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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
48#include <asm/xen/page.h>
49#include <xen/xen.h>
50#include <xen/xenbus.h>
51#include <xen/events.h>
52#include <xen/page.h>
53#include <xen/platform_pci.h>
54#include <xen/grant_table.h>
55
56#include <xen/interface/io/netif.h>
57#include <xen/interface/memory.h>
58#include <xen/interface/grant_table.h>
59
60static const struct ethtool_ops xennet_ethtool_ops;
61
62struct netfront_cb {
63 int pull_to;
64};
65
66#define NETFRONT_SKB_CB(skb) ((struct netfront_cb *)((skb)->cb))
67
68#define RX_COPY_THRESHOLD 256
69
70#define GRANT_INVALID_REF 0
71
72#define NET_TX_RING_SIZE __CONST_RING_SIZE(xen_netif_tx, PAGE_SIZE)
73#define NET_RX_RING_SIZE __CONST_RING_SIZE(xen_netif_rx, PAGE_SIZE)
74#define TX_MAX_TARGET min_t(int, NET_TX_RING_SIZE, 256)
75
76struct netfront_stats {
77 u64 rx_packets;
78 u64 tx_packets;
79 u64 rx_bytes;
80 u64 tx_bytes;
81 struct u64_stats_sync syncp;
82};
83
84struct netfront_info {
85 struct list_head list;
86 struct net_device *netdev;
87
88 struct napi_struct napi;
89
90 /* Split event channels support, tx_* == rx_* when using
91 * single event channel.
92 */
93 unsigned int tx_evtchn, rx_evtchn;
94 unsigned int tx_irq, rx_irq;
95 /* Only used when split event channels support is enabled */
96 char tx_irq_name[IFNAMSIZ+4]; /* DEVNAME-tx */
97 char rx_irq_name[IFNAMSIZ+4]; /* DEVNAME-rx */
98
99 struct xenbus_device *xbdev;
100
101 spinlock_t tx_lock;
102 struct xen_netif_tx_front_ring tx;
103 int tx_ring_ref;
104
105 /*
106 * {tx,rx}_skbs store outstanding skbuffs. Free tx_skb entries
107 * are linked from tx_skb_freelist through skb_entry.link.
108 *
109 * NB. Freelist index entries are always going to be less than
110 * PAGE_OFFSET, whereas pointers to skbs will always be equal or
111 * greater than PAGE_OFFSET: we use this property to distinguish
112 * them.
113 */
114 union skb_entry {
115 struct sk_buff *skb;
116 unsigned long link;
117 } tx_skbs[NET_TX_RING_SIZE];
118 grant_ref_t gref_tx_head;
119 grant_ref_t grant_tx_ref[NET_TX_RING_SIZE];
120 struct page *grant_tx_page[NET_TX_RING_SIZE];
121 unsigned tx_skb_freelist;
122
123 spinlock_t rx_lock ____cacheline_aligned_in_smp;
124 struct xen_netif_rx_front_ring rx;
125 int rx_ring_ref;
126
127 /* Receive-ring batched refills. */
128#define RX_MIN_TARGET 8
129#define RX_DFL_MIN_TARGET 64
130#define RX_MAX_TARGET min_t(int, NET_RX_RING_SIZE, 256)
131 unsigned rx_min_target, rx_max_target, rx_target;
132 struct sk_buff_head rx_batch;
133
134 struct timer_list rx_refill_timer;
135
136 struct sk_buff *rx_skbs[NET_RX_RING_SIZE];
137 grant_ref_t gref_rx_head;
138 grant_ref_t grant_rx_ref[NET_RX_RING_SIZE];
139
140 unsigned long rx_pfn_array[NET_RX_RING_SIZE];
141 struct multicall_entry rx_mcl[NET_RX_RING_SIZE+1];
142 struct mmu_update rx_mmu[NET_RX_RING_SIZE];
143
144 /* Statistics */
145 struct netfront_stats __percpu *stats;
146
147 unsigned long rx_gso_checksum_fixup;
148};
149
150struct netfront_rx_info {
151 struct xen_netif_rx_response rx;
152 struct xen_netif_extra_info extras[XEN_NETIF_EXTRA_TYPE_MAX - 1];
153};
154
155static void skb_entry_set_link(union skb_entry *list, unsigned short id)
156{
157 list->link = id;
158}
159
160static int skb_entry_is_link(const union skb_entry *list)
161{
162 BUILD_BUG_ON(sizeof(list->skb) != sizeof(list->link));
163 return (unsigned long)list->skb < PAGE_OFFSET;
164}
165
166/*
167 * Access macros for acquiring freeing slots in tx_skbs[].
168 */
169
170static void add_id_to_freelist(unsigned *head, union skb_entry *list,
171 unsigned short id)
172{
173 skb_entry_set_link(&list[id], *head);
174 *head = id;
175}
176
177static unsigned short get_id_from_freelist(unsigned *head,
178 union skb_entry *list)
179{
180 unsigned int id = *head;
181 *head = list[id].link;
182 return id;
183}
184
185static int xennet_rxidx(RING_IDX idx)
186{
187 return idx & (NET_RX_RING_SIZE - 1);
188}
189
190static struct sk_buff *xennet_get_rx_skb(struct netfront_info *np,
191 RING_IDX ri)
192{
193 int i = xennet_rxidx(ri);
194 struct sk_buff *skb = np->rx_skbs[i];
195 np->rx_skbs[i] = NULL;
196 return skb;
197}
198
199static grant_ref_t xennet_get_rx_ref(struct netfront_info *np,
200 RING_IDX ri)
201{
202 int i = xennet_rxidx(ri);
203 grant_ref_t ref = np->grant_rx_ref[i];
204 np->grant_rx_ref[i] = GRANT_INVALID_REF;
205 return ref;
206}
207
208#ifdef CONFIG_SYSFS
209static int xennet_sysfs_addif(struct net_device *netdev);
210static void xennet_sysfs_delif(struct net_device *netdev);
211#else /* !CONFIG_SYSFS */
212#define xennet_sysfs_addif(dev) (0)
213#define xennet_sysfs_delif(dev) do { } while (0)
214#endif
215
216static bool xennet_can_sg(struct net_device *dev)
217{
218 return dev->features & NETIF_F_SG;
219}
220
221
222static void rx_refill_timeout(unsigned long data)
223{
224 struct net_device *dev = (struct net_device *)data;
225 struct netfront_info *np = netdev_priv(dev);
226 napi_schedule(&np->napi);
227}
228
229static int netfront_tx_slot_available(struct netfront_info *np)
230{
231 return (np->tx.req_prod_pvt - np->tx.rsp_cons) <
232 (TX_MAX_TARGET - MAX_SKB_FRAGS - 2);
233}
234
235static void xennet_maybe_wake_tx(struct net_device *dev)
236{
237 struct netfront_info *np = netdev_priv(dev);
238
239 if (unlikely(netif_queue_stopped(dev)) &&
240 netfront_tx_slot_available(np) &&
241 likely(netif_running(dev)))
242 netif_wake_queue(dev);
243}
244
245static void xennet_alloc_rx_buffers(struct net_device *dev)
246{
247 unsigned short id;
248 struct netfront_info *np = netdev_priv(dev);
249 struct sk_buff *skb;
250 struct page *page;
251 int i, batch_target, notify;
252 RING_IDX req_prod = np->rx.req_prod_pvt;
253 grant_ref_t ref;
254 unsigned long pfn;
255 void *vaddr;
256 struct xen_netif_rx_request *req;
257
258 if (unlikely(!netif_carrier_ok(dev)))
259 return;
260
261 /*
262 * Allocate skbuffs greedily, even though we batch updates to the
263 * receive ring. This creates a less bursty demand on the memory
264 * allocator, so should reduce the chance of failed allocation requests
265 * both for ourself and for other kernel subsystems.
