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",
236 if (vif
->ctrl_task
) {
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
);
310 err
= xenbus_transaction_start(&xbt
);
312 xenbus_dev_fatal(dev
, err
, "starting transaction");
316 err
= xenbus_printf(xbt
, dev
->nodename
, "feature-sg", "%d", sg
);
318 message
= "writing feature-sg";
319 goto abort_transaction
;
322 err
= xenbus_printf(xbt
, dev
->nodename
, "feature-gso-tcpv4",
325 message
= "writing feature-gso-tcpv4";
326 goto abort_transaction
;
329 err
= xenbus_printf(xbt
, dev
->nodename
, "feature-gso-tcpv6",
332 message
= "writing feature-gso-tcpv6";
333 goto abort_transaction
;
336 /* We support partial checksum setup for IPv6 packets */
337 err
= xenbus_printf(xbt
, dev
->nodename
,
338 "feature-ipv6-csum-offload",
341 message
= "writing feature-ipv6-csum-offload";
342 goto abort_transaction
;
345 /* We support rx-copy path. */
346 err
= xenbus_printf(xbt
, dev
->nodename
,
347 "feature-rx-copy", "%d", 1);
349 message
= "writing feature-rx-copy";
350 goto abort_transaction
;
354 * We don't support rx-flip path (except old guests who don't
355 * grok this feature flag).
357 err
= xenbus_printf(xbt
, dev
->nodename
,
358 "feature-rx-flip", "%d", 0);
360 message
= "writing feature-rx-flip";
361 goto abort_transaction
;
364 /* We support dynamic multicast-control. */
365 err
= xenbus_printf(xbt
, dev
->nodename
,
366 "feature-multicast-control", "%d", 1);
368 message
= "writing feature-multicast-control";
369 goto abort_transaction
;
372 err
= xenbus_printf(xbt
, dev
->nodename
,
373 "feature-dynamic-multicast-control",
376 message
= "writing feature-dynamic-multicast-control";
377 goto abort_transaction
;
380 err
= xenbus_transaction_end(xbt
, 0);
381 } while (err
== -EAGAIN
);
384 xenbus_dev_fatal(dev
, err
, "completing transaction");
389 * Split event channels support, this is optional so it is not
390 * put inside the above loop.
392 err
= xenbus_printf(XBT_NIL
, dev
->nodename
,
393 "feature-split-event-channels",
394 "%u", separate_tx_rx_irq
);
396 pr_debug("Error writing feature-split-event-channels\n");
398 /* Multi-queue support: This is an optional feature. */
399 err
= xenbus_printf(XBT_NIL
, dev
->nodename
,
400 "multi-queue-max-queues", "%u", xenvif_max_queues
);
402 pr_debug("Error writing multi-queue-max-queues\n");
404 err
= xenbus_printf(XBT_NIL
, dev
->nodename
,
408 pr_debug("Error writing feature-ctrl-ring\n");
410 script
= xenbus_read(XBT_NIL
, dev
->nodename
, "script", NULL
);
411 if (IS_ERR(script
)) {
412 err
= PTR_ERR(script
);
413 xenbus_dev_fatal(dev
, err
, "reading script");
417 be
->hotplug_script
= script
;
419 err
= xenbus_switch_state(dev
, XenbusStateInitWait
);
423 be
->state
= XenbusStateInitWait
;
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 InitWait and the following transitions are
531 * 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 XenbusStateClosed
:
553 case XenbusStateInitWait
:
554 case XenbusStateConnected
:
555 backend_switch_state(be
, XenbusStateInitWait
);
557 case XenbusStateClosing
:
558 backend_switch_state(be
, XenbusStateClosing
);
564 case XenbusStateInitWait
:
566 case XenbusStateConnected
:
568 backend_switch_state(be
, XenbusStateConnected
);
570 case XenbusStateClosing
:
571 case XenbusStateClosed
:
572 backend_switch_state(be
, XenbusStateClosing
);
578 case XenbusStateConnected
:
580 case XenbusStateInitWait
:
581 case XenbusStateClosing
:
582 case XenbusStateClosed
:
583 backend_disconnect(be
);
584 backend_switch_state(be
, XenbusStateClosing
);
590 case XenbusStateClosing
:
592 case XenbusStateInitWait
:
593 case XenbusStateConnected
:
594 case XenbusStateClosed
:
595 backend_switch_state(be
, XenbusStateClosed
);
608 * Callback received when the frontend's state changes.
