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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
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
197
198
199
200
201
202
203static int netback_uevent(struct xenbus_device *xdev,
204 struct kobj_uevent_env *env)
205{
206 struct backend_info *be = dev_get_drvdata(&xdev->dev);
207
208 if (!be)
209 return 0;
210
211 if (add_uevent_var(env, "script=%s", be->hotplug_script))
212 return -ENOMEM;
213
214 if (!be->vif)
215 return 0;
216
217 return add_uevent_var(env, "vif=%s", be->vif->dev->name);
218}
219
220
221static int backend_create_xenvif(struct backend_info *be)
222{
223 int err;
224 long handle;
225 struct xenbus_device *dev = be->dev;
226 struct xenvif *vif;
227
228 if (be->vif != NULL)
229 return 0;
230
231 err = xenbus_scanf(XBT_NIL, dev->nodename, "handle", "%li", &handle);
232 if (err != 1) {
233 xenbus_dev_fatal(dev, err, "reading handle");
234 return (err < 0) ? err : -EINVAL;
235 }
236
237 vif = xenvif_alloc(&dev->dev, dev->otherend_id, handle);
238 if (IS_ERR(vif)) {
239 err = PTR_ERR(vif);
240 xenbus_dev_fatal(dev, err, "creating interface");
241 return err;
242 }
243 be->vif = vif;
244 vif->be = be;
245
246 kobject_uevent(&dev->dev.kobj, KOBJ_ONLINE);
247 return 0;
248}
249
250static void backend_disconnect(struct backend_info *be)
251{
252 struct xenvif *vif = be->vif;
253
254 if (vif) {
255 unsigned int num_queues = vif->num_queues;
256 unsigned int queue_index;
257
258 xen_unregister_watchers(vif);
259#ifdef CONFIG_DEBUG_FS
260 xenvif_debugfs_delif(vif);
261#endif
262 xenvif_disconnect_data(vif);
263
264
265
266
267 vif->num_queues = 0;
268 synchronize_net();
269
270 for (queue_index = 0; queue_index < num_queues; ++queue_index)
271 xenvif_deinit_queue(&vif->queues[queue_index]);
272
273 vfree(vif->queues);
274 vif->queues = NULL;
275
276 xenvif_disconnect_ctrl(vif);
277 }
278}
279
280static void backend_connect(struct backend_info *be)
281{
282 if (be->vif)
283 connect(be);
284}
285
286static inline void backend_switch_state(struct backend_info *be,
287 enum xenbus_state state)
288{
289 struct xenbus_device *dev = be->dev;
290
291 pr_debug("%s -> %s\n", dev->nodename, xenbus_strstate(state));
292 be->state = state;
293
294
295
296
297 if (!be->have_hotplug_status_watch)
298 xenbus_switch_state(dev, state);
299}
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320
321static void set_backend_state(struct backend_info *be,
322 enum xenbus_state state)
323{
324 while (be->state != state) {
325 switch (be->state) {
326 case XenbusStateInitialising:
327 switch (state) {
328 case XenbusStateInitWait:
329 case XenbusStateConnected:
330 case XenbusStateClosing:
331 backend_switch_state(be, XenbusStateInitWait);
332 break;
333 case XenbusStateClosed:
334 backend_switch_state(be, XenbusStateClosed);
335 break;
336 default:
337 BUG();
338 }
339 break;
340 case XenbusStateClosed:
341 switch (state) {
342 case XenbusStateInitWait:
343 case XenbusStateConnected:
344 backend_switch_state(be, XenbusStateInitWait);
345 break;
346 case XenbusStateClosing:
347 backend_switch_state(be, XenbusStateClosing);
348 break;
349 default:
350 BUG();
351 }
352 break;
353 case XenbusStateInitWait:
354 switch (state) {
355 case XenbusStateConnected:
356 backend_connect(be);
357 backend_switch_state(be, XenbusStateConnected);
