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1/*
2 * Xenbus code for netif backend
3 *
4 * Copyright (C) 2005 Rusty Russell <rusty@rustcorp.com.au>
5 * Copyright (C) 2005 XenSource Ltd
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, see <http://www.gnu.org/licenses/>.
19*/
20
21#include "common.h"
22#include <linux/vmalloc.h>
23#include <linux/rtnetlink.h>
24
25struct backend_info {
26 struct xenbus_device *dev;
27 struct xenvif *vif;
28
29 /* This is the state that will be reflected in xenstore when any
30 * active hotplug script completes.
31 */
32 enum xenbus_state state;
33
34 enum xenbus_state frontend_state;
35 struct xenbus_watch hotplug_status_watch;
36 u8 have_hotplug_status_watch:1;
37
38 const char *hotplug_script;
39};
40
41static int connect_data_rings(struct backend_info *be,
42 struct xenvif_queue *queue);
43static void connect(struct backend_info *be);
44static int read_xenbus_vif_flags(struct backend_info *be);
45static int backend_create_xenvif(struct backend_info *be);
46static void unregister_hotplug_status_watch(struct backend_info *be);
47static void xen_unregister_watchers(struct xenvif *vif);
48static void set_backend_state(struct backend_info *be,
49 enum xenbus_state state);
50
51#ifdef CONFIG_DEBUG_FS
52struct dentry *xen_netback_dbg_root = NULL;
53
54static int xenvif_read_io_ring(struct seq_file *m, void *v)
55{
56 struct xenvif_queue *queue = m->private;
57 struct xen_netif_tx_back_ring *tx_ring = &queue->tx;
58 struct xen_netif_rx_back_ring *rx_ring = &queue->rx;
59 struct netdev_queue *dev_queue;
60
61 if (tx_ring->sring) {
62 struct xen_netif_tx_sring *sring = tx_ring->sring;
63
64 seq_printf(m, "Queue %d\nTX: nr_ents %u\n", queue->id,
65 tx_ring->nr_ents);
66 seq_printf(m, "req prod %u (%d) cons %u (%d) event %u (%d)\n",
67 sring->req_prod,
68 sring->req_prod - sring->rsp_prod,
69 tx_ring->req_cons,
70 tx_ring->req_cons - sring->rsp_prod,
71 sring->req_event,
72 sring->req_event - sring->rsp_prod);
73 seq_printf(m, "rsp prod %u (base) pvt %u (%d) event %u (%d)\n",
74 sring->rsp_prod,
75 tx_ring->rsp_prod_pvt,
76 tx_ring->rsp_prod_pvt - sring->rsp_prod,
77 sring->rsp_event,
78 sring->rsp_event - sring->rsp_prod);
79 seq_printf(m, "pending prod %u pending cons %u nr_pending_reqs %u\n",
80 queue->pending_prod,
81 queue->pending_cons,
82 nr_pending_reqs(queue));
83 seq_printf(m, "dealloc prod %u dealloc cons %u dealloc_queue %u\n\n",
84 queue->dealloc_prod,
85 queue->dealloc_cons,
86 queue->dealloc_prod - queue->dealloc_cons);
87 }
88
89 if (rx_ring->sring) {
90 struct xen_netif_rx_sring *sring = rx_ring->sring;
91
92 seq_printf(m, "RX: nr_ents %u\n", rx_ring->nr_ents);
93 seq_printf(m, "req prod %u (%d) cons %u (%d) event %u (%d)\n",
94 sring->req_prod,
95 sring->req_prod - sring->rsp_prod,
96 rx_ring->req_cons,
97 rx_ring->req_cons - sring->rsp_prod,
98 sring->req_event,
99 sring->req_event - sring->rsp_prod);
100 seq_printf(m, "rsp prod %u (base) pvt %u (%d) event %u (%d)\n\n",
101 sring->rsp_prod,
102 rx_ring->rsp_prod_pvt,
103 rx_ring->rsp_prod_pvt - sring->rsp_prod,
104 sring->rsp_event,
105 sring->rsp_event - sring->rsp_prod);
106 }
107
108 seq_printf(m, "NAPI state: %lx NAPI weight: %d TX queue len %u\n"
109 "Credit timer_pending: %d, credit: %lu, usec: %lu\n"
110 "remaining: %lu, expires: %lu, now: %lu\n",
111 queue->napi.state, queue->napi.weight,
112 skb_queue_len(&queue->tx_queue),
113 timer_pending(&queue->credit_timeout),
114 queue->credit_bytes,
115 queue->credit_usec,
116 queue->remaining_credit,
117 queue->credit_timeout.expires,
118 jiffies);
119
120 dev_queue = netdev_get_tx_queue(queue->vif->dev, queue->id);
121
122 seq_printf(m, "\nRx internal queue: len %u max %u pkts %u %s\n",
123 queue->rx_queue_len, queue->rx_queue_max,
124 skb_queue_len(&queue->rx_queue),
125 netif_tx_queue_stopped(dev_queue) ? "stopped" : "running");
126
127 return 0;
128}
129
130#define XENVIF_KICK_STR "kick"
131#define BUFFER_SIZE 32
132
133static ssize_t
134xenvif_write_io_ring(struct file *filp, const char __user *buf, size_t count,
135 loff_t *ppos)
136{
137 struct xenvif_queue *queue =
138 ((struct seq_file *)filp->private_data)->private;
139 int len;
140 char write[BUFFER_SIZE];
141
142 /* don't allow partial writes and check the length */
143 if (*ppos != 0)
144 return 0;
145 if (count >= sizeof(write))
146 return -ENOSPC;
147
148 len = simple_write_to_buffer(write,
149 sizeof(write) - 1,
150 ppos,
151 buf,
152 count);
153 if (len < 0)
154 return len;
155
156 write[len] = '\0';
157
158 if (!strncmp(write, XENVIF_KICK_STR, sizeof(XENVIF_KICK_STR) - 1))
159 xenvif_interrupt(0, (void *)queue);
160 else {
161 pr_warn("Unknown command to io_ring_q%d. Available: kick\n",
162 queue->id);
163 count = -EINVAL;
164 }
165 return count;
166}
167
168static int xenvif_io_ring_open(struct inode *inode, struct file *filp)
169{
170 int ret;
171 void *queue = NULL;
172
173 if (inode->i_private)
174 queue = inode->i_private;
175 ret = single_open(filp, xenvif_read_io_ring, queue);
176 filp->f_mode |= FMODE_PWRITE;
177 return ret;
178}
179
180static const struct file_operations xenvif_dbg_io_ring_ops_fops = {
181 .owner = THIS_MODULE,
182 .open = xenvif_io_ring_open,
183 .read = seq_read,
184 .llseek = seq_lseek,
185 .release = single_release,
186 .write = xenvif_write_io_ring,
187};
188
189static int xenvif_read_ctrl(struct seq_file *m, void *v)
190{
191 struct xenvif *vif = m->private;
192
193 xenvif_dump_hash_info(vif, m);
194
195 return 0;
196}
197
198static int xenvif_ctrl_open(struct inode *inode, struct file *filp)
199{
200 return single_open(filp, xenvif_read_ctrl, inode->i_private);
201}
202
203static const struct file_operations xenvif_dbg_ctrl_ops_fops = {
204 .owner = THIS_MODULE,
205 .open = xenvif_ctrl_open,
206 .read = seq_read,
207 .llseek = seq_lseek,
208 .release = single_release,
209};
210
211static void xenvif_debugfs_addif(struct xenvif *vif)
212{
213 struct dentry *pfile;
214 int i;
215
216 if (IS_ERR_OR_NULL(xen_netback_dbg_root))
217 return;
218
219 vif->xenvif_dbg_root = debugfs_create_dir(vif->dev->name,
220 xen_netback_dbg_root);
221 if (!IS_ERR_OR_NULL(vif->xenvif_dbg_root)) {
222 for (i = 0; i < vif->num_queues; ++i) {
223 char filename[sizeof("io_ring_q") + 4];
224
225 snprintf(filename, sizeof(filename), "io_ring_q%d", i);
226 pfile = debugfs_create_file(filename,
227 S_IRUSR | S_IWUSR,
228 vif->xenvif_dbg_root,
229 &vif->queues[i],
230 &xenvif_dbg_io_ring_ops_fops);
231 if (IS_ERR_OR_NULL(pfile))
232 pr_warn("Creation of io_ring file returned %ld!\n",
233 PTR_ERR(pfile));
234 }
235
236 if (vif->ctrl_irq) {
237 pfile = debugfs_create_file("ctrl",
238 S_IRUSR,
239 vif->xenvif_dbg_root,
240 vif,
241 &xenvif_dbg_ctrl_ops_fops);
242 if (IS_ERR_OR_NULL(pfile))
243 pr_warn("Creation of ctrl file returned %ld!\n",
244 PTR_ERR(pfile));
245 }
246 } else
247 netdev_warn(vif->dev,
248 "Creation of vif debugfs dir returned %ld!\n",
249 PTR_ERR(vif->xenvif_dbg_root));
250}
251
252static void xenvif_debugfs_delif(struct xenvif *vif)
253{
254 if (IS_ERR_OR_NULL(xen_netback_dbg_root))
255 return;
256
257 if (!IS_ERR_OR_NULL(vif->xenvif_dbg_root))
258 debugfs_remove_recursive(vif->xenvif_dbg_root);
259 vif->xenvif_dbg_root = NULL;
260}
261#endif /* CONFIG_DEBUG_FS */
262
263static int netback_remove(struct xenbus_device *dev)
264{
265 struct backend_info *be = dev_get_drvdata(&dev->dev);
266
267 set_backend_state(be, XenbusStateClosed);
268
269 unregister_hotplug_status_watch(be);
270 if (be->vif) {
271 kobject_uevent(&dev->dev.kobj, KOBJ_OFFLINE);
272 xen_unregister_watchers(be->vif);
273 xenbus_rm(XBT_NIL, dev->nodename, "hotplug-status");
274 xenvif_free(be->vif);
275 be->vif = NULL;
276 }
277 kfree(be->hotplug_script);
278 kfree(be);
279 dev_set_drvdata(&dev->dev, NULL);
280 return 0;
281}
282
283
284/**
285 * Entry point to this code when a new device is created. Allocate the basic
286 * structures and switch to InitWait.