610 static void frontend_changed(struct xenbus_device
*dev
,
611 enum xenbus_state frontend_state
)
613 struct backend_info
*be
= dev_get_drvdata(&dev
->dev
);
615 pr_debug("%s -> %s\n", dev
->otherend
, xenbus_strstate(frontend_state
));
617 be
->frontend_state
= frontend_state
;
619 switch (frontend_state
) {
620 case XenbusStateInitialising
:
621 set_backend_state(be
, XenbusStateInitWait
);
624 case XenbusStateInitialised
:
627 case XenbusStateConnected
:
628 set_backend_state(be
, XenbusStateConnected
);
631 case XenbusStateClosing
:
632 set_backend_state(be
, XenbusStateClosing
);
635 case XenbusStateClosed
:
636 set_backend_state(be
, XenbusStateClosed
);
637 if (xenbus_dev_is_online(dev
))
639 /* fall through if not online */
640 case XenbusStateUnknown
:
641 set_backend_state(be
, XenbusStateClosed
);
642 device_unregister(&dev
->dev
);
646 xenbus_dev_fatal(dev
, -EINVAL
, "saw state %d at frontend",
653 static void xen_net_read_rate(struct xenbus_device
*dev
,
654 unsigned long *bytes
, unsigned long *usec
)
660 /* Default to unlimited bandwidth. */
664 ratestr
= xenbus_read(XBT_NIL
, dev
->nodename
, "rate", NULL
);
669 b
= simple_strtoul(s
, &e
, 10);
670 if ((s
== e
) || (*e
!= ','))
674 u
= simple_strtoul(s
, &e
, 10);
675 if ((s
== e
) || (*e
!= '\0'))
685 pr_warn("Failed to parse network rate limit. Traffic unlimited.\n");
689 static int xen_net_read_mac(struct xenbus_device
*dev
, u8 mac
[])
691 char *s
, *e
, *macstr
;
694 macstr
= s
= xenbus_read(XBT_NIL
, dev
->nodename
, "mac", NULL
);
696 return PTR_ERR(macstr
);
698 for (i
= 0; i
< ETH_ALEN
; i
++) {
699 mac
[i
] = simple_strtoul(s
, &e
, 16);
700 if ((s
== e
) || (*e
!= ((i
== ETH_ALEN
-1) ? '\0' : ':'))) {
711 static void xen_net_rate_changed(struct xenbus_watch
*watch
,
712 const char **vec
, unsigned int len
)
714 struct xenvif
*vif
= container_of(watch
, struct xenvif
, credit_watch
);
715 struct xenbus_device
*dev
= xenvif_to_xenbus_device(vif
);
716 unsigned long credit_bytes
;
717 unsigned long credit_usec
;
718 unsigned int queue_index
;
720 xen_net_read_rate(dev
, &credit_bytes
, &credit_usec
);
721 for (queue_index
= 0; queue_index
< vif
->num_queues
; queue_index
++) {
722 struct xenvif_queue
*queue
= &vif
->queues
[queue_index
];
724 queue
->credit_bytes
= credit_bytes
;
725 queue
->credit_usec
= credit_usec
;
726 if (!mod_timer_pending(&queue
->credit_timeout
, jiffies
) &&
727 queue
->remaining_credit
> queue
->credit_bytes
) {
728 queue
->remaining_credit
= queue
->credit_bytes
;
733 static int xen_register_credit_watch(struct xenbus_device
*dev
,
738 unsigned maxlen
= strlen(dev
->nodename
) + sizeof("/rate");
740 if (vif
->credit_watch
.node
)
743 node
= kmalloc(maxlen
, GFP_KERNEL
);
746 snprintf(node
, maxlen
, "%s/rate", dev
->nodename
);
747 vif
->credit_watch
.node
= node
;
748 vif
->credit_watch
.callback
= xen_net_rate_changed
;
749 err
= register_xenbus_watch(&vif
->credit_watch
);
751 pr_err("Failed to set watcher %s\n", vif
->credit_watch
.node
);
753 vif
->credit_watch
.node
= NULL
;
754 vif
->credit_watch
.callback
= NULL
;
759 static void xen_unregister_credit_watch(struct xenvif
*vif
)
761 if (vif
->credit_watch
.node
) {
762 unregister_xenbus_watch(&vif
->credit_watch
);
763 kfree(vif
->credit_watch
.node
);
764 vif
->credit_watch
.node
= NULL
;
768 static void xen_mcast_ctrl_changed(struct xenbus_watch
