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
);
277 err
= xenbus_transaction_start(&xbt
);
279 xenbus_dev_fatal(dev
, err
, "starting transaction");
283 err
= xenbus_printf(xbt
, dev
->nodename
, "feature-sg", "%d", sg
);
285 message
= "writing feature-sg";
286 goto abort_transaction
;
289 err
= xenbus_printf(xbt
, dev
->nodename
, "feature-gso-tcpv4",
292 message
= "writing feature-gso-tcpv4";
293 goto abort_transaction
;
296 err
= xenbus_printf(xbt
, dev
->nodename
, "feature-gso-tcpv6",
299 message
= "writing feature-gso-tcpv6";
300 goto abort_transaction
;
303 /* We support partial checksum setup for IPv6 packets */
304 err
= xenbus_printf(xbt
, dev
->nodename
,
305 "feature-ipv6-csum-offload",
308 message
= "writing feature-ipv6-csum-offload";
309 goto abort_transaction
;
312 /* We support rx-copy path. */
313 err
= xenbus_printf(xbt
, dev
->nodename
,
314 "feature-rx-copy", "%d", 1);
316 message
= "writing feature-rx-copy";
317 goto abort_transaction
;
321 * We don't support rx-flip path (except old guests who don't
322 * grok this feature flag).
324 err
= xenbus_printf(xbt
, dev
->nodename
,
325 "feature-rx-flip", "%d", 0);
327 message
= "writing feature-rx-flip";
328 goto abort_transaction
;
331 /* We support dynamic multicast-control. */
332 err
= xenbus_printf(xbt
, dev
->nodename
,
333 "feature-multicast-control", "%d", 1);
335 message
= "writing feature-multicast-control";
336 goto abort_transaction
;
339 err
= xenbus_printf(xbt
, dev
->nodename
,
340 "feature-dynamic-multicast-control",
343 message
= "writing feature-dynamic-multicast-control";
344 goto abort_transaction
;
347 err
= xenbus_transaction_end(xbt
, 0);
348 } while (err
== -EAGAIN
);
351 xenbus_dev_fatal(dev
, err
, "completing transaction");
356 * Split event channels support, this is optional so it is not
357 * put inside the above loop.
359 err
= xenbus_printf(XBT_NIL
, dev
->nodename
,
360 "feature-split-event-channels",
361 "%u", separate_tx_rx_irq
);
363 pr_debug("Error writing feature-split-event-channels\n");
365 /* Multi-queue support: This is an optional feature. */
366 err
= xenbus_printf(XBT_NIL
, dev
->nodename
,
367 "multi-queue-max-queues", "%u", xenvif_max_queues
);
369 pr_debug("Error writing multi-queue-max-queues\n");
371 err
= xenbus_printf(XBT_NIL
, dev
->nodename
,
375 pr_debug("Error writing feature-ctrl-ring\n");
377 script
= xenbus_read(XBT_NIL
, dev
->nodename
, "script", NULL
);
378 if (IS_ERR(script
)) {
379 err
= PTR_ERR(script
);
380 xenbus_dev_fatal(dev
, err
, "reading script");
384 be
->hotplug_script
= script
;
386 err
= xenbus_switch_state(dev
, XenbusStateInitWait
);
390 be
->state
= XenbusStateInitWait
;
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 InitWait and the following transitions are
498 * 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 XenbusStateClosed
:
520 case XenbusStateInitWait
:
521 case XenbusStateConnected
:
522 backend_switch_state(be
, XenbusStateInitWait
);
524 case XenbusStateClosing
:
525 backend_switch_state(be
, XenbusStateClosing
);
531 case XenbusStateInitWait
:
533 case XenbusStateConnected
:
535 backend_switch_state(be
, XenbusStateConnected
);
537 case XenbusStateClosing
:
538 case XenbusStateClosed
:
539 backend_switch_state(be
, XenbusStateClosing
);
545 case XenbusStateConnected
:
547 case XenbusStateInitWait
:
548 case XenbusStateClosing
:
549 case XenbusStateClosed
:
550 backend_disconnect(be
);
551 backend_switch_state(be
, XenbusStateClosing
);
557 case XenbusStateClosing
:
559 case XenbusStateInitWait
:
560 case XenbusStateConnected
:
561 case XenbusStateClosed
:
562 backend_switch_state(be
, XenbusStateClosed
);
575 * Callback received when the frontend's state changes.
