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_io_ring_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_io_ring_open,
185 .release = single_release,
186 .write = xenvif_write_io_ring,
189 static int xenvif_read_ctrl(struct seq_file *m, void *v)
191 struct xenvif *vif = m->private;
193 xenvif_dump_hash_info(vif, m);
198 static int xenvif_ctrl_open(struct inode *inode, struct file *filp)
200 return single_open(filp, xenvif_read_ctrl, inode->i_private);
203 static const struct file_operations xenvif_dbg_ctrl_ops_fops = {
204 .owner = THIS_MODULE,
205 .open = xenvif_ctrl_open,
208 .release = single_release,
211 static void xenvif_debugfs_addif(struct xenvif *vif)
213 struct dentry *pfile;
216 if (IS_ERR_OR_NULL(xen_netback_dbg_root))
219 vif->xenvif_dbg_root = debugfs_create_dir(vif->dev->name,
220 xen_netback_dbg_root);
221 if (!IS_ERR_OR_NULL(vif->xenvif_dbg_root)) {
222 for (i = 0; i < vif->num_queues; ++i) {
223 char filename[sizeof("io_ring_q") + 4];
225 snprintf(filename, sizeof(filename), "io_ring_q%d", i);
226 pfile = debugfs_create_file(filename,
228 vif->xenvif_dbg_root,
230 &xenvif_dbg_io_ring_ops_fops);
231 if (IS_ERR_OR_NULL(pfile))
232 pr_warn("Creation of io_ring file returned %ld!\n",
237 pfile = debugfs_create_file("ctrl",
239 vif->xenvif_dbg_root,
241 &xenvif_dbg_ctrl_ops_fops);
242 if (IS_ERR_OR_NULL(pfile))
243 pr_warn("Creation of ctrl file returned %ld!\n",
247 netdev_warn(vif->dev,
248 "Creation of vif debugfs dir returned %ld!\n",
249 PTR_ERR(vif->xenvif_dbg_root));
252 static void xenvif_debugfs_delif(struct xenvif *vif)
254 if (IS_ERR_OR_NULL(xen_netback_dbg_root))
257 if (!IS_ERR_OR_NULL(vif->xenvif_dbg_root))
258 debugfs_remove_recursive(vif->xenvif_dbg_root);
259 vif->xenvif_dbg_root = NULL;
261 #endif /* CONFIG_DEBUG_FS */
263 static int netback_remove(struct xenbus_device *dev)
265 struct backend_info *be = dev_get_drvdata(&dev->dev);
267 set_backend_state(be, XenbusStateClosed);
269 unregister_hotplug_status_watch(be);
271 kobject_uevent(&dev->dev.kobj, KOBJ_OFFLINE);
272 xen_unregister_watchers(be->vif);
273 xenbus_rm(XBT_NIL, dev->nodename, "hotplug-status");
274 xenvif_free(be->vif);
277 kfree(be->hotplug_script);
279 dev_set_drvdata(&dev->dev, NULL);
285 * Entry point to this code when a new device is created. Allocate the basic
286 * structures and switch to InitWait.
288 static int netback_probe(struct xenbus_device *dev,
289 const struct xenbus_device_id *id)
292 struct xenbus_transaction xbt;
296 struct backend_info *be = kzalloc(sizeof(struct backend_info),
299 xenbus_dev_fatal(dev, -ENOMEM,
300 "allocating backend structure");
305 dev_set_drvdata(&dev->dev, be);
307 be->state = XenbusStateInitialising;
308 err = xenbus_switch_state(dev, XenbusStateInitialising);
315 err = xenbus_transaction_start(&xbt);
317 xenbus_dev_fatal(dev, err, "starting transaction");
321 err = xenbus_printf(xbt, dev->nodename, "feature-sg", "%d", sg);
323 message = "writing feature-sg";
324 goto abort_transaction;
327 err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv4",
330 message = "writing feature-gso-tcpv4";
331 goto abort_transaction;
334 err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv6",
337 message = "writing feature-gso-tcpv6";
338 goto abort_transaction;
341 /* We support partial checksum setup for IPv6 packets */
342 err = xenbus_printf(xbt, dev->nodename,
343 "feature-ipv6-csum-offload",
346 message = "writing feature-ipv6-csum-offload";
347 goto abort_transaction;
350 /* We support rx-copy path. */
351 err = xenbus_printf(xbt, dev->nodename,
352 "feature-rx-copy", "%d", 1);
354 message = "writing feature-rx-copy";
355 goto abort_transaction;
359 * We don't support rx-flip path (except old guests who don't
360 * grok this feature flag).
