->data);
694 offset = offset_in_page(skb->data);
695 }
696
697 len = skb_headlen(skb);
698
699 spin_lock_irqsave(&queue->tx_lock, flags);
700
701 if (unlikely(!netif_carrier_ok(dev) ||
702 (slots > 1 && !xennet_can_sg(dev)) ||
703 netif_needs_gso(skb, netif_skb_features(skb)))) {
704 spin_unlock_irqrestore(&queue->tx_lock, flags);
705 goto drop;
706 }
707
708 /* First request for the linear area. */
709 first_tx = tx = xennet_make_first_txreq(queue, skb,
710 page, offset, len);
711 offset += tx->size;
712 if (offset == PAGE_SIZE) {
713 page++;
714 offset = 0;
715 }
716 len -= tx->size;
717
718 if (skb->ip_summed == CHECKSUM_PARTIAL)
719 /* local packet? */
720 tx->flags |= XEN_NETTXF_csum_blank | XEN_NETTXF_data_validated;
721 else if (skb->ip_summed == CHECKSUM_UNNECESSARY)
722 /* remote but checksummed. */
723 tx->flags |= XEN_NETTXF_data_validated;
724
725 /* Optional extra info after the first request. */
726 if (skb_shinfo(skb)->gso_size) {
727 struct xen_netif_extra_info *gso;
728
729 gso = (struct xen_netif_extra_info *)
730 RING_GET_REQUEST(&queue->tx, queue->tx.req_prod_pvt++);
731
732 tx->flags |= XEN_NETTXF_extra_info;
733
734 gso->u.gso.size = skb_shinfo(skb)->gso_size;
735 gso->u.gso.type = (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6) ?
736 XEN_NETIF_GSO_TYPE_TCPV6 :
737 XEN_NETIF_GSO_TYPE_TCPV4;
738 gso->u.gso.pad = 0;
739 gso->u.gso.features = 0;
740
741 gso->type = XEN_NETIF_EXTRA_TYPE_GSO;
742 gso->flags = 0;
743 }
744
745 /* Requests for the rest of the linear area. */
746 tx = xennet_make_txreqs(queue, tx, skb, page, offset, len);
747
748 /* Requests for all the frags. */
749 for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
750 skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
751 tx = xennet_make_txreqs(queue, tx, skb, skb_frag_page(frag),
752 skb_frag_off(frag),
753 skb_frag_size(frag));
754 }
755
756 /* First request has the packet length. */
757 first_tx->size = skb->len;
758
759 /* timestamp packet in software */
760 skb_tx_timestamp(skb);
761
762 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->tx, notify);
763 if (notify)
764 notify_remote_via_irq(queue->tx_irq);
765
766 u64_stats_update_begin(&tx_stats->syncp);
767 tx_stats->bytes += skb->len;
768 tx_stats->packets++;
769 u64_stats_update_end(&tx_stats->syncp);
770
771 /* Note: It is not safe to access skb after xennet_tx_buf_gc()! */
772 xennet_tx_buf_gc(queue);
773
774 if (!netfront_tx_slot_available(queue))
775 netif_tx_stop_queue(netdev_get_tx_queue(dev, queue->id));
776
777 spin_unlock_irqrestore(&queue->tx_lock, flags);
778
779 return NETDEV_TX_OK;
780
781 drop:
782 dev->stats.tx_dropped++;
783 dev_kfree_skb_any(skb);
784 return NETDEV_TX_OK;
785 }
786
787 static int xennet_close(struct net_device *dev)
788 {
789 struct netfront_info *np = netdev_priv(dev);
790 unsigned int num_queues = dev->real_num_tx_queues;
791 unsigned int i;
792 struct netfront_queue *queue;
793 netif_tx_stop_all_queues(np->netdev);
794 for (i = 0; i < num_queues; ++i) {
795 queue = &np->queues[i];
796 napi_disable(&queue->napi);
797 }
798 return 0;
799 }
800
801 static void xennet_move_rx_slot(struct netfront_queue *queue, struct sk_buff *skb,
802 grant_ref_t ref)
803 {
804 int new = xennet_rxidx(queue->rx.req_prod_pvt);
805
806 BUG_ON(queue->rx_skbs[new]);
807 queue->rx_skbs[new] = skb;
808 queue->grant_rx_ref[new] = ref;
809 RING_GET_REQUEST(&queue->rx, queue->rx.req_prod_pvt)->id = new;
810 RING_GET_REQUEST(&queue->rx, queue->rx.req_prod_pvt)->gref = ref;
811 queue->rx.req_prod_pvt++;
812 }
813
814 static int xennet_get_extras(struct netfront_queue *queue,
815 struct xen_netif_extra_info *extras,
816 RING_IDX rp)
817
818 {
819 struct xen_netif_extra_info *extra;
820 struct device *dev = &queue->info->netdev->dev;
821 RING_IDX cons = queue->rx.rsp_cons;
822 int err = 0;
823
824 do {
825 struct sk_buff *skb;
826 grant_ref_t ref;
827
828 if (unlikely(cons + 1 == rp)) {
829 if (net_ratelimit())
830 dev_warn(dev, "Missing extra info\n");
831 err = -EBADR;
832 break;
833 }
834
835 extra = (struct xen_netif_extra_info *)
836 RING_GET_RESPONSE(&queue->rx, ++cons);
837
838 if (unlikely(!extra->type ||
839 extra->type >= XEN_NETIF_EXTRA_TYPE_MAX)) {
840 if (net_ratelimit())
841 dev_warn(dev, "Invalid extra type: %d\n",
842 extra->type);
843 err = -EINVAL;
844 } else {
845 memcpy(&extras[extra->type - 1], extra,
846 sizeof(*extra));
847 }
848
849 skb = xennet_get_rx_skb(queue, cons);
850 ref = xennet_get_rx_ref(queue, cons);
851 xennet_move_rx_slot(queue, skb, ref);
852 } while (extra->flags & XEN_NETIF_EXTRA_FLAG_MORE);
853
854 queue->rx.rsp_cons = cons;
855 return err;
856 }
857
858 static u32 xennet_run_xdp(struct netfront_queue *queue, struct page *pdata,
859 struct xen_netif_rx_response *rx, struct bpf_prog *prog,
860 struct xdp_buff *xdp, bool *need_xdp_flush)
861 {
862 struct xdp_frame *xdpf;
863 u32 len = rx->status;
864 u32 act;
865 int err;
866
867 xdp->data_hard_start = page_address(pdata);
868 xdp->data = xdp->data_hard_start + XDP_PACKET_HEADROOM;
869 xdp_set_data_meta_invalid(xdp);
870 xdp->data_end = xdp->data + len;
871 xdp->rxq = &queue->xdp_rxq;
872 xdp->frame_sz = XEN_PAGE_SIZE - XDP_PACKET_HEADROOM;
873
874 act = bpf_prog_run_xdp(prog, xdp);
875 switch (act) {
876 case XDP_TX:
877 get_page(pdata);
878 xdpf = xdp_convert_buff_to_frame(xdp);
879 err = xennet_xdp_xmit(queue->info->netdev, 1, &xdpf, 0);
880 if (unlikely(err < 0))
881 trace_xdp_exception(queue->info->netdev, prog, act);
882 break;
883 case XDP_REDIRECT:
884 get_page(pdata);
885 err = xdp_do_redirect(queue->info->netdev, xdp, prog);
886 *need_xdp_flush = true;
887 if (unlikely(err))
888 trace_xdp_exception(queue->info->netdev, prog, act);
889 break;
890 case XDP_PASS:
891 case XDP_DROP:
892 break;
893
894 case XDP_ABORTED:
895 trace_xdp_exception(queue->info->netdev, prog, act);
896 break;
897
898 default:
899 bpf_warn_invalid_xdp_action(act);
900 }
901
902 return act;
903 }
904
905 static int xennet_get_responses(struct netfront_queue *queue,
906 struct netfront_rx_info *rinfo, RING_IDX rp,
907 struct sk_buff_head *list,
908 bool *need_xdp_flush)
909 {
910 struct xen_netif_rx_response *rx = &rinfo->rx;
911 int max = XEN_NETIF_NR_SLOTS_MIN + (rx->status <= RX_COPY_THRESHOLD);
912 RING_IDX cons = queue->rx.rsp_cons;
913 struct sk_buff *skb = xennet_get_rx_skb(queue, cons);
914 struct xen_netif_extra_info *extras = rinfo->extras;
915 grant_ref_t ref = xennet_get_rx_ref(queue, cons);
916 struct device *dev = &queue->info->netdev->dev;
917 struct bpf_prog *xdp_prog;
918 struct xdp_buff xdp;
919 unsigned long ret;
920 int slots = 1;
921 int err = 0;
922 u32 verdict;
923
924 if (rx->flags & XEN_NETRXF_extra_info) {
925 err = xennet_get_extras(queue, extras, rp);
926 if (!err) {
927 if (extras[XEN_NETIF_EXTRA_TYPE_XDP - 1].type) {
928 struct xen_netif_extra_info *xdp;
929
930 xdp = &extras[XEN_NETIF_EXTRA_TYPE_XDP - 1];
931 rx->offset = xdp->u.xdp.headroom;
932 }
933 }
934 cons = queue->rx.rsp_cons;
935 }
936
937 for (;;) {
938 if (unlikely(rx->status < 0 ||
939 rx->offset + rx->status > XEN_PAGE_SIZE)) {
940 if (net_ratelimit())
941 dev_warn(dev, "rx->offset: %u, size: %d\n",
942 rx->offset, rx->status);
943 xennet_move_rx_slot(queue, skb, ref);
944 err = -EINVAL;
945 goto next;
946 }
947
948 /*
949 * This definitely indicates a bug, either in this driver or in
950 * the backend driver. In future this should flag the bad
951 * situation to the system controller to reboot the backend.