266 */
267 batch_target = np->rx_target - (req_prod - np->rx.rsp_cons);
268 for (i = skb_queue_len(&np->rx_batch); i < batch_target; i++) {
269 skb = __netdev_alloc_skb(dev, RX_COPY_THRESHOLD + NET_IP_ALIGN,
270 GFP_ATOMIC | __GFP_NOWARN);
271 if (unlikely(!skb))
272 goto no_skb;
273
274 /* Align ip header to a 16 bytes boundary */
275 skb_reserve(skb, NET_IP_ALIGN);
276
277 page = alloc_page(GFP_ATOMIC | __GFP_NOWARN);
278 if (!page) {
279 kfree_skb(skb);
280no_skb:
281 /* Could not allocate any skbuffs. Try again later. */
282 mod_timer(&np->rx_refill_timer,
283 jiffies + (HZ/10));
284
285 /* Any skbuffs queued for refill? Force them out. */
286 if (i != 0)
287 goto refill;
288 break;
289 }
290
291 skb_add_rx_frag(skb, 0, page, 0, 0, PAGE_SIZE);
292 __skb_queue_tail(&np->rx_batch, skb);
293 }
294
295 /* Is the batch large enough to be worthwhile? */
296 if (i < (np->rx_target/2)) {
297 if (req_prod > np->rx.sring->req_prod)
298 goto push;
299 return;
300 }
301
302 /* Adjust our fill target if we risked running out of buffers. */
303 if (((req_prod - np->rx.sring->rsp_prod) < (np->rx_target / 4)) &&
304 ((np->rx_target *= 2) > np->rx_max_target))
305 np->rx_target = np->rx_max_target;
306
307 refill:
308 for (i = 0; ; i++) {
309 skb = __skb_dequeue(&np->rx_batch);
310 if (skb == NULL)
311 break;
312
313 skb->dev = dev;
314
315 id = xennet_rxidx(req_prod + i);
316
317 BUG_ON(np->rx_skbs[id]);
318 np->rx_skbs[id] = skb;
319
320 ref = gnttab_claim_grant_reference(&np->gref_rx_head);
321 BUG_ON((signed short)ref < 0);
322 np->grant_rx_ref[id] = ref;
323
324 pfn = page_to_pfn(skb_frag_page(&skb_shinfo(skb)->frags[0]));
325 vaddr = page_address(skb_frag_page(&skb_shinfo(skb)->frags[0]));
326
327 req = RING_GET_REQUEST(&np->rx, req_prod + i);
328 gnttab_grant_foreign_access_ref(ref,
329 np->xbdev->otherend_id,
330 pfn_to_mfn(pfn),
331 0);
332
333 req->id = id;
334 req->gref = ref;
335 }
336
337 wmb(); /* barrier so backend seens requests */
338
339 /* Above is a suitable barrier to ensure backend will see requests. */
340 np->rx.req_prod_pvt = req_prod + i;
341 push:
342 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&np->rx, notify);
343 if (notify)
344 notify_remote_via_irq(np->rx_irq);
345}
346
347static int xennet_open(struct net_device *dev)
348{
349 struct netfront_info *np = netdev_priv(dev);
350
351 napi_enable(&np->napi);
352
353 spin_lock_bh(&np->rx_lock);
354 if (netif_carrier_ok(dev)) {
355 xennet_alloc_rx_buffers(dev);
356 np->rx.sring->rsp_event = np->rx.rsp_cons + 1;
357 if (RING_HAS_UNCONSUMED_RESPONSES(&np->rx))
358 napi_schedule(&np->napi);
359 }
360 spin_unlock_bh(&np->rx_lock);
361
362 netif_start_queue(dev);
363
364 return 0;
365}
366
367static void xennet_tx_buf_gc(struct net_device *dev)
368{
369 RING_IDX cons, prod;
370 unsigned short id;
371 struct netfront_info *np = netdev_priv(dev);
372 struct sk_buff *skb;
373
374 BUG_ON(!netif_carrier_ok(dev));
375
376 do {
377 prod = np->tx.sring->rsp_prod;
378 rmb(); /* Ensure we see responses up to 'rp'. */
379
380 for (cons = np->tx.rsp_cons; cons != prod; cons++) {
381 struct xen_netif_tx_response *txrsp;
382
383 txrsp = RING_GET_RESPONSE(&np->tx, cons);
384 if (txrsp->status == XEN_NETIF_RSP_NULL)
385 continue;
386
387 id = txrsp->id;
388 skb = np->tx_skbs[id].skb;
389 if (unlikely(gnttab_query_foreign_access(
390 np->grant_tx_ref[id]) != 0)) {
391 pr_alert("%s: warning -- grant still in use by backend domain\n",
392 __func__);
393 BUG();
394 }
395 gnttab_end_foreign_access_ref(
396 np->grant_tx_ref[id], GNTMAP_readonly);
397 gnttab_release_grant_reference(
398 &np->gref_tx_head, np->grant_tx_ref[id]);
399 np->grant_tx_ref[id] = GRANT_INVALID_REF;
400 np->grant_tx_page[id] = NULL;
401 add_id_to_freelist(&np->tx_skb_freelist, np->tx_skbs, id);
402 dev_kfree_skb_irq(skb);
403 }
404
405 np->tx.rsp_cons = prod;
406
407 /*
408 * Set a new event, then check for race with update of tx_cons.
409 * Note that it is essential to schedule a callback, no matter
410 * how few buffers are pending. Even if there is space in the
411 * transmit ring, higher layers may be blocked because too much
412 * data is outstanding: in such cases notification from Xen is
413 * likely to be the only kick that we'll get.
414 */
415 np->tx.sring->rsp_event =
416 prod + ((np->tx.sring->req_prod - prod) >> 1) + 1;
417 mb(); /* update shared area */
418 } while ((cons == prod) && (prod != np->tx.sring->rsp_prod));
419
420 xennet_maybe_wake_tx(dev);
421}
422
423static void xennet_make_frags(struct sk_buff *skb, struct net_device *dev,
424 struct xen_netif_tx_request *tx)
425{
426 struct netfront_info *np = netdev_priv(dev);
427 char *data = skb->data;
428 unsigned long mfn;
429 RING_IDX prod = np->tx.req_prod_pvt;
430 int frags = skb_shinfo(skb)->nr_frags;
431 unsigned int offset = offset_in_page(data);
432 unsigned int len = skb_headlen(skb);
433 unsigned int id;
434 grant_ref_t ref;
435 int i;
436
437 /* While the header overlaps a page boundary (including being
438 larger than a page), split it it into page-sized chunks. */
439 while (len > PAGE_SIZE - offset) {
440 tx->size = PAGE_SIZE - offset;
441 tx->flags |= XEN_NETTXF_more_data;
442 len -= tx->size;
443 data += tx->size;
444 offset = 0;
445
446 id = get_id_from_freelist(&np->tx_skb_freelist, np->tx_skbs);
447 np->tx_skbs[id].skb = skb_get(skb);
448 tx = RING_GET_REQUEST(&np->tx, prod++);
449 tx->id = id;
450 ref = gnttab_claim_grant_reference(&np->gref_tx_head);
451 BUG_ON((signed short)ref < 0);
452
453 mfn = virt_to_mfn(data);
454 gnttab_grant_foreign_access_ref(ref, np->xbdev->otherend_id,
455 mfn, GNTMAP_readonly);
456
457 np->grant_tx_page[id] = virt_to_page(data);
458 tx->gref = np->grant_tx_ref[id] = ref;
459 tx->offset = offset;
460 tx->size = len;
461 tx->flags = 0;
462 }
463
464 /* Grant backend access to each skb fragment page. */
465 for (i = 0; i < frags; i++) {
466 skb_frag_t *frag = skb_shinfo(skb)->frags + i;
467 struct page *page = skb_frag_page(frag);
468
469 len = skb_frag_size(frag);
470 offset = frag->page_offset;
471
472 /* Data must not cross a page boundary. */
473 BUG_ON(len + offset > PAGE_SIZE<<compound_order(page));
474
475 /* Skip unused frames from start of page */
476 page += offset >> PAGE_SHIFT;
477 offset &= ~PAGE_MASK;
478
479 while (len > 0) {
480 unsigned long bytes;
481
482 BUG_ON(offset >= PAGE_SIZE);
483
484 bytes = PAGE_SIZE - offset;
485 if (bytes > len)
486 bytes = len;
487
488 tx->flags |= XEN_NETTXF_more_data;
489
490 id = get_id_from_freelist(&np->tx_skb_freelist,
491 np->tx_skbs);
492 np->tx_skbs[id].skb = skb_get(skb);
493 tx = RING_GET_REQUEST(&np->tx, prod++);
494 tx->id = id;
495 ref = gnttab_claim_grant_reference(&np->gref_tx_head);
496 BUG_ON((signed short)ref < 0);
497
498 mfn = pfn_to_mfn(page_to_pfn(page));
499 gnttab_grant_foreign_access_ref(ref,
500 np->xbdev->otherend_id,
501 mfn, GNTMAP_readonly);
502
503 np->grant_tx_page[id] = page;
504 tx->gref = np->grant_tx_ref[id] = ref;
505 tx->offset = offset;
506 tx->size = bytes;
507 tx->flags = 0;
508
509 offset += bytes;
510 len -= bytes;
511
512 /* Next frame */
513 if (offset == PAGE_SIZE && len) {
514 BUG_ON(!PageCompound(page));
515 page++;
516 offset = 0;
517 }
518 }
519 }
520
521 np->tx.req_prod_pvt = prod;
522}
523
524/*
525 * Count how many ring slots are required to send the frags of this
526 * skb. Each frag might be a compound page.
527 */
528static int xennet_count_skb_frag_slots(struct sk_buff *skb)
529{
530 int i, frags = skb_shinfo(skb)->nr_frags;
531 int pages = 0;
532
533 for (i = 0; i < frags; i++) {
534 skb_frag_t *frag = skb_shinfo(skb)->frags + i;
535 unsigned long size = skb_frag_size(frag);
536 unsigned long offset = frag->page_offset;
537
538 /* Skip unused frames from start of page */
539 offset &= ~PAGE_MASK;
540
541 pages += PFN_UP(offset + size);
542 }
543
544 return pages;
545}
546
547static int xennet_start_xmit(struct sk_buff *skb, struct net_device *dev)
548{
549 unsigned short id;
550 struct netfront_info *np = netdev_priv(dev);
551 struct netfront_stats *stats = this_cpu_ptr(np->stats);
552 struct xen_netif_tx_request *tx;
553 char *data = skb->data;
554 RING_IDX i;
555 grant_ref_t ref;
556 unsigned long mfn;
557 int notify;
558 int slots;
559 unsigned int offset = offset_in_page(data);
560 unsigned int len = skb_headlen(skb);
561 unsigned long flags;
562
563 /* If skb->len is too big for wire format, drop skb and alert
564 * user about misconfiguration.
