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;
39 static int connect_rings(struct backend_info
*be
, struct xenvif_queue
*queue
);
40 static void connect(struct backend_info
*be
);
41 static int read_xenbus_vif_flags(struct backend_info
*be
);
42 static int backend_create_xenvif(struct backend_info
*be
);
43 static void unregister_hotplug_status_watch(struct backend_info
*be
);
44 static void set_backend_state(struct backend_info
*be
,
45 enum xenbus_state state
);
47 #ifdef CONFIG_DEBUG_FS
48 struct dentry
*xen_netback_dbg_root
= NULL
;
50 static int xenvif_read_io_ring(struct seq_file
*m
, void *v
)
52 struct xenvif_queue
*queue
= m
->private;
53 struct xen_netif_tx_back_ring
*tx_ring
= &queue
->tx
;
54 struct xen_netif_rx_back_ring
*rx_ring
= &queue
->rx
;
55 struct netdev_queue
*dev_queue
;
58 struct xen_netif_tx_sring
*sring
= tx_ring
->sring
;
60 seq_printf(m
, "Queue %d\nTX: nr_ents %u\n", queue
->id
,
62 seq_printf(m
, "req prod %u (%d) cons %u (%d) event %u (%d)\n",
64 sring
->req_prod
- sring
->rsp_prod
,
66 tx_ring
->req_cons
- sring
->rsp_prod
,
68 sring
->req_event
- sring
->rsp_prod
);
69 seq_printf(m
, "rsp prod %u (base) pvt %u (%d) event %u (%d)\n",
71 tx_ring
->rsp_prod_pvt
,
72 tx_ring
->rsp_prod_pvt
- sring
->rsp_prod
,
74 sring
->rsp_event
- sring
->rsp_prod
);
75 seq_printf(m
, "pending prod %u pending cons %u nr_pending_reqs %u\n",
78 nr_pending_reqs(queue
));
79 seq_printf(m
, "dealloc prod %u dealloc cons %u dealloc_queue %u\n\n",
82 queue
->dealloc_prod
- queue
->dealloc_cons
);
86 struct xen_netif_rx_sring
*sring
= rx_ring
->sring
;
88 seq_printf(m
, "RX: nr_ents %u\n", rx_ring
->nr_ents
);
89 seq_printf(m
, "req prod %u (%d) cons %u (%d) event %u (%d)\n",
91 sring
->req_prod
- sring
->rsp_prod
,
93 rx_ring
->req_cons
- sring
->rsp_prod
,
95 sring
->req_event
- sring
->rsp_prod
);
96 seq_printf(m
, "rsp prod %u (base) pvt %u (%d) event %u (%d)\n\n",
98 rx_ring
->rsp_prod_pvt
,
99 rx_ring
->rsp_prod_pvt
- sring
->rsp_prod
,
101 sring
->rsp_event
- sring
->rsp_prod
);
104 seq_printf(m
, "NAPI state: %lx NAPI weight: %d TX queue len %u\n"
105 "Credit timer_pending: %d, credit: %lu, usec: %lu\n"
106 "remaining: %lu, expires: %lu, now: %lu\n",
107 queue
->napi
.state
, queue
->napi
.weight
,
108 skb_queue_len(&queue
->tx_queue
),
109 timer_pending(&queue
->credit_timeout
),
112 queue
->remaining_credit
,
113 queue
->credit_timeout
.expires
,
116 dev_queue
= netdev_get_tx_queue(queue
->vif
->dev
, queue
->id
);
118 seq_printf(m
, "\nRx internal queue: len %u max %u pkts %u %s\n",
119 queue
->rx_queue_len
, queue
->rx_queue_max
,
120 skb_queue_len(&queue
->rx_queue
),
121 netif_tx_queue_stopped(dev_queue
) ? "stopped" : "running");
126 #define XENVIF_KICK_STR "kick"
127 #define BUFFER_SIZE 32
130 xenvif_write_io_ring(struct file
*filp
, const char __user
*buf
, size_t count
,
133 struct xenvif_queue
*queue
=
134 ((struct seq_file
*)filp
->private_data
)->private;
136 char write
[BUFFER_SIZE
];
138 /* don't allow partial writes and check the length */
141 if (count
>= sizeof(write
))
144 len
= simple_write_to_buffer(write
,
154 if (!strncmp(write
, XENVIF_KICK_STR
, sizeof(XENVIF_KICK_STR
) - 1))
155 xenvif_interrupt(0, (void *)queue
);
157 pr_warn("Unknown command to io_ring_q%d. Available: kick\n",