287 */
288static int netback_probe(struct xenbus_device *dev,
289 const struct xenbus_device_id *id)
290{
291 const char *message;
292 struct xenbus_transaction xbt;
293 int err;
294 int sg;
295 const char *script;
296 struct backend_info *be = kzalloc(sizeof(struct backend_info),
297 GFP_KERNEL);
298 if (!be) {
299 xenbus_dev_fatal(dev, -ENOMEM,
300 "allocating backend structure");
301 return -ENOMEM;
302 }
303
304 be->dev = dev;
305 dev_set_drvdata(&dev->dev, be);
306
307 be->state = XenbusStateInitialising;
308 err = xenbus_switch_state(dev, XenbusStateInitialising);
309 if (err)
310 goto fail;
311
312 sg = 1;
313
314 do {
315 err = xenbus_transaction_start(&xbt);
316 if (err) {
317 xenbus_dev_fatal(dev, err, "starting transaction");
318 goto fail;
319 }
320
321 err = xenbus_printf(xbt, dev->nodename, "feature-sg", "%d", sg);
322 if (err) {
323 message = "writing feature-sg";
324 goto abort_transaction;
325 }
326
327 err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv4",
328 "%d", sg);
329 if (err) {
330 message = "writing feature-gso-tcpv4";
331 goto abort_transaction;
332 }
333
334 err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv6",
335 "%d", sg);
336 if (err) {
337 message = "writing feature-gso-tcpv6";
338 goto abort_transaction;
339 }
340
341 /* We support partial checksum setup for IPv6 packets */
342 err = xenbus_printf(xbt, dev->nodename,
343 "feature-ipv6-csum-offload",
344 "%d", 1);
345 if (err) {
346 message = "writing feature-ipv6-csum-offload";
347 goto abort_transaction;
348 }
349
350 /* We support rx-copy path. */
351 err = xenbus_printf(xbt, dev->nodename,
352 "feature-rx-copy", "%d", 1);
353 if (err) {
354 message = "writing feature-rx-copy";
355 goto abort_transaction;
356 }
357
358 /*
359 * We don't support rx-flip path (except old guests who don't
360 * grok this feature flag).
361 */
362 err = xenbus_printf(xbt, dev->nodename,
363 "feature-rx-flip", "%d", 0);
364 if (err) {
365 message = "writing feature-rx-flip";
366 goto abort_transaction;
367 }
368
369 /* We support dynamic multicast-control. */
370 err = xenbus_printf(xbt, dev->nodename,
371 "feature-multicast-control", "%d", 1);
372 if (err) {
373 message = "writing feature-multicast-control";
374 goto abort_transaction;
375 }
376
377 err = xenbus_printf(xbt, dev->nodename,
378 "feature-dynamic-multicast-control",
379 "%d", 1);
380 if (err) {
381 message = "writing feature-dynamic-multicast-control";
382 goto abort_transaction;
383 }
384
385 err = xenbus_transaction_end(xbt, 0);
386 } while (err == -EAGAIN);
387
388 if (err) {
389 xenbus_dev_fatal(dev, err, "completing transaction");
390 goto fail;
391 }
392
393 /*
394 * Split event channels support, this is optional so it is not
395 * put inside the above loop.
396 */
397 err = xenbus_printf(XBT_NIL, dev->nodename,
398 "feature-split-event-channels",
399 "%u", separate_tx_rx_irq);
400 if (err)
401 pr_debug("Error writing feature-split-event-channels\n");
402
403 /* Multi-queue support: This is an optional feature. */
404 err = xenbus_printf(XBT_NIL, dev->nodename,
405 "multi-queue-max-queues", "%u", xenvif_max_queues);
406 if (err)
407 pr_debug("Error writing multi-queue-max-queues\n");
408
409 err = xenbus_printf(XBT_NIL, dev->nodename,
410 "feature-ctrl-ring",
411 "%u", true);
412 if (err)
413 pr_debug("Error writing feature-ctrl-ring\n");
414
415 script = xenbus_read(XBT_NIL, dev->nodename, "script", NULL);
416 if (IS_ERR(script)) {
417 err = PTR_ERR(script);
418 xenbus_dev_fatal(dev, err, "reading script");
419 goto fail;
420 }
421
422 be->hotplug_script = script;
423
424
425 /* This kicks hotplug scripts, so do it immediately. */
426 err = backend_create_xenvif(be);
427 if (err)
428 goto fail;
429
430 return 0;
431
432abort_transaction:
433 xenbus_transaction_end(xbt, 1);
434 xenbus_dev_fatal(dev, err, "%s", message);
435fail:
436 pr_debug("failed\n");
437 netback_remove(dev);
438 return err;
439}
440
441
442/*
443 * Handle the creation of the hotplug script environment. We add the script
444 * and vif variables to the environment, for the benefit of the vif-* hotplug
445 * scripts.
446 */
447static int netback_uevent(struct xenbus_device *xdev,
448 struct kobj_uevent_env *env)
449{
450 struct backend_info *be = dev_get_drvdata(&xdev->dev);
451
452 if (!be)
453 return 0;
454
455 if (add_uevent_var(env, "script=%s", be->hotplug_script))
456 return -ENOMEM;
457
458 if (!be->vif)
459 return 0;
460
461 return add_uevent_var(env, "vif=%s", be->vif->dev->name);
462}
463
464
465static int backend_create_xenvif(struct backend_info *be)
466{
467 int err;
468 long handle;
469 struct xenbus_device *dev = be->dev;
470 struct xenvif *vif;
471
472 if (be->vif != NULL)
473 return 0;
474
475 err = xenbus_scanf(XBT_NIL, dev->nodename, "handle", "%li", &handle);
476 if (err != 1) {
477 xenbus_dev_fatal(dev, err, "reading handle");
478 return (err < 0) ? err : -EINVAL;
479 }
480
481 vif = xenvif_alloc(&dev->dev, dev->otherend_id, handle);
482 if (IS_ERR(vif)) {
483 err = PTR_ERR(vif);
484 xenbus_dev_fatal(dev, err, "creating interface");
485 return err;
486 }
487 be->vif = vif;
488
489 kobject_uevent(&dev->dev.kobj, KOBJ_ONLINE);
490 return 0;
491}
492
493static void backend_disconnect(struct backend_info *be)
494{
495 if (be->vif) {
496 unsigned int queue_index;
497
498 xen_unregister_watchers(be->vif);
499#ifdef CONFIG_DEBUG_FS
500 xenvif_debugfs_delif(be->vif);
501#endif /* CONFIG_DEBUG_FS */
502 xenvif_disconnect_data(be->vif);
503 for (queue_index = 0; queue_index < be->vif->num_queues; ++queue_index)
504 xenvif_deinit_queue(&be->vif->queues[queue_index]);
505
506 spin_lock(&be->vif->lock);
507 vfree(be->vif->queues);
508 be->vif->num_queues = 0;
509 be->vif->queues = NULL;
510 spin_unlock(&be->vif->lock);
511
512 xenvif_disconnect_ctrl(be->vif);
513 }
514}
515
516static void backend_connect(struct backend_info *be)
517{
518 if (be->vif)
519 connect(be);
520}
521
522static inline void backend_switch_state(struct backend_info *be,
523 enum xenbus_state state)
524{
525 struct xenbus_device *dev = be->dev;
526
527 pr_debug("%s -> %s\n", dev->nodename, xenbus_strstate(state));
528 be->state = state;
529
530 /* If we are waiting for a hotplug script then defer the
531 * actual xenbus state change.
532 */
533 if (!be->have_hotplug_status_watch)
534 xenbus_switch_state(dev, state);
535}
536
537/* Handle backend state transitions:
538 *
539 * The backend state starts in Initialising and the following transitions are
540 * allowed.
541 *
542 * Initialising -> InitWait -> Connected
543 * \
544 * \ ^ \ |
545 * \ | \ |
546 * \ | \ |
547 * \ | \ |
548 * \ | \ |
549 * \ | \ |
550 * V | V V
551 *
552 * Closed <-> Closing
553 *
554 * The state argument specifies the eventual state of the backend and the
555 * function transitions to that state via the shortest path.
556 */
557static void set_backend_state(struct backend_info *be,
558 enum xenbus_state state)
559{
560 while (be->state != state) {
561 switch (be->state) {
562 case XenbusStateInitialising:
563 switch (state) {
564 case XenbusStateInitWait:
565 case XenbusStateConnected:
566 case XenbusStateClosing:
567 backend_switch_state(be, XenbusStateInitWait);
568 break;
569 case XenbusStateClosed:
570 backend_switch_state(be, XenbusStateClosed);
571 break;
572 default:
573 BUG();
574 }
575 break;
576 case XenbusStateClosed:
577 switch (state) {
578 case XenbusStateInitWait:
579 case XenbusStateConnected:
580 backend_switch_state(be, XenbusStateInitWait);
581 break;
582 case XenbusStateClosing:
583 backend_switch_state(be, XenbusStateClosing);
584 break;
585 default:
586 BUG();
587 }
588 break;
589 case XenbusStateInitWait:
590 switch (state) {
591 case XenbusStateConnected:
592 backend_connect(be);
593 backend_switch_state(be, XenbusStateConnected);
594 break;
595 case XenbusStateClosing:
596 case XenbusStateClosed:
597 backend_switch_state(be, XenbusStateClosing);
598 break;
599 default:
600 BUG();
601 }
602 break;
603 case XenbusStateConnected:
604 switch (state) {
605 case XenbusStateInitWait:
606 case XenbusStateClosing:
607 case XenbusStateClosed:
608 backend_disconnect(be);
609 backend_switch_state(be, XenbusStateClosing);
610 break;
611 default:
612 BUG();
613 }
614 break;
615 case XenbusStateClosing:
616 switch (state) {
617 case XenbusStateInitWait:
618 case XenbusStateConnected:
619 case XenbusStateClosed:
620 backend_switch_state(be, XenbusStateClosed);
621 break;
622 default:
623 BUG();
624 }
625 break;
626 default:
627 BUG();
628 }
629 }
630}
631
632/**
633 * Callback received when the frontend's state changes.