358 break;
359 case XenbusStateClosing:
360 case XenbusStateClosed:
361 backend_switch_state(be, XenbusStateClosing);
362 break;
363 default:
364 BUG();
365 }
366 break;
367 case XenbusStateConnected:
368 switch (state) {
369 case XenbusStateInitWait:
370 case XenbusStateClosing:
371 case XenbusStateClosed:
372 backend_disconnect(be);
373 backend_switch_state(be, XenbusStateClosing);
374 break;
375 default:
376 BUG();
377 }
378 break;
379 case XenbusStateClosing:
380 switch (state) {
381 case XenbusStateInitWait:
382 case XenbusStateConnected:
383 case XenbusStateClosed:
384 backend_switch_state(be, XenbusStateClosed);
385 break;
386 default:
387 BUG();
388 }
389 break;
390 default:
391 BUG();
392 }
393 }
394}
395
396static void read_xenbus_frontend_xdp(struct backend_info *be,
397 struct xenbus_device *dev)
398{
399 struct xenvif *vif = be->vif;
400 u16 headroom;
401 int err;
402
403 err = xenbus_scanf(XBT_NIL, dev->otherend,
404 "xdp-headroom", "%hu", &headroom);
405 if (err != 1) {
406 vif->xdp_headroom = 0;
407 return;
408 }
409 if (headroom > XEN_NETIF_MAX_XDP_HEADROOM)
410 headroom = XEN_NETIF_MAX_XDP_HEADROOM;
411 vif->xdp_headroom = headroom;
412}
413
414
415
416
417static void frontend_changed(struct xenbus_device *dev,
418 enum xenbus_state frontend_state)
419{
420 struct backend_info *be = dev_get_drvdata(&dev->dev);
421
422 pr_debug("%s -> %s\n", dev->otherend, xenbus_strstate(frontend_state));
423
424 be->frontend_state = frontend_state;
425
426 switch (frontend_state) {
427 case XenbusStateInitialising:
428 set_backend_state(be, XenbusStateInitWait);
429 break;
430
431 case XenbusStateInitialised:
432 break;
433
434 case XenbusStateConnected:
435 set_backend_state(be, XenbusStateConnected);
436 break;
437
438 case XenbusStateReconfiguring:
439 read_xenbus_frontend_xdp(be, dev);
440 xenbus_switch_state(dev, XenbusStateReconfigured);
441 break;
442
443 case XenbusStateClosing:
444 set_backend_state(be, XenbusStateClosing);
445 break;
446
447 case XenbusStateClosed:
448 set_backend_state(be, XenbusStateClosed);
449 if (xenbus_dev_is_online(dev))
450 break;
451 fallthrough;
452 case XenbusStateUnknown:
453 set_backend_state(be, XenbusStateClosed);
454 device_unregister(&dev->dev);
455 break;
456
457 default:
458 xenbus_dev_fatal(dev, -EINVAL, "saw state %d at frontend",
459 frontend_state);
460 break;
461 }
462}
463
464
465static void xen_net_read_rate(struct xenbus_device *dev,
466 unsigned long *bytes, unsigned long *usec)
467{
468 char *s, *e;
469 unsigned long b, u;
470 char *ratestr;
471
472
473 *bytes = ~0UL;
474 *usec = 0;
475
476 ratestr = xenbus_read(XBT_NIL, dev->nodename, "rate", NULL);
477 if (IS_ERR(ratestr))
478 return;
479
480 s = ratestr;
481 b = simple_strtoul(s, &e, 10);
482 if ((s == e) || (*e != ','))
483 goto fail;
484
485 s = e + 1;
486 u = simple_strtoul(s, &e, 10);
487 if ((s == e) || (*e != '\0'))
488 goto fail;
489
490 *bytes = b;
491 *usec = u;
492
493 kfree(ratestr);
494 return;
495
496 fail:
497 pr_warn("Failed to parse network rate limit. Traffic unlimited.\n");
498 kfree(ratestr);
499}
500
501static int xen_net_read_mac(struct xenbus_device *dev, u8 mac[])
502{
503 char *s, *e, *macstr;
504 int i;
505
506 macstr = s = xenbus_read(XBT_NIL, dev->nodename, "mac", NULL);
507 if (IS_ERR(macstr))
508 return PTR_ERR(macstr);
509