565 */
566 if (unlikely(skb->len > XEN_NETIF_MAX_TX_SIZE)) {
567 net_alert_ratelimited(
568 "xennet: skb->len = %u, too big for wire format\n",
569 skb->len);
570 goto drop;
571 }
572
573 slots = DIV_ROUND_UP(offset + len, PAGE_SIZE) +
574 xennet_count_skb_frag_slots(skb);
575 if (unlikely(slots > MAX_SKB_FRAGS + 1)) {
576 net_alert_ratelimited(
577 "xennet: skb rides the rocket: %d slots\n", slots);
578 goto drop;
579 }
580
581 spin_lock_irqsave(&np->tx_lock, flags);
582
583 if (unlikely(!netif_carrier_ok(dev) ||
584 (slots > 1 && !xennet_can_sg(dev)) ||
585 netif_needs_gso(skb, netif_skb_features(skb)))) {
586 spin_unlock_irqrestore(&np->tx_lock, flags);
587 goto drop;
588 }
589
590 i = np->tx.req_prod_pvt;
591
592 id = get_id_from_freelist(&np->tx_skb_freelist, np->tx_skbs);
593 np->tx_skbs[id].skb = skb;
594
595 tx = RING_GET_REQUEST(&np->tx, i);
596
597 tx->id = id;
598 ref = gnttab_claim_grant_reference(&np->gref_tx_head);
599 BUG_ON((signed short)ref < 0);
600 mfn = virt_to_mfn(data);
601 gnttab_grant_foreign_access_ref(
602 ref, np->xbdev->otherend_id, mfn, GNTMAP_readonly);
603 np->grant_tx_page[id] = virt_to_page(data);
604 tx->gref = np->grant_tx_ref[id] = ref;
605 tx->offset = offset;
606 tx->size = len;
607
608 tx->flags = 0;
609 if (skb->ip_summed == CHECKSUM_PARTIAL)
610 /* local packet? */
611 tx->flags |= XEN_NETTXF_csum_blank | XEN_NETTXF_data_validated;
612 else if (skb->ip_summed == CHECKSUM_UNNECESSARY)
613 /* remote but checksummed. */
614 tx->flags |= XEN_NETTXF_data_validated;
615
616 if (skb_shinfo(skb)->gso_size) {
617 struct xen_netif_extra_info *gso;
618
619 gso = (struct xen_netif_extra_info *)
620 RING_GET_REQUEST(&np->tx, ++i);
621
622 tx->flags |= XEN_NETTXF_extra_info;
623
624 gso->u.gso.size = skb_shinfo(skb)->gso_size;
625 gso->u.gso.type = (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6) ?
626 XEN_NETIF_GSO_TYPE_TCPV6 :
627 XEN_NETIF_GSO_TYPE_TCPV4;
628 gso->u.gso.pad = 0;
629 gso->u.gso.features = 0;
630
631 gso->type = XEN_NETIF_EXTRA_TYPE_GSO;
632 gso->flags = 0;
633 }
634
635 np->tx.req_prod_pvt = i + 1;
636
637 xennet_make_frags(skb, dev, tx);
638 tx->size = skb->len;
639
640 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&np->tx, notify);
641 if (notify)
642 notify_remote_via_irq(np->tx_irq);
643
644 u64_stats_update_begin(&stats->syncp);
645 stats->tx_bytes += skb->len;
646 stats->tx_packets++;
647 u64_stats_update_end(&stats->syncp);
648
649 /* Note: It is not safe to access skb after xennet_tx_buf_gc()! */
650 xennet_tx_buf_gc(dev);
651
652 if (!netfront_tx_slot_available(np))
653 netif_stop_queue(dev);
654
655 spin_unlock_irqrestore(&np->tx_lock, flags);
656
657 return NETDEV_TX_OK;
658
659 drop:
660 dev->stats.tx_dropped++;
661 dev_kfree_skb_any(skb);
662 return NETDEV_TX_OK;
663}
664
665static int xennet_close(struct net_device *dev)
666{
667 struct netfront_info *np = netdev_priv(dev);
668 netif_stop_queue(np->netdev);
669 napi_disable(&np->napi);
670 return 0;
671}
672
673static void xennet_move_rx_slot(struct netfront_info *np, struct sk_buff *skb,
674 grant_ref_t ref)
675{
676 int new = xennet_rxidx(np->rx.req_prod_pvt);
677
678 BUG_ON(np->rx_skbs[new]);
679 np->rx_skbs[new] = skb;
680 np->grant_rx_ref[new] = ref;
681 RING_GET_REQUEST(&np->rx, np->rx.req_prod_pvt)->id = new;
682 RING_GET_REQUEST(&np->rx, np->rx.req_prod_pvt)->gref = ref;
683 np->rx.req_prod_pvt++;
684}
685
686static int xennet_get_extras(struct netfront_info *np,
687 struct xen_netif_extra_info *extras,
688 RING_IDX rp)
689
690{
691 struct xen_netif_extra_info *extra;
692 struct device *dev = &np->netdev->dev;
693 RING_IDX cons = np->rx.rsp_cons;
694 int err = 0;
695
696 do {
697 struct sk_buff *skb;
698 grant_ref_t ref;
699
700 if (unlikely(cons + 1 == rp)) {
701 if (net_ratelimit())
702 dev_warn(dev, "Missing extra info\n");
703 err = -EBADR;
704 break;
705 }
706
707 extra = (struct xen_netif_extra_info *)
708 RING_GET_RESPONSE(&np->rx, ++cons);
709
710 if (unlikely(!extra->type ||
711 extra->type >= XEN_NETIF_EXTRA_TYPE_MAX)) {
712 if (net_ratelimit())
713 dev_warn(dev, "Invalid extra type: %d\n",
714 extra->type);
715 err = -EINVAL;
716 } else {
717 memcpy(&extras[extra->type - 1], extra,
718 sizeof(*extra));
719 }
720
721 skb = xennet_get_rx_skb(np, cons);
722 ref = xennet_get_rx_ref(np, cons);
723 xennet_move_rx_slot(np, skb, ref);
724 } while (extra->flags & XEN_NETIF_EXTRA_FLAG_MORE);
725
726 np->rx.rsp_cons = cons;
727 return err;
728}
729
730static int xennet_get_responses(struct netfront_info *np,
731 struct netfront_rx_info *rinfo, RING_IDX rp,
732 struct sk_buff_head *list)
733{
734 struct xen_netif_rx_response *rx = &rinfo->rx;
735 struct xen_netif_extra_info *extras = rinfo->extras;
736 struct device *dev = &np->netdev->dev;
737 RING_IDX cons = np->rx.rsp_cons;
738 struct sk_buff *skb = xennet_get_rx_skb(np, cons);
739 grant_ref_t ref = xennet_get_rx_ref(np, cons);
740 int max = MAX_SKB_FRAGS + (rx->status <= RX_COPY_THRESHOLD);
741 int slots = 1;
742 int err = 0;
743 unsigned long ret;
744
745 if (rx->flags & XEN_NETRXF_extra_info) {
746 err = xennet_get_extras(np, extras, rp);
747 cons = np->rx.rsp_cons;
748 }
749
750 for (;;) {
751 if (unlikely(rx->status < 0 ||
752 rx->offset + rx->status > PAGE_SIZE)) {
753 if (net_ratelimit())
754 dev_warn(dev, "rx->offset: %x, size: %u\n",
755 rx->offset, rx->status);
756 xennet_move_rx_slot(np, skb, ref);
757 err = -EINVAL;
758 goto next;
759 }
760
761 /*
762 * This definitely indicates a bug, either in this driver or in
763 * the backend driver. In future this should flag the bad
764 * situation to the system controller to reboot the backend.
765 */
766 if (ref == GRANT_INVALID_REF) {
767 if (net_ratelimit())
768 dev_warn(dev, "Bad rx response id %d.\n",
769 rx->id);
770 err = -EINVAL;
771 goto next;
772 }
773
774 ret = gnttab_end_foreign_access_ref(ref, 0);
775 BUG_ON(!ret);
776
777 gnttab_release_grant_reference(&np->gref_rx_head, ref);
778
779 __skb_queue_tail(list, skb);
780
781next:
782 if (!(rx->flags & XEN_NETRXF_more_data))
783 break;
784
785 if (cons + slots == rp) {
786 if (net_ratelimit())
787 dev_warn(dev, "Need more slots\n");
788 err = -ENOENT;
789 break;
790 }
791
792 rx = RING_GET_RESPONSE(&np->rx, cons + slots);
793 skb = xennet_get_rx_skb(np, cons + slots);
794 ref = xennet_get_rx_ref(np, cons + slots);
795 slots++;
796 }
797
798 if (unlikely(slots > max)) {
799 if (net_ratelimit())
800 dev_warn(dev, "Too many slots\n");
801 err = -E2BIG;
802 }
803
804 if (unlikely(err))
805 np->rx.rsp_cons = cons + slots;
806
807 return err;
808}
809
810static int xennet_set_skb_gso(struct sk_buff *skb,
811 struct xen_netif_extra_info *gso)
812{
813 if (!gso->u.gso.size) {
814 if (net_ratelimit())
815 pr_warn("GSO size must not be zero\n");
816 return -EINVAL;
817 }
818
819 if (gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV4 &&
820 gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV6) {
821 if (net_ratelimit())
822 pr_warn("Bad GSO type %d\n", gso->u.gso.type);
823 return -EINVAL;
824 }
825
826 skb_shinfo(skb)->gso_size = gso->u.gso.size;
827 skb_shinfo(skb)->gso_type =
828 (gso->u.gso.type == XEN_NETIF_GSO_TYPE_TCPV4) ?
