2 * xen backend driver infrastructure
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>
28 #include "hw/sysbus.h"
29 #include "hw/boards.h"
31 #include "qapi/error.h"
32 #include "hw/xen/xen-legacy-backend.h"
33 #include "hw/xen/xen_pvdev.h"
34 #include "monitor/qdev.h"
36 DeviceState *xen_sysdev;
39 /* ------------------------------------------------------------- */
42 struct xs_handle *xenstore;
43 const char *xen_protocol;
46 static bool xen_feature_grant_copy;
49 int xenstore_write_be_str(struct XenLegacyDevice *xendev, const char *node,
52 return xenstore_write_str(xendev->be, node, val);
55 int xenstore_write_be_int(struct XenLegacyDevice *xendev, const char *node,
58 return xenstore_write_int(xendev->be, node, ival);
61 int xenstore_write_be_int64(struct XenLegacyDevice *xendev, const char *node,
64 return xenstore_write_int64(xendev->be, node, ival);
67 char *xenstore_read_be_str(struct XenLegacyDevice *xendev, const char *node)
69 return xenstore_read_str(xendev->be, node);
72 int xenstore_read_be_int(struct XenLegacyDevice *xendev, const char *node,
75 return xenstore_read_int(xendev->be, node, ival);
78 char *xenstore_read_fe_str(struct XenLegacyDevice *xendev, const char *node)
80 return xenstore_read_str(xendev->fe, node);
83 int xenstore_read_fe_int(struct XenLegacyDevice *xendev, const char *node,
86 return xenstore_read_int(xendev->fe, node, ival);
89 int xenstore_read_fe_uint64(struct XenLegacyDevice *xendev, const char *node,
92 return xenstore_read_uint64(xendev->fe, node, uval);
95 /* ------------------------------------------------------------- */
97 int xen_be_set_state(struct XenLegacyDevice *xendev, enum xenbus_state state)
101 rc = xenstore_write_be_int(xendev, "state", state);
105 xen_pv_printf(xendev, 1, "backend state: %s -> %s\n",
106 xenbus_strstate(xendev->be_state), xenbus_strstate(state));
107 xendev->be_state = state;
111 void xen_be_set_max_grant_refs(struct XenLegacyDevice *xendev,
112 unsigned int nr_refs)
114 assert(xendev->ops->flags & DEVOPS_FLAG_NEED_GNTDEV);
116 if (xengnttab_set_max_grants(xendev->gnttabdev, nr_refs)) {
117 xen_pv_printf(xendev, 0, "xengnttab_set_max_grants failed: %s\n",
122 void *xen_be_map_grant_refs(struct XenLegacyDevice *xendev, uint32_t *refs,
123 unsigned int nr_refs, int prot)
127 assert(xendev->ops->flags & DEVOPS_FLAG_NEED_GNTDEV);
129 ptr = xengnttab_map_domain_grant_refs(xendev->gnttabdev, nr_refs,
130 xen_domid, refs, prot);
132 xen_pv_printf(xendev, 0,
133 "xengnttab_map_domain_grant_refs failed: %s\n",
140 void xen_be_unmap_grant_refs(struct XenLegacyDevice *xendev, void *ptr,
141 unsigned int nr_refs)
143 assert(xendev->ops->flags & DEVOPS_FLAG_NEED_GNTDEV);
145 if (xengnttab_unmap(xendev->gnttabdev, ptr, nr_refs)) {
146 xen_pv_printf(xendev, 0, "xengnttab_unmap failed: %s\n",
151 static int compat_copy_grant_refs(struct XenLegacyDevice *xendev,
153 XenGrantCopySegment segs[],
154 unsigned int nr_segs)
156 uint32_t *refs = g_new(uint32_t, nr_segs);
157 int prot = to_domain ? PROT_WRITE : PROT_READ;
161 for (i = 0; i < nr_segs; i++) {
162 XenGrantCopySegment *seg = &segs[i];
164 refs[i] = to_domain ?
