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1/*
2 * Virtual network driver for conversing with remote driver backends.
3 *
4 * Copyright (c) 2002-2005, K A Fraser
5 * Copyright (c) 2005, XenSource Ltd
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License version 2
9 * as published by the Free Software Foundation; or, when distributed
10 * separately from the Linux kernel or incorporated into other
11 * software packages, subject to the following license:
12 *
13 * Permission is hereby granted, free of charge, to any person obtaining a copy
14 * of this source file (the "Software"), to deal in the Software without
15 * restriction, including without limitation the rights to use, copy, modify,
16 * merge, publish, distribute, sublicense, and/or sell copies of the Software,
17 * and to permit persons to whom the Software is furnished to do so, subject to
18 * the following conditions:
19 *
20 * The above copyright notice and this permission notice shall be included in
21 * all copies or substantial portions of the Software.
22 *
23 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
24 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
25 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
26 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
27 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
28 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
29 * IN THE SOFTWARE.
30 */
31
32#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
33
34#include <linux/module.h>
35#include <linux/kernel.h>
36#include <linux/netdevice.h>
37#include <linux/etherdevice.h>
38#include <linux/skbuff.h>
39#include <linux/ethtool.h>
40#include <linux/if_ether.h>
41#include <net/tcp.h>
42#include <linux/udp.h>
43#include <linux/moduleparam.h>
44#include <linux/mm.h>
45#include <linux/slab.h>
46#include <net/ip.h>
47#include <linux/bpf.h>
48#include <net/page_pool/types.h>
49#include <linux/bpf_trace.h>
50
51#include <xen/xen.h>
52#include <xen/xenbus.h>
53#include <xen/events.h>
54#include <xen/page.h>
55#include <xen/platform_pci.h>
56#include <xen/grant_table.h>
57
58#include <xen/interface/io/netif.h>
59#include <xen/interface/memory.h>
60#include <xen/interface/grant_table.h>
61
62/* Module parameters */
63#define MAX_QUEUES_DEFAULT 8
64static unsigned int xennet_max_queues;
65module_param_named(max_queues, xennet_max_queues, uint, 0644);
66MODULE_PARM_DESC(max_queues,
67 "Maximum number of queues per virtual interface");
68
69static bool __read_mostly xennet_trusted = true;
70module_param_named(trusted, xennet_trusted, bool, 0644);
71MODULE_PARM_DESC(trusted, "Is the backend trusted");
72
73#define XENNET_TIMEOUT (5 * HZ)
74
75static const struct ethtool_ops xennet_ethtool_ops;
76
77struct netfront_cb {
78 int pull_to;
79};
80
81#define NETFRONT_SKB_CB(skb) ((struct netfront_cb *)((skb)->cb))
82
83#define RX_COPY_THRESHOLD 256
84
85#define NET_TX_RING_SIZE __CONST_RING_SIZE(xen_netif_tx, XEN_PAGE_SIZE)
86#define NET_RX_RING_SIZE __CONST_RING_SIZE(xen_netif_rx, XEN_PAGE_SIZE)
87
88/* Minimum number of Rx slots (includes slot for GSO metadata). */
89#define NET_RX_SLOTS_MIN (XEN_NETIF_NR_SLOTS_MIN + 1)
90
91/* Queue name is interface name with "-qNNN" appended */
92#define QUEUE_NAME_SIZE (IFNAMSIZ + 6)
93
94/* IRQ name is queue name with "-tx" or "-rx" appended */
95#define IRQ_NAME_SIZE (QUEUE_NAME_SIZE + 3)
96
97static DECLARE_WAIT_QUEUE_HEAD(module_wq);
98
99struct netfront_stats {
100 u64 packets;
101 u64 bytes;
102 struct u64_stats_sync syncp;
103};
104
105struct netfront_info;
106
107struct netfront_queue {
108 unsigned int id; /* Queue ID, 0-based */
109 char name[QUEUE_NAME_SIZE]; /* DEVNAME-qN */
110 struct netfront_info *info;
111
112 struct bpf_prog __rcu *xdp_prog;
113
114 struct napi_struct napi;
115
116 /* Split event channels support, tx_* == rx_* when using
117 * single event channel.
118 */
119 unsigned int tx_evtchn, rx_evtchn;
120 unsigned int tx_irq, rx_irq;
121 /* Only used when split event channels support is enabled */
122 char tx_irq_name[IRQ_NAME_SIZE]; /* DEVNAME-qN-tx */
123 char rx_irq_name[IRQ_NAME_SIZE]; /* DEVNAME-qN-rx */
124
125 spinlock_t tx_lock;
126 struct xen_netif_tx_front_ring tx;
127 int tx_ring_ref;
128
129 /*
130 * {tx,rx}_skbs store outstanding skbuffs. Free tx_skb entries
131 * are linked from tx_skb_freelist through tx_link.
132 */
133 struct sk_buff *tx_skbs[NET_TX_RING_SIZE];
134 unsigned short tx_link[NET_TX_RING_SIZE];
135#define TX_LINK_NONE 0xffff
136#define TX_PENDING 0xfffe
137 grant_ref_t gref_tx_head;
138 grant_ref_t grant_tx_ref[NET_TX_RING_SIZE];
139 struct page *grant_tx_page[NET_TX_RING_SIZE];
140 unsigned tx_skb_freelist;
141 unsigned int tx_pend_queue;
142
143 spinlock_t rx_lock ____cacheline_aligned_in_smp;
144 struct xen_netif_rx_front_ring rx;
145 int rx_ring_ref;
146
147 struct timer_list rx_refill_timer;
148
149 struct sk_buff *rx_skbs[NET_RX_RING_SIZE];
150 grant_ref_t gref_rx_head;
151 grant_ref_t grant_rx_ref[NET_RX_RING_SIZE];
152
153 unsigned int rx_rsp_unconsumed;
154 spinlock_t rx_cons_lock;
155
156 struct page_pool *page_pool;
157 struct xdp_rxq_info xdp_rxq;
158};
159
160struct netfront_info {
161 struct list_head list;
162 struct net_device *netdev;
163
164 struct xenbus_device *xbdev;
165
166 /* Multi-queue support */
167 struct netfront_queue *queues;
168
169 /* Statistics */
170 struct netfront_stats __percpu *rx_stats;
171 struct netfront_stats __percpu *tx_stats;
172
173 /* XDP state */
174 bool netback_has_xdp_headroom;
175 bool netfront_xdp_enabled;
176
177 /* Is device behaving sane? */
178 bool broken;
179
180 /* Should skbs be bounced into a zeroed buffer? */
181 bool bounce;
182
183 atomic_t rx_gso_checksum_fixup;
184};
185
186struct netfront_rx_info {
187 struct xen_netif_rx_response rx;
188 struct xen_netif_extra_info extras[XEN_NETIF_EXTRA_TYPE_MAX - 1];
189};
190
191/*
192 * Access macros for acquiring freeing slots in tx_skbs[].
193 */
194
195static void add_id_to_list(unsigned *head, unsigned short *list,
196 unsigned short id)
197{
198 list[id] = *head;
199 *head = id;
200}
201
202static unsigned short get_id_from_list(unsigned *head, unsigned short *list)
203{
204 unsigned int id = *head;
205
206 if (id != TX_LINK_NONE) {
207 *head = list[id];
208 list[id] = TX_LINK_NONE;
209 }
210 return id;
211}
212
213static int xennet_rxidx(RING_IDX idx)
214{
215 return idx & (NET_RX_RING_SIZE - 1);
216}
217
218static struct sk_buff *xennet_get_rx_skb(struct netfront_queue *queue,
219 RING_IDX ri)
220{
221 int i = xennet_rxidx(ri);
222 struct sk_buff *skb = queue->rx_skbs[i];
223 queue->rx_skbs[i] = NULL;
224 return skb;
225}
226
227static grant_ref_t xennet_get_rx_ref(struct netfront_queue *queue,
228 RING_IDX ri)
229{
230 int i = xennet_rxidx(ri);
231 grant_ref_t ref = queue->grant_rx_ref[i];
232 queue->grant_rx_ref[i] = INVALID_GRANT_REF;
233 return ref;
234}
235
236#ifdef CONFIG_SYSFS
237static const struct attribute_group xennet_dev_group;
238#endif
239
240static bool xennet_can_sg(struct net_device *dev)
241{
242 return dev->features & NETIF_F_SG;
243}
244
245
246static void rx_refill_timeout(struct timer_list *t)
247{
248 struct netfront_queue *queue = from_timer(queue, t, rx_refill_timer);
249 napi_schedule(&queue->napi);
250}
251
252static int netfront_tx_slot_available(struct netfront_queue *queue)
253{
254 return (queue->tx.req_prod_pvt - queue->tx.rsp_cons) <
255 (NET_TX_RING_SIZE - XEN_NETIF_NR_SLOTS_MIN - 1);
256}
257
258static void xennet_maybe_wake_tx(struct netfront_queue *queue)
259{
260 struct net_device *dev = queue->info->netdev;
261 struct netdev_queue *dev_queue = netdev_get_tx_queue(dev, queue->id);
262
263 if (unlikely(netif_tx_queue_stopped(dev_queue)) &&
264 netfront_tx_slot_available(queue) &&
265 likely(netif_running(dev)))
266 netif_tx_wake_queue(netdev_get_tx_queue(dev, queue->id));
267}
268
269
270static struct sk_buff *xennet_alloc_one_rx_buffer(struct netfront_queue *queue)
271{
272 struct sk_buff *skb;
273 struct page *page;
274
275 skb = __netdev_alloc_skb(queue->info->netdev,
276 RX_COPY_THRESHOLD + NET_IP_ALIGN,
277 GFP_ATOMIC | __GFP_NOWARN);
278 if (unlikely(!skb))
279 return NULL;
280
281 page = page_pool_alloc_pages(queue->page_pool,
282 GFP_ATOMIC | __GFP_NOWARN | __GFP_ZERO);
283 if (unlikely(!page)) {
284 kfree_skb(skb);
285 return NULL;
286 }
287 skb_add_rx_frag(skb, 0, page, 0, 0, PAGE_SIZE);
288
289 /* Align ip header to a 16 bytes boundary */
290 skb_reserve(skb, NET_IP_ALIGN);
291 skb->dev = queue->info->netdev;
292
293 return skb;
294}
295
296
297static void xennet_alloc_rx_buffers(struct netfront_queue *queue)
298{
299 RING_IDX req_prod = queue->rx.req_prod_pvt;
300 int notify;
301 int err = 0;
302
303 if (unlikely(!netif_carrier_ok(queue->info->netdev)))
304 return;
305
306 for (req_prod = queue->rx.req_prod_pvt;
307 req_prod - queue->rx.rsp_cons < NET_RX_RING_SIZE;
308 req_prod++) {
309 struct sk_buff *skb;
310 unsigned short id;
311 grant_ref_t ref;
312 struct page *page;
313 struct xen_netif_rx_request *req;
314
315 skb = xennet_alloc_one_rx_buffer(queue);
316 if (!skb) {
317 err = -ENOMEM;
318 break;
319 }
320
321 id = xennet_rxidx(req_prod);
322
323 BUG_ON(queue->rx_skbs[id]);
324 queue->rx_skbs[id] = skb;
325
326 ref = gnttab_claim_grant_reference(&queue->gref_rx_head);
327 WARN_ON_ONCE(IS_ERR_VALUE((unsigned long)(int)ref));
328 queue->grant_rx_ref[id] = ref;
329
330 page = skb_frag_page(&skb_shinfo(skb)->frags[0]);
331
332 req = RING_GET_REQUEST(&queue->rx, req_prod);
333 gnttab_page_grant_foreign_access_ref_one(ref,
334 queue->info->xbdev->otherend_id,
335 page,
336 0);
337 req->id = id;
338 req->gref = ref;
339 }
340
341 queue->rx.req_prod_pvt = req_prod;
342
343 /* Try again later if there are not enough requests or skb allocation
344 * failed.
345 * Enough requests is quantified as the sum of newly created slots and
346 * the unconsumed slots at the backend.
347 */
348 if (req_prod - queue->rx.rsp_cons < NET_RX_SLOTS_MIN ||
349 unlikely(err)) {
350 mod_timer(&queue->rx_refill_timer, jiffies + (HZ/10));
351 return;
352 }
353
354 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->rx, notify);
355 if (notify)
356 notify_remote_via_irq(queue->rx_irq);
357}
358
359static int xennet_open(struct net_device *dev)
360{
361 struct netfront_info *np = netdev_priv(dev);
362 unsigned int num_queues = dev->real_num_tx_queues;
363 unsigned int i = 0;
364 struct netfront_queue *queue = NULL;
365
366 if (!np->queues || np->broken)
367 return -ENODEV;
368
369 for (i = 0; i < num_queues; ++i) {
370 queue = &np->queues[i];
371 napi_enable(&queue->napi);
372
373 spin_lock_bh(&queue->rx_lock);
374 if (netif_carrier_ok(dev)) {
375 xennet_alloc_rx_buffers(queue);
376 queue->rx.sring->rsp_event = queue->rx.rsp_cons + 1;
377 if (RING_HAS_UNCONSUMED_RESPONSES(&queue->rx))
378 napi_schedule(&queue->napi);
379 }
380 spin_unlock_bh(&queue->rx_lock);
381 }
382
383 netif_tx_start_all_queues(dev);
384
385 return 0;
386}
387
388static bool xennet_tx_buf_gc(struct netfront_queue *queue)
389{
390 RING_IDX cons, prod;
391 unsigned short id;
392 struct sk_buff *skb;
393 bool more_to_do;
394 bool work_done = false;
395 const struct device *dev = &queue->info->netdev->dev;
396
397 BUG_ON(!netif_carrier_ok(queue->info->netdev));
398
399 do {
400 prod = queue->tx.sring->rsp_prod;
401 if (RING_RESPONSE_PROD_OVERFLOW(&queue->tx, prod)) {
402 dev_alert(dev, "Illegal number of responses %u\n",
403 prod - queue->tx.rsp_cons);
404 goto err;
405 }
406 rmb(); /* Ensure we see responses up to 'rp'. */
407
408 for (cons = queue->tx.rsp_cons; cons != prod; cons++) {
409 struct xen_netif_tx_response txrsp;
410
411 work_done = true;
412
413 RING_COPY_RESPONSE(&queue->tx, cons, &txrsp);
414 if (txrsp.status == XEN_NETIF_RSP_NULL)
415 continue;
416
417 id = txrsp.id;
418 if (id >= RING_SIZE(&queue->tx)) {
419 dev_alert(dev,
420 "Response has incorrect id (%u)\n",
421 id);
422 goto err;
423 }
424 if (queue->tx_link[id] != TX_PENDING) {
425 dev_alert(dev,
426 "Response for inactive request\n");
427 goto err;
428 }
429
430 queue->tx_link[id] = TX_LINK_NONE;
431 skb = queue->tx_skbs[id];
432 queue->tx_skbs[id] = NULL;
433 if (unlikely(!gnttab_end_foreign_access_ref(
434 queue->grant_tx_ref[id]))) {
435 dev_alert(dev,
436 "Grant still in use by backend domain\n");
437 goto err;
438 }
439 gnttab_release_grant_reference(
440 &queue->gref_tx_head, queue->grant_tx_ref[id]);
441 queue->grant_tx_ref[id] = INVALID_GRANT_REF;
442 queue->grant_tx_page[id] = NULL;
443 add_id_to_list(&queue->tx_skb_freelist, queue->tx_link, id);
444 dev_kfree_skb_irq(skb);
445 }
446
447 queue->tx.rsp_cons = prod;
448
449 RING_FINAL_CHECK_FOR_RESPONSES(&queue->tx, more_to_do);
450 } while (more_to_do);
451
452 xennet_maybe_wake_tx(queue);
453
454 return work_done;
455
456 err:
457 queue->info->broken = true;
458 dev_alert(dev, "Disabled for further use\n");
459
460 return work_done;
461}
462
463struct xennet_gnttab_make_txreq {
464 struct netfront_queue *queue;
465 struct sk_buff *skb;
466 struct page *page;
467 struct xen_netif_tx_request *tx; /* Last request on ring page */
468 struct xen_netif_tx_request tx_local; /* Last request local copy*/
469 unsigned int size;
470};
471
472static void xennet_tx_setup_grant(unsigned long gfn, unsigned int offset,
473 unsigned int len, void *data)
474{
475 struct xennet_gnttab_make_txreq *info = data;
476 unsigned int id;
477 struct xen_netif_tx_request *tx;
478 grant_ref_t ref;
479 /* convenient aliases */
480 struct page *page = info->page;
481 struct netfront_queue *queue = info->queue;
482 struct sk_buff *skb = info->skb;
483
484 id = get_id_from_list(&queue->tx_skb_freelist, queue->tx_link);
485 tx = RING_GET_REQUEST(&queue->tx, queue->tx.req_prod_pvt++);
486 ref = gnttab_claim_grant_reference(&queue->gref_tx_head);
487 WARN_ON_ONCE(IS_ERR_VALUE((unsigned long)(int)ref));
488
489 gnttab_grant_foreign_access_ref(ref, queue->info->xbdev->otherend_id,
490 gfn, GNTMAP_readonly);
491
492 queue->tx_skbs[id] = skb;
493 queue->grant_tx_page[id] = page;
494 queue->grant_tx_ref[id] = ref;
495
496 info->tx_local.id = id;
497 info->tx_local.gref = ref;
498 info->tx_local.offset = offset;
499 info->tx_local.size = len;
500 info->tx_local.flags = 0;
501
502 *tx = info->tx_local;
503
504 /*
505 * Put the request in the pending queue, it will be set to be pending
506 * when the producer index is about to be raised.
507 */
508 add_id_to_list(&queue->tx_pend_queue, queue->tx_link, id);
509
510 info->tx = tx;
511 info->size += info->tx_local.size;
512}
513
514static struct xen_netif_tx_request *xennet_make_first_txreq(
515 struct xennet_gnttab_make_txreq *info,
516 unsigned int offset, unsigned int len)
517{
518 info->size = 0;
519
520 gnttab_for_one_grant(info->page, offset, len, xennet_tx_setup_grant, info);
521
522 return info->tx;
523}
524
525static void xennet_make_one_txreq(unsigned long gfn, unsigned int offset,
526 unsigned int len, void *data)
527{
528 struct xennet_gnttab_make_txreq *info = data;
529
530 info->tx->flags |= XEN_NETTXF_more_data;
531 skb_get(info->skb);
532 xennet_tx_setup_grant(gfn, offset, len, data);
533}
534
535static void xennet_make_txreqs(
536 struct xennet_gnttab_make_txreq *info,
537 struct page *page,
538 unsigned int offset, unsigned int len)
539{
540 /* Skip unused frames from start of page */
541 page += offset >> PAGE_SHIFT;
542 offset &= ~PAGE_MASK;
543
544 while (len) {
545 info->page = page;
546 info->size = 0;
547
548 gnttab_foreach_grant_in_range(page, offset, len,
549 xennet_make_one_txreq,
550 info);
551
552 page++;
553 offset = 0;
554 len -= info->size;
555 }
556}
557
558/*
559 * Count how many ring slots are required to send this skb. Each frag
560 * might be a compound page.