829 SKB_GSO_TCPV4 :
830 SKB_GSO_TCPV6;
831
832 /* Header must be checked, and gso_segs computed. */
833 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
834 skb_shinfo(skb)->gso_segs = 0;
835
836 return 0;
837}
838
839static RING_IDX xennet_fill_frags(struct netfront_info *np,
840 struct sk_buff *skb,
841 struct sk_buff_head *list)
842{
843 struct skb_shared_info *shinfo = skb_shinfo(skb);
844 RING_IDX cons = np->rx.rsp_cons;
845 struct sk_buff *nskb;
846
847 while ((nskb = __skb_dequeue(list))) {
848 struct xen_netif_rx_response *rx =
849 RING_GET_RESPONSE(&np->rx, ++cons);
850 skb_frag_t *nfrag = &skb_shinfo(nskb)->frags[0];
851
852 if (shinfo->nr_frags == MAX_SKB_FRAGS) {
853 unsigned int pull_to = NETFRONT_SKB_CB(skb)->pull_to;
854
855 BUG_ON(pull_to <= skb_headlen(skb));
856 __pskb_pull_tail(skb, pull_to - skb_headlen(skb));
857 }
858 BUG_ON(shinfo->nr_frags >= MAX_SKB_FRAGS);
859
860 skb_add_rx_frag(skb, shinfo->nr_frags, skb_frag_page(nfrag),
861 rx->offset, rx->status, PAGE_SIZE);
862
863 skb_shinfo(nskb)->nr_frags = 0;
864 kfree_skb(nskb);
865 }
866
867 return cons;
868}
869
870static int checksum_setup(struct net_device *dev, struct sk_buff *skb)
871{
872 bool recalculate_partial_csum = false;
873
874 /*
875 * A GSO SKB must be CHECKSUM_PARTIAL. However some buggy
876 * peers can fail to set NETRXF_csum_blank when sending a GSO
877 * frame. In this case force the SKB to CHECKSUM_PARTIAL and
878 * recalculate the partial checksum.
879 */
880 if (skb->ip_summed != CHECKSUM_PARTIAL && skb_is_gso(skb)) {
881 struct netfront_info *np = netdev_priv(dev);
882 np->rx_gso_checksum_fixup++;
883 skb->ip_summed = CHECKSUM_PARTIAL;
884 recalculate_partial_csum = true;
885 }
886
887 /* A non-CHECKSUM_PARTIAL SKB does not require setup. */
888 if (skb->ip_summed != CHECKSUM_PARTIAL)
889 return 0;
890
891 return skb_checksum_setup(skb, recalculate_partial_csum);
892}
893
894static int handle_incoming_queue(struct net_device *dev,
895 struct sk_buff_head *rxq)
896{
897 struct netfront_info *np = netdev_priv(dev);
898 struct netfront_stats *stats = this_cpu_ptr(np->stats);
899 int packets_dropped = 0;
900 struct sk_buff *skb;
901
902 while ((skb = __skb_dequeue(rxq)) != NULL) {
903 int pull_to = NETFRONT_SKB_CB(skb)->pull_to;
904
905 if (pull_to > skb_headlen(skb))
906 __pskb_pull_tail(skb, pull_to - skb_headlen(skb));
907
908 /* Ethernet work: Delayed to here as it peeks the header. */
909 skb->protocol = eth_type_trans(skb, dev);
910 skb_reset_network_header(skb);
911
912 if (checksum_setup(dev, skb)) {
913 kfree_skb(skb);
914 packets_dropped++;
915 dev->stats.rx_errors++;
916 continue;
917 }
918
919 u64_stats_update_begin(&stats->syncp);
920 stats->rx_packets++;
921 stats->rx_bytes += skb->len;
922 u64_stats_update_end(&stats->syncp);
923
924 /* Pass it up. */
925 napi_gro_receive(&np->napi, skb);
926 }
927
928 return packets_dropped;
929}
930
931static int xennet_poll(struct napi_struct *napi, int budget)
932{
933 struct netfront_info *np = container_of(napi, struct netfront_info, napi);
934 struct net_device *dev = np->netdev;
935 struct sk_buff *skb;
936 struct netfront_rx_info rinfo;
937 struct xen_netif_rx_response *rx = &rinfo.rx;
938 struct xen_netif_extra_info *extras = rinfo.extras;
939 RING_IDX i, rp;
940 int work_done;
941 struct sk_buff_head rxq;
942 struct sk_buff_head errq;
943 struct sk_buff_head tmpq;
944 unsigned long flags;
945 int err;
946
947 spin_lock(&np->rx_lock);
948
949 skb_queue_head_init(&rxq);
950 skb_queue_head_init(&errq);
951 skb_queue_head_init(&tmpq);
952
953 rp = np->rx.sring->rsp_prod;
954 rmb(); /* Ensure we see queued responses up to 'rp'. */
955
956 i = np->rx.rsp_cons;
957 work_done = 0;
958 while ((i != rp) && (work_done < budget)) {
959 memcpy(rx, RING_GET_RESPONSE(&np->rx, i), sizeof(*rx));
960 memset(extras, 0, sizeof(rinfo.extras));
961
962 err = xennet_get_responses(np, &rinfo, rp, &tmpq);
963
964 if (unlikely(err)) {
965err:
966 while ((skb = __skb_dequeue(&tmpq)))
967 __skb_queue_tail(&errq, skb);
968 dev->stats.rx_errors++;
969 i = np->rx.rsp_cons;
970 continue;
971 }
972
973 skb = __skb_dequeue(&tmpq);
974
975 if (extras[XEN_NETIF_EXTRA_TYPE_GSO - 1].type) {
976 struct xen_netif_extra_info *gso;
977 gso = &extras[XEN_NETIF_EXTRA_TYPE_GSO - 1];
978
979 if (unlikely(xennet_set_skb_gso(skb, gso))) {
980 __skb_queue_head(&tmpq, skb);
981 np->rx.rsp_cons += skb_queue_len(&tmpq);
982 goto err;
983 }
984 }
985
986 NETFRONT_SKB_CB(skb)->pull_to = rx->status;
987 if (NETFRONT_SKB_CB(skb)->pull_to > RX_COPY_THRESHOLD)
988 NETFRONT_SKB_CB(skb)->pull_to = RX_COPY_THRESHOLD;
989
990 skb_shinfo(skb)->frags[0].page_offset = rx->offset;
991 skb_frag_size_set(&skb_shinfo(skb)->frags[0], rx->status);
992 skb->data_len = rx->status;
993 skb->len += rx->status;
994
995 i = xennet_fill_frags(np, skb, &tmpq);
996
997 if (rx->flags & XEN_NETRXF_csum_blank)
998 skb->ip_summed = CHECKSUM_PARTIAL;
999 else if (rx->flags & XEN_NETRXF_data_validated)
1000 skb->ip_summed = CHECKSUM_UNNECESSARY;
1001
1002 __skb_queue_tail(&rxq, skb);
1003
1004 np->rx.rsp_cons = ++i;
1005 work_done++;
1006 }
1007
1008 __skb_queue_purge(&errq);
1009
1010 work_done -= handle_incoming_queue(dev, &rxq);
1011
1012 /* If we get a callback with very few responses, reduce fill target. */
1013 /* NB. Note exponential increase, linear decrease. */
1014 if (((np->rx.req_prod_pvt - np->rx.sring->rsp_prod) >
1015 ((3*np->rx_target) / 4)) &&
1016 (--np->rx_target < np->rx_min_target))
1017 np->rx_target = np->rx_min_target;
1018
1019 xennet_alloc_rx_buffers(dev);
1020
1021 if (work_done < budget) {
1022 int more_to_do = 0;
1023
1024 napi_gro_flush(napi, false);
1025
1026 local_irq_save(flags);
1027
1028 RING_FINAL_CHECK_FOR_RESPONSES(&np->rx, more_to_do);
1029 if (!more_to_do)
1030 __napi_complete(napi);
1031
1032 local_irq_restore(flags);
1033 }
1034
1035 spin_unlock(&np->rx_lock);
1036
1037 return work_done;
1038}
1039
1040static int xennet_change_mtu(struct net_device *dev, int mtu)
1041{
1042 int max = xennet_can_sg(dev) ?