165 seg->dest.foreign.ref : seg->source.foreign.ref;
168 pages = xengnttab_map_domain_grant_refs(xendev->gnttabdev, nr_segs,
169 xen_domid, refs, prot);
171 xen_pv_printf(xendev, 0,
172 "xengnttab_map_domain_grant_refs failed: %s\n",
178 for (i = 0; i < nr_segs; i++) {
179 XenGrantCopySegment *seg = &segs[i];
180 void *page = pages + (i * XC_PAGE_SIZE);
183 memcpy(page + seg->dest.foreign.offset, seg->source.virt,
186 memcpy(seg->dest.virt, page + seg->source.foreign.offset,
191 if (xengnttab_unmap(xendev->gnttabdev, pages, nr_segs)) {
192 xen_pv_printf(xendev, 0, "xengnttab_unmap failed: %s\n",
200 int xen_be_copy_grant_refs(struct XenLegacyDevice *xendev,
202 XenGrantCopySegment segs[],
203 unsigned int nr_segs)
205 xengnttab_grant_copy_segment_t *xengnttab_segs;
209 assert(xendev->ops->flags & DEVOPS_FLAG_NEED_GNTDEV);
211 if (!xen_feature_grant_copy) {
212 return compat_copy_grant_refs(xendev, to_domain, segs, nr_segs);
215 xengnttab_segs = g_new0(xengnttab_grant_copy_segment_t, nr_segs);
217 for (i = 0; i < nr_segs; i++) {
218 XenGrantCopySegment *seg = &segs[i];
219 xengnttab_grant_copy_segment_t *xengnttab_seg = &xengnttab_segs[i];
222 xengnttab_seg->flags = GNTCOPY_dest_gref;
223 xengnttab_seg->dest.foreign.domid = xen_domid;
224 xengnttab_seg->dest.foreign.ref = seg->dest.foreign.ref;
225 xengnttab_seg->dest.foreign.offset = seg->dest.foreign.offset;
226 xengnttab_seg->source.virt = seg->source.virt;
228 xengnttab_seg->flags = GNTCOPY_source_gref;
229 xengnttab_seg->source.foreign.domid = xen_domid;
230 xengnttab_seg->source.foreign.ref = seg->source.foreign.ref;
231 xengnttab_seg->source.foreign.offset =
232 seg->source.foreign.offset;
233 xengnttab_seg->dest.virt = seg->dest.virt;
236 xengnttab_seg->len = seg->len;
239 rc = xengnttab_grant_copy(xendev->gnttabdev, nr_segs, xengnttab_segs);
242 xen_pv_printf(xendev, 0, "xengnttab_copy failed: %s\n",
246 for (i = 0; i < nr_segs; i++) {
247 xengnttab_grant_copy_segment_t *xengnttab_seg =
250 if (xengnttab_seg->status != GNTST_okay) {
251 xen_pv_printf(xendev, 0, "segment[%u] status: %d\n", i,
252 xengnttab_seg->status);
257 g_free(xengnttab_segs);
262 * get xen backend device, allocate a new one if it doesn't exist.