164 static int xenvif_dump_open(struct inode
*inode
, struct file
*filp
)
169 if (inode
->i_private
)
170 queue
= inode
->i_private
;
171 ret
= single_open(filp
, xenvif_read_io_ring
, queue
);
172 filp
->f_mode
|= FMODE_PWRITE
;
176 static const struct file_operations xenvif_dbg_io_ring_ops_fops
= {
177 .owner
= THIS_MODULE
,
178 .open
= xenvif_dump_open
,
181 .release
= single_release
,
182 .write
= xenvif_write_io_ring
,
185 static void xenvif_debugfs_addif(struct xenvif
*vif
)
187 struct dentry
*pfile
;
190 if (IS_ERR_OR_NULL(xen_netback_dbg_root
))
193 vif
->xenvif_dbg_root
= debugfs_create_dir(vif
->dev
->name
,
194 xen_netback_dbg_root
);
195 if (!IS_ERR_OR_NULL(vif
->xenvif_dbg_root
)) {
196 for (i
= 0; i
< vif
->num_queues
; ++i
) {
197 char filename
[sizeof("io_ring_q") + 4];
199 snprintf(filename
, sizeof(filename
), "io_ring_q%d", i
);
200 pfile
= debugfs_create_file(filename
,
202 vif
->xenvif_dbg_root
,
204 &xenvif_dbg_io_ring_ops_fops
);
205 if (IS_ERR_OR_NULL(pfile
))
206 pr_warn("Creation of io_ring file returned %ld!\n",
210 netdev_warn(vif
->dev
,
211 "Creation of vif debugfs dir returned %ld!\n",
212 PTR_ERR(vif
->xenvif_dbg_root
));
215 static void xenvif_debugfs_delif(struct xenvif
*vif
)
217 if (IS_ERR_OR_NULL(xen_netback_dbg_root
))
220 if (!IS_ERR_OR_NULL(vif
->xenvif_dbg_root
))
221 debugfs_remove_recursive(vif
->xenvif_dbg_root
);
222 vif
->xenvif_dbg_root
= NULL
;
224 #endif /* CONFIG_DEBUG_FS */
226 static int netback_remove(struct xenbus_device
*dev
)
228 struct backend_info
*be
= dev_get_drvdata(&dev
->dev
);
230 set_backend_state(be
, XenbusStateClosed
);
232 unregister_hotplug_status_watch(be
);
234 kobject_uevent(&dev
->dev
.kobj
, KOBJ_OFFLINE
);
235 xenbus_rm(XBT_NIL
, dev
->nodename
, "hotplug-status");
236 xenvif_free(be
->vif
);
240 dev_set_drvdata(&dev
->dev
, NULL
);
246 * Entry point to this code when a new device is created. Allocate the basic
247 * structures and switch to InitWait.
249 static int netback_probe(struct xenbus_device
*dev
,
250 const struct xenbus_device_id
*id
)
253 struct xenbus_transaction xbt
;
256 struct backend_info
*be
= kzalloc(sizeof(struct backend_info
),
259 xenbus_dev_fatal(dev
, -ENOMEM
,
260 "allocating backend structure");
265 dev_set_drvdata(&dev
->dev
, be
);
270 err
= xenbus_transaction_start(&xbt
);
272 xenbus_dev_fatal(dev
, err
, "starting transaction");
276 err
= xenbus_printf(xbt
, dev
->nodename
, "feature-sg", "%d", sg
);
278 message
= "writing feature-sg";
279 goto abort_transaction
;
282 err
= xenbus_printf(xbt
, dev
->nodename
, "feature-gso-tcpv4",
285 message
= "writing feature-gso-tcpv4";
286 goto abort_transaction
;
289 err
= xenbus_printf(xbt
, dev
->nodename
, "feature-gso-tcpv6",
292 message
= "writing feature-gso-tcpv6";
293 goto abort_transaction
;
296 /* We support partial checksum setup for IPv6 packets */
297 err
= xenbus_printf(xbt
, dev
->nodename
,
298 "feature-ipv6-csum-offload",
301 message
= "writing feature-ipv6-csum-offload";
302 goto abort_transaction
;
305 /* We support rx-copy path. */
306 err
= xenbus_printf(xbt
, dev
->nodename
,
307 "feature-rx-copy", "%d", 1);
309 message
= "writing feature-rx-copy";
310 goto abort_transaction
;
314 * We don't support rx-flip path (except old guests who don't
315 * grok this feature flag).