1043 XEN_NETIF_MAX_TX_SIZE - MAX_TCP_HEADER : ETH_DATA_LEN;
1044
1045 if (mtu > max)
1046 return -EINVAL;
1047 dev->mtu = mtu;
1048 return 0;
1049}
1050
1051static struct rtnl_link_stats64 *xennet_get_stats64(struct net_device *dev,
1052 struct rtnl_link_stats64 *tot)
1053{
1054 struct netfront_info *np = netdev_priv(dev);
1055 int cpu;
1056
1057 for_each_possible_cpu(cpu) {
1058 struct netfront_stats *stats = per_cpu_ptr(np->stats, cpu);
1059 u64 rx_packets, rx_bytes, tx_packets, tx_bytes;
1060 unsigned int start;
1061
1062 do {
1063 start = u64_stats_fetch_begin_irq(&stats->syncp);
1064
1065 rx_packets = stats->rx_packets;
1066 tx_packets = stats->tx_packets;
1067 rx_bytes = stats->rx_bytes;
1068 tx_bytes = stats->tx_bytes;
1069 } while (u64_stats_fetch_retry_irq(&stats->syncp, start));
1070
1071 tot->rx_packets += rx_packets;
1072 tot->tx_packets += tx_packets;
1073 tot->rx_bytes += rx_bytes;
1074 tot->tx_bytes += tx_bytes;
1075 }
1076
1077 tot->rx_errors = dev->stats.rx_errors;
1078 tot->tx_dropped = dev->stats.tx_dropped;
1079
1080 return tot;
1081}
1082
1083static void xennet_release_tx_bufs(struct netfront_info *np)
1084{
1085 struct sk_buff *skb;
1086 int i;
1087
1088 for (i = 0; i < NET_TX_RING_SIZE; i++) {
1089 /* Skip over entries which are actually freelist references */
1090 if (skb_entry_is_link(&np->tx_skbs[i]))
1091 continue;
1092
1093 skb = np->tx_skbs[i].skb;
1094 get_page(np->grant_tx_page[i]);
1095 gnttab_end_foreign_access(np->grant_tx_ref[i],
1096 GNTMAP_readonly,
1097 (unsigned long)page_address(np->grant_tx_page[i]));
1098 np->grant_tx_page[i] = NULL;
1099 np->grant_tx_ref[i] = GRANT_INVALID_REF;
1100 add_id_to_freelist(&np->tx_skb_freelist, np->tx_skbs, i);
1101 dev_kfree_skb_irq(skb);
1102 }
1103}
1104
1105static void xennet_release_rx_bufs(struct netfront_info *np)
1106{
1107 int id, ref;
1108
1109 spin_lock_bh(&np->rx_lock);
1110
1111 for (id = 0; id < NET_RX_RING_SIZE; id++) {
1112 struct sk_buff *skb;
1113 struct page *page;
1114
1115 skb = np->rx_skbs[id];
1116 if (!skb)
1117 continue;
1118
1119 ref = np->grant_rx_ref[id];
1120 if (ref == GRANT_INVALID_REF)
1121 continue;
1122
1123 page = skb_frag_page(&skb_shinfo(skb)->frags[0]);
1124
1125 /* gnttab_end_foreign_access() needs a page ref until
1126 * foreign access is ended (which may be deferred).
1127 */
1128 get_page(page);
1129 gnttab_end_foreign_access(ref, 0,
1130 (unsigned long)page_address(page));
1131 np->grant_rx_ref[id] = GRANT_INVALID_REF;
1132
1133 kfree_skb(skb);
1134 }
1135
1136 spin_unlock_bh(&np->rx_lock);
1137}
1138
1139static void xennet_uninit(struct net_device *dev)
1140{
1141 struct netfront_info *np = netdev_priv(dev);
1142 xennet_release_tx_bufs(np);
1143 xennet_release_rx_bufs(np);
1144 gnttab_free_grant_references(np->gref_tx_head);
1145 gnttab_free_grant_references(np->gref_rx_head);
1146}
1147
1148static netdev_features_t xennet_fix_features(struct net_device *dev,
1149 netdev_features_t features)
1150{
1151 struct netfront_info *np = netdev_priv(dev);
1152 int val;
1153
1154 if (features & NETIF_F_SG) {
1155 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend, "feature-sg",
1156 "%d", &val) < 0)
1157 val = 0;
1158
1159 if (!val)
1160 features &= ~NETIF_F_SG;
1161 }
1162
1163 if (features & NETIF_F_IPV6_CSUM) {
1164 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend,
1165 "feature-ipv6-csum-offload", "%d", &val) < 0)
1166 val = 0;
1167
1168 if (!val)
1169 features &= ~NETIF_F_IPV6_CSUM;
1170 }
1171
1172 if (features & NETIF_F_TSO) {
1173 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend,
1174 "feature-gso-tcpv4", "%d", &val) < 0)
1175 val = 0;
1176
1177 if (!val)
1178 features &= ~NETIF_F_TSO;
1179 }
1180
1181 if (features & NETIF_F_TSO6) {
1182 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend,
1183 "feature-gso-tcpv6", "%d", &val) < 0)
1184 val = 0;
1185
1186 if (!val)
1187 features &= ~NETIF_F_TSO6;
1188 }
1189
1190 return features;
1191}
1192
1193static int xennet_set_features(struct net_device *dev,
1194 netdev_features_t features)
1195{
1196 if (!(features & NETIF_F_SG) && dev->mtu > ETH_DATA_LEN) {
1197 netdev_info(dev, "Reducing MTU because no SG offload");
1198 dev->mtu = ETH_DATA_LEN;
1199 }
1200
1201 return 0;
1202}
1203
1204static irqreturn_t xennet_tx_interrupt(int irq, void *dev_id)
1205{
1206 struct netfront_info *np = dev_id;
1207 struct net_device *dev = np->netdev;
1208 unsigned long flags;
1209
1210 spin_lock_irqsave(&np->tx_lock, flags);
1211 xennet_tx_buf_gc(dev);
1212 spin_unlock_irqrestore(&np->tx_lock, flags);
1213
1214 return IRQ_HANDLED;
1215}
1216
1217static irqreturn_t xennet_rx_interrupt(int irq, void *dev_id)
1218{
1219 struct netfront_info *np = dev_id;
1220 struct net_device *dev = np->netdev;
1221
1222 if (likely(netif_carrier_ok(dev) &&
1223 RING_HAS_UNCONSUMED_RESPONSES(&np->rx)))
1224 napi_schedule(&np->napi);
1225
1226 return IRQ_HANDLED;
1227}
1228
1229static irqreturn_t xennet_interrupt(int irq, void *dev_id)
1230{
1231 xennet_tx_interrupt(irq, dev_id);
1232 xennet_rx_interrupt(irq, dev_id);
1233 return IRQ_HANDLED;
1234}
1235
1236#ifdef CONFIG_NET_POLL_CONTROLLER
1237static void xennet_poll_controller(struct net_device *dev)
1238{
1239 xennet_interrupt(0, dev);
1240}
1241#endif
1242
1243static const struct net_device_ops xennet_netdev_ops = {
1244 .ndo_open = xennet_open,
1245 .ndo_uninit = xennet_uninit,
1246 .ndo_stop = xennet_close,
1247 .ndo_start_xmit = xennet_start_xmit,
1248 .ndo_change_mtu = xennet_change_mtu,
1249 .ndo_get_stats64 = xennet_get_stats64,
1250 .ndo_set_mac_address = eth_mac_addr,
1251 .ndo_validate_addr = eth_validate_addr,
1252 .ndo_fix_features = xennet_fix_features,
1253 .ndo_set_features = xennet_set_features,
1254#ifdef CONFIG_NET_POLL_CONTROLLER
1255 .ndo_poll_controller = xennet_poll_controller,
1256#endif
1257};
1258
1259static struct net_device *xennet_create_dev(struct xenbus_device *dev)
1260{
1261 int i, err;
1262 struct net_device *netdev;
1263 struct netfront_info *np;
1264
1265 netdev = alloc_etherdev(sizeof(struct netfront_info));
1266 if (!netdev)
1267 return ERR_PTR(-ENOMEM);
1268
1269 np = netdev_priv(netdev);
1270 np->xbdev = dev;
1271
1272 spin_lock_init(&np->tx_lock);
1273 spin_lock_init(&np->rx_lock);
1274
1275 skb_queue_head_init(&np->rx_batch);
1276 np->rx_target = RX_DFL_MIN_TARGET;
1277 np->rx_min_target = RX_DFL_MIN_TARGET;
1278 np->rx_max_target = RX_MAX_TARGET;
1279
1280 init_timer(&np->rx_refill_timer);
1281 np->rx_refill_timer.data = (unsigned long)netdev;
1282 np->rx_refill_timer.function = rx_refill_timeout;
1283
1284 err = -ENOMEM;
1285 np->stats = netdev_alloc_pcpu_stats(struct netfront_stats);
1286 if (np->stats == NULL)
1287 goto exit;
1288
1289 /* Initialise tx_skbs as a free chain containing every entry. */
1290 np->tx_skb_freelist = 0;
1291 for (i = 0; i < NET_TX_RING_SIZE; i++) {
1292 skb_entry_set_link(&np->tx_skbs[i], i+1);
1293 np->grant_tx_ref[i] = GRANT_INVALID_REF;
1294 np->grant_tx_page[i] = NULL;
1295 }
1296
1297 /* Clear out rx_skbs */
1298 for (i = 0; i < NET_RX_RING_SIZE; i++) {
1299 np->rx_skbs[i] = NULL;
1300 np->grant_rx_ref[i] = GRANT_INVALID_REF;
1301 }
1302
1303 /* A grant for every tx ring slot */
1304 if (gnttab_alloc_grant_references(TX_MAX_TARGET,
1305 &np->gref_tx_head) < 0) {
1306 pr_alert("can't alloc tx grant refs\n");
1307 err = -ENOMEM;
1308 goto exit_free_stats;
1309 }
1310 /* A grant for every rx ring slot */
1311 if (gnttab_alloc_grant_references(RX_MAX_TARGET,
1312 &np->gref_rx_head) < 0) {
1313 pr_alert("can't alloc rx grant refs\n");
1314 err = -ENOMEM;
1315 goto exit_free_tx;
1316 }
1317
1318 netdev->netdev_ops = &xennet_netdev_ops;
1319
1320 netif_napi_add(netdev, &np->napi, xennet_poll, 64);
1321 netdev->features = NETIF_F_IP_CSUM | NETIF_F_RXCSUM |
1322 NETIF_F_GSO_ROBUST;
1323 netdev->hw_features = NETIF_F_SG |
1324 NETIF_F_IPV6_CSUM |
1325 NETIF_F_TSO | NETIF_F_TSO6;
1326
1327 /*
1328 * Assume that all hw features are available for now. This set
1329 * will be adjusted by the call to netdev_update_features() in
1330 * xennet_connect() which is the earliest point where we can
1331 * negotiate with the backend regarding supported features.
