2 * Xenbus code for netif backend
4 * Copyright (C) 2005 Rusty Russell <rusty@rustcorp.com.au>
5 * Copyright (C) 2005 XenSource Ltd
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.
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.
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/>.
22 #include <linux/vmalloc.h>
23 #include <linux/rtnetlink.h>
26 struct xenbus_device *dev;
29 /* This is the state that will be reflected in xenstore when any
30 * active hotplug script completes.
32 enum xenbus_state state;
34 enum xenbus_state frontend_state;
35 struct xenbus_watch hotplug_status_watch;
36 u8 have_hotplug_status_watch:1;
38 const char *hotplug_script;
41 static int connect_data_rings(struct backend_info *be,
42 struct xenvif_queue *queue);
43 static void connect(struct backend_info *be);
44 static int read_xenbus_vif_flags(struct backend_info *be);
45 static int backend_create_xenvif(struct backend_info *be);
46 static void unregister_hotplug_status_watch(struct backend_info *be);
47 static void xen_unregister_watchers(struct xenvif *vif);
48 static void set_backend_state(struct backend_info *be,
49 enum xenbus_state state);
51 #ifdef CONFIG_DEBUG_FS
52 struct dentry *xen_netback_dbg_root = NULL;
54 static int xenvif_read_io_ring(struct seq_file *m, void *v)
56 struct xenvif_queue *queue = m->private;
57 struct xen_netif_tx_back_ring *tx_ring = &queue->tx;
58 struct xen_netif_rx_back_ring *rx_ring = &queue->rx;
59 struct netdev_queue *dev_queue;
62 struct xen_netif_tx_sring *sring = tx_ring->sring;
64 seq_printf(m, "Queue %d\nTX: nr_ents %u\n", queue->id,
66 seq_printf(m, "req prod %u (%d) cons %u (%d) event %u (%d)\n",
68 sring->req_prod - sring->rsp_prod,
70 tx_ring->req_cons - sring->rsp_prod,
72 sring->req_event - sring->rsp_prod);
73 seq_printf(m, "rsp prod %u (base) pvt %u (%d) event %u (%d)\n",
75 tx_ring->rsp_prod_pvt,
76 tx_ring->rsp_prod_pvt - sring->rsp_prod,
78 sring->rsp_event - sring->rsp_prod);
79 seq_printf(m, "pending prod %u pending cons %u nr_pending_reqs %u\n",
82 nr_pending_reqs(queue));
83 seq_printf(m, "dealloc prod %u dealloc cons %u dealloc_queue %u\n\n",
86 queue->dealloc_prod - queue->dealloc_cons);
90 struct xen_netif_rx_sring *sring = rx_ring->sring;
92 seq_printf(m, "RX: nr_ents %u\n", rx_ring->nr_ents);
93 seq_printf(m, "req prod %u (%d) cons %u (%d) event %u (%d)\n",
95 sring->req_prod - sring->rsp_prod,
97 rx_ring->req_cons - sring->rsp_prod,
99 sring->req_event - sring->rsp_prod);
100 seq_printf(m, "rsp prod %u (base) pvt %u (%d) event %u (%d)\n\n",
102 rx_ring->rsp_prod_pvt,
103 rx_ring->rsp_prod_pvt - sring->rsp_prod,
105 sring->rsp_event - sring->rsp_prod);
108 seq_printf(m, "NAPI state: %lx NAPI weight: %d TX queue len %u\n"
109 "Credit timer_pending: %d, credit: %lu, usec: %lu\n"
110 "remaining: %lu, expires: %lu, now: %lu\n",
111 queue->napi.state, queue->napi.weight,
112 skb_queue_len(&queue->tx_queue),