510 for (i = 0; i < ETH_ALEN; i++) {
511 mac[i] = simple_strtoul(s, &e, 16);
512 if ((s == e) || (*e != ((i == ETH_ALEN-1) ? '\0' : ':'))) {
513 kfree(macstr);
514 return -ENOENT;
515 }
516 s = e+1;
517 }
518
519 kfree(macstr);
520 return 0;
521}
522
523static void xen_net_rate_changed(struct xenbus_watch *watch,
524 const char *path, const char *token)
525{
526 struct xenvif *vif = container_of(watch, struct xenvif, credit_watch);
527 struct xenbus_device *dev = xenvif_to_xenbus_device(vif);
528 unsigned long credit_bytes;
529 unsigned long credit_usec;
530 unsigned int queue_index;
531
532 xen_net_read_rate(dev, &credit_bytes, &credit_usec);
533 for (queue_index = 0; queue_index < vif->num_queues; queue_index++) {
534 struct xenvif_queue *queue = &vif->queues[queue_index];
535
536 queue->credit_bytes = credit_bytes;
537 queue->credit_usec = credit_usec;
538 if (!mod_timer_pending(&queue->credit_timeout, jiffies) &&
539 queue->remaining_credit > queue->credit_bytes) {
540 queue->remaining_credit = queue->credit_bytes;
541 }
542 }
543}
544
545static int xen_register_credit_watch(struct xenbus_device *dev,
546 struct xenvif *vif)
547{
548 int err = 0;
549 char *node;
550 unsigned maxlen = strlen(dev->nodename) + sizeof("/rate");
551
552 if (vif->credit_watch.node)
553 return -EADDRINUSE;
554
555 node = kmalloc(maxlen, GFP_KERNEL);
556 if (!node)
557 return -ENOMEM;
558 snprintf(node, maxlen, "%s/rate", dev->nodename);
559 vif->credit_watch.node = node;
560 vif->credit_watch.callback = xen_net_rate_changed;
561 err = register_xenbus_watch(&vif->credit_watch);
562 if (err) {
563 pr_err("Failed to set watcher %s\n", vif->credit_watch.node);
564 kfree(node);
565 vif->credit_watch.node = NULL;
566 vif->credit_watch.callback = NULL;
567 }
568 return err;
569}
570
571static void xen_unregister_credit_watch(struct xenvif *vif)
572{
573 if (vif->credit_watch.node) {
574 unregister_xenbus_watch(&vif->credit_watch);
575 kfree(vif->credit_watch.node);
576 vif->credit_watch.node = NULL;
577 }
578}
579
580static void xen_mcast_ctrl_changed(struct xenbus_watch *watch,
581 const char *path, const char *token)
582{
583 struct xenvif *vif = container_of(watch, struct xenvif,
584 mcast_ctrl_watch);
585 struct xenbus_device *dev = xenvif_to_xenbus_device(vif);
586
587 vif->multicast_control = !!xenbus_read_unsigned(dev->otherend,
588 "request-multicast-control", 0);
589}
590
591static int xen_register_mcast_ctrl_watch(struct xenbus_device *dev,
592 struct xenvif *vif)
593{
594 int err = 0;
595 char *node;
596 unsigned maxlen = strlen(dev->otherend) +
597 sizeof("/request-multicast-control");
598
599 if (vif->mcast_ctrl_watch.node) {
600 pr_err_ratelimited("Watch is already registered\n");
601 return -EADDRINUSE;
602 }
603
604 node = kmalloc(maxlen, GFP_KERNEL);
605 if (!node) {
606 pr_err("Failed to allocate memory for watch\n");
607 return -ENOMEM;
608 }
609 snprintf(node, maxlen, "%s/request-multicast-control",
610 dev->otherend);
611 vif->mcast_ctrl_watch.node = node;
612 vif->mcast_ctrl_watch.callback = xen_mcast_ctrl_changed;
613 err = register_xenbus_watch(&vif->mcast_ctrl_watch);
614 if (err) {
615 pr_err("Failed to set watcher %s\n",
616 vif->mcast_ctrl_watch.node);
617 kfree(node);
618 vif->mcast_ctrl_watch.node = NULL;
619 vif->mcast_ctrl_watch.callback = NULL;
620 }
621 return err;
622}