317 err
= xenbus_printf(xbt
, dev
->nodename
,
318 "feature-rx-flip", "%d", 0);
320 message
= "writing feature-rx-flip";
321 goto abort_transaction
;
324 err
= xenbus_transaction_end(xbt
, 0);
325 } while (err
== -EAGAIN
);
328 xenbus_dev_fatal(dev
, err
, "completing transaction");
333 * Split event channels support, this is optional so it is not
334 * put inside the above loop.
336 err
= xenbus_printf(XBT_NIL
, dev
->nodename
,
337 "feature-split-event-channels",
338 "%u", separate_tx_rx_irq
);
340 pr_debug("Error writing feature-split-event-channels\n");
342 /* Multi-queue support: This is an optional feature. */
343 err
= xenbus_printf(XBT_NIL
, dev
->nodename
,
344 "multi-queue-max-queues", "%u", xenvif_max_queues
);
346 pr_debug("Error writing multi-queue-max-queues\n");
348 err
= xenbus_switch_state(dev
, XenbusStateInitWait
);
352 be
->state
= XenbusStateInitWait
;
354 /* This kicks hotplug scripts, so do it immediately. */
355 err
= backend_create_xenvif(be
);
362 xenbus_transaction_end(xbt
, 1);
363 xenbus_dev_fatal(dev
, err
, "%s", message
);
365 pr_debug("failed\n");
372 * Handle the creation of the hotplug script environment. We add the script
373 * and vif variables to the environment, for the benefit of the vif-* hotplug
376 static int netback_uevent(struct xenbus_device
*xdev
,
377 struct kobj_uevent_env
*env
)
379 struct backend_info
*be
= dev_get_drvdata(&xdev
->dev
);
382 val
= xenbus_read(XBT_NIL
, xdev
->nodename
, "script", NULL
);
384 int err
= PTR_ERR(val
);
385 xenbus_dev_fatal(xdev
, err
, "reading script");
388 if (add_uevent_var(env
, "script=%s", val
)) {
398 return add_uevent_var(env
, "vif=%s", be
->vif
->dev
->name
);
402 static int backend_create_xenvif(struct backend_info
*be
)
406 struct xenbus_device
*dev
= be
->dev
;
411 err
= xenbus_scanf(XBT_NIL
, dev
->nodename
, "handle", "%li", &handle
);
413 xenbus_dev_fatal(dev
, err
, "reading handle");
414 return (err
< 0) ? err
: -EINVAL
;
417 be
->vif
= xenvif_alloc(&dev
->dev
, dev
->otherend_id
, handle
);
418 if (IS_ERR(be
->vif
)) {
419 err
= PTR_ERR(be
->vif
);
421 xenbus_dev_fatal(dev
, err
, "creating interface");
425 kobject_uevent(&dev
->dev
.kobj
, KOBJ_ONLINE
);
429 static void backend_disconnect(struct backend_info
*be
)
432 #ifdef CONFIG_DEBUG_FS
433 xenvif_debugfs_delif(be
->vif
);
434 #endif /* CONFIG_DEBUG_FS */
435 xenvif_disconnect(be
->vif
);
439 static void backend_connect(struct backend_info
*be
)
445 static inline void backend_switch_state(struct backend_info
*be
,
446 enum xenbus_state state
)
448 struct xenbus_device
*dev
= be
->dev
;
450 pr_debug("%s -> %s\n", dev
->nodename
, xenbus_strstate(state
));
453 /* If we are waiting for a hotplug script then defer the
454 * actual xenbus state change.
456 if (!be
->have_hotplug_status_watch
)
457 xenbus_switch_state(dev
, state
);
460 /* Handle backend state transitions:
462 * The backend state starts in InitWait and the following transitions are
465 * InitWait -> Connected
477 * The state argument specifies the eventual state of the backend and the
478 * function transitions to that state via the shortest path.