1332 */
1333 netdev->features |= netdev->hw_features;
1334
1335 SET_ETHTOOL_OPS(netdev, &xennet_ethtool_ops);
1336 SET_NETDEV_DEV(netdev, &dev->dev);
1337
1338 netif_set_gso_max_size(netdev, XEN_NETIF_MAX_TX_SIZE - MAX_TCP_HEADER);
1339
1340 np->netdev = netdev;
1341
1342 netif_carrier_off(netdev);
1343
1344 return netdev;
1345
1346 exit_free_tx:
1347 gnttab_free_grant_references(np->gref_tx_head);
1348 exit_free_stats:
1349 free_percpu(np->stats);
1350 exit:
1351 free_netdev(netdev);
1352 return ERR_PTR(err);
1353}
1354
1355/**
1356 * Entry point to this code when a new device is created. Allocate the basic
1357 * structures and the ring buffers for communication with the backend, and
1358 * inform the backend of the appropriate details for those.
1359 */
1360static int netfront_probe(struct xenbus_device *dev,
1361 const struct xenbus_device_id *id)
1362{
1363 int err;
1364 struct net_device *netdev;
1365 struct netfront_info *info;
1366
1367 netdev = xennet_create_dev(dev);
1368 if (IS_ERR(netdev)) {
1369 err = PTR_ERR(netdev);
1370 xenbus_dev_fatal(dev, err, "creating netdev");
1371 return err;
1372 }
1373
1374 info = netdev_priv(netdev);
1375 dev_set_drvdata(&dev->dev, info);
1376
1377 err = register_netdev(info->netdev);
1378 if (err) {
1379 pr_warn("%s: register_netdev err=%d\n", __func__, err);
1380 goto fail;
1381 }
1382
1383 err = xennet_sysfs_addif(info->netdev);
1384 if (err) {
1385 unregister_netdev(info->netdev);
1386 pr_warn("%s: add sysfs failed err=%d\n", __func__, err);
1387 goto fail;
1388 }
1389
1390 return 0;
1391
1392 fail:
1393 free_netdev(netdev);
1394 dev_set_drvdata(&dev->dev, NULL);
1395 return err;
1396}
1397
1398static void xennet_end_access(int ref, void *page)
1399{
1400 /* This frees the page as a side-effect */
1401 if (ref != GRANT_INVALID_REF)
1402 gnttab_end_foreign_access(ref, 0, (unsigned long)page);
1403}
1404
1405static void xennet_disconnect_backend(struct netfront_info *info)
1406{
1407 /* Stop old i/f to prevent errors whilst we rebuild the state. */
1408 spin_lock_bh(&info->rx_lock);
1409 spin_lock_irq(&info->tx_lock);
1410 netif_carrier_off(info->netdev);
1411 spin_unlock_irq(&info->tx_lock);
1412 spin_unlock_bh(&info->rx_lock);
1413
1414 if (info->tx_irq && (info->tx_irq == info->rx_irq))
1415 unbind_from_irqhandler(info->tx_irq, info);
1416 if (info->tx_irq && (info->tx_irq != info->rx_irq)) {
1417 unbind_from_irqhandler(info->tx_irq, info);
1418 unbind_from_irqhandler(info->rx_irq, info);
1419 }
1420 info->tx_evtchn = info->rx_evtchn = 0;
1421 info->tx_irq = info->rx_irq = 0;
1422
1423 /* End access and free the pages */
1424 xennet_end_access(info->tx_ring_ref, info->tx.sring);
1425 xennet_end_access(info->rx_ring_ref, info->rx.sring);
1426
1427 info->tx_ring_ref = GRANT_INVALID_REF;
1428 info->rx_ring_ref = GRANT_INVALID_REF;
1429 info->tx.sring = NULL;
1430 info->rx.sring = NULL;
1431}
1432
1433/**
1434 * We are reconnecting to the backend, due to a suspend/resume, or a backend
1435 * driver restart. We tear down our netif structure and recreate it, but
1436 * leave the device-layer structures intact so that this is transparent to the
1437 * rest of the kernel.
1438 */
1439static int netfront_resume(struct xenbus_device *dev)
1440{
1441 struct netfront_info *info = dev_get_drvdata(&dev->dev);
1442
1443 dev_dbg(&dev->dev, "%s\n", dev->nodename);
1444
1445 xennet_disconnect_backend(info);
1446 return 0;
1447}
1448
1449static int xen_net_read_mac(struct xenbus_device *dev, u8 mac[])
1450{
1451 char *s, *e, *macstr;
1452 int i;
1453
1454 macstr = s = xenbus_read(XBT_NIL, dev->nodename, "mac", NULL);
1455 if (IS_ERR(macstr))
1456 return PTR_ERR(macstr);
1457
1458 for (i = 0; i < ETH_ALEN; i++) {
1459 mac[i] = simple_strtoul(s, &e, 16);
1460 if ((s == e) || (*e != ((i == ETH_ALEN-1) ? '\0' : ':'))) {
1461 kfree(macstr);
1462 return -ENOENT;
1463 }
1464 s = e+1;
1465 }
1466
1467 kfree(macstr);
1468 return 0;
1469}
1470
1471static int setup_netfront_single(struct netfront_info *info)
1472{
1473 int err;
1474
1475 err = xenbus_alloc_evtchn(info->xbdev, &info->tx_evtchn);
1476 if (err < 0)
1477 goto fail;
1478
1479 err = bind_evtchn_to_irqhandler(info->tx_evtchn,
1480 xennet_interrupt,
1481 0, info->netdev->name, info);
1482 if (err < 0)
1483 goto bind_fail;
1484 info->rx_evtchn = info->tx_evtchn;
1485 info->rx_irq = info->tx_irq = err;
1486
1487 return 0;
1488
1489bind_fail:
1490 xenbus_free_evtchn(info->xbdev, info->tx_evtchn);
1491 info->tx_evtchn = 0;
1492fail:
1493 return err;
1494}
1495
1496static int setup_netfront_split(struct netfront_info *info)
1497{
1498 int err;
1499
1500 err = xenbus_alloc_evtchn(info->xbdev, &info->tx_evtchn);
1501 if (err < 0)
1502 goto fail;
1503 err = xenbus_alloc_evtchn(info->xbdev, &info->rx_evtchn);
1504 if (err < 0)
1505 goto alloc_rx_evtchn_fail;
1506
1507 snprintf(info->tx_irq_name, sizeof(info->tx_irq_name),
1508 "%s-tx", info->netdev->name);
1509 err = bind_evtchn_to_irqhandler(info->tx_evtchn,
1510 xennet_tx_interrupt,
1511 0, info->tx_irq_name, info);
1512 if (err < 0)
1513 goto bind_tx_fail;
1514 info->tx_irq = err;
1515
1516 snprintf(info->rx_irq_name, sizeof(info->rx_irq_name),
1517 "%s-rx", info->netdev->name);
1518 err = bind_evtchn_to_irqhandler(info->rx_evtchn,
1519 xennet_rx_interrupt,
1520 0, info->rx_irq_name, info);
1521 if (err < 0)
1522 goto bind_rx_fail;
1523 info->rx_irq = err;
1524
1525 return 0;
1526
1527bind_rx_fail:
1528 unbind_from_irqhandler(info->tx_irq, info);
1529 info->tx_irq = 0;
1530bind_tx_fail:
1531 xenbus_free_evtchn(info->xbdev, info->rx_evtchn);
1532 info->rx_evtchn = 0;
1533alloc_rx_evtchn_fail:
1534 xenbus_free_evtchn(info->xbdev, info->tx_evtchn);
1535 info->tx_evtchn = 0;
1536fail:
1537 return err;
1538}
1539
1540static int setup_netfront(struct xenbus_device *dev, struct netfront_info *info)
1541{
1542 struct xen_netif_tx_sring *txs;
1543 struct xen_netif_rx_sring *rxs;
1544 int err;
1545 struct net_device *netdev = info->netdev;
1546 unsigned int feature_split_evtchn;
1547
1548 info->tx_ring_ref = GRANT_INVALID_REF;
1549 info->rx_ring_ref = GRANT_INVALID_REF;
1550 info->rx.sring = NULL;
1551 info->tx.sring = NULL;
1552 netdev->irq = 0;
1553
1554 err = xenbus_scanf(XBT_NIL, info->xbdev->otherend,
1555 "feature-split-event-channels", "%u",
1556 &feature_split_evtchn);
1557 if (err < 0)
1558 feature_split_evtchn = 0;
1559
1560 err = xen_net_read_mac(dev, netdev->dev_addr);
1561 if (err) {
1562 xenbus_dev_fatal(dev, err, "parsing %s/mac", dev->nodename);
1563 goto fail;
1564 }
1565
1566 txs = (struct xen_netif_tx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH);
1567 if (!txs) {
1568 err = -ENOMEM;
1569 xenbus_dev_fatal(dev, err, "allocating tx ring page");
1570 goto fail;
1571 }
1572 SHARED_RING_INIT(txs);
1573 FRONT_RING_INIT(&info->tx, txs, PAGE_SIZE);
1574
1575 err = xenbus_grant_ring(dev, virt_to_mfn(txs));
1576 if (err < 0)
1577 goto grant_tx_ring_fail;
1578
1579 info->tx_ring_ref = err;
1580 rxs = (struct xen_netif_rx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH);
1581 if (!rxs) {
1582 err = -ENOMEM;
1583 xenbus_dev_fatal(dev, err, "allocating rx ring page");
1584 goto alloc_rx_ring_fail;
1585 }
1586 SHARED_RING_INIT(rxs);
1587 FRONT_RING_INIT(&info->rx, rxs, PAGE_SIZE);
1588
1589 err = xenbus_grant_ring(dev, virt_to_mfn(rxs));
1590 if (err < 0)
1591 goto grant_rx_ring_fail;
1592 info->rx_ring_ref = err;
1593
1594 if (feature_split_evtchn)
1595 err = setup_netfront_split(info);
1596 /* setup single event channel if
1597 * a) feature-split-event-channels == 0
1598 * b) feature-split-event-channels == 1 but failed to setup
1599 */
1600 if (!feature_split_evtchn || (feature_split_evtchn && err))
1601 err = setup_netfront_single(info);
1602
1603 if (err)
1604 goto alloc_evtchn_fail;
1605
1606 return 0;
1607
1608 /* If we fail to setup netfront, it is safe to just revoke access to
1609 * granted pages because backend is not accessing it at this point.