264 static struct XenLegacyDevice *xen_be_get_xendev(const char *type, int dom,
266 struct XenDevOps *ops)
268 struct XenLegacyDevice *xendev;
270 xendev = xen_pv_find_xendev(type, dom, dev);
275 /* init new xendev */
276 xendev = g_malloc0(ops->size);
277 object_initialize(&xendev->qdev, ops->size, TYPE_XENBACKEND);
278 OBJECT(xendev)->free = g_free;
279 qdev_set_parent_bus(DEVICE(xendev), xen_sysbus);
280 qdev_set_id(DEVICE(xendev), g_strdup_printf("xen-%s-%d", type, dev));
281 qdev_init_nofail(DEVICE(xendev));
282 object_unref(OBJECT(xendev));
289 snprintf(xendev->be, sizeof(xendev->be), "backend/%s/%d/%d",
290 xendev->type, xendev->dom, xendev->dev);
291 snprintf(xendev->name, sizeof(xendev->name), "%s-%d",
292 xendev->type, xendev->dev);
294 xendev->debug = debug;
295 xendev->local_port = -1;
297 xendev->evtchndev = xenevtchn_open(NULL, 0);
298 if (xendev->evtchndev == NULL) {
299 xen_pv_printf(NULL, 0, "can't open evtchn device\n");
300 qdev_unplug(DEVICE(xendev), NULL);
303 qemu_set_cloexec(xenevtchn_fd(xendev->evtchndev));
305 xen_pv_insert_xendev(xendev);
307 if (xendev->ops->alloc) {
308 xendev->ops->alloc(xendev);
316 * Sync internal data structures on xenstore updates.
317 * Node specifies the changed field. node = NULL means
318 * update all fields (used for initialization).
320 static void xen_be_backend_changed(struct XenLegacyDevice *xendev,
323 if (node == NULL || strcmp(node, "online") == 0) {
324 if (xenstore_read_be_int(xendev, "online", &xendev->online) == -1) {
330 xen_pv_printf(xendev, 2, "backend update: %s\n", node);
331 if (xendev->ops->backend_changed) {
332 xendev->ops->backend_changed(xendev, node);
337 static void xen_be_frontend_changed(struct XenLegacyDevice *xendev,
342 if (node == NULL || strcmp(node, "state") == 0) {
343 if (xenstore_read_fe_int(xendev, "state", &fe_state) == -1) {
344 fe_state = XenbusStateUnknown;
346 if (xendev->fe_state != fe_state) {
347 xen_pv_printf(xendev, 1, "frontend state: %s -> %s\n",
348 xenbus_strstate(xendev->fe_state),
349 xenbus_strstate(fe_state));
351 xendev->fe_state = fe_state;
353 if (node == NULL || strcmp(node, "protocol") == 0) {
354 g_free(xendev->protocol);
355 xendev->protocol = xenstore_read_fe_str(xendev, "protocol");
356 if (xendev->protocol) {
357 xen_pv_printf(xendev, 1, "frontend protocol: %s\n",
363 xen_pv_printf(xendev, 2, "frontend update: %s\n", node);
364 if (xendev->ops->frontend_changed) {
365 xendev->ops->frontend_changed(xendev, node);
370 /* ------------------------------------------------------------- */
371 /* Check for possible state transitions and perform them. */
374 * Initial xendev setup. Read frontend path, register watch for it.
375 * Should succeed once xend finished setting up the backend device.
377 * Also sets initial state (-> Initializing) when done. Which
378 * only affects the xendev->be_state variable as xenbus should
379 * already be put into that state by xend.
381 static int xen_be_try_setup(struct XenLegacyDevice *xendev)
383 char token[XEN_BUFSIZE];
386 if (xenstore_read_be_int(xendev, "state", &be_state) == -1) {
387 xen_pv_printf(xendev, 0, "reading backend state failed\n");
391 if (be_state != XenbusStateInitialising) {
392 xen_pv_printf(xendev, 0, "initial backend state is wrong (%s)\n",
393 xenbus_strstate(be_state));
397 xendev->fe = xenstore_read_be_str(xendev, "frontend");
398 if (xendev->fe == NULL) {
399 xen_pv_printf(xendev, 0, "reading frontend path failed\n");
403 /* setup frontend watch */
404 snprintf(token, sizeof(token), "fe:%p", xendev);
405 if (!xs_watch(xenstore, xendev->fe, token)) {
406 xen_pv_printf(xendev, 0, "watching frontend path (%s) failed\n",
410 xen_be_set_state(xendev, XenbusStateInitialising);
412 xen_be_backend_changed(xendev, NULL);
413 xen_be_frontend_changed(xendev, NULL);
418 * Try initialize xendev. Prepare everything the backend can do
419 * without synchronizing with the frontend. Fakes hotplug-status. No
420 * hotplug involved here because this is about userspace drivers, thus
421 * there are kernel backend devices which could invoke hotplug.