577 static void frontend_changed(struct xenbus_device
*dev
,
578 enum xenbus_state frontend_state
)
580 struct backend_info
*be
= dev_get_drvdata(&dev
->dev
);
582 pr_debug("%s -> %s\n", dev
->otherend
, xenbus_strstate(frontend_state
));
584 be
->frontend_state
= frontend_state
;
586 switch (frontend_state
) {
587 case XenbusStateInitialising
:
588 set_backend_state(be
, XenbusStateInitWait
);
591 case XenbusStateInitialised
:
594 case XenbusStateConnected
:
595 set_backend_state(be
, XenbusStateConnected
);
598 case XenbusStateClosing
:
599 set_backend_state(be
, XenbusStateClosing
);
602 case XenbusStateClosed
:
603 set_backend_state(be
, XenbusStateClosed
);
604 if (xenbus_dev_is_online(dev
))
606 /* fall through if not online */
607 case XenbusStateUnknown
:
608 set_backend_state(be
, XenbusStateClosed
);
609 device_unregister(&dev
->dev
);
613 xenbus_dev_fatal(dev
, -EINVAL
, "saw state %d at frontend",
620 static void xen_net_read_rate(struct xenbus_device
*dev
,
621 unsigned long *bytes
, unsigned long *usec
)
627 /* Default to unlimited bandwidth. */
631 ratestr
= xenbus_read(XBT_NIL
, dev
->nodename
, "rate", NULL
);
636 b
= simple_strtoul(s
, &e
, 10);
637 if ((s
== e
) || (*e
!= ','))
641 u
= simple_strtoul(s
, &e
, 10);
642 if ((s
== e
) || (*e
!= '\0'))
652 pr_warn("Failed to parse network rate limit. Traffic unlimited.\n");
656 static int xen_net_read_mac(struct xenbus_device
*dev
, u8 mac
[])
658 char *s
, *e
, *macstr
;
661 macstr
= s
= xenbus_read(XBT_NIL
, dev
->nodename
, "mac", NULL
);
663 return PTR_ERR(macstr
);
665 for (i
= 0; i
< ETH_ALEN
; i
++) {
666 mac
[i
] = simple_strtoul(s
, &e
, 16);
667 if ((s
== e
) || (*e
!= ((i
== ETH_ALEN
-1) ? '\0' : ':'))) {
678 static void xen_net_rate_changed(struct xenbus_watch
*watch
,
679 const char **vec
, unsigned int len
)
681 struct xenvif
*vif
= container_of(watch
, struct xenvif
, credit_watch
);
682 struct xenbus_device
*dev
= xenvif_to_xenbus_device(vif
);
683 unsigned long credit_bytes
;
684 unsigned long credit_usec
;
685 unsigned int queue_index
;
687 xen_net_read_rate(dev
, &credit_bytes
, &credit_usec
);
688 for (queue_index
= 0; queue_index
< vif
->num_queues
; queue_index
++) {
689 struct xenvif_queue
*queue
= &vif
->queues
[queue_index
];
691 queue
->credit_bytes
= credit_bytes
;
692 queue
->credit_usec
= credit_usec
;
693 if (!mod_timer_pending(&queue
->credit_timeout
, jiffies
) &&
694 queue
->remaining_credit
> queue
->credit_bytes
) {
695 queue
->remaining_credit
= queue
->credit_bytes
;
700 static int xen_register_credit_watch(struct xenbus_device
*dev
,
705 unsigned maxlen
= strlen(dev
->nodename
) + sizeof("/rate");
707 if (vif
->credit_watch
.node
)
710 node
= kmalloc(maxlen
, GFP_KERNEL
);
713 snprintf(node
, maxlen
, "%s/rate", dev
->nodename
);
714 vif
->credit_watch
.node
= node
;
715 vif
->credit_watch
.callback
= xen_net_rate_changed
;
716 err
= register_xenbus_watch(&vif
->credit_watch
);
718 pr_err("Failed to set watcher %s\n", vif
->credit_watch
.node
);
720 vif
->credit_watch
.node
= NULL
;
721 vif
->credit_watch
.callback
= NULL
;
726 static void xen_unregister_credit_watch(struct xenvif
*vif
)
728 if (vif
->credit_watch
.node
) {
729 unregister_xenbus_watch(&vif
->credit_watch
);
730 kfree(vif
->credit_watch
.node
);
731 vif
->credit_watch
.node
= NULL
;
735 static void xen_mcast_ctrl_changed(struct xenbus_watch