561 */
562static int xennet_count_skb_slots(struct sk_buff *skb)
563{
564 int i, frags = skb_shinfo(skb)->nr_frags;
565 int slots;
566
567 slots = gnttab_count_grant(offset_in_page(skb->data),
568 skb_headlen(skb));
569
570 for (i = 0; i < frags; i++) {
571 skb_frag_t *frag = skb_shinfo(skb)->frags + i;
572 unsigned long size = skb_frag_size(frag);
573 unsigned long offset = skb_frag_off(frag);
574
575 /* Skip unused frames from start of page */
576 offset &= ~PAGE_MASK;
577
578 slots += gnttab_count_grant(offset, size);
579 }
580
581 return slots;
582}
583
584static u16 xennet_select_queue(struct net_device *dev, struct sk_buff *skb,
585 struct net_device *sb_dev)
586{
587 unsigned int num_queues = dev->real_num_tx_queues;
588 u32 hash;
589 u16 queue_idx;
590
591 /* First, check if there is only one queue */
592 if (num_queues == 1) {
593 queue_idx = 0;
594 } else {
595 hash = skb_get_hash(skb);
596 queue_idx = hash % num_queues;
597 }
598
599 return queue_idx;
600}
601
602static void xennet_mark_tx_pending(struct netfront_queue *queue)
603{
604 unsigned int i;
605
606 while ((i = get_id_from_list(&queue->tx_pend_queue, queue->tx_link)) !=
607 TX_LINK_NONE)
608 queue->tx_link[i] = TX_PENDING;
609}
610
611static int xennet_xdp_xmit_one(struct net_device *dev,
612 struct netfront_queue *queue,
613 struct xdp_frame *xdpf)
614{
615 struct netfront_info *np = netdev_priv(dev);
616 struct netfront_stats *tx_stats = this_cpu_ptr(np->tx_stats);
617 struct xennet_gnttab_make_txreq info = {
618 .queue = queue,
619 .skb = NULL,
620 .page = virt_to_page(xdpf->data),
621 };
622 int notify;
623
624 xennet_make_first_txreq(&info,
625 offset_in_page(xdpf->data),
626 xdpf->len);
627
628 xennet_mark_tx_pending(queue);
629
630 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->tx, notify);
631 if (notify)
632 notify_remote_via_irq(queue->tx_irq);
633
634 u64_stats_update_begin(&tx_stats->syncp);
635 tx_stats->bytes += xdpf->len;
636 tx_stats->packets++;
637 u64_stats_update_end(&tx_stats->syncp);
638
639 xennet_tx_buf_gc(queue);
640
641 return 0;
642}
643
644static int xennet_xdp_xmit(struct net_device *dev, int n,
645 struct xdp_frame **frames, u32 flags)
646{
647 unsigned int num_queues = dev->real_num_tx_queues;
648 struct netfront_info *np = netdev_priv(dev);
649 struct netfront_queue *queue = NULL;
650 unsigned long irq_flags;
651 int nxmit = 0;
652 int i;
653
654 if (unlikely(np->broken))
655 return -ENODEV;
656 if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK))
657 return -EINVAL;
658
659 queue = &np->queues[smp_processor_id() % num_queues];
660
661 spin_lock_irqsave(&queue->tx_lock, irq_flags);
662 for (i = 0; i < n; i++) {
663 struct xdp_frame *xdpf = frames[i];
664
665 if (!xdpf)
666 continue;
667 if (xennet_xdp_xmit_one(dev, queue, xdpf))
668 break;
669 nxmit++;
670 }
671 spin_unlock_irqrestore(&queue->tx_lock, irq_flags);
672
673 return nxmit;
674}
675
676static struct sk_buff *bounce_skb(const struct sk_buff *skb)
677{
678 unsigned int headerlen = skb_headroom(skb);
679 /* Align size to allocate full pages and avoid contiguous data leaks */
680 unsigned int size = ALIGN(skb_end_offset(skb) + skb->data_len,
681 XEN_PAGE_SIZE);
682 struct sk_buff *n = alloc_skb(size, GFP_ATOMIC | __GFP_ZERO);
683
684 if (!n)
685 return NULL;
686
687 if (!IS_ALIGNED((uintptr_t)n->head, XEN_PAGE_SIZE)) {
688 WARN_ONCE(1, "misaligned skb allocated\n");
689 kfree_skb(n);
690 return NULL;
691 }
692
693 /* Set the data pointer */
694 skb_reserve(n, headerlen);
695 /* Set the tail pointer and length */
696 skb_put(n, skb->len);
697
698 BUG_ON(skb_copy_bits(skb, -headerlen, n->head, headerlen + skb->len));
699
700 skb_copy_header(n, skb);
701 return n;
702}
703
704#define MAX_XEN_SKB_FRAGS (65536 / XEN_PAGE_SIZE + 1)
705
706static netdev_tx_t xennet_start_xmit(struct sk_buff *skb, struct net_device *dev)
707{
708 struct netfront_info *np = netdev_priv(dev);
709 struct netfront_stats *tx_stats = this_cpu_ptr(np->tx_stats);
710 struct xen_netif_tx_request *first_tx;
711 unsigned int i;
712 int notify;
713 int slots;
714 struct page *page;
715 unsigned int offset;
716 unsigned int len;
717 unsigned long flags;
718 struct netfront_queue *queue = NULL;
719 struct xennet_gnttab_make_txreq info = { };
720 unsigned int num_queues = dev->real_num_tx_queues;
721 u16 queue_index;
722 struct sk_buff *nskb;
723
724 /* Drop the packet if no queues are set up */
725 if (num_queues < 1)
726 goto drop;
727 if (unlikely(np->broken))
728 goto drop;
729 /* Determine which queue to transmit this SKB on */
730 queue_index = skb_get_queue_mapping(skb);
731 queue = &np->queues[queue_index];
732
733 /* If skb->len is too big for wire format, drop skb and alert
734 * user about misconfiguration.
735 */
736 if (unlikely(skb->len > XEN_NETIF_MAX_TX_SIZE)) {
737 net_alert_ratelimited(
738 "xennet: skb->len = %u, too big for wire format\n",
739 skb->len);
740 goto drop;
741 }
742
743 slots = xennet_count_skb_slots(skb);
744 if (unlikely(slots > MAX_XEN_SKB_FRAGS + 1)) {
745 net_dbg_ratelimited("xennet: skb rides the rocket: %d slots, %d bytes\n",
746 slots, skb->len);
747 if (skb_linearize(skb))
748 goto drop;
749 }
750
751 page = virt_to_page(skb->data);
752 offset = offset_in_page(skb->data);
753
754 /* The first req should be at least ETH_HLEN size or the packet will be
755 * dropped by netback.
756 *
757 * If the backend is not trusted bounce all data to zeroed pages to
758 * avoid exposing contiguous data on the granted page not belonging to
759 * the skb.
760 */
761 if (np->bounce || unlikely(PAGE_SIZE - offset < ETH_HLEN)) {
762 nskb = bounce_skb(skb);
763 if (!nskb)
764 goto drop;
765 dev_consume_skb_any(skb);
766 skb = nskb;
767 page = virt_to_page(skb->data);
768 offset = offset_in_page(skb->data);
769 }
770
771 len = skb_headlen(skb);
772
773 spin_lock_irqsave(&queue->tx_lock, flags);
774
775 if (unlikely(!netif_carrier_ok(dev) ||
776 (slots > 1 && !xennet_can_sg(dev)) ||
777 netif_needs_gso(skb, netif_skb_features(skb)))) {
778 spin_unlock_irqrestore(&queue->tx_lock, flags);
779 goto drop;
780 }
781
782 /* First request for the linear area. */
783 info.queue = queue;
784 info.skb = skb;
785 info.page = page;
786 first_tx = xennet_make_first_txreq(&info, offset, len);
787 offset += info.tx_local.size;
788 if (offset == PAGE_SIZE) {
789 page++;
790 offset = 0;
791 }
792 len -= info.tx_local.size;
793
794 if (skb->ip_summed == CHECKSUM_PARTIAL)
795 /* local packet? */
796 first_tx->flags |= XEN_NETTXF_csum_blank |
797 XEN_NETTXF_data_validated;
798 else if (skb->ip_summed == CHECKSUM_UNNECESSARY)
799 /* remote but checksummed. */
800 first_tx->flags |= XEN_NETTXF_data_validated;
801
802 /* Optional extra info after the first request. */
803 if (skb_shinfo(skb)->gso_size) {
804 struct xen_netif_extra_info *gso;
805
806 gso = (struct xen_netif_extra_info *)
807 RING_GET_REQUEST(&queue->tx, queue->tx.req_prod_pvt++);
808
809 first_tx->flags |= XEN_NETTXF_extra_info;
810
811 gso->u.gso.size = skb_shinfo(skb)->gso_size;
812 gso->u.gso.type = (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6) ?
813 XEN_NETIF_GSO_TYPE_TCPV6 :
814 XEN_NETIF_GSO_TYPE_TCPV4;
815 gso->u.gso.pad = 0;
816 gso->u.gso.features = 0;
817
818 gso->type = XEN_NETIF_EXTRA_TYPE_GSO;
819 gso->flags = 0;
820 }
821
822 /* Requests for the rest of the linear area. */
823 xennet_make_txreqs(&info, page, offset, len);
824
825 /* Requests for all the frags. */
826 for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
827 skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
828 xennet_make_txreqs(&info, skb_frag_page(frag),
829 skb_frag_off(frag),
830 skb_frag_size(frag));
831 }
832
833 /* First request has the packet length. */
834 first_tx->size = skb->len;
835
836 /* timestamp packet in software */
837 skb_tx_timestamp(skb);
838
839 xennet_mark_tx_pending(queue);
840
841 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->tx, notify);
842 if (notify)
843 notify_remote_via_irq(queue->tx_irq);
844
845 u64_stats_update_begin(&tx_stats->syncp);
846 tx_stats->bytes += skb->len;
847 tx_stats->packets++;
848 u64_stats_update_end(&tx_stats->syncp);
849
850 /* Note: It is not safe to access skb after xennet_tx_buf_gc()! */
851 xennet_tx_buf_gc(queue);
852
853 if (!netfront_tx_slot_available(queue))
854 netif_tx_stop_queue(netdev_get_tx_queue(dev, queue->id));
855
856 spin_unlock_irqrestore(&queue->tx_lock, flags);
857
858 return NETDEV_TX_OK;
859
860 drop:
861 dev->stats.tx_dropped++;
862 dev_kfree_skb_any(skb);
863 return NETDEV_TX_OK;
864}
865
866static int xennet_close(struct net_device *dev)
867{
868 struct netfront_info *np = netdev_priv(dev);
869 unsigned int num_queues = dev->real_num_tx_queues;
870 unsigned int i;
871 struct netfront_queue *queue;
872 netif_tx_stop_all_queues(np->netdev);
873 for (i = 0; i < num_queues; ++i) {
874 queue = &np->queues[i];
875 napi_disable(&queue->napi);
876 }
877 return 0;
878}
879
880static void xennet_destroy_queues(struct netfront_info *info)
881{
882 unsigned int i;
883
884 for (i = 0; i < info->netdev->real_num_tx_queues; i++) {
885 struct netfront_queue *queue = &info->queues[i];
886
887 if (netif_running(info->netdev))
888 napi_disable(&queue->napi);
889 netif_napi_del(&queue->napi);
890 }
891
892 kfree(info->queues);
893 info->queues = NULL;
894}
895
896static void xennet_uninit(struct net_device *dev)
897{
898 struct netfront_info *np = netdev_priv(dev);
899 xennet_destroy_queues(np);
900}
901
902static void xennet_set_rx_rsp_cons(struct netfront_queue *queue, RING_IDX val)
903{
904 unsigned long flags;
905
906 spin_lock_irqsave(&queue->rx_cons_lock, flags);
907 queue->rx.rsp_cons = val;
908 queue->rx_rsp_unconsumed = XEN_RING_NR_UNCONSUMED_RESPONSES(&queue->rx);
909 spin_unlock_irqrestore(&queue->rx_cons_lock, flags);
910}
911
912static void xennet_move_rx_slot(struct netfront_queue *queue, struct sk_buff *skb,
913 grant_ref_t ref)
914{
915 int new = xennet_rxidx(queue->rx.req_prod_pvt);
916
917 BUG_ON(queue->rx_skbs[new]);
918 queue->rx_skbs[new] = skb;
919 queue->grant_rx_ref[new] = ref;
920 RING_GET_REQUEST(&queue->rx, queue->rx.req_prod_pvt)->id = new;
921 RING_GET_REQUEST(&queue->rx, queue->rx.req_prod_pvt)->gref = ref;
922 queue->rx.req_prod_pvt++;
923}
924
925static int xennet_get_extras(struct netfront_queue *queue,
926 struct xen_netif_extra_info *extras,
927 RING_IDX rp)
928
929{
930 struct xen_netif_extra_info extra;
931 struct device *dev = &queue->info->netdev->dev;
932 RING_IDX cons = queue->rx.rsp_cons;
933 int err = 0;
934
935 do {
936 struct sk_buff *skb;
937 grant_ref_t ref;
938
939 if (unlikely(cons + 1 == rp)) {
940 if (net_ratelimit())
941 dev_warn(dev, "Missing extra info\n");
942 err = -EBADR;
943 break;
944 }
945
946 RING_COPY_RESPONSE(&queue->rx, ++cons, &extra);
947
948 if (unlikely(!extra.type ||
949 extra.type >= XEN_NETIF_EXTRA_TYPE_MAX)) {
950 if (net_ratelimit())
951 dev_warn(dev, "Invalid extra type: %d\n",
952 extra.type);
953 err = -EINVAL;
954 } else {
955 extras[extra.type - 1] = extra;
956 }
957
958 skb = xennet_get_rx_skb(queue, cons);
959 ref = xennet_get_rx_ref(queue, cons);
960 xennet_move_rx_slot(queue, skb, ref);
961 } while (extra.flags & XEN_NETIF_EXTRA_FLAG_MORE);
962
963 xennet_set_rx_rsp_cons(queue, cons);
964 return err;
965}
966
967static u32 xennet_run_xdp(struct netfront_queue *queue, struct page *pdata,
968 struct xen_netif_rx_response *rx, struct bpf_prog *prog,
969 struct xdp_buff *xdp, bool *need_xdp_flush)
970{
971 struct xdp_frame *xdpf;
972 u32 len = rx->status;
973 u32 act;
974 int err;
975
976 xdp_init_buff(xdp, XEN_PAGE_SIZE - XDP_PACKET_HEADROOM,
977 &queue->xdp_rxq);
978 xdp_prepare_buff(xdp, page_address(pdata), XDP_PACKET_HEADROOM,
979 len, false);
980
981 act = bpf_prog_run_xdp(prog, xdp);
982 switch (act) {
983 case XDP_TX:
984 get_page(pdata);
985 xdpf = xdp_convert_buff_to_frame(xdp);
986 err = xennet_xdp_xmit(queue->info->netdev, 1, &xdpf, 0);
987 if (unlikely(!err))
988 xdp_return_frame_rx_napi(xdpf);
989 else if (unlikely(err < 0))
990 trace_xdp_exception(queue->info->netdev, prog, act);
991 break;
992 case XDP_REDIRECT:
993 get_page(pdata);
994 err = xdp_do_redirect(queue->info->netdev, xdp, prog);
995 *need_xdp_flush = true;
996 if (unlikely(err))
997 trace_xdp_exception(queue->info->netdev, prog, act);
998 break;
999 case XDP_PASS:
1000 case XDP_DROP:
1001 break;
1002
1003 case XDP_ABORTED:
1004 trace_xdp_exception(queue->info->netdev, prog, act);
1005 break;
1006
1007 default:
1008 bpf_warn_invalid_xdp_action(queue->info->netdev, prog, act);
1009 }
1010
1011 return act;
1012}
1013
1014static int xennet_get_responses(struct netfront_queue *queue,
1015 struct netfront_rx_info *rinfo, RING_IDX rp,
1016 struct sk_buff_head *list,
1017 bool *need_xdp_flush)
1018{
1019 struct xen_netif_rx_response *rx = &rinfo->rx, rx_local;
1020 int max = XEN_NETIF_NR_SLOTS_MIN + (rx->status <= RX_COPY_THRESHOLD);
1021 RING_IDX cons = queue->rx.rsp_cons;
1022 struct sk_buff *skb = xennet_get_rx_skb(queue, cons);
1023 struct xen_netif_extra_info *extras = rinfo->extras;
1024 grant_ref_t ref = xennet_get_rx_ref(queue, cons);
1025 struct device *dev = &queue->info->netdev->dev;
1026 struct bpf_prog *xdp_prog;
1027 struct xdp_buff xdp;
1028 int slots = 1;
1029 int err = 0;
1030 u32 verdict;
1031
1032 if (rx->flags & XEN_NETRXF_extra_info) {
1033 err = xennet_get_extras(queue, extras, rp);
1034 if (!err) {
1035 if (extras[XEN_NETIF_EXTRA_TYPE_XDP - 1].type) {
1036 struct xen_netif_extra_info *xdp;
1037
1038 xdp = &extras[XEN_NETIF_EXTRA_TYPE_XDP - 1];
1039 rx->offset = xdp->u.xdp.headroom;
1040 }
1041 }
1042 cons = queue->rx.rsp_cons;
1043 }
1044
1045 for (;;) {
1046 /*
1047 * This definitely indicates a bug, either in this driver or in
1048 * the backend driver. In future this should flag the bad
1049 * situation to the system controller to reboot the backend.
1050 */
1051 if (ref == INVALID_GRANT_REF) {
1052 if (net_ratelimit())
1053 dev_warn(dev, "Bad rx response id %d.\n",
1054 rx->id);
1055 err = -EINVAL;
1056 goto next;
1057 }
1058
1059 if (unlikely(rx->status < 0 ||
1060 rx->offset + rx->status > XEN_PAGE_SIZE)) {
1061 if (net_ratelimit())
1062 dev_warn(dev, "rx->offset: %u, size: %d\n",
1063 rx->offset, rx->status);
1064 xennet_move_rx_slot(queue, skb, ref);
1065 err = -EINVAL;
1066 goto next;
1067 }
1068
1069 if (!gnttab_end_foreign_access_ref(ref)) {
1070 dev_alert(dev,
1071 "Grant still in use by backend domain\n");
1072 queue->info->broken = true;
1073 dev_alert(dev, "Disabled for further use\n");
1074 return -EINVAL;
1075 }
1076
1077 gnttab_release_grant_reference(&queue->gref_rx_head, ref);
1078
1079 rcu_read_lock();
1080 xdp_prog = rcu_dereference(queue->xdp_prog);
1081 if (xdp_prog) {
1082 if (!(rx->flags & XEN_NETRXF_more_data)) {
1083 /* currently only a single page contains data */
1084 verdict = xennet_run_xdp(queue,
1085 skb_frag_page(&skb_shinfo(skb)->frags[0]),
1086 rx, xdp_prog, &xdp, need_xdp_flush);
1087 if (verdict != XDP_PASS)
1088 err = -EINVAL;
1089 } else {
1090 /* drop the frame */
1091 err = -EINVAL;
1092 }
1093 }
1094 rcu_read_unlock();
1095
1096 __skb_queue_tail(list, skb);
1097
1098next:
1099 if (!(rx->flags & XEN_NETRXF_more_data))
1100 break;
1101
1102 if (cons + slots == rp) {
1103 if (net_ratelimit())
1104 dev_warn(dev, "Need more slots\n");
1105 err = -ENOENT;
1106 break;
1107 }
1108
1109 RING_COPY_RESPONSE(&queue->rx, cons + slots, &rx_local);
1110 rx = &rx_local;
1111 skb = xennet_get_rx_skb(queue, cons + slots);
1112 ref = xennet_get_rx_ref(queue, cons + slots);
1113 slots++;
1114 }
1115
1116 if (unlikely(slots > max)) {
1117 if (net_ratelimit())
1118 dev_warn(dev, "Too many slots\n");
1119 err = -E2BIG;
1120 }
1121
1122 if (unlikely(err))
1123 xennet_set_rx_rsp_cons(queue, cons + slots);
1124
1125 return err;
1126}
1127
1128static int xennet_set_skb_gso(struct sk_buff *skb,
1129 struct xen_netif_extra_info *gso)
1130{
1131 if (!gso->u.gso.size) {
1132 if (net_ratelimit())
1133 pr_warn("GSO size must not be zero\n");
1134 return -EINVAL;
1135 }
1136
1137 if (gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV4 &&
1138 gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV6) {
1139 if (net_ratelimit())
1140 pr_warn("Bad GSO type %d\n", gso->u.gso.type);
1141 return -EINVAL;
1142 }
1143
1144 skb_shinfo(skb)->gso_size = gso->u.gso.size;
1145 skb_shinfo(skb)->gso_type =
1146 (gso->u.gso.type == XEN_NETIF_GSO_TYPE_TCPV4) ?
1147 SKB_GSO_TCPV4 :
1148 SKB_GSO_TCPV6;
1149
1150 /* Header must be checked, and gso_segs computed. */
1151 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
1152 skb_shinfo(skb)->gso_segs = 0;
1153
1154 return 0;
1155}
1156
1157static int xennet_fill_frags(struct netfront_queue *queue,
1158 struct sk_buff *skb,
1159 struct sk_buff_head *list)
1160{
1161 RING_IDX cons = queue->rx.rsp_cons;
1162 struct sk_buff *nskb;
1163
1164 while ((nskb = __skb_dequeue(list))) {
1165 struct xen_netif_rx_response rx;
1166 skb_frag_t *nfrag = &skb_shinfo(nskb)->frags[0];
1167
1168 RING_COPY_RESPONSE(&queue->rx, ++cons, &rx);
1169
1170 if (skb_shinfo(skb)->nr_frags == MAX_SKB_FRAGS) {
1171 unsigned int pull_to = NETFRONT_SKB_CB(skb)->pull_to;
1172
1173 BUG_ON(pull_to < skb_headlen(skb));
1174 __pskb_pull_tail(skb, pull_to - skb_headlen(skb));
1175 }
1176 if (unlikely(skb_shinfo(skb)->nr_frags >= MAX_SKB_FRAGS)) {
1177 xennet_set_rx_rsp_cons(queue,
1178 ++cons + skb_queue_len(list));
1179 kfree_skb(nskb);
1180 return -ENOENT;
1181 }
1182
1183 skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags,
1184 skb_frag_page(nfrag),
1185 rx.offset, rx.status, PAGE_SIZE);
1186
1187 skb_shinfo(nskb)->nr_frags = 0;
1188 kfree_skb(nskb);
1189 }
1190
1191 xennet_set_rx_rsp_cons(queue, cons);
1192
1193 return 0;
1194}
1195
1196static int checksum_setup(struct net_device *dev, struct sk_buff *skb)
1197{
1198 bool recalculate_partial_csum = false;
1199
1200 /*
1201 * A GSO SKB must be CHECKSUM_PARTIAL. However some buggy
1202 * peers can fail to set NETRXF_csum_blank when sending a GSO
1203 * frame. In this case force the SKB to CHECKSUM_PARTIAL and
1204 * recalculate the partial checksum.