423 * Goes to InitWait on success.
425 static int xen_be_try_init(struct XenLegacyDevice *xendev)
429 if (!xendev->online) {
430 xen_pv_printf(xendev, 1, "not online\n");
434 if (xendev->ops->init) {
435 rc = xendev->ops->init(xendev);
438 xen_pv_printf(xendev, 1, "init() failed\n");
442 xenstore_write_be_str(xendev, "hotplug-status", "connected");
443 xen_be_set_state(xendev, XenbusStateInitWait);
448 * Try to initialise xendev. Depends on the frontend being ready
449 * for it (shared ring and evtchn info in xenstore, state being
450 * Initialised or Connected).
452 * Goes to Connected on success.
454 static int xen_be_try_initialise(struct XenLegacyDevice *xendev)
458 if (xendev->fe_state != XenbusStateInitialised &&
459 xendev->fe_state != XenbusStateConnected) {
460 if (xendev->ops->flags & DEVOPS_FLAG_IGNORE_STATE) {
461 xen_pv_printf(xendev, 2, "frontend not ready, ignoring\n");
463 xen_pv_printf(xendev, 2, "frontend not ready (yet)\n");
468 if (xendev->ops->flags & DEVOPS_FLAG_NEED_GNTDEV) {
469 xendev->gnttabdev = xengnttab_open(NULL, 0);
470 if (xendev->gnttabdev == NULL) {
471 xen_pv_printf(NULL, 0, "can't open gnttab device\n");
475 xendev->gnttabdev = NULL;
478 if (xendev->ops->initialise) {
479 rc = xendev->ops->initialise(xendev);
482 xen_pv_printf(xendev, 0, "initialise() failed\n");
486 xen_be_set_state(xendev, XenbusStateConnected);
491 * Try to let xendev know that it is connected. Depends on the
492 * frontend being Connected. Note that this may be called more
493 * than once since the backend state is not modified.
495 static void xen_be_try_connected(struct XenLegacyDevice *xendev)
497 if (!xendev->ops->connected) {
501 if (xendev->fe_state != XenbusStateConnected) {
502 if (xendev->ops->flags & DEVOPS_FLAG_IGNORE_STATE) {
503 xen_pv_printf(xendev, 2, "frontend not ready, ignoring\n");
505 xen_pv_printf(xendev, 2, "frontend not ready (yet)\n");
510 xendev->ops->connected(xendev);
514 * Teardown connection.
516 * Goes to Closed when done.
518 static void xen_be_disconnect(struct XenLegacyDevice *xendev,
519 enum xenbus_state state)
521 if (xendev->be_state != XenbusStateClosing &&
522 xendev->be_state != XenbusStateClosed &&
523 xendev->ops->disconnect) {
524 xendev->ops->disconnect(xendev);
526 if (xendev->gnttabdev) {
527 xengnttab_close(xendev->gnttabdev);
528 xendev->gnttabdev = NULL;
530 if (xendev->be_state != state) {
531 xen_be_set_state(xendev, state);
536 * Try to reset xendev, for reconnection by another frontend instance.
