2 * xen backend driver infrastructure
3 * (c) 2008 Gerd Hoffmann <kraxel@redhat.com>
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; under version 2 of the License.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public License along
15 * with this program; if not, see <http://www.gnu.org/licenses/>.
17 * Contributions after 2012-01-13 are licensed under the terms of the
18 * GNU GPL, version 2 or (at your option) any later version.
22 * TODO: add some xenbus / xenstore concepts overview here.
25 #include "qemu/osdep.h"
26 #include <sys/signal.h>
29 #include "hw/sysbus.h"
30 #include "hw/boards.h"
32 #include "qapi/error.h"
33 #include "hw/xen/xen_backend.h"
34 #include "hw/xen/xen_pvdev.h"
35 #include "monitor/qdev.h"
37 #include <xen/grant_table.h>
39 DeviceState
*xen_sysdev
;
42 /* ------------------------------------------------------------- */
45 struct xs_handle
*xenstore
= NULL
;
46 const char *xen_protocol
;
51 int xenstore_write_be_str(struct XenDevice
*xendev
, const char *node
, const char *val
)
53 return xenstore_write_str(xendev
->be
, node
, val
);
56 int xenstore_write_be_int(struct XenDevice
*xendev
, const char *node
, int ival
)
58 return xenstore_write_int(xendev
->be
, node
, ival
);
61 int xenstore_write_be_int64(struct XenDevice
*xendev
, const char *node
, int64_t ival
)
63 return xenstore_write_int64(xendev
->be
, node
, ival
);
66 char *xenstore_read_be_str(struct XenDevice
*xendev
, const char *node
)
68 return xenstore_read_str(xendev
->be
, node
);
71 int xenstore_read_be_int(struct XenDevice
*xendev
, const char *node
, int *ival
)
73 return xenstore_read_int(xendev
->be
, node
, ival
);
76 char *xenstore_read_fe_str(struct XenDevice
*xendev
, const char *node
)
78 return xenstore_read_str(xendev
->fe
, node
);
81 int xenstore_read_fe_int(struct XenDevice
*xendev
, const char *node
, int *ival
)
83 return xenstore_read_int(xendev
->fe
, node
, ival
);
86 int xenstore_read_fe_uint64(struct XenDevice
*xendev
, const char *node
,
89 return xenstore_read_uint64(xendev
->fe
, node
, uval
);
92 /* ------------------------------------------------------------- */
94 int xen_be_set_state(struct XenDevice
*xendev
, enum xenbus_state state
)
98 rc
= xenstore_write_be_int(xendev
, "state", state
);
102 xen_pv_printf(xendev
, 1, "backend state: %s -> %s\n",
103 xenbus_strstate(xendev
->be_state
), xenbus_strstate(state
));
104 xendev
->be_state
= state
;
109 * get xen backend device, allocate a new one if it doesn't exist.
111 static struct XenDevice
*xen_be_get_xendev(const char *type
, int dom
, int dev
,
112 struct XenDevOps
*ops
)
114 struct XenDevice
*xendev
;
116 xendev
= xen_pv_find_xendev(type
, dom
, dev
);
121 /* init new xendev */
122 xendev
= g_malloc0(ops
->size
);
123 object_initialize(&xendev
->qdev
, ops
->size
, TYPE_XENBACKEND
);
124 OBJECT(xendev
)->free
= g_free
;
125 qdev_set_parent_bus(DEVICE(xendev
), xen_sysbus
);
126 qdev_set_id(DEVICE(xendev
), g_strdup_printf("xen-%s-%d", type
, dev
));
127 qdev_init_nofail(DEVICE(xendev
));
128 object_unref(OBJECT(xendev
));
135 snprintf(xendev
->be
, sizeof(xendev
->be
), "backend/%s/%d/%d",
136 xendev
->type
, xendev
->dom
, xendev
->dev
);
137 snprintf(xendev
->name
, sizeof(xendev
->name
), "%s-%d",
138 xendev
->type
, xendev
->dev
);
140 xendev
->debug
= debug
;
141 xendev
->local_port
= -1;
143 xendev
->evtchndev
= xenevtchn_open(NULL
, 0);
144 if (xendev
->evtchndev
== NULL
) {
145 xen_pv_printf(NULL
, 0, "can't open evtchn device\n");
146 qdev_unplug(DEVICE(xendev
), NULL
);
149 qemu_set_cloexec(xenevtchn_fd(xendev
->evtchndev
));
151 if (ops
->flags
& DEVOPS_FLAG_NEED_GNTDEV
) {
152 xendev
->gnttabdev
= xengnttab_open(NULL
, 0);
153 if (xendev
->gnttabdev
== NULL
) {
154 xen_pv_printf(NULL
, 0, "can't open gnttab device\n");
155 xenevtchn_close(xendev
->evtchndev
);
156 qdev_unplug(DEVICE(xendev
), NULL
);
160 xendev
->gnttabdev
= NULL
;
163 xen_pv_insert_xendev(xendev
);
165 if (xendev
->ops
->alloc
) {
166 xendev
->ops
->alloc(xendev
);
174 * Sync internal data structures on xenstore updates.