*watch
,
736 const char **vec
, unsigned int len
)
738 struct xenvif
*vif
= container_of(watch
, struct xenvif
,
740 struct xenbus_device
*dev
= xenvif_to_xenbus_device(vif
);
743 if (xenbus_scanf(XBT_NIL
, dev
->otherend
,
744 "request-multicast-control", "%d", &val
) < 0)
746 vif
->multicast_control
= !!val
;
749 static int xen_register_mcast_ctrl_watch(struct xenbus_device
*dev
,
754 unsigned maxlen
= strlen(dev
->otherend
) +
755 sizeof("/request-multicast-control");
757 if (vif
->mcast_ctrl_watch
.node
) {
758 pr_err_ratelimited("Watch is already registered\n");
762 node
= kmalloc(maxlen
, GFP_KERNEL
);
764 pr_err("Failed to allocate memory for watch\n");
767 snprintf(node
, maxlen
, "%s/request-multicast-control",
769 vif
->mcast_ctrl_watch
.node
= node
;
770 vif
->mcast_ctrl_watch
.callback
= xen_mcast_ctrl_changed
;
771 err
= register_xenbus_watch(&vif
->mcast_ctrl_watch
);
773 pr_err("Failed to set watcher %s\n",
774 vif
->mcast_ctrl_watch
.node
);
776 vif
->mcast_ctrl_watch
.node
= NULL
;
777 vif
->mcast_ctrl_watch
.callback
= NULL
;
782 static void xen_unregister_mcast_ctrl_watch(struct xenvif
*vif
)
784 if (vif
->mcast_ctrl_watch
.node
) {
785 unregister_xenbus_watch(&vif
->mcast_ctrl_watch
);
786 kfree(vif
->mcast_ctrl_watch
.node
);
787 vif
->mcast_ctrl_watch
.node
= NULL
;
791 static void xen_register_watchers(struct xenbus_device
*dev
,
794 xen_register_credit_watch(dev
, vif
);
795 xen_register_mcast_ctrl_watch(dev
, vif
);
798 static void xen_unregister_watchers(struct xenvif
*vif
)
800 xen_unregister_mcast_ctrl_watch(vif
);
801 xen_unregister_credit_watch(vif
);
804 static void unregister_hotplug_status_watch(struct backend_info
*be
)
806 if (be
->have_hotplug_status_watch
) {
807 unregister_xenbus_watch(&be
->hotplug_status_watch
);
808 kfree(be
->hotplug_status_watch
.node
);
810 be
->have_hotplug_status_watch
= 0;
813 static void hotplug_status_changed(struct xenbus_watch
*watch
,
815 unsigned int vec_size
)
817 struct backend_info
*be
= container_of(watch
,
819 hotplug_status_watch
);
823 str
= xenbus_read(XBT_NIL
, be
->dev
->nodename
, "hotplug-status", &len
);
826 if (len
== sizeof("connected")-1 && !memcmp(str
, "connected", len
)) {
827 /* Complete any pending state change */
828 xenbus_switch_state(be
->dev
, be
->state
);
830 /* Not interested in this watch anymore. */
831 unregister_hotplug_status_watch(be
);
836 static int connect_ctrl_ring(struct backend_info
*be
)
838 struct xenbus_device
*dev
= be
->dev
;
839 struct xenvif
*vif
= be
->vif
;
841 grant_ref_t ring_ref
;
845 err
= xenbus_gather(XBT_NIL
, dev
->otherend
,
846 "ctrl-ring-ref", "%u", &val
, NULL
);
848 goto done
; /* The frontend does not have a control ring */
852 err
= xenbus_gather(XBT_NIL
, dev
->otherend
,
853 "event-channel-ctrl", "%u", &val
, NULL
);
855 xenbus_dev_fatal(dev
, err
,
856 "reading %s/event-channel-ctrl",
863 err
= xenvif_connect_ctrl(vif
, ring_ref
, evtchn
);
865 xenbus_dev_fatal(dev
, err
,
866 "mapping shared-frame %u port %u",
878 static void connect(struct backend_info
*be
)
881 struct xenbus_device
*dev
= be
->dev
;
882 unsigned long credit_bytes
, credit_usec
;
883 unsigned int queue_index
;
884 unsigned int requested_num_queues
;
885 struct xenvif_queue
*queue
;
887 /* Check whether the frontend requested multiple queues
888 * and read the number requested.