634 */
635static void frontend_changed(struct xenbus_device *dev,
636 enum xenbus_state frontend_state)
637{
638 struct backend_info *be = dev_get_drvdata(&dev->dev);
639
640 pr_debug("%s -> %s\n", dev->otherend, xenbus_strstate(frontend_state));
641
642 be->frontend_state = frontend_state;
643
644 switch (frontend_state) {
645 case XenbusStateInitialising:
646 set_backend_state(be, XenbusStateInitWait);
647 break;
648
649 case XenbusStateInitialised:
650 break;
651
652 case XenbusStateConnected:
653 set_backend_state(be, XenbusStateConnected);
654 break;
655
656 case XenbusStateClosing:
657 set_backend_state(be, XenbusStateClosing);
658 break;
659
660 case XenbusStateClosed:
661 set_backend_state(be, XenbusStateClosed);
662 if (xenbus_dev_is_online(dev))
663 break;
664 /* fall through if not online */
665 case XenbusStateUnknown:
666 set_backend_state(be, XenbusStateClosed);
667 device_unregister(&dev->dev);
668 break;
669
670 default:
671 xenbus_dev_fatal(dev, -EINVAL, "saw state %d at frontend",
672 frontend_state);
673 break;
674 }
675}
676
677
678static void xen_net_read_rate(struct xenbus_device *dev,
679 unsigned long *bytes, unsigned long *usec)
680{
681 char *s, *e;
682 unsigned long b, u;
683 char *ratestr;
684
685 /* Default to unlimited bandwidth. */
686 *bytes = ~0UL;
687 *usec = 0;
688
689 ratestr = xenbus_read(XBT_NIL, dev->nodename, "rate", NULL);
690 if (IS_ERR(ratestr))
691 return;
692
693 s = ratestr;
694 b = simple_strtoul(s, &e, 10);
695 if ((s == e) || (*e != ','))
696 goto fail;
697
698 s = e + 1;
699 u = simple_strtoul(s, &e, 10);
700 if ((s == e) || (*e != '\0'))
701 goto fail;
702
703 *bytes = b;
704 *usec = u;
705
706 kfree(ratestr);
707 return;
708
709 fail:
710 pr_warn("Failed to parse network rate limit. Traffic unlimited.\n");
711 kfree(ratestr);
712}
713
714static int xen_net_read_mac(struct xenbus_device *dev, u8 mac[])
715{
716 char *s, *e, *macstr;
717 int i;
718
719 macstr = s = xenbus_read(XBT_NIL, dev->nodename, "mac", NULL);
720 if (IS_ERR(macstr))
721 return PTR_ERR(macstr);
722
723 for (i = 0; i < ETH_ALEN; i++) {
724 mac[i] = simple_strtoul(s, &e, 16);
725 if ((s == e) || (*e != ((i == ETH_ALEN-1) ? '\0' : ':'))) {
726 kfree(macstr);
727 return -ENOENT;
728 }
729 s = e+1;
730 }
731
732 kfree(macstr);
733 return 0;
734}
735
736static void xen_net_rate_changed(struct xenbus_watch *watch,
737 const char **vec, unsigned int len)
738{
739 struct xenvif *vif = container_of(watch, struct xenvif, credit_watch);
740 struct xenbus_device *dev = xenvif_to_xenbus_device(vif);
741 unsigned long credit_bytes;
742 unsigned long credit_usec;
743 unsigned int queue_index;
744
745 xen_net_read_rate(dev, &credit_bytes, &credit_usec);
746 for (queue_index = 0; queue_index < vif->num_queues; queue_index++) {
747 struct xenvif_queue *queue = &vif->queues[queue_index];
748
749 queue->credit_bytes = credit_bytes;
750 queue->credit_usec = credit_usec;
751 if (!mod_timer_pending(&queue->credit_timeout, jiffies) &&
752 queue->remaining_credit > queue->credit_bytes) {
753 queue->remaining_credit = queue->credit_bytes;
754 }
755 }
756}
757
758static int xen_register_credit_watch(struct xenbus_device *dev,
759 struct xenvif *vif)
760{
761 int err = 0;
762 char *node;
763 unsigned maxlen = strlen(dev->nodename) + sizeof("/rate");
764
765 if (vif->credit_watch.node)
766 return -EADDRINUSE;
767
768 node = kmalloc(maxlen, GFP_KERNEL);
769 if (!node)
770 return -ENOMEM;
771 snprintf(node, maxlen, "%s/rate", dev->nodename);
772 vif->credit_watch.node = node;
773 vif->credit_watch.callback = xen_net_rate_changed;
774 err = register_xenbus_watch(&vif->credit_watch);
775 if (err) {
776 pr_err("Failed to set watcher %s\n", vif->credit_watch.node);
777 kfree(node);
778 vif->credit_watch.node = NULL;
779 vif->credit_watch.callback = NULL;
780 }
781 return err;
782}
783
784static void xen_unregister_credit_watch(struct xenvif *vif)
785{
786 if (vif->credit_watch.node) {
787 unregister_xenbus_watch(&vif->credit_watch);
788 kfree(vif->credit_watch.node);
789 vif->credit_watch.node = NULL;
790 }
791}
792
793static void xen_mcast_ctrl_changed(struct xenbus_watch *watch,
794 const char **vec, unsigned int len)
795{
796 struct xenvif *vif = container_of(watch, struct xenvif,
797 mcast_ctrl_watch);
798 struct xenbus_device *dev = xenvif_to_xenbus_device(vif);
799
800 vif->multicast_control = !!xenbus_read_unsigned(dev->otherend,
801 "request-multicast-control", 0);
802}
803
804static int xen_register_mcast_ctrl_watch(struct xenbus_device *dev,
805 struct xenvif *vif)
806{
807 int err = 0;
808 char *node;
809 unsigned maxlen = strlen(dev->otherend) +
810 sizeof("/request-multicast-control");
811
812 if (vif->mcast_ctrl_watch.node) {
813 pr_err_ratelimited("Watch is already registered\n");
814 return -EADDRINUSE;
815 }
816
817 node = kmalloc(maxlen, GFP_KERNEL);
818 if (!node) {
819 pr_err("Failed to allocate memory for watch\n");
820 return -ENOMEM;
821 }
822 snprintf(node, maxlen, "%s/request-multicast-control",
823 dev->otherend);
824 vif->mcast_ctrl_watch.node = node;
825 vif->mcast_ctrl_watch.callback = xen_mcast_ctrl_changed;
826 err = register_xenbus_watch(&vif->mcast_ctrl_watch);
827 if (err) {
828 pr_err("Failed to set watcher %s\n",
829 vif->mcast_ctrl_watch.node);
830 kfree(node);
831 vif->mcast_ctrl_watch.node = NULL;
832 vif->mcast_ctrl_watch.callback = NULL;
833 }
834 return err;
835}
836
837static void xen_unregister_mcast_ctrl_watch(struct xenvif *vif)
838{
839 if (vif->mcast_ctrl_watch.node) {
840 unregister_xenbus_watch(&vif->mcast_ctrl_watch);
841 kfree(vif->mcast_ctrl_watch.node);
842 vif->mcast_ctrl_watch.node = NULL;
843 }
844}
845
846static void xen_register_watchers(struct xenbus_device *dev,
847 struct xenvif *vif)
848{
849 xen_register_credit_watch(dev, vif);
850 xen_register_mcast_ctrl_watch(dev, vif);
851}
852
853static void xen_unregister_watchers(struct xenvif *vif)
854{
855 xen_unregister_mcast_ctrl_watch(vif);
856 xen_unregister_credit_watch(vif);
857}
858
859static void unregister_hotplug_status_watch(struct backend_info *be)
860{
861 if (be->have_hotplug_status_watch) {
862 unregister_xenbus_watch(&be->hotplug_status_watch);
863 kfree(be->hotplug_status_watch.node);
864 }
865 be->have_hotplug_status_watch = 0;
866}
867
868static void hotplug_status_changed(struct xenbus_watch *watch,
869 const char **vec,
870 unsigned int vec_size)
871{
872 struct backend_info *be = container_of(watch,
873 struct backend_info,
874 hotplug_status_watch);
875 char *str;
876 unsigned int len;
877
878 str = xenbus_read(XBT_NIL, be->dev->nodename, "hotplug-status", &len);
879 if (IS_ERR(str))
880 return;
881 if (len == sizeof("connected")-1 && !memcmp(str, "connected", len)) {
882 /* Complete any pending state change */
883 xenbus_switch_state(be->dev, be->state);
884
885 /* Not interested in this watch anymore. */
886 unregister_hotplug_status_watch(be);
887 }
888 kfree(str);
889}
890
891static int connect_ctrl_ring(struct backend_info *be)
892{
893 struct xenbus_device *dev = be->dev;
894 struct xenvif *vif = be->vif;
895 unsigned int val;
896 grant_ref_t ring_ref;
897 unsigned int evtchn;
898 int err;
899
900 err = xenbus_scanf(XBT_NIL, dev->otherend,
901 "ctrl-ring-ref", "%u", &val);
902 if (err < 0)
903 goto done; /* The frontend does not have a control ring */
904
905 ring_ref = val;
906
907 err = xenbus_scanf(XBT_NIL, dev->otherend,
908 "event-channel-ctrl", "%u", &val);
909 if (err < 0) {
910 xenbus_dev_fatal(dev, err,
911 "reading %s/event-channel-ctrl",
912 dev->otherend);
913 goto fail;
914 }
915
916 evtchn = val;
917
918 err = xenvif_connect_ctrl(vif, ring_ref, evtchn);
919 if (err) {
920 xenbus_dev_fatal(dev, err,
921 "mapping shared-frame %u port %u",
922 ring_ref, evtchn);
923 goto fail;
924 }
925
926done:
927 return 0;
928
929fail:
930 return err;
931}
932
933static void connect(struct backend_info *be)
934{
935 int err;
936 struct xenbus_device *dev = be->dev;
937 unsigned long credit_bytes, credit_usec;
938 unsigned int queue_index;
939 unsigned int requested_num_queues;
940 struct xenvif_queue *queue;
941
942 /* Check whether the frontend requested multiple queues
943 * and read the number requested.