480 static void set_backend_state(struct backend_info
*be
,
481 enum xenbus_state state
)
483 while (be
->state
!= state
) {
485 case XenbusStateClosed
:
487 case XenbusStateInitWait
:
488 case XenbusStateConnected
:
489 pr_info("%s: prepare for reconnect\n",
491 backend_switch_state(be
, XenbusStateInitWait
);
493 case XenbusStateClosing
:
494 backend_switch_state(be
, XenbusStateClosing
);
500 case XenbusStateInitWait
:
502 case XenbusStateConnected
:
504 backend_switch_state(be
, XenbusStateConnected
);
506 case XenbusStateClosing
:
507 case XenbusStateClosed
:
508 backend_switch_state(be
, XenbusStateClosing
);
514 case XenbusStateConnected
:
516 case XenbusStateInitWait
:
517 case XenbusStateClosing
:
518 case XenbusStateClosed
:
519 backend_disconnect(be
);
520 backend_switch_state(be
, XenbusStateClosing
);
526 case XenbusStateClosing
:
528 case XenbusStateInitWait
:
529 case XenbusStateConnected
:
530 case XenbusStateClosed
:
531 backend_switch_state(be
, XenbusStateClosed
);
544 * Callback received when the frontend's state changes.
546 static void frontend_changed(struct xenbus_device
*dev
,
547 enum xenbus_state frontend_state
)
549 struct backend_info
*be
= dev_get_drvdata(&dev
->dev
);
551 pr_debug("%s -> %s\n", dev
->otherend
, xenbus_strstate(frontend_state
));
553 be
->frontend_state
= frontend_state
;
555 switch (frontend_state
) {
556 case XenbusStateInitialising
:
557 set_backend_state(be
, XenbusStateInitWait
);
560 case XenbusStateInitialised
:
563 case XenbusStateConnected
:
564 set_backend_state(be
, XenbusStateConnected
);
567 case XenbusStateClosing
:
568 set_backend_state(be
, XenbusStateClosing
);
571 case XenbusStateClosed
:
572 set_backend_state(be
, XenbusStateClosed
);
573 if (xenbus_dev_is_online(dev
))
575 /* fall through if not online */
576 case XenbusStateUnknown
:
577 set_backend_state(be
, XenbusStateClosed
);
578 device_unregister(&dev
->dev
);
582 xenbus_dev_fatal(dev
, -EINVAL
, "saw state %d at frontend",
589 static void xen_net_read_rate(struct xenbus_device
*dev
,
590 unsigned long *bytes
, unsigned long *usec
)
596 /* Default to unlimited bandwidth. */
600 ratestr
= xenbus_read(XBT_NIL
, dev
->nodename
, "rate", NULL
);
605 b
= simple_strtoul(s
, &e
, 10);
606 if ((s
== e
) || (*e
!= ','))
610 u
= simple_strtoul(s
, &e
, 10);
611 if ((s
== e
) || (*e
!= '\0'))
621 pr_warn("Failed to parse network rate limit. Traffic unlimited.\n");
625 static int xen_net_read_mac(struct xenbus_device
*dev
, u8 mac
[])
627 char *s
, *e
, *macstr
;
630 macstr
= s
= xenbus_read(XBT_NIL
, dev
->nodename
, "mac", NULL
);
632 return PTR_ERR(macstr
);
634 for (i
= 0; i
< ETH_ALEN
; i
++) {
635 mac
[i
] = simple_strtoul(s
, &e
, 16);
636 if ((s
== e
) || (*e
!= ((i
== ETH_ALEN
-1) ? '\0' : ':'))) {
647 static void unregister_hotplug_status_watch(struct backend_info
*be
)
649 if (be
->have_hotplug_status_watch
) {
650 unregister_xenbus_watch(&be
->hotplug_status_watch
);
651 kfree(be
->hotplug_status_watch
.node
);
653 be
->have_hotplug_status_watch
= 0;
656 static void hotplug_status_changed(struct xenbus_watch
*watch
,
658 unsigned int vec_size
)
660 struct backend_info
*be
= container_of(watch
,
662 hotplug_status_watch
);
666 str
= xenbus_read(XBT_NIL
, be
->dev
->nodename
, "hotplug-status", &len
);
669 if (len
== sizeof("connected")-1 && !memcmp(str
, "connected", len
)) {
670 /* Complete any pending state change */
671 xenbus_switch_state(be
->dev
, be
->state
);
673 /* Not interested in this watch anymore. */
674 unregister_hotplug_status_watch(be
);
679 static void connect(struct backend_info
*be
)
682 struct xenbus_device
*dev
= be
->dev
;
683 unsigned long credit_bytes
, credit_usec
;
684 unsigned int queue_index
;
685 unsigned int requested_num_queues
;
686 struct xenvif_queue
*queue
;
688 /* Check whether the frontend requested multiple queues
689 * and read the number requested.