362 err = xenbus_printf(xbt, dev->nodename,
363 "feature-rx-flip", "%d", 0);
365 message = "writing feature-rx-flip";
366 goto abort_transaction;
369 /* We support dynamic multicast-control. */
370 err = xenbus_printf(xbt, dev->nodename,
371 "feature-multicast-control", "%d", 1);
373 message = "writing feature-multicast-control";
374 goto abort_transaction;
377 err = xenbus_printf(xbt, dev->nodename,
378 "feature-dynamic-multicast-control",
381 message = "writing feature-dynamic-multicast-control";
382 goto abort_transaction;
385 err = xenbus_transaction_end(xbt, 0);
386 } while (err == -EAGAIN);
389 xenbus_dev_fatal(dev, err, "completing transaction");
394 * Split event channels support, this is optional so it is not
395 * put inside the above loop.
397 err = xenbus_printf(XBT_NIL, dev->nodename,
398 "feature-split-event-channels",
399 "%u", separate_tx_rx_irq);
401 pr_debug("Error writing feature-split-event-channels\n");
403 /* Multi-queue support: This is an optional feature. */
404 err = xenbus_printf(XBT_NIL, dev->nodename,
405 "multi-queue-max-queues", "%u", xenvif_max_queues);
407 pr_debug("Error writing multi-queue-max-queues\n");
409 err = xenbus_printf(XBT_NIL, dev->nodename,
413 pr_debug("Error writing feature-ctrl-ring\n");
415 script = xenbus_read(XBT_NIL, dev->nodename, "script", NULL);
416 if (IS_ERR(script)) {
417 err = PTR_ERR(script);
418 xenbus_dev_fatal(dev, err, "reading script");
422 be->hotplug_script = script;
425 /* This kicks hotplug scripts, so do it immediately. */
426 err = backend_create_xenvif(be);
433 xenbus_transaction_end(xbt, 1);
434 xenbus_dev_fatal(dev, err, "%s", message);
436 pr_debug("failed\n");
443 * Handle the creation of the hotplug script environment. We add the script
444 * and vif variables to the environment, for the benefit of the vif-* hotplug
447 static int netback_uevent(struct xenbus_device *xdev,
448 struct kobj_uevent_env *env)
450 struct backend_info *be = dev_get_drvdata(&xdev->dev);
455 if (add_uevent_var(env, "script=%s", be->hotplug_script))
461 return add_uevent_var(env, "vif=%s", be->vif->dev->name);
465 static int backend_create_xenvif(struct backend_info *be)
469 struct xenbus_device *dev = be->dev;
475 err = xenbus_scanf(XBT_NIL, dev->nodename, "handle", "%li", &handle);
477 xenbus_dev_fatal(dev, err, "reading handle");
478 return (err < 0) ? err : -EINVAL;
481 vif = xenvif_alloc(&dev->dev, dev->otherend_id, handle);
484 xenbus_dev_fatal(dev, err, "creating interface");
489 kobject_uevent(&dev->dev.kobj, KOBJ_ONLINE);
493 static void backend_disconnect(struct backend_info *be)
496 xen_unregister_watchers(be->vif);
497 #ifdef CONFIG_DEBUG_FS
498 xenvif_debugfs_delif(be->vif);
499 #endif /* CONFIG_DEBUG_FS */
500 xenvif_disconnect_data(be->vif);
501 xenvif_disconnect_ctrl(be->vif);
505 static void backend_connect(struct backend_info *be)
511 static inline void backend_switch_state(struct backend_info *be,
512 enum xenbus_state state)
514 struct xenbus_device *dev = be->dev;
516 pr_debug("%s -> %s\n", dev->nodename, xenbus_strstate(state));
519 /* If we are waiting for a hotplug script then defer the
520 * actual xenbus state change.
522 if (!be->have_hotplug_status_watch)
523 xenbus_switch_state(dev, state);
526 /* Handle backend state transitions:
528 * The backend state starts in Initialising and the following transitions are
531 * Initialising -> InitWait -> Connected
543 * The state argument specifies the eventual state of the backend and the
544 * function transitions to that state via the shortest path.