952 */
953 if (ref == GRANT_INVALID_REF) {
954 if (net_ratelimit())
955 dev_warn(dev, "Bad rx response id %d.\n",
956 rx->id);
957 err = -EINVAL;
958 goto next;
959 }
960
961 ret = gnttab_end_foreign_access_ref(ref, 0);
962 BUG_ON(!ret);
963
964 gnttab_release_grant_reference(&queue->gref_rx_head, ref);
965
966 rcu_read_lock();
967 xdp_prog = rcu_dereference(queue->xdp_prog);
968 if (xdp_prog) {
969 if (!(rx->flags & XEN_NETRXF_more_data)) {
970 /* currently only a single page contains data */
971 verdict = xennet_run_xdp(queue,
972 skb_frag_page(&skb_shinfo(skb)->frags[0]),
973 rx, xdp_prog, &xdp, need_xdp_flush);
974 if (verdict != XDP_PASS)
975 err = -EINVAL;
976 } else {
977 /* drop the frame */
978 err = -EINVAL;
979 }
980 }
981 rcu_read_unlock();
982 next:
983 __skb_queue_tail(list, skb);
984 if (!(rx->flags & XEN_NETRXF_more_data))
985 break;
986
987 if (cons + slots == rp) {
988 if (net_ratelimit())
989 dev_warn(dev, "Need more slots\n");
990 err = -ENOENT;
991 break;
992 }
993
994 rx = RING_GET_RESPONSE(&queue->rx, cons + slots);
995 skb = xennet_get_rx_skb(queue, cons + slots);
996 ref = xennet_get_rx_ref(queue, cons + slots);
997 slots++;
998 }
999
1000 if (unlikely(slots > max)) {
1001 if (net_ratelimit())
1002 dev_warn(dev, "Too many slots\n");
1003 err = -E2BIG;
1004 }
1005
1006 if (unlikely(err))
1007 queue->rx.rsp_cons = cons + slots;
1008
1009 return err;
1010 }
1011
1012 static int xennet_set_skb_gso(struct sk_buff *skb,
1013 struct xen_netif_extra_info *gso)
1014 {
1015 if (!gso->u.gso.size) {
1016 if (net_ratelimit())
1017 pr_warn("GSO size must not be zero\n");
1018 return -EINVAL;
1019 }
1020
1021 if (gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV4 &&
1022 gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV6) {
1023 if (net_ratelimit())
1024 pr_warn("Bad GSO type %d\n", gso->u.gso.type);
1025 return -EINVAL;
1026 }
1027
1028 skb_shinfo(skb)->gso_size = gso->u.gso.size;
1029 skb_shinfo(skb)->gso_type =
1030 (gso->u.gso.type == XEN_NETIF_GSO_TYPE_TCPV4) ?
1031 SKB_GSO_TCPV4 :
1032 SKB_GSO_TCPV6;
1033
1034 /* Header must be checked, and gso_segs computed. */
1035 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
1036 skb_shinfo(skb)->gso_segs = 0;
1037
1038 return 0;
1039 }
1040
1041 static int xennet_fill_frags(struct netfront_queue *queue,
1042 struct sk_buff *skb,
1043 struct sk_buff_head *list)
1044 {
1045 RING_IDX cons = queue->rx.rsp_cons;
1046 struct sk_buff *nskb;
1047
1048 while ((nskb = __skb_dequeue(list))) {
1049 struct xen_netif_rx_response *rx =
1050 RING_GET_RESPONSE(&queue->rx, ++cons);
1051 skb_frag_t *nfrag = &skb_shinfo(nskb)->frags[0];
1052
1053 if (skb_shinfo(skb)->nr_frags == MAX_SKB_FRAGS) {
1054 unsigned int pull_to = NETFRONT_SKB_CB(skb)->pull_to;
1055
1056 BUG_ON(pull_to < skb_headlen(skb));
1057 __pskb_pull_tail(skb, pull_to - skb_headlen(skb));
1058 }
1059 if (unlikely(skb_shinfo(skb)->nr_frags >= MAX_SKB_FRAGS)) {
1060 queue->rx.rsp_cons = ++cons + skb_queue_len(list);
1061 kfree_skb(nskb);
1062 return -ENOENT;
1063 }
1064
1065 skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags,
1066 skb_frag_page(nfrag),
1067 rx->offset, rx->status, PAGE_SIZE);
1068
1069 skb_shinfo(nskb)->nr_frags = 0;
1070 kfree_skb(nskb);
1071 }
1072
1073 queue->rx.rsp_cons = cons;
1074
1075 return 0;
1076 }
1077
1078 static int checksum_setup(struct net_device *dev, struct sk_buff *skb)
1079 {
1080 bool recalculate_partial_csum = false;
1081
1082 /*
1083 * A GSO SKB must be CHECKSUM_PARTIAL. However some buggy
1084 * peers can fail to set NETRXF_csum_blank when sending a GSO
1085 * frame. In this case force the SKB to CHECKSUM_PARTIAL and
1086 * recalculate the partial checksum.