691 err
= xenbus_scanf(XBT_NIL
, dev
->otherend
,
692 "multi-queue-num-queues",
693 "%u", &requested_num_queues
);
695 requested_num_queues
= 1; /* Fall back to single queue */
696 } else if (requested_num_queues
> xenvif_max_queues
) {
697 /* buggy or malicious guest */
698 xenbus_dev_fatal(dev
, err
,
699 "guest requested %u queues, exceeding the maximum of %u.",
700 requested_num_queues
, xenvif_max_queues
);
704 err
= xen_net_read_mac(dev
, be
->vif
->fe_dev_addr
);
706 xenbus_dev_fatal(dev
, err
, "parsing %s/mac", dev
->nodename
);
710 xen_net_read_rate(dev
, &credit_bytes
, &credit_usec
);
711 read_xenbus_vif_flags(be
);
713 /* Use the number of queues requested by the frontend */
714 be
->vif
->queues
= vzalloc(requested_num_queues
*
715 sizeof(struct xenvif_queue
));
716 be
->vif
->num_queues
= requested_num_queues
;
717 be
->vif
->stalled_queues
= requested_num_queues
;
719 for (queue_index
= 0; queue_index
< requested_num_queues
; ++queue_index
) {
720 queue
= &be
->vif
->queues
[queue_index
];
721 queue
->vif
= be
->vif
;
722 queue
->id
= queue_index
;
723 snprintf(queue
->name
, sizeof(queue
->name
), "%s-q%u",
724 be
->vif
->dev
->name
, queue
->id
);
726 err
= xenvif_init_queue(queue
);
728 /* xenvif_init_queue() cleans up after itself on
729 * failure, but we need to clean up any previously
730 * initialised queues. Set num_queues to i so that
731 * earlier queues can be destroyed using the regular
734 be
->vif
->num_queues
= queue_index
;
738 queue
->remaining_credit
= credit_bytes
;
740 err
= connect_rings(be
, queue
);
742 /* connect_rings() cleans up after itself on failure,
743 * but we need to clean up after xenvif_init_queue() here,
744 * and also clean up any previously initialised queues.
746 xenvif_deinit_queue(queue
);
747 be
->vif
->num_queues
= queue_index
;
752 #ifdef CONFIG_DEBUG_FS
753 xenvif_debugfs_addif(be
->vif
);
754 #endif /* CONFIG_DEBUG_FS */
756 /* Initialisation completed, tell core driver the number of
760 netif_set_real_num_tx_queues(be
->vif
->dev
, requested_num_queues
);
761 netif_set_real_num_rx_queues(be
->vif
->dev
, requested_num_queues
);
764 xenvif_carrier_on(be
->vif
);
766 unregister_hotplug_status_watch(be
);
767 err
= xenbus_watch_pathfmt(dev
, &be
->hotplug_status_watch
,
768 hotplug_status_changed
,
769 "%s/%s", dev
->nodename
, "hotplug-status");
771 be
->have_hotplug_status_watch
= 1;
773 netif_tx_wake_all_queues(be
->vif
->dev
);
778 if (be
->vif
->num_queues
> 0)
779 xenvif_disconnect(be
->vif
); /* Clean up existing queues */
780 vfree(be
->vif
->queues
);
781 be
->vif
->queues
= NULL
;
782 be
->vif
->num_queues
= 0;
787 static int connect_rings(struct backend_info
*be
, struct xenvif_queue
*queue
)
789 struct xenbus_device
*dev
= be
->dev
;
790 unsigned int num_queues
= queue
->vif
->num_queues
;
791 unsigned long tx_ring_ref
, rx_ring_ref
;
792 unsigned int tx_evtchn
, rx_evtchn
;
796 const size_t xenstore_path_ext_size
= 11; /* sufficient for "/queue-NNN" */
798 /* If the frontend requested 1 queue, or we have fallen back
799 * to single queue due to lack of frontend support for multi-
800 * queue, expect the remaining XenStore keys in the toplevel
801 * directory. Otherwise, expect them in a subdirectory called