546 static void set_backend_state(struct backend_info *be,
547 enum xenbus_state state)
549 while (be->state != state) {
551 case XenbusStateInitialising:
553 case XenbusStateInitWait:
554 case XenbusStateConnected:
555 case XenbusStateClosing:
556 backend_switch_state(be, XenbusStateInitWait);
558 case XenbusStateClosed:
559 backend_switch_state(be, XenbusStateClosed);
565 case XenbusStateClosed:
567 case XenbusStateInitWait:
568 case XenbusStateConnected:
569 backend_switch_state(be, XenbusStateInitWait);
571 case XenbusStateClosing:
572 backend_switch_state(be, XenbusStateClosing);
578 case XenbusStateInitWait:
580 case XenbusStateConnected:
582 backend_switch_state(be, XenbusStateConnected);
584 case XenbusStateClosing:
585 case XenbusStateClosed:
586 backend_switch_state(be, XenbusStateClosing);
592 case XenbusStateConnected:
594 case XenbusStateInitWait:
595 case XenbusStateClosing:
596 case XenbusStateClosed:
597 backend_disconnect(be);
598 backend_switch_state(be, XenbusStateClosing);
604 case XenbusStateClosing:
606 case XenbusStateInitWait:
607 case XenbusStateConnected:
608 case XenbusStateClosed:
609 backend_switch_state(be, XenbusStateClosed);
622 * Callback received when the frontend's state changes.
624 static void frontend_changed(struct xenbus_device *dev,
625 enum xenbus_state frontend_state)
627 struct backend_info *be = dev_get_drvdata(&dev->dev);
629 pr_debug("%s -> %s\n", dev->otherend, xenbus_strstate(frontend_state));
631 be->frontend_state = frontend_state;
633 switch (frontend_state) {
634 case XenbusStateInitialising:
635 set_backend_state(be, XenbusStateInitWait);
638 case XenbusStateInitialised:
641 case XenbusStateConnected:
642 set_backend_state(be, XenbusStateConnected);
645 case XenbusStateClosing:
646 set_backend_state(be, XenbusStateClosing);
649 case XenbusStateClosed:
650 set_backend_state(be, XenbusStateClosed);
651 if (xenbus_dev_is_online(dev))
653 /* fall through if not online */
654 case XenbusStateUnknown:
655 set_backend_state(be, XenbusStateClosed);
656 device_unregister(&dev->dev);
660 xenbus_dev_fatal(dev, -EINVAL, "saw state %d at frontend",
667 static void xen_net_read_rate(struct xenbus_device *dev,
668 unsigned long *bytes, unsigned long *usec)
674 /* Default to unlimited bandwidth. */
678 ratestr = xenbus_read(XBT_NIL, dev->nodename, "rate", NULL);
683 b = simple_strtoul(s, &e, 10);
684 if ((s == e) || (*e != ','))
688 u = simple_strtoul(s, &e, 10);
689 if ((s == e) || (*e != '\0'))
699 pr_warn("Failed to parse network rate limit. Traffic unlimited.\n");
703 static int xen_net_read_mac(struct xenbus_device *dev, u8 mac[])
705 char *s, *e, *macstr;
708 macstr = s = xenbus_read(XBT_NIL, dev->nodename, "mac", NULL);
710 return PTR_ERR(macstr);
712 for (i = 0; i < ETH_ALEN; i++) {
713 mac[i] = simple_strtoul(s, &e, 16);
714 if ((s == e) || (*e != ((i == ETH_ALEN-1) ? '\0' : ':'))) {
725 static void xen_net_rate_changed(struct xenbus_watch *watch,
726 const char **vec, unsigned int len)
728 struct xenvif *vif = container_of(watch, struct xenvif, credit_watch);
729 struct xenbus_device *dev = xenvif_to_xenbus_device(vif);
730 unsigned long credit_bytes;
731 unsigned long credit_usec;
732 unsigned int queue_index;
734 xen_net_read_rate(dev, &credit_bytes, &credit_usec);
735 for (queue_index = 0; queue_index < vif->num_queues; queue_index++) {
736 struct xenvif_queue *queue = &vif->queues[queue_index];
738 queue->credit_bytes = credit_bytes;
739 queue->credit_usec = credit_usec;
740 if (!mod_timer_pending(&queue->credit_timeout, jiffies) &&
741 queue->remaining_credit > queue->credit_bytes) {
742 queue->remaining_credit = queue->credit_bytes;
747 static int xen_register_credit_watch(struct xenbus_device *dev,
752 unsigned maxlen = strlen(dev->nodename) + sizeof("/rate");
754 if (vif->credit_watch.node)
