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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
198/*
199 * Handle the creation of the hotplug script environment. We add the script
200 * and vif variables to the environment, for the benefit of the vif-* hotplug
201 * scripts.
202 */
203static int netback_uevent(const 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 /* CONFIG_DEBUG_FS */
262 xenvif_disconnect_data(vif);
263
264 /* At this point some of the handlers may still be active
265 * so we need to have additional synchronization here.
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 /* If we are waiting for a hotplug script then defer the
295 * actual xenbus state change.
296 */
297 if (!be->have_hotplug_status_watch)
298 xenbus_switch_state(dev, state);
299}
300
301/* Handle backend state transitions:
302 *
303 * The backend state starts in Initialising and the following transitions are
304 * allowed.
305 *
306 * Initialising -> InitWait -> Connected
307 * \
308 * \ ^ \ |
309 * \ | \ |
310 * \ | \ |
311 * \ | \ |
312 * \ | \ |
313 * \ | \ |
314 * V | V V
315 *
316 * Closed <-> Closing
317 *
318 * The state argument specifies the eventual state of the backend and the
319 * function transitions to that state via the shortest path.
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 * Callback received when the frontend's state changes.
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; /* if not online */
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 /* Default to unlimited bandwidth. */
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.will_handle = NULL;
561 vif->credit_watch.callback = xen_net_rate_changed;
562 err = register_xenbus_watch(&vif->credit_watch);
563 if (err) {
564 pr_err("Failed to set watcher %s\n", vif->credit_watch.node);
565 kfree(node);
566 vif->credit_watch.node = NULL;
567 vif->credit_watch.will_handle = NULL;
568 vif->credit_watch.callback = NULL;
569 }
570 return err;
571}
572
573static void xen_unregister_credit_watch(struct xenvif *vif)
574{
575 if (vif->credit_watch.node) {
576 unregister_xenbus_watch(&vif->credit_watch);
577 kfree(vif->credit_watch.node);
578 vif->credit_watch.node = NULL;
579 }
580}
581
582static void xen_mcast_ctrl_changed(struct xenbus_watch *watch,
583 const char *path, const char *token)
584{
585 struct xenvif *vif = container_of(watch, struct xenvif,
586 mcast_ctrl_watch);
587 struct xenbus_device *dev = xenvif_to_xenbus_device(vif);
588
589 vif->multicast_control = !!xenbus_read_unsigned(dev->otherend,
590 "request-multicast-control", 0);
591}
592
593static int xen_register_mcast_ctrl_watch(struct xenbus_device *dev,
594 struct xenvif *vif)
595{
596 int err = 0;
597 char *node;
598 unsigned maxlen = strlen(dev->otherend) +
599 sizeof("/request-multicast-control");
600
601 if (vif->mcast_ctrl_watch.node) {
602 pr_err_ratelimited("Watch is already registered\n");
603 return -EADDRINUSE;
604 }
605
606 node = kmalloc(maxlen, GFP_KERNEL);
607 if (!node) {
608 pr_err("Failed to allocate memory for watch\n");
609 return -ENOMEM;
610 }
611 snprintf(node, maxlen, "%s/request-multicast-control",
612 dev->otherend);
613 vif->mcast_ctrl_watch.node = node;
614 vif->mcast_ctrl_watch.will_handle = NULL;
615 vif->mcast_ctrl_watch.callback = xen_mcast_ctrl_changed;
616 err = register_xenbus_watch(&vif->mcast_ctrl_watch);
617 if (err) {
618 pr_err("Failed to set watcher %s\n",
619 vif->mcast_ctrl_watch.node);
620 kfree(node);
621 vif->mcast_ctrl_watch.node = NULL;
622 vif->mcast_ctrl_watch.will_handle = NULL;
623 vif->mcast_ctrl_watch.callback = NULL;
624 }
625 return err;
626}
627
628static void xen_unregister_mcast_ctrl_watch(struct xenvif *vif)
629{
630 if (vif->mcast_ctrl_watch.node) {
631 unregister_xenbus_watch(&vif->mcast_ctrl_watch);
632 kfree(vif->mcast_ctrl_watch.node);
633 vif->mcast_ctrl_watch.node = NULL;
634 }
635}
636
637static void xen_register_watchers(struct xenbus_device *dev,
638 struct xenvif *vif)
639{
640 xen_register_credit_watch(dev, vif);
641 xen_register_mcast_ctrl_watch(dev, vif);
642}
643