890 err
= xenbus_scanf(XBT_NIL
, dev
->otherend
,
891 "multi-queue-num-queues",
892 "%u", &requested_num_queues
);
894 requested_num_queues
= 1; /* Fall back to single queue */
895 } else if (requested_num_queues
> xenvif_max_queues
) {
896 /* buggy or malicious guest */
897 xenbus_dev_fatal(dev
, err
,
898 "guest requested %u queues, exceeding the maximum of %u.",
899 requested_num_queues
, xenvif_max_queues
);
903 err
= xen_net_read_mac(dev
, be
->vif
->fe_dev_addr
);
905 xenbus_dev_fatal(dev
, err
, "parsing %s/mac", dev
->nodename
);
909 xen_net_read_rate(dev
, &credit_bytes
, &credit_usec
);
910 xen_unregister_watchers(be
->vif
);
911 xen_register_watchers(dev
, be
->vif
);
912 read_xenbus_vif_flags(be
);
914 err
= connect_ctrl_ring(be
);
916 xenbus_dev_fatal(dev
, err
, "connecting control ring");
920 /* Use the number of queues requested by the frontend */
921 be
->vif
->queues
= vzalloc(requested_num_queues
*
922 sizeof(struct xenvif_queue
));
923 if (!be
->vif
->queues
) {
924 xenbus_dev_fatal(dev
, -ENOMEM
,
925 "allocating queues");
929 be
->vif
->num_queues
= requested_num_queues
;
930 be
->vif
->stalled_queues
= requested_num_queues
;
932 for (queue_index
= 0; queue_index
< requested_num_queues
; ++queue_index
) {
933 queue
= &be
->vif
->queues
[queue_index
];
934 queue
->vif
= be
->vif
;
935 queue
->id
= queue_index
;
936 snprintf(queue
->name
, sizeof(queue
->name
), "%s-q%u",
937 be
->vif
->dev
->name
, queue
->id
);
939 err
= xenvif_init_queue(queue
);
941 /* xenvif_init_queue() cleans up after itself on
942 * failure, but we need to clean up any previously
943 * initialised queues. Set num_queues to i so that
944 * earlier queues can be destroyed using the regular
947 be
->vif
->num_queues
= queue_index
;
951 queue
->credit_bytes
= credit_bytes
;
952 queue
->remaining_credit
= credit_bytes
;
953 queue
->credit_usec
= credit_usec
;
955 err
= connect_data_rings(be
, queue
);
957 /* connect_data_rings() cleans up after itself on
958 * failure, but we need to clean up after
959 * xenvif_init_queue() here, and also clean up any
960 * previously initialised queues.
962 xenvif_deinit_queue(queue
);
963 be
->vif
->num_queues
= queue_index
;
968 #ifdef CONFIG_DEBUG_FS
969 xenvif_debugfs_addif(be
->vif
);
970 #endif /* CONFIG_DEBUG_FS */
972 /* Initialisation completed, tell core driver the number of
976 netif_set_real_num_tx_queues(be
->vif
->dev
, requested_num_queues
);
977 netif_set_real_num_rx_queues(be
->vif
->dev
, requested_num_queues
);
980 xenvif_carrier_on(be
->vif
);
982 unregister_hotplug_status_watch(be
);
983 err
= xenbus_watch_pathfmt(dev
, &be
->hotplug_status_watch
,
984 hotplug_status_changed
,
985 "%s/%s", dev
->nodename
, "hotplug-status");
987 be
->have_hotplug_status_watch
= 1;
989 netif_tx_wake_all_queues(be
->vif
->dev
);
994 if (be
->vif
->num_queues
> 0)
995 xenvif_disconnect_data(be
->vif
); /* Clean up existing queues */
996 vfree(be
->vif
->queues
);
997 be
->vif
->queues
= NULL
;
998 be
->vif
->num_queues
= 0;
999 xenvif_disconnect_ctrl(be
->vif
);
1004 static int connect_data_rings(struct backend_info
*be
,
1005 struct xenvif_queue
*queue
)
1007 struct xenbus_device
*dev
= be
->dev
;
1008 unsigned int num_queues
= queue
->vif
->num_queues
;
1009 unsigned long tx_ring_ref
, rx_ring_ref
;
1010 unsigned int tx_evtchn
, rx_evtchn
;
1014 const size_t xenstore_path_ext_size
= 11; /* sufficient for "/queue-NNN" */
1016 /* If the frontend requested 1 queue, or we have fallen back
1017 * to single queue due to lack of frontend support for multi-