757 node = kmalloc(maxlen, GFP_KERNEL);
760 snprintf(node, maxlen, "%s/rate", dev->nodename);
761 vif->credit_watch.node = node;
762 vif->credit_watch.callback = xen_net_rate_changed;
763 err = register_xenbus_watch(&vif->credit_watch);
765 pr_err("Failed to set watcher %s\n", vif->credit_watch.node);
767 vif->credit_watch.node = NULL;
768 vif->credit_watch.callback = NULL;
773 static void xen_unregister_credit_watch(struct xenvif *vif)
775 if (vif->credit_watch.node) {
776 unregister_xenbus_watch(&vif->credit_watch);
777 kfree(vif->credit_watch.node);
778 vif->credit_watch.node = NULL;
782 static void xen_mcast_ctrl_changed(struct xenbus_watch *watch,
783 const char **vec, unsigned int len)
785 struct xenvif *vif = container_of(watch, struct xenvif,
787 struct xenbus_device *dev = xenvif_to_xenbus_device(vif);
789 vif->multicast_control = !!xenbus_read_unsigned(dev->otherend,
790 "request-multicast-control", 0);
793 static int xen_register_mcast_ctrl_watch(struct xenbus_device *dev,
798 unsigned maxlen = strlen(dev->otherend) +
799 sizeof("/request-multicast-control");
801 if (vif->mcast_ctrl_watch.node) {
802 pr_err_ratelimited("Watch is already registered\n");
806 node = kmalloc(maxlen, GFP_KERNEL);
808 pr_err("Failed to allocate memory for watch\n");
811 snprintf(node, maxlen, "%s/request-multicast-control",
813 vif->mcast_ctrl_watch.node = node;
814 vif->mcast_ctrl_watch.callback = xen_mcast_ctrl_changed;
815 err = register_xenbus_watch(&vif->mcast_ctrl_watch);
817 pr_err("Failed to set watcher %s\n",
818 vif->mcast_ctrl_watch.node);
820 vif->mcast_ctrl_watch.node = NULL;
821 vif->mcast_ctrl_watch.callback = NULL;
826 static void xen_unregister_mcast_ctrl_watch(struct xenvif *vif)
828 if (vif->mcast_ctrl_watch.node) {
829 unregister_xenbus_watch(&vif->mcast_ctrl_watch);
830 kfree(vif->mcast_ctrl_watch.node);
831 vif->mcast_ctrl_watch.node = NULL;
835 static void xen_register_watchers(struct xenbus_device *dev,
838 xen_register_credit_watch(dev, vif);
839 xen_register_mcast_ctrl_watch(dev, vif);
842 static void xen_unregister_watchers(struct xenvif *vif)
844 xen_unregister_mcast_ctrl_watch(vif);
845 xen_unregister_credit_watch(vif);
848 static void unregister_hotplug_status_watch(struct backend_info *be)
850 if (be->have_hotplug_status_watch) {
851 unregister_xenbus_watch(&be->hotplug_status_watch);
852 kfree(be->hotplug_status_watch.node);
854 be->have_hotplug_status_watch = 0;
857 static void hotplug_status_changed(struct xenbus_watch *watch,
859 unsigned int vec_size)
861 struct backend_info *be = container_of(watch,
863 hotplug_status_watch);
867 str = xenbus_read(XBT_NIL, be->dev->nodename, "hotplug-status", &len);
870 if (len == sizeof("connected")-1 && !memcmp(str, "connected", len)) {
871 /* Complete any pending state change */
872 xenbus_switch_state(be->dev, be->state);
874 /* Not interested in this watch anymore. */
875 unregister_hotplug_status_watch(be);
880 static int connect_ctrl_ring(struct backend_info *be)
882 struct xenbus_device *dev = be->dev;
883 struct xenvif *vif = be->vif;
885 grant_ref_t ring_ref;
889 err = xenbus_gather(XBT_NIL, dev->otherend,
890 "ctrl-ring-ref", "%u", &val, NULL);
892 goto done; /* The frontend does not have a control ring */
896 err = xenbus_gather(XBT_NIL, dev->otherend,
897 "event-channel-ctrl", "%u", &val, NULL);
899 xenbus_dev_fatal(dev, err,
900 "reading %s/event-channel-ctrl",
907 err = xenvif_connect_ctrl(vif, ring_ref, evtchn);
909 xenbus_dev_fatal(dev, err,
910 "mapping shared-frame %u port %u",
922 static void connect(struct backend_info *be)
925 struct xenbus_device *dev = be->dev;
926 unsigned long credit_bytes, credit_usec;
927 unsigned int queue_index;
928 unsigned int requested_num_queues;
929 struct xenvif_queue *queue;
931 /* Check whether the frontend requested multiple queues
932 * and read the number requested.
