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