1018 * queue, expect the remaining XenStore keys in the toplevel
1019 * directory. Otherwise, expect them in a subdirectory called
1022 if (num_queues
== 1) {
1023 xspath
= kzalloc(strlen(dev
->otherend
) + 1, GFP_KERNEL
);
1025 xenbus_dev_fatal(dev
, -ENOMEM
,
1026 "reading ring references");
1029 strcpy(xspath
, dev
->otherend
);
1031 xspathsize
= strlen(dev
->otherend
) + xenstore_path_ext_size
;
1032 xspath
= kzalloc(xspathsize
, GFP_KERNEL
);
1034 xenbus_dev_fatal(dev
, -ENOMEM
,
1035 "reading ring references");
1038 snprintf(xspath
, xspathsize
, "%s/queue-%u", dev
->otherend
,
1042 err
= xenbus_gather(XBT_NIL
, xspath
,
1043 "tx-ring-ref", "%lu", &tx_ring_ref
,
1044 "rx-ring-ref", "%lu", &rx_ring_ref
, NULL
);
1046 xenbus_dev_fatal(dev
, err
,
1047 "reading %s/ring-ref",
1052 /* Try split event channels first, then single event channel. */
1053 err
= xenbus_gather(XBT_NIL
, xspath
,
1054 "event-channel-tx", "%u", &tx_evtchn
,
1055 "event-channel-rx", "%u", &rx_evtchn
, NULL
);
1057 err
= xenbus_scanf(XBT_NIL
, xspath
,
1058 "event-channel", "%u", &tx_evtchn
);
1060 xenbus_dev_fatal(dev
, err
,
1061 "reading %s/event-channel(-tx/rx)",
1065 rx_evtchn
= tx_evtchn
;
1068 /* Map the shared frame, irq etc. */
1069 err
= xenvif_connect_data(queue
, tx_ring_ref
, rx_ring_ref
,
1070 tx_evtchn
, rx_evtchn
);
1072 xenbus_dev_fatal(dev
, err
,
1073 "mapping shared-frames %lu/%lu port tx %u rx %u",
1074 tx_ring_ref
, rx_ring_ref
,
1075 tx_evtchn
, rx_evtchn
);
1080 err
: /* Regular return falls through with err == 0 */
1085 static int read_xenbus_vif_flags(struct backend_info
*be
)
1087 struct xenvif
*vif
= be
->vif
;
1088 struct xenbus_device
*dev
= be
->dev
;
1089 unsigned int rx_copy
;
1092 err
= xenbus_scanf(XBT_NIL
, dev
->otherend
, "request-rx-copy", "%u",
1094 if (err
== -ENOENT
) {
1099 xenbus_dev_fatal(dev
, err
, "reading %s/request-rx-copy",
1106 if (xenbus_scanf(XBT_NIL
, dev
->otherend
,
1107 "feature-rx-notify", "%d", &val
) < 0)
1110 /* - Reduce drain timeout to poll more frequently for
1112 * - Disable Rx stall detection.
1114 be
->vif
->drain_timeout
= msecs_to_jiffies(30);
1115 be
->vif
->stall_timeout
= 0;
1118 if (xenbus_scanf(XBT_NIL
, dev
->otherend
, "feature-sg",
1121 vif
->can_sg
= !!val
;
1124 vif
->gso_prefix_mask
= 0;
1126 if (xenbus_scanf(XBT_NIL
, dev
->otherend
, "feature-gso-tcpv4",
1130 vif
->gso_mask
|= GSO_BIT(TCPV4
);
1132 if (xenbus_scanf(XBT_NIL
, dev
->otherend
, "feature-gso-tcpv4-prefix",
1136 vif
->gso_prefix_mask
|= GSO_BIT(TCPV4
);
1138 if (xenbus_scanf(XBT_NIL
, dev
->otherend
, "feature-gso-tcpv6",
1142 vif
->gso_mask
|= GSO_BIT(TCPV6
);
1144 if (xenbus_scanf(XBT_NIL
, dev
->otherend
, "feature-gso-tcpv6-prefix",
1148 vif
->gso_prefix_mask
|= GSO_BIT(TCPV6
);
1150 if (vif
->gso_mask
& vif
->gso_prefix_mask
) {
1151 xenbus_dev_fatal(dev
, err
,
1152 "%s: gso and gso prefix flags are not "
1153 "mutually exclusive",
1158 if (xenbus_scanf(XBT_NIL
, dev
->otherend
, "feature-no-csum-offload",
1161 vif
->ip_csum
= !val
;
1163 if (xenbus_scanf(XBT_NIL
, dev
->otherend
, "feature-ipv6-csum-offload",
1166 vif
->ipv6_csum
= !!val
;
1171 static const struct xenbus_device_id netback_ids
[] = {
1176 static struct xenbus_driver netback_driver
= {
1178 .probe
= netback_probe
,
1179 .remove
= netback_remove
,
1180 .uevent
= netback_uevent
,
1181 .otherend_changed
= frontend_changed
,
1184 int xenvif_xenbus_init(void)
1186 return xenbus_register_backend(&netback_driver
);
1189 void xenvif_xenbus_fini(void)
1191 return xenbus_unregister_driver(&netback_driver
);