*watch
,
769 const char **vec
, unsigned int len
)
771 struct xenvif
*vif
= container_of(watch
, struct xenvif
,
773 struct xenbus_device
*dev
= xenvif_to_xenbus_device(vif
);
776 if (xenbus_scanf(XBT_NIL
, dev
->otherend
,
777 "request-multicast-control", "%d", &val
) < 0)
779 vif
->multicast_control
= !!val
;
782 static int xen_register_mcast_ctrl_watch(struct xenbus_device
*dev
,
787 unsigned maxlen
= strlen(dev
->otherend
) +
788 sizeof("/request-multicast-control");
790 if (vif
->mcast_ctrl_watch
.node
) {
791 pr_err_ratelimited("Watch is already registered\n");
795 node
= kmalloc(maxlen
, GFP_KERNEL
);
797 pr_err("Failed to allocate memory for watch\n");
800 snprintf(node
, maxlen
, "%s/request-multicast-control",
802 vif
->mcast_ctrl_watch
.node
= node
;
803 vif
->mcast_ctrl_watch
.callback
= xen_mcast_ctrl_changed
;
804 err
= register_xenbus_watch(&vif
->mcast_ctrl_watch
);
806 pr_err("Failed to set watcher %s\n",
807 vif
->mcast_ctrl_watch
.node
);
809 vif
->mcast_ctrl_watch
.node
= NULL
;
810 vif
->mcast_ctrl_watch
.callback
= NULL
;
815 static void xen_unregister_mcast_ctrl_watch(struct xenvif
*vif
)
817 if (vif
->mcast_ctrl_watch
.node
) {
818 unregister_xenbus_watch(&vif
->mcast_ctrl_watch
);
819 kfree(vif
->mcast_ctrl_watch
.node
);
820 vif
->mcast_ctrl_watch
.node
= NULL
;
824 static void xen_register_watchers(struct xenbus_device
*dev
,
827 xen_register_credit_watch(dev
, vif
);
828 xen_register_mcast_ctrl_watch(dev
, vif
);
831 static void xen_unregister_watchers(struct xenvif
*vif
)
833 xen_unregister_mcast_ctrl_watch(vif
);
834 xen_unregister_credit_watch(vif
);
837 static void unregister_hotplug_status_watch(struct backend_info
*be
)
839 if (be
->have_hotplug_status_watch
) {
840 unregister_xenbus_watch(&be
->hotplug_status_watch
);
841 kfree(be
->hotplug_status_watch
.node
);
843 be
->have_hotplug_status_watch
= 0;
846 static void hotplug_status_changed(struct xenbus_watch
*watch
,
848 unsigned int vec_size
)
850 struct backend_info
*be
= container_of(watch
,
852 hotplug_status_watch
);
856 str
= xenbus_read(XBT_NIL
, be
->dev
->nodename
, "hotplug-status", &len
);
859 if (len
== sizeof("connected")-1 && !memcmp(str
, "connected", len
)) {
860 /* Complete any pending state change */
861 xenbus_switch_state(be
->dev
, be
->state
);
863 /* Not interested in this watch anymore. */
864 unregister_hotplug_status_watch(be
);
869 static int connect_ctrl_ring(struct backend_info
*be
)
871 struct xenbus_device
*dev
= be
->dev
;
872 struct xenvif
*vif
= be
->vif
;
874 grant_ref_t ring_ref
;
878 err
= xenbus_gather(XBT_NIL
, dev
->otherend
,
879 "ctrl-ring-ref", "%u", &val
, NULL
);
881 goto done
; /* The frontend does not have a control ring */
885 err
= xenbus_gather(XBT_NIL
, dev
->otherend
,
886 "event-channel-ctrl", "%u", &val
, NULL
);
888 xenbus_dev_fatal(dev
, err
,
889 "reading %s/event-channel-ctrl",
896 err
= xenvif_connect_ctrl(vif
, ring_ref
, evtchn
);
898 xenbus_dev_fatal(dev
, err
,
899 "mapping shared-frame %u port %u",
911 static void connect(struct backend_info
*be
)
914 struct xenbus_device
*dev
= be
->dev
;
915 unsigned long credit_bytes
, credit_usec
;
916 unsigned int queue_index
;
917 unsigned int requested_num_queues
;
918 struct xenvif_queue
*queue
;
920 /* Check whether the frontend requested multiple queues
921 * and read the number requested.