113 timer_pending(&queue->credit_timeout),
116 queue->remaining_credit,
117 queue->credit_timeout.expires,
120 dev_queue = netdev_get_tx_queue(queue->vif->dev, queue->id);
122 seq_printf(m, "\nRx internal queue: len %u max %u pkts %u %s\n",
123 queue->rx_queue_len, queue->rx_queue_max,
124 skb_queue_len(&queue->rx_queue),
125 netif_tx_queue_stopped(dev_queue) ? "stopped" : "running");
130 #define XENVIF_KICK_STR "kick"
131 #define BUFFER_SIZE 32
134 xenvif_write_io_ring(struct file *filp, const char __user *buf, size_t count,
137 struct xenvif_queue *queue =
138 ((struct seq_file *)filp->private_data)->private;
140 char write[BUFFER_SIZE];
142 /* don't allow partial writes and check the length */
145 if (count >= sizeof(write))
148 len = simple_write_to_buffer(write,
158 if (!strncmp(write, XENVIF_KICK_STR, sizeof(XENVIF_KICK_STR) - 1))
159 xenvif_interrupt(0, (void *)queue);
161 pr_warn("Unknown command to io_ring_q%d. Available: kick\n",
168 static int xenvif_dump_open(struct inode *inode, struct file *filp)
173 if (inode->i_private)
174 queue = inode->i_private;
175 ret = single_open(filp, xenvif_read_io_ring, queue);
176 filp->f_mode |= FMODE_PWRITE;
180 static const struct file_operations xenvif_dbg_io_ring_ops_fops = {
181 .owner = THIS_MODULE,
182 .open = xenvif_dump_open,
185 .release = single_release,
186 .write = xenvif_write_io_ring,
189 static void xenvif_debugfs_addif(struct xenvif *vif)
191 struct dentry *pfile;
194 if (IS_ERR_OR_NULL(xen_netback_dbg_root))
197 vif->xenvif_dbg_root = debugfs_create_dir(vif->dev->name,
198 xen_netback_dbg_root);
199 if (!IS_ERR_OR_NULL(vif->xenvif_dbg_root)) {
200 for (i = 0; i < vif->num_queues; ++i) {
201 char filename[sizeof("io_ring_q") + 4];
203 snprintf(filename, sizeof(filename), "io_ring_q%d", i);
204 pfile = debugfs_create_file(filename,
206 vif->xenvif_dbg_root,
208 &xenvif_dbg_io_ring_ops_fops);
209 if (IS_ERR_OR_NULL(pfile))
210 pr_warn("Creation of io_ring file returned %ld!\n",
214 netdev_warn(vif->dev,
215 "Creation of vif debugfs dir returned %ld!\n",
216 PTR_ERR(vif->xenvif_dbg_root));
219 static void xenvif_debugfs_delif(struct xenvif *vif)
221 if (IS_ERR_OR_NULL(xen_netback_dbg_root))
224 if (!IS_ERR_OR_NULL(vif->xenvif_dbg_root))
225 debugfs_remove_recursive(vif->xenvif_dbg_root);
226 vif->xenvif_dbg_root = NULL;
228 #endif /* CONFIG_DEBUG_FS */
230 static int netback_remove(struct xenbus_device *dev)
232 struct backend_info *be = dev_get_drvdata(&dev->dev);
234 set_backend_state(be, XenbusStateClosed);
236 unregister_hotplug_status_watch(be);
238 kobject_uevent(&dev->dev.kobj, KOBJ_OFFLINE);
239 xen_unregister_watchers(be->vif);
240 xenbus_rm(XBT_NIL, dev->nodename, "hotplug-status");
241 xenvif_free(be->vif);
244 kfree(be->hotplug_script);
246 dev_set_drvdata(&dev->dev, NULL);
252 * Entry point to this code when a new device is created. Allocate the basic
253 * structures and switch to InitWait.
