/* * xen backend driver infrastructure * (c) 2008 Gerd Hoffmann * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; under version 2 of the License. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License along * with this program; if not, see . * * Contributions after 2012-01-13 are licensed under the terms of the * GNU GPL, version 2 or (at your option) any later version. */ /* * TODO: add some xenbus / xenstore concepts overview here. */ #include "qemu/osdep.h" #include #include "hw/hw.h" #include "hw/sysbus.h" #include "hw/boards.h" #include "qemu/log.h" #include "qapi/error.h" #include "hw/xen/xen-legacy-backend.h" #include "hw/xen/xen_pvdev.h" #include "monitor/qdev.h" DeviceState *xen_sysdev; BusState *xen_sysbus; /* ------------------------------------------------------------- */ /* public */ struct xs_handle *xenstore; const char *xen_protocol; /* private */ static bool xen_feature_grant_copy; static int debug; int xenstore_write_be_str(struct XenLegacyDevice *xendev, const char *node, const char *val) { return xenstore_write_str(xendev->be, node, val); } int xenstore_write_be_int(struct XenLegacyDevice *xendev, const char *node, int ival) { return xenstore_write_int(xendev->be, node, ival); } int xenstore_write_be_int64(struct XenLegacyDevice *xendev, const char *node, int64_t ival) { return xenstore_write_int64(xendev->be, node, ival); } char *xenstore_read_be_str(struct XenLegacyDevice *xendev, const char *node) { return xenstore_read_str(xendev->be, node); } int xenstore_read_be_int(struct XenLegacyDevice *xendev, const char *node, int *ival) { return xenstore_read_int(xendev->be, node, ival); } char *xenstore_read_fe_str(struct XenLegacyDevice *xendev, const char *node) { return xenstore_read_str(xendev->fe, node); } int xenstore_read_fe_int(struct XenLegacyDevice *xendev, const char *node, int *ival) { return xenstore_read_int(xendev->fe, node, ival); } int xenstore_read_fe_uint64(struct XenLegacyDevice *xendev, const char *node, uint64_t *uval) { return xenstore_read_uint64(xendev->fe, node, uval); } /* ------------------------------------------------------------- */ int xen_be_set_state(struct XenLegacyDevice *xendev, enum xenbus_state state) { int rc; rc = xenstore_write_be_int(xendev, "state", state); if (rc < 0) { return rc; } xen_pv_printf(xendev, 1, "backend state: %s -> %s\n", xenbus_strstate(xendev->be_state), xenbus_strstate(state)); xendev->be_state = state; return 0; } void xen_be_set_max_grant_refs(struct XenLegacyDevice *xendev, unsigned int nr_refs) { assert(xendev->ops->flags & DEVOPS_FLAG_NEED_GNTDEV); if (xengnttab_set_max_grants(xendev->gnttabdev, nr_refs)) { xen_pv_printf(xendev, 0, "xengnttab_set_max_grants failed: %s\n", strerror(errno)); } } void *xen_be_map_grant_refs(struct XenLegacyDevice *xendev, uint32_t *refs, unsigned int nr_refs, int prot) { void *ptr; assert(xendev->ops->flags & DEVOPS_FLAG_NEED_GNTDEV); ptr = xengnttab_map_domain_grant_refs(xendev->gnttabdev, nr_refs, xen_domid, refs, prot); if (!ptr) { xen_pv_printf(xendev, 0, "xengnttab_map_domain_grant_refs failed: %s\n", strerror(errno)); } return ptr; } void xen_be_unmap_grant_refs(struct XenLegacyDevice *xendev, void *ptr, unsigned int nr_refs) { assert(xendev->ops->flags & DEVOPS_FLAG_NEED_GNTDEV); if (xengnttab_unmap(xendev->gnttabdev, ptr, nr_refs)) { xen_pv_printf(xendev, 0, "xengnttab_unmap failed: %s\n", strerror(errno)); } } static int compat_copy_grant_refs(struct XenLegacyDevice *xendev, bool to_domain, XenGrantCopySegment segs[], unsigned int nr_segs) { uint32_t *refs = g_new(uint32_t, nr_segs); int prot = to_domain ? PROT_WRITE : PROT_READ; void *pages; unsigned int i; for (i = 0; i < nr_segs; i++) { XenGrantCopySegment *seg = &segs[i]; refs[i] = to_domain ? seg->dest.foreign.ref : seg->source.foreign.ref; } pages = xengnttab_map_domain_grant_refs(xendev->gnttabdev, nr_segs, xen_domid, refs, prot); if (!pages) { xen_pv_printf(xendev, 0, "xengnttab_map_domain_grant_refs failed: %s\n", strerror(errno)); g_free(refs); return -1; } for (i = 0; i < nr_segs; i++) { XenGrantCopySegment *seg = &segs[i]; void *page = pages + (i * XC_PAGE_SIZE); if (to_domain) { memcpy(page + seg->dest.foreign.offset, seg->source.virt, seg->len); } else { memcpy(seg->dest.virt, page + seg->source.foreign.offset, seg->len); } } if (xengnttab_unmap(xendev->gnttabdev, pages, nr_segs)) { xen_pv_printf(xendev, 0, "xengnttab_unmap failed: %s\n", strerror(errno)); } g_free(refs); return 0; } int xen_be_copy_grant_refs(struct XenLegacyDevice *xendev, bool to_domain, XenGrantCopySegment segs[], unsigned int nr_segs) { xengnttab_grant_copy_segment_t *xengnttab_segs; unsigned int i; int rc; assert(xendev->ops->flags & DEVOPS_FLAG_NEED_GNTDEV); if (!xen_feature_grant_copy) { return compat_copy_grant_refs(xendev, to_domain, segs, nr_segs); } xengnttab_segs = g_new0(xengnttab_grant_copy_segment_t, nr_segs); for (i = 0; i < nr_segs; i++) { XenGrantCopySegment *seg = &segs[i]; xengnttab_grant_copy_segment_t *xengnttab_seg = &xengnttab_segs[i]; if (to_domain) { xengnttab_seg->flags = GNTCOPY_dest_gref; xengnttab_seg->dest.foreign.domid = xen_domid; xengnttab_seg->dest.foreign.ref = seg->dest.foreign.ref; xengnttab_seg->dest.foreign.offset = seg->dest.foreign.offset; xengnttab_seg->source.virt = seg->source.virt; } else { xengnttab_seg->flags = GNTCOPY_source_gref; xengnttab_seg->source.foreign.domid = xen_domid; xengnttab_seg->source.foreign.ref = seg->source.foreign.ref; xengnttab_seg->source.foreign.offset = seg->source.foreign.offset; xengnttab_seg->dest.virt = seg->dest.virt; } xengnttab_seg->len = seg->len; } rc = xengnttab_grant_copy(xendev->gnttabdev, nr_segs, xengnttab_segs); if (rc) { xen_pv_printf(xendev, 0, "xengnttab_copy failed: %s\n", strerror(errno)); } for (i = 0; i < nr_segs; i++) { xengnttab_grant_copy_segment_t *xengnttab_seg = &xengnttab_segs[i]; if (xengnttab_seg->status != GNTST_okay) { xen_pv_printf(xendev, 0, "segment[%u] status: %d\n", i, xengnttab_seg->status); rc = -1; } } g_free(xengnttab_segs); return rc; } /* * get xen backend device, allocate a new one if it doesn't exist. */ static struct XenLegacyDevice *xen_be_get_xendev(const char *type, int dom, int dev, struct XenDevOps *ops) { struct XenLegacyDevice *xendev; xendev = xen_pv_find_xendev(type, dom, dev); if (xendev) { return xendev; } /* init new xendev */ xendev = g_malloc0(ops->size); object_initialize(&xendev->qdev, ops->size, TYPE_XENBACKEND); OBJECT(xendev)->free = g_free; qdev_set_parent_bus(DEVICE(xendev), xen_sysbus); qdev_set_id(DEVICE(xendev), g_strdup_printf("xen-%s-%d", type, dev)); qdev_init_nofail(DEVICE(xendev)); object_unref(OBJECT(xendev)); xendev->type = type; xendev->dom = dom; xendev->dev = dev; xendev->ops = ops; snprintf(xendev->be, sizeof(xendev->be), "backend/%s/%d/%d", xendev->type, xendev->dom, xendev->dev); snprintf(xendev->name, sizeof(xendev->name), "%s-%d", xendev->type, xendev->dev); xendev->debug = debug; xendev->local_port = -1; xendev->evtchndev = xenevtchn_open(NULL, 0); if (xendev->evtchndev == NULL) { xen_pv_printf(NULL, 0, "can't open evtchn device\n"); qdev_unplug(DEVICE(xendev), NULL); return NULL; } qemu_set_cloexec(xenevtchn_fd(xendev->evtchndev)); xen_pv_insert_xendev(xendev); if (xendev->ops->alloc) { xendev->ops->alloc(xendev); } return xendev; } /* * Sync internal data structures on xenstore updates. * Node specifies the changed field. node = NULL means * update all fields (used for initialization). */ static void xen_be_backend_changed(struct XenLegacyDevice *xendev, const char *node) { if (node == NULL || strcmp(node, "online") == 0) { if (xenstore_read_be_int(xendev, "online", &xendev->online) == -1) { xendev->online = 0; } } if (node) { xen_pv_printf(xendev, 2, "backend update: %s\n", node); if (xendev->ops->backend_changed) { xendev->ops->backend_changed(xendev, node); } } } static void xen_be_frontend_changed(struct XenLegacyDevice *xendev, const char *node) { int fe_state; if (node == NULL || strcmp(node, "state") == 0) { if (xenstore_read_fe_int(xendev, "state", &fe_state) == -1) { fe_state = XenbusStateUnknown; } if (xendev->fe_state != fe_state) { xen_pv_printf(xendev, 1, "frontend state: %s -> %s\n", xenbus_strstate(xendev->fe_state), xenbus_strstate(fe_state)); } xendev->fe_state = fe_state; } if (node == NULL || strcmp(node, "protocol") == 0) { g_free(xendev->protocol); xendev->protocol = xenstore_read_fe_str(xendev, "protocol"); if (xendev->protocol) { xen_pv_printf(xendev, 1, "frontend protocol: %s\n", xendev->protocol); } } if (node) { xen_pv_printf(xendev, 2, "frontend update: %s\n", node); if (xendev->ops->frontend_changed) { xendev->ops->frontend_changed(xendev, node); } } } /* ------------------------------------------------------------- */ /* Check for possible state transitions and perform them. */ /* * Initial xendev setup. Read frontend path, register watch for it. * Should succeed once xend finished setting up the backend device. * * Also sets initial state (-> Initializing) when done. Which * only affects the xendev->be_state variable as xenbus should * already be put into that state by xend. */ static int xen_be_try_setup(struct XenLegacyDevice *xendev) { char token[XEN_BUFSIZE]; int be_state; if (xenstore_read_be_int(xendev, "state", &be_state) == -1) { xen_pv_printf(xendev, 0, "reading backend state failed\n"); return -1; } if (be_state != XenbusStateInitialising) { xen_pv_printf(xendev, 0, "initial backend state is wrong (%s)\n", xenbus_strstate(be_state)); return -1; } xendev->fe = xenstore_read_be_str(xendev, "frontend"); if (xendev->fe == NULL) { xen_pv_printf(xendev, 0, "reading frontend path failed\n"); return -1; } /* setup frontend watch */ snprintf(token, sizeof(token), "fe:%p", xendev); if (!xs_watch(xenstore, xendev->fe, token)) { xen_pv_printf(xendev, 0, "watching frontend path (%s) failed\n", xendev->fe); return -1; } xen_be_set_state(xendev, XenbusStateInitialising); xen_be_backend_changed(xendev, NULL); xen_be_frontend_changed(xendev, NULL); return 0; } /* * Try initialize xendev. Prepare everything the backend can do * without synchronizing with the frontend. Fakes hotplug-status. No * hotplug involved here because this is about userspace drivers, thus * there are kernel backend devices which could invoke hotplug. * * Goes to InitWait on success. */ static int xen_be_try_init(struct XenLegacyDevice *xendev) { int rc = 0; if (!xendev->online) { xen_pv_printf(xendev, 1, "not online\n"); return -1; } if (xendev->ops->init) { rc = xendev->ops->init(xendev); } if (rc != 0) { xen_pv_printf(xendev, 1, "init() failed\n"); return rc; } xenstore_write_be_str(xendev, "hotplug-status", "connected"); xen_be_set_state(xendev, XenbusStateInitWait); return 0; } /* * Try to initialise xendev. Depends on the frontend being ready * for it (shared ring and evtchn info in xenstore, state being * Initialised or Connected). * * Goes to Connected on success. */ static int xen_be_try_initialise(struct XenLegacyDevice *xendev) { int rc = 0; if (xendev->fe_state != XenbusStateInitialised && xendev->fe_state != XenbusStateConnected) { if (xendev->ops->flags & DEVOPS_FLAG_IGNORE_STATE) { xen_pv_printf(xendev, 2, "frontend not ready, ignoring\n"); } else { xen_pv_printf(xendev, 2, "frontend not ready (yet)\n"); return -1; } } if (xendev->ops->flags & DEVOPS_FLAG_NEED_GNTDEV) { xendev->gnttabdev = xengnttab_open(NULL, 0); if (xendev->gnttabdev == NULL) { xen_pv_printf(NULL, 0, "can't open gnttab device\n"); return -1; } } else { xendev->gnttabdev = NULL; } if (xendev->ops->initialise) { rc = xendev->ops->initialise(xendev); } if (rc != 0) { xen_pv_printf(xendev, 0, "initialise() failed\n"); return rc; } xen_be_set_state(xendev, XenbusStateConnected); return 0; } /* * Try to let xendev know that it is connected. Depends on the * frontend being Connected. Note that this may be called more * than once since the backend state is not modified. */ static void xen_be_try_connected(struct XenLegacyDevice *xendev) { if (!xendev->ops->connected) { return; } if (xendev->fe_state != XenbusStateConnected) { if (xendev->ops->flags & DEVOPS_FLAG_IGNORE_STATE) { xen_pv_printf(xendev, 2, "frontend not ready, ignoring\n"); } else { xen_pv_printf(xendev, 2, "frontend not ready (yet)\n"); return; } } xendev->ops->connected(xendev); } /* * Teardown connection. * * Goes to Closed when done. */ static void xen_be_disconnect(struct XenLegacyDevice *xendev, enum xenbus_state state) { if (xendev->be_state != XenbusStateClosing && xendev->be_state != XenbusStateClosed && xendev->ops->disconnect) { xendev->ops->disconnect(xendev); } if (xendev->gnttabdev) { xengnttab_close(xendev->gnttabdev); xendev->gnttabdev = NULL; } if (xendev->be_state != state) { xen_be_set_state(xendev, state); } } /* * Try to reset xendev, for reconnection by another frontend instance. */ static int xen_be_try_reset(struct XenLegacyDevice *xendev) { if (xendev->fe_state != XenbusStateInitialising) { return -1; } xen_pv_printf(xendev, 1, "device reset (for