1087 */
1088 if (skb->ip_summed != CHECKSUM_PARTIAL && skb_is_gso(skb)) {
1089 struct netfront_info *np = netdev_priv(dev);
1090 atomic_inc(&np->rx_gso_checksum_fixup);
1091 skb->ip_summed = CHECKSUM_PARTIAL;
1092 recalculate_partial_csum = true;
1093 }
1094
1095 /* A non-CHECKSUM_PARTIAL SKB does not require setup. */
1096 if (skb->ip_summed != CHECKSUM_PARTIAL)
1097 return 0;
1098
1099 return skb_checksum_setup(skb, recalculate_partial_csum);
1100 }
1101
1102 static int handle_incoming_queue(struct netfront_queue *queue,
1103 struct sk_buff_head *rxq)
1104 {
1105 struct netfront_stats *rx_stats = this_cpu_ptr(queue->info->rx_stats);
1106 int packets_dropped = 0;
1107 struct sk_buff *skb;
1108
1109 while ((skb = __skb_dequeue(rxq)) != NULL) {
1110 int pull_to = NETFRONT_SKB_CB(skb)->pull_to;
1111
1112 if (pull_to > skb_headlen(skb))
1113 __pskb_pull_tail(skb, pull_to - skb_headlen(skb));
1114
1115 /* Ethernet work: Delayed to here as it peeks the header. */
1116 skb->protocol = eth_type_trans(skb, queue->info->netdev);
1117 skb_reset_network_header(skb);
1118
1119 if (checksum_setup(queue->info->netdev, skb)) {
1120 kfree_skb(skb);
1121 packets_dropped++;
1122 queue->info->netdev->stats.rx_errors++;
1123 continue;
1124 }
1125
1126 u64_stats_update_begin(&rx_stats->syncp);
1127 rx_stats->packets++;
1128 rx_stats->bytes += skb->len;
1129 u64_stats_update_end(&rx_stats->syncp);
1130
1131 /* Pass it up. */
1132 napi_gro_receive(&queue->napi, skb);
1133 }
1134
1135 return packets_dropped;
1136 }
1137
1138 static int xennet_poll(struct napi_struct *napi, int budget)
1139 {
1140 struct netfront_queue *queue = container_of(napi, struct netfront_queue, napi);
1141 struct net_device *dev = queue->info->netdev;
1142 struct sk_buff *skb;
1143 struct netfront_rx_info rinfo;
1144 struct xen_netif_rx_response *rx = &rinfo.rx;
1145 struct xen_netif_extra_info *extras = rinfo.extras;
1146 RING_IDX i, rp;
1147 int work_done;
1148 struct sk_buff_head rxq;
1149 struct sk_buff_head errq;
1150 struct sk_buff_head tmpq;
1151 int err;
1152 bool need_xdp_flush = false;
1153
1154 spin_lock(&queue->rx_lock);
1155
1156 skb_queue_head_init(&rxq);
1157 skb_queue_head_init(&errq);
1158 skb_queue_head_init(&tmpq);
1159
1160 rp = queue->rx.sring->rsp_prod;
1161 rmb(); /* Ensure we see queued responses up to 'rp'. */
1162
1163 i = queue->rx.rsp_cons;
1164 work_done = 0;
1165 while ((i != rp) && (work_done < budget)) {
1166 memcpy(rx, RING_GET_RESPONSE(&queue->rx, i), sizeof(*rx));
1167 memset(extras, 0, sizeof(rinfo.extras));
1168
1169 err = xennet_get_responses(queue, &rinfo, rp, &tmpq,
1170 &need_xdp_flush);
1171
1172 if (unlikely(err)) {
1173 err:
1174 while ((skb = __skb_dequeue(&tmpq)))
1175 __skb_queue_tail(&errq, skb);
1176 dev->stats.rx_errors++;
1177 i = queue->rx.rsp_cons;
1178 continue;
1179 }
1180
1181 skb = __skb_dequeue(&tmpq);
1182
1183 if (extras[XEN_NETIF_EXTRA_TYPE_GSO - 1].type) {
1184 struct xen_netif_extra_info *gso;
1185 gso = &extras[XEN_NETIF_EXTRA_TYPE_GSO - 1];
1186
1187 if (unlikely(xennet_set_skb_gso(skb, gso))) {
1188 __skb_queue_head(&tmpq, skb);
1189 queue->rx.rsp_cons += skb_queue_len(&tmpq);
1190 goto err;
1191 }
1192 }
1193
1194 NETFRONT_SKB_CB(skb)->pull_to = rx->status;
1195 if (NETFRONT_SKB_CB(skb)->pull_to > RX_COPY_THRESHOLD)
1196 NETFRONT_SKB_CB(skb)->pull_to = RX_COPY_THRESHOLD;
1197
1198 skb_frag_off_set(&skb_shinfo(skb)->frags[0], rx->offset);
1199 skb_frag_size_set(&skb_shinfo(skb)->frags[0], rx->status);
1200 skb->data_len = rx->status;
1201 skb->len += rx->status;
1202
1203 if (unlikely(xennet_fill_frags(queue, skb, &tmpq)))
1204 goto err;
1205
1206 if (rx->flags & XEN_NETRXF_csum_blank)
1207 skb->ip_summed = CHECKSUM_PARTIAL;
1208 else if (rx->flags & XEN_NETRXF_data_validated)
1209 skb->ip_summed = CHECKSUM_UNNECESSARY;
1210
1211 __skb_queue_tail(&rxq, skb);
1212
1213 i = ++queue->rx.rsp_cons;
1214 work_done++;
1215 }
1216 if (need_xdp_flush)
1217 xdp_do_flush();
1218
1219 __skb_queue_purge(&errq);
1220
1221 work_done -= handle_incoming_queue(queue, &rxq);
1222
1223 xennet_alloc_rx_buffers(queue);
1224
1225 if (work_done < budget) {
1226 int more_to_do = 0;
1227
1228 napi_complete_done(napi, work_done);
1229
1230 RING_FINAL_CHECK_FOR_RESPONSES(&queue->rx, more_to_do);
1231 if (more_to_do)
1232 napi_schedule(napi);
1233 }
1234
1235 spin_unlock(&queue->rx_lock);
1236
1237 return work_done;
1238 }
1239
1240 static int xennet_change_mtu(struct net_device *dev, int mtu)
1241 {
1242 int max = xennet_can_sg(dev) ? XEN_NETIF_MAX_TX_SIZE : ETH_DATA_LEN;
1243
1244 if (mtu > max)
1245 return -EINVAL;
1246 dev->mtu = mtu;
1247 return 0;
1248 }
1249
1250 static void xennet_get_stats64(struct net_device *dev,
1251 struct rtnl_link_stats64 *tot)
1252 {
1253 struct netfront_info *np = netdev_priv(dev);
1254 int cpu;
1255
1256 for_each_possible_cpu(cpu) {
1257 struct netfront_stats *rx_stats = per_cpu_ptr(np->rx_stats, cpu);
1258 struct netfront_stats *tx_stats = per_cpu_ptr(np->tx_stats, cpu);
1259 u64 rx_packets, rx_bytes, tx_packets, tx_bytes;
1260 unsigned int start;
1261
1262 do {
1263 start = u64_stats_fetch_begin_irq(&tx_stats->syncp);
1264 tx_packets = tx_stats->packets;
1265 tx_bytes = tx_stats->bytes;
1266 } while (u64_stats_fetch_retry_irq(&tx_stats->syncp, start));
1267
1268 do {
1269 start = u64_stats_fetch_begin_irq(&rx_stats->syncp);
1270 rx_packets = rx_stats->packets;
1271 rx_bytes = rx_stats->bytes;
1272 } while (u64_stats_fetch_retry_irq(&rx_stats->syncp, start));
1273
1274 tot->rx_packets += rx_packets;
1275 tot->tx_packets += tx_packets;
1276 tot->rx_bytes += rx_bytes;
1277 tot->tx_bytes += tx_bytes;
1278 }
1279
1280 tot->rx_errors = dev->stats.rx_errors;
1281 tot->tx_dropped = dev->stats.tx_dropped;
1282 }
1283
1284 static void xennet_release_tx_bufs(struct netfront_queue *queue)
1285 {
1286 struct sk_buff *skb;
1287 int i;
1288
1289 for (i = 0; i < NET_TX_RING_SIZE; i++) {
1290 /* Skip over entries which are actually freelist references */
1291 if (skb_entry_is_link(&queue->tx_skbs[i]))
1292 continue;
1293
1294 skb = queue->tx_skbs[i].skb;
1295 get_page(queue->grant_tx_page[i]);
1296 gnttab_end_foreign_access(queue->grant_tx_ref[i],
1297 GNTMAP_readonly,
1298 (unsigned long)page_address(queue->grant_tx_page[i]));
1299 queue->grant_tx_page[i] = NULL;
1300 queue->grant_tx_ref[i] = GRANT_INVALID_REF;
1301 add_id_to_freelist(&queue->tx_skb_freelist, queue->tx_skbs, i);
1302 dev_kfree_skb_irq(skb);
1303 }
1304 }
1305
1306 static void xennet_release_rx_bufs(struct netfront_queue *queue)
1307 {
1308 int id, ref;
1309
1310 spin_lock_bh(&queue->rx_lock);
1311
1312 for (id = 0; id < NET_RX_RING_SIZE; id++) {
1313 struct sk_buff *skb;
1314 struct page *page;
1315
1316 skb = queue->rx_skbs[id];
1317 if (!skb)
1318 continue;
1319
1320 ref = queue->grant_rx_ref[id];
1321 if (ref == GRANT_INVALID_REF)
1322 continue;
1323
1324 page = skb_frag_page(&skb_shinfo(skb)->frags[0]);
1325
1326 /* gnttab_end_foreign_access() needs a page ref until
1327 * foreign access is ended (which may be deferred).