255 static int netback_probe(struct xenbus_device *dev,
256 const struct xenbus_device_id *id)
259 struct xenbus_transaction xbt;
263 struct backend_info *be = kzalloc(sizeof(struct backend_info),
266 xenbus_dev_fatal(dev, -ENOMEM,
267 "allocating backend structure");
272 dev_set_drvdata(&dev->dev, be);
274 be->state = XenbusStateInitialising;
275 err = xenbus_switch_state(dev, XenbusStateInitialising);
282 err = xenbus_transaction_start(&xbt);
284 xenbus_dev_fatal(dev, err, "starting transaction");
288 err = xenbus_printf(xbt, dev->nodename, "feature-sg", "%d", sg);
290 message = "writing feature-sg";
291 goto abort_transaction;
294 err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv4",
297 message = "writing feature-gso-tcpv4";
298 goto abort_transaction;
301 err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv6",
304 message = "writing feature-gso-tcpv6";
305 goto abort_transaction;
308 /* We support partial checksum setup for IPv6 packets */
309 err = xenbus_printf(xbt, dev->nodename,
310 "feature-ipv6-csum-offload",
313 message = "writing feature-ipv6-csum-offload";
314 goto abort_transaction;
317 /* We support rx-copy path. */
318 err = xenbus_printf(xbt, dev->nodename,
319 "feature-rx-copy", "%d", 1);
321 message = "writing feature-rx-copy";
322 goto abort_transaction;
326 * We don't support rx-flip path (except old guests who don't
327 * grok this feature flag).
329 err = xenbus_printf(xbt, dev->nodename,
330 "feature-rx-flip", "%d", 0);
332 message = "writing feature-rx-flip";
333 goto abort_transaction;
336 /* We support dynamic multicast-control. */
337 err = xenbus_printf(xbt, dev->nodename,
338 "feature-multicast-control", "%d", 1);
340 message = "writing feature-multicast-control";
341 goto abort_transaction;
344 err = xenbus_printf(xbt, dev->nodename,
345 "feature-dynamic-multicast-control",
348 message = "writing feature-dynamic-multicast-control";
349 goto abort_transaction;
352 err = xenbus_transaction_end(xbt, 0);
353 } while (err == -EAGAIN);
356 xenbus_dev_fatal(dev, err, "completing transaction");
361 * Split event channels support, this is optional so it is not
362 * put inside the above loop.
364 err = xenbus_printf(XBT_NIL, dev->nodename,
365 "feature-split-event-channels",
366 "%u", separate_tx_rx_irq);
368 pr_debug("Error writing feature-split-event-channels\n");
370 /* Multi-queue support: This is an optional feature. */
371 err = xenbus_printf(XBT_NIL, dev->nodename,
372 "multi-queue-max-queues", "%u", xenvif_max_queues);
374 pr_debug("Error writing multi-queue-max-queues\n");
376 err = xenbus_printf(XBT_NIL, dev->nodename,
380 pr_debug("Error writing feature-ctrl-ring\n");
382 script = xenbus_read(XBT_NIL, dev->nodename, "script", NULL);
383 if (IS_ERR(script)) {
384 err = PTR_ERR(script);
385 xenbus_dev_fatal(dev, err, "reading script");
389 be->hotplug_script = script;
392 /* This kicks hotplug scripts, so do it immediately. */
393 err = backend_create_xenvif(be);
400 xenbus_transaction_end(xbt, 1);
401 xenbus_dev_fatal(dev, err, "%s", message);
403 pr_debug("failed\n");
410 * Handle the creation of the hotplug script environment. We add the script
411 * and vif variables to the environment, for the benefit of the vif-* hotplug
414 static int netback_uevent(struct xenbus_device *xdev,
415 struct kobj_uevent_env *env)
417 struct backend_info *be = dev_get_drvdata(&xdev->dev);
422 if (add_uevent_var(env, "script=%s", be->hotplug_script))
428 return add_uevent_var(env, "vif=%s", be->vif->dev->name);
432 static int backend_create_xenvif(struct backend_info *be)
436 struct xenbus_device *dev = be->dev;
442 err = xenbus_scanf(XBT_NIL, dev->nodename, "handle", "%li", &handle);
444 xenbus_dev_fatal(dev, err, "reading handle");
445 return (err < 0) ? err : -EINVAL;
448 vif = xenvif_alloc(&dev->dev, dev->otherend_id, handle);
451 xenbus_dev_fatal(dev, err, "creating interface");
456 kobject_uevent(&dev->dev.kobj, KOBJ_ONLINE);
460 static void backend_disconnect(struct backend_info *be)
463 xen_unregister_watchers(be->vif);
464 #ifdef CONFIG_DEBUG_FS
465 xenvif_debugfs_delif(be->vif);
466 #endif /* CONFIG_DEBUG_FS */
467 xenvif_disconnect_data(be->vif);
468 xenvif_disconnect_ctrl(be->vif);
472 static void backend_connect(struct backend_info *be)
478 static inline void backend_switch_state(struct backend_info *be,
479 enum xenbus_state state)
481 struct xenbus_device *dev = be->dev;
483 pr_debug("%s -> %s\n", dev->nodename, xenbus_strstate(state));
486 /* If we are waiting for a hotplug script then defer the
487 * actual xenbus state change.