623
624static void xen_unregister_mcast_ctrl_watch(struct xenvif *vif)
625{
626 if (vif->mcast_ctrl_watch.node) {
627 unregister_xenbus_watch(&vif->mcast_ctrl_watch);
628 kfree(vif->mcast_ctrl_watch.node);
629 vif->mcast_ctrl_watch.node = NULL;
630 }
631}
632
633static void xen_register_watchers(struct xenbus_device *dev,
634 struct xenvif *vif)
635{
636 xen_register_credit_watch(dev, vif);
637 xen_register_mcast_ctrl_watch(dev, vif);
638}
639
640static void xen_unregister_watchers(struct xenvif *vif)
641{
642 xen_unregister_mcast_ctrl_watch(vif);
643 xen_unregister_credit_watch(vif);
644}
645
646static void unregister_hotplug_status_watch(struct backend_info *be)
647{
648 if (be->have_hotplug_status_watch) {
649 unregister_xenbus_watch(&be->hotplug_status_watch);
650 kfree(be->hotplug_status_watch.node);
651 }
652 be->have_hotplug_status_watch = 0;
653}
654
655static void hotplug_status_changed(struct xenbus_watch *watch,
656 const char *path,
657 const char *token)
658{
659 struct backend_info *be = container_of(watch,
660 struct backend_info,
661 hotplug_status_watch);
662 char *str;
663 unsigned int len;
664
665 str = xenbus_read(XBT_NIL, be->dev->nodename, "hotplug-status", &len);
666 if (IS_ERR(str))
667 return;
668 if (len == sizeof("connected")-1 && !memcmp(str, "connected", len)) {
669
670 xenbus_switch_state(be->dev, be->state);
671
672
673 unregister_hotplug_status_watch(be);
674 xenbus_rm(XBT_NIL, be->dev->nodename, "hotplug-status");
675 }
676 kfree(str);
677}
678
679static int connect_ctrl_ring(struct backend_info *be)
680{
681 struct xenbus_device *dev = be->dev;
682 struct xenvif *vif = be->vif;
683 unsigned int val;
684 grant_ref_t ring_ref;
685 unsigned int evtchn;
686 int err;
687
688 err = xenbus_scanf(XBT_NIL, dev->otherend,
689 "ctrl-ring-ref", "%u", &val);
690 if (err < 0)
691 goto done;
692
693 ring_ref = val;
694
695 err = xenbus_scanf(XBT_NIL, dev->otherend,
696 "event-channel-ctrl", "%u", &val);
697 if (err < 0) {
698 xenbus_dev_fatal(dev, err,
699 "reading %s/event-channel-ctrl",
700 dev->otherend);
701 goto fail;
702 }
703
704 evtchn = val;
705
706 err = xenvif_connect_ctrl(vif, ring_ref, evtchn);
707 if (err) {
708 xenbus_dev_fatal(dev, err,
709 "mapping shared-frame %u port %u",
710 ring_ref, evtchn);
711 goto fail;
712 }
713
714done:
715 return 0;
716
717fail:
718 return err;
719}
720
721static void connect(struct backend_info *be)
722{
723 int err;
724 struct xenbus_device *dev = be->dev;
725 unsigned long credit_bytes, credit_usec;
726 unsigned int queue_index;
727 unsigned int requested_num_queues;
728 struct xenvif_queue *queue;
729
730
731
732
733 requested_num_queues = xenbus_read_unsigned(dev->otherend,
734 "multi-queue-num-queues", 1);
735 if (requested_num_queues > xenvif_max_queues) {
736
737 xenbus_dev_fatal(dev, -EINVAL,
738 "guest requested %u queues, exceeding the maximum of %u.",
739 requested_num_queues, xenvif_max_queues);
740 return;
741 }
742
743 err = xen_net_read_mac(dev, be->vif->fe_dev_addr);
744 if (err) {
745 xenbus_dev_fatal(dev, err, "parsing %s/mac", dev->nodename);
746 return;
747 }
748
749 xen_net_read_rate(dev, &credit_bytes, &credit_usec);
750 xen_unregister_watchers(be->vif);
751 xen_register_watchers(dev, be->vif);
752 read_xenbus_vif_flags(be);
753
754 err = connect_ctrl_ring(be);
755 if (err) {