644static void xen_unregister_watchers(struct xenvif *vif)
645{
646 xen_unregister_mcast_ctrl_watch(vif);
647 xen_unregister_credit_watch(vif);
648}
649
650static void unregister_hotplug_status_watch(struct backend_info *be)
651{
652 if (be->have_hotplug_status_watch) {
653 unregister_xenbus_watch(&be->hotplug_status_watch);
654 kfree(be->hotplug_status_watch.node);
655 }
656 be->have_hotplug_status_watch = 0;
657}
658
659static void hotplug_status_changed(struct xenbus_watch *watch,
660 const char *path,
661 const char *token)
662{
663 struct backend_info *be = container_of(watch,
664 struct backend_info,
665 hotplug_status_watch);
666 char *str;
667 unsigned int len;
668
669 str = xenbus_read(XBT_NIL, be->dev->nodename, "hotplug-status", &len);
670 if (IS_ERR(str))
671 return;
672 if (len == sizeof("connected")-1 && !memcmp(str, "connected", len)) {
673 /* Complete any pending state change */
674 xenbus_switch_state(be->dev, be->state);
675
676 /* Not interested in this watch anymore. */
677 unregister_hotplug_status_watch(be);
678 }
679 kfree(str);
680}
681
682static int connect_ctrl_ring(struct backend_info *be)
683{
684 struct xenbus_device *dev = be->dev;
685 struct xenvif *vif = be->vif;
686 unsigned int val;
687 grant_ref_t ring_ref;
688 unsigned int evtchn;
689 int err;
690
691 err = xenbus_scanf(XBT_NIL, dev->otherend,
692 "ctrl-ring-ref", "%u", &val);
693 if (err < 0)
694 goto done; /* The frontend does not have a control ring */
695
696 ring_ref = val;
697
698 err = xenbus_scanf(XBT_NIL, dev->otherend,
699 "event-channel-ctrl", "%u", &val);
700 if (err < 0) {
701 xenbus_dev_fatal(dev, err,
702 "reading %s/event-channel-ctrl",
703 dev->otherend);
704 goto fail;
705 }
706
707 evtchn = val;
708
709 err = xenvif_connect_ctrl(vif, ring_ref, evtchn);
710 if (err) {
711 xenbus_dev_fatal(dev, err,
712 "mapping shared-frame %u port %u",
713 ring_ref, evtchn);
714 goto fail;
715 }
716
717done:
718 return 0;
719
720fail:
721 return err;
722}
723
724static void connect(struct backend_info *be)
725{
726 int err;
727 struct xenbus_device *dev = be->dev;
728 unsigned long credit_bytes, credit_usec;
729 unsigned int queue_index;
730 unsigned int requested_num_queues;
731 struct xenvif_queue *queue;
732
733 /* Check whether the frontend requested multiple queues
734 * and read the number requested.
735 */
736 requested_num_queues = xenbus_read_unsigned(dev->otherend,
737 "multi-queue-num-queues", 1);
738 if (requested_num_queues > xenvif_max_queues) {
739 /* buggy or malicious guest */
740 xenbus_dev_fatal(dev, -EINVAL,
741 "guest requested %u queues, exceeding the maximum of %u.",
742 requested_num_queues, xenvif_max_queues);
743 return;
744 }
745
746 err = xen_net_read_mac(dev, be->vif->fe_dev_addr);
747 if (err) {
748 xenbus_dev_fatal(dev, err, "parsing %s/mac", dev->nodename);
749 return;
750 }
751
752 xen_net_read_rate(dev, &credit_bytes, &credit_usec);
753 xen_unregister_watchers(be->vif);
754 xen_register_watchers(dev, be->vif);
755 read_xenbus_vif_flags(be);
756
757 err = connect_ctrl_ring(be);
758 if (err) {
759 xenbus_dev_fatal(dev, err, "connecting control ring");
760 return;
761 }
762
763 /* Use the number of queues requested by the frontend */
764 be->vif->queues = vzalloc(array_size(requested_num_queues,
765 sizeof(struct xenvif_queue)));
766 if (!be->vif->queues) {
767 xenbus_dev_fatal(dev, -ENOMEM,
768 "allocating queues");
769 return;
770 }
771
772 be->vif->num_queues = requested_num_queues;
773 be->vif->stalled_queues = requested_num_queues;
774
775 for (queue_index = 0; queue_index < requested_num_queues; ++queue_index) {
776 queue = &be->vif->queues[queue_index];
777 queue->vif = be->vif;
778 queue->id = queue_index;
779 snprintf(queue->name, sizeof(queue->name), "%s-q%u",
780 be->vif->dev->name, queue->id);
781
782 err = xenvif_init_queue(queue);
783 if (err) {
784 /* xenvif_init_queue() cleans up after itself on
785 * failure, but we need to clean up any previously
786 * initialised queues. Set num_queues to i so that
787 * earlier queues can be destroyed using the regular
788 * disconnect logic.