944 */
945 requested_num_queues = xenbus_read_unsigned(dev->otherend,
946 "multi-queue-num-queues", 1);
947 if (requested_num_queues > xenvif_max_queues) {
948 /* buggy or malicious guest */
949 xenbus_dev_fatal(dev, -EINVAL,
950 "guest requested %u queues, exceeding the maximum of %u.",
951 requested_num_queues, xenvif_max_queues);
952 return;
953 }
954
955 err = xen_net_read_mac(dev, be->vif->fe_dev_addr);
956 if (err) {
957 xenbus_dev_fatal(dev, err, "parsing %s/mac", dev->nodename);
958 return;
959 }
960
961 xen_net_read_rate(dev, &credit_bytes, &credit_usec);
962 xen_unregister_watchers(be->vif);
963 xen_register_watchers(dev, be->vif);
964 read_xenbus_vif_flags(be);
965
966 err = connect_ctrl_ring(be);
967 if (err) {
968 xenbus_dev_fatal(dev, err, "connecting control ring");
969 return;
970 }
971
972 /* Use the number of queues requested by the frontend */
973 be->vif->queues = vzalloc(requested_num_queues *
974 sizeof(struct xenvif_queue));
975 if (!be->vif->queues) {
976 xenbus_dev_fatal(dev, -ENOMEM,
977 "allocating queues");
978 return;
979 }
980
981 be->vif->num_queues = requested_num_queues;
982 be->vif->stalled_queues = requested_num_queues;
983
984 for (queue_index = 0; queue_index < requested_num_queues; ++queue_index) {
985 queue = &be->vif->queues[queue_index];
986 queue->vif = be->vif;
987 queue->id = queue_index;
988 snprintf(queue->name, sizeof(queue->name), "%s-q%u",
989 be->vif->dev->name, queue->id);
990
991 err = xenvif_init_queue(queue);
992 if (err) {
993 /* xenvif_init_queue() cleans up after itself on
994 * failure, but we need to clean up any previously
995 * initialised queues. Set num_queues to i so that
996 * earlier queues can be destroyed using the regular
997 * disconnect logic.
998 */
999 be->vif->num_queues = queue_index;
1000 goto err;
1001 }
1002
1003 queue->credit_bytes = credit_bytes;
1004 queue->remaining_credit = credit_bytes;
1005 queue->credit_usec = credit_usec;
1006
1007 err = connect_data_rings(be, queue);
1008 if (err) {
1009 /* connect_data_rings() cleans up after itself on
1010 * failure, but we need to clean up after
1011 * xenvif_init_queue() here, and also clean up any
1012 * previously initialised queues.
1013 */
1014 xenvif_deinit_queue(queue);
1015 be->vif->num_queues = queue_index;
1016 goto err;
1017 }
1018 }
1019
1020#ifdef CONFIG_DEBUG_FS
1021 xenvif_debugfs_addif(be->vif);
1022#endif /* CONFIG_DEBUG_FS */
1023
1024 /* Initialisation completed, tell core driver the number of
1025 * active queues.
1026 */
1027 rtnl_lock();
1028 netif_set_real_num_tx_queues(be->vif->dev, requested_num_queues);
1029 netif_set_real_num_rx_queues(be->vif->dev, requested_num_queues);
1030 rtnl_unlock();
1031
1032 xenvif_carrier_on(be->vif);
1033
1034 unregister_hotplug_status_watch(be);
1035 err = xenbus_watch_pathfmt(dev, &be->hotplug_status_watch,
1036 hotplug_status_changed,
1037 "%s/%s", dev->nodename, "hotplug-status");
1038 if (!err)
1039 be->have_hotplug_status_watch = 1;
1040
1041 netif_tx_wake_all_queues(be->vif->dev);
1042
1043 return;
1044
1045err:
1046 if (be->vif->num_queues > 0)
1047 xenvif_disconnect_data(be->vif); /* Clean up existing queues */
1048 for (queue_index = 0; queue_index < be->vif->num_queues; ++queue_index)
1049 xenvif_deinit_queue(&be->vif->queues[queue_index]);
1050 vfree(be->vif->queues);
1051 be->vif->queues = NULL;
1052 be->vif->num_queues = 0;
1053 xenvif_disconnect_ctrl(be->vif);
1054 return;
1055}
1056
1057
1058static int connect_data_rings(struct backend_info *be,
1059 struct xenvif_queue *queue)
1060{
1061 struct xenbus_device *dev = be->dev;
1062 unsigned int num_queues = queue->vif->num_queues;
1063 unsigned long tx_ring_ref, rx_ring_ref;
1064 unsigned int tx_evtchn, rx_evtchn;
1065 int err;
1066 char *xspath;
1067 size_t xspathsize;
1068 const size_t xenstore_path_ext_size = 11; /* sufficient for "/queue-NNN" */
1069
1070 /* If the frontend requested 1 queue, or we have fallen back
1071 * to single queue due to lack of frontend support for multi-
1072 * queue, expect the remaining XenStore keys in the toplevel
1073 * directory. Otherwise, expect them in a subdirectory called
1074 * queue-N.
1075 */
1076 if (num_queues == 1) {
1077 xspath = kzalloc(strlen(dev->otherend) + 1, GFP_KERNEL);
1078 if (!xspath) {
1079 xenbus_dev_fatal(dev, -ENOMEM,
1080 "reading ring references");
1081 return -ENOMEM;
1082 }
1083 strcpy(xspath, dev->otherend);
1084 } else {
1085 xspathsize = strlen(dev->otherend) + xenstore_path_ext_size;
1086 xspath = kzalloc(xspathsize, GFP_KERNEL);
1087 if (!xspath) {
1088 xenbus_dev_fatal(dev, -ENOMEM,
1089 "reading ring references");
1090 return -ENOMEM;
1091 }
1092 snprintf(xspath, xspathsize, "%s/queue-%u", dev->otherend,
1093 queue->id);
1094 }
1095
1096 err = xenbus_gather(XBT_NIL, xspath,
1097 "tx-ring-ref", "%lu", &tx_ring_ref,
1098 "rx-ring-ref", "%lu", &rx_ring_ref, NULL);
1099 if (err) {
1100 xenbus_dev_fatal(dev, err,
1101 "reading %s/ring-ref",
1102 xspath);
1103 goto err;
1104 }
1105
1106 /* Try split event channels first, then single event channel. */
1107 err = xenbus_gather(XBT_NIL, xspath,
1108 "event-channel-tx", "%u", &tx_evtchn,
1109 "event-channel-rx", "%u", &rx_evtchn, NULL);
1110 if (err < 0) {
1111 err = xenbus_scanf(XBT_NIL, xspath,
1112 "event-channel", "%u", &tx_evtchn);
1113 if (err < 0) {
1114 xenbus_dev_fatal(dev, err,
1115 "reading %s/event-channel(-tx/rx)",
1116 xspath);
1117 goto err;
1118 }
1119 rx_evtchn = tx_evtchn;
1120 }
1121
1122 /* Map the shared frame, irq etc. */
1123 err = xenvif_connect_data(queue, tx_ring_ref, rx_ring_ref,
1124 tx_evtchn, rx_evtchn);
1125 if (err) {
1126 xenbus_dev_fatal(dev, err,
1127 "mapping shared-frames %lu/%lu port tx %u rx %u",
1128 tx_ring_ref, rx_ring_ref,
1129 tx_evtchn, rx_evtchn);
1130 goto err;
1131 }
1132
1133 err = 0;
1134err: /* Regular return falls through with err == 0 */
1135 kfree(xspath);
1136 return err;
1137}
1138
1139static int read_xenbus_vif_flags(struct backend_info *be)
1140{
1141 struct xenvif *vif = be->vif;
1142 struct xenbus_device *dev = be->dev;
1143 unsigned int rx_copy;
1144 int err;
1145
1146 err = xenbus_scanf(XBT_NIL, dev->otherend, "request-rx-copy", "%u",
1147 &rx_copy);
1148 if (err == -ENOENT) {
1149 err = 0;
1150 rx_copy = 0;
1151 }
1152 if (err < 0) {
1153 xenbus_dev_fatal(dev, err, "reading %s/request-rx-copy",
1154 dev->otherend);
1155 return err;
1156 }
1157 if (!rx_copy)
1158 return -EOPNOTSUPP;
1159
1160 if (!xenbus_read_unsigned(dev->otherend, "feature-rx-notify", 0)) {
1161 /* - Reduce drain timeout to poll more frequently for
1162 * Rx requests.
1163 * - Disable Rx stall detection.