1205 */
1206 if (skb->ip_summed != CHECKSUM_PARTIAL && skb_is_gso(skb)) {
1207 struct netfront_info *np = netdev_priv(dev);
1208 atomic_inc(&np->rx_gso_checksum_fixup);
1209 skb->ip_summed = CHECKSUM_PARTIAL;
1210 recalculate_partial_csum = true;
1211 }
1212
1213 /* A non-CHECKSUM_PARTIAL SKB does not require setup. */
1214 if (skb->ip_summed != CHECKSUM_PARTIAL)
1215 return 0;
1216
1217 return skb_checksum_setup(skb, recalculate_partial_csum);
1218}
1219
1220static int handle_incoming_queue(struct netfront_queue *queue,
1221 struct sk_buff_head *rxq)
1222{
1223 struct netfront_stats *rx_stats = this_cpu_ptr(queue->info->rx_stats);
1224 int packets_dropped = 0;
1225 struct sk_buff *skb;
1226
1227 while ((skb = __skb_dequeue(rxq)) != NULL) {
1228 int pull_to = NETFRONT_SKB_CB(skb)->pull_to;
1229
1230 if (pull_to > skb_headlen(skb))
1231 __pskb_pull_tail(skb, pull_to - skb_headlen(skb));
1232
1233 /* Ethernet work: Delayed to here as it peeks the header. */
1234 skb->protocol = eth_type_trans(skb, queue->info->netdev);
1235 skb_reset_network_header(skb);
1236
1237 if (checksum_setup(queue->info->netdev, skb)) {
1238 kfree_skb(skb);
1239 packets_dropped++;
1240 queue->info->netdev->stats.rx_errors++;
1241 continue;
1242 }
1243
1244 u64_stats_update_begin(&rx_stats->syncp);
1245 rx_stats->packets++;
1246 rx_stats->bytes += skb->len;
1247 u64_stats_update_end(&rx_stats->syncp);
1248
1249 /* Pass it up. */
1250 napi_gro_receive(&queue->napi, skb);
1251 }
1252
1253 return packets_dropped;
1254}
1255
1256static int xennet_poll(struct napi_struct *napi, int budget)
1257{
1258 struct netfront_queue *queue = container_of(napi, struct netfront_queue, napi);
1259 struct net_device *dev = queue->info->netdev;
1260 struct sk_buff *skb;
1261 struct netfront_rx_info rinfo;
1262 struct xen_netif_rx_response *rx = &rinfo.rx;
1263 struct xen_netif_extra_info *extras = rinfo.extras;
1264 RING_IDX i, rp;
1265 int work_done;
1266 struct sk_buff_head rxq;
1267 struct sk_buff_head errq;
1268 struct sk_buff_head tmpq;
1269 int err;
1270 bool need_xdp_flush = false;
1271
1272 spin_lock(&queue->rx_lock);
1273
1274 skb_queue_head_init(&rxq);
1275 skb_queue_head_init(&errq);
1276 skb_queue_head_init(&tmpq);
1277
1278 rp = queue->rx.sring->rsp_prod;
1279 if (RING_RESPONSE_PROD_OVERFLOW(&queue->rx, rp)) {
1280 dev_alert(&dev->dev, "Illegal number of responses %u\n",
1281 rp - queue->rx.rsp_cons);
1282 queue->info->broken = true;
1283 spin_unlock(&queue->rx_lock);
1284 return 0;
1285 }
1286 rmb(); /* Ensure we see queued responses up to 'rp'. */
1287
1288 i = queue->rx.rsp_cons;
1289 work_done = 0;
1290 while ((i != rp) && (work_done < budget)) {
1291 RING_COPY_RESPONSE(&queue->rx, i, rx);
1292 memset(extras, 0, sizeof(rinfo.extras));
1293
1294 err = xennet_get_responses(queue, &rinfo, rp, &tmpq,
1295 &need_xdp_flush);
1296
1297 if (unlikely(err)) {
1298 if (queue->info->broken) {
1299 spin_unlock(&queue->rx_lock);
1300 return 0;
1301 }
1302err:
1303 while ((skb = __skb_dequeue(&tmpq)))
1304 __skb_queue_tail(&errq, skb);
1305 dev->stats.rx_errors++;
1306 i = queue->rx.rsp_cons;
1307 continue;
1308 }
1309
1310 skb = __skb_dequeue(&tmpq);
1311
1312 if (extras[XEN_NETIF_EXTRA_TYPE_GSO - 1].type) {
1313 struct xen_netif_extra_info *gso;
1314 gso = &extras[XEN_NETIF_EXTRA_TYPE_GSO - 1];
1315
1316 if (unlikely(xennet_set_skb_gso(skb, gso))) {
1317 __skb_queue_head(&tmpq, skb);
1318 xennet_set_rx_rsp_cons(queue,
1319 queue->rx.rsp_cons +
1320 skb_queue_len(&tmpq));
1321 goto err;
1322 }
1323 }
1324
1325 NETFRONT_SKB_CB(skb)->pull_to = rx->status;
1326 if (NETFRONT_SKB_CB(skb)->pull_to > RX_COPY_THRESHOLD)
1327 NETFRONT_SKB_CB(skb)->pull_to = RX_COPY_THRESHOLD;
1328
1329 skb_frag_off_set(&skb_shinfo(skb)->frags[0], rx->offset);
1330 skb_frag_size_set(&skb_shinfo(skb)->frags[0], rx->status);
1331 skb->data_len = rx->status;
1332 skb->len += rx->status;
1333
1334 if (unlikely(xennet_fill_frags(queue, skb, &tmpq)))
1335 goto err;
1336
1337 if (rx->flags & XEN_NETRXF_csum_blank)
1338 skb->ip_summed = CHECKSUM_PARTIAL;
1339 else if (rx->flags & XEN_NETRXF_data_validated)
1340 skb->ip_summed = CHECKSUM_UNNECESSARY;
1341
1342 __skb_queue_tail(&rxq, skb);
1343
1344 i = queue->rx.rsp_cons + 1;
1345 xennet_set_rx_rsp_cons(queue, i);
1346 work_done++;
1347 }
1348 if (need_xdp_flush)
1349 xdp_do_flush();
1350
1351 __skb_queue_purge(&errq);
1352
1353 work_done -= handle_incoming_queue(queue, &rxq);
1354
1355 xennet_alloc_rx_buffers(queue);
1356
1357 if (work_done < budget) {
1358 int more_to_do = 0;
1359
1360 napi_complete_done(napi, work_done);
1361
1362 RING_FINAL_CHECK_FOR_RESPONSES(&queue->rx, more_to_do);
1363 if (more_to_do)
1364 napi_schedule(napi);
1365 }
1366
1367 spin_unlock(&queue->rx_lock);
1368
1369 return work_done;
1370}
1371
1372static int xennet_change_mtu(struct net_device *dev, int mtu)
1373{
1374 int max = xennet_can_sg(dev) ? XEN_NETIF_MAX_TX_SIZE : ETH_DATA_LEN;
1375
1376 if (mtu > max)
1377 return -EINVAL;
1378 dev->mtu = mtu;
1379 return 0;
1380}
1381
1382static void xennet_get_stats64(struct net_device *dev,
1383 struct rtnl_link_stats64 *tot)
1384{
1385 struct netfront_info *np = netdev_priv(dev);
1386 int cpu;
1387
1388 for_each_possible_cpu(cpu) {
1389 struct netfront_stats *rx_stats = per_cpu_ptr(np->rx_stats, cpu);
1390 struct netfront_stats *tx_stats = per_cpu_ptr(np->tx_stats, cpu);
1391 u64 rx_packets, rx_bytes, tx_packets, tx_bytes;
1392 unsigned int start;
1393
1394 do {
1395 start = u64_stats_fetch_begin(&tx_stats->syncp);
1396 tx_packets = tx_stats->packets;
1397 tx_bytes = tx_stats->bytes;
1398 } while (u64_stats_fetch_retry(&tx_stats->syncp, start));
1399
1400 do {
1401 start = u64_stats_fetch_begin(&rx_stats->syncp);
1402 rx_packets = rx_stats->packets;
1403 rx_bytes = rx_stats->bytes;
1404 } while (u64_stats_fetch_retry(&rx_stats->syncp, start));
1405
1406 tot->rx_packets += rx_packets;
1407 tot->tx_packets += tx_packets;
1408 tot->rx_bytes += rx_bytes;
1409 tot->tx_bytes += tx_bytes;
1410 }
1411
1412 tot->rx_errors = dev->stats.rx_errors;
1413 tot->tx_dropped = dev->stats.tx_dropped;
1414}
1415
1416static void xennet_release_tx_bufs(struct netfront_queue *queue)
1417{
1418 struct sk_buff *skb;
1419 int i;
1420
1421 for (i = 0; i < NET_TX_RING_SIZE; i++) {
1422 /* Skip over entries which are actually freelist references */
1423 if (!queue->tx_skbs[i])
1424 continue;
1425
1426 skb = queue->tx_skbs[i];
1427 queue->tx_skbs[i] = NULL;
1428 get_page(queue->grant_tx_page[i]);
1429 gnttab_end_foreign_access(queue->grant_tx_ref[i],
1430 queue->grant_tx_page[i]);
1431 queue->grant_tx_page[i] = NULL;
1432 queue->grant_tx_ref[i] = INVALID_GRANT_REF;
1433 add_id_to_list(&queue->tx_skb_freelist, queue->tx_link, i);
1434 dev_kfree_skb_irq(skb);
1435 }
1436}
1437
1438static void xennet_release_rx_bufs(struct netfront_queue *queue)
1439{
1440 int id, ref;
1441
1442 spin_lock_bh(&queue->rx_lock);
1443
1444 for (id = 0; id < NET_RX_RING_SIZE; id++) {
1445 struct sk_buff *skb;
1446 struct page *page;
1447
1448 skb = queue->rx_skbs[id];
1449 if (!skb)
1450 continue;
1451
1452 ref = queue->grant_rx_ref[id];
1453 if (ref == INVALID_GRANT_REF)
1454 continue;
1455
1456 page = skb_frag_page(&skb_shinfo(skb)->frags[0]);
1457
1458 /* gnttab_end_foreign_access() needs a page ref until
1459 * foreign access is ended (which may be deferred).
1460 */
1461 get_page(page);
1462 gnttab_end_foreign_access(ref, page);
1463 queue->grant_rx_ref[id] = INVALID_GRANT_REF;
1464
1465 kfree_skb(skb);
1466 }
1467
1468 spin_unlock_bh(&queue->rx_lock);
1469}
1470
1471static netdev_features_t xennet_fix_features(struct net_device *dev,
1472 netdev_features_t features)
1473{
1474 struct netfront_info *np = netdev_priv(dev);
1475
1476 if (features & NETIF_F_SG &&
1477 !xenbus_read_unsigned(np->xbdev->otherend, "feature-sg", 0))
1478 features &= ~NETIF_F_SG;
1479
1480 if (features & NETIF_F_IPV6_CSUM &&
1481 !xenbus_read_unsigned(np->xbdev->otherend,
1482 "feature-ipv6-csum-offload", 0))
1483 features &= ~NETIF_F_IPV6_CSUM;
1484
1485 if (features & NETIF_F_TSO &&
1486 !xenbus_read_unsigned(np->xbdev->otherend, "feature-gso-tcpv4", 0))
1487 features &= ~NETIF_F_TSO;
1488
1489 if (features & NETIF_F_TSO6 &&
1490 !xenbus_read_unsigned(np->xbdev->otherend, "feature-gso-tcpv6", 0))
1491 features &= ~NETIF_F_TSO6;
1492
1493 return features;
1494}
1495
1496static int xennet_set_features(struct net_device *dev,
1497 netdev_features_t features)
1498{
1499 if (!(features & NETIF_F_SG) && dev->mtu > ETH_DATA_LEN) {
1500 netdev_info(dev, "Reducing MTU because no SG offload");
1501 dev->mtu = ETH_DATA_LEN;
1502 }
1503
1504 return 0;
1505}
1506
1507static bool xennet_handle_tx(struct netfront_queue *queue, unsigned int *eoi)
1508{
1509 unsigned long flags;
1510
1511 if (unlikely(queue->info->broken))
1512 return false;
1513
1514 spin_lock_irqsave(&queue->tx_lock, flags);
1515 if (xennet_tx_buf_gc(queue))
1516 *eoi = 0;
1517 spin_unlock_irqrestore(&queue->tx_lock, flags);
1518
1519 return true;
1520}
1521
1522static irqreturn_t xennet_tx_interrupt(int irq, void *dev_id)
1523{
1524 unsigned int eoiflag = XEN_EOI_FLAG_SPURIOUS;
1525
1526 if (likely(xennet_handle_tx(dev_id, &eoiflag)))
1527 xen_irq_lateeoi(irq, eoiflag);
1528
1529 return IRQ_HANDLED;
1530}
1531
1532static bool xennet_handle_rx(struct netfront_queue *queue, unsigned int *eoi)
1533{
1534 unsigned int work_queued;
1535 unsigned long flags;
1536
1537 if (unlikely(queue->info->broken))
1538 return false;
1539
1540 spin_lock_irqsave(&queue->rx_cons_lock, flags);
1541 work_queued = XEN_RING_NR_UNCONSUMED_RESPONSES(&queue->rx);
1542 if (work_queued > queue->rx_rsp_unconsumed) {
1543 queue->rx_rsp_unconsumed = work_queued;
1544 *eoi = 0;
1545 } else if (unlikely(work_queued < queue->rx_rsp_unconsumed)) {
1546 const struct device *dev = &queue->info->netdev->dev;
1547
1548 spin_unlock_irqrestore(&queue->rx_cons_lock, flags);
1549 dev_alert(dev, "RX producer index going backwards\n");
1550 dev_alert(dev, "Disabled for further use\n");
1551 queue->info->broken = true;
1552 return false;
1553 }
1554 spin_unlock_irqrestore(&queue->rx_cons_lock, flags);
1555
1556 if (likely(netif_carrier_ok(queue->info->netdev) && work_queued))
1557 napi_schedule(&queue->napi);
1558
1559 return true;
1560}
1561
1562static irqreturn_t xennet_rx_interrupt(int irq, void *dev_id)
1563{
1564 unsigned int eoiflag = XEN_EOI_FLAG_SPURIOUS;
1565
1566 if (likely(xennet_handle_rx(dev_id, &eoiflag)))
1567 xen_irq_lateeoi(irq, eoiflag);
1568
1569 return IRQ_HANDLED;
1570}
1571
1572static irqreturn_t xennet_interrupt(int irq, void *dev_id)
1573{
1574 unsigned int eoiflag = XEN_EOI_FLAG_SPURIOUS;
1575
1576 if (xennet_handle_tx(dev_id, &eoiflag) &&
1577 xennet_handle_rx(dev_id, &eoiflag))
1578 xen_irq_lateeoi(irq, eoiflag);
1579
1580 return IRQ_HANDLED;
1581}
1582
1583#ifdef CONFIG_NET_POLL_CONTROLLER
1584static void xennet_poll_controller(struct net_device *dev)
1585{
1586 /* Poll each queue */
1587 struct netfront_info *info = netdev_priv(dev);
1588 unsigned int num_queues = dev->real_num_tx_queues;
1589 unsigned int i;
1590
1591 if (info->broken)
1592 return;
1593
1594 for (i = 0; i < num_queues; ++i)
1595 xennet_interrupt(0, &info->queues[i]);
1596}
1597#endif
1598
1599#define NETBACK_XDP_HEADROOM_DISABLE 0
1600#define NETBACK_XDP_HEADROOM_ENABLE 1
1601
1602static int talk_to_netback_xdp(struct netfront_info *np, int xdp)
1603{
1604 int err;
1605 unsigned short headroom;
1606
1607 headroom = xdp ? XDP_PACKET_HEADROOM : 0;
1608 err = xenbus_printf(XBT_NIL, np->xbdev->nodename,
1609 "xdp-headroom", "%hu",
1610 headroom);
1611 if (err)
1612 pr_warn("Error writing xdp-headroom\n");
1613
1614 return err;
1615}
1616
1617static int xennet_xdp_set(struct net_device *dev, struct bpf_prog *prog,
1618 struct netlink_ext_ack *extack)
1619{
1620 unsigned long max_mtu = XEN_PAGE_SIZE - XDP_PACKET_HEADROOM;
1621 struct netfront_info *np = netdev_priv(dev);
1622 struct bpf_prog *old_prog;
1623 unsigned int i, err;
1624
1625 if (dev->mtu > max_mtu) {
1626 netdev_warn(dev, "XDP requires MTU less than %lu\n", max_mtu);
1627 return -EINVAL;
1628 }
1629
1630 if (!np->netback_has_xdp_headroom)
1631 return 0;
1632
1633 xenbus_switch_state(np->xbdev, XenbusStateReconfiguring);
1634
1635 err = talk_to_netback_xdp(np, prog ? NETBACK_XDP_HEADROOM_ENABLE :
1636 NETBACK_XDP_HEADROOM_DISABLE);
1637 if (err)
1638 return err;
1639
1640 /* avoid the race with XDP headroom adjustment */
1641 wait_event(module_wq,
1642 xenbus_read_driver_state(np->xbdev->otherend) ==
1643 XenbusStateReconfigured);
1644 np->netfront_xdp_enabled = true;
1645
1646 old_prog = rtnl_dereference(np->queues[0].xdp_prog);
1647
1648 if (prog)
1649 bpf_prog_add(prog, dev->real_num_tx_queues);
1650
1651 for (i = 0; i < dev->real_num_tx_queues; ++i)
1652 rcu_assign_pointer(np->queues[i].xdp_prog, prog);
1653
1654 if (old_prog)
1655 for (i = 0; i < dev->real_num_tx_queues; ++i)
1656 bpf_prog_put(old_prog);
1657
1658 xenbus_switch_state(np->xbdev, XenbusStateConnected);
1659
1660 return 0;
1661}
1662
1663static int xennet_xdp(struct net_device *dev, struct netdev_bpf *xdp)
1664{
1665 struct netfront_info *np = netdev_priv(dev);
1666
1667 if (np->broken)
1668 return -ENODEV;
1669
1670 switch (xdp->command) {
1671 case XDP_SETUP_PROG:
1672 return xennet_xdp_set(dev, xdp->prog, xdp->extack);
1673 default:
1674 return -EINVAL;
1675 }
1676}
1677
1678static const struct net_device_ops xennet_netdev_ops = {
1679 .ndo_uninit = xennet_uninit,
1680 .ndo_open = xennet_open,
1681 .ndo_stop = xennet_close,
1682 .ndo_start_xmit = xennet_start_xmit,
1683 .ndo_change_mtu = xennet_change_mtu,
1684 .ndo_get_stats64 = xennet_get_stats64,
1685 .ndo_set_mac_address = eth_mac_addr,
1686 .ndo_validate_addr = eth_validate_addr,
1687 .ndo_fix_features = xennet_fix_features,
1688 .ndo_set_features = xennet_set_features,
1689 .ndo_select_queue = xennet_select_queue,
1690 .ndo_bpf = xennet_xdp,
1691 .ndo_xdp_xmit = xennet_xdp_xmit,
1692#ifdef CONFIG_NET_POLL_CONTROLLER
1693 .ndo_poll_controller = xennet_poll_controller,
1694#endif
1695};
1696
1697static void xennet_free_netdev(struct net_device *netdev)
1698{
1699 struct netfront_info *np = netdev_priv(netdev);
1700
1701 free_percpu(np->rx_stats);
1702 free_percpu(np->tx_stats);
1703 free_netdev(netdev);
1704}
1705
1706static struct net_device *xennet_create_dev(struct xenbus_device *dev)
1707{
1708 int err;
1709 struct net_device *netdev;
1710 struct netfront_info *np;
1711
1712 netdev = alloc_etherdev_mq(sizeof(struct netfront_info), xennet_max_queues);
1713 if (!netdev)
1714 return ERR_PTR(-ENOMEM);
1715
1716 np = netdev_priv(netdev);
1717 np->xbdev = dev;
1718
1719 np->queues = NULL;
1720
1721 err = -ENOMEM;
1722 np->rx_stats = netdev_alloc_pcpu_stats(struct netfront_stats);
1723 if (np->rx_stats == NULL)
1724 goto exit;
1725 np->tx_stats = netdev_alloc_pcpu_stats(struct netfront_stats);
1726 if (np->tx_stats == NULL)
1727 goto exit;
1728
1729 netdev->netdev_ops = &xennet_netdev_ops;
1730
1731 netdev->features = NETIF_F_IP_CSUM | NETIF_F_RXCSUM |
1732 NETIF_F_GSO_ROBUST;
1733 netdev->hw_features = NETIF_F_SG |
1734 NETIF_F_IPV6_CSUM |
1735 NETIF_F_TSO | NETIF_F_TSO6;
1736
1737 /*
1738 * Assume that all hw features are available for now. This set
1739 * will be adjusted by the call to netdev_update_features() in
1740 * xennet_connect() which is the earliest point where we can
1741 * negotiate with the backend regarding supported features.
1742 */
1743 netdev->features |= netdev->hw_features;
1744 netdev->xdp_features = NETDEV_XDP_ACT_BASIC | NETDEV_XDP_ACT_REDIRECT |
1745 NETDEV_XDP_ACT_NDO_XMIT;
1746
1747 netdev->ethtool_ops = &xennet_ethtool_ops;
1748 netdev->min_mtu = ETH_MIN_MTU;
1749 netdev->max_mtu = XEN_NETIF_MAX_TX_SIZE;
1750 SET_NETDEV_DEV(netdev, &dev->dev);
1751
1752 np->netdev = netdev;
1753 np->netfront_xdp_enabled = false;
1754
1755 netif_carrier_off(netdev);
1756
1757 do {
1758 xenbus_switch_state(dev, XenbusStateInitialising);
1759 err = wait_event_timeout(module_wq,
1760 xenbus_read_driver_state(dev->otherend) !=
1761 XenbusStateClosed &&
1762 xenbus_read_driver_state(dev->otherend) !=
1763 XenbusStateUnknown, XENNET_TIMEOUT);
1764 } while (!err);
1765
1766 return netdev;
1767
1768 exit:
1769 xennet_free_netdev(netdev);
1770 return ERR_PTR(err);
1771}
1772
1773/*
1774 * Entry point to this code when a new device is created. Allocate the basic
1775 * structures and the ring buffers for communication with the backend, and
1776 * inform the backend of the appropriate details for those.