789 */
790 be->vif->num_queues = queue_index;
791 goto err;
792 }
793
794 queue->credit_bytes = credit_bytes;
795 queue->remaining_credit = credit_bytes;
796 queue->credit_usec = credit_usec;
797
798 err = connect_data_rings(be, queue);
799 if (err) {
800 /* connect_data_rings() cleans up after itself on
801 * failure, but we need to clean up after
802 * xenvif_init_queue() here, and also clean up any
803 * previously initialised queues.
804 */
805 xenvif_deinit_queue(queue);
806 be->vif->num_queues = queue_index;
807 goto err;
808 }
809 }
810
811#ifdef CONFIG_DEBUG_FS
812 xenvif_debugfs_addif(be->vif);
813#endif /* CONFIG_DEBUG_FS */
814
815 /* Initialisation completed, tell core driver the number of
816 * active queues.
817 */
818 rtnl_lock();
819 netif_set_real_num_tx_queues(be->vif->dev, requested_num_queues);
820 netif_set_real_num_rx_queues(be->vif->dev, requested_num_queues);
821 rtnl_unlock();
822
823 xenvif_carrier_on(be->vif);
824
825 unregister_hotplug_status_watch(be);
826 err = xenbus_watch_pathfmt(dev, &be->hotplug_status_watch, NULL,
827 hotplug_status_changed,
828 "%s/%s", dev->nodename, "hotplug-status");
829 if (!err)
830 be->have_hotplug_status_watch = 1;
831
832 netif_tx_wake_all_queues(be->vif->dev);
833
834 return;
835
836err:
837 if (be->vif->num_queues > 0)
838 xenvif_disconnect_data(be->vif); /* Clean up existing queues */
839 for (queue_index = 0; queue_index < be->vif->num_queues; ++queue_index)
840 xenvif_deinit_queue(&be->vif->queues[queue_index]);
841 vfree(be->vif->queues);
842 be->vif->queues = NULL;
843 be->vif->num_queues = 0;
844 xenvif_disconnect_ctrl(be->vif);
845 return;
846}
847
848
849static int connect_data_rings(struct backend_info *be,
850 struct xenvif_queue *queue)
851{
852 struct xenbus_device *dev = be->dev;
853 unsigned int num_queues = queue->vif->num_queues;
854 unsigned long tx_ring_ref, rx_ring_ref;
855 unsigned int tx_evtchn, rx_evtchn;
856 int err;
857 char *xspath;
858 size_t xspathsize;
859 const size_t xenstore_path_ext_size = 11; /* sufficient for "/queue-NNN" */
860
861 /* If the frontend requested 1 queue, or we have fallen back
862 * to single queue due to lack of frontend support for multi-
863 * queue, expect the remaining XenStore keys in the toplevel
864 * directory. Otherwise, expect them in a subdirectory called
865 * queue-N.
866 */
867 if (num_queues == 1) {
868 xspath = kstrdup(dev->otherend, GFP_KERNEL);
869 if (!xspath) {
870 xenbus_dev_fatal(dev, -ENOMEM,
871 "reading ring references");
872 return -ENOMEM;
873 }
874 } else {
875 xspathsize = strlen(dev->otherend) + xenstore_path_ext_size;
876 xspath = kzalloc(xspathsize, GFP_KERNEL);
877 if (!xspath) {
878 xenbus_dev_fatal(dev, -ENOMEM,
879 "reading ring references");
880 return -ENOMEM;
881 }
882 snprintf(xspath, xspathsize, "%s/queue-%u", dev->otherend,
883 queue->id);
884 }
885
886 err = xenbus_gather(XBT_NIL, xspath,
887 "tx-ring-ref", "%lu", &tx_ring_ref,
888 "rx-ring-ref", "%lu", &rx_ring_ref, NULL);
889 if (err) {
890 xenbus_dev_fatal(dev, err,
891 "reading %s/ring-ref",
892 xspath);
893 goto err;
894 }
895
896 /* Try split event channels first, then single event channel. */
897 err = xenbus_gather(XBT_NIL, xspath,
898 "event-channel-tx", "%u", &tx_evtchn,
899 "event-channel-rx", "%u", &rx_evtchn, NULL);
900 if (err < 0) {
901 err = xenbus_scanf(XBT_NIL, xspath,
902 "event-channel", "%u", &tx_evtchn);
903 if (err < 0) {
904 xenbus_dev_fatal(dev, err,
905 "reading %s/event-channel(-tx/rx)",
906 xspath);
907 goto err;
908 }
909 rx_evtchn = tx_evtchn;
910 }
911
912 /* Map the shared frame, irq etc. */
913 err = xenvif_connect_data(queue, tx_ring_ref, rx_ring_ref,
914 tx_evtchn, rx_evtchn);
915 if (err) {
916 xenbus_dev_fatal(dev, err,
917 "mapping shared-frames %lu/%lu port tx %u rx %u",
918 tx_ring_ref, rx_ring_ref,
919 tx_evtchn, rx_evtchn);
920 goto err;
921 }
922
923 err = 0;
924err: /* Regular return falls through with err == 0 */
925 kfree(xspath);
926 return err;
927}
928