538 static int xen_be_try_reset(struct XenLegacyDevice *xendev)
540 if (xendev->fe_state != XenbusStateInitialising) {
544 xen_pv_printf(xendev, 1, "device reset (for re-connect)\n");
545 xen_be_set_state(xendev, XenbusStateInitialising);
550 * state change dispatcher function
552 void xen_be_check_state(struct XenLegacyDevice *xendev)
556 /* frontend may request shutdown from almost anywhere */
557 if (xendev->fe_state == XenbusStateClosing ||
558 xendev->fe_state == XenbusStateClosed) {
559 xen_be_disconnect(xendev, xendev->fe_state);
563 /* check for possible backend state transitions */
565 switch (xendev->be_state) {
566 case XenbusStateUnknown:
567 rc = xen_be_try_setup(xendev);
569 case XenbusStateInitialising:
570 rc = xen_be_try_init(xendev);
572 case XenbusStateInitWait:
573 rc = xen_be_try_initialise(xendev);
575 case XenbusStateConnected:
576 /* xendev->be_state doesn't change */
577 xen_be_try_connected(xendev);
580 case XenbusStateClosed:
581 rc = xen_be_try_reset(xendev);
592 /* ------------------------------------------------------------- */
594 static int xenstore_scan(const char *type, int dom, struct XenDevOps *ops)
596 struct XenLegacyDevice *xendev;
597 char path[XEN_BUFSIZE], token[XEN_BUFSIZE];
599 unsigned int cdev, j;
602 snprintf(token, sizeof(token), "be:%p:%d:%p", type, dom, ops);
603 snprintf(path, sizeof(path), "backend/%s/%d", type, dom);
604 if (!xs_watch(xenstore, path, token)) {
605 xen_pv_printf(NULL, 0, "xen be: watching backend path (%s) failed\n",
610 /* look for backends */
611 dev = xs_directory(xenstore, 0, path, &cdev);
615 for (j = 0; j < cdev; j++) {
616 xendev = xen_be_get_xendev(type, dom, atoi(dev[j]), ops);
617 if (xendev == NULL) {
620 xen_be_check_state(xendev);
626 void xenstore_update_be(char *watch, char *type, int dom,
627 struct XenDevOps *ops)
629 struct XenLegacyDevice *xendev;
630 char path[XEN_BUFSIZE], *bepath;
631 unsigned int len, dev;
633 len = snprintf(path, sizeof(path), "backend/%s/%d", type, dom);
634 if (strncmp(path, watch, len) != 0) {
637 if (sscanf(watch + len, "/%u/%255s", &dev, path) != 2) {
639 if (sscanf(watch + len, "/%u", &dev) != 1) {
647 xendev = xen_be_get_xendev(type, dom, dev, ops);
648 if (xendev != NULL) {
649 bepath = xs_read(xenstore, 0, xendev->be, &len);
650 if (bepath == NULL) {
651 xen_pv_del_xendev(xendev);
654 xen_be_backend_changed(xendev, path);
655 xen_be_check_state(xendev);
660 void xenstore_update_fe(char *watch, struct XenLegacyDevice *xendev)
665 len = strlen(xendev->fe);
666 if (strncmp(xendev->fe, watch, len) != 0) {
669 if (watch[len] != '/') {
672 node = watch + len + 1;
674 xen_be_frontend_changed(xendev, node);
675 xen_be_check_state(xendev);
677 /* -------------------------------------------------------------------- */
679 int xen_be_init(void)
681 xengnttab_handle *gnttabdev;
683 xenstore = xs_daemon_open();
685 xen_pv_printf(NULL, 0, "can't connect to xenstored\n");
689 qemu_set_fd_handler(xs_fileno(xenstore), xenstore_update, NULL, NULL);
691 if (xen_xc == NULL || xen_fmem == NULL) {
692 /* Check if xen_init() have been called */
696 gnttabdev = xengnttab_open(NULL, 0);
697 if (gnttabdev != NULL) {
698 if (xengnttab_grant_copy(gnttabdev, 0, NULL) == 0) {
699 xen_feature_grant_copy = true;