1328 */
1329 get_page(page);
1330 gnttab_end_foreign_access(ref, 0,
1331 (unsigned long)page_address(page));
1332 queue->grant_rx_ref[id] = GRANT_INVALID_REF;
1333
1334 kfree_skb(skb);
1335 }
1336
1337 spin_unlock_bh(&queue->rx_lock);
1338 }
1339
1340 static netdev_features_t xennet_fix_features(struct net_device *dev,
1341 netdev_features_t features)
1342 {
1343 struct netfront_info *np = netdev_priv(dev);
1344
1345 if (features & NETIF_F_SG &&
1346 !xenbus_read_unsigned(np->xbdev->otherend, "feature-sg", 0))
1347 features &= ~NETIF_F_SG;
1348
1349 if (features & NETIF_F_IPV6_CSUM &&
1350 !xenbus_read_unsigned(np->xbdev->otherend,
1351 "feature-ipv6-csum-offload", 0))
1352 features &= ~NETIF_F_IPV6_CSUM;
1353
1354 if (features & NETIF_F_TSO &&
1355 !xenbus_read_unsigned(np->xbdev->otherend, "feature-gso-tcpv4", 0))
1356 features &= ~NETIF_F_TSO;
1357
1358 if (features & NETIF_F_TSO6 &&
1359 !xenbus_read_unsigned(np->xbdev->otherend, "feature-gso-tcpv6", 0))
1360 features &= ~NETIF_F_TSO6;
1361
1362 return features;
1363 }
1364
1365 static int xennet_set_features(struct net_device *dev,
1366 netdev_features_t features)
1367 {
1368 if (!(features & NETIF_F_SG) && dev->mtu > ETH_DATA_LEN) {
1369 netdev_info(dev, "Reducing MTU because no SG offload");
1370 dev->mtu = ETH_DATA_LEN;
1371 }
1372
1373 return 0;
1374 }
1375
1376 static irqreturn_t xennet_tx_interrupt(int irq, void *dev_id)
1377 {
1378 struct netfront_queue *queue = dev_id;
1379 unsigned long flags;
1380
1381 spin_lock_irqsave(&queue->tx_lock, flags);
1382 xennet_tx_buf_gc(queue);
1383 spin_unlock_irqrestore(&queue->tx_lock, flags);
1384
1385 return IRQ_HANDLED;
1386 }
1387
1388 static irqreturn_t xennet_rx_interrupt(int irq, void *dev_id)
1389 {
1390 struct netfront_queue *queue = dev_id;
1391 struct net_device *dev = queue->info->netdev;
1392
1393 if (likely(netif_carrier_ok(dev) &&
1394 RING_HAS_UNCONSUMED_RESPONSES(&queue->rx)))
1395 napi_schedule(&queue->napi);
1396
1397 return IRQ_HANDLED;
1398 }
1399
1400 static irqreturn_t xennet_interrupt(int irq, void *dev_id)
1401 {
1402 xennet_tx_interrupt(irq, dev_id);
1403 xennet_rx_interrupt(irq, dev_id);
1404 return IRQ_HANDLED;
1405 }
1406
1407 #ifdef CONFIG_NET_POLL_CONTROLLER
1408 static void xennet_poll_controller(struct net_device *dev)
1409 {
1410 /* Poll each queue */
1411 struct netfront_info *info = netdev_priv(dev);
1412 unsigned int num_queues = dev->real_num_tx_queues;
1413 unsigned int i;
1414 for (i = 0; i < num_queues; ++i)
1415 xennet_interrupt(0, &info->queues[i]);
1416 }
1417 #endif
1418
1419 #define NETBACK_XDP_HEADROOM_DISABLE 0
1420 #define NETBACK_XDP_HEADROOM_ENABLE 1
1421
1422 static int talk_to_netback_xdp(struct netfront_info *np, int xdp)
1423 {
1424 int err;
1425 unsigned short headroom;
1426
1427 headroom = xdp ? XDP_PACKET_HEADROOM : 0;
1428 err = xenbus_printf(XBT_NIL, np->xbdev->nodename,
1429 "xdp-headroom", "%hu",
1430 headroom);
1431 if (err)
1432 pr_warn("Error writing xdp-headroom\n");
1433
1434 return err;
1435 }
1436
1437 static int xennet_xdp_set(struct net_device *dev, struct bpf_prog *prog,
1438 struct netlink_ext_ack *extack)
1439 {
1440 unsigned long max_mtu = XEN_PAGE_SIZE - XDP_PACKET_HEADROOM;
1441 struct netfront_info *np = netdev_priv(dev);
1442 struct bpf_prog *old_prog;
1443 unsigned int i, err;
1444
1445 if (dev->mtu > max_mtu) {
1446 netdev_warn(dev, "XDP requires MTU less than %lu\n", max_mtu);
1447 return -EINVAL;
1448 }
1449
1450 if (!np->netback_has_xdp_headroom)
1451 return 0;
1452
1453 xenbus_switch_state(np->xbdev, XenbusStateReconfiguring);
1454
1455 err = talk_to_netback_xdp(np, prog ? NETBACK_XDP_HEADROOM_ENABLE :
1456 NETBACK_XDP_HEADROOM_DISABLE);
1457 if (err)
1458 return err;
1459
1460 /* avoid the race with XDP headroom adjustment */
1461 wait_event(module_wq,
1462 xenbus_read_driver_state(np->xbdev->otherend) ==
1463 XenbusStateReconfigured);
1464 np->netfront_xdp_enabled = true;
1465
1466 old_prog = rtnl_dereference(np->queues[0].xdp_prog);
1467
1468 if (prog)
1469 bpf_prog_add(prog, dev->real_num_tx_queues);
1470
1471 for (i = 0; i < dev->real_num_tx_queues; ++i)
1472 rcu_assign_pointer(np->queues[i].xdp_prog, prog);
1473
1474 if (old_prog)
1475 for (i = 0; i < dev->real_num_tx_queues; ++i)
1476 bpf_prog_put(old_prog);
1477
1478 xenbus_switch_state(np->xbdev, XenbusStateConnected);
1479
1480 return 0;
1481 }
1482
1483 static int xennet_xdp(struct net_device *dev, struct netdev_bpf *xdp)
1484 {
1485 switch (xdp->command) {
1486 case XDP_SETUP_PROG:
1487 return xennet_xdp_set(dev, xdp->prog, xdp->extack);
1488 default:
1489 return -EINVAL;
1490 }
1491 }
1492
1493 static const struct net_device_ops xennet_netdev_ops = {
1494 .ndo_open = xennet_open,
1495 .ndo_stop = xennet_close,
1496 .ndo_start_xmit = xennet_start_xmit,
1497 .ndo_change_mtu = xennet_change_mtu,
1498 .ndo_get_stats64 = xennet_get_stats64,
1499 .ndo_set_mac_address = eth_mac_addr,
1500 .ndo_validate_addr = eth_validate_addr,
1501 .ndo_fix_features = xennet_fix_features,
1502 .ndo_set_features = xennet_set_features,
1503 .ndo_select_queue = xennet_select_queue,
1504 .ndo_bpf = xennet_xdp,
1505 .ndo_xdp_xmit = xennet_xdp_xmit,
1506 #ifdef CONFIG_NET_POLL_CONTROLLER
1507 .ndo_poll_controller = xennet_poll_controller,
1508 #endif
1509 };
1510
1511 static void xennet_free_netdev(struct net_device *netdev)
1512 {
1513 struct netfront_info *np = netdev_priv(netdev);
1514
1515 free_percpu(np->rx_stats);
1516 free_percpu(np->tx_stats);
1517 free_netdev(netdev);
1518 }
1519
1520 static struct net_device *xennet_create_dev(struct xenbus_device *dev)
1521 {
1522 int err;
1523 struct net_device *netdev;
1524 struct netfront_info *np;
1525
1526 netdev = alloc_etherdev_mq(sizeof(struct netfront_info), xennet_max_queues);
1527 if (!netdev)
1528 return ERR_PTR(-ENOMEM);
1529
1530 np = netdev_priv(netdev);
1531 np->xbdev = dev;
1532
1533 np->queues = NULL;
1534
1535 err = -ENOMEM;
1536 np->rx_stats = netdev_alloc_pcpu_stats(struct netfront_stats);
1537 if (np->rx_stats == NULL)
1538 goto exit;
1539 np->tx_stats = netdev_alloc_pcpu_stats(struct netfront_stats);
1540 if (np->tx_stats == NULL)
1541 goto exit;
1542
1543 netdev->netdev_ops = &xennet_netdev_ops;
1544
1545 netdev->features = NETIF_F_IP_CSUM | NETIF_F_RXCSUM |
1546 NETIF_F_GSO_ROBUST;
1547 netdev->hw_features = NETIF_F_SG |
1548 NETIF_F_IPV6_CSUM |
1549 NETIF_F_TSO | NETIF_F_TSO6;
1550
1551 /*
1552 * Assume that all hw features are available for now. This set
1553 * will be adjusted by the call to netdev_update_features() in
1554 * xennet_connect() which is the earliest point where we can
1555 * negotiate with the backend regarding supported features.
1556 */
1557 netdev->features |= netdev->hw_features;
1558
1559 netdev->ethtool_ops = &xennet_ethtool_ops;
1560 netdev->min_mtu = ETH_MIN_MTU;
1561 netdev->max_mtu = XEN_NETIF_MAX_TX_SIZE;
1562 SET_NETDEV_DEV(netdev, &dev->dev);
1563
1564 np->netdev = netdev;
1565 np->netfront_xdp_enabled = false;
1566
1567 netif_carrier_off(netdev);
1568
1569 do {
1570 xenbus_switch_state(dev, XenbusStateInitialising);
1571 err = wait_event_timeout(module_wq,
1572 xenbus_read_driver_state(dev->otherend) !=
1573 XenbusStateClosed &&
1574 xenbus_read_driver_state(dev->otherend) !=
1575 XenbusStateUnknown, XENNET_TIMEOUT);
1576 } while (!err);
1577
1578 return netdev;
1579
1580 exit:
1581 xennet_free_netdev(netdev);
1582 return ERR_PTR(err);
1583 }
1584
1585 /**
1586 * Entry point to this code when a new device is created. Allocate the basic
1587 * structures and the ring buffers for communication with the backend, and
1588 * inform the backend of the appropriate details for those.