re-connect)\n"); xen_be_set_state(xendev, XenbusStateInitialising); return 0; } /* * state change dispatcher function */ void xen_be_check_state(struct XenLegacyDevice *xendev) { int rc = 0; /* frontend may request shutdown from almost anywhere */ if (xendev->fe_state == XenbusStateClosing || xendev->fe_state == XenbusStateClosed) { xen_be_disconnect(xendev, xendev->fe_state); return; } /* check for possible backend state transitions */ for (;;) { switch (xendev->be_state) { case XenbusStateUnknown: rc = xen_be_try_setup(xendev); break; case XenbusStateInitialising: rc = xen_be_try_init(xendev); break; case XenbusStateInitWait: rc = xen_be_try_initialise(xendev); break; case XenbusStateConnected: /* xendev->be_state doesn't change */ xen_be_try_connected(xendev); rc = -1; break; case XenbusStateClosed: rc = xen_be_try_reset(xendev); break; default: rc = -1; } if (rc != 0) { break; } } } /* ------------------------------------------------------------- */ static int xenstore_scan(const char *type, int dom, struct XenDevOps *ops) { struct XenLegacyDevice *xendev; char path[XEN_BUFSIZE], token[XEN_BUFSIZE]; char **dev = NULL; unsigned int cdev, j; /* setup watch */ snprintf(token, sizeof(token), "be:%p:%d:%p", type, dom, ops); snprintf(path, sizeof(path), "backend/%s/%d", type, dom); if (!xs_watch(xenstore, path, token)) { xen_pv_printf(NULL, 0, "xen be: watching backend path (%s) failed\n", path); return -1; } /* look for backends */ dev = xs_directory(xenstore, 0, path, &cdev); if (!dev) { return 0; } for (j = 0; j < cdev; j++) { xendev = xen_be_get_xendev(type, dom, atoi(dev[j]), ops); if (xendev == NULL) { continue; } xen_be_check_state(xendev); } free(dev); return 0; } void xenstore_update_be(char *watch, char *type, int dom, struct XenDevOps *ops) { struct XenLegacyDevice *xendev; char path[XEN_BUFSIZE], *bepath; unsigned int len, dev; len = snprintf(path, sizeof(path), "backend/%s/%d", type, dom); if (strncmp(path, watch, len) != 0) { return; } if (sscanf(watch + len, "/%u/%255s", &dev, path) != 2) { strcpy(path, ""); if (sscanf(watch + len, "/%u", &dev) != 1) { dev = -1; } } if (dev == -1) { return; } xendev = xen_be_get_xendev(type, dom, dev, ops); if (xendev != NULL) { bepath = xs_read(xenstore, 0, xendev->be, &len); if (bepath == NULL) { xen_pv_del_xendev(xendev); } else { free(bepath); xen_be_backend_changed(xendev, path); xen_be_check_state(xendev); } } } void xenstore_update_fe(char *watch, struct XenLegacyDevice *xendev) { char *node; unsigned int len; len = strlen(xendev->fe); if (strncmp(xendev->fe, watch, len) != 0) { return; } if (watch[len] != '/') { return; } node = watch + len + 1; xen_be_frontend_changed(xendev, node); xen_be_check_state(xendev); } /* -------------------------------------------------------------------- */ int xen_be_init(void) { xengnttab_handle *gnttabdev; xenstore = xs_daemon_open(); if (!xenstore) { xen_pv_printf(NULL, 0, "can't connect to xenstored\n"); return -1; } qemu_set_fd_handler(xs_fileno(xenstore), xenstore_update, NULL, NULL); if (xen_xc == NULL || xen_fmem == NULL) { /* Check if xen_init() have been called */ goto err; } gnttabdev = xengnttab_open(NULL, 0); if (gnttabdev != NULL) { if (xengnttab_grant_copy(gnttabdev, 0, NULL) == 