175 * Node specifies the changed field. node = NULL means
176 * update all fields (used for initialization).
178 static void xen_be_backend_changed(struct XenDevice
*xendev
, const char *node
)
180 if (node
== NULL
|| strcmp(node
, "online") == 0) {
181 if (xenstore_read_be_int(xendev
, "online", &xendev
->online
) == -1) {
187 xen_pv_printf(xendev
, 2, "backend update: %s\n", node
);
188 if (xendev
->ops
->backend_changed
) {
189 xendev
->ops
->backend_changed(xendev
, node
);
194 static void xen_be_frontend_changed(struct XenDevice
*xendev
, const char *node
)
198 if (node
== NULL
|| strcmp(node
, "state") == 0) {
199 if (xenstore_read_fe_int(xendev
, "state", &fe_state
) == -1) {
200 fe_state
= XenbusStateUnknown
;
202 if (xendev
->fe_state
!= fe_state
) {
203 xen_pv_printf(xendev
, 1, "frontend state: %s -> %s\n",
204 xenbus_strstate(xendev
->fe_state
),
205 xenbus_strstate(fe_state
));
207 xendev
->fe_state
= fe_state
;
209 if (node
== NULL
|| strcmp(node
, "protocol") == 0) {
210 g_free(xendev
->protocol
);
211 xendev
->protocol
= xenstore_read_fe_str(xendev
, "protocol");
212 if (xendev
->protocol
) {
213 xen_pv_printf(xendev
, 1, "frontend protocol: %s\n",
219 xen_pv_printf(xendev
, 2, "frontend update: %s\n", node
);
220 if (xendev
->ops
->frontend_changed
) {
221 xendev
->ops
->frontend_changed(xendev
, node
);
226 /* ------------------------------------------------------------- */
227 /* Check for possible state transitions and perform them. */
230 * Initial xendev setup. Read frontend path, register watch for it.
231 * Should succeed once xend finished setting up the backend device.
233 * Also sets initial state (-> Initializing) when done. Which
234 * only affects the xendev->be_state variable as xenbus should
235 * already be put into that state by xend.
237 static int xen_be_try_setup(struct XenDevice
*xendev
)
239 char token
[XEN_BUFSIZE
];
242 if (xenstore_read_be_int(xendev
, "state", &be_state
) == -1) {
243 xen_pv_printf(xendev
, 0, "reading backend state failed\n");
247 if (be_state
!= XenbusStateInitialising
) {
248 xen_pv_printf(xendev
, 0, "initial backend state is wrong (%s)\n",
249 xenbus_strstate(be_state
));
253 xendev
->fe
= xenstore_read_be_str(xendev
, "frontend");
254 if (xendev
->fe
== NULL
) {
255 xen_pv_printf(xendev
, 0, "reading frontend path failed\n");
259 /* setup frontend watch */
260 snprintf(token
, sizeof(token
), "fe:%p", xendev
);
261 if (!xs_watch(xenstore
, xendev
->fe
, token
)) {
262 xen_pv_printf(xendev
, 0, "watching frontend path (%s) failed\n",
266 xen_be_set_state(xendev
, XenbusStateInitialising
);
268 xen_be_backend_changed(xendev
, NULL
);
269 xen_be_frontend_changed(xendev
, NULL
);
274 * Try initialize xendev. Prepare everything the backend can do
275 * without synchronizing with the frontend. Fakes hotplug-status. No
276 * hotplug involved here because this is about userspace drivers, thus
277 * there are kernel backend devices which could invoke hotplug.