489 if (!be->have_hotplug_status_watch)
490 xenbus_switch_state(dev, state);
493 /* Handle backend state transitions:
495 * The backend state starts in Initialising and the following transitions are
498 * Initialising -> InitWait -> Connected
510 * The state argument specifies the eventual state of the backend and the
511 * function transitions to that state via the shortest path.
513 static void set_backend_state(struct backend_info *be,
514 enum xenbus_state state)
516 while (be->state != state) {
518 case XenbusStateInitialising:
520 case XenbusStateInitWait:
521 case XenbusStateConnected:
522 case XenbusStateClosing:
523 backend_switch_state(be, XenbusStateInitWait);
525 case XenbusStateClosed:
526 backend_switch_state(be, XenbusStateClosed);
532 case XenbusStateClosed:
534 case XenbusStateInitWait:
535 case XenbusStateConnected:
536 backend_switch_state(be, XenbusStateInitWait);
538 case XenbusStateClosing:
539 backend_switch_state(be, XenbusStateClosing);
545 case XenbusStateInitWait:
547 case XenbusStateConnected:
549 backend_switch_state(be, XenbusStateConnected);
551 case XenbusStateClosing:
552 case XenbusStateClosed:
553 backend_switch_state(be, XenbusStateClosing);
559 case XenbusStateConnected:
561 case XenbusStateInitWait:
562 case XenbusStateClosing:
563 case XenbusStateClosed:
564 backend_disconnect(be);
565 backend_switch_state(be, XenbusStateClosing);
571 case XenbusStateClosing:
573 case XenbusStateInitWait:
574 case XenbusStateConnected:
575 case XenbusStateClosed:
576 backend_switch_state(be, XenbusStateClosed);
589 * Callback received when the frontend's state changes.