1164 */
1165 be->vif->drain_timeout = msecs_to_jiffies(30);
1166 be->vif->stall_timeout = 0;
1167 }
1168
1169 vif->can_sg = !!xenbus_read_unsigned(dev->otherend, "feature-sg", 0);
1170
1171 vif->gso_mask = 0;
1172
1173 if (xenbus_read_unsigned(dev->otherend, "feature-gso-tcpv4", 0))
1174 vif->gso_mask |= GSO_BIT(TCPV4);
1175
1176 if (xenbus_read_unsigned(dev->otherend, "feature-gso-tcpv6", 0))
1177 vif->gso_mask |= GSO_BIT(TCPV6);
1178
1179 vif->ip_csum = !xenbus_read_unsigned(dev->otherend,
1180 "feature-no-csum-offload", 0);
1181
1182 vif->ipv6_csum = !!xenbus_read_unsigned(dev->otherend,
1183 "feature-ipv6-csum-offload", 0);
1184
1185 return 0;
1186}
1187
1188static const struct xenbus_device_id netback_ids[] = {
1189 { "vif" },
1190 { "" }
1191};
1192
1193static struct xenbus_driver netback_driver = {
1194 .ids = netback_ids,
1195 .probe = netback_probe,
1196 .remove = netback_remove,
1197 .uevent = netback_uevent,
1198 .otherend_changed = frontend_changed,
1199};
1200
1201int xenvif_xenbus_init(void)
1202{
1203 return xenbus_register_backend(&netback_driver);
1204}
1205
1206void xenvif_xenbus_fini(void)
1207{
1208 return xenbus_unregister_driver(&netback_driver);
1209}
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Xenbus code for netif backend
4 *
5 * Copyright (C) 2005 Rusty Russell <rusty@rustcorp.com.au>
6 * Copyright (C) 2005 XenSource Ltd
7*/
8
9#include "common.h"
10#include <linux/vmalloc.h>
11#include <linux/rtnetlink.h>
12
13static int connect_data_rings(struct backend_info *be,
14 struct xenvif_queue *queue);
15static void connect(struct backend_info *be);
16static int read_xenbus_vif_flags(struct backend_info *be);
17static int backend_create_xenvif(struct backend_info *be);
18static void unregister_hotplug_status_watch(struct backend_info *be);
19static void xen_unregister_watchers(struct xenvif *vif);
20static void set_backend_state(struct backend_info *be,
21 enum xenbus_state state);
22
23#ifdef CONFIG_DEBUG_FS
24struct dentry *xen_netback_dbg_root = NULL;
25
26static int xenvif_read_io_ring(struct seq_file *m, void *v)
27{
28 struct xenvif_queue *queue = m->private;
29 struct xen_netif_tx_back_ring *tx_ring = &queue->tx;
30 struct xen_netif_rx_back_ring *rx_ring = &queue->rx;
31 struct netdev_queue *dev_queue;
32
33 if (tx_ring->sring) {
34 struct xen_netif_tx_sring *sring = tx_ring->sring;
35
36 seq_printf(m, "Queue %d\nTX: nr_ents %u\n", queue->id,
37 tx_ring->nr_ents);
38 seq_printf(m, "req prod %u (%d) cons %u (%d) event %u (%d)\n",
39 sring->req_prod,
40 sring->req_prod - sring->rsp_prod,
41 tx_ring->req_cons,
42 tx_ring->req_cons - sring->rsp_prod,
43 sring->req_event,
44 sring->req_event - sring->rsp_prod);
45 seq_printf(m, "rsp prod %u (base) pvt %u (%d) event %u (%d)\n",
46 sring->rsp_prod,
47 tx_ring->rsp_prod_pvt,
48 tx_ring->rsp_prod_pvt - sring->rsp_prod,
49 sring->rsp_event,
50 sring->rsp_event - sring->rsp_prod);
51 seq_printf(m, "pending prod %u pending cons %u nr_pending_reqs %u\n",
52 queue->pending_prod,
53 queue->pending_cons,
54 nr_pending_reqs(queue));
55 seq_printf(m, "dealloc prod %u dealloc cons %u dealloc_queue %u\n\n",
56 queue->dealloc_prod,
57 queue->dealloc_cons,
58 queue->dealloc_prod - queue->dealloc_cons);
59 }
60
61 if (rx_ring->sring) {
62 struct xen_netif_rx_sring *sring = rx_ring->sring;
63
64 seq_printf(m, "RX: nr_ents %u\n", rx_ring->nr_ents);
65 seq_printf(m, "req prod %u (%d) cons %u (%d) event %u (%d)\n",
66 sring->req_prod,
67 sring->req_prod - sring->rsp_prod,
68 rx_ring->req_cons,
69 rx_ring->req_cons - sring->rsp_prod,
70 sring->req_event,
71 sring->req_event - sring->rsp_prod);
72 seq_printf(m, "rsp prod %u (base) pvt %u (%d) event %u (%d)\n\n",
73 sring->rsp_prod,
74 rx_ring->rsp_prod_pvt,
75 rx_ring->rsp_prod_pvt - sring->rsp_prod,
76 sring->rsp_event,
77 sring->rsp_event - sring->rsp_prod);
78 }
79
80 seq_printf(m, "NAPI state: %lx NAPI weight: %d TX queue len %u\n"
81 "Credit timer_pending: %d, credit: %lu, usec: %lu\n"
82 "remaining: %lu, expires: %lu, now: %lu\n",
83 queue->napi.state, queue->napi.weight,
84 skb_queue_len(&queue->tx_queue),
85 timer_pending(&queue->credit_timeout),
86 queue->credit_bytes,
87 queue->credit_usec,
88 queue->remaining_credit,
89 queue->credit_timeout.expires,
90 jiffies);
91
92 dev_queue = netdev_get_tx_queue(queue->vif->dev, queue->id);
93
94 seq_printf(m, "\nRx internal queue: len %u max %u pkts %u %s\n",
95 queue->rx_queue_len, queue->rx_queue_max,
96 skb_queue_len(&queue->rx_queue),
97 netif_tx_queue_stopped(dev_queue) ? "stopped" : "running");
98
99 return 0;
100}
101
102#define XENVIF_KICK_STR "kick"
103#define BUFFER_SIZE 32
104
105static ssize_t
106xenvif_write_io_ring(struct file *filp, const char __user *buf, size_t count,
107 loff_t *ppos)
108{
109 struct xenvif_queue *queue =
110 ((struct seq_file *)filp->private_data)->private;
111 int len;
112 char write[BUFFER_SIZE];
113
114 /* don't allow partial writes and check the length */
115 if (*ppos != 0)
116 return 0;
117 if (count >= sizeof(write))
118 return -ENOSPC;
119
120 len = simple_write_to_buffer(write,
121 sizeof(write) - 1,
122 ppos,
123 buf,
124 count);
125 if (len < 0)
126 return len;
127
128 write[len] = '\0';
129
130 if (!strncmp(write, XENVIF_KICK_STR, sizeof(XENVIF_KICK_STR) - 1))
131 xenvif_interrupt(0, (void *)queue);
132 else {
133 pr_warn("Unknown command to io_ring_q%d. Available: kick\n",
134 queue->id);
135 count = -EINVAL;
136 }
137 return count;
138}
139
140static int xenvif_io_ring_open(struct inode *inode, struct file *filp)
141{
142 int ret;
143 void *queue = NULL;
144
145 if (inode->i_private)
146 queue = inode->i_private;
147 ret = single_open(filp, xenvif_read_io_ring, queue);
148 filp->f_mode |= FMODE_PWRITE;
149 return ret;
150}
151
152static const struct file_operations xenvif_dbg_io_ring_ops_fops = {
153 .owner = THIS_MODULE,
154 .open = xenvif_io_ring_open,
155 .read = seq_read,
156 .llseek = seq_lseek,
157 .release = single_release,
158 .write = xenvif_write_io_ring,
159};
160
161static int xenvif_ctrl_show(struct seq_file *m, void *v)
162{
163 struct xenvif *vif = m->private;
164
165 xenvif_dump_hash_info(vif, m);
166
167 return 0;
168}
169DEFINE_SHOW_ATTRIBUTE(xenvif_ctrl);
170
171static void xenvif_debugfs_addif(struct xenvif *vif)
172{
173 int i;
174
175 vif->xenvif_dbg_root = debugfs_create_dir(vif->dev->name,
176 xen_netback_dbg_root);
177 for (i = 0; i < vif->num_queues; ++i) {
178 char filename[sizeof("io_ring_q") + 4];
179
180 snprintf(filename, sizeof(filename), "io_ring_q%d", i);
181 debugfs_create_file(filename, 0600, vif->xenvif_dbg_root,
182 &vif->queues[i],
183 &xenvif_dbg_io_ring_ops_fops);
184 }
185
186 if (vif->ctrl_irq)
187 debugfs_create_file("ctrl", 0400, vif->xenvif_dbg_root, vif,
188 &xenvif_ctrl_fops);
189}
190
191static void xenvif_debugfs_delif(struct xenvif *vif)
192{
193 debugfs_remove_recursive(vif->xenvif_dbg_root);
194 vif->xenvif_dbg_root = NULL;
195}
196#endif /* CONFIG_DEBUG_FS */
197
198static int netback_remove(struct xenbus_device *dev)
199{
200 struct backend_info *be = dev_get_drvdata(&dev->dev);
201
202 set_backend_state(be, XenbusStateClosed);
203
204 unregister_hotplug_status_watch(be);
205 if (be->vif) {
206 kobject_uevent(&dev->dev.kobj, KOBJ_OFFLINE);
207 xen_unregister_watchers(be->vif);
208 xenbus_rm(XBT_NIL, dev->nodename, "hotplug-status");
209 xenvif_free(be->vif);
210 be->vif = NULL;
211 }
212 kfree(be->hotplug_script);
213 kfree(be);
214 dev_set_drvdata(&dev->dev, NULL);
215 return 0;
216}
217
218
219/**
220 * Entry point to this code when a new device is created. Allocate the basic
221 * structures and switch to InitWait.