1777 */
1778static int netfront_probe(struct xenbus_device *dev,
1779 const struct xenbus_device_id *id)
1780{
1781 int err;
1782 struct net_device *netdev;
1783 struct netfront_info *info;
1784
1785 netdev = xennet_create_dev(dev);
1786 if (IS_ERR(netdev)) {
1787 err = PTR_ERR(netdev);
1788 xenbus_dev_fatal(dev, err, "creating netdev");
1789 return err;
1790 }
1791
1792 info = netdev_priv(netdev);
1793 dev_set_drvdata(&dev->dev, info);
1794#ifdef CONFIG_SYSFS
1795 info->netdev->sysfs_groups[0] = &xennet_dev_group;
1796#endif
1797
1798 return 0;
1799}
1800
1801static void xennet_end_access(int ref, void *page)
1802{
1803 /* This frees the page as a side-effect */
1804 if (ref != INVALID_GRANT_REF)
1805 gnttab_end_foreign_access(ref, virt_to_page(page));
1806}
1807
1808static void xennet_disconnect_backend(struct netfront_info *info)
1809{
1810 unsigned int i = 0;
1811 unsigned int num_queues = info->netdev->real_num_tx_queues;
1812
1813 netif_carrier_off(info->netdev);
1814
1815 for (i = 0; i < num_queues && info->queues; ++i) {
1816 struct netfront_queue *queue = &info->queues[i];
1817
1818 del_timer_sync(&queue->rx_refill_timer);
1819
1820 if (queue->tx_irq && (queue->tx_irq == queue->rx_irq))
1821 unbind_from_irqhandler(queue->tx_irq, queue);
1822 if (queue->tx_irq && (queue->tx_irq != queue->rx_irq)) {
1823 unbind_from_irqhandler(queue->tx_irq, queue);
1824 unbind_from_irqhandler(queue->rx_irq, queue);
1825 }
1826 queue->tx_evtchn = queue->rx_evtchn = 0;
1827 queue->tx_irq = queue->rx_irq = 0;
1828
1829 if (netif_running(info->netdev))
1830 napi_synchronize(&queue->napi);
1831
1832 xennet_release_tx_bufs(queue);
1833 xennet_release_rx_bufs(queue);
1834 gnttab_free_grant_references(queue->gref_tx_head);
1835 gnttab_free_grant_references(queue->gref_rx_head);
1836
1837 /* End access and free the pages */
1838 xennet_end_access(queue->tx_ring_ref, queue->tx.sring);
1839 xennet_end_access(queue->rx_ring_ref, queue->rx.sring);
1840
1841 queue->tx_ring_ref = INVALID_GRANT_REF;
1842 queue->rx_ring_ref = INVALID_GRANT_REF;
1843 queue->tx.sring = NULL;
1844 queue->rx.sring = NULL;
1845
1846 page_pool_destroy(queue->page_pool);
1847 }
1848}
1849
1850/*
1851 * We are reconnecting to the backend, due to a suspend/resume, or a backend
1852 * driver restart. We tear down our netif structure and recreate it, but
1853 * leave the device-layer structures intact so that this is transparent to the
1854 * rest of the kernel.
1855 */
1856static int netfront_resume(struct xenbus_device *dev)
1857{
1858 struct netfront_info *info = dev_get_drvdata(&dev->dev);
1859
1860 dev_dbg(&dev->dev, "%s\n", dev->nodename);
1861
1862 netif_tx_lock_bh(info->netdev);
1863 netif_device_detach(info->netdev);
1864 netif_tx_unlock_bh(info->netdev);
1865
1866 xennet_disconnect_backend(info);
1867
1868 rtnl_lock();
1869 if (info->queues)
1870 xennet_destroy_queues(info);
1871 rtnl_unlock();
1872
1873 return 0;
1874}
1875
1876static int xen_net_read_mac(struct xenbus_device *dev, u8 mac[])
1877{
1878 char *s, *e, *macstr;
1879 int i;
1880
1881 macstr = s = xenbus_read(XBT_NIL, dev->nodename, "mac", NULL);
1882 if (IS_ERR(macstr))
1883 return PTR_ERR(macstr);
1884
1885 for (i = 0; i < ETH_ALEN; i++) {
1886 mac[i] = simple_strtoul(s, &e, 16);
1887 if ((s == e) || (*e != ((i == ETH_ALEN-1) ? '\0' : ':'))) {
1888 kfree(macstr);
1889 return -ENOENT;
1890 }
1891 s = e+1;
1892 }
1893
1894 kfree(macstr);
1895 return 0;
1896}
1897
1898static int setup_netfront_single(struct netfront_queue *queue)
1899{
1900 int err;
1901
1902 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->tx_evtchn);
1903 if (err < 0)
1904 goto fail;
1905
1906 err = bind_evtchn_to_irqhandler_lateeoi(queue->tx_evtchn,
1907 xennet_interrupt, 0,
1908 queue->info->netdev->name,
1909 queue);
1910 if (err < 0)
1911 goto bind_fail;
1912 queue->rx_evtchn = queue->tx_evtchn;
1913 queue->rx_irq = queue->tx_irq = err;
1914
1915 return 0;
1916
1917bind_fail:
1918 xenbus_free_evtchn(queue->info->xbdev, queue->tx_evtchn);
1919 queue->tx_evtchn = 0;
1920fail:
1921 return err;
1922}
1923
1924static int setup_netfront_split(struct netfront_queue *queue)
1925{
1926 int err;
1927
1928 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->tx_evtchn);
1929 if (err < 0)
1930 goto fail;
1931 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->rx_evtchn);
1932 if (err < 0)
1933 goto alloc_rx_evtchn_fail;
1934
1935 snprintf(queue->tx_irq_name, sizeof(queue->tx_irq_name),
1936 "%s-tx", queue->name);
1937 err = bind_evtchn_to_irqhandler_lateeoi(queue->tx_evtchn,
1938 xennet_tx_interrupt, 0,
1939 queue->tx_irq_name, queue);
1940 if (err < 0)
1941 goto bind_tx_fail;
1942 queue->tx_irq = err;
1943
1944 snprintf(queue->rx_irq_name, sizeof(queue->rx_irq_name),
1945 "%s-rx", queue->name);
1946 err = bind_evtchn_to_irqhandler_lateeoi(queue->rx_evtchn,
1947 xennet_rx_interrupt, 0,
1948 queue->rx_irq_name, queue);
1949 if (err < 0)
1950 goto bind_rx_fail;
1951 queue->rx_irq = err;
1952
1953 return 0;
1954
1955bind_rx_fail:
1956 unbind_from_irqhandler(queue->tx_irq, queue);
1957 queue->tx_irq = 0;
1958bind_tx_fail:
1959 xenbus_free_evtchn(queue->info->xbdev, queue->rx_evtchn);
1960 queue->rx_evtchn = 0;
1961alloc_rx_evtchn_fail:
1962 xenbus_free_evtchn(queue->info->xbdev, queue->tx_evtchn);
1963 queue->tx_evtchn = 0;
1964fail:
1965 return err;
1966}
1967
1968static int setup_netfront(struct xenbus_device *dev,
1969 struct netfront_queue *queue, unsigned int feature_split_evtchn)
1970{
1971 struct xen_netif_tx_sring *txs;
1972 struct xen_netif_rx_sring *rxs;
1973 int err;
1974
1975 queue->tx_ring_ref = INVALID_GRANT_REF;
1976 queue->rx_ring_ref = INVALID_GRANT_REF;
1977 queue->rx.sring = NULL;
1978 queue->tx.sring = NULL;
1979
1980 err = xenbus_setup_ring(dev, GFP_NOIO | __GFP_HIGH, (void **)&txs,
1981 1, &queue->tx_ring_ref);
1982 if (err)
1983 goto fail;
1984
1985 XEN_FRONT_RING_INIT(&queue->tx, txs, XEN_PAGE_SIZE);
1986
1987 err = xenbus_setup_ring(dev, GFP_NOIO | __GFP_HIGH, (void **)&rxs,
1988 1, &queue->rx_ring_ref);
1989 if (err)
1990 goto fail;
1991
1992 XEN_FRONT_RING_INIT(&queue->rx, rxs, XEN_PAGE_SIZE);
1993
1994 if (feature_split_evtchn)
1995 err = setup_netfront_split(queue);
1996 /* setup single event channel if
1997 * a) feature-split-event-channels == 0
1998 * b) feature-split-event-channels == 1 but failed to setup
1999 */
2000 if (!feature_split_evtchn || err)
2001 err = setup_netfront_single(queue);
2002
2003 if (err)
2004 goto fail;
2005
2006 return 0;
2007
2008 fail:
2009 xenbus_teardown_ring((void **)&queue->rx.sring, 1, &queue->rx_ring_ref);
2010 xenbus_teardown_ring((void **)&queue->tx.sring, 1, &queue->tx_ring_ref);
2011
2012 return err;
2013}
2014
2015/* Queue-specific initialisation
2016 * This used to be done in xennet_create_dev() but must now
2017 * be run per-queue.
2018 */
2019static int xennet_init_queue(struct netfront_queue *queue)
2020{
2021 unsigned short i;
2022 int err = 0;
2023 char *devid;
2024
2025 spin_lock_init(&queue->tx_lock);
2026 spin_lock_init(&queue->rx_lock);
2027 spin_lock_init(&queue->rx_cons_lock);
2028
2029 timer_setup(&queue->rx_refill_timer, rx_refill_timeout, 0);
2030
2031 devid = strrchr(queue->info->xbdev->nodename, '/') + 1;
2032 snprintf(queue->name, sizeof(queue->name), "vif%s-q%u",
2033 devid, queue->id);
2034
2035 /* Initialise tx_skb_freelist as a free chain containing every entry. */
2036 queue->tx_skb_freelist = 0;
2037 queue->tx_pend_queue = TX_LINK_NONE;
2038 for (i = 0; i < NET_TX_RING_SIZE; i++) {
2039 queue->tx_link[i] = i + 1;
2040 queue->grant_tx_ref[i] = INVALID_GRANT_REF;
2041 queue->grant_tx_page[i] = NULL;
2042 }
2043 queue->tx_link[NET_TX_RING_SIZE - 1] = TX_LINK_NONE;
2044
2045 /* Clear out rx_skbs */
2046 for (i = 0; i < NET_RX_RING_SIZE; i++) {
2047 queue->rx_skbs[i] = NULL;
2048 queue->grant_rx_ref[i] = INVALID_GRANT_REF;
2049 }
2050
2051 /* A grant for every tx ring slot */
2052 if (gnttab_alloc_grant_references(NET_TX_RING_SIZE,
2053 &queue->gref_tx_head) < 0) {
2054 pr_alert("can't alloc tx grant refs\n");
2055 err = -ENOMEM;
2056 goto exit;
2057 }
2058
2059 /* A grant for every rx ring slot */
2060 if (gnttab_alloc_grant_references(NET_RX_RING_SIZE,
2061 &queue->gref_rx_head) < 0) {
2062 pr_alert("can't alloc rx grant refs\n");
2063 err = -ENOMEM;
2064 goto exit_free_tx;
2065 }
2066
2067 return 0;
2068
2069 exit_free_tx:
2070 gnttab_free_grant_references(queue->gref_tx_head);
2071 exit:
2072 return err;
2073}
2074
2075static int write_queue_xenstore_keys(struct netfront_queue *queue,
2076 struct xenbus_transaction *xbt, int write_hierarchical)
2077{
2078 /* Write the queue-specific keys into XenStore in the traditional
2079 * way for a single queue, or in a queue subkeys for multiple
2080 * queues.
2081 */
2082 struct xenbus_device *dev = queue->info->xbdev;
2083 int err;
2084 const char *message;
2085 char *path;
2086 size_t pathsize;
2087
2088 /* Choose the correct place to write the keys */
2089 if (write_hierarchical) {
2090 pathsize = strlen(dev->nodename) + 10;
2091 path = kzalloc(pathsize, GFP_KERNEL);
2092 if (!path) {
2093 err = -ENOMEM;
2094 message = "out of memory while writing ring references";
2095 goto error;
2096 }
2097 snprintf(path, pathsize, "%s/queue-%u",
2098 dev->nodename, queue->id);
2099 } else {
2100 path = (char *)dev->nodename;
2101 }
2102
2103 /* Write ring references */
2104 err = xenbus_printf(*xbt, path, "tx-ring-ref", "%u",
2105 queue->tx_ring_ref);
2106 if (err) {
2107 message = "writing tx-ring-ref";
2108 goto error;
2109 }
2110
2111 err = xenbus_printf(*xbt, path, "rx-ring-ref", "%u",
2112 queue->rx_ring_ref);
2113 if (err) {
2114 message = "writing rx-ring-ref";
2115 goto error;
2116 }
2117
2118 /* Write event channels; taking into account both shared
2119 * and split event channel scenarios.
2120 */
2121 if (queue->tx_evtchn == queue->rx_evtchn) {
2122 /* Shared event channel */
2123 err = xenbus_printf(*xbt, path,
2124 "event-channel", "%u", queue->tx_evtchn);
2125 if (err) {
2126 message = "writing event-channel";
2127 goto error;
2128 }
2129 } else {
2130 /* Split event channels */
2131 err = xenbus_printf(*xbt, path,
2132 "event-channel-tx", "%u", queue->tx_evtchn);
2133 if (err) {
2134 message = "writing event-channel-tx";
2135 goto error;
2136 }
2137
2138 err = xenbus_printf(*xbt, path,
2139 "event-channel-rx", "%u", queue->rx_evtchn);
2140 if (err) {
2141 message = "writing event-channel-rx";
2142 goto error;
2143 }
2144 }
2145
2146 if (write_hierarchical)
2147 kfree(path);
2148 return 0;
2149
2150error:
2151 if (write_hierarchical)
2152 kfree(path);
2153 xenbus_dev_fatal(dev, err, "%s", message);
2154 return err;
2155}
2156
2157
2158
2159static int xennet_create_page_pool(struct netfront_queue *queue)
2160{
2161 int err;
2162 struct page_pool_params pp_params = {
2163 .order = 0,
2164 .flags = 0,
2165 .pool_size = NET_RX_RING_SIZE,
2166 .nid = NUMA_NO_NODE,
2167 .dev = &queue->info->netdev->dev,
2168 .offset = XDP_PACKET_HEADROOM,
2169 .max_len = XEN_PAGE_SIZE - XDP_PACKET_HEADROOM,
2170 };
2171
2172 queue->page_pool = page_pool_create(&pp_params);
2173 if (IS_ERR(queue->page_pool)) {
2174 err = PTR_ERR(queue->page_pool);
2175 queue->page_pool = NULL;
2176 return err;
2177 }
2178
2179 err = xdp_rxq_info_reg(&queue->xdp_rxq, queue->info->netdev,
2180 queue->id, 0);
2181 if (err) {
2182 netdev_err(queue->info->netdev, "xdp_rxq_info_reg failed\n");
2183 goto err_free_pp;
2184 }
2185
2186 err = xdp_rxq_info_reg_mem_model(&queue->xdp_rxq,
2187 MEM_TYPE_PAGE_POOL, queue->page_pool);
2188 if (err) {
2189 netdev_err(queue->info->netdev, "xdp_rxq_info_reg_mem_model failed\n");
2190 goto err_unregister_rxq;
2191 }
2192 return 0;
2193
2194err_unregister_rxq:
2195 xdp_rxq_info_unreg(&queue->xdp_rxq);
2196err_free_pp:
2197 page_pool_destroy(queue->page_pool);
2198 queue->page_pool = NULL;
2199 return err;
2200}
2201
2202static int xennet_create_queues(struct netfront_info *info,
2203 unsigned int *num_queues)
2204{
2205 unsigned int i;
2206 int ret;
2207
2208 info->queues = kcalloc(*num_queues, sizeof(struct netfront_queue),
2209 GFP_KERNEL);
2210 if (!info->queues)
2211 return -ENOMEM;
2212
2213 for (i = 0; i < *num_queues; i++) {
2214 struct netfront_queue *queue = &info->queues[i];
2215
2216 queue->id = i;
2217 queue->info = info;
2218
2219 ret = xennet_init_queue(queue);
2220 if (ret < 0) {
2221 dev_warn(&info->xbdev->dev,
2222 "only created %d queues\n", i);
2223 *num_queues = i;
2224 break;
2225 }
2226
2227 /* use page pool recycling instead of buddy allocator */
2228 ret = xennet_create_page_pool(queue);
2229 if (ret < 0) {
2230 dev_err(&info->xbdev->dev, "can't allocate page pool\n");
2231 *num_queues = i;
2232 return ret;
2233 }
2234
2235 netif_napi_add(queue->info->netdev, &queue->napi, xennet_poll);
2236 if (netif_running(info->netdev))
2237 napi_enable(&queue->napi);
2238 }
2239
2240 netif_set_real_num_tx_queues(info->netdev, *num_queues);
2241
2242 if (*num_queues == 0) {
2243 dev_err(&info->xbdev->dev, "no queues\n");
2244 return -EINVAL;
2245 }
2246 return 0;
2247}
2248
2249/* Common code used when first setting up, and when resuming. */
2250static int talk_to_netback(struct xenbus_device *dev,
2251 struct netfront_info *info)
2252{
2253 const char *message;
2254 struct xenbus_transaction xbt;
2255 int err;
2256 unsigned int feature_split_evtchn;
2257 unsigned int i = 0;
2258 unsigned int max_queues = 0;
2259 struct netfront_queue *queue = NULL;
2260 unsigned int num_queues = 1;
2261 u8 addr[ETH_ALEN];
2262
2263 info->netdev->irq = 0;
2264
2265 /* Check if backend is trusted. */
2266 info->bounce = !xennet_trusted ||
2267 !xenbus_read_unsigned(dev->nodename, "trusted", 1);
2268
2269 /* Check if backend supports multiple queues */
2270 max_queues = xenbus_read_unsigned(info->xbdev->otherend,
2271 "multi-queue-max-queues", 1);
2272 num_queues = min(max_queues, xennet_max_queues);
2273
2274 /* Check feature-split-event-channels */
2275 feature_split_evtchn = xenbus_read_unsigned(info->xbdev->otherend,
2276 "feature-split-event-channels", 0);
2277
2278 /* Read mac addr. */
2279 err = xen_net_read_mac(dev, addr);
2280 if (err) {
2281 xenbus_dev_fatal(dev, err, "parsing %s/mac", dev->nodename);
2282 goto out_unlocked;
2283 }
2284 eth_hw_addr_set(info->netdev, addr);
2285
2286 info->netback_has_xdp_headroom = xenbus_read_unsigned(info->xbdev->otherend,
2287 "feature-xdp-headroom", 0);
2288 if (info->netback_has_xdp_headroom) {
2289 /* set the current xen-netfront xdp state */
2290 err = talk_to_netback_xdp(info, info->netfront_xdp_enabled ?
2291 NETBACK_XDP_HEADROOM_ENABLE :
2292 NETBACK_XDP_HEADROOM_DISABLE);
2293 if (err)
2294 goto out_unlocked;
2295 }
2296
2297 rtnl_lock();
2298 if (info->queues)
2299 xennet_destroy_queues(info);
2300
2301 /* For the case of a reconnect reset the "broken" indicator. */
2302 info->broken = false;
2303
2304 err = xennet_create_queues(info, &num_queues);
2305 if (err < 0) {
2306 xenbus_dev_fatal(dev, err, "creating queues");
2307 kfree(info->queues);
2308 info->queues = NULL;
2309 goto out;
2310 }
2311 rtnl_unlock();
2312
2313 /* Create shared ring, alloc event channel -- for each queue */
2314 for (i = 0; i < num_queues; ++i) {
2315 queue = &info->queues[i];
2316 err = setup_netfront(dev, queue, feature_split_evtchn);
2317 if (err)
2318 goto destroy_ring;
2319 }
2320
2321again:
2322 err = xenbus_transaction_start(&xbt);
2323 if (err) {
2324 xenbus_dev_fatal(dev, err, "starting transaction");
2325 goto destroy_ring;
2326 }
2327
2328 if (xenbus_exists(XBT_NIL,
2329 info->xbdev->otherend, "multi-queue-max-queues")) {
2330 /* Write the number of queues */
2331 err = xenbus_printf(xbt, dev->nodename,
2332 "multi-queue-num-queues", "%u", num_queues);
2333 if (err) {
2334 message = "writing multi-queue-num-queues";
2335 goto abort_transaction_no_dev_fatal;
2336 }
2337 }
2338
2339 if (num_queues == 1) {
2340 err = write_queue_xenstore_keys(&info->queues[0], &xbt, 0); /* flat */
2341 if (err)
2342 goto abort_transaction_no_dev_fatal;
2343 } else {
2344 /* Write the keys for each queue */
2345 for (i = 0; i < num_queues; ++i) {
2346 queue = &info->queues[i];
2347 err = write_queue_xenstore_keys(queue, &xbt, 1); /* hierarchical */
2348 if (err)
2349 goto abort_transaction_no_dev_fatal;
2350 }
2351 }
2352
2353 /* The remaining keys are not queue-specific */
2354 err = xenbus_printf(xbt, dev->nodename, "request-rx-copy", "%u",
2355 1);
2356 if (err) {
2357 message = "writing request-rx-copy";
2358 goto abort_transaction;
2359 }
2360
2361 err = xenbus_printf(xbt, dev->nodename, "feature-rx-notify", "%d", 1);
2362 if (err) {
2363 message = "writing feature-rx-notify";
2364 goto abort_transaction;
2365 }
2366
2367 err = xenbus_printf(xbt, dev->nodename, "feature-sg", "%d", 1);
2368 if (err) {
2369 message = "writing feature-sg";
2370 goto abort_transaction;
2371 }
2372
2373 err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv4", "%d", 1);
2374 if (err) {
2375 message = "writing feature-gso-tcpv4";
2376 goto abort_transaction;
2377 }
2378
2379 err = xenbus_write(xbt, dev->nodename, "feature-gso-tcpv6", "1");
2380 if (err) {
2381 message = "writing feature-gso-tcpv6";
2382 goto abort_transaction;
2383 }
2384
2385 err = xenbus_write(xbt, dev->nodename, "feature-ipv6-csum-offload",
2386 "1");
2387 if (err) {
2388 message = "writing feature-ipv6-csum-offload";
2389 goto abort_transaction;
2390 }
2391
2392 err = xenbus_transaction_end(xbt, 0);
2393 if (err) {
2394 if (err == -EAGAIN)
2395 goto again;
2396 xenbus_dev_fatal(dev, err, "completing transaction");
2397 goto destroy_ring;
2398 }
2399
2400 return 0;
2401
2402 abort_transaction:
2403 xenbus_dev_fatal(dev, err, "%s", message);
2404abort_transaction_no_dev_fatal:
2405 xenbus_transaction_end(xbt, 1);
2406 destroy_ring:
2407 xennet_disconnect_backend(info);
2408 rtnl_lock();
2409 xennet_destroy_queues(info);
2410 out:
2411 rtnl_unlock();
2412out_unlocked:
2413 device_unregister(&dev->dev);
2414 return err;
2415}
2416
2417static int xennet_connect(struct net_device *dev)
2418{
2419 struct netfront_info *np = netdev_priv(dev);
2420 unsigned int num_queues = 0;
2421 int err;
2422 unsigned int j = 0;
2423 struct netfront_queue *queue = NULL;
2424
2425 if (!xenbus_read_unsigned(np->xbdev->otherend, "feature-rx-copy", 0)) {
2426 dev_info(&dev->dev,
2427 "backend does not support copying receive path\n");
2428 return -ENODEV;
2429 }
2430
2431 err = talk_to_netback(np->xbdev, np);
2432 if (err)
2433 return err;
2434 if (np->netback_has_xdp_headroom)
2435 pr_info("backend supports XDP headroom\n");
2436 if (np->bounce)
2437 dev_info(&np->xbdev->dev,
2438 "bouncing transmitted data to zeroed pages\n");
2439
2440 /* talk_to_netback() sets the correct number of queues */
2441 num_queues = dev->real_num_tx_queues;
2442
2443 if (dev->reg_state == NETREG_UNINITIALIZED) {
2444 err = register_netdev(dev);
2445 if (err) {
2446 pr_warn("%s: register_netdev err=%d\n", __func__, err);
2447 device_unregister(&np->xbdev->dev);
2448 return err;
2449 }
2450 }
2451
2452 rtnl_lock();
2453 netdev_update_features(dev);
2454 rtnl_unlock();
2455
2456 /*
2457 * All public and private state should now be sane. Get
2458 * ready to start sending and receiving packets and give the driver
2459 * domain a kick because we've probably just requeued some
2460 * packets.