934 requested_num_queues = xenbus_read_unsigned(dev->otherend,
935 "multi-queue-num-queues", 1);
936 if (requested_num_queues > xenvif_max_queues) {
937 /* buggy or malicious guest */
938 xenbus_dev_fatal(dev, err,
939 "guest requested %u queues, exceeding the maximum of %u.",
940 requested_num_queues, xenvif_max_queues);
944 err = xen_net_read_mac(dev, be->vif->fe_dev_addr);
946 xenbus_dev_fatal(dev, err, "parsing %s/mac", dev->nodename);
950 xen_net_read_rate(dev, &credit_bytes, &credit_usec);
951 xen_unregister_watchers(be->vif);
952 xen_register_watchers(dev, be->vif);
953 read_xenbus_vif_flags(be);
955 err = connect_ctrl_ring(be);
957 xenbus_dev_fatal(dev, err, "connecting control ring");
961 /* Use the number of queues requested by the frontend */
962 be->vif->queues = vzalloc(requested_num_queues *
963 sizeof(struct xenvif_queue));
964 if (!be->vif->queues) {
965 xenbus_dev_fatal(dev, -ENOMEM,
966 "allocating queues");
970 be->vif->num_queues = requested_num_queues;
971 be->vif->stalled_queues = requested_num_queues;
973 for (queue_index = 0; queue_index < requested_num_queues; ++queue_index) {
974 queue = &be->vif->queues[queue_index];
975 queue->vif = be->vif;
976 queue->id = queue_index;
977 snprintf(queue->name, sizeof(queue->name), "%s-q%u",
978 be->vif->dev->name, queue->id);
980 err = xenvif_init_queue(queue);
982 /* xenvif_init_queue() cleans up after itself on
983 * failure, but we need to clean up any previously
984 * initialised queues. Set num_queues to i so that
985 * earlier queues can be destroyed using the regular
988 be->vif->num_queues = queue_index;
992 queue->credit_bytes = credit_bytes;
993 queue->remaining_credit = credit_bytes;
994 queue->credit_usec = credit_usec;
996 err = connect_data_rings(be, queue);
998 /* connect_data_rings() cleans up after itself on
999 * failure, but we need to clean up after
1000 * xenvif_init_queue() here, and also clean up any
1001 * previously initialised queues.
1003 xenvif_deinit_queue(queue);
1004 be->vif->num_queues = queue_index;
1009 #ifdef CONFIG_DEBUG_FS
1010 xenvif_debugfs_addif(be->vif);
1011 #endif /* CONFIG_DEBUG_FS */
1013 /* Initialisation completed, tell core driver the number of
1017 netif_set_real_num_tx_queues(be->vif->dev, requested_num_queues);
1018 netif_set_real_num_rx_queues(be->vif->dev, requested_num_queues);
1021 xenvif_carrier_on(be->vif);
1023 unregister_hotplug_status_watch(be);
1024 err = xenbus_watch_pathfmt(dev, &be->hotplug_status_watch,
1025 hotplug_status_changed,
1026 "%s/%s", dev->nodename, "hotplug-status");
1028 be->have_hotplug_status_watch = 1;
1030 netif_tx_wake_all_queues(be->vif->dev);
1035 if (be->vif->num_queues > 0)
1036 xenvif_disconnect_data(be->vif); /* Clean up existing queues */
1037 vfree(be->vif->queues);
1038 be->vif->queues = NULL;
1039 be->vif->num_queues = 0;
1040 xenvif_disconnect_ctrl(be->vif);
1045 static int connect_data_rings(struct backend_info *be,
1046 struct xenvif_queue *queue)
1048 struct xenbus_device *dev = be->dev;
1049 unsigned int num_queues = queue->vif->num_queues;
1050 unsigned long tx_ring_ref, rx_ring_ref;
1051 unsigned int tx_evtchn, rx_evtchn;