804 if (num_queues
== 1) {
805 xspath
= kzalloc(strlen(dev
->otherend
) + 1, GFP_KERNEL
);
807 xenbus_dev_fatal(dev
, -ENOMEM
,
808 "reading ring references");
811 strcpy(xspath
, dev
->otherend
);
813 xspathsize
= strlen(dev
->otherend
) + xenstore_path_ext_size
;
814 xspath
= kzalloc(xspathsize
, GFP_KERNEL
);
816 xenbus_dev_fatal(dev
, -ENOMEM
,
817 "reading ring references");
820 snprintf(xspath
, xspathsize
, "%s/queue-%u", dev
->otherend
,
824 err
= xenbus_gather(XBT_NIL
, xspath
,
825 "tx-ring-ref", "%lu", &tx_ring_ref
,
826 "rx-ring-ref", "%lu", &rx_ring_ref
, NULL
);
828 xenbus_dev_fatal(dev
, err
,
829 "reading %s/ring-ref",
834 /* Try split event channels first, then single event channel. */
835 err
= xenbus_gather(XBT_NIL
, xspath
,
836 "event-channel-tx", "%u", &tx_evtchn
,
837 "event-channel-rx", "%u", &rx_evtchn
, NULL
);
839 err
= xenbus_scanf(XBT_NIL
, xspath
,
840 "event-channel", "%u", &tx_evtchn
);
842 xenbus_dev_fatal(dev
, err
,
843 "reading %s/event-channel(-tx/rx)",
847 rx_evtchn
= tx_evtchn
;
850 /* Map the shared frame, irq etc. */
851 err
= xenvif_connect(queue
, tx_ring_ref
, rx_ring_ref
,
852 tx_evtchn
, rx_evtchn
);
854 xenbus_dev_fatal(dev
, err
,
855 "mapping shared-frames %lu/%lu port tx %u rx %u",
856 tx_ring_ref
, rx_ring_ref
,
857 tx_evtchn
, rx_evtchn
);
862 err
: /* Regular return falls through with err == 0 */
867 static int read_xenbus_vif_flags(struct backend_info
*be
)
869 struct xenvif
*vif
= be
->vif
;
870 struct xenbus_device
*dev
= be
->dev
;
871 unsigned int rx_copy
;
874 err
= xenbus_scanf(XBT_NIL
, dev
->otherend
, "request-rx-copy", "%u",
876 if (err
== -ENOENT
) {
881 xenbus_dev_fatal(dev
, err
, "reading %s/request-rx-copy",
888 if (xenbus_scanf(XBT_NIL
, dev
->otherend
,
889 "feature-rx-notify", "%d", &val
) < 0 || val
== 0) {
890 xenbus_dev_fatal(dev
, -EINVAL
, "feature-rx-notify is mandatory");
894 if (xenbus_scanf(XBT_NIL
, dev
->otherend
, "feature-sg",
900 vif
->gso_prefix_mask
= 0;
902 if (xenbus_scanf(XBT_NIL
, dev
->otherend
, "feature-gso-tcpv4",
906 vif
->gso_mask
|= GSO_BIT(TCPV4
);
908 if (xenbus_scanf(XBT_NIL
, dev
->otherend
, "feature-gso-tcpv4-prefix",
912 vif
->gso_prefix_mask
|= GSO_BIT(TCPV4
);
914 if (xenbus_scanf(XBT_NIL
, dev
->otherend
, "feature-gso-tcpv6",
918 vif
->gso_mask
|= GSO_BIT(TCPV6
);
920 if (xenbus_scanf(XBT_NIL
, dev
->otherend
, "feature-gso-tcpv6-prefix",
924 vif
->gso_prefix_mask
|= GSO_BIT(TCPV6
);
926 if (vif
->gso_mask
& vif
->gso_prefix_mask
) {
927 xenbus_dev_fatal(dev
, err
,
928 "%s: gso and gso prefix flags are not "
929 "mutually exclusive",
934 if (xenbus_scanf(XBT_NIL
, dev
->otherend
, "feature-no-csum-offload",
939 if (xenbus_scanf(XBT_NIL
, dev
->otherend
, "feature-ipv6-csum-offload",
942 vif
->ipv6_csum
= !!val
;
947 static const struct xenbus_device_id netback_ids
[] = {
952 static struct xenbus_driver netback_driver
= {
954 .probe
= netback_probe
,
955 .remove
= netback_remove
,
956 .uevent
= netback_uevent
,
957 .otherend_changed
= frontend_changed
,
960 int xenvif_xenbus_init(void)
962 return xenbus_register_backend(&netback_driver
);
965 void xenvif_xenbus_fini(void)
967 return xenbus_unregister_driver(&netback_driver
);