929static int read_xenbus_vif_flags(struct backend_info *be)
930{
931 struct xenvif *vif = be->vif;
932 struct xenbus_device *dev = be->dev;
933 unsigned int rx_copy;
934 int err;
935
936 err = xenbus_scanf(XBT_NIL, dev->otherend, "request-rx-copy", "%u",
937 &rx_copy);
938 if (err == -ENOENT) {
939 err = 0;
940 rx_copy = 0;
941 }
942 if (err < 0) {
943 xenbus_dev_fatal(dev, err, "reading %s/request-rx-copy",
944 dev->otherend);
945 return err;
946 }
947 if (!rx_copy)
948 return -EOPNOTSUPP;
949
950 if (!xenbus_read_unsigned(dev->otherend, "feature-rx-notify", 0)) {
951 /* - Reduce drain timeout to poll more frequently for
952 * Rx requests.
953 * - Disable Rx stall detection.
954 */
955 be->vif->drain_timeout = msecs_to_jiffies(30);
956 be->vif->stall_timeout = 0;
957 }
958
959 vif->can_sg = !!xenbus_read_unsigned(dev->otherend, "feature-sg", 0);
960
961 vif->gso_mask = 0;
962
963 if (xenbus_read_unsigned(dev->otherend, "feature-gso-tcpv4", 0))
964 vif->gso_mask |= GSO_BIT(TCPV4);
965
966 if (xenbus_read_unsigned(dev->otherend, "feature-gso-tcpv6", 0))
967 vif->gso_mask |= GSO_BIT(TCPV6);
968
969 vif->ip_csum = !xenbus_read_unsigned(dev->otherend,
970 "feature-no-csum-offload", 0);
971
972 vif->ipv6_csum = !!xenbus_read_unsigned(dev->otherend,
973 "feature-ipv6-csum-offload", 0);
974
975 read_xenbus_frontend_xdp(be, dev);
976
977 return 0;
978}
979
980static void netback_remove(struct xenbus_device *dev)
981{
982 struct backend_info *be = dev_get_drvdata(&dev->dev);
983
984 unregister_hotplug_status_watch(be);
985 xenbus_rm(XBT_NIL, dev->nodename, "hotplug-status");
986 if (be->vif) {
987 kobject_uevent(&dev->dev.kobj, KOBJ_OFFLINE);
988 backend_disconnect(be);
989 xenvif_free(be->vif);
990 be->vif = NULL;
991 }
992 kfree(be->hotplug_script);
993 kfree(be);
994 dev_set_drvdata(&dev->dev, NULL);
995}
996
997/*
998 * Entry point to this code when a new device is created. Allocate the basic
999 * structures and switch to InitWait.
1000 */
1001static int netback_probe(struct xenbus_device *dev,
1002 const struct xenbus_device_id *id)
1003{
1004 const char *message;
1005 struct xenbus_transaction xbt;
1006 int err;
1007 int sg;
1008 const char *script;
1009 struct backend_info *be = kzalloc(sizeof(*be), GFP_KERNEL);
1010
1011 if (!be) {
1012 xenbus_dev_fatal(dev, -ENOMEM,
1013 "allocating backend structure");
1014 return -ENOMEM;
1015 }
1016
1017 be->dev = dev;
1018 dev_set_drvdata(&dev->dev, be);
1019
1020 sg = 1;
1021
1022 do {
1023 err = xenbus_transaction_start(&xbt);
1024 if (err) {
1025 xenbus_dev_fatal(dev, err, "starting transaction");
1026 goto fail;
1027 }
1028
1029 err = xenbus_printf(xbt, dev->nodename, "feature-sg", "%d", sg);
1030 if (err) {
1031 message = "writing feature-sg";
1032 goto abort_transaction;
1033 }
1034
1035 err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv4",
1036 "%d", sg);
1037 if (err) {
1038 message = "writing feature-gso-tcpv4";
1039 goto abort_transaction;
1040 }
1041
1042 err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv6",
1043 "%d", sg);
1044 if (err) {
1045 message = "writing feature-gso-tcpv6";
1046 goto abort_transaction;
1047 }
1048
1049 /* We support partial checksum setup for IPv6 packets */
1050 err = xenbus_printf(xbt, dev->nodename,
1051 "feature-ipv6-csum-offload",
1052 "%d", 1);
1053 if (err) {
1054 message = "writing feature-ipv6-csum-offload";
1055 goto abort_transaction;
1056 }
1057
1058 /* We support rx-copy path. */
1059 err = xenbus_printf(xbt, dev->nodename,
1060 "feature-rx-copy", "%d", 1);
1061 if (err) {
1062 message = "writing feature-rx-copy";
1063 goto abort_transaction;
1064 }
1065
1066 /* we can adjust a headroom for netfront XDP processing */
1067 err = xenbus_printf(xbt, dev->nodename,
1068 "feature-xdp-headroom", "%d",
1069 provides_xdp_headroom);
1070 if (err) {
1071 message = "writing feature-xdp-headroom";
1072 goto abort_transaction;
1073 }
1074
1075 /* We don't support rx-flip path (except old guests who
1076 * don't grok this feature flag).