279 * Goes to InitWait on success.
281 static int xen_be_try_init(struct XenDevice
*xendev
)
285 if (!xendev
->online
) {
286 xen_pv_printf(xendev
, 1, "not online\n");
290 if (xendev
->ops
->init
) {
291 rc
= xendev
->ops
->init(xendev
);
294 xen_pv_printf(xendev
, 1, "init() failed\n");
298 xenstore_write_be_str(xendev
, "hotplug-status", "connected");
299 xen_be_set_state(xendev
, XenbusStateInitWait
);
304 * Try to initialise xendev. Depends on the frontend being ready
305 * for it (shared ring and evtchn info in xenstore, state being
306 * Initialised or Connected).
308 * Goes to Connected on success.
310 static int xen_be_try_initialise(struct XenDevice
*xendev
)
314 if (xendev
->fe_state
!= XenbusStateInitialised
&&
315 xendev
->fe_state
!= XenbusStateConnected
) {
316 if (xendev
->ops
->flags
& DEVOPS_FLAG_IGNORE_STATE
) {
317 xen_pv_printf(xendev
, 2, "frontend not ready, ignoring\n");
319 xen_pv_printf(xendev
, 2, "frontend not ready (yet)\n");
324 if (xendev
->ops
->initialise
) {
325 rc
= xendev
->ops
->initialise(xendev
);
328 xen_pv_printf(xendev
, 0, "initialise() failed\n");
332 xen_be_set_state(xendev
, XenbusStateConnected
);
337 * Try to let xendev know that it is connected. Depends on the
338 * frontend being Connected. Note that this may be called more
339 * than once since the backend state is not modified.
341 static void xen_be_try_connected(struct XenDevice
*xendev
)
343 if (!xendev
->ops
->connected
) {
347 if (xendev
->fe_state
!= XenbusStateConnected
) {
348 if (xendev
->ops
->flags
& DEVOPS_FLAG_IGNORE_STATE
) {
349 xen_pv_printf(xendev
, 2, "frontend not ready, ignoring\n");
351 xen_pv_printf(xendev
, 2, "frontend not ready (yet)\n");
356 xendev
->ops
->connected(xendev
);
360 * Teardown connection.
362 * Goes to Closed when done.
364 static void xen_be_disconnect(struct XenDevice
*xendev
, enum xenbus_state state
)
366 if (xendev
->be_state
!= XenbusStateClosing
&&
367 xendev
->be_state
!= XenbusStateClosed
&&
368 xendev
->ops
->disconnect
) {
369 xendev
->ops
->disconnect(xendev
);
371 if (xendev
->be_state
!= state
) {
372 xen_be_set_state(xendev
, state
);
377 * Try to reset xendev, for reconnection by another frontend instance.