756 xenbus_dev_fatal(dev, err, "connecting control ring");
757 return;
758 }
759
760
761 be->vif->queues = vzalloc(array_size(requested_num_queues,
762 sizeof(struct xenvif_queue)));
763 if (!be->vif->queues) {
764 xenbus_dev_fatal(dev, -ENOMEM,
765 "allocating queues");
766 return;
767 }
768
769 be->vif->num_queues = requested_num_queues;
770 be->vif->stalled_queues = requested_num_queues;
771
772 for (queue_index = 0; queue_index < requested_num_queues; ++queue_index) {
773 queue = &be->vif->queues[queue_index];
774 queue->vif = be->vif;
775 queue->id = queue_index;
776 snprintf(queue->name, sizeof(queue->name), "%s-q%u",
777 be->vif->dev->name, queue->id);
778
779 err = xenvif_init_queue(queue);
780 if (err) {
781
782
783
784
785
786
787 be->vif->num_queues = queue_index;
788 goto err;
789 }
790
791 queue->credit_bytes = credit_bytes;
792 queue->remaining_credit = credit_bytes;
793 queue->credit_usec = credit_usec;
794
795 err = connect_data_rings(be, queue);
796 if (err) {
797
798
799
800
801
802 xenvif_deinit_queue(queue);
803 be->vif->num_queues = queue_index;
804 goto err;
805 }
806 }
807
808#ifdef CONFIG_DEBUG_FS
809 xenvif_debugfs_addif(be->vif);
810#endif
811
812
813
814
815 rtnl_lock();
816 netif_set_real_num_tx_queues(be->vif->dev, requested_num_queues);
817 netif_set_real_num_rx_queues(be->vif->dev, requested_num_queues);
818 rtnl_unlock();
819
820 xenvif_carrier_on(be->vif);
821
822 unregister_hotplug_status_watch(be);
823 err = xenbus_watch_pathfmt(dev, &be->hotplug_status_watch,
824 hotplug_status_changed,
825 "%s/%s", dev->nodename, "hotplug-status");
826 if (!err)
827 be->have_hotplug_status_watch = 1;
828
829 netif_tx_wake_all_queues(be->vif->dev);
830
831 return;
832
833err:
834 if (be->vif->num_queues > 0)
835 xenvif_disconnect_data(be->vif);
836 for (queue_index = 0; queue_index < be->vif->num_queues; ++queue_index)
837 xenvif_deinit_queue(&be->vif->queues[queue_index]);
838 vfree(be->vif->queues);
839 be->vif->queues = NULL;
840 be->vif->num_queues = 0;
841 xenvif_disconnect_ctrl(be->vif);
842 return;
843}
844
845
846static int connect_data_rings(struct backend_info *be,
847 struct xenvif_queue *queue)
848{
849 struct xenbus_device *dev = be->dev;
850 unsigned int num_queues = queue->vif->num_queues;
851 unsigned long tx_ring_ref, rx_ring_ref;
852 unsigned int tx_evtchn, rx_evtchn;
853 int err;
854 char *xspath;
855 size_t xspathsize;
856 const size_t xenstore_path_ext_size = 11;
857
858
859
860
861
862
863
864 if (num_queues == 1) {
865 xspath = kzalloc(strlen(dev->otherend) + 1, GFP_KERNEL);
866 if (!xspath) {
867 xenbus_dev_fatal(dev, -ENOMEM,
868 "reading ring references");
869 return -ENOMEM;
870 }
871 strcpy(xspath, dev->otherend);
872 } else {
873 xspathsize = strlen(dev->otherend) + xenstore_path_ext_size;
874 xspath = kzalloc(xspathsize, GFP_KERNEL);
875 if (!xspath) {
876 xenbus_dev_fatal(dev, -ENOMEM,
877 "reading ring references");
878 return -ENOMEM;
879 }
880 snprintf(xspath, xspathsize, "%s/queue-%u", dev->otherend,
881 queue->id);
882 }
883
884 err = xenbus_gather(XBT_NIL, xspath,
885 "tx-ring-ref", "%lu", &tx_ring_ref,
886 "rx-ring-ref", "%lu", &rx_ring_ref, NULL);
887 if (err) {
888 xenbus_dev_fatal(dev, err,
889 "reading %s/ring-ref",
890 xspath);
891 goto err;
892 }
893
894
895 err = xenbus_gather(XBT_NIL, xspath,
896 "event-channel-tx", "%u", &tx_evtchn,