1077 */
1078 err = xenbus_printf(xbt, dev->nodename,
1079 "feature-rx-flip", "%d", 0);
1080 if (err) {
1081 message = "writing feature-rx-flip";
1082 goto abort_transaction;
1083 }
1084
1085 /* We support dynamic multicast-control. */
1086 err = xenbus_printf(xbt, dev->nodename,
1087 "feature-multicast-control", "%d", 1);
1088 if (err) {
1089 message = "writing feature-multicast-control";
1090 goto abort_transaction;
1091 }
1092
1093 err = xenbus_printf(xbt, dev->nodename,
1094 "feature-dynamic-multicast-control",
1095 "%d", 1);
1096 if (err) {
1097 message = "writing feature-dynamic-multicast-control";
1098 goto abort_transaction;
1099 }
1100
1101 err = xenbus_transaction_end(xbt, 0);
1102 } while (err == -EAGAIN);
1103
1104 if (err) {
1105 xenbus_dev_fatal(dev, err, "completing transaction");
1106 goto fail;
1107 }
1108
1109 /* Split event channels support, this is optional so it is not
1110 * put inside the above loop.
1111 */
1112 err = xenbus_printf(XBT_NIL, dev->nodename,
1113 "feature-split-event-channels",
1114 "%u", separate_tx_rx_irq);
1115 if (err)
1116 pr_debug("Error writing feature-split-event-channels\n");
1117
1118 /* Multi-queue support: This is an optional feature. */
1119 err = xenbus_printf(XBT_NIL, dev->nodename,
1120 "multi-queue-max-queues", "%u", xenvif_max_queues);
1121 if (err)
1122 pr_debug("Error writing multi-queue-max-queues\n");
1123
1124 err = xenbus_printf(XBT_NIL, dev->nodename,
1125 "feature-ctrl-ring",
1126 "%u", true);
1127 if (err)
1128 pr_debug("Error writing feature-ctrl-ring\n");
1129
1130 backend_switch_state(be, XenbusStateInitWait);
1131
1132 script = xenbus_read(XBT_NIL, dev->nodename, "script", NULL);
1133 if (IS_ERR(script)) {
1134 err = PTR_ERR(script);
1135 xenbus_dev_fatal(dev, err, "reading script");
1136 goto fail;
1137 }
1138
1139 be->hotplug_script = script;
1140
1141 /* This kicks hotplug scripts, so do it immediately. */
1142 err = backend_create_xenvif(be);
1143 if (err)
1144 goto fail;
1145
1146 return 0;
1147
1148abort_transaction:
1149 xenbus_transaction_end(xbt, 1);
1150 xenbus_dev_fatal(dev, err, "%s", message);
1151fail:
1152 pr_debug("failed\n");
1153 netback_remove(dev);
1154 return err;
1155}
1156
1157static const struct xenbus_device_id netback_ids[] = {
1158 { "vif" },
1159 { "" }
1160};
1161
1162static struct xenbus_driver netback_driver = {
1163 .ids = netback_ids,
1164 .probe = netback_probe,
1165 .remove = netback_remove,
1166 .uevent = netback_uevent,
1167 .otherend_changed = frontend_changed,
1168 .allow_rebind = true,
1169};
1170
1171int xenvif_xenbus_init(void)
1172{
1173 return xenbus_register_backend(&netback_driver);
1174}
1175
1176void xenvif_xenbus_fini(void)
1177{
1178 return xenbus_unregister_driver(&netback_driver);
1179}
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}