591 static void frontend_changed(struct xenbus_device *dev,
592 enum xenbus_state frontend_state)
594 struct backend_info *be = dev_get_drvdata(&dev->dev);
596 pr_debug("%s -> %s\n", dev->otherend, xenbus_strstate(frontend_state));
598 be->frontend_state = frontend_state;
600 switch (frontend_state) {
601 case XenbusStateInitialising:
602 set_backend_state(be, XenbusStateInitWait);
605 case XenbusStateInitialised:
608 case XenbusStateConnected:
609 set_backend_state(be, XenbusStateConnected);
612 case XenbusStateClosing:
613 set_backend_state(be, XenbusStateClosing);
616 case XenbusStateClosed:
617 set_backend_state(be, XenbusStateClosed);
618 if (xenbus_dev_is_online(dev))
620 /* fall through if not online */
621 case XenbusStateUnknown:
622 set_backend_state(be, XenbusStateClosed);
623 device_unregister(&dev->dev);
627 xenbus_dev_fatal(dev, -EINVAL, "saw state %d at frontend",
634 static void xen_net_read_rate(struct xenbus_device *dev,
635 unsigned long *bytes, unsigned long *usec)
641 /* Default to unlimited bandwidth. */
645 ratestr = xenbus_read(XBT_NIL, dev->nodename, "rate", NULL);
650 b = simple_strtoul(s, &e, 10);
651 if ((s == e) || (*e != ','))
655 u = simple_strtoul(s, &e, 10);
656 if ((s == e) || (*e != '\0'))
666 pr_warn("Failed to parse network rate limit. Traffic unlimited.\n");
670 static int xen_net_read_mac(struct xenbus_device *dev, u8 mac[])
672 char *s, *e, *macstr;
675 macstr = s = xenbus_read(XBT_NIL, dev->nodename, "mac", NULL);
677 return PTR_ERR(macstr);
679 for (i = 0; i < ETH_ALEN; i++) {
680 mac[i] = simple_strtoul(s, &e, 16);
681 if ((s == e) || (*e != ((i == ETH_ALEN-1) ? '\0' : ':'))) {
692 static void xen_net_rate_changed(struct xenbus_watch *watch,
693 const char **vec, unsigned int len)
695 struct xenvif *vif = container_of(watch, struct xenvif, credit_watch);
696 struct xenbus_device *dev = xenvif_to_xenbus_device(vif);
697 unsigned long credit_bytes;
698 unsigned long credit_usec;
699 unsigned int queue_index;
701 xen_net_read_rate(dev, &credit_bytes, &credit_usec);
702 for (queue_index = 0; queue_index < vif->num_queues; queue_index++) {
703 struct xenvif_queue *queue = &vif->queues[queue_index];
705 queue->credit_bytes = credit_bytes;
706 queue->credit_usec = credit_usec;
707 if (!mod_timer_pending(&queue->credit_timeout, jiffies) &&
708 queue->remaining_credit > queue->credit_bytes) {
709 queue->remaining_credit = queue->credit_bytes;
714 static int xen_register_credit_watch(struct xenbus_device *dev,
719 unsigned maxlen = strlen(dev->nodename) + sizeof("/rate");
721 if (vif->credit_watch.node)
724 node = kmalloc(maxlen, GFP_KERNEL);
727 snprintf(node, maxlen, "%s/rate", dev->nodename);
728 vif->credit_watch.node = node;
729 vif->credit_watch.callback = xen_net_rate_changed;
730 err = register_xenbus_watch(&vif->credit_watch);
732 pr_err("Failed to set watcher %s\n", vif->credit_watch.node);
734 vif->credit_watch.node = NULL;
735 vif->credit_watch.callback = NULL;
740 static void xen_unregister_credit_watch(struct xenvif *vif)
742 if (vif->credit_watch.node) {
743 unregister_xenbus_watch(&vif->credit_watch);
744 kfree(vif->credit_watch.node);
745 vif->credit_watch.node = NULL;
749 static void xen_mcast_ctrl_changed(struct xenbus_watch *watch,