1610 */
1611alloc_evtchn_fail:
1612 gnttab_end_foreign_access_ref(info->rx_ring_ref, 0);
1613grant_rx_ring_fail:
1614 free_page((unsigned long)rxs);
1615alloc_rx_ring_fail:
1616 gnttab_end_foreign_access_ref(info->tx_ring_ref, 0);
1617grant_tx_ring_fail:
1618 free_page((unsigned long)txs);
1619fail:
1620 return err;
1621}
1622
1623/* Common code used when first setting up, and when resuming. */
1624static int talk_to_netback(struct xenbus_device *dev,
1625 struct netfront_info *info)
1626{
1627 const char *message;
1628 struct xenbus_transaction xbt;
1629 int err;
1630
1631 /* Create shared ring, alloc event channel. */
1632 err = setup_netfront(dev, info);
1633 if (err)
1634 goto out;
1635
1636again:
1637 err = xenbus_transaction_start(&xbt);
1638 if (err) {
1639 xenbus_dev_fatal(dev, err, "starting transaction");
1640 goto destroy_ring;
1641 }
1642
1643 err = xenbus_printf(xbt, dev->nodename, "tx-ring-ref", "%u",
1644 info->tx_ring_ref);
1645 if (err) {
1646 message = "writing tx ring-ref";
1647 goto abort_transaction;
1648 }
1649 err = xenbus_printf(xbt, dev->nodename, "rx-ring-ref", "%u",
1650 info->rx_ring_ref);
1651 if (err) {
1652 message = "writing rx ring-ref";
1653 goto abort_transaction;
1654 }
1655
1656 if (info->tx_evtchn == info->rx_evtchn) {
1657 err = xenbus_printf(xbt, dev->nodename,
1658 "event-channel", "%u", info->tx_evtchn);
1659 if (err) {
1660 message = "writing event-channel";
1661 goto abort_transaction;
1662 }
1663 } else {
1664 err = xenbus_printf(xbt, dev->nodename,
1665 "event-channel-tx", "%u", info->tx_evtchn);
1666 if (err) {
1667 message = "writing event-channel-tx";
1668 goto abort_transaction;
1669 }
1670 err = xenbus_printf(xbt, dev->nodename,
1671 "event-channel-rx", "%u", info->rx_evtchn);
1672 if (err) {
1673 message = "writing event-channel-rx";
1674 goto abort_transaction;
1675 }
1676 }
1677
1678 err = xenbus_printf(xbt, dev->nodename, "request-rx-copy", "%u",
1679 1);
1680 if (err) {
1681 message = "writing request-rx-copy";
1682 goto abort_transaction;
1683 }
1684
1685 err = xenbus_printf(xbt, dev->nodename, "feature-rx-notify", "%d", 1);
1686 if (err) {
1687 message = "writing feature-rx-notify";
1688 goto abort_transaction;
1689 }
1690
1691 err = xenbus_printf(xbt, dev->nodename, "feature-sg", "%d", 1);
1692 if (err) {
1693 message = "writing feature-sg";
1694 goto abort_transaction;
1695 }
1696
1697 err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv4", "%d", 1);
1698 if (err) {
1699 message = "writing feature-gso-tcpv4";
1700 goto abort_transaction;
1701 }
1702
1703 err = xenbus_write(xbt, dev->nodename, "feature-gso-tcpv6", "1");
1704 if (err) {
1705 message = "writing feature-gso-tcpv6";
1706 goto abort_transaction;
1707 }
1708
1709 err = xenbus_write(xbt, dev->nodename, "feature-ipv6-csum-offload",
1710 "1");
1711 if (err) {
1712 message = "writing feature-ipv6-csum-offload";
1713 goto abort_transaction;
1714 }
1715
1716 err = xenbus_transaction_end(xbt, 0);
1717 if (err) {
1718 if (err == -EAGAIN)
1719 goto again;
1720 xenbus_dev_fatal(dev, err, "completing transaction");
1721 goto destroy_ring;
1722 }
1723
1724 return 0;
1725
1726 abort_transaction:
1727 xenbus_transaction_end(xbt, 1);
1728 xenbus_dev_fatal(dev, err, "%s", message);
1729 destroy_ring:
1730 xennet_disconnect_backend(info);
1731 out:
1732 return err;
1733}
1734
1735static int xennet_connect(struct net_device *dev)
1736{
1737 struct netfront_info *np = netdev_priv(dev);
1738 int i, requeue_idx, err;
1739 struct sk_buff *skb;
1740 grant_ref_t ref;
1741 struct xen_netif_rx_request *req;
1742 unsigned int feature_rx_copy;
1743
1744 err = xenbus_scanf(XBT_NIL, np->xbdev->otherend,
1745 "feature-rx-copy", "%u", &feature_rx_copy);
1746 if (err != 1)
1747 feature_rx_copy = 0;
1748
1749 if (!feature_rx_copy) {
1750 dev_info(&dev->dev,
1751 "backend does not support copying receive path\n");
1752 return -ENODEV;
1753 }
1754
1755 err = talk_to_netback(np->xbdev, np);
1756 if (err)
1757 return err;
1758
1759 rtnl_lock();
1760 netdev_update_features(dev);
1761 rtnl_unlock();
1762
1763 spin_lock_bh(&np->rx_lock);
1764 spin_lock_irq(&np->tx_lock);
1765
1766 /* Step 1: Discard all pending TX packet fragments. */
1767 xennet_release_tx_bufs(np);
1768
1769 /* Step 2: Rebuild the RX buffer freelist and the RX ring itself. */
1770 for (requeue_idx = 0, i = 0; i < NET_RX_RING_SIZE; i++) {
1771 skb_frag_t *frag;
1772 const struct page *page;
1773 if (!np->rx_skbs[i])
1774 continue;
1775
1776 skb = np->rx_skbs[requeue_idx] = xennet_get_rx_skb(np, i);
1777 ref = np->grant_rx_ref[requeue_idx] = xennet_get_rx_ref(np, i);
1778 req = RING_GET_REQUEST(&np->rx, requeue_idx);
1779
1780 frag = &skb_shinfo(skb)->frags[0];
1781 page = skb_frag_page(frag);
1782 gnttab_grant_foreign_access_ref(
1783 ref, np->xbdev->otherend_id,
1784 pfn_to_mfn(page_to_pfn(page)),
1785 0);
1786 req->gref = ref;
1787 req->id = requeue_idx;
1788
1789 requeue_idx++;
1790 }
1791
1792 np->rx.req_prod_pvt = requeue_idx;
1793
1794 /*
1795 * Step 3: All public and private state should now be sane. Get
1796 * ready to start sending and receiving packets and give the driver
1797 * domain a kick because we've probably just requeued some
1798 * packets.
1799 */
1800 netif_carrier_on(np->netdev);
1801 notify_remote_via_irq(np->tx_irq);
1802 if (np->tx_irq != np->rx_irq)
1803 notify_remote_via_irq(np->rx_irq);
1804 xennet_tx_buf_gc(dev);
1805 xennet_alloc_rx_buffers(dev);
1806
1807 spin_unlock_irq(&np->tx_lock);
1808 spin_unlock_bh(&np->rx_lock);
1809
1810 return 0;
1811}
1812
1813/**
1814 * Callback received when the backend's state changes.