379 static int xen_be_try_reset(struct XenDevice
*xendev
)
381 if (xendev
->fe_state
!= XenbusStateInitialising
) {
385 xen_pv_printf(xendev
, 1, "device reset (for re-connect)\n");
386 xen_be_set_state(xendev
, XenbusStateInitialising
);
391 * state change dispatcher function
393 void xen_be_check_state(struct XenDevice
*xendev
)
397 /* frontend may request shutdown from almost anywhere */
398 if (xendev
->fe_state
== XenbusStateClosing
||
399 xendev
->fe_state
== XenbusStateClosed
) {
400 xen_be_disconnect(xendev
, xendev
->fe_state
);
404 /* check for possible backend state transitions */
406 switch (xendev
->be_state
) {
407 case XenbusStateUnknown
:
408 rc
= xen_be_try_setup(xendev
);
410 case XenbusStateInitialising
:
411 rc
= xen_be_try_init(xendev
);
413 case XenbusStateInitWait
:
414 rc
= xen_be_try_initialise(xendev
);
416 case XenbusStateConnected
:
417 /* xendev->be_state doesn't change */
418 xen_be_try_connected(xendev
);
421 case XenbusStateClosed
:
422 rc
= xen_be_try_reset(xendev
);
433 /* ------------------------------------------------------------- */
435 static int xenstore_scan(const char *type
, int dom
, struct XenDevOps
*ops
)
437 struct XenDevice
*xendev
;
438 char path
[XEN_BUFSIZE
], token
[XEN_BUFSIZE
];
440 unsigned int cdev
, j
;
443 snprintf(token
, sizeof(token
), "be:%p:%d:%p", type
, dom
, ops
);
444 snprintf(path
, sizeof(path
), "backend/%s/%d", type
, dom
);
445 if (!xs_watch(xenstore
, path
, token
)) {
446 xen_pv_printf(NULL
, 0, "xen be: watching backend path (%s) failed\n",
451 /* look for backends */
452 dev
= xs_directory(xenstore
, 0, path
, &cdev
);
456 for (j
= 0; j
< cdev
; j
++) {
457 xendev
= xen_be_get_xendev(type
, dom
, atoi(dev
[j
]), ops
);
458 if (xendev
== NULL
) {
461 xen_be_check_state(xendev
);
467 void xenstore_update_be(char *watch
, char *type
, int dom
,
468 struct XenDevOps
*ops
)
470 struct XenDevice
*xendev
;
471 char path
[XEN_BUFSIZE
], *bepath
;
472 unsigned int len
, dev
;
474 len
= snprintf(path
, sizeof(path
), "backend/%s/%d", type
, dom
);
475 if (strncmp(path
, watch
, len
) != 0) {
478 if (sscanf(watch
+len
, "/%u/%255s", &dev
, path
) != 2) {
480 if (sscanf(watch
+len
, "/%u", &dev
) != 1) {
488 xendev
= xen_be_get_xendev(type
, dom
, dev
, ops
);
489 if (xendev
!= NULL
) {
490 bepath
= xs_read(xenstore
, 0, xendev
->be
, &len
);
491 if (bepath
== NULL
) {
492 xen_pv_del_xendev(xendev
);
495 xen_be_backend_changed(xendev
, path
);
496 xen_be_check_state(xendev
);
501 void xenstore_update_fe(char *watch
, struct XenDevice
*xendev
)
506 len
= strlen(xendev
->fe
);
507 if (strncmp(xendev
->fe
, watch
, len
) != 0) {
510 if (watch
[len
] != '/') {
513 node
= watch
+ len
+ 1;
515 xen_be_frontend_changed(xendev
, node
);
516 xen_be_check_state(xendev
);
518 /* -------------------------------------------------------------------- */
520 int xen_be_init(void)
522 xenstore
= xs_daemon_open();
524 xen_pv_printf(NULL
, 0, "can't connect to xenstored\n");
528 qemu_set_fd_handler(xs_fileno(xenstore
), xenstore_update
, NULL
, NULL
);
530 if (xen_xc
== NULL
|| xen_fmem
== NULL
) {
531 /* Check if xen_init() have been called */
535 xen_sysdev
= qdev_create(NULL
, TYPE_XENSYSDEV
);
536 qdev_init_nofail(xen_sysdev
);
537 xen_sysbus
= qbus_create(TYPE_XENSYSBUS
, DEVICE(xen_sysdev