897 "event-channel-rx", "%u", &rx_evtchn, NULL);
898 if (err < 0) {
899 err = xenbus_scanf(XBT_NIL, xspath,
900 "event-channel", "%u", &tx_evtchn);
901 if (err < 0) {
902 xenbus_dev_fatal(dev, err,
903 "reading %s/event-channel(-tx/rx)",
904 xspath);
905 goto err;
906 }
907 rx_evtchn = tx_evtchn;
908 }
909
910
911 err = xenvif_connect_data(queue, tx_ring_ref, rx_ring_ref,
912 tx_evtchn, rx_evtchn);
913 if (err) {
914 xenbus_dev_fatal(dev, err,
915 "mapping shared-frames %lu/%lu port tx %u rx %u",
916 tx_ring_ref, rx_ring_ref,
917 tx_evtchn, rx_evtchn);
918 goto err;
919 }
920
921 err = 0;
922err:
923 kfree(xspath);
924 return err;
925}
926
927static int read_xenbus_vif_flags(struct backend_info *be)
928{
929 struct xenvif *vif = be->vif;
930 struct xenbus_device *dev = be->dev;
931 unsigned int rx_copy;
932 int err;
933
934 err = xenbus_scanf(XBT_NIL, dev->otherend, "request-rx-copy", "%u",
935 &rx_copy);
936 if (err == -ENOENT) {
937 err = 0;
938 rx_copy = 0;
939 }
940 if (err < 0) {
941 xenbus_dev_fatal(dev, err, "reading %s/request-rx-copy",
942 dev->otherend);
943 return err;
944 }
945 if (!rx_copy)
946 return -EOPNOTSUPP;
947
948 if (!xenbus_read_unsigned(dev->otherend, "feature-rx-notify", 0)) {
949
950
951
952
953 be->vif->drain_timeout = msecs_to_jiffies(30);
954 be->vif->stall_timeout = 0;
955 }
956
957 vif->can_sg = !!xenbus_read_unsigned(dev->otherend, "feature-sg", 0);
958
959 vif->gso_mask = 0;
960
961 if (xenbus_read_unsigned(dev->otherend, "feature-gso-tcpv4", 0))
962 vif->gso_mask |= GSO_BIT(TCPV4);
963
964 if (xenbus_read_unsigned(dev->otherend, "feature-gso-tcpv6", 0))
965 vif->gso_mask |= GSO_BIT(TCPV6);
966
967 vif->ip_csum = !xenbus_read_unsigned(dev->otherend,
968 "feature-no-csum-offload", 0);
969
970 vif->ipv6_csum = !!xenbus_read_unsigned(dev->otherend,
971 "feature-ipv6-csum-offload", 0);
972
973 read_xenbus_frontend_xdp(be, dev);
974
975 return 0;
976}
977
978static int netback_remove(struct xenbus_device *dev)
979{
980 struct backend_info *be = dev_get_drvdata(&dev->dev);
981
982 unregister_hotplug_status_watch(be);
983 if (be->vif) {
984 kobject_uevent(&dev->dev.kobj, KOBJ_OFFLINE);
985 backend_disconnect(be);
986 xenvif_free(be->vif);
987 be->vif = NULL;
988 }
989 kfree(be->hotplug_script);
990 kfree(be);
991 dev_set_drvdata(&dev->dev, NULL);
992 return 0;
993}
994
995
996
997
998
999static int netback_probe(struct xenbus_device *dev,
1000 const struct xenbus_device_id *id)
1001{
1002 const char *message;
1003 struct xenbus_transaction xbt;
1004 int err;
1005 int sg;
1006 const char *script;
1007 struct backend_info *be = kzalloc(sizeof(*be), GFP_KERNEL);
1008
1009 if (!be) {
1010 xenbus_dev_fatal(dev, -ENOMEM,
1011 "allocating backend structure");
1012 return -ENOMEM;
1013 }
1014
1015 be->dev = dev;
1016 dev_set_drvdata(&dev->dev, be);
1017
1018 sg = 1;
1019
1020 do {
1021 err = xenbus_transaction_start(&xbt);
1022 if (err) {
1023 xenbus_dev_fatal(dev, err, "starting transaction");
1024 goto fail;
1025 }
1026
1027 err = xenbus_printf(xbt, dev->nodename, "feature-sg", "%d", sg);
1028 if (err) {
1029 message = "writing feature-sg";
1030 goto abort_transaction;
1031 }
1032
1033 err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv4",
1034 "%d", sg);
1035 if (err) {
1036 message = "writing feature-gso-tcpv4";
1037 goto abort_transaction;