750 const char **vec, unsigned int len)
752 struct xenvif *vif = container_of(watch, struct xenvif,
754 struct xenbus_device *dev = xenvif_to_xenbus_device(vif);
757 if (xenbus_scanf(XBT_NIL, dev->otherend,
758 "request-multicast-control", "%d", &val) < 0)
760 vif->multicast_control = !!val;
763 static int xen_register_mcast_ctrl_watch(struct xenbus_device *dev,
768 unsigned maxlen = strlen(dev->otherend) +
769 sizeof("/request-multicast-control");
771 if (vif->mcast_ctrl_watch.node) {
772 pr_err_ratelimited("Watch is already registered\n");
776 node = kmalloc(maxlen, GFP_KERNEL);
778 pr_err("Failed to allocate memory for watch\n");
781 snprintf(node, maxlen, "%s/request-multicast-control",
783 vif->mcast_ctrl_watch.node = node;
784 vif->mcast_ctrl_watch.callback = xen_mcast_ctrl_changed;
785 err = register_xenbus_watch(&vif->mcast_ctrl_watch);
787 pr_err("Failed to set watcher %s\n",
788 vif->mcast_ctrl_watch.node);
790 vif->mcast_ctrl_watch.node = NULL;
791 vif->mcast_ctrl_watch.callback = NULL;
796 static void xen_unregister_mcast_ctrl_watch(struct xenvif *vif)
798 if (vif->mcast_ctrl_watch.node) {
799 unregister_xenbus_watch(&vif->mcast_ctrl_watch);
800 kfree(vif->mcast_ctrl_watch.node);
801 vif->mcast_ctrl_watch.node = NULL;
805 static void xen_register_watchers(struct xenbus_device *dev,
808 xen_register_credit_watch(dev, vif);
809 xen_register_mcast_ctrl_watch(dev, vif);
812 static void xen_unregister_watchers(struct xenvif *vif)
814 xen_unregister_mcast_ctrl_watch(vif);
815 xen_unregister_credit_watch(vif);
818 static void unregister_hotplug_status_watch(struct backend_info *be)
820 if (be->have_hotplug_status_watch) {
821 unregister_xenbus_watch(&be->hotplug_status_watch);
822 kfree(be->hotplug_status_watch.node);
824 be->have_hotplug_status_watch = 0;
827 static void hotplug_status_changed(struct xenbus_watch *watch,
829 unsigned int vec_size)
831 struct backend_info *be = container_of(watch,
833 hotplug_status_watch);
837 str = xenbus_read(XBT_NIL, be->dev->nodename, "hotplug-status", &len);
840 if (len == sizeof("connected")-1 && !memcmp(str, "connected", len)) {
841 /* Complete any pending state change */
842 xenbus_switch_state(be->dev, be->state);
844 /* Not interested in this watch anymore. */
845 unregister_hotplug_status_watch(be);
850 static int connect_ctrl_ring(struct backend_info *be)
852 struct xenbus_device *dev = be->dev;
853 struct xenvif *vif = be->vif;
855 grant_ref_t ring_ref;
859 err = xenbus_gather(XBT_NIL, dev->otherend,
860 "ctrl-ring-ref", "%u", &val, NULL);
862 goto done; /* The frontend does not have a control ring */
866 err = xenbus_gather(XBT_NIL, dev->otherend,
867 "event-channel-ctrl", "%u", &val, NULL);
869 xenbus_dev_fatal(dev, err,
870 "reading %s/event-channel-ctrl",
877 err = xenvif_connect_ctrl(vif, ring_ref, evtchn);
879 xenbus_dev_fatal(dev, err,
880 "mapping shared-frame %u port %u",
892 static void connect(struct backend_info *be)
895 struct xenbus_device *dev = be->dev;
896 unsigned long credit_bytes, credit_usec;
897 unsigned int queue_index;
898 unsigned int requested_num_queues;
899 struct xenvif_queue *queue;
901 /* Check whether the frontend requested multiple queues
902 * and read the number requested.