2461 */
2462 netif_tx_lock_bh(np->netdev);
2463 netif_device_attach(np->netdev);
2464 netif_tx_unlock_bh(np->netdev);
2465
2466 netif_carrier_on(np->netdev);
2467 for (j = 0; j < num_queues; ++j) {
2468 queue = &np->queues[j];
2469
2470 notify_remote_via_irq(queue->tx_irq);
2471 if (queue->tx_irq != queue->rx_irq)
2472 notify_remote_via_irq(queue->rx_irq);
2473
2474 spin_lock_bh(&queue->rx_lock);
2475 xennet_alloc_rx_buffers(queue);
2476 spin_unlock_bh(&queue->rx_lock);
2477 }
2478
2479 return 0;
2480}
2481
2482/*
2483 * Callback received when the backend's state changes.
2484 */
2485static void netback_changed(struct xenbus_device *dev,
2486 enum xenbus_state backend_state)
2487{
2488 struct netfront_info *np = dev_get_drvdata(&dev->dev);
2489 struct net_device *netdev = np->netdev;
2490
2491 dev_dbg(&dev->dev, "%s\n", xenbus_strstate(backend_state));
2492
2493 wake_up_all(&module_wq);
2494
2495 switch (backend_state) {
2496 case XenbusStateInitialising:
2497 case XenbusStateInitialised:
2498 case XenbusStateReconfiguring:
2499 case XenbusStateReconfigured:
2500 case XenbusStateUnknown:
2501 break;
2502
2503 case XenbusStateInitWait:
2504 if (dev->state != XenbusStateInitialising)
2505 break;
2506 if (xennet_connect(netdev) != 0)
2507 break;
2508 xenbus_switch_state(dev, XenbusStateConnected);
2509 break;
2510
2511 case XenbusStateConnected:
2512 netdev_notify_peers(netdev);
2513 break;
2514
2515 case XenbusStateClosed:
2516 if (dev->state == XenbusStateClosed)
2517 break;
2518 fallthrough; /* Missed the backend's CLOSING state */
2519 case XenbusStateClosing:
2520 xenbus_frontend_closed(dev);
2521 break;
2522 }
2523}
2524
2525static const struct xennet_stat {
2526 char name[ETH_GSTRING_LEN];
2527 u16 offset;
2528} xennet_stats[] = {
2529 {
2530 "rx_gso_checksum_fixup",
2531 offsetof(struct netfront_info, rx_gso_checksum_fixup)
2532 },
2533};
2534
2535static int xennet_get_sset_count(struct net_device *dev, int string_set)
2536{
2537 switch (string_set) {
2538 case ETH_SS_STATS:
2539 return ARRAY_SIZE(xennet_stats);
2540 default:
2541 return -EINVAL;
2542 }
2543}
2544
2545static void xennet_get_ethtool_stats(struct net_device *dev,
2546 struct ethtool_stats *stats, u64 * data)
2547{
2548 void *np = netdev_priv(dev);
2549 int i;
2550
2551 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++)
2552 data[i] = atomic_read((atomic_t *)(np + xennet_stats[i].offset));
2553}
2554
2555static void xennet_get_strings(struct net_device *dev, u32 stringset, u8 * data)
2556{
2557 int i;
2558
2559 switch (stringset) {
2560 case ETH_SS_STATS:
2561 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++)
2562 memcpy(data + i * ETH_GSTRING_LEN,
2563 xennet_stats[i].name, ETH_GSTRING_LEN);
2564 break;
2565 }
2566}
2567
2568static const struct ethtool_ops xennet_ethtool_ops =
2569{
2570 .get_link = ethtool_op_get_link,
2571
2572 .get_sset_count = xennet_get_sset_count,
2573 .get_ethtool_stats = xennet_get_ethtool_stats,
2574 .get_strings = xennet_get_strings,
2575 .get_ts_info = ethtool_op_get_ts_info,
2576};
2577
2578#ifdef CONFIG_SYSFS
2579static ssize_t show_rxbuf(struct device *dev,
2580 struct device_attribute *attr, char *buf)
2581{
2582 return sprintf(buf, "%lu\n", NET_RX_RING_SIZE);
2583}
2584
2585static ssize_t store_rxbuf(struct device *dev,
2586 struct device_attribute *attr,
2587 const char *buf, size_t len)
2588{
2589 char *endp;
2590
2591 if (!capable(CAP_NET_ADMIN))
2592 return -EPERM;
2593
2594 simple_strtoul(buf, &endp, 0);
2595 if (endp == buf)
2596 return -EBADMSG;
2597
2598 /* rxbuf_min and rxbuf_max are no longer configurable. */
2599
2600 return len;
2601}
2602
2603static DEVICE_ATTR(rxbuf_min, 0644, show_rxbuf, store_rxbuf);
2604static DEVICE_ATTR(rxbuf_max, 0644, show_rxbuf, store_rxbuf);
2605static DEVICE_ATTR(rxbuf_cur, 0444, show_rxbuf, NULL);
2606
2607static struct attribute *xennet_dev_attrs[] = {
2608 &dev_attr_rxbuf_min.attr,
2609 &dev_attr_rxbuf_max.attr,
2610 &dev_attr_rxbuf_cur.attr,
2611 NULL
2612};
2613
2614static const struct attribute_group xennet_dev_group = {
2615 .attrs = xennet_dev_attrs
2616};
2617#endif /* CONFIG_SYSFS */
2618
2619static void xennet_bus_close(struct xenbus_device *dev)
2620{
2621 int ret;
2622
2623 if (xenbus_read_driver_state(dev->otherend) == XenbusStateClosed)
2624 return;
2625 do {
2626 xenbus_switch_state(dev, XenbusStateClosing);
2627 ret = wait_event_timeout(module_wq,
2628 xenbus_read_driver_state(dev->otherend) ==
2629 XenbusStateClosing ||
2630 xenbus_read_driver_state(dev->otherend) ==
2631 XenbusStateClosed ||
2632 xenbus_read_driver_state(dev->otherend) ==
2633 XenbusStateUnknown,
2634 XENNET_TIMEOUT);
2635 } while (!ret);
2636
2637 if (xenbus_read_driver_state(dev->otherend) == XenbusStateClosed)
2638 return;
2639
2640 do {
2641 xenbus_switch_state(dev, XenbusStateClosed);
2642 ret = wait_event_timeout(module_wq,
2643 xenbus_read_driver_state(dev->otherend) ==
2644 XenbusStateClosed ||
2645 xenbus_read_driver_state(dev->otherend) ==
2646 XenbusStateUnknown,
2647 XENNET_TIMEOUT);
2648 } while (!ret);
2649}
2650
2651static void xennet_remove(struct xenbus_device *dev)
2652{
2653 struct netfront_info *info = dev_get_drvdata(&dev->dev);
2654
2655 xennet_bus_close(dev);
2656 xennet_disconnect_backend(info);
2657
2658 if (info->netdev->reg_state == NETREG_REGISTERED)
2659 unregister_netdev(info->netdev);
2660
2661 if (info->queues) {
2662 rtnl_lock();
2663 xennet_destroy_queues(info);
2664 rtnl_unlock();
2665 }
2666 xennet_free_netdev(info->netdev);
2667}
2668
2669static const struct xenbus_device_id netfront_ids[] = {
2670 { "vif" },
2671 { "" }
2672};
2673
2674static struct xenbus_driver netfront_driver = {
2675 .ids = netfront_ids,
2676 .probe = netfront_probe,
2677 .remove = xennet_remove,
2678 .resume = netfront_resume,
2679 .otherend_changed = netback_changed,
2680};
2681
2682static int __init netif_init(void)
2683{
2684 if (!xen_domain())
2685 return -ENODEV;
2686
2687 if (!xen_has_pv_nic_devices())
2688 return -ENODEV;
2689
2690 pr_info("Initialising Xen virtual ethernet driver\n");
2691
2692 /* Allow as many queues as there are CPUs inut max. 8 if user has not
2693 * specified a value.
2694 */
2695 if (xennet_max_queues == 0)
2696 xennet_max_queues = min_t(unsigned int, MAX_QUEUES_DEFAULT,
2697 num_online_cpus());
2698
2699 return xenbus_register_frontend(&netfront_driver);
2700}
2701module_init(netif_init);
2702
2703
2704static void __exit netif_exit(void)
2705{
2706 xenbus_unregister_driver(&netfront_driver);
2707}
2708module_exit(netif_exit);
2709
2710MODULE_DESCRIPTION("Xen virtual network device frontend");
2711MODULE_LICENSE("GPL");
2712MODULE_ALIAS("xen:vif");
2713MODULE_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
48#include <xen/xen.h>
49#include <xen/xenbus.h>
50#include <xen/events.h>
51#include <xen/page.h>
52#include <xen/platform_pci.h>
53#include <xen/grant_table.h>
54
55#include <xen/interface/io/netif.h>
56#include <xen/interface/memory.h>
57#include <xen/interface/grant_table.h>
58
59/* Module parameters */
60#define MAX_QUEUES_DEFAULT 8
61static unsigned int xennet_max_queues;
62module_param_named(max_queues, xennet_max_queues, uint, 0644);
63MODULE_PARM_DESC(max_queues,
64 "Maximum number of queues per virtual interface");
65
66static const struct ethtool_ops xennet_ethtool_ops;
67
68struct netfront_cb {
69 int pull_to;
70};
71
72#define NETFRONT_SKB_CB(skb) ((struct netfront_cb *)((skb)->cb))
73
74#define RX_COPY_THRESHOLD 256
75
76#define GRANT_INVALID_REF 0
77
78#define NET_TX_RING_SIZE __CONST_RING_SIZE(xen_netif_tx, XEN_PAGE_SIZE)
79#define NET_RX_RING_SIZE __CONST_RING_SIZE(xen_netif_rx, XEN_PAGE_SIZE)
80
81/* Minimum number of Rx slots (includes slot for GSO metadata). */
82#define NET_RX_SLOTS_MIN (XEN_NETIF_NR_SLOTS_MIN + 1)
83
84/* Queue name is interface name with "-qNNN" appended */
85#define QUEUE_NAME_SIZE (IFNAMSIZ + 6)
86
87/* IRQ name is queue name with "-tx" or "-rx" appended */
88#define IRQ_NAME_SIZE (QUEUE_NAME_SIZE + 3)
89
90static DECLARE_WAIT_QUEUE_HEAD(module_unload_q);
91
92struct netfront_stats {
93 u64 packets;
94 u64 bytes;
95 struct u64_stats_sync syncp;
96};
97
98struct netfront_info;
99
100struct netfront_queue {
101 unsigned int id; /* Queue ID, 0-based */
102 char name[QUEUE_NAME_SIZE]; /* DEVNAME-qN */
103 struct netfront_info *info;
104
105 struct napi_struct napi;
106
107 /* Split event channels support, tx_* == rx_* when using
108 * single event channel.
109 */
110 unsigned int tx_evtchn, rx_evtchn;
111 unsigned int tx_irq, rx_irq;
112 /* Only used when split event channels support is enabled */
113 char tx_irq_name[IRQ_NAME_SIZE]; /* DEVNAME-qN-tx */
114 char rx_irq_name[IRQ_NAME_SIZE]; /* DEVNAME-qN-rx */
115
116 spinlock_t tx_lock;
117 struct xen_netif_tx_front_ring tx;
118 int tx_ring_ref;
119
120 /*
121 * {tx,rx}_skbs store outstanding skbuffs. Free tx_skb entries
122 * are linked from tx_skb_freelist through skb_entry.link.
123 *
124 * NB. Freelist index entries are always going to be less than
125 * PAGE_OFFSET, whereas pointers to skbs will always be equal or
126 * greater than PAGE_OFFSET: we use this property to distinguish
127 * them.
128 */
129 union skb_entry {
130 struct sk_buff *skb;
131 unsigned long link;
132 } tx_skbs[NET_TX_RING_SIZE];
133 grant_ref_t gref_tx_head;
134 grant_ref_t grant_tx_ref[NET_TX_RING_SIZE];
135 struct page *grant_tx_page[NET_TX_RING_SIZE];
136 unsigned tx_skb_freelist;
137
138 spinlock_t rx_lock ____cacheline_aligned_in_smp;
139 struct xen_netif_rx_front_ring rx;
140 int rx_ring_ref;
141
142 struct timer_list rx_refill_timer;
143
144 struct sk_buff *rx_skbs[NET_RX_RING_SIZE];
145 grant_ref_t gref_rx_head;
146 grant_ref_t grant_rx_ref[NET_RX_RING_SIZE];
147};
148
149struct netfront_info {
150 struct list_head list;
151 struct net_device *netdev;
152
153 struct xenbus_device *xbdev;
154
155 /* Multi-queue support */
156 struct netfront_queue *queues;
157
158 /* Statistics */
159 struct netfront_stats __percpu *rx_stats;
160 struct netfront_stats __percpu *tx_stats;
161
162 atomic_t rx_gso_checksum_fixup;
163};
164
165struct netfront_rx_info {
166 struct xen_netif_rx_response rx;
167 struct xen_netif_extra_info extras[XEN_NETIF_EXTRA_TYPE_MAX - 1];
168};
169
170static void skb_entry_set_link(union skb_entry *list, unsigned short id)
171{
172 list->link = id;
173}
174
175static int skb_entry_is_link(const union skb_entry *list)
176{
177 BUILD_BUG_ON(sizeof(list->skb) != sizeof(list->link));
178 return (unsigned long)list->skb < PAGE_OFFSET;
179}
180
181/*
182 * Access macros for acquiring freeing slots in tx_skbs[].
183 */
184
185static void add_id_to_freelist(unsigned *head, union skb_entry *list,
186 unsigned short id)
187{
188 skb_entry_set_link(&list[id], *head);
189 *head = id;
190}
191
192static unsigned short get_id_from_freelist(unsigned *head,
193 union skb_entry *list)
194{
195 unsigned int id = *head;
196 *head = list[id].link;
197 return id;
198}
199
200static int xennet_rxidx(RING_IDX idx)
201{
202 return idx & (NET_RX_RING_SIZE - 1);
203}
204
205static struct sk_buff *xennet_get_rx_skb(struct netfront_queue *queue,
206 RING_IDX ri)
207{
208 int i = xennet_rxidx(ri);
209 struct sk_buff *skb = queue->rx_skbs[i];
210 queue->rx_skbs[i] = NULL;
211 return skb;
212}
213
214static grant_ref_t xennet_get_rx_ref(struct netfront_queue *queue,
215 RING_IDX ri)
216{
217 int i = xennet_rxidx(ri);
218 grant_ref_t ref = queue->grant_rx_ref[i];
219 queue->grant_rx_ref[i] = GRANT_INVALID_REF;
220 return ref;
221}
222
223#ifdef CONFIG_SYSFS
224static const struct attribute_group xennet_dev_group;
225#endif
226
227static bool xennet_can_sg(struct net_device *dev)
228{
229 return dev->features & NETIF_F_SG;
230}
231
232
233static void rx_refill_timeout(struct timer_list *t)
234{
235 struct netfront_queue *queue = from_timer(queue, t, rx_refill_timer);
236 napi_schedule(&queue->napi);
237}
238
239static int netfront_tx_slot_available(struct netfront_queue *queue)
240{
241 return (queue->tx.req_prod_pvt - queue->tx.rsp_cons) <
242 (NET_TX_RING_SIZE - MAX_SKB_FRAGS - 2);
243}
244
245static void xennet_maybe_wake_tx(struct netfront_queue *queue)
246{
247 struct net_device *dev = queue->info->netdev;
248 struct netdev_queue *dev_queue = netdev_get_tx_queue(dev, queue->id);
249
250 if (unlikely(netif_tx_queue_stopped(dev_queue)) &&
251 netfront_tx_slot_available(queue) &&
252 likely(netif_running(dev)))
253 netif_tx_wake_queue(netdev_get_tx_queue(dev, queue->id));
254}
255
256
257static struct sk_buff *xennet_alloc_one_rx_buffer(struct netfront_queue *queue)
258{
259 struct sk_buff *skb;
260 struct page *page;
261
262 skb = __netdev_alloc_skb(queue->info->netdev,
263 RX_COPY_THRESHOLD + NET_IP_ALIGN,
264 GFP_ATOMIC | __GFP_NOWARN);
265 if (unlikely(!skb))
266 return NULL;
267
268 page = alloc_page(GFP_ATOMIC | __GFP_NOWARN);
269 if (!page) {
270 kfree_skb(skb);
271 return NULL;
272 }
273 skb_add_rx_frag(skb, 0, page, 0, 0, PAGE_SIZE);
274
275 /* Align ip header to a 16 bytes boundary */
276 skb_reserve(skb, NET_IP_ALIGN);
277 skb->dev = queue->info->netdev;
278
279 return skb;
280}
281
282
283static void xennet_alloc_rx_buffers(struct netfront_queue *queue)
284{
285 RING_IDX req_prod = queue->rx.req_prod_pvt;
286 int notify;
287 int err = 0;
288
289 if (unlikely(!netif_carrier_ok(queue->info->netdev)))
290 return;
291
292 for (req_prod = queue->rx.req_prod_pvt;
293 req_prod - queue->rx.rsp_cons < NET_RX_RING_SIZE;
294 req_prod++) {
295 struct sk_buff *skb;
296 unsigned short id;
297 grant_ref_t ref;
298 struct page *page;
299 struct xen_netif_rx_request *req;
300
301 skb = xennet_alloc_one_rx_buffer(queue);
302 if (!skb) {
303 err = -ENOMEM;
304 break;
305 }
306
307 id = xennet_rxidx(req_prod);
308
309 BUG_ON(queue->rx_skbs[id]);
310 queue->rx_skbs[id] = skb;
311
312 ref = gnttab_claim_grant_reference(&queue->gref_rx_head);
313 WARN_ON_ONCE(IS_ERR_VALUE((unsigned long)(int)ref));
314 queue->grant_rx_ref[id] = ref;
315
316 page = skb_frag_page(&skb_shinfo(skb)->frags[0]);
317
318 req = RING_GET_REQUEST(&queue->rx, req_prod);
319 gnttab_page_grant_foreign_access_ref_one(ref,
320 queue->info->xbdev->otherend_id,
321 page,
322 0);
323 req->id = id;
324 req->gref = ref;
325 }
326
327 queue->rx.req_prod_pvt = req_prod;
328
329 /* Try again later if there are not enough requests or skb allocation
330 * failed.
331 * Enough requests is quantified as the sum of newly created slots and
332 * the unconsumed slots at the backend.