1815 */
1816static void netback_changed(struct xenbus_device *dev,
1817 enum xenbus_state backend_state)
1818{
1819 struct netfront_info *np = dev_get_drvdata(&dev->dev);
1820 struct net_device *netdev = np->netdev;
1821
1822 dev_dbg(&dev->dev, "%s\n", xenbus_strstate(backend_state));
1823
1824 switch (backend_state) {
1825 case XenbusStateInitialising:
1826 case XenbusStateInitialised:
1827 case XenbusStateReconfiguring:
1828 case XenbusStateReconfigured:
1829 case XenbusStateUnknown:
1830 break;
1831
1832 case XenbusStateInitWait:
1833 if (dev->state != XenbusStateInitialising)
1834 break;
1835 if (xennet_connect(netdev) != 0)
1836 break;
1837 xenbus_switch_state(dev, XenbusStateConnected);
1838 break;
1839
1840 case XenbusStateConnected:
1841 netdev_notify_peers(netdev);
1842 break;
1843
1844 case XenbusStateClosed:
1845 if (dev->state == XenbusStateClosed)
1846 break;
1847 /* Missed the backend's CLOSING state -- fallthrough */
1848 case XenbusStateClosing:
1849 xenbus_frontend_closed(dev);
1850 break;
1851 }
1852}
1853
1854static const struct xennet_stat {
1855 char name[ETH_GSTRING_LEN];
1856 u16 offset;
1857} xennet_stats[] = {
1858 {
1859 "rx_gso_checksum_fixup",
1860 offsetof(struct netfront_info, rx_gso_checksum_fixup)
1861 },
1862};
1863
1864static int xennet_get_sset_count(struct net_device *dev, int string_set)
1865{
1866 switch (string_set) {
1867 case ETH_SS_STATS:
1868 return ARRAY_SIZE(xennet_stats);
1869 default:
1870 return -EINVAL;
1871 }
1872}
1873
1874static void xennet_get_ethtool_stats(struct net_device *dev,
1875 struct ethtool_stats *stats, u64 * data)
1876{
1877 void *np = netdev_priv(dev);
1878 int i;
1879
1880 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++)
1881 data[i] = *(unsigned long *)(np + xennet_stats[i].offset);
1882}
1883
1884static void xennet_get_strings(struct net_device *dev, u32 stringset, u8 * data)
1885{
1886 int i;
1887
1888 switch (stringset) {
1889 case ETH_SS_STATS:
1890 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++)
1891 memcpy(data + i * ETH_GSTRING_LEN,
1892 xennet_stats[i].name, ETH_GSTRING_LEN);
1893 break;
1894 }
1895}
1896
1897static const struct ethtool_ops xennet_ethtool_ops =
1898{
1899 .get_link = ethtool_op_get_link,
1900
1901 .get_sset_count = xennet_get_sset_count,
1902 .get_ethtool_stats = xennet_get_ethtool_stats,
1903 .get_strings = xennet_get_strings,
1904};
1905
1906#ifdef CONFIG_SYSFS
1907static ssize_t show_rxbuf_min(struct device *dev,
1908 struct device_attribute *attr, char *buf)
1909{
1910 struct net_device *netdev = to_net_dev(dev);
1911 struct netfront_info *info = netdev_priv(netdev);
1912
1913 return sprintf(buf, "%u\n", info->rx_min_target);
1914}
1915
1916static ssize_t store_rxbuf_min(struct device *dev,
1917 struct device_attribute *attr,
1918 const char *buf, size_t len)
1919{
1920 struct net_device *netdev = to_net_dev(dev);
1921 struct netfront_info *np = netdev_priv(netdev);
1922 char *endp;
1923 unsigned long target;
1924
1925 if (!capable(CAP_NET_ADMIN))
1926 return -EPERM;
1927
1928 target = simple_strtoul(buf, &endp, 0);
1929 if (endp == buf)
1930 return -EBADMSG;
1931
1932 if (target < RX_MIN_TARGET)
1933 target = RX_MIN_TARGET;
1934 if (target > RX_MAX_TARGET)
1935 target = RX_MAX_TARGET;
1936
1937 spin_lock_bh(&np->rx_lock);
1938 if (target > np->rx_max_target)
1939 np->rx_max_target = target;
1940 np->rx_min_target = target;
1941 if (target > np->rx_target)
1942 np->rx_target = target;
1943
1944 xennet_alloc_rx_buffers(netdev);
1945
1946 spin_unlock_bh(&np->rx_lock);
1947 return len;
1948}
1949
1950static ssize_t show_rxbuf_max(struct device *dev,
1951 struct device_attribute *attr, char *buf)
1952{
1953 struct net_device *netdev = to_net_dev(dev);
1954 struct netfront_info *info = netdev_priv(netdev);
1955
1956 return sprintf(buf, "%u\n", info->rx_max_target);
1957}
1958
1959static ssize_t store_rxbuf_max(struct device *dev,
1960 struct device_attribute *attr,
1961 const char *buf, size_t len)
1962{
1963 struct net_device *netdev = to_net_dev(dev);
1964 struct netfront_info *np = netdev_priv(netdev);
1965 char *endp;
1966 unsigned long target;
1967
1968 if (!capable(CAP_NET_ADMIN))
1969 return -EPERM;
1970
1971 target = simple_strtoul(buf, &endp, 0);
1972 if (endp == buf)
1973 return -EBADMSG;
1974
1975 if (target < RX_MIN_TARGET)
1976 target = RX_MIN_TARGET;
1977 if (target > RX_MAX_TARGET)
1978 target = RX_MAX_TARGET;
1979
1980 spin_lock_bh(&np->rx_lock);
1981 if (target < np->rx_min_target)
1982 np->rx_min_target = target;
1983 np->rx_max_target = target;
1984 if (target < np->rx_target)
1985 np->rx_target = target;
1986
1987 xennet_alloc_rx_buffers(netdev);
1988
1989 spin_unlock_bh(&np->rx_lock);
1990 return len;
1991}
1992
1993static ssize_t show_rxbuf_cur(struct device *dev,
1994 struct device_attribute *attr, char *buf)
1995{
1996 struct net_device *netdev = to_net_dev(dev);
1997 struct netfront_info *info = netdev_priv(netdev);
1998
1999 return sprintf(buf, "%u\n", info->rx_target);
2000}
2001
2002static struct device_attribute xennet_attrs[] = {
2003 __ATTR(rxbuf_min, S_IRUGO|S_IWUSR, show_rxbuf_min, store_rxbuf_min),
2004 __ATTR(rxbuf_max, S_IRUGO|S_IWUSR, show_rxbuf_max, store_rxbuf_max),
2005 __ATTR(rxbuf_cur, S_IRUGO, show_rxbuf_cur, NULL),
2006};
2007
2008static int xennet_sysfs_addif(struct net_device *netdev)
2009{
2010 int i;
2011 int err;
2012
2013 for (i = 0; i < ARRAY_SIZE(xennet_attrs); i++) {
2014 err = device_create_file(&netdev->dev,
2015 &xennet_attrs[i]);
2016 if (err)
2017 goto fail;
2018 }
2019 return 0;
2020
2021 fail:
2022 while (--i >= 0)
2023 device_remove_file(&netdev->dev, &xennet_attrs[i]);
2024 return err;
2025}
2026
2027static void xennet_sysfs_delif(struct net_device *netdev)
2028{
2029 int i;
2030
2031 for (i = 0; i < ARRAY_SIZE(xennet_attrs); i++)
2032 device_remove_file(&netdev->dev, &xennet_attrs[i]);
2033}
2034
2035#endif /* CONFIG_SYSFS */
2036
2037static const struct xenbus_device_id netfront_ids[] = {
2038 { "vif" },
2039 { "" }
2040};
2041
2042
2043static int xennet_remove(struct xenbus_device *dev)
2044{
2045 struct netfront_info *info = dev_get_drvdata(&dev->dev);
2046
2047 dev_dbg(&dev->dev, "%s\n", dev->nodename);
2048
2049 xennet_disconnect_backend(info);
2050
2051 xennet_sysfs_delif(info->netdev);
2052
2053 unregister_netdev(info->netdev);
2054
2055 del_timer_sync(&info->rx_refill_timer);
2056
2057 free_percpu(info->stats);
2058
2059 free_netdev(info->netdev);
2060
2061 return 0;
2062}
2063
2064static DEFINE_XENBUS_DRIVER(netfront, ,
2065 .probe = netfront_probe,
2066 .remove = xennet_remove,
2067 .resume = netfront_resume,
2068 .otherend_changed = netback_changed,
2069);
2070
2071static int __init netif_init(void)
2072{
2073 if (!xen_domain())
2074 return -ENODEV;
2075
2076 if (!xen_has_pv_nic_devices())
2077 return -ENODEV;
2078
2079 pr_info("Initialising Xen virtual ethernet driver\n");
2080
2081 return xenbus_register_frontend(&netfront_driver);
2082}
2083module_init(netif_init);
2084
2085
2086static void __exit netif_exit(void)
2087{
2088 xenbus_unregister_driver(&netfront_driver);
2089}
2090module_exit(netif_exit);
2091
2092MODULE_DESCRIPTION("Xen virtual network device frontend");
2093MODULE_LICENSE("GPL");
2094MODULE_ALIAS("xen:vif");
2095MODULE_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 = 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");