923 err
= xenbus_scanf(XBT_NIL
, dev
->otherend
,
924 "multi-queue-num-queues",
925 "%u", &requested_num_queues
);
927 requested_num_queues
= 1; /* Fall back to single queue */
928 } else if (requested_num_queues
> xenvif_max_queues
) {
929 /* buggy or malicious guest */
930 xenbus_dev_fatal(dev
, err
,
931 "guest requested %u queues, exceeding the maximum of %u.",
932 requested_num_queues
, xenvif_max_queues
);
936 err
= xen_net_read_mac(dev
, be
->vif
->fe_dev_addr
);
938 xenbus_dev_fatal(dev
, err
, "parsing %s/mac", dev
->nodename
);
942 xen_net_read_rate(dev
, &credit_bytes
, &credit_usec
);
943 xen_unregister_watchers(be
->vif
);
944 xen_register_watchers(dev
, be
->vif
);
945 read_xenbus_vif_flags(be
);
947 err
= connect_ctrl_ring(be
);
949 xenbus_dev_fatal(dev
, err
, "connecting control ring");
953 /* Use the number of queues requested by the frontend */
954 be
->vif
->queues
= vzalloc(requested_num_queues
*
955 sizeof(struct xenvif_queue
));
956 if (!be
->vif
->queues
) {
957 xenbus_dev_fatal(dev
, -ENOMEM
,
958 "allocating queues");
962 be
->vif
->num_queues
= requested_num_queues
;
963 be
->vif
->stalled_queues
= requested_num_queues
;
965 for (queue_index
= 0; queue_index
< requested_num_queues
; ++queue_index
) {
966 queue
= &be
->vif
->queues
[queue_index
];
967 queue
->vif
= be
->vif
;
968 queue
->id
= queue_index
;
969 snprintf(queue
->name
, sizeof(queue
->name
), "%s-q%u",
970 be
->vif
->dev
->name
, queue
->id
);
972 err
= xenvif_init_queue(queue
);
974 /* xenvif_init_queue() cleans up after itself on
975 * failure, but we need to clean up any previously
976 * initialised queues. Set num_queues to i so that
977 * earlier queues can be destroyed using the regular
980 be
->vif
->num_queues
= queue_index
;
984 queue
->credit_bytes
= credit_bytes
;
985 queue
->remaining_credit
= credit_bytes
;
986 queue
->credit_usec
= credit_usec
;
988 err
= connect_data_rings(be
, queue
);
990 /* connect_data_rings() cleans up after itself on
991 * failure, but we need to clean up after
992 * xenvif_init_queue() here, and also clean up any
993 * previously initialised queues.
995 xenvif_deinit_queue(queue
);
996 be
->vif
->num_queues
= queue_index
;
1001 #ifdef CONFIG_DEBUG_FS
1002 xenvif_debugfs_addif(be
->vif
);
1003 #endif /* CONFIG_DEBUG_FS */
1005 /* Initialisation completed, tell core driver the number of
1009 netif_set_real_num_tx_queues(be
->vif
->dev
, requested_num_queues
);
1010 netif_set_real_num_rx_queues(be
->vif
->dev
, requested_num_queues
);
1013 xenvif_carrier_on(be
->vif
);
1015 unregister_hotplug_status_watch(be
);
1016 err
= xenbus_watch_pathfmt(dev
, &be
->hotplug_status_watch
,
1017 hotplug_status_changed
,
1018 "%s/%s", dev
->nodename
, "hotplug-status");
1020 be
->have_hotplug_status_watch
= 1;
1022 netif_tx_wake_all_queues(be
->vif
->dev
);
1027 if (be
->vif
->num_queues
> 0)
1028 xenvif_disconnect_data(be
->vif
); /* Clean up existing queues */
1029 vfree(be
->vif
->queues
);
1030 be
->vif
->queues
= NULL
;
1031 be
->vif
->num_queues
= 0;
1032 xenvif_disconnect_ctrl(be
->vif
);
1037 static int connect_data_rings(struct backend_info
*be
,
1038 struct xenvif_queue
*queue
)
1040 struct xenbus_device
*dev
= be
->dev
;
1041 unsigned int num_queues
= queue
->vif
->num_queues
;
1042 unsigned long tx_ring_ref
, rx_ring_ref
;
1043 unsigned int tx_evtchn
, rx_evtchn
;
1047 const size_t xenstore_path_ext_size
= 11; /* sufficient for "/queue-NNN" */
1049 /* If the frontend requested 1 queue, or we have fallen back
1050 * to single queue due to lack of frontend support for multi-