333 */
334 if (req_prod - queue->rx.rsp_cons < NET_RX_SLOTS_MIN ||
335 unlikely(err)) {
336 mod_timer(&queue->rx_refill_timer, jiffies + (HZ/10));
337 return;
338 }
339
340 wmb(); /* barrier so backend seens requests */
341
342 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->rx, notify);
343 if (notify)
344 notify_remote_via_irq(queue->rx_irq);
345}
346
347static int xennet_open(struct net_device *dev)
348{
349 struct netfront_info *np = netdev_priv(dev);
350 unsigned int num_queues = dev->real_num_tx_queues;
351 unsigned int i = 0;
352 struct netfront_queue *queue = NULL;
353
354 if (!np->queues)
355 return -ENODEV;
356
357 for (i = 0; i < num_queues; ++i) {
358 queue = &np->queues[i];
359 napi_enable(&queue->napi);
360
361 spin_lock_bh(&queue->rx_lock);
362 if (netif_carrier_ok(dev)) {
363 xennet_alloc_rx_buffers(queue);
364 queue->rx.sring->rsp_event = queue->rx.rsp_cons + 1;
365 if (RING_HAS_UNCONSUMED_RESPONSES(&queue->rx))
366 napi_schedule(&queue->napi);
367 }
368 spin_unlock_bh(&queue->rx_lock);
369 }
370
371 netif_tx_start_all_queues(dev);
372
373 return 0;
374}
375
376static void xennet_tx_buf_gc(struct netfront_queue *queue)
377{
378 RING_IDX cons, prod;
379 unsigned short id;
380 struct sk_buff *skb;
381 bool more_to_do;
382
383 BUG_ON(!netif_carrier_ok(queue->info->netdev));
384
385 do {
386 prod = queue->tx.sring->rsp_prod;
387 rmb(); /* Ensure we see responses up to 'rp'. */
388
389 for (cons = queue->tx.rsp_cons; cons != prod; cons++) {
390 struct xen_netif_tx_response *txrsp;
391
392 txrsp = RING_GET_RESPONSE(&queue->tx, cons);
393 if (txrsp->status == XEN_NETIF_RSP_NULL)
394 continue;
395
396 id = txrsp->id;
397 skb = queue->tx_skbs[id].skb;
398 if (unlikely(gnttab_query_foreign_access(
399 queue->grant_tx_ref[id]) != 0)) {
400 pr_alert("%s: warning -- grant still in use by backend domain\n",
401 __func__);
402 BUG();
403 }
404 gnttab_end_foreign_access_ref(
405 queue->grant_tx_ref[id], GNTMAP_readonly);
406 gnttab_release_grant_reference(
407 &queue->gref_tx_head, queue->grant_tx_ref[id]);
408 queue->grant_tx_ref[id] = GRANT_INVALID_REF;
409 queue->grant_tx_page[id] = NULL;
410 add_id_to_freelist(&queue->tx_skb_freelist, queue->tx_skbs, id);
411 dev_kfree_skb_irq(skb);
412 }
413
414 queue->tx.rsp_cons = prod;
415
416 RING_FINAL_CHECK_FOR_RESPONSES(&queue->tx, more_to_do);
417 } while (more_to_do);
418
419 xennet_maybe_wake_tx(queue);
420}
421
422struct xennet_gnttab_make_txreq {
423 struct netfront_queue *queue;
424 struct sk_buff *skb;
425 struct page *page;
426 struct xen_netif_tx_request *tx; /* Last request */
427 unsigned int size;
428};
429
430static void xennet_tx_setup_grant(unsigned long gfn, unsigned int offset,
431 unsigned int len, void *data)
432{
433 struct xennet_gnttab_make_txreq *info = data;
434 unsigned int id;
435 struct xen_netif_tx_request *tx;
436 grant_ref_t ref;
437 /* convenient aliases */
438 struct page *page = info->page;
439 struct netfront_queue *queue = info->queue;
440 struct sk_buff *skb = info->skb;
441
442 id = get_id_from_freelist(&queue->tx_skb_freelist, queue->tx_skbs);
443 tx = RING_GET_REQUEST(&queue->tx, queue->tx.req_prod_pvt++);
444 ref = gnttab_claim_grant_reference(&queue->gref_tx_head);
445 WARN_ON_ONCE(IS_ERR_VALUE((unsigned long)(int)ref));
446
447 gnttab_grant_foreign_access_ref(ref, queue->info->xbdev->otherend_id,
448 gfn, GNTMAP_readonly);
449
450 queue->tx_skbs[id].skb = skb;
451 queue->grant_tx_page[id] = page;
452 queue->grant_tx_ref[id] = ref;
453
454 tx->id = id;
455 tx->gref = ref;
456 tx->offset = offset;
457 tx->size = len;
458 tx->flags = 0;
459
460 info->tx = tx;
461 info->size += tx->size;
462}
463
464static struct xen_netif_tx_request *xennet_make_first_txreq(
465 struct netfront_queue *queue, struct sk_buff *skb,
466 struct page *page, unsigned int offset, unsigned int len)
467{
468 struct xennet_gnttab_make_txreq info = {
469 .queue = queue,
470 .skb = skb,
471 .page = page,
472 .size = 0,
473 };
474
475 gnttab_for_one_grant(page, offset, len, xennet_tx_setup_grant, &info);
476
477 return info.tx;
478}
479
480static void xennet_make_one_txreq(unsigned long gfn, unsigned int offset,
481 unsigned int len, void *data)
482{
483 struct xennet_gnttab_make_txreq *info = data;
484
485 info->tx->flags |= XEN_NETTXF_more_data;
486 skb_get(info->skb);
487 xennet_tx_setup_grant(gfn, offset, len, data);
488}
489
490static struct xen_netif_tx_request *xennet_make_txreqs(
491 struct netfront_queue *queue, struct xen_netif_tx_request *tx,
492 struct sk_buff *skb, struct page *page,
493 unsigned int offset, unsigned int len)
494{
495 struct xennet_gnttab_make_txreq info = {
496 .queue = queue,
497 .skb = skb,
498 .tx = tx,
499 };
500
501 /* Skip unused frames from start of page */
502 page += offset >> PAGE_SHIFT;
503 offset &= ~PAGE_MASK;
504
505 while (len) {
506 info.page = page;
507 info.size = 0;
508
509 gnttab_foreach_grant_in_range(page, offset, len,
510 xennet_make_one_txreq,
511 &info);
512
513 page++;
514 offset = 0;
515 len -= info.size;
516 }
517
518 return info.tx;
519}
520
521/*
522 * Count how many ring slots are required to send this skb. Each frag
523 * might be a compound page.
524 */
525static int xennet_count_skb_slots(struct sk_buff *skb)
526{
527 int i, frags = skb_shinfo(skb)->nr_frags;
528 int slots;
529
530 slots = gnttab_count_grant(offset_in_page(skb->data),
531 skb_headlen(skb));
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 slots += gnttab_count_grant(offset, size);
542 }
543
544 return slots;
545}
546
547static u16 xennet_select_queue(struct net_device *dev, struct sk_buff *skb,
548 void *accel_priv, select_queue_fallback_t fallback)
549{
550 unsigned int num_queues = dev->real_num_tx_queues;
551 u32 hash;
552 u16 queue_idx;
553
554 /* First, check if there is only one queue */
555 if (num_queues == 1) {
556 queue_idx = 0;
557 } else {
558 hash = skb_get_hash(skb);
559 queue_idx = hash % num_queues;
560 }
561
562 return queue_idx;
563}
564
565#define MAX_XEN_SKB_FRAGS (65536 / XEN_PAGE_SIZE + 1)
566
567static int xennet_start_xmit(struct sk_buff *skb, struct net_device *dev)
568{
569 struct netfront_info *np = netdev_priv(dev);
570 struct netfront_stats *tx_stats = this_cpu_ptr(np->tx_stats);
571 struct xen_netif_tx_request *tx, *first_tx;
572 unsigned int i;
573 int notify;
574 int slots;
575 struct page *page;
576 unsigned int offset;
577 unsigned int len;
578 unsigned long flags;
579 struct netfront_queue *queue = NULL;
580 unsigned int num_queues = dev->real_num_tx_queues;
581 u16 queue_index;
582 struct sk_buff *nskb;
583
584 /* Drop the packet if no queues are set up */
585 if (num_queues < 1)
586 goto drop;
587 /* Determine which queue to transmit this SKB on */
588 queue_index = skb_get_queue_mapping(skb);
589 queue = &np->queues[queue_index];
590
591 /* If skb->len is too big for wire format, drop skb and alert
592 * user about misconfiguration.
593 */
594 if (unlikely(skb->len > XEN_NETIF_MAX_TX_SIZE)) {
595 net_alert_ratelimited(
596 "xennet: skb->len = %u, too big for wire format\n",
597 skb->len);
598 goto drop;
599 }
600
601 slots = xennet_count_skb_slots(skb);
602 if (unlikely(slots > MAX_XEN_SKB_FRAGS + 1)) {
603 net_dbg_ratelimited("xennet: skb rides the rocket: %d slots, %d bytes\n",
604 slots, skb->len);
605 if (skb_linearize(skb))
606 goto drop;
607 }
608
609 page = virt_to_page(skb->data);
610 offset = offset_in_page(skb->data);
611
612 /* The first req should be at least ETH_HLEN size or the packet will be
613 * dropped by netback.
614 */
615 if (unlikely(PAGE_SIZE - offset < ETH_HLEN)) {
616 nskb = skb_copy(skb, GFP_ATOMIC);
617 if (!nskb)
618 goto drop;
619 dev_consume_skb_any(skb);
620 skb = nskb;
621 page = virt_to_page(skb->data);
622 offset = offset_in_page(skb->data);
623 }
624
625 len = skb_headlen(skb);
626
627 spin_lock_irqsave(&queue->tx_lock, flags);
628
629 if (unlikely(!netif_carrier_ok(dev) ||
630 (slots > 1 && !xennet_can_sg(dev)) ||
631 netif_needs_gso(skb, netif_skb_features(skb)))) {
632 spin_unlock_irqrestore(&queue->tx_lock, flags);
633 goto drop;
634 }
635
636 /* First request for the linear area. */
637 first_tx = tx = xennet_make_first_txreq(queue, skb,
638 page, offset, len);
639 offset += tx->size;
640 if (offset == PAGE_SIZE) {
641 page++;
642 offset = 0;
643 }
644 len -= tx->size;
645
646 if (skb->ip_summed == CHECKSUM_PARTIAL)
647 /* local packet? */
648 tx->flags |= XEN_NETTXF_csum_blank | XEN_NETTXF_data_validated;
649 else if (skb->ip_summed == CHECKSUM_UNNECESSARY)
650 /* remote but checksummed. */
651 tx->flags |= XEN_NETTXF_data_validated;
652
653 /* Optional extra info after the first request. */
654 if (skb_shinfo(skb)->gso_size) {
655 struct xen_netif_extra_info *gso;
656
657 gso = (struct xen_netif_extra_info *)
658 RING_GET_REQUEST(&queue->tx, queue->tx.req_prod_pvt++);
659
660 tx->flags |= XEN_NETTXF_extra_info;
661
662 gso->u.gso.size = skb_shinfo(skb)->gso_size;
663 gso->u.gso.type = (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6) ?
664 XEN_NETIF_GSO_TYPE_TCPV6 :
665 XEN_NETIF_GSO_TYPE_TCPV4;
666 gso->u.gso.pad = 0;
667 gso->u.gso.features = 0;
668
669 gso->type = XEN_NETIF_EXTRA_TYPE_GSO;
670 gso->flags = 0;
671 }
672
673 /* Requests for the rest of the linear area. */
674 tx = xennet_make_txreqs(queue, tx, skb, page, offset, len);
675
676 /* Requests for all the frags. */
677 for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
678 skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
679 tx = xennet_make_txreqs(queue, tx, skb,
680 skb_frag_page(frag), frag->page_offset,
681 skb_frag_size(frag));
682 }
683
684 /* First request has the packet length. */
685 first_tx->size = skb->len;
686
687 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->tx, notify);
688 if (notify)
689 notify_remote_via_irq(queue->tx_irq);
690
691 u64_stats_update_begin(&tx_stats->syncp);
692 tx_stats->bytes += skb->len;
693 tx_stats->packets++;
694 u64_stats_update_end(&tx_stats->syncp);
695
696 /* Note: It is not safe to access skb after xennet_tx_buf_gc()! */
697 xennet_tx_buf_gc(queue);
698
699 if (!netfront_tx_slot_available(queue))
700 netif_tx_stop_queue(netdev_get_tx_queue(dev, queue->id));
701
702 spin_unlock_irqrestore(&queue->tx_lock, flags);
703
704 return NETDEV_TX_OK;
705
706 drop:
707 dev->stats.tx_dropped++;
708 dev_kfree_skb_any(skb);
709 return NETDEV_TX_OK;
710}
711
712static int xennet_close(struct net_device *dev)
713{
714 struct netfront_info *np = netdev_priv(dev);
715 unsigned int num_queues = dev->real_num_tx_queues;
716 unsigned int i;
717 struct netfront_queue *queue;
718 netif_tx_stop_all_queues(np->netdev);
719 for (i = 0; i < num_queues; ++i) {
720 queue = &np->queues[i];
721 napi_disable(&queue->napi);
722 }
723 return 0;
724}
725
726static void xennet_move_rx_slot(struct netfront_queue *queue, struct sk_buff *skb,
727 grant_ref_t ref)
728{
729 int new = xennet_rxidx(queue->rx.req_prod_pvt);
730
731 BUG_ON(queue->rx_skbs[new]);
732 queue->rx_skbs[new] = skb;
733 queue->grant_rx_ref[new] = ref;
734 RING_GET_REQUEST(&queue->rx, queue->rx.req_prod_pvt)->id = new;
735 RING_GET_REQUEST(&queue->rx, queue->rx.req_prod_pvt)->gref = ref;
736 queue->rx.req_prod_pvt++;
737}
738
739static int xennet_get_extras(struct netfront_queue *queue,
740 struct xen_netif_extra_info *extras,
741 RING_IDX rp)
742
743{
744 struct xen_netif_extra_info *extra;
745 struct device *dev = &queue->info->netdev->dev;
746 RING_IDX cons = queue->rx.rsp_cons;
747 int err = 0;
748
749 do {
750 struct sk_buff *skb;
751 grant_ref_t ref;
752
753 if (unlikely(cons + 1 == rp)) {
754 if (net_ratelimit())
755 dev_warn(dev, "Missing extra info\n");
756 err = -EBADR;
757 break;
758 }
759
760 extra = (struct xen_netif_extra_info *)
761 RING_GET_RESPONSE(&queue->rx, ++cons);
762
763 if (unlikely(!extra->type ||
764 extra->type >= XEN_NETIF_EXTRA_TYPE_MAX)) {
765 if (net_ratelimit())
766 dev_warn(dev, "Invalid extra type: %d\n",
767 extra->type);
768 err = -EINVAL;
769 } else {
770 memcpy(&extras[extra->type - 1], extra,
771 sizeof(*extra));
772 }
773
774 skb = xennet_get_rx_skb(queue, cons);
775 ref = xennet_get_rx_ref(queue, cons);
776 xennet_move_rx_slot(queue, skb, ref);
777 } while (extra->flags & XEN_NETIF_EXTRA_FLAG_MORE);
778
779 queue->rx.rsp_cons = cons;
780 return err;
781}
782
783static int xennet_get_responses(struct netfront_queue *queue,
784 struct netfront_rx_info *rinfo, RING_IDX rp,
785 struct sk_buff_head *list)
786{
787 struct xen_netif_rx_response *rx = &rinfo->rx;
788 struct xen_netif_extra_info *extras = rinfo->extras;
789 struct device *dev = &queue->info->netdev->dev;
790 RING_IDX cons = queue->rx.rsp_cons;
791 struct sk_buff *skb = xennet_get_rx_skb(queue, cons);
792 grant_ref_t ref = xennet_get_rx_ref(queue, cons);
793 int max = MAX_SKB_FRAGS + (rx->status <= RX_COPY_THRESHOLD);
794 int slots = 1;
795 int err = 0;
796 unsigned long ret;
797
798 if (rx->flags & XEN_NETRXF_extra_info) {
799 err = xennet_get_extras(queue, extras, rp);
800 cons = queue->rx.rsp_cons;
801 }
802
803 for (;;) {
804 if (unlikely(rx->status < 0 ||
805 rx->offset + rx->status > XEN_PAGE_SIZE)) {
806 if (net_ratelimit())
807 dev_warn(dev, "rx->offset: %u, size: %d\n",
808 rx->offset, rx->status);
809 xennet_move_rx_slot(queue, skb, ref);
810 err = -EINVAL;
811 goto next;
812 }
813
814 /*
815 * This definitely indicates a bug, either in this driver or in
816 * the backend driver. In future this should flag the bad
817 * situation to the system controller to reboot the backend.
818 */
819 if (ref == GRANT_INVALID_REF) {
820 if (net_ratelimit())
821 dev_warn(dev, "Bad rx response id %d.\n",
822 rx->id);
823 err = -EINVAL;
824 goto next;
825 }
826
827 ret = gnttab_end_foreign_access_ref(ref, 0);
828 BUG_ON(!ret);
829
830 gnttab_release_grant_reference(&queue->gref_rx_head, ref);
831
832 __skb_queue_tail(list, skb);
833
834next:
835 if (!(rx->flags & XEN_NETRXF_more_data))
836 break;
837
838 if (cons + slots == rp) {
839 if (net_ratelimit())
840 dev_warn(dev, "Need more slots\n");
841 err = -ENOENT;
842 break;
843 }
844
845 rx = RING_GET_RESPONSE(&queue->rx, cons + slots);
846 skb = xennet_get_rx_skb(queue, cons + slots);
847 ref = xennet_get_rx_ref(queue, cons + slots);
848 slots++;
849 }
850
851 if (unlikely(slots > max)) {
852 if (net_ratelimit())
853 dev_warn(dev, "Too many slots\n");
854 err = -E2BIG;
855 }
856
857 if (unlikely(err))
858 queue->rx.rsp_cons = cons + slots;
859
860 return err;
861}
862
863static int xennet_set_skb_gso(struct sk_buff *skb,
864 struct xen_netif_extra_info *gso)
865{
866 if (!gso->u.gso.size) {
867 if (net_ratelimit())
868 pr_warn("GSO size must not be zero\n");
869 return -EINVAL;
870 }
871
872 if (gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV4 &&
873 gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV6) {
874 if (net_ratelimit())
875 pr_warn("Bad GSO type %d\n", gso->u.gso.type);
876 return -EINVAL;
877 }
878
879 skb_shinfo(skb)->gso_size = gso->u.gso.size;
880 skb_shinfo(skb)->gso_type =
881 (gso->u.gso.type == XEN_NETIF_GSO_TYPE_TCPV4) ?
882 SKB_GSO_TCPV4 :
883 SKB_GSO_TCPV6;
884
885 /* Header must be checked, and gso_segs computed. */
886 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
887 skb_shinfo(skb)->gso_segs = 0;
888
889 return 0;
890}
891
892static RING_IDX xennet_fill_frags(struct netfront_queue *queue,
893 struct sk_buff *skb,
894 struct sk_buff_head *list)
895{
896 struct skb_shared_info *shinfo = skb_shinfo(skb);
897 RING_IDX cons = queue->rx.rsp_cons;
898 struct sk_buff *nskb;
899
900 while ((nskb = __skb_dequeue(list))) {
901 struct xen_netif_rx_response *rx =
902 RING_GET_RESPONSE(&queue->rx, ++cons);
903 skb_frag_t *nfrag = &skb_shinfo(nskb)->frags[0];
904
905 if (shinfo->nr_frags == MAX_SKB_FRAGS) {
906 unsigned int pull_to = NETFRONT_SKB_CB(skb)->pull_to;
907
908 BUG_ON(pull_to <= skb_headlen(skb));
909 __pskb_pull_tail(skb, pull_to - skb_headlen(skb));
910 }
911 BUG_ON(shinfo->nr_frags >= MAX_SKB_FRAGS);
912
913 skb_add_rx_frag(skb, shinfo->nr_frags, skb_frag_page(nfrag),
914 rx->offset, rx->status, PAGE_SIZE);
915
916 skb_shinfo(nskb)->nr_frags = 0;
917 kfree_skb(nskb);
918 }
919
920 return cons;
921}
922
923static int checksum_setup(struct net_device *dev, struct sk_buff *skb)
924{
925 bool recalculate_partial_csum = false;
926
927 /*
928 * A GSO SKB must be CHECKSUM_PARTIAL. However some buggy
929 * peers can fail to set NETRXF_csum_blank when sending a GSO
930 * frame. In this case force the SKB to CHECKSUM_PARTIAL and
931 * recalculate the partial checksum.