222 */
223static int netback_probe(struct xenbus_device *dev,
224 const struct xenbus_device_id *id)
225{
226 const char *message;
227 struct xenbus_transaction xbt;
228 int err;
229 int sg;
230 const char *script;
231 struct backend_info *be = kzalloc(sizeof(struct backend_info),
232 GFP_KERNEL);
233 if (!be) {
234 xenbus_dev_fatal(dev, -ENOMEM,
235 "allocating backend structure");
236 return -ENOMEM;
237 }
238
239 be->dev = dev;
240 dev_set_drvdata(&dev->dev, be);
241
242 be->state = XenbusStateInitialising;
243 err = xenbus_switch_state(dev, XenbusStateInitialising);
244 if (err)
245 goto fail;
246
247 sg = 1;
248
249 do {
250 err = xenbus_transaction_start(&xbt);
251 if (err) {
252 xenbus_dev_fatal(dev, err, "starting transaction");
253 goto fail;
254 }
255
256 err = xenbus_printf(xbt, dev->nodename, "feature-sg", "%d", sg);
257 if (err) {
258 message = "writing feature-sg";
259 goto abort_transaction;
260 }
261
262 err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv4",
263 "%d", sg);
264 if (err) {
265 message = "writing feature-gso-tcpv4";
266 goto abort_transaction;
267 }
268
269 err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv6",
270 "%d", sg);
271 if (err) {
272 message = "writing feature-gso-tcpv6";
273 goto abort_transaction;
274 }
275
276 /* We support partial checksum setup for IPv6 packets */
277 err = xenbus_printf(xbt, dev->nodename,
278 "feature-ipv6-csum-offload",
279 "%d", 1);
280 if (err) {
281 message = "writing feature-ipv6-csum-offload";
282 goto abort_transaction;
283 }
284
285 /* We support rx-copy path. */
286 err = xenbus_printf(xbt, dev->nodename,
287 "feature-rx-copy", "%d", 1);
288 if (err) {
289 message = "writing feature-rx-copy";
290 goto abort_transaction;
291 }
292
293 /*
294 * We don't support rx-flip path (except old guests who don't
295 * grok this feature flag).
296 */
297 err = xenbus_printf(xbt, dev->nodename,
298 "feature-rx-flip", "%d", 0);
299 if (err) {
300 message = "writing feature-rx-flip";
301 goto abort_transaction;
302 }
303
304 /* We support dynamic multicast-control. */
305 err = xenbus_printf(xbt, dev->nodename,
306 "feature-multicast-control", "%d", 1);
307 if (err) {
308 message = "writing feature-multicast-control";
309 goto abort_transaction;
310 }
311
312 err = xenbus_printf(xbt, dev->nodename,
313 "feature-dynamic-multicast-control",
314 "%d", 1);
315 if (err) {
316 message = "writing feature-dynamic-multicast-control";
317 goto abort_transaction;
318 }
319
320 err = xenbus_transaction_end(xbt, 0);
321 } while (err == -EAGAIN);
322
323 if (err) {
324 xenbus_dev_fatal(dev, err, "completing transaction");
325 goto fail;
326 }
327
328 /*
329 * Split event channels support, this is optional so it is not
330 * put inside the above loop.
331 */
332 err = xenbus_printf(XBT_NIL, dev->nodename,
333 "feature-split-event-channels",
334 "%u", separate_tx_rx_irq);
335 if (err)
336 pr_debug("Error writing feature-split-event-channels\n");
337
338 /* Multi-queue support: This is an optional feature. */
339 err = xenbus_printf(XBT_NIL, dev->nodename,
340 "multi-queue-max-queues", "%u", xenvif_max_queues);
341 if (err)
342 pr_debug("Error writing multi-queue-max-queues\n");
343
344 err = xenbus_printf(XBT_NIL, dev->nodename,
345 "feature-ctrl-ring",
346 "%u", true);
347 if (err)
348 pr_debug("Error writing feature-ctrl-ring\n");
349
350 script = xenbus_read(XBT_NIL, dev->nodename, "script", NULL);
351 if (IS_ERR(script)) {
352 err = PTR_ERR(script);
353 xenbus_dev_fatal(dev, err, "reading script");
354 goto fail;
355 }
356
357 be->hotplug_script = script;
358
359
360 /* This kicks hotplug scripts, so do it immediately. */
361 err = backend_create_xenvif(be);
362 if (err)
363 goto fail;
364
365 return 0;
366
367abort_transaction:
368 xenbus_transaction_end(xbt, 1);
369 xenbus_dev_fatal(dev, err, "%s", message);
370fail:
371 pr_debug("failed\n");
372 netback_remove(dev);
373 return err;
374}
375
376
377/*
378 * Handle the creation of the hotplug script environment. We add the script
379 * and vif variables to the environment, for the benefit of the vif-* hotplug
380 * scripts.
381 */
382static int netback_uevent(struct xenbus_device *xdev,
383 struct kobj_uevent_env *env)
384{
385 struct backend_info *be = dev_get_drvdata(&xdev->dev);
386
387 if (!be)
388 return 0;
389
390 if (add_uevent_var(env, "script=%s", be->hotplug_script))
391 return -ENOMEM;
392
393 if (!be->vif)
394 return 0;
395
396 return add_uevent_var(env, "vif=%s", be->vif->dev->name);
397}
398
399
400static int backend_create_xenvif(struct backend_info *be)
401{
402 int err;
403 long handle;
404 struct xenbus_device *dev = be->dev;
405 struct xenvif *vif;
406
407 if (be->vif != NULL)
408 return 0;
409
410 err = xenbus_scanf(XBT_NIL, dev->nodename, "handle", "%li", &handle);
411 if (err != 1) {
412 xenbus_dev_fatal(dev, err, "reading handle");
413 return (err < 0) ? err : -EINVAL;
414 }
415
416 vif = xenvif_alloc(&dev->dev, dev->otherend_id, handle);
417 if (IS_ERR(vif)) {
418 err = PTR_ERR(vif);
419 xenbus_dev_fatal(dev, err, "creating interface");
420 return err;
421 }
422 be->vif = vif;
423 vif->be = be;
424
425 kobject_uevent(&dev->dev.kobj, KOBJ_ONLINE);
426 return 0;
427}
428
429static void backend_disconnect(struct backend_info *be)
430{
431 struct xenvif *vif = be->vif;
432
433 if (vif) {
434 unsigned int num_queues = vif->num_queues;
435 unsigned int queue_index;
436
437 xen_unregister_watchers(vif);
438#ifdef CONFIG_DEBUG_FS
439 xenvif_debugfs_delif(vif);
440#endif /* CONFIG_DEBUG_FS */
441 xenvif_disconnect_data(vif);
442
443 /* At this point some of the handlers may still be active
444 * so we need to have additional synchronization here.
445 */
446 vif->num_queues = 0;
447 synchronize_net();
448
449 for (queue_index = 0; queue_index < num_queues; ++queue_index)
450 xenvif_deinit_queue(&vif->queues[queue_index]);
451
452 vfree(vif->queues);
453 vif->queues = NULL;
454
455 xenvif_disconnect_ctrl(vif);
456 }
457}
458
459static void backend_connect(struct backend_info *be)
460{
461 if (be->vif)
462 connect(be);
463}
464
465static inline void backend_switch_state(struct backend_info *be,
466 enum xenbus_state state)
467{
468 struct xenbus_device *dev = be->dev;
469
470 pr_debug("%s -> %s\n", dev->nodename, xenbus_strstate(state));
471 be->state = state;
472
473 /* If we are waiting for a hotplug script then defer the
474 * actual xenbus state change.
475 */
476 if (!be->have_hotplug_status_watch)
477 xenbus_switch_state(dev, state);
478}
479
480/* Handle backend state transitions:
481 *
482 * The backend state starts in Initialising and the following transitions are
483 * allowed.
484 *
485 * Initialising -> InitWait -> Connected
486 * \
487 * \ ^ \ |
488 * \ | \ |
489 * \ | \ |
490 * \ | \ |
491 * \ | \ |
492 * \ | \ |
493 * V | V V
494 *
495 * Closed <-> Closing
496 *
497 * The state argument specifies the eventual state of the backend and the
498 * function transitions to that state via the shortest path.
499 */
500static void set_backend_state(struct backend_info *be,
501 enum xenbus_state state)
502{
503 while (be->state != state) {
504 switch (be->state) {
505 case XenbusStateInitialising:
506 switch (state) {
507 case XenbusStateInitWait:
508 case XenbusStateConnected:
509 case XenbusStateClosing:
510 backend_switch_state(be, XenbusStateInitWait);
511 break;
512 case XenbusStateClosed:
513 backend_switch_state(be, XenbusStateClosed);
514 break;
515 default:
516 BUG();
517 }
518 break;
519 case XenbusStateClosed:
520 switch (state) {
521 case XenbusStateInitWait:
522 case XenbusStateConnected:
523 backend_switch_state(be, XenbusStateInitWait);
524 break;
525 case XenbusStateClosing:
526 backend_switch_state(be, XenbusStateClosing);
527 break;
528 default:
529 BUG();
530 }
531 break;
532 case XenbusStateInitWait:
533 switch (state) {
534 case XenbusStateConnected:
535 backend_connect(be);
536 backend_switch_state(be, XenbusStateConnected);
537 break;
538 case XenbusStateClosing:
539 case XenbusStateClosed:
540 backend_switch_state(be, XenbusStateClosing);
541 break;
542 default:
543 BUG();
544 }
545 break;
546 case XenbusStateConnected:
547 switch (state) {
548 case XenbusStateInitWait:
549 case XenbusStateClosing:
550 case XenbusStateClosed:
551 backend_disconnect(be);
552 backend_switch_state(be, XenbusStateClosing);
553 break;
554 default:
555 BUG();
556 }
557 break;
558 case XenbusStateClosing:
559 switch (state) {
560 case XenbusStateInitWait:
561 case XenbusStateConnected:
562 case XenbusStateClosed:
563 backend_switch_state(be, XenbusStateClosed);
564 break;
565 default:
566 BUG();
567 }
568 break;
569 default:
570 BUG();
571 }
572 }
573}
574
575/**
576 * Callback received when the frontend's state changes.