1038 }
1039
1040 err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv6",
1041 "%d", sg);
1042 if (err) {
1043 message = "writing feature-gso-tcpv6";
1044 goto abort_transaction;
1045 }
1046
1047
1048 err = xenbus_printf(xbt, dev->nodename,
1049 "feature-ipv6-csum-offload",
1050 "%d", 1);
1051 if (err) {
1052 message = "writing feature-ipv6-csum-offload";
1053 goto abort_transaction;
1054 }
1055
1056
1057 err = xenbus_printf(xbt, dev->nodename,
1058 "feature-rx-copy", "%d", 1);
1059 if (err) {
1060 message = "writing feature-rx-copy";
1061 goto abort_transaction;
1062 }
1063
1064
1065 err = xenbus_printf(xbt, dev->nodename,
1066 "feature-xdp-headroom", "%d",
1067 provides_xdp_headroom);
1068 if (err) {
1069 message = "writing feature-xdp-headroom";
1070 goto abort_transaction;
1071 }
1072
1073
1074
1075
1076 err = xenbus_printf(xbt, dev->nodename,
1077 "feature-rx-flip", "%d", 0);
1078 if (err) {
1079 message = "writing feature-rx-flip";
1080 goto abort_transaction;
1081 }
1082
1083
1084 err = xenbus_printf(xbt, dev->nodename,
1085 "feature-multicast-control", "%d", 1);
1086 if (err) {
1087 message = "writing feature-multicast-control";
1088 goto abort_transaction;
1089 }
1090
1091 err = xenbus_printf(xbt, dev->nodename,
1092 "feature-dynamic-multicast-control",
1093 "%d", 1);
1094 if (err) {
1095 message = "writing feature-dynamic-multicast-control";
1096 goto abort_transaction;
1097 }
1098
1099 err = xenbus_transaction_end(xbt, 0);
1100 } while (err == -EAGAIN);
1101
1102 if (err) {
1103 xenbus_dev_fatal(dev, err, "completing transaction");
1104 goto fail;
1105 }
1106
1107
1108
1109
1110 err = xenbus_printf(XBT_NIL, dev->nodename,
1111 "feature-split-event-channels",
1112 "%u", separate_tx_rx_irq);
1113 if (err)
1114 pr_debug("Error writing feature-split-event-channels\n");
1115
1116
1117 err = xenbus_printf(XBT_NIL, dev->nodename,
1118 "multi-queue-max-queues", "%u", xenvif_max_queues);
1119 if (err)
1120 pr_debug("Error writing multi-queue-max-queues\n");
1121
1122 err = xenbus_printf(XBT_NIL, dev->nodename,
1123 "feature-ctrl-ring",
1124 "%u", true);
1125 if (err)
1126 pr_debug("Error writing feature-ctrl-ring\n");
1127
1128 backend_switch_state(be, XenbusStateInitWait);
1129
1130 script = xenbus_read(XBT_NIL, dev->nodename, "script", NULL);
1131 if (IS_ERR(script)) {
1132 err = PTR_ERR(script);
1133 xenbus_dev_fatal(dev, err, "reading script");
1134 goto fail;
1135 }
1136
1137 be->hotplug_script = script;
1138
1139
1140 err = backend_create_xenvif(be);
1141 if (err)
1142 goto fail;
1143
1144 return 0;
1145
1146abort_transaction:
1147 xenbus_transaction_end(xbt, 1);
1148 xenbus_dev_fatal(dev, err, "%s", message);
1149fail:
1150 pr_debug("failed\n");
1151 netback_remove(dev);
1152 return err;
1153}
1154
1155static const struct xenbus_device_id netback_ids[] = {
1156 { "vif" },
1157 { "" }
1158};
1159
1160static struct xenbus_driver netback_driver = {
1161 .ids = netback_ids,
1162 .probe = netback_probe,
1163 .remove = netback_remove,
1164 .uevent = netback_uevent,
1165 .otherend_changed = frontend_changed,
1166 .allow_rebind = true,
1167};
1168
1169int xenvif_xenbus_init(void)
1170{
1171 return xenbus_register_backend(&netback_driver);
1172}
1173
1174void xenvif_xenbus_fini(void)
1175{
1176 return xenbus_unregister_driver(&netback_driver);
1177}
1178