1589 */
1590 static int netfront_probe(struct xenbus_device *dev,
1591 const struct xenbus_device_id *id)
1592 {
1593 int err;
1594 struct net_device *netdev;
1595 struct netfront_info *info;
1596
1597 netdev = xennet_create_dev(dev);
1598 if (IS_ERR(netdev)) {
1599 err = PTR_ERR(netdev);
1600 xenbus_dev_fatal(dev, err, "creating netdev");
1601 return err;
1602 }
1603
1604 info = netdev_priv(netdev);
1605 dev_set_drvdata(&dev->dev, info);
1606 #ifdef CONFIG_SYSFS
1607 info->netdev->sysfs_groups[0] = &xennet_dev_group;
1608 #endif
1609
1610 return 0;
1611 }
1612
1613 static void xennet_end_access(int ref, void *page)
1614 {
1615 /* This frees the page as a side-effect */
1616 if (ref != GRANT_INVALID_REF)
1617 gnttab_end_foreign_access(ref, 0, (unsigned long)page);
1618 }
1619
1620 static void xennet_disconnect_backend(struct netfront_info *info)
1621 {
1622 unsigned int i = 0;
1623 unsigned int num_queues = info->netdev->real_num_tx_queues;
1624
1625 netif_carrier_off(info->netdev);
1626
1627 for (i = 0; i < num_queues && info->queues; ++i) {
1628 struct netfront_queue *queue = &info->queues[i];
1629
1630 del_timer_sync(&queue->rx_refill_timer);
1631
1632 if (queue->tx_irq && (queue->tx_irq == queue->rx_irq))
1633 unbind_from_irqhandler(queue->tx_irq, queue);
1634 if (queue->tx_irq && (queue->tx_irq != queue->rx_irq)) {
1635 unbind_from_irqhandler(queue->tx_irq, queue);
1636 unbind_from_irqhandler(queue->rx_irq, queue);
1637 }
1638 queue->tx_evtchn = queue->rx_evtchn = 0;
1639 queue->tx_irq = queue->rx_irq = 0;
1640
1641 if (netif_running(info->netdev))
1642 napi_synchronize(&queue->napi);
1643
1644 xennet_release_tx_bufs(queue);
1645 xennet_release_rx_bufs(queue);
1646 gnttab_free_grant_references(queue->gref_tx_head);
1647 gnttab_free_grant_references(queue->gref_rx_head);
1648
1649 /* End access and free the pages */
1650 xennet_end_access(queue->tx_ring_ref, queue->tx.sring);
1651 xennet_end_access(queue->rx_ring_ref, queue->rx.sring);
1652
1653 queue->tx_ring_ref = GRANT_INVALID_REF;
1654 queue->rx_ring_ref = GRANT_INVALID_REF;
1655 queue->tx.sring = NULL;
1656 queue->rx.sring = NULL;
1657
1658 page_pool_destroy(queue->page_pool);
1659 }
1660 }
1661
1662 /**
1663 * We are reconnecting to the backend, due to a suspend/resume, or a backend
1664 * driver restart. We tear down our netif structure and recreate it, but
1665 * leave the device-layer structures intact so that this is transparent to the
1666 * rest of the kernel.
1667 */
1668 static int netfront_resume(struct xenbus_device *dev)
1669 {
1670 struct netfront_info *info = dev_get_drvdata(&dev->dev);
1671
1672 dev_dbg(&dev->dev, "%s\n", dev->nodename);
1673
1674 xennet_disconnect_backend(info);
1675 return 0;
1676 }
1677
1678 static int xen_net_read_mac(struct xenbus_device *dev, u8 mac[])
1679 {
1680 char *s, *e, *macstr;
1681 int i;
1682
1683 macstr = s = xenbus_read(XBT_NIL, dev->nodename, "mac", NULL);
1684 if (IS_ERR(macstr))
1685 return PTR_ERR(macstr);
1686
1687 for (i = 0; i < ETH_ALEN; i++) {
1688 mac[i] = simple_strtoul(s, &e, 16);
1689 if ((s == e) || (*e != ((i == ETH_ALEN-1) ? '\0' : ':'))) {
1690 kfree(macstr);
1691 return -ENOENT;
1692 }
1693 s = e+1;
1694 }
1695
1696 kfree(macstr);
1697 return 0;
1698 }
1699
1700 static int setup_netfront_single(struct netfront_queue *queue)
1701 {
1702 int err;
1703
1704 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->tx_evtchn);
1705 if (err < 0)
1706 goto fail;
1707
1708 err = bind_evtchn_to_irqhandler(queue->tx_evtchn,
1709 xennet_interrupt,
1710 0, queue->info->netdev->name, queue);
1711 if (err < 0)
1712 goto bind_fail;
1713 queue->rx_evtchn = queue->tx_evtchn;
1714 queue->rx_irq = queue->tx_irq = err;
1715
1716 return 0;
1717
1718 bind_fail:
1719 xenbus_free_evtchn(queue->info->xbdev, queue->tx_evtchn);
1720 queue->tx_evtchn = 0;
1721 fail:
1722 return err;
1723 }
1724
1725 static int setup_netfront_split(struct netfront_queue *queue)
1726 {
1727 int err;
1728
1729 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->tx_evtchn);
1730 if (err < 0)
1731 goto fail;
1732 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->rx_evtchn);
1733 if (err < 0)
1734 goto alloc_rx_evtchn_fail;
1735
1736 snprintf(queue->tx_irq_name, sizeof(queue->tx_irq_name),
1737 "%s-tx", queue->name);
1738 err = bind_evtchn_to_irqhandler(queue->tx_evtchn,
1739 xennet_tx_interrupt,
1740 0, queue->tx_irq_name, queue);
1741 if (err < 0)
1742 goto bind_tx_fail;
1743 queue->tx_irq = err;
1744
1745 snprintf(queue->rx_irq_name, sizeof(queue->rx_irq_name),
1746 "%s-rx", queue->name);
1747 err = bind_evtchn_to_irqhandler(queue->rx_evtchn,
1748 xennet_rx_interrupt,
1749 0, queue->rx_irq_name, queue);
1750 if (err < 0)
1751 goto bind_rx_fail;
1752 queue->rx_irq = err;
1753
1754 return 0;
1755
1756 bind_rx_fail:
1757 unbind_from_irqhandler(queue->tx_irq, queue);
1758 queue->tx_irq = 0;
1759 bind_tx_fail:
1760 xenbus_free_evtchn(queue->info->xbdev, queue->rx_evtchn);
1761 queue->rx_evtchn = 0;
1762 alloc_rx_evtchn_fail:
1763 xenbus_free_evtchn(queue->info->xbdev, queue->tx_evtchn);
1764 queue->tx_evtchn = 0;
1765 fail:
1766 return err;
1767 }
1768
1769 static int setup_netfront(struct xenbus_device *dev,
1770 struct netfront_queue *queue, unsigned int feature_split_evtchn)
1771 {
1772 struct xen_netif_tx_sring *txs;
1773 struct xen_netif_rx_sring *rxs;
1774 grant_ref_t gref;
1775 int err;
1776
1777 queue->tx_ring_ref = GRANT_INVALID_REF;
1778 queue->rx_ring_ref = GRANT_INVALID_REF;
1779 queue->rx.sring = NULL;
1780 queue->tx.sring = NULL;
1781
1782 txs = (struct xen_netif_tx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH);
1783 if (!txs) {
1784 err = -ENOMEM;
1785 xenbus_dev_fatal(dev, err, "allocating tx ring page");
1786 goto fail;
1787 }
1788 SHARED_RING_INIT(txs);
1789 FRONT_RING_INIT(&queue->tx, txs, XEN_PAGE_SIZE);
1790
1791 err = xenbus_grant_ring(dev, txs, 1, &gref);
1792 if (err < 0)
1793 goto grant_tx_ring_fail;
1794 queue->tx_ring_ref = gref;
1795
1796 rxs = (struct xen_netif_rx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH);
1797 if (!rxs) {
1798 err = -ENOMEM;
1799 xenbus_dev_fatal(dev, err, "allocating rx ring page");
1800 goto alloc_rx_ring_fail;
1801 }
1802 SHARED_RING_INIT(rxs);
1803 FRONT_RING_INIT(&queue->rx, rxs, XEN_PAGE_SIZE);
1804
1805 err = xenbus_grant_ring(dev, rxs, 1, &gref);
1806 if (err < 0)
1807 goto grant_rx_ring_fail;
1808 queue->rx_ring_ref = gref;
1809
1810 if (feature_split_evtchn)
1811 err = setup_netfront_split(queue);
1812 /* setup single event channel if
1813 * a) feature-split-event-channels == 0
1814 * b) feature-split-event-channels == 1 but failed to setup
1815 */
1816 if (!feature_split_evtchn || (feature_split_evtchn && err))
1817 err = setup_netfront_single(queue);
1818
1819 if (err)
1820 goto alloc_evtchn_fail;
1821
1822 return 0;
1823
1824 /* If we fail to setup netfront, it is safe to just revoke access to
1825 * granted pages because backend is not accessing it at this point.