577 */
578static void frontend_changed(struct xenbus_device *dev,
579 enum xenbus_state frontend_state)
580{
581 struct backend_info *be = dev_get_drvdata(&dev->dev);
582
583 pr_debug("%s -> %s\n", dev->otherend, xenbus_strstate(frontend_state));
584
585 be->frontend_state = frontend_state;
586
587 switch (frontend_state) {
588 case XenbusStateInitialising:
589 set_backend_state(be, XenbusStateInitWait);
590 break;
591
592 case XenbusStateInitialised:
593 break;
594
595 case XenbusStateConnected:
596 set_backend_state(be, XenbusStateConnected);
597 break;
598
599 case XenbusStateClosing:
600 set_backend_state(be, XenbusStateClosing);
601 break;
602
603 case XenbusStateClosed:
604 set_backend_state(be, XenbusStateClosed);
605 if (xenbus_dev_is_online(dev))
606 break;
607 /* fall through - if not online */
608 case XenbusStateUnknown:
609 set_backend_state(be, XenbusStateClosed);
610 device_unregister(&dev->dev);
611 break;
612
613 default:
614 xenbus_dev_fatal(dev, -EINVAL, "saw state %d at frontend",
615 frontend_state);
616 break;
617 }
618}
619
620
621static void xen_net_read_rate(struct xenbus_device *dev,
622 unsigned long *bytes, unsigned long *usec)
623{
624 char *s, *e;
625 unsigned long b, u;
626 char *ratestr;
627
628 /* Default to unlimited bandwidth. */
629 *bytes = ~0UL;
630 *usec = 0;
631
632 ratestr = xenbus_read(XBT_NIL, dev->nodename, "rate", NULL);
633 if (IS_ERR(ratestr))
634 return;
635
636 s = ratestr;
637 b = simple_strtoul(s, &e, 10);
638 if ((s == e) || (*e != ','))
639 goto fail;
640
641 s = e + 1;
642 u = simple_strtoul(s, &e, 10);
643 if ((s == e) || (*e != '\0'))
644 goto fail;
645
646 *bytes = b;
647 *usec = u;
648
649 kfree(ratestr);
650 return;
651
652 fail:
653 pr_warn("Failed to parse network rate limit. Traffic unlimited.\n");
654 kfree(ratestr);
655}
656
657static int xen_net_read_mac(struct xenbus_device *dev, u8 mac[])
658{
659 char *s, *e, *macstr;
660 int i;
661
662 macstr = s = xenbus_read(XBT_NIL, dev->nodename, "mac", NULL);
663 if (IS_ERR(macstr))
664 return PTR_ERR(macstr);
665
666 for (i = 0; i < ETH_ALEN; i++) {
667 mac[i] = simple_strtoul(s, &e, 16);
668 if ((s == e) || (*e != ((i == ETH_ALEN-1) ? '\0' : ':'))) {
669 kfree(macstr);
670 return -ENOENT;
671 }
672 s = e+1;
673 }
674
675 kfree(macstr);
676 return 0;
677}
678
679static void xen_net_rate_changed(struct xenbus_watch *watch,
680 const char *path, const char *token)
681{
682 struct xenvif *vif = container_of(watch, struct xenvif, credit_watch);
683 struct xenbus_device *dev = xenvif_to_xenbus_device(vif);
684 unsigned long credit_bytes;
685 unsigned long credit_usec;
686 unsigned int queue_index;
687
688 xen_net_read_rate(dev, &credit_bytes, &credit_usec);
689 for (queue_index = 0; queue_index < vif->num_queues; queue_index++) {
690 struct xenvif_queue *queue = &vif->queues[queue_index];
691
692 queue->credit_bytes = credit_bytes;
693 queue->credit_usec = credit_usec;
694 if (!mod_timer_pending(&queue->credit_timeout, jiffies) &&
695 queue->remaining_credit > queue->credit_bytes) {
696 queue->remaining_credit = queue->credit_bytes;
697 }
698 }
699}
700
701static int xen_register_credit_watch(struct xenbus_device *dev,
702 struct xenvif *vif)
703{
704 int err = 0;
705 char *node;
706 unsigned maxlen = strlen(dev->nodename) + sizeof("/rate");
707
708 if (vif->credit_watch.node)
709 return -EADDRINUSE;
710
711 node = kmalloc(maxlen, GFP_KERNEL);
712 if (!node)
713 return -ENOMEM;
714 snprintf(node, maxlen, "%s/rate", dev->nodename);
715 vif->credit_watch.node = node;
716 vif->credit_watch.callback = xen_net_rate_changed;
717 err = register_xenbus_watch(&vif->credit_watch);
718 if (err) {
719 pr_err("Failed to set watcher %s\n", vif->credit_watch.node);
720 kfree(node);
721 vif->credit_watch.node = NULL;
722 vif->credit_watch.callback = NULL;
723 }
724 return err;
725}
726
727static void xen_unregister_credit_watch(struct xenvif *vif)
728{
729 if (vif->credit_watch.node) {
730 unregister_xenbus_watch(&vif->credit_watch);
731 kfree(vif->credit_watch.node);
732 vif->credit_watch.node = NULL;
733 }
734}
735
736static void xen_mcast_ctrl_changed(struct xenbus_watch *watch,
737 const char *path, const char *token)
738{
739 struct xenvif *vif = container_of(watch, struct xenvif,
740 mcast_ctrl_watch);
741 struct xenbus_device *dev = xenvif_to_xenbus_device(vif);
742
743 vif->multicast_control = !!xenbus_read_unsigned(dev->otherend,
744 "request-multicast-control", 0);
745}
746
747static int xen_register_mcast_ctrl_watch(struct xenbus_device *dev,
748 struct xenvif *vif)
749{
750 int err = 0;
751 char *node;
752 unsigned maxlen = strlen(dev->otherend) +
753 sizeof("/request-multicast-control");
754
755 if (vif->mcast_ctrl_watch.node) {
756 pr_err_ratelimited("Watch is already registered\n");
757 return -EADDRINUSE;
758 }
759
760 node = kmalloc(maxlen, GFP_KERNEL);
761 if (!node) {
762 pr_err("Failed to allocate memory for watch\n");
763 return -ENOMEM;
764 }
765 snprintf(node, maxlen, "%s/request-multicast-control",
766 dev->otherend);
767 vif->mcast_ctrl_watch.node = node;
768 vif->mcast_ctrl_watch.callback = xen_mcast_ctrl_changed;
769 err = register_xenbus_watch(&vif->mcast_ctrl_watch);
770 if (err) {
771 pr_err("Failed to set watcher %s\n",
772 vif->mcast_ctrl_watch.node);
773 kfree(node);
774 vif->mcast_ctrl_watch.node = NULL;
775 vif->mcast_ctrl_watch.callback = NULL;
776 }
777 return err;
778}
779
780static void xen_unregister_mcast_ctrl_watch(struct xenvif *vif)
781{
782 if (vif->mcast_ctrl_watch.node) {
783 unregister_xenbus_watch(&vif->mcast_ctrl_watch);
784 kfree(vif->mcast_ctrl_watch.node);
785 vif->mcast_ctrl_watch.node = NULL;
786 }
787}
788
789static void xen_register_watchers(struct xenbus_device *dev,
790 struct xenvif *vif)
791{
792 xen_register_credit_watch(dev, vif);
793 xen_register_mcast_ctrl_watch(dev, vif);
794}
795
796static void xen_unregister_watchers(struct xenvif *vif)
797{
798 xen_unregister_mcast_ctrl_watch(vif);
799 xen_unregister_credit_watch(vif);
800}
801
802static void unregister_hotplug_status_watch(struct backend_info *be)
803{
804 if (be->have_hotplug_status_watch) {
805 unregister_xenbus_watch(&be->hotplug_status_watch);
806 kfree(be->hotplug_status_watch.node);
807 }
808 be->have_hotplug_status_watch = 0;
809}
810
811static void hotplug_status_changed(struct xenbus_watch *watch,
812 const char *path,
813 const char *token)
814{
815 struct backend_info *be = container_of(watch,
816 struct backend_info,
817 hotplug_status_watch);
818 char *str;
819 unsigned int len;
820
821 str = xenbus_read(XBT_NIL, be->dev->nodename, "hotplug-status", &len);
822 if (IS_ERR(str))
823 return;
824 if (len == sizeof("connected")-1 && !memcmp(str, "connected", len)) {
825 /* Complete any pending state change */
826 xenbus_switch_state(be->dev, be->state);
827
828 /* Not interested in this watch anymore. */
829 unregister_hotplug_status_watch(be);
830 }
831 kfree(str);
832}
833
834static int connect_ctrl_ring(struct backend_info *be)
835{
836 struct xenbus_device *dev = be->dev;
837 struct xenvif *vif = be->vif;
838 unsigned int val;
839 grant_ref_t ring_ref;
840 unsigned int evtchn;
841 int err;
842
843 err = xenbus_scanf(XBT_NIL, dev->otherend,
844 "ctrl-ring-ref", "%u", &val);
845 if (err < 0)
846 goto done; /* The frontend does not have a control ring */
847
848 ring_ref = val;
849
850 err = xenbus_scanf(XBT_NIL, dev->otherend,
851 "event-channel-ctrl", "%u", &val);
852 if (err < 0) {
853 xenbus_dev_fatal(dev, err,
854 "reading %s/event-channel-ctrl",
855 dev->otherend);
856 goto fail;
857 }
858
859 evtchn = val;
860
861 err = xenvif_connect_ctrl(vif, ring_ref, evtchn);
862 if (err) {
863 xenbus_dev_fatal(dev, err,
864 "mapping shared-frame %u port %u",
865 ring_ref, evtchn);
866 goto fail;
867 }
868
869done:
870 return 0;
871
872fail:
873 return err;
874}
875
876static void connect(struct backend_info *be)
877{
878 int err;
879 struct xenbus_device *dev = be->dev;
880 unsigned long credit_bytes, credit_usec;
881 unsigned int queue_index;
882 unsigned int requested_num_queues;
883 struct xenvif_queue *queue;
884
885 /* Check whether the frontend requested multiple queues
886 * and read the number requested.