904 err = xenbus_scanf(XBT_NIL, dev->otherend,
905 "multi-queue-num-queues",
906 "%u", &requested_num_queues);
908 requested_num_queues = 1; /* Fall back to single queue */
909 } else if (requested_num_queues > xenvif_max_queues) {
910 /* buggy or malicious guest */
911 xenbus_dev_fatal(dev, err,
912 "guest requested %u queues, exceeding the maximum of %u.",
913 requested_num_queues, xenvif_max_queues);
917 err = xen_net_read_mac(dev, be->vif->fe_dev_addr);
919 xenbus_dev_fatal(dev, err, "parsing %s/mac", dev->nodename);
923 xen_net_read_rate(dev, &credit_bytes, &credit_usec);
924 xen_unregister_watchers(be->vif);
925 xen_register_watchers(dev, be->vif);
926 read_xenbus_vif_flags(be);
928 err = connect_ctrl_ring(be);
930 xenbus_dev_fatal(dev, err, "connecting control ring");
934 /* Use the number of queues requested by the frontend */
935 be->vif->queues = vzalloc(requested_num_queues *
936 sizeof(struct xenvif_queue));
937 if (!be->vif->queues) {
938 xenbus_dev_fatal(dev, -ENOMEM,
939 "allocating queues");
943 be->vif->num_queues = requested_num_queues;
944 be->vif->stalled_queues = requested_num_queues;
946 for (queue_index = 0; queue_index < requested_num_queues; ++queue_index) {
947 queue = &be->vif->queues[queue_index];
948 queue->vif = be->vif;
949 queue->id = queue_index;
950 snprintf(queue->name, sizeof(queue->name), "%s-q%u",
951 be->vif->dev->name, queue->id);
953 err = xenvif_init_queue(queue);
955 /* xenvif_init_queue() cleans up after itself on
956 * failure, but we need to clean up any previously
957 * initialised queues. Set num_queues to i so that
958 * earlier queues can be destroyed using the regular
961 be->vif->num_queues = queue_index;
965 queue->credit_bytes = credit_bytes;
966 queue->remaining_credit = credit_bytes;
967 queue->credit_usec = credit_usec;
969 err = connect_data_rings(be, queue);
971 /* connect_data_rings() cleans up after itself on
972 * failure, but we need to clean up after
973 * xenvif_init_queue() here, and also clean up any
974 * previously initialised queues.
976 xenvif_deinit_queue(queue);
977 be->vif->num_queues = queue_index;
982 #ifdef CONFIG_DEBUG_FS
983 xenvif_debugfs_addif(be->vif);
984 #endif /* CONFIG_DEBUG_FS */
986 /* Initialisation completed, tell core driver the number of
990 netif_set_real_num_tx_queues(be->vif->dev, requested_num_queues);
991 netif_set_real_num_rx_queues(be->vif->dev, requested_num_queues);
994 xenvif_carrier_on(be->vif);
996 unregister_hotplug_status_watch(be);
997 err = xenbus_watch_pathfmt(dev, &be->hotplug_status_watch,
998 hotplug_status_changed,
999 "%s/%s", dev->nodename, "hotplug-status");
1001 be->have_hotplug_status_watch = 1;
1003 netif_tx_wake_all_queues(be->vif->dev);
1008 if (be->vif->num_queues > 0)
1009 xenvif_disconnect_data(be->vif); /* Clean up existing queues */
1010 vfree(be->vif->queues);
1011 be->vif->queues = NULL;
1012 be->vif->num_queues = 0;
1013 xenvif_disconnect_ctrl(be->vif);
1018 static int connect_data_rings(struct backend_info *be,
1019 struct xenvif_queue *queue)
1021 struct xenbus_device *dev = be->dev;
1022 unsigned int num_queues = queue->vif->num_queues;
1023 unsigned long tx_ring_ref, rx_ring_ref;
1024 unsigned int tx_evtchn, rx_evtchn;
1028 const size_t xenstore_path_ext_size = 11; /* sufficient for "/queue-NNN" */
1030 /* If the frontend requested 1 queue, or we have fallen back
1031 * to single queue due to lack of frontend support for multi-