1826 */
1827 alloc_evtchn_fail:
1828 gnttab_end_foreign_access_ref(queue->rx_ring_ref, 0);
1829 grant_rx_ring_fail:
1830 free_page((unsigned long)rxs);
1831 alloc_rx_ring_fail:
1832 gnttab_end_foreign_access_ref(queue->tx_ring_ref, 0);
1833 grant_tx_ring_fail:
1834 free_page((unsigned long)txs);
1835 fail:
1836 return err;
1837 }
1838
1839 /* Queue-specific initialisation
1840 * This used to be done in xennet_create_dev() but must now
1841 * be run per-queue.
1842 */
1843 static int xennet_init_queue(struct netfront_queue *queue)
1844 {
1845 unsigned short i;
1846 int err = 0;
1847 char *devid;
1848
1849 spin_lock_init(&queue->tx_lock);
1850 spin_lock_init(&queue->rx_lock);
1851
1852 timer_setup(&queue->rx_refill_timer, rx_refill_timeout, 0);
1853
1854 devid = strrchr(queue->info->xbdev->nodename, '/') + 1;
1855 snprintf(queue->name, sizeof(queue->name), "vif%s-q%u",
1856 devid, queue->id);
1857
1858 /* Initialise tx_skbs as a free chain containing every entry. */
1859 queue->tx_skb_freelist = 0;
1860 for (i = 0; i < NET_TX_RING_SIZE; i++) {
1861 skb_entry_set_link(&queue->tx_skbs[i], i+1);
1862 queue->grant_tx_ref[i] = GRANT_INVALID_REF;
1863 queue->grant_tx_page[i] = NULL;
1864 }
1865
1866 /* Clear out rx_skbs */
1867 for (i = 0; i < NET_RX_RING_SIZE; i++) {
1868 queue->rx_skbs[i] = NULL;
1869 queue->grant_rx_ref[i] = GRANT_INVALID_REF;
1870 }
1871
1872 /* A grant for every tx ring slot */
1873 if (gnttab_alloc_grant_references(NET_TX_RING_SIZE,
1874 &queue->gref_tx_head) < 0) {
1875 pr_alert("can't alloc tx grant refs\n");
1876 err = -ENOMEM;
1877 goto exit;
1878 }
1879
1880 /* A grant for every rx ring slot */
1881 if (gnttab_alloc_grant_references(NET_RX_RING_SIZE,
1882 &queue->gref_rx_head) < 0) {
1883 pr_alert("can't alloc rx grant refs\n");
1884 err = -ENOMEM;
1885 goto exit_free_tx;
1886 }
1887
1888 return 0;
1889
1890 exit_free_tx:
1891 gnttab_free_grant_references(queue->gref_tx_head);
1892 exit:
1893 return err;
1894 }
1895
1896 static int write_queue_xenstore_keys(struct netfront_queue *queue,
1897 struct xenbus_transaction *xbt, int write_hierarchical)
1898 {
1899 /* Write the queue-specific keys into XenStore in the traditional
1900 * way for a single queue, or in a queue subkeys for multiple
1901 * queues.
1902 */
1903 struct xenbus_device *dev = queue->info->xbdev;
1904 int err;
1905 const char *message;
1906 char *path;
1907 size_t pathsize;
1908
1909 /* Choose the correct place to write the keys */
1910 if (write_hierarchical) {
1911 pathsize = strlen(dev->nodename) + 10;
1912 path = kzalloc(pathsize, GFP_KERNEL);
1913 if (!path) {
1914 err = -ENOMEM;
1915 message = "out of memory while writing ring references";
1916 goto error;
1917 }
1918 snprintf(path, pathsize, "%s/queue-%u",
1919 dev->nodename, queue->id);
1920 } else {
1921 path = (char *)dev->nodename;
1922 }
1923
1924 /* Write ring references */
1925 err = xenbus_printf(*xbt, path, "tx-ring-ref", "%u",
1926 queue->tx_ring_ref);
1927 if (err) {
1928 message = "writing tx-ring-ref";
1929 goto error;
1930 }
1931
1932 err = xenbus_printf(*xbt, path, "rx-ring-ref", "%u",
1933 queue->rx_ring_ref);
1934 if (err) {
1935 message = "writing rx-ring-ref";
1936 goto error;
1937 }
1938
1939 /* Write event channels; taking into account both shared
1940 * and split event channel scenarios.
1941 */
1942 if (queue->tx_evtchn == queue->rx_evtchn) {
1943 /* Shared event channel */
1944 err = xenbus_printf(*xbt, path,
1945 "event-channel", "%u", queue->tx_evtchn);
1946 if (err) {
1947 message = "writing event-channel";
1948 goto error;
1949 }
1950 } else {
1951 /* Split event channels */
1952 err = xenbus_printf(*xbt, path,
1953 "event-channel-tx", "%u", queue->tx_evtchn);
1954 if (err) {
1955 message = "writing event-channel-tx";
1956 goto error;
1957 }
1958
1959 err = xenbus_printf(*xbt, path,
1960 "event-channel-rx", "%u", queue->rx_evtchn);
1961 if (err) {
1962 message = "writing event-channel-rx";
1963 goto error;
1964 }
1965 }
1966
1967 if (write_hierarchical)
1968 kfree(path);
1969 return 0;
1970
1971 error:
1972 if (write_hierarchical)
1973 kfree(path);
1974 xenbus_dev_fatal(dev, err, "%s", message);
1975 return err;
1976 }
1977
1978 static void xennet_destroy_queues(struct netfront_info *info)
1979 {
1980 unsigned int i;
1981
1982 for (i = 0; i < info->netdev->real_num_tx_queues; i++) {
1983 struct netfront_queue *queue = &info->queues[i];
1984
1985 if (netif_running(info->netdev))
1986 napi_disable(&queue->napi);
1987 netif_napi_del(&queue->napi);
1988 }
1989
1990 kfree(info->queues);
1991 info->queues = NULL;
1992 }
1993
1994
1995
1996 static int xennet_create_page_pool(struct netfront_queue *queue)
1997 {
1998 int err;
1999 struct page_pool_params pp_params = {
2000 .order = 0,
2001 .flags = 0,
2002 .pool_size = NET_RX_RING_SIZE,
2003 .nid = NUMA_NO_NODE,
2004 .dev = &queue->info->netdev->dev,
2005 .offset = XDP_PACKET_HEADROOM,
2006 .max_len = XEN_PAGE_SIZE - XDP_PACKET_HEADROOM,
2007 };
2008
2009 queue->page_pool = page_pool_create(&pp_params);
2010 if (IS_ERR(queue->page_pool)) {
2011 err = PTR_ERR(queue->page_pool);
2012 queue->page_pool = NULL;
2013 return err;
2014 }
2015
2016 err = xdp_rxq_info_reg(&queue->xdp_rxq, queue->info->netdev,
2017 queue->id, 0);
2018 if (err) {
2019 netdev_err(queue->info->netdev, "xdp_rxq_info_reg failed\n");
2020 goto err_free_pp;
2021 }
2022
2023 err = xdp_rxq_info_reg_mem_model(&queue->xdp_rxq,
2024 MEM_TYPE_PAGE_POOL, queue->page_pool);
2025 if (err) {
2026 netdev_err(queue->info->netdev, "xdp_rxq_info_reg_mem_model failed\n");
2027 goto err_unregister_rxq;
2028 }
2029 return 0;
2030
2031 err_unregister_rxq:
2032 xdp_rxq_info_unreg(&queue->xdp_rxq);
2033 err_free_pp:
2034 page_pool_destroy(queue->page_pool);
2035 queue->page_pool = NULL;
2036 return err;
2037 }
2038
2039 static int xennet_create_queues(struct netfront_info *info,
2040 unsigned int *num_queues)
2041 {
2042 unsigned int i;
2043 int ret;
2044
2045 info->queues = kcalloc(*num_queues, sizeof(struct netfront_queue),
2046 GFP_KERNEL);
2047 if (!info->queues)
2048 return -ENOMEM;
2049
2050 for (i = 0; i < *num_queues; i++) {
2051 struct netfront_queue *queue = &info->queues[i];
2052
2053 queue->id = i;
2054 queue->info = info;
2055
2056 ret = xennet_init_queue(queue);
2057 if (ret < 0) {
2058 dev_warn(&info->xbdev->dev,
2059 "only created %d queues\n", i);
2060 *num_queues = i;
2061 break;
2062 }
2063
2064 /* use page pool recycling instead of buddy allocator */