932 */
933 if (skb->ip_summed != CHECKSUM_PARTIAL && skb_is_gso(skb)) {
934 struct netfront_info *np = netdev_priv(dev);
935 atomic_inc(&np->rx_gso_checksum_fixup);
936 skb->ip_summed = CHECKSUM_PARTIAL;
937 recalculate_partial_csum = true;
938 }
939
940 /* A non-CHECKSUM_PARTIAL SKB does not require setup. */
941 if (skb->ip_summed != CHECKSUM_PARTIAL)
942 return 0;
943
944 return skb_checksum_setup(skb, recalculate_partial_csum);
945}
946
947static int handle_incoming_queue(struct netfront_queue *queue,
948 struct sk_buff_head *rxq)
949{
950 struct netfront_stats *rx_stats = this_cpu_ptr(queue->info->rx_stats);
951 int packets_dropped = 0;
952 struct sk_buff *skb;
953
954 while ((skb = __skb_dequeue(rxq)) != NULL) {
955 int pull_to = NETFRONT_SKB_CB(skb)->pull_to;
956
957 if (pull_to > skb_headlen(skb))
958 __pskb_pull_tail(skb, pull_to - skb_headlen(skb));
959
960 /* Ethernet work: Delayed to here as it peeks the header. */
961 skb->protocol = eth_type_trans(skb, queue->info->netdev);
962 skb_reset_network_header(skb);
963
964 if (checksum_setup(queue->info->netdev, skb)) {
965 kfree_skb(skb);
966 packets_dropped++;
967 queue->info->netdev->stats.rx_errors++;
968 continue;
969 }
970
971 u64_stats_update_begin(&rx_stats->syncp);
972 rx_stats->packets++;
973 rx_stats->bytes += skb->len;
974 u64_stats_update_end(&rx_stats->syncp);
975
976 /* Pass it up. */
977 napi_gro_receive(&queue->napi, skb);
978 }
979
980 return packets_dropped;
981}
982
983static int xennet_poll(struct napi_struct *napi, int budget)
984{
985 struct netfront_queue *queue = container_of(napi, struct netfront_queue, napi);
986 struct net_device *dev = queue->info->netdev;
987 struct sk_buff *skb;
988 struct netfront_rx_info rinfo;
989 struct xen_netif_rx_response *rx = &rinfo.rx;
990 struct xen_netif_extra_info *extras = rinfo.extras;
991 RING_IDX i, rp;
992 int work_done;
993 struct sk_buff_head rxq;
994 struct sk_buff_head errq;
995 struct sk_buff_head tmpq;
996 int err;
997
998 spin_lock(&queue->rx_lock);
999
1000 skb_queue_head_init(&rxq);
1001 skb_queue_head_init(&errq);
1002 skb_queue_head_init(&tmpq);
1003
1004 rp = queue->rx.sring->rsp_prod;
1005 rmb(); /* Ensure we see queued responses up to 'rp'. */
1006
1007 i = queue->rx.rsp_cons;
1008 work_done = 0;
1009 while ((i != rp) && (work_done < budget)) {
1010 memcpy(rx, RING_GET_RESPONSE(&queue->rx, i), sizeof(*rx));
1011 memset(extras, 0, sizeof(rinfo.extras));
1012
1013 err = xennet_get_responses(queue, &rinfo, rp, &tmpq);
1014
1015 if (unlikely(err)) {
1016err:
1017 while ((skb = __skb_dequeue(&tmpq)))
1018 __skb_queue_tail(&errq, skb);
1019 dev->stats.rx_errors++;
1020 i = queue->rx.rsp_cons;
1021 continue;
1022 }
1023
1024 skb = __skb_dequeue(&tmpq);
1025
1026 if (extras[XEN_NETIF_EXTRA_TYPE_GSO - 1].type) {
1027 struct xen_netif_extra_info *gso;
1028 gso = &extras[XEN_NETIF_EXTRA_TYPE_GSO - 1];
1029
1030 if (unlikely(xennet_set_skb_gso(skb, gso))) {
1031 __skb_queue_head(&tmpq, skb);
1032 queue->rx.rsp_cons += skb_queue_len(&tmpq);
1033 goto err;
1034 }
1035 }
1036
1037 NETFRONT_SKB_CB(skb)->pull_to = rx->status;
1038 if (NETFRONT_SKB_CB(skb)->pull_to > RX_COPY_THRESHOLD)
1039 NETFRONT_SKB_CB(skb)->pull_to = RX_COPY_THRESHOLD;
1040
1041 skb_shinfo(skb)->frags[0].page_offset = rx->offset;
1042 skb_frag_size_set(&skb_shinfo(skb)->frags[0], rx->status);
1043 skb->data_len = rx->status;
1044 skb->len += rx->status;
1045
1046 i = xennet_fill_frags(queue, skb, &tmpq);
1047
1048 if (rx->flags & XEN_NETRXF_csum_blank)
1049 skb->ip_summed = CHECKSUM_PARTIAL;
1050 else if (rx->flags & XEN_NETRXF_data_validated)
1051 skb->ip_summed = CHECKSUM_UNNECESSARY;
1052
1053 __skb_queue_tail(&rxq, skb);
1054
1055 queue->rx.rsp_cons = ++i;
1056 work_done++;
1057 }
1058
1059 __skb_queue_purge(&errq);
1060
1061 work_done -= handle_incoming_queue(queue, &rxq);
1062
1063 xennet_alloc_rx_buffers(queue);
1064
1065 if (work_done < budget) {
1066 int more_to_do = 0;
1067
1068 napi_complete_done(napi, work_done);
1069
1070 RING_FINAL_CHECK_FOR_RESPONSES(&queue->rx, more_to_do);
1071 if (more_to_do)
1072 napi_schedule(napi);
1073 }
1074
1075 spin_unlock(&queue->rx_lock);
1076
1077 return work_done;
1078}
1079
1080static int xennet_change_mtu(struct net_device *dev, int mtu)
1081{
1082 int max = xennet_can_sg(dev) ? XEN_NETIF_MAX_TX_SIZE : ETH_DATA_LEN;
1083
1084 if (mtu > max)
1085 return -EINVAL;
1086 dev->mtu = mtu;
1087 return 0;
1088}
1089
1090static void xennet_get_stats64(struct net_device *dev,
1091 struct rtnl_link_stats64 *tot)
1092{
1093 struct netfront_info *np = netdev_priv(dev);
1094 int cpu;
1095
1096 for_each_possible_cpu(cpu) {
1097 struct netfront_stats *rx_stats = per_cpu_ptr(np->rx_stats, cpu);
1098 struct netfront_stats *tx_stats = per_cpu_ptr(np->tx_stats, cpu);
1099 u64 rx_packets, rx_bytes, tx_packets, tx_bytes;
1100 unsigned int start;
1101
1102 do {
1103 start = u64_stats_fetch_begin_irq(&tx_stats->syncp);
1104 tx_packets = tx_stats->packets;
1105 tx_bytes = tx_stats->bytes;
1106 } while (u64_stats_fetch_retry_irq(&tx_stats->syncp, start));
1107
1108 do {
1109 start = u64_stats_fetch_begin_irq(&rx_stats->syncp);
1110 rx_packets = rx_stats->packets;
1111 rx_bytes = rx_stats->bytes;
1112 } while (u64_stats_fetch_retry_irq(&rx_stats->syncp, start));
1113
1114 tot->rx_packets += rx_packets;
1115 tot->tx_packets += tx_packets;
1116 tot->rx_bytes += rx_bytes;
1117 tot->tx_bytes += tx_bytes;
1118 }
1119
1120 tot->rx_errors = dev->stats.rx_errors;
1121 tot->tx_dropped = dev->stats.tx_dropped;
1122}
1123
1124static void xennet_release_tx_bufs(struct netfront_queue *queue)
1125{
1126 struct sk_buff *skb;
1127 int i;
1128
1129 for (i = 0; i < NET_TX_RING_SIZE; i++) {
1130 /* Skip over entries which are actually freelist references */
1131 if (skb_entry_is_link(&queue->tx_skbs[i]))
1132 continue;
1133
1134 skb = queue->tx_skbs[i].skb;
1135 get_page(queue->grant_tx_page[i]);
1136 gnttab_end_foreign_access(queue->grant_tx_ref[i],
1137 GNTMAP_readonly,
1138 (unsigned long)page_address(queue->grant_tx_page[i]));
1139 queue->grant_tx_page[i] = NULL;
1140 queue->grant_tx_ref[i] = GRANT_INVALID_REF;
1141 add_id_to_freelist(&queue->tx_skb_freelist, queue->tx_skbs, i);
1142 dev_kfree_skb_irq(skb);
1143 }
1144}
1145
1146static void xennet_release_rx_bufs(struct netfront_queue *queue)
1147{
1148 int id, ref;
1149
1150 spin_lock_bh(&queue->rx_lock);
1151
1152 for (id = 0; id < NET_RX_RING_SIZE; id++) {
1153 struct sk_buff *skb;
1154 struct page *page;
1155
1156 skb = queue->rx_skbs[id];
1157 if (!skb)
1158 continue;
1159
1160 ref = queue->grant_rx_ref[id];
1161 if (ref == GRANT_INVALID_REF)
1162 continue;
1163
1164 page = skb_frag_page(&skb_shinfo(skb)->frags[0]);
1165
1166 /* gnttab_end_foreign_access() needs a page ref until
1167 * foreign access is ended (which may be deferred).
1168 */
1169 get_page(page);
1170 gnttab_end_foreign_access(ref, 0,
1171 (unsigned long)page_address(page));
1172 queue->grant_rx_ref[id] = GRANT_INVALID_REF;
1173
1174 kfree_skb(skb);
1175 }
1176
1177 spin_unlock_bh(&queue->rx_lock);
1178}
1179
1180static netdev_features_t xennet_fix_features(struct net_device *dev,
1181 netdev_features_t features)
1182{
1183 struct netfront_info *np = netdev_priv(dev);
1184
1185 if (features & NETIF_F_SG &&
1186 !xenbus_read_unsigned(np->xbdev->otherend, "feature-sg", 0))
1187 features &= ~NETIF_F_SG;
1188
1189 if (features & NETIF_F_IPV6_CSUM &&
1190 !xenbus_read_unsigned(np->xbdev->otherend,
1191 "feature-ipv6-csum-offload", 0))
1192 features &= ~NETIF_F_IPV6_CSUM;
1193
1194 if (features & NETIF_F_TSO &&
1195 !xenbus_read_unsigned(np->xbdev->otherend, "feature-gso-tcpv4", 0))
1196 features &= ~NETIF_F_TSO;
1197
1198 if (features & NETIF_F_TSO6 &&
1199 !xenbus_read_unsigned(np->xbdev->otherend, "feature-gso-tcpv6", 0))
1200 features &= ~NETIF_F_TSO6;
1201
1202 return features;
1203}
1204
1205static int xennet_set_features(struct net_device *dev,
1206 netdev_features_t features)
1207{
1208 if (!(features & NETIF_F_SG) && dev->mtu > ETH_DATA_LEN) {
1209 netdev_info(dev, "Reducing MTU because no SG offload");
1210 dev->mtu = ETH_DATA_LEN;
1211 }
1212
1213 return 0;
1214}
1215
1216static irqreturn_t xennet_tx_interrupt(int irq, void *dev_id)
1217{
1218 struct netfront_queue *queue = dev_id;
1219 unsigned long flags;
1220
1221 spin_lock_irqsave(&queue->tx_lock, flags);
1222 xennet_tx_buf_gc(queue);
1223 spin_unlock_irqrestore(&queue->tx_lock, flags);
1224
1225 return IRQ_HANDLED;
1226}
1227
1228static irqreturn_t xennet_rx_interrupt(int irq, void *dev_id)
1229{
1230 struct netfront_queue *queue = dev_id;
1231 struct net_device *dev = queue->info->netdev;
1232
1233 if (likely(netif_carrier_ok(dev) &&
1234 RING_HAS_UNCONSUMED_RESPONSES(&queue->rx)))
1235 napi_schedule(&queue->napi);
1236
1237 return IRQ_HANDLED;
1238}
1239
1240static irqreturn_t xennet_interrupt(int irq, void *dev_id)
1241{
1242 xennet_tx_interrupt(irq, dev_id);
1243 xennet_rx_interrupt(irq, dev_id);
1244 return IRQ_HANDLED;
1245}
1246
1247#ifdef CONFIG_NET_POLL_CONTROLLER
1248static void xennet_poll_controller(struct net_device *dev)
1249{
1250 /* Poll each queue */
1251 struct netfront_info *info = netdev_priv(dev);
1252 unsigned int num_queues = dev->real_num_tx_queues;
1253 unsigned int i;
1254 for (i = 0; i < num_queues; ++i)
1255 xennet_interrupt(0, &info->queues[i]);
1256}
1257#endif
1258
1259static const struct net_device_ops xennet_netdev_ops = {
1260 .ndo_open = xennet_open,
1261 .ndo_stop = xennet_close,
1262 .ndo_start_xmit = xennet_start_xmit,
1263 .ndo_change_mtu = xennet_change_mtu,
1264 .ndo_get_stats64 = xennet_get_stats64,
1265 .ndo_set_mac_address = eth_mac_addr,
1266 .ndo_validate_addr = eth_validate_addr,
1267 .ndo_fix_features = xennet_fix_features,
1268 .ndo_set_features = xennet_set_features,
1269 .ndo_select_queue = xennet_select_queue,
1270#ifdef CONFIG_NET_POLL_CONTROLLER
1271 .ndo_poll_controller = xennet_poll_controller,
1272#endif
1273};
1274
1275static void xennet_free_netdev(struct net_device *netdev)
1276{
1277 struct netfront_info *np = netdev_priv(netdev);
1278
1279 free_percpu(np->rx_stats);
1280 free_percpu(np->tx_stats);
1281 free_netdev(netdev);
1282}
1283
1284static struct net_device *xennet_create_dev(struct xenbus_device *dev)
1285{
1286 int err;
1287 struct net_device *netdev;
1288 struct netfront_info *np;
1289
1290 netdev = alloc_etherdev_mq(sizeof(struct netfront_info), xennet_max_queues);
1291 if (!netdev)
1292 return ERR_PTR(-ENOMEM);
1293
1294 np = netdev_priv(netdev);
1295 np->xbdev = dev;
1296
1297 np->queues = NULL;
1298
1299 err = -ENOMEM;
1300 np->rx_stats = netdev_alloc_pcpu_stats(struct netfront_stats);
1301 if (np->rx_stats == NULL)
1302 goto exit;
1303 np->tx_stats = netdev_alloc_pcpu_stats(struct netfront_stats);
1304 if (np->tx_stats == NULL)
1305 goto exit;
1306
1307 netdev->netdev_ops = &xennet_netdev_ops;
1308
1309 netdev->features = NETIF_F_IP_CSUM | NETIF_F_RXCSUM |
1310 NETIF_F_GSO_ROBUST;
1311 netdev->hw_features = NETIF_F_SG |
1312 NETIF_F_IPV6_CSUM |
1313 NETIF_F_TSO | NETIF_F_TSO6;
1314
1315 /*
1316 * Assume that all hw features are available for now. This set
1317 * will be adjusted by the call to netdev_update_features() in
1318 * xennet_connect() which is the earliest point where we can
1319 * negotiate with the backend regarding supported features.
1320 */
1321 netdev->features |= netdev->hw_features;
1322
1323 netdev->ethtool_ops = &xennet_ethtool_ops;
1324 netdev->min_mtu = ETH_MIN_MTU;
1325 netdev->max_mtu = XEN_NETIF_MAX_TX_SIZE;
1326 SET_NETDEV_DEV(netdev, &dev->dev);
1327
1328 np->netdev = netdev;
1329
1330 netif_carrier_off(netdev);
1331
1332 xenbus_switch_state(dev, XenbusStateInitialising);
1333 return netdev;
1334
1335 exit:
1336 xennet_free_netdev(netdev);
1337 return ERR_PTR(err);
1338}
1339
1340/**
1341 * Entry point to this code when a new device is created. Allocate the basic
1342 * structures and the ring buffers for communication with the backend, and
1343 * inform the backend of the appropriate details for those.
1344 */
1345static int netfront_probe(struct xenbus_device *dev,
1346 const struct xenbus_device_id *id)
1347{
1348 int err;
1349 struct net_device *netdev;
1350 struct netfront_info *info;
1351
1352 netdev = xennet_create_dev(dev);
1353 if (IS_ERR(netdev)) {
1354 err = PTR_ERR(netdev);
1355 xenbus_dev_fatal(dev, err, "creating netdev");
1356 return err;
1357 }
1358
1359 info = netdev_priv(netdev);
1360 dev_set_drvdata(&dev->dev, info);
1361#ifdef CONFIG_SYSFS
1362 info->netdev->sysfs_groups[0] = &xennet_dev_group;
1363#endif
1364
1365 return 0;
1366}
1367
1368static void xennet_end_access(int ref, void *page)
1369{
1370 /* This frees the page as a side-effect */
1371 if (ref != GRANT_INVALID_REF)
1372 gnttab_end_foreign_access(ref, 0, (unsigned long)page);
1373}
1374
1375static void xennet_disconnect_backend(struct netfront_info *info)
1376{
1377 unsigned int i = 0;
1378 unsigned int num_queues = info->netdev->real_num_tx_queues;
1379
1380 netif_carrier_off(info->netdev);
1381
1382 for (i = 0; i < num_queues && info->queues; ++i) {
1383 struct netfront_queue *queue = &info->queues[i];
1384
1385 del_timer_sync(&queue->rx_refill_timer);
1386
1387 if (queue->tx_irq && (queue->tx_irq == queue->rx_irq))
1388 unbind_from_irqhandler(queue->tx_irq, queue);
1389 if (queue->tx_irq && (queue->tx_irq != queue->rx_irq)) {
1390 unbind_from_irqhandler(queue->tx_irq, queue);
1391 unbind_from_irqhandler(queue->rx_irq, queue);
1392 }
1393 queue->tx_evtchn = queue->rx_evtchn = 0;
1394 queue->tx_irq = queue->rx_irq = 0;
1395
1396 if (netif_running(info->netdev))
1397 napi_synchronize(&queue->napi);
1398
1399 xennet_release_tx_bufs(queue);
1400 xennet_release_rx_bufs(queue);
1401 gnttab_free_grant_references(queue->gref_tx_head);
1402 gnttab_free_grant_references(queue->gref_rx_head);
1403
1404 /* End access and free the pages */
1405 xennet_end_access(queue->tx_ring_ref, queue->tx.sring);
1406 xennet_end_access(queue->rx_ring_ref, queue->rx.sring);
1407
1408 queue->tx_ring_ref = GRANT_INVALID_REF;
1409 queue->rx_ring_ref = GRANT_INVALID_REF;
1410 queue->tx.sring = NULL;
1411 queue->rx.sring = NULL;
1412 }
1413}
1414
1415/**
1416 * We are reconnecting to the backend, due to a suspend/resume, or a backend
1417 * driver restart. We tear down our netif structure and recreate it, but
1418 * leave the device-layer structures intact so that this is transparent to the
1419 * rest of the kernel.
1420 */
1421static int netfront_resume(struct xenbus_device *dev)
1422{
1423 struct netfront_info *info = dev_get_drvdata(&dev->dev);
1424
1425 dev_dbg(&dev->dev, "%s\n", dev->nodename);
1426
1427 xennet_disconnect_backend(info);
1428 return 0;
1429}
1430
1431static int xen_net_read_mac(struct xenbus_device *dev, u8 mac[])
1432{
1433 char *s, *e, *macstr;
1434 int i;
1435
1436 macstr = s = xenbus_read(XBT_NIL, dev->nodename, "mac", NULL);
1437 if (IS_ERR(macstr))
1438 return PTR_ERR(macstr);
1439
1440 for (i = 0; i < ETH_ALEN; i++) {
1441 mac[i] = simple_strtoul(s, &e, 16);
1442 if ((s == e) || (*e != ((i == ETH_ALEN-1) ? '\0' : ':'))) {
1443 kfree(macstr);
1444 return -ENOENT;
1445 }
1446 s = e+1;
1447 }
1448
1449 kfree(macstr);
1450 return 0;
1451}
1452
1453static int setup_netfront_single(struct netfront_queue *queue)
1454{
1455 int err;
1456
1457 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->tx_evtchn);
1458 if (err < 0)
1459 goto fail;
1460
1461 err = bind_evtchn_to_irqhandler(queue->tx_evtchn,
1462 xennet_interrupt,
1463 0, queue->info->netdev->name, queue);
1464 if (err < 0)
1465 goto bind_fail;
1466 queue->rx_evtchn = queue->tx_evtchn;
1467 queue->rx_irq = queue->tx_irq = err;
1468
1469 return 0;
1470
1471bind_fail:
1472 xenbus_free_evtchn(queue->info->xbdev, queue->tx_evtchn);
1473 queue->tx_evtchn = 0;
1474fail:
1475 return err;
1476}
1477
1478static int setup_netfront_split(struct netfront_queue *queue)
1479{
1480 int err;
1481
1482 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->tx_evtchn);
1483 if (err < 0)
1484 goto fail;
1485 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->rx_evtchn);
1486 if (err < 0)
1487 goto alloc_rx_evtchn_fail;
1488
1489 snprintf(queue->tx_irq_name, sizeof(queue->tx_irq_name),
1490 "%s-tx", queue->name);
1491 err = bind_evtchn_to_irqhandler(queue->tx_evtchn,
1492 xennet_tx_interrupt,
1493 0, queue->tx_irq_name, queue);
1494 if (err < 0)
1495 goto bind_tx_fail;
1496 queue->tx_irq = err;
1497
1498 snprintf(queue->rx_irq_name, sizeof(queue->rx_irq_name),
1499 "%s-rx", queue->name);
1500 err = bind_evtchn_to_irqhandler(queue->rx_evtchn,
1501 xennet_rx_interrupt,
1502 0, queue->rx_irq_name, queue);
1503 if (err < 0)
1504 goto bind_rx_fail;
1505 queue->rx_irq = err;
1506
1507 return 0;
1508
1509bind_rx_fail:
1510 unbind_from_irqhandler(queue->tx_irq, queue);
1511 queue->tx_irq = 0;
1512bind_tx_fail:
1513 xenbus_free_evtchn(queue->info->xbdev, queue->rx_evtchn);
1514 queue->rx_evtchn = 0;
1515alloc_rx_evtchn_fail:
1516 xenbus_free_evtchn(queue->info->xbdev, queue->tx_evtchn);
1517 queue->tx_evtchn = 0;
1518fail:
1519 return err;
1520}
1521
1522static int setup_netfront(struct xenbus_device *dev,
1523 struct netfront_queue *queue, unsigned int feature_split_evtchn)
1524{
1525 struct xen_netif_tx_sring *txs;
1526 struct xen_netif_rx_sring *rxs;
1527 grant_ref_t gref;
1528 int err;
1529
1530 queue->tx_ring_ref = GRANT_INVALID_REF;
1531 queue->rx_ring_ref = GRANT_INVALID_REF;
1532 queue->rx.sring = NULL;
1533 queue->tx.sring = NULL;
1534
1535 txs = (struct xen_netif_tx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH);
1536 if (!txs) {
1537 err = -ENOMEM;
1538 xenbus_dev_fatal(dev, err, "allocating tx ring page");
1539 goto fail;
1540 }
1541 SHARED_RING_INIT(txs);
1542 FRONT_RING_INIT(&queue->tx, txs, XEN_PAGE_SIZE);
1543
1544 err = xenbus_grant_ring(dev, txs, 1, &gref);
1545 if (err < 0)
1546 goto grant_tx_ring_fail;
1547 queue->tx_ring_ref = gref;
1548
1549 rxs = (struct xen_netif_rx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH);
1550 if (!rxs) {
1551 err = -ENOMEM;
1552 xenbus_dev_fatal(dev, err, "allocating rx ring page");
1553 goto alloc_rx_ring_fail;
1554 }
1555 SHARED_RING_INIT(rxs);
1556 FRONT_RING_INIT(&queue->rx, rxs, XEN_PAGE_SIZE);
1557
1558 err = xenbus_grant_ring(dev, rxs, 1, &gref);
1559 if (err < 0)
1560 goto grant_rx_ring_fail;
1561 queue->rx_ring_ref = gref;
1562
1563 if (feature_split_evtchn)
1564 err = setup_netfront_split(queue);
1565 /* setup single event channel if
1566 * a) feature-split-event-channels == 0
1567 * b) feature-split-event-channels == 1 but failed to setup
1568 */
1569 if (!feature_split_evtchn || (feature_split_evtchn && err))
1570 err = setup_netfront_single(queue);
1571
1572 if (err)
1573 goto alloc_evtchn_fail;
1574
1575 return 0;
1576
1577 /* If we fail to setup netfront, it is safe to just revoke access to
1578 * granted pages because backend is not accessing it at this point.