1051 * queue, expect the remaining XenStore keys in the toplevel
1052 * directory. Otherwise, expect them in a subdirectory called
1055 if (num_queues
== 1) {
1056 xspath
= kzalloc(strlen(dev
->otherend
) + 1, GFP_KERNEL
);
1058 xenbus_dev_fatal(dev
, -ENOMEM
,
1059 "reading ring references");
1062 strcpy(xspath
, dev
->otherend
);
1064 xspathsize
= strlen(dev
->otherend
) + xenstore_path_ext_size
;
1065 xspath
= kzalloc(xspathsize
, GFP_KERNEL
);
1067 xenbus_dev_fatal(dev
, -ENOMEM
,
1068 "reading ring references");
1071 snprintf(xspath
, xspathsize
, "%s/queue-%u", dev
->otherend
,
1075 err
= xenbus_gather(XBT_NIL
, xspath
,
1076 "tx-ring-ref", "%lu", &tx_ring_ref
,
1077 "rx-ring-ref", "%lu", &rx_ring_ref
, NULL
);
1079 xenbus_dev_fatal(dev
, err
,
1080 "reading %s/ring-ref",
1085 /* Try split event channels first, then single event channel. */
1086 err
= xenbus_gather(XBT_NIL
, xspath
,
1087 "event-channel-tx", "%u", &tx_evtchn
,
1088 "event-channel-rx", "%u", &rx_evtchn
, NULL
);
1090 err
= xenbus_scanf(XBT_NIL
, xspath
,
1091 "event-channel", "%u", &tx_evtchn
);
1093 xenbus_dev_fatal(dev
, err
,
1094 "reading %s/event-channel(-tx/rx)",
1098 rx_evtchn
= tx_evtchn
;
1101 /* Map the shared frame, irq etc. */
1102 err
= xenvif_connect_data(queue
, tx_ring_ref
, rx_ring_ref
,
1103 tx_evtchn
, rx_evtchn
);
1105 xenbus_dev_fatal(dev
, err
,
1106 "mapping shared-frames %lu/%lu port tx %u rx %u",
1107 tx_ring_ref
, rx_ring_ref
,
1108 tx_evtchn
, rx_evtchn
);
1113 err
: /* Regular return falls through with err == 0 */
1118 static int read_xenbus_vif_flags(struct backend_info
*be
)
1120 struct xenvif
*vif
= be
->vif
;
1121 struct xenbus_device
*dev
= be
->dev
;
1122 unsigned int rx_copy
;
1125 err
= xenbus_scanf(XBT_NIL
, dev
->otherend
, "request-rx-copy", "%u",
1127 if (err
== -ENOENT
) {
1132 xenbus_dev_fatal(dev
, err
, "reading %s/request-rx-copy",
1139 if (xenbus_scanf(XBT_NIL
, dev
->otherend
,
1140 "feature-rx-notify", "%d", &val
) < 0)
1143 /* - Reduce drain timeout to poll more frequently for
1145 * - Disable Rx stall detection.
1147 be
->vif
->drain_timeout
= msecs_to_jiffies(30);
1148 be
->vif
->stall_timeout
= 0;
1151 if (xenbus_scanf(XBT_NIL
, dev
->otherend
, "feature-sg",
1154 vif
->can_sg
= !!val
;
1157 vif
->gso_prefix_mask
= 0;
1159 if (xenbus_scanf(XBT_NIL
, dev
->otherend
, "feature-gso-tcpv4",
1163 vif
->gso_mask
|= GSO_BIT(TCPV4
);
1165 if (xenbus_scanf(XBT_NIL
, dev
->otherend
, "feature-gso-tcpv4-prefix",
1169 vif
->gso_prefix_mask
|= GSO_BIT(TCPV4
);
1171 if (xenbus_scanf(XBT_NIL
, dev
->otherend
, "feature-gso-tcpv6",
1175 vif
->gso_mask
|= GSO_BIT(TCPV6
);
1177 if (xenbus_scanf(XBT_NIL
, dev
->otherend
, "feature-gso-tcpv6-prefix",
1181 vif
->gso_prefix_mask
|= GSO_BIT(TCPV6
);
1183 if (vif
->gso_mask
& vif
->gso_prefix_mask
) {
1184 xenbus_dev_fatal(dev
, err
,
1185 "%s: gso and gso prefix flags are not "
1186 "mutually exclusive",
1191 if (xenbus_scanf(XBT_NIL
, dev
->otherend
, "feature-no-csum-offload",
1194 vif
->ip_csum
= !val
;
1196 if (xenbus_scanf(XBT_NIL
, dev
->otherend
, "feature-ipv6-csum-offload",
1199 vif
->ipv6_csum
= !!val
;
1204 static const struct xenbus_device_id netback_ids
[] = {
1209 static struct xenbus_driver netback_driver
= {
1211 .probe
= netback_probe
,
1212 .remove
= netback_remove
,
1213 .uevent
= netback_uevent
,
1214 .otherend_changed
= frontend_changed
,
1217 int xenvif_xenbus_init(void)
1219 return xenbus_register_backend(&netback_driver
);
1222 void xenvif_xenbus_fini(void)
1224 return xenbus_unregister_driver(&netback_driver
);