2065 ret = xennet_create_page_pool(queue);
2066 if (ret < 0) {
2067 dev_err(&info->xbdev->dev, "can't allocate page pool\n");
2068 *num_queues = i;
2069 return ret;
2070 }
2071
2072 netif_napi_add(queue->info->netdev, &queue->napi,
2073 xennet_poll, 64);
2074 if (netif_running(info->netdev))
2075 napi_enable(&queue->napi);
2076 }
2077
2078 netif_set_real_num_tx_queues(info->netdev, *num_queues);
2079
2080 if (*num_queues == 0) {
2081 dev_err(&info->xbdev->dev, "no queues\n");
2082 return -EINVAL;
2083 }
2084 return 0;
2085 }
2086
2087 /* Common code used when first setting up, and when resuming. */
2088 static int talk_to_netback(struct xenbus_device *dev,
2089 struct netfront_info *info)
2090 {
2091 const char *message;
2092 struct xenbus_transaction xbt;
2093 int err;
2094 unsigned int feature_split_evtchn;
2095 unsigned int i = 0;
2096 unsigned int max_queues = 0;
2097 struct netfront_queue *queue = NULL;
2098 unsigned int num_queues = 1;
2099
2100 info->netdev->irq = 0;
2101
2102 /* Check if backend supports multiple queues */
2103 max_queues = xenbus_read_unsigned(info->xbdev->otherend,
2104 "multi-queue-max-queues", 1);
2105 num_queues = min(max_queues, xennet_max_queues);
2106
2107 /* Check feature-split-event-channels */
2108 feature_split_evtchn = xenbus_read_unsigned(info->xbdev->otherend,
2109 "feature-split-event-channels", 0);
2110
2111 /* Read mac addr. */
2112 err = xen_net_read_mac(dev, info->netdev->dev_addr);
2113 if (err) {
2114 xenbus_dev_fatal(dev, err, "parsing %s/mac", dev->nodename);
2115 goto out_unlocked;
2116 }
2117
2118 info->netback_has_xdp_headroom = xenbus_read_unsigned(info->xbdev->otherend,
2119 "feature-xdp-headroom", 0);
2120 if (info->netback_has_xdp_headroom) {
2121 /* set the current xen-netfront xdp state */
2122 err = talk_to_netback_xdp(info, info->netfront_xdp_enabled ?
2123 NETBACK_XDP_HEADROOM_ENABLE :
2124 NETBACK_XDP_HEADROOM_DISABLE);
2125 if (err)
2126 goto out_unlocked;
2127 }
2128
2129 rtnl_lock();
2130 if (info->queues)
2131 xennet_destroy_queues(info);
2132
2133 err = xennet_create_queues(info, &num_queues);
2134 if (err < 0) {
2135 xenbus_dev_fatal(dev, err, "creating queues");
2136 kfree(info->queues);
2137 info->queues = NULL;
2138 goto out;
2139 }
2140 rtnl_unlock();
2141
2142 /* Create shared ring, alloc event channel -- for each queue */
2143 for (i = 0; i < num_queues; ++i) {
2144 queue = &info->queues[i];
2145 err = setup_netfront(dev, queue, feature_split_evtchn);
2146 if (err)
2147 goto destroy_ring;
2148 }
2149
2150 again:
2151 err = xenbus_transaction_start(&xbt);
2152 if (err) {
2153 xenbus_dev_fatal(dev, err, "starting transaction");
2154 goto destroy_ring;
2155 }
2156
2157 if (xenbus_exists(XBT_NIL,
2158 info->xbdev->otherend, "multi-queue-max-queues")) {
2159 /* Write the number of queues */
2160 err = xenbus_printf(xbt, dev->nodename,
2161 "multi-queue-num-queues", "%u", num_queues);
2162 if (err) {
2163 message = "writing multi-queue-num-queues";
2164 goto abort_transaction_no_dev_fatal;
2165 }
2166 }
2167
2168 if (num_queues == 1) {
2169 err = write_queue_xenstore_keys(&info->queues[0], &xbt, 0); /* flat */
2170 if (err)
2171 goto abort_transaction_no_dev_fatal;
2172 } else {
2173 /* Write the keys for each queue */
2174 for (i = 0; i < num_queues; ++i) {
2175 queue = &info->queues[i];
2176 err = write_queue_xenstore_keys(queue, &xbt, 1); /* hierarchical */
2177 if (err)
2178 goto abort_transaction_no_dev_fatal;
2179 }
2180 }
2181
2182 /* The remaining keys are not queue-specific */
2183 err = xenbus_printf(xbt, dev->nodename, "request-rx-copy", "%u",
2184 1);
2185 if (err) {
2186 message = "writing request-rx-copy";
2187 goto abort_transaction;
2188 }
2189
2190 err = xenbus_printf(xbt, dev->nodename, "feature-rx-notify", "%d", 1);
2191 if (err) {
2192 message = "writing feature-rx-notify";
2193 goto abort_transaction;
2194 }
2195
2196 err = xenbus_printf(xbt, dev->nodename, "feature-sg", "%d", 1);
2197 if (err) {
2198 message = "writing feature-sg";
2199 goto abort_transaction;
2200 }
2201
2202 err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv4", "%d", 1);
2203 if (err) {
2204 message = "writing feature-gso-tcpv4";
2205 goto abort_transaction;
2206 }
2207
2208 err = xenbus_write(xbt, dev->nodename, "feature-gso-tcpv6", "1");
2209 if (err) {
2210 message = "writing feature-gso-tcpv6";
2211 goto abort_transaction;
2212 }
2213
2214 err = xenbus_write(xbt, dev->nodename, "feature-ipv6-csum-offload",
2215 "1");
2216 if (err) {
2217 message = "writing feature-ipv6-csum-offload";
2218 goto abort_transaction;
2219 }
2220
2221 err = xenbus_transaction_end(xbt, 0);
2222 if (err) {
2223 if (err == -EAGAIN)
2224 goto again;
2225 xenbus_dev_fatal(dev, err, "completing transaction");
2226 goto destroy_ring;
2227 }
2228
2229 return 0;
2230
2231 abort_transaction:
2232 xenbus_dev_fatal(dev, err, "%s", message);
2233 abort_transaction_no_dev_fatal:
2234 xenbus_transaction_end(xbt, 1);
2235 destroy_ring:
2236 xennet_disconnect_backend(info);
2237 rtnl_lock();
2238 xennet_destroy_queues(info);
2239 out:
2240 rtnl_unlock();
2241 out_unlocked:
2242 device_unregister(&dev->dev);
2243 return err;
2244 }
2245
2246 static int xennet_connect(struct net_device *dev)
2247 {
2248 struct netfront_info *np = netdev_priv(dev);
2249 unsigned int num_queues = 0;
2250 int err;
2251 unsigned int j = 0;
2252 struct netfront_queue *queue = NULL;
2253
2254 if (!xenbus_read_unsigned(np->xbdev->otherend, "feature-rx-copy", 0)) {
2255 dev_info(&dev->dev,
2256 "backend does not support copying receive path\n");
2257 return -ENODEV;
2258 }
2259
2260 err = talk_to_netback(np->xbdev, np);
2261 if (err)
2262 return err;
2263 if (np->netback_has_xdp_headroom)
2264 pr_info("backend supports XDP headroom\n");
2265
2266 /* talk_to_netback() sets the correct number of queues */
2267 num_queues = dev->real_num_tx_queues;
2268
2269 if (dev->reg_state == NETREG_UNINITIALIZED) {
2270 err = register_netdev(dev);
2271 if (err) {
2272 pr_warn("%s: register_netdev err=%d\n", __func__, err);
2273 device_unregister(&np->xbdev->dev);
2274 return err;
2275 }
2276 }
2277
2278 rtnl_lock();
2279 netdev_update_features(dev);
2280 rtnl_unlock();
2281
2282 /*
2283 * All public and private state should now be sane. Get
2284 * ready to start sending and receiving packets and give the driver
2285 * domain a kick because we've probably just requeued some
2286 * packets.