701 xengnttab_close(gnttabdev);
704 xen_sysdev = qdev_create(NULL, TYPE_XENSYSDEV);
705 qdev_init_nofail(xen_sysdev);
706 xen_sysbus = qbus_create(TYPE_XENSYSBUS, DEVICE(xen_sysdev), "xen-sysbus");
707 qbus_set_bus_hotplug_handler(xen_sysbus, &error_abort);
712 qemu_set_fd_handler(xs_fileno(xenstore), NULL, NULL, NULL);
713 xs_daemon_close(xenstore);
719 static void xen_set_dynamic_sysbus(void)
721 Object *machine = qdev_get_machine();
722 ObjectClass *oc = object_get_class(machine);
723 MachineClass *mc = MACHINE_CLASS(oc);
725 machine_class_allow_dynamic_sysbus_dev(mc, TYPE_XENSYSDEV);
728 int xen_be_register(const char *type, struct XenDevOps *ops)
733 if (ops->backend_register) {
734 rc = ops->backend_register();
740 snprintf(path, sizeof(path), "device-model/%u/backends/%s", xen_domid,
742 xenstore_mkdir(path, XS_PERM_NONE);
744 return xenstore_scan(type, xen_domid, ops);
747 void xen_be_register_common(void)
749 xen_set_dynamic_sysbus();
751 xen_be_register("console", &xen_console_ops);
752 xen_be_register("vkbd", &xen_kbdmouse_ops);
754 xen_be_register("9pfs", &xen_9pfs_ops);
756 #ifdef CONFIG_USB_LIBUSB
757 xen_be_register("qusb", &xen_usb_ops);
761 int xen_be_bind_evtchn(struct XenLegacyDevice *xendev)
763 if (xendev->local_port != -1) {
766 xendev->local_port = xenevtchn_bind_interdomain
767 (xendev->evtchndev, xendev->dom, xendev->remote_port);
768 if (xendev->local_port == -1) {
769 xen_pv_printf(xendev, 0, "xenevtchn_bind_interdomain failed\n");
772 xen_pv_printf(xendev, 2, "bind evtchn port %d\n", xendev->local_port);
773 qemu_set_fd_handler(xenevtchn_fd(xendev->evtchndev),
774 xen_pv_evtchn_event, NULL, xendev);
779 static Property xendev_properties[] = {
780 DEFINE_PROP_END_OF_LIST(),
783 static void xendev_class_init(ObjectClass *klass, void *data)
785 DeviceClass *dc = DEVICE_CLASS(klass);
787 dc->props = xendev_properties;
788 set_bit(DEVICE_CATEGORY_MISC, dc->categories);
789 /* xen-backend devices can be plugged/unplugged dynamically */
790 dc->user_creatable = true;
793 static const TypeInfo xendev_type_info = {
794 .name = TYPE_XENBACKEND,
795 .parent = TYPE_XENSYSDEV,
796 .class_init = xendev_class_init,
797 .instance_size = sizeof(struct XenLegacyDevice),
800 static void xen_sysbus_class_init(ObjectClass *klass, void *data)
802 HotplugHandlerClass *hc = HOTPLUG_HANDLER_CLASS(klass);
804 hc->unplug = qdev_simple_device_unplug_cb;
807 static const TypeInfo xensysbus_info = {
808 .name = TYPE_XENSYSBUS,
810 .class_init = xen_sysbus_class_init,
811 .interfaces = (InterfaceInfo[]) {
812 { TYPE_HOTPLUG_HANDLER },
817 static Property xen_sysdev_properties[] = {
818 {/* end of property list */},
821 static void xen_sysdev_class_init(ObjectClass *klass, void *data)
823 DeviceClass *dc = DEVICE_CLASS(klass);
825 dc->props = xen_sysdev_properties;
826 dc->bus_type = TYPE_XENSYSBUS;
829 static const TypeInfo xensysdev_info = {
830 .name = TYPE_XENSYSDEV,
831 .parent = TYPE_SYS_BUS_DEVICE,
832 .instance_size = sizeof(SysBusDevice),
833 .class_init = xen_sysdev_class_init,
836 static void xenbe_register_types(void)
838 type_register_static(&xensysbus_info);
839 type_register_static(&xensysdev_info);
840 type_register_static(&xendev_type_info);
843 type_init(xenbe_register_types)