1032 * queue, expect the remaining XenStore keys in the toplevel
1033 * directory. Otherwise, expect them in a subdirectory called
1036 if (num_queues == 1) {
1037 xspath = kzalloc(strlen(dev->otherend) + 1, GFP_KERNEL);
1039 xenbus_dev_fatal(dev, -ENOMEM,
1040 "reading ring references");
1043 strcpy(xspath, dev->otherend);
1045 xspathsize = strlen(dev->otherend) + xenstore_path_ext_size;
1046 xspath = kzalloc(xspathsize, GFP_KERNEL);
1048 xenbus_dev_fatal(dev, -ENOMEM,
1049 "reading ring references");
1052 snprintf(xspath, xspathsize, "%s/queue-%u", dev->otherend,
1056 err = xenbus_gather(XBT_NIL, xspath,
1057 "tx-ring-ref", "%lu", &tx_ring_ref,
1058 "rx-ring-ref", "%lu", &rx_ring_ref, NULL);
1060 xenbus_dev_fatal(dev, err,
1061 "reading %s/ring-ref",
1066 /* Try split event channels first, then single event channel. */
1067 err = xenbus_gather(XBT_NIL, xspath,
1068 "event-channel-tx", "%u", &tx_evtchn,
1069 "event-channel-rx", "%u", &rx_evtchn, NULL);
1071 err = xenbus_scanf(XBT_NIL, xspath,
1072 "event-channel", "%u", &tx_evtchn);
1074 xenbus_dev_fatal(dev, err,
1075 "reading %s/event-channel(-tx/rx)",
1079 rx_evtchn = tx_evtchn;
1082 /* Map the shared frame, irq etc. */
1083 err = xenvif_connect_data(queue, tx_ring_ref, rx_ring_ref,
1084 tx_evtchn, rx_evtchn);
1086 xenbus_dev_fatal(dev, err,
1087 "mapping shared-frames %lu/%lu port tx %u rx %u",
1088 tx_ring_ref, rx_ring_ref,
1089 tx_evtchn, rx_evtchn);
1094 err: /* Regular return falls through with err == 0 */
1099 static int read_xenbus_vif_flags(struct backend_info *be)
1101 struct xenvif *vif = be->vif;
1102 struct xenbus_device *dev = be->dev;
1103 unsigned int rx_copy;
1106 err = xenbus_scanf(XBT_NIL, dev->otherend, "request-rx-copy", "%u",
1108 if (err == -ENOENT) {
1113 xenbus_dev_fatal(dev, err, "reading %s/request-rx-copy",
1120 if (xenbus_scanf(XBT_NIL, dev->otherend,
1121 "feature-rx-notify", "%d", &val) < 0)
1124 /* - Reduce drain timeout to poll more frequently for
1126 * - Disable Rx stall detection.
1128 be->vif->drain_timeout = msecs_to_jiffies(30);
1129 be->vif->stall_timeout = 0;
1132 if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-sg",
1135 vif->can_sg = !!val;
1138 vif->gso_prefix_mask = 0;
1140 if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-gso-tcpv4",
1144 vif->gso_mask |= GSO_BIT(TCPV4);
1146 if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-gso-tcpv4-prefix",
1150 vif->gso_prefix_mask |= GSO_BIT(TCPV4);
1152 if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-gso-tcpv6",
1156 vif->gso_mask |= GSO_BIT(TCPV6);
1158 if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-gso-tcpv6-prefix",
1162 vif->gso_prefix_mask |= GSO_BIT(TCPV6);
1164 if (vif->gso_mask & vif->gso_prefix_mask) {
1165 xenbus_dev_fatal(dev, err,
1166 "%s: gso and gso prefix flags are not "
1167 "mutually exclusive",
1172 if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-no-csum-offload",
1175 vif->ip_csum = !val;
1177 if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-ipv6-csum-offload",
1180 vif->ipv6_csum = !!val;
1185 static const struct xenbus_device_id netback_ids[] = {
1190 static struct xenbus_driver netback_driver = {
1192 .probe = netback_probe,
1193 .remove = netback_remove,
1194 .uevent = netback_uevent,
1195 .otherend_changed = frontend_changed,
1198 int xenvif_xenbus_init(void)
1200 return xenbus_register_backend(&netback_driver);
1203 void xenvif_xenbus_fini(void)
1205 return xenbus_unregister_driver(&netback_driver);