0) { xen_feature_grant_copy = true; } xengnttab_close(gnttabdev); } xen_sysdev = qdev_create(NULL, TYPE_XENSYSDEV); qdev_init_nofail(xen_sysdev); xen_sysbus = qbus_create(TYPE_XENSYSBUS, DEVICE(xen_sysdev), "xen-sysbus"); qbus_set_bus_hotplug_handler(xen_sysbus, &error_abort); return 0; err: qemu_set_fd_handler(xs_fileno(xenstore), NULL, NULL, NULL); xs_daemon_close(xenstore); xenstore = NULL; return -1; } static void xen_set_dynamic_sysbus(void) { Object *machine = qdev_get_machine(); ObjectClass *oc = object_get_class(machine); MachineClass *mc = MACHINE_CLASS(oc); machine_class_allow_dynamic_sysbus_dev(mc, TYPE_XENSYSDEV); } int xen_be_register(const char *type, struct XenDevOps *ops) { char path[50]; int rc; if (ops->backend_register) { rc = ops->backend_register(); if (rc) { return rc; } } snprintf(path, sizeof(path), "device-model/%u/backends/%s", xen_domid, type); xenstore_mkdir(path, XS_PERM_NONE); return xenstore_scan(type, xen_domid, ops); } void xen_be_register_common(void) { xen_set_dynamic_sysbus(); xen_be_register("console", &xen_console_ops); xen_be_register("vkbd", &xen_kbdmouse_ops); #ifdef CONFIG_VIRTFS xen_be_register("9pfs", &xen_9pfs_ops); #endif #ifdef CONFIG_USB_LIBUSB xen_be_register("qusb", &xen_usb_ops); #endif } int xen_be_bind_evtchn(struct XenLegacyDevice *xendev) { if (xendev->local_port != -1) { return 0; } xendev->local_port = xenevtchn_bind_interdomain (xendev->evtchndev, xendev->dom, xendev->remote_port); if (xendev->local_port == -1) { xen_pv_printf(xendev, 0, "xenevtchn_bind_interdomain failed\n"); return -1; } xen_pv_printf(xendev, 2, "bind evtchn port %d\n", xendev->local_port); qemu_set_fd_handler(xenevtchn_fd(xendev->evtchndev), xen_pv_evtchn_event, NULL, xendev); return 0; } static Property xendev_properties[] = { DEFINE_PROP_END_OF_LIST(), }; static void xendev_class_init(ObjectClass *klass, void *data) { DeviceClass *dc = DEVICE_CLASS(klass); dc->props = xendev_properties; set_bit(DEVICE_CATEGORY_MISC, dc->categories); /* xen-backend devices can be plugged/unplugged dynamically */ dc->user_creatable = true; } static const TypeInfo xendev_type_info = { .name = TYPE_XENBACKEND, .parent = TYPE_XENSYSDEV, .class_init = xendev_class_init, .instance_size = sizeof(struct XenLegacyDevice), }; static void xen_sysbus_class_init(ObjectClass *klass, void *data) { HotplugHandlerClass *hc = HOTPLUG_HANDLER_CLASS(klass); hc->unplug = qdev_simple_device_unplug_cb; } static const TypeInfo xensysbus_info = { .name = TYPE_XENSYSBUS, .parent = TYPE_BUS, .class_init = xen_sysbus_class_init, .interfaces = (InterfaceInfo[]) { { TYPE_HOTPLUG_HANDLER }, { } } }; static Property xen_sysdev_properties[] = { {/* end of property list */}, }; static void xen_sysdev_class_init(ObjectClass *klass, void *data) { DeviceClass *dc = DEVICE_CLASS(klass); dc->props = xen_sysdev_properties; dc->bus_type = TYPE_XENSYSBUS; } static const TypeInfo xensysdev_info = { .name = TYPE_XENSYSDEV, .parent = TYPE_SYS_BUS_DEVICE, .instance_size = sizeof(SysBusDevice), .class_init = xen_sysdev_class_init, }; static void xenbe_register_types(void) { type_register_static(&xensysbus_info); type_register_static(&xensysdev_info); type_register_static(&xendev_type_info); } type_init(xenbe_register_types)