1055 const size_t xenstore_path_ext_size = 11; /* sufficient for "/queue-NNN" */
1057 /* If the frontend requested 1 queue, or we have fallen back
1058 * to single queue due to lack of frontend support for multi-
1059 * queue, expect the remaining XenStore keys in the toplevel
1060 * directory. Otherwise, expect them in a subdirectory called
1063 if (num_queues == 1) {
1064 xspath = kzalloc(strlen(dev->otherend) + 1, GFP_KERNEL);
1066 xenbus_dev_fatal(dev, -ENOMEM,
1067 "reading ring references");
1070 strcpy(xspath, dev->otherend);
1072 xspathsize = strlen(dev->otherend) + xenstore_path_ext_size;
1073 xspath = kzalloc(xspathsize, GFP_KERNEL);
1075 xenbus_dev_fatal(dev, -ENOMEM,
1076 "reading ring references");
1079 snprintf(xspath, xspathsize, "%s/queue-%u", dev->otherend,
1083 err = xenbus_gather(XBT_NIL, xspath,
1084 "tx-ring-ref", "%lu", &tx_ring_ref,
1085 "rx-ring-ref", "%lu", &rx_ring_ref, NULL);
1087 xenbus_dev_fatal(dev, err,
1088 "reading %s/ring-ref",
1093 /* Try split event channels first, then single event channel. */
1094 err = xenbus_gather(XBT_NIL, xspath,
1095 "event-channel-tx", "%u", &tx_evtchn,
1096 "event-channel-rx", "%u", &rx_evtchn, NULL);
1098 err = xenbus_scanf(XBT_NIL, xspath,
1099 "event-channel", "%u", &tx_evtchn);
1101 xenbus_dev_fatal(dev, err,
1102 "reading %s/event-channel(-tx/rx)",
1106 rx_evtchn = tx_evtchn;
1109 /* Map the shared frame, irq etc. */
1110 err = xenvif_connect_data(queue, tx_ring_ref, rx_ring_ref,
1111 tx_evtchn, rx_evtchn);
1113 xenbus_dev_fatal(dev, err,
1114 "mapping shared-frames %lu/%lu port tx %u rx %u",
1115 tx_ring_ref, rx_ring_ref,
1116 tx_evtchn, rx_evtchn);
1121 err: /* Regular return falls through with err == 0 */
1126 static int read_xenbus_vif_flags(struct backend_info *be)
1128 struct xenvif *vif = be->vif;
1129 struct xenbus_device *dev = be->dev;
1130 unsigned int rx_copy;
1133 err = xenbus_scanf(XBT_NIL, dev->otherend, "request-rx-copy", "%u",
1135 if (err == -ENOENT) {
1140 xenbus_dev_fatal(dev, err, "reading %s/request-rx-copy",
1147 if (!xenbus_read_unsigned(dev->otherend, "feature-rx-notify", 0)) {
1148 /* - Reduce drain timeout to poll more frequently for
1150 * - Disable Rx stall detection.
1152 be->vif->drain_timeout = msecs_to_jiffies(30);
1153 be->vif->stall_timeout = 0;
1156 vif->can_sg = !!xenbus_read_unsigned(dev->otherend, "feature-sg", 0);
1160 if (xenbus_read_unsigned(dev->otherend, "feature-gso-tcpv4", 0))
1161 vif->gso_mask |= GSO_BIT(TCPV4);
1163 if (xenbus_read_unsigned(dev->otherend, "feature-gso-tcpv6", 0))
1164 vif->gso_mask |= GSO_BIT(TCPV6);
1166 vif->ip_csum = !xenbus_read_unsigned(dev->otherend,
1167 "feature-no-csum-offload", 0);
1169 vif->ipv6_csum = !!xenbus_read_unsigned(dev->otherend,
1170 "feature-ipv6-csum-offload", 0);
1175 static const struct xenbus_device_id netback_ids[] = {
1180 static struct xenbus_driver netback_driver = {
1182 .probe = netback_probe,
1183 .remove = netback_remove,
1184 .uevent = netback_uevent,
1185 .otherend_changed = frontend_changed,
1188 int xenvif_xenbus_init(void)
1190 return xenbus_register_backend(&netback_driver);
1193 void xenvif_xenbus_fini(void)
1195 return xenbus_unregister_driver(&netback_driver);