887 */
888 requested_num_queues = xenbus_read_unsigned(dev->otherend,
889 "multi-queue-num-queues", 1);
890 if (requested_num_queues > xenvif_max_queues) {
891 /* buggy or malicious guest */
892 xenbus_dev_fatal(dev, -EINVAL,
893 "guest requested %u queues, exceeding the maximum of %u.",
894 requested_num_queues, xenvif_max_queues);
895 return;
896 }
897
898 err = xen_net_read_mac(dev, be->vif->fe_dev_addr);
899 if (err) {
900 xenbus_dev_fatal(dev, err, "parsing %s/mac", dev->nodename);
901 return;
902 }
903
904 xen_net_read_rate(dev, &credit_bytes, &credit_usec);
905 xen_unregister_watchers(be->vif);
906 xen_register_watchers(dev, be->vif);
907 read_xenbus_vif_flags(be);
908
909 err = connect_ctrl_ring(be);
910 if (err) {
911 xenbus_dev_fatal(dev, err, "connecting control ring");
912 return;
913 }
914
915 /* Use the number of queues requested by the frontend */
916 be->vif->queues = vzalloc(array_size(requested_num_queues,
917 sizeof(struct xenvif_queue)));
918 if (!be->vif->queues) {
919 xenbus_dev_fatal(dev, -ENOMEM,
920 "allocating queues");
921 return;
922 }
923
924 be->vif->num_queues = requested_num_queues;
925 be->vif->stalled_queues = requested_num_queues;
926
927 for (queue_index = 0; queue_index < requested_num_queues; ++queue_index) {
928 queue = &be->vif->queues[queue_index];
929 queue->vif = be->vif;
930 queue->id = queue_index;
931 snprintf(queue->name, sizeof(queue->name), "%s-q%u",
932 be->vif->dev->name, queue->id);
933
934 err = xenvif_init_queue(queue);
935 if (err) {
936 /* xenvif_init_queue() cleans up after itself on
937 * failure, but we need to clean up any previously
938 * initialised queues. Set num_queues to i so that
939 * earlier queues can be destroyed using the regular
940 * disconnect logic.
941 */
942 be->vif->num_queues = queue_index;
943 goto err;
944 }
945
946 queue->credit_bytes = credit_bytes;
947 queue->remaining_credit = credit_bytes;
948 queue->credit_usec = credit_usec;
949
950 err = connect_data_rings(be, queue);
951 if (err) {
952 /* connect_data_rings() cleans up after itself on
953 * failure, but we need to clean up after
954 * xenvif_init_queue() here, and also clean up any
955 * previously initialised queues.
956 */
957 xenvif_deinit_queue(queue);
958 be->vif->num_queues = queue_index;
959 goto err;
960 }
961 }
962
963#ifdef CONFIG_DEBUG_FS
964 xenvif_debugfs_addif(be->vif);
965#endif /* CONFIG_DEBUG_FS */
966
967 /* Initialisation completed, tell core driver the number of
968 * active queues.
969 */
970 rtnl_lock();
971 netif_set_real_num_tx_queues(be->vif->dev, requested_num_queues);
972 netif_set_real_num_rx_queues(be->vif->dev, requested_num_queues);
973 rtnl_unlock();
974
975 xenvif_carrier_on(be->vif);
976
977 unregister_hotplug_status_watch(be);
978 err = xenbus_watch_pathfmt(dev, &be->hotplug_status_watch,
979 hotplug_status_changed,
980 "%s/%s", dev->nodename, "hotplug-status");
981 if (!err)
982 be->have_hotplug_status_watch = 1;
983
984 netif_tx_wake_all_queues(be->vif->dev);
985
986 return;
987
988err:
989 if (be->vif->num_queues > 0)
990 xenvif_disconnect_data(be->vif); /* Clean up existing queues */
991 for (queue_index = 0; queue_index < be->vif->num_queues; ++queue_index)
992 xenvif_deinit_queue(&be->vif->queues[queue_index]);
993 vfree(be->vif->queues);
994 be->vif->queues = NULL;
995 be->vif->num_queues = 0;
996 xenvif_disconnect_ctrl(be->vif);
997 return;
998}
999
1000
1001static int connect_data_rings(struct backend_info *be,
1002 struct xenvif_queue *queue)
1003{
1004 struct xenbus_device *dev = be->dev;
1005 unsigned int num_queues = queue->vif->num_queues;
1006 unsigned long tx_ring_ref, rx_ring_ref;
1007 unsigned int tx_evtchn, rx_evtchn;
1008 int err;
1009 char *xspath;
1010 size_t xspathsize;
1011 const size_t xenstore_path_ext_size = 11; /* sufficient for "/queue-NNN" */
1012
1013 /* If the frontend requested 1 queue, or we have fallen back
1014 * to single queue due to lack of frontend support for multi-
1015 * queue, expect the remaining XenStore keys in the toplevel
1016 * directory. Otherwise, expect them in a subdirectory called
1017 * queue-N.
1018 */
1019 if (num_queues == 1) {
1020 xspath = kzalloc(strlen(dev->otherend) + 1, GFP_KERNEL);
1021 if (!xspath) {
1022 xenbus_dev_fatal(dev, -ENOMEM,
1023 "reading ring references");
1024 return -ENOMEM;
1025 }
1026 strcpy(xspath, dev->otherend);
1027 } else {
1028 xspathsize = strlen(dev->otherend) + xenstore_path_ext_size;
1029 xspath = kzalloc(xspathsize, GFP_KERNEL);
1030 if (!xspath) {
1031 xenbus_dev_fatal(dev, -ENOMEM,
1032 "reading ring references");
1033 return -ENOMEM;
1034 }
1035 snprintf(xspath, xspathsize, "%s/queue-%u", dev->otherend,
1036 queue->id);
1037 }
1038
1039 err = xenbus_gather(XBT_NIL, xspath,
1040 "tx-ring-ref", "%lu", &tx_ring_ref,
1041 "rx-ring-ref", "%lu", &rx_ring_ref, NULL);
1042 if (err) {
1043 xenbus_dev_fatal(dev, err,
1044 "reading %s/ring-ref",
1045 xspath);
1046 goto err;
1047 }
1048
1049 /* Try split event channels first, then single event channel. */
1050 err = xenbus_gather(XBT_NIL, xspath,
1051 "event-channel-tx", "%u", &tx_evtchn,
1052 "event-channel-rx", "%u", &rx_evtchn, NULL);
1053 if (err < 0) {
1054 err = xenbus_scanf(XBT_NIL, xspath,
1055 "event-channel", "%u", &tx_evtchn);
1056 if (err < 0) {
1057 xenbus_dev_fatal(dev, err,
1058 "reading %s/event-channel(-tx/rx)",
1059 xspath);
1060 goto err;
1061 }
1062 rx_evtchn = tx_evtchn;
1063 }
1064
1065 /* Map the shared frame, irq etc. */
1066 err = xenvif_connect_data(queue, tx_ring_ref, rx_ring_ref,
1067 tx_evtchn, rx_evtchn);
1068 if (err) {
1069 xenbus_dev_fatal(dev, err,
1070 "mapping shared-frames %lu/%lu port tx %u rx %u",
1071 tx_ring_ref, rx_ring_ref,
1072 tx_evtchn, rx_evtchn);
1073 goto err;
1074 }
1075
1076 err = 0;
1077err: /* Regular return falls through with err == 0 */
1078 kfree(xspath);
1079 return err;
1080}
1081
1082static int read_xenbus_vif_flags(struct backend_info *be)
1083{
1084 struct xenvif *vif = be->vif;
1085 struct xenbus_device *dev = be->dev;
1086 unsigned int rx_copy;
1087 int err;
1088
1089 err = xenbus_scanf(XBT_NIL, dev->otherend, "request-rx-copy", "%u",
1090 &rx_copy);
1091 if (err == -ENOENT) {
1092 err = 0;
1093 rx_copy = 0;
1094 }
1095 if (err < 0) {
1096 xenbus_dev_fatal(dev, err, "reading %s/request-rx-copy",
1097 dev->otherend);
1098 return err;
1099 }
1100 if (!rx_copy)
1101 return -EOPNOTSUPP;
1102
1103 if (!xenbus_read_unsigned(dev->otherend, "feature-rx-notify", 0)) {
1104 /* - Reduce drain timeout to poll more frequently for
1105 * Rx requests.
1106 * - Disable Rx stall detection.
1107 */
1108 be->vif->drain_timeout = msecs_to_jiffies(30);
1109 be->vif->stall_timeout = 0;
1110 }
1111
1112 vif->can_sg = !!xenbus_read_unsigned(dev->otherend, "feature-sg", 0);
1113
1114 vif->gso_mask = 0;
1115
1116 if (xenbus_read_unsigned(dev->otherend, "feature-gso-tcpv4", 0))
1117 vif->gso_mask |= GSO_BIT(TCPV4);
1118
1119 if (xenbus_read_unsigned(dev->otherend, "feature-gso-tcpv6", 0))
1120 vif->gso_mask |= GSO_BIT(TCPV6);
1121
1122 vif->ip_csum = !xenbus_read_unsigned(dev->otherend,
1123 "feature-no-csum-offload", 0);
1124
1125 vif->ipv6_csum = !!xenbus_read_unsigned(dev->otherend,
1126 "feature-ipv6-csum-offload", 0);
1127
1128 return 0;
1129}
1130
1131static const struct xenbus_device_id netback_ids[] = {
1132 { "vif" },
1133 { "" }
1134};
1135
1136static struct xenbus_driver netback_driver = {
1137 .ids = netback_ids,
1138 .probe = netback_probe,
1139 .remove = netback_remove,
1140 .uevent = netback_uevent,
1141 .otherend_changed = frontend_changed,
1142};
1143
1144int xenvif_xenbus_init(void)
1145{
1146 return xenbus_register_backend(&netback_driver);
1147}
1148
1149void xenvif_xenbus_fini(void)
1150{
1151 return xenbus_unregister_driver(&netback_driver);
1152}