2287 */
2288 netif_carrier_on(np->netdev);
2289 for (j = 0; j < num_queues; ++j) {
2290 queue = &np->queues[j];
2291
2292 notify_remote_via_irq(queue->tx_irq);
2293 if (queue->tx_irq != queue->rx_irq)
2294 notify_remote_via_irq(queue->rx_irq);
2295
2296 spin_lock_irq(&queue->tx_lock);
2297 xennet_tx_buf_gc(queue);
2298 spin_unlock_irq(&queue->tx_lock);
2299
2300 spin_lock_bh(&queue->rx_lock);
2301 xennet_alloc_rx_buffers(queue);
2302 spin_unlock_bh(&queue->rx_lock);
2303 }
2304
2305 return 0;
2306 }
2307
2308 /**
2309 * Callback received when the backend's state changes.
2310 */
2311 static void netback_changed(struct xenbus_device *dev,
2312 enum xenbus_state backend_state)
2313 {
2314 struct netfront_info *np = dev_get_drvdata(&dev->dev);
2315 struct net_device *netdev = np->netdev;
2316
2317 dev_dbg(&dev->dev, "%s\n", xenbus_strstate(backend_state));
2318
2319 wake_up_all(&module_wq);
2320
2321 switch (backend_state) {
2322 case XenbusStateInitialising:
2323 case XenbusStateInitialised:
2324 case XenbusStateReconfiguring:
2325 case XenbusStateReconfigured:
2326 case XenbusStateUnknown:
2327 break;
2328
2329 case XenbusStateInitWait:
2330 if (dev->state != XenbusStateInitialising)
2331 break;
2332 if (xennet_connect(netdev) != 0)
2333 break;
2334 xenbus_switch_state(dev, XenbusStateConnected);
2335 break;
2336
2337 case XenbusStateConnected:
2338 netdev_notify_peers(netdev);
2339 break;
2340
2341 case XenbusStateClosed:
2342 if (dev->state == XenbusStateClosed)
2343 break;
2344 fallthrough; /* Missed the backend's CLOSING state */
2345 case XenbusStateClosing:
2346 xenbus_frontend_closed(dev);
2347 break;
2348 }
2349 }
2350
2351 static const struct xennet_stat {
2352 char name[ETH_GSTRING_LEN];
2353 u16 offset;
2354 } xennet_stats[] = {
2355 {
2356 "rx_gso_checksum_fixup",
2357 offsetof(struct netfront_info, rx_gso_checksum_fixup)
2358 },
2359 };
2360
2361 static int xennet_get_sset_count(struct net_device *dev, int string_set)
2362 {
2363 switch (string_set) {
2364 case ETH_SS_STATS:
2365 return ARRAY_SIZE(xennet_stats);
2366 default:
2367 return -EINVAL;
2368 }
2369 }
2370
2371 static void xennet_get_ethtool_stats(struct net_device *dev,
2372 struct ethtool_stats *stats, u64 * data)
2373 {
2374 void *np = netdev_priv(dev);
2375 int i;
2376
2377 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++)
2378 data[i] = atomic_read((atomic_t *)(np + xennet_stats[i].offset));
2379 }
2380
2381 static void xennet_get_strings(struct net_device *dev, u32 stringset, u8 * data)
2382 {
2383 int i;
2384
2385 switch (stringset) {
2386 case ETH_SS_STATS:
2387 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++)
2388 memcpy(data + i * ETH_GSTRING_LEN,
2389 xennet_stats[i].name, ETH_GSTRING_LEN);
2390 break;
2391 }
2392 }
2393
2394 static const struct ethtool_ops xennet_ethtool_ops =
2395 {
2396 .get_link = ethtool_op_get_link,
2397
2398 .get_sset_count = xennet_get_sset_count,
2399 .get_ethtool_stats = xennet_get_ethtool_stats,
2400 .get_strings = xennet_get_strings,
2401 .get_ts_info = ethtool_op_get_ts_info,
2402 };
2403
2404 #ifdef CONFIG_SYSFS
2405 static ssize_t show_rxbuf(struct device *dev,
2406 struct device_attribute *attr, char *buf)
2407 {
2408 return sprintf(buf, "%lu\n", NET_RX_RING_SIZE);
2409 }
2410
2411 static ssize_t store_rxbuf(struct device *dev,
2412 struct device_attribute *attr,
2413 const char *buf, size_t len)
2414 {
2415 char *endp;
2416
2417 if (!capable(CAP_NET_ADMIN))
2418 return -EPERM;
2419
2420 simple_strtoul(buf, &endp, 0);
2421 if (endp == buf)
2422 return -EBADMSG;
2423
2424 /* rxbuf_min and rxbuf_max are no longer configurable. */
2425
2426 return len;
2427 }
2428
2429 static DEVICE_ATTR(rxbuf_min, 0644, show_rxbuf, store_rxbuf);
2430 static DEVICE_ATTR(rxbuf_max, 0644, show_rxbuf, store_rxbuf);
2431 static DEVICE_ATTR(rxbuf_cur, 0444, show_rxbuf, NULL);
2432
2433 static struct attribute *xennet_dev_attrs[] = {
2434 &dev_attr_rxbuf_min.attr,
2435 &dev_attr_rxbuf_max.attr,
2436 &dev_attr_rxbuf_cur.attr,
2437 NULL
2438 };
2439
2440 static const struct attribute_group xennet_dev_group = {
2441 .attrs = xennet_dev_attrs
2442 };
2443 #endif /* CONFIG_SYSFS */
2444
2445 static void xennet_bus_close(struct xenbus_device *dev)
2446 {
2447 int ret;
2448
2449 if (xenbus_read_driver_state(dev->otherend) == XenbusStateClosed)
2450 return;
2451 do {
2452 xenbus_switch_state(dev, XenbusStateClosing);
2453 ret = wait_event_timeout(module_wq,
2454 xenbus_read_driver_state(dev->otherend) ==
2455 XenbusStateClosing ||
2456 xenbus_read_driver_state(dev->otherend) ==
2457 XenbusStateClosed ||
2458 xenbus_read_driver_state(dev->otherend) ==
2459 XenbusStateUnknown,
2460 XENNET_TIMEOUT);
2461 } while (!ret);
2462
2463 if (xenbus_read_driver_state(dev->otherend) == XenbusStateClosed)
2464 return;
2465
2466 do {
2467 xenbus_switch_state(dev, XenbusStateClosed);
2468 ret = wait_event_timeout(module_wq,
2469 xenbus_read_driver_state(dev->otherend) ==
2470 XenbusStateClosed ||
2471 xenbus_read_driver_state(dev->otherend) ==
2472 XenbusStateUnknown,
2473 XENNET_TIMEOUT);
2474 } while (!ret);
2475 }
2476
2477 static int xennet_remove(struct xenbus_device *dev)
2478 {
2479 struct netfront_info *info = dev_get_drvdata(&dev->dev);
2480
2481 xennet_bus_close(dev);
2482 xennet_disconnect_backend(info);
2483
2484 if (info->netdev->reg_state == NETREG_REGISTERED)
2485 unregister_netdev(info->netdev);
2486
2487 if (info->queues) {
2488 rtnl_lock();
2489 xennet_destroy_queues(info);
2490 rtnl_unlock();
2491 }
2492 xennet_free_netdev(info->netdev);
2493
2494 return 0;
2495 }
2496
2497 static const struct xenbus_device_id netfront_ids[] = {
2498 { "vif" },
2499 { "" }
2500 };
2501
2502 static struct xenbus_driver netfront_driver = {
2503 .ids = netfront_ids,
2504 .probe = netfront_probe,
2505 .remove = xennet_remove,
2506 .resume = netfront_resume,
2507 .otherend_changed = netback_changed,
2508 };
2509
2510 static int __init netif_init(void)
2511 {
2512 if (!xen_domain())
2513 return -ENODEV;
2514
2515 if (!xen_has_pv_nic_devices())
2516 return -ENODEV;
2517
2518 pr_info("Initialising Xen virtual ethernet driver\n");
2519
2520 /* Allow as many queues as there are CPUs inut max. 8 if user has not
2521 * specified a value.
2522 */
2523 if (xennet_max_queues == 0)
2524 xennet_max_queues = min_t(unsigned int, MAX_QUEUES_DEFAULT,
2525 num_online_cpus());
2526
2527 return xenbus_register_frontend(&netfront_driver);
2528 }
2529 module_init(netif_init);
2530
2531
2532 static void __exit netif_exit(void)
2533 {
2534 xenbus_unregister_driver(&netfront_driver);
2535 }
2536 module_exit(netif_exit);
2537
2538 MODULE_DESCRIPTION("Xen virtual network device frontend");
2539 MODULE_LICENSE("GPL");
2540 MODULE_ALIAS("xen:vif");
2541 MODULE_ALIAS("xennet");
Linux with added FPC-III support