), "xen-sysbus");
538 qbus_set_bus_hotplug_handler(xen_sysbus
, &error_abort
);
543 qemu_set_fd_handler(xs_fileno(xenstore
), NULL
, NULL
, NULL
);
544 xs_daemon_close(xenstore
);
550 static void xen_set_dynamic_sysbus(void)
552 Object
*machine
= qdev_get_machine();
553 ObjectClass
*oc
= object_get_class(machine
);
554 MachineClass
*mc
= MACHINE_CLASS(oc
);
556 mc
->has_dynamic_sysbus
= true;
559 int xen_be_register(const char *type
, struct XenDevOps
*ops
)
564 if (ops
->backend_register
) {
565 rc
= ops
->backend_register();
571 snprintf(path
, sizeof(path
), "device-model/%u/backends/%s", xen_domid
,
573 xenstore_mkdir(path
, XS_PERM_NONE
);
575 return xenstore_scan(type
, xen_domid
, ops
);
578 void xen_be_register_common(void)
580 xen_set_dynamic_sysbus();
582 xen_be_register("console", &xen_console_ops
);
583 xen_be_register("vkbd", &xen_kbdmouse_ops
);
584 xen_be_register("qdisk", &xen_blkdev_ops
);
586 xen_be_register("9pfs", &xen_9pfs_ops
);
588 #ifdef CONFIG_USB_LIBUSB
589 xen_be_register("qusb", &xen_usb_ops
);
593 int xen_be_bind_evtchn(struct XenDevice
*xendev
)
595 if (xendev
->local_port
!= -1) {
598 xendev
->local_port
= xenevtchn_bind_interdomain
599 (xendev
->evtchndev
, xendev
->dom
, xendev
->remote_port
);
600 if (xendev
->local_port
== -1) {
601 xen_pv_printf(xendev
, 0, "xenevtchn_bind_interdomain failed\n");
604 xen_pv_printf(xendev
, 2, "bind evtchn port %d\n", xendev
->local_port
);
605 qemu_set_fd_handler(xenevtchn_fd(xendev
->evtchndev
),
606 xen_pv_evtchn_event
, NULL
, xendev
);
611 static Property xendev_properties
[] = {
612 DEFINE_PROP_END_OF_LIST(),
615 static void xendev_class_init(ObjectClass
*klass
, void *data
)
617 DeviceClass
*dc
= DEVICE_CLASS(klass
);
619 dc
->props
= xendev_properties
;
620 set_bit(DEVICE_CATEGORY_MISC
, dc
->categories
);
621 /* xen-backend devices can be plugged/unplugged dynamically */
622 dc
->user_creatable
= true;
625 static const TypeInfo xendev_type_info
= {
626 .name
= TYPE_XENBACKEND
,
627 .parent
= TYPE_XENSYSDEV
,
628 .class_init
= xendev_class_init
,
629 .instance_size
= sizeof(struct XenDevice
),
632 static void xen_sysbus_class_init(ObjectClass
*klass
, void *data
)
634 HotplugHandlerClass
*hc
= HOTPLUG_HANDLER_CLASS(klass
);
636 hc
->unplug
= qdev_simple_device_unplug_cb
;
639 static const TypeInfo xensysbus_info
= {
640 .name
= TYPE_XENSYSBUS
,
642 .class_init
= xen_sysbus_class_init
,
643 .interfaces
= (InterfaceInfo
[]) {
644 { TYPE_HOTPLUG_HANDLER
},
649 static int xen_sysdev_init(SysBusDevice
*dev
)
654 static Property xen_sysdev_properties
[] = {
655 {/* end of property list */},
658 static void xen_sysdev_class_init(ObjectClass
*klass
, void *data
)
660 DeviceClass
*dc
= DEVICE_CLASS(klass
);
661 SysBusDeviceClass
*k
= SYS_BUS_DEVICE_CLASS(klass
);
663 k
->init
= xen_sysdev_init
;
664 dc
->props
= xen_sysdev_properties
;
665 dc
->bus_type
= TYPE_XENSYSBUS
;
668 static const TypeInfo xensysdev_info
= {
669 .name
= TYPE_XENSYSDEV
,
670 .parent
= TYPE_SYS_BUS_DEVICE
,
671 .instance_size
= sizeof(SysBusDevice
),
672 .class_init
= xen_sysdev_class_init
,
675 static void xenbe_register_types(void)
677 type_register_static(&xensysbus_info
);
678 type_register_static(&xensysdev_info
);
679 type_register_static(&xendev_type_info
);
682 type_init(xenbe_register_types
)