1579 */
1580alloc_evtchn_fail:
1581 gnttab_end_foreign_access_ref(queue->rx_ring_ref, 0);
1582grant_rx_ring_fail:
1583 free_page((unsigned long)rxs);
1584alloc_rx_ring_fail:
1585 gnttab_end_foreign_access_ref(queue->tx_ring_ref, 0);
1586grant_tx_ring_fail:
1587 free_page((unsigned long)txs);
1588fail:
1589 return err;
1590}
1591
1592/* Queue-specific initialisation
1593 * This used to be done in xennet_create_dev() but must now
1594 * be run per-queue.
1595 */
1596static int xennet_init_queue(struct netfront_queue *queue)
1597{
1598 unsigned short i;
1599 int err = 0;
1600
1601 spin_lock_init(&queue->tx_lock);
1602 spin_lock_init(&queue->rx_lock);
1603
1604 timer_setup(&queue->rx_refill_timer, rx_refill_timeout, 0);
1605
1606 snprintf(queue->name, sizeof(queue->name), "%s-q%u",
1607 queue->info->netdev->name, queue->id);
1608
1609 /* Initialise tx_skbs as a free chain containing every entry. */
1610 queue->tx_skb_freelist = 0;
1611 for (i = 0; i < NET_TX_RING_SIZE; i++) {
1612 skb_entry_set_link(&queue->tx_skbs[i], i+1);
1613 queue->grant_tx_ref[i] = GRANT_INVALID_REF;
1614 queue->grant_tx_page[i] = NULL;
1615 }
1616
1617 /* Clear out rx_skbs */
1618 for (i = 0; i < NET_RX_RING_SIZE; i++) {
1619 queue->rx_skbs[i] = NULL;
1620 queue->grant_rx_ref[i] = GRANT_INVALID_REF;
1621 }
1622
1623 /* A grant for every tx ring slot */
1624 if (gnttab_alloc_grant_references(NET_TX_RING_SIZE,
1625 &queue->gref_tx_head) < 0) {
1626 pr_alert("can't alloc tx grant refs\n");
1627 err = -ENOMEM;
1628 goto exit;
1629 }
1630
1631 /* A grant for every rx ring slot */
1632 if (gnttab_alloc_grant_references(NET_RX_RING_SIZE,
1633 &queue->gref_rx_head) < 0) {
1634 pr_alert("can't alloc rx grant refs\n");
1635 err = -ENOMEM;
1636 goto exit_free_tx;
1637 }
1638
1639 return 0;
1640
1641 exit_free_tx:
1642 gnttab_free_grant_references(queue->gref_tx_head);
1643 exit:
1644 return err;
1645}
1646
1647static int write_queue_xenstore_keys(struct netfront_queue *queue,
1648 struct xenbus_transaction *xbt, int write_hierarchical)
1649{
1650 /* Write the queue-specific keys into XenStore in the traditional
1651 * way for a single queue, or in a queue subkeys for multiple
1652 * queues.
1653 */
1654 struct xenbus_device *dev = queue->info->xbdev;
1655 int err;
1656 const char *message;
1657 char *path;
1658 size_t pathsize;
1659
1660 /* Choose the correct place to write the keys */
1661 if (write_hierarchical) {
1662 pathsize = strlen(dev->nodename) + 10;
1663 path = kzalloc(pathsize, GFP_KERNEL);
1664 if (!path) {
1665 err = -ENOMEM;
1666 message = "out of memory while writing ring references";
1667 goto error;
1668 }
1669 snprintf(path, pathsize, "%s/queue-%u",
1670 dev->nodename, queue->id);
1671 } else {
1672 path = (char *)dev->nodename;
1673 }
1674
1675 /* Write ring references */
1676 err = xenbus_printf(*xbt, path, "tx-ring-ref", "%u",
1677 queue->tx_ring_ref);
1678 if (err) {
1679 message = "writing tx-ring-ref";
1680 goto error;
1681 }
1682
1683 err = xenbus_printf(*xbt, path, "rx-ring-ref", "%u",
1684 queue->rx_ring_ref);
1685 if (err) {
1686 message = "writing rx-ring-ref";
1687 goto error;
1688 }
1689
1690 /* Write event channels; taking into account both shared
1691 * and split event channel scenarios.
1692 */
1693 if (queue->tx_evtchn == queue->rx_evtchn) {
1694 /* Shared event channel */
1695 err = xenbus_printf(*xbt, path,
1696 "event-channel", "%u", queue->tx_evtchn);
1697 if (err) {
1698 message = "writing event-channel";
1699 goto error;
1700 }
1701 } else {
1702 /* Split event channels */
1703 err = xenbus_printf(*xbt, path,
1704 "event-channel-tx", "%u", queue->tx_evtchn);
1705 if (err) {
1706 message = "writing event-channel-tx";
1707 goto error;
1708 }
1709
1710 err = xenbus_printf(*xbt, path,
1711 "event-channel-rx", "%u", queue->rx_evtchn);
1712 if (err) {
1713 message = "writing event-channel-rx";
1714 goto error;
1715 }
1716 }
1717
1718 if (write_hierarchical)
1719 kfree(path);
1720 return 0;
1721
1722error:
1723 if (write_hierarchical)
1724 kfree(path);
1725 xenbus_dev_fatal(dev, err, "%s", message);
1726 return err;
1727}
1728
1729static void xennet_destroy_queues(struct netfront_info *info)
1730{
1731 unsigned int i;
1732
1733 for (i = 0; i < info->netdev->real_num_tx_queues; i++) {
1734 struct netfront_queue *queue = &info->queues[i];
1735
1736 if (netif_running(info->netdev))
1737 napi_disable(&queue->napi);
1738 netif_napi_del(&queue->napi);
1739 }
1740
1741 kfree(info->queues);
1742 info->queues = NULL;
1743}
1744
1745static int xennet_create_queues(struct netfront_info *info,
1746 unsigned int *num_queues)
1747{
1748 unsigned int i;
1749 int ret;
1750
1751 info->queues = kcalloc(*num_queues, sizeof(struct netfront_queue),
1752 GFP_KERNEL);
1753 if (!info->queues)
1754 return -ENOMEM;
1755
1756 for (i = 0; i < *num_queues; i++) {
1757 struct netfront_queue *queue = &info->queues[i];
1758
1759 queue->id = i;
1760 queue->info = info;
1761
1762 ret = xennet_init_queue(queue);
1763 if (ret < 0) {
1764 dev_warn(&info->xbdev->dev,
1765 "only created %d queues\n", i);
1766 *num_queues = i;
1767 break;
1768 }
1769
1770 netif_napi_add(queue->info->netdev, &queue->napi,
1771 xennet_poll, 64);
1772 if (netif_running(info->netdev))
1773 napi_enable(&queue->napi);
1774 }
1775
1776 netif_set_real_num_tx_queues(info->netdev, *num_queues);
1777
1778 if (*num_queues == 0) {
1779 dev_err(&info->xbdev->dev, "no queues\n");
1780 return -EINVAL;
1781 }
1782 return 0;
1783}
1784
1785/* Common code used when first setting up, and when resuming. */
1786static int talk_to_netback(struct xenbus_device *dev,
1787 struct netfront_info *info)
1788{
1789 const char *message;
1790 struct xenbus_transaction xbt;
1791 int err;
1792 unsigned int feature_split_evtchn;
1793 unsigned int i = 0;
1794 unsigned int max_queues = 0;
1795 struct netfront_queue *queue = NULL;
1796 unsigned int num_queues = 1;
1797
1798 info->netdev->irq = 0;
1799
1800 /* Check if backend supports multiple queues */
1801 max_queues = xenbus_read_unsigned(info->xbdev->otherend,
1802 "multi-queue-max-queues", 1);
1803 num_queues = min(max_queues, xennet_max_queues);
1804
1805 /* Check feature-split-event-channels */
1806 feature_split_evtchn = xenbus_read_unsigned(info->xbdev->otherend,
1807 "feature-split-event-channels", 0);
1808
1809 /* Read mac addr. */
1810 err = xen_net_read_mac(dev, info->netdev->dev_addr);
1811 if (err) {
1812 xenbus_dev_fatal(dev, err, "parsing %s/mac", dev->nodename);
1813 goto out;
1814 }
1815
1816 rtnl_lock();
1817 if (info->queues)
1818 xennet_destroy_queues(info);
1819
1820 err = xennet_create_queues(info, &num_queues);
1821 if (err < 0) {
1822 xenbus_dev_fatal(dev, err, "creating queues");
1823 kfree(info->queues);
1824 info->queues = NULL;
1825 goto out;
1826 }
1827 rtnl_unlock();
1828
1829 /* Create shared ring, alloc event channel -- for each queue */
1830 for (i = 0; i < num_queues; ++i) {
1831 queue = &info->queues[i];
1832 err = setup_netfront(dev, queue, feature_split_evtchn);
1833 if (err)
1834 goto destroy_ring;
1835 }
1836
1837again:
1838 err = xenbus_transaction_start(&xbt);
1839 if (err) {
1840 xenbus_dev_fatal(dev, err, "starting transaction");
1841 goto destroy_ring;
1842 }
1843
1844 if (xenbus_exists(XBT_NIL,
1845 info->xbdev->otherend, "multi-queue-max-queues")) {
1846 /* Write the number of queues */
1847 err = xenbus_printf(xbt, dev->nodename,
1848 "multi-queue-num-queues", "%u", num_queues);
1849 if (err) {
1850 message = "writing multi-queue-num-queues";
1851 goto abort_transaction_no_dev_fatal;
1852 }
1853 }
1854
1855 if (num_queues == 1) {
1856 err = write_queue_xenstore_keys(&info->queues[0], &xbt, 0); /* flat */
1857 if (err)
1858 goto abort_transaction_no_dev_fatal;
1859 } else {
1860 /* Write the keys for each queue */
1861 for (i = 0; i < num_queues; ++i) {
1862 queue = &info->queues[i];
1863 err = write_queue_xenstore_keys(queue, &xbt, 1); /* hierarchical */
1864 if (err)
1865 goto abort_transaction_no_dev_fatal;
1866 }
1867 }
1868
1869 /* The remaining keys are not queue-specific */
1870 err = xenbus_printf(xbt, dev->nodename, "request-rx-copy", "%u",
1871 1);
1872 if (err) {
1873 message = "writing request-rx-copy";
1874 goto abort_transaction;
1875 }
1876
1877 err = xenbus_printf(xbt, dev->nodename, "feature-rx-notify", "%d", 1);
1878 if (err) {
1879 message = "writing feature-rx-notify";
1880 goto abort_transaction;
1881 }
1882
1883 err = xenbus_printf(xbt, dev->nodename, "feature-sg", "%d", 1);
1884 if (err) {
1885 message = "writing feature-sg";
1886 goto abort_transaction;
1887 }
1888
1889 err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv4", "%d", 1);
1890 if (err) {
1891 message = "writing feature-gso-tcpv4";
1892 goto abort_transaction;
1893 }
1894
1895 err = xenbus_write(xbt, dev->nodename, "feature-gso-tcpv6", "1");
1896 if (err) {
1897 message = "writing feature-gso-tcpv6";
1898 goto abort_transaction;
1899 }
1900
1901 err = xenbus_write(xbt, dev->nodename, "feature-ipv6-csum-offload",
1902 "1");
1903 if (err) {
1904 message = "writing feature-ipv6-csum-offload";
1905 goto abort_transaction;
1906 }
1907
1908 err = xenbus_transaction_end(xbt, 0);
1909 if (err) {
1910 if (err == -EAGAIN)
1911 goto again;
1912 xenbus_dev_fatal(dev, err, "completing transaction");
1913 goto destroy_ring;
1914 }
1915
1916 return 0;
1917
1918 abort_transaction:
1919 xenbus_dev_fatal(dev, err, "%s", message);
1920abort_transaction_no_dev_fatal:
1921 xenbus_transaction_end(xbt, 1);
1922 destroy_ring:
1923 xennet_disconnect_backend(info);
1924 rtnl_lock();
1925 xennet_destroy_queues(info);
1926 out:
1927 rtnl_unlock();
1928 device_unregister(&dev->dev);
1929 return err;
1930}
1931
1932static int xennet_connect(struct net_device *dev)
1933{
1934 struct netfront_info *np = netdev_priv(dev);
1935 unsigned int num_queues = 0;
1936 int err;
1937 unsigned int j = 0;
1938 struct netfront_queue *queue = NULL;
1939
1940 if (!xenbus_read_unsigned(np->xbdev->otherend, "feature-rx-copy", 0)) {
1941 dev_info(&dev->dev,
1942 "backend does not support copying receive path\n");
1943 return -ENODEV;
1944 }
1945
1946 err = talk_to_netback(np->xbdev, np);
1947 if (err)
1948 return err;
1949
1950 /* talk_to_netback() sets the correct number of queues */
1951 num_queues = dev->real_num_tx_queues;
1952
1953 rtnl_lock();
1954 netdev_update_features(dev);
1955 rtnl_unlock();
1956
1957 if (dev->reg_state == NETREG_UNINITIALIZED) {
1958 err = register_netdev(dev);
1959 if (err) {
1960 pr_warn("%s: register_netdev err=%d\n", __func__, err);
1961 device_unregister(&np->xbdev->dev);
1962 return err;
1963 }
1964 }
1965
1966 /*
1967 * All public and private state should now be sane. Get
1968 * ready to start sending and receiving packets and give the driver
1969 * domain a kick because we've probably just requeued some
1970 * packets.
1971 */
1972 netif_carrier_on(np->netdev);
1973 for (j = 0; j < num_queues; ++j) {
1974 queue = &np->queues[j];
1975
1976 notify_remote_via_irq(queue->tx_irq);
1977 if (queue->tx_irq != queue->rx_irq)
1978 notify_remote_via_irq(queue->rx_irq);
1979
1980 spin_lock_irq(&queue->tx_lock);
1981 xennet_tx_buf_gc(queue);
1982 spin_unlock_irq(&queue->tx_lock);
1983
1984 spin_lock_bh(&queue->rx_lock);
1985 xennet_alloc_rx_buffers(queue);
1986 spin_unlock_bh(&queue->rx_lock);
1987 }
1988
1989 return 0;
1990}
1991
1992/**
1993 * Callback received when the backend's state changes.
1994 */
1995static void netback_changed(struct xenbus_device *dev,
1996 enum xenbus_state backend_state)
1997{
1998 struct netfront_info *np = dev_get_drvdata(&dev->dev);
1999 struct net_device *netdev = np->netdev;
2000
2001 dev_dbg(&dev->dev, "%s\n", xenbus_strstate(backend_state));
2002
2003 switch (backend_state) {
2004 case XenbusStateInitialising:
2005 case XenbusStateInitialised:
2006 case XenbusStateReconfiguring:
2007 case XenbusStateReconfigured:
2008 break;
2009
2010 case XenbusStateUnknown:
2011 wake_up_all(&module_unload_q);
2012 break;
2013
2014 case XenbusStateInitWait:
2015 if (dev->state != XenbusStateInitialising)
2016 break;
2017 if (xennet_connect(netdev) != 0)
2018 break;
2019 xenbus_switch_state(dev, XenbusStateConnected);
2020 break;
2021
2022 case XenbusStateConnected:
2023 netdev_notify_peers(netdev);
2024 break;
2025
2026 case XenbusStateClosed:
2027 wake_up_all(&module_unload_q);
2028 if (dev->state == XenbusStateClosed)
2029 break;
2030 /* Missed the backend's CLOSING state -- fallthrough */
2031 case XenbusStateClosing:
2032 wake_up_all(&module_unload_q);
2033 xenbus_frontend_closed(dev);
2034 break;
2035 }
2036}
2037
2038static const struct xennet_stat {
2039 char name[ETH_GSTRING_LEN];
2040 u16 offset;
2041} xennet_stats[] = {
2042 {
2043 "rx_gso_checksum_fixup",
2044 offsetof(struct netfront_info, rx_gso_checksum_fixup)
2045 },
2046};
2047
2048static int xennet_get_sset_count(struct net_device *dev, int string_set)
2049{
2050 switch (string_set) {
2051 case ETH_SS_STATS:
2052 return ARRAY_SIZE(xennet_stats);
2053 default:
2054 return -EINVAL;
2055 }
2056}
2057
2058static void xennet_get_ethtool_stats(struct net_device *dev,
2059 struct ethtool_stats *stats, u64 * data)
2060{
2061 void *np = netdev_priv(dev);
2062 int i;
2063
2064 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++)
2065 data[i] = atomic_read((atomic_t *)(np + xennet_stats[i].offset));
2066}
2067
2068static void xennet_get_strings(struct net_device *dev, u32 stringset, u8 * data)
2069{
2070 int i;
2071
2072 switch (stringset) {
2073 case ETH_SS_STATS:
2074 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++)
2075 memcpy(data + i * ETH_GSTRING_LEN,
2076 xennet_stats[i].name, ETH_GSTRING_LEN);
2077 break;
2078 }
2079}
2080
2081static const struct ethtool_ops xennet_ethtool_ops =
2082{
2083 .get_link = ethtool_op_get_link,
2084
2085 .get_sset_count = xennet_get_sset_count,
2086 .get_ethtool_stats = xennet_get_ethtool_stats,
2087 .get_strings = xennet_get_strings,
2088};
2089
2090#ifdef CONFIG_SYSFS
2091static ssize_t show_rxbuf(struct device *dev,
2092 struct device_attribute *attr, char *buf)
2093{
2094 return sprintf(buf, "%lu\n", NET_RX_RING_SIZE);
2095}
2096
2097static ssize_t store_rxbuf(struct device *dev,
2098 struct device_attribute *attr,
2099 const char *buf, size_t len)
2100{
2101 char *endp;
2102 unsigned long target;
2103
2104 if (!capable(CAP_NET_ADMIN))
2105 return -EPERM;
2106
2107 target = simple_strtoul(buf, &endp, 0);
2108 if (endp == buf)
2109 return -EBADMSG;
2110
2111 /* rxbuf_min and rxbuf_max are no longer configurable. */
2112
2113 return len;
2114}
2115
2116static DEVICE_ATTR(rxbuf_min, 0644, show_rxbuf, store_rxbuf);
2117static DEVICE_ATTR(rxbuf_max, 0644, show_rxbuf, store_rxbuf);
2118static DEVICE_ATTR(rxbuf_cur, 0444, show_rxbuf, NULL);
2119
2120static struct attribute *xennet_dev_attrs[] = {
2121 &dev_attr_rxbuf_min.attr,
2122 &dev_attr_rxbuf_max.attr,
2123 &dev_attr_rxbuf_cur.attr,
2124 NULL
2125};
2126
2127static const struct attribute_group xennet_dev_group = {
2128 .attrs = xennet_dev_attrs
2129};
2130#endif /* CONFIG_SYSFS */
2131
2132static int xennet_remove(struct xenbus_device *dev)
2133{
2134 struct netfront_info *info = dev_get_drvdata(&dev->dev);
2135
2136 dev_dbg(&dev->dev, "%s\n", dev->nodename);
2137
2138 if (xenbus_read_driver_state(dev->otherend) != XenbusStateClosed) {
2139 xenbus_switch_state(dev, XenbusStateClosing);
2140 wait_event(module_unload_q,
2141 xenbus_read_driver_state(dev->otherend) ==
2142 XenbusStateClosing ||
2143 xenbus_read_driver_state(dev->otherend) ==
2144 XenbusStateUnknown);
2145
2146 xenbus_switch_state(dev, XenbusStateClosed);
2147 wait_event(module_unload_q,
2148 xenbus_read_driver_state(dev->otherend) ==
2149 XenbusStateClosed ||
2150 xenbus_read_driver_state(dev->otherend) ==
2151 XenbusStateUnknown);
2152 }
2153
2154 xennet_disconnect_backend(info);
2155
2156 if (info->netdev->reg_state == NETREG_REGISTERED)
2157 unregister_netdev(info->netdev);
2158
2159 if (info->queues) {
2160 rtnl_lock();
2161 xennet_destroy_queues(info);
2162 rtnl_unlock();
2163 }
2164 xennet_free_netdev(info->netdev);
2165
2166 return 0;
2167}
2168
2169static const struct xenbus_device_id netfront_ids[] = {
2170 { "vif" },
2171 { "" }
2172};
2173
2174static struct xenbus_driver netfront_driver = {
2175 .ids = netfront_ids,
2176 .probe = netfront_probe,
2177 .remove = xennet_remove,
2178 .resume = netfront_resume,
2179 .otherend_changed = netback_changed,
2180};
2181
2182static int __init netif_init(void)
2183{
2184 if (!xen_domain())
2185 return -ENODEV;
2186
2187 if (!xen_has_pv_nic_devices())
2188 return -ENODEV;
2189
2190 pr_info("Initialising Xen virtual ethernet driver\n");
2191
2192 /* Allow as many queues as there are CPUs inut max. 8 if user has not
2193 * specified a value.
2194 */
2195 if (xennet_max_queues == 0)
2196 xennet_max_queues = min_t(unsigned int, MAX_QUEUES_DEFAULT,
2197 num_online_cpus());
2198
2199 return xenbus_register_frontend(&netfront_driver);
2200}
2201module_init(netif_init);
2202
2203
2204static void __exit netif_exit(void)
2205{
2206 xenbus_unregister_driver(&netfront_driver);
2207}
2208module_exit(netif_exit);
2209
2210MODULE_DESCRIPTION("Xen virtual network device frontend");
2211MODULE_LICENSE("GPL");
2212MODULE_ALIAS("xen:vif");
2213MODULE_ALIAS("xennet");