diff --git a/hw/xen/Makefile.objs b/hw/xen/Makefile.objs index 77c0868190..84df60a928 100644 --- a/hw/xen/Makefile.objs +++ b/hw/xen/Makefile.objs @@ -1,5 +1,5 @@ # xen backend driver support -common-obj-$(CONFIG_XEN) += xen-legacy-backend.o xen_devconfig.o xen_pvdev.o xen-common.o xen-bus.o xen-bus-helper.o +common-obj-$(CONFIG_XEN) += xen-legacy-backend.o xen_devconfig.o xen_pvdev.o xen-common.o xen-bus.o xen-bus-helper.o xen-backend.o obj-$(CONFIG_XEN_PCI_PASSTHROUGH) += xen-host-pci-device.o obj-$(CONFIG_XEN_PCI_PASSTHROUGH) += xen_pt.o xen_pt_config_init.o xen_pt_graphics.o xen_pt_msi.o diff --git a/hw/xen/trace-events b/hw/xen/trace-events index d4651bdb30..f6944624b2 100644 --- a/hw/xen/trace-events +++ b/hw/xen/trace-events @@ -16,6 +16,9 @@ xen_domid_restrict(int err) "err: %u" # include/hw/xen/xen-bus.c xen_bus_realize(void) "" xen_bus_unrealize(void) "" +xen_bus_enumerate(void) "" +xen_bus_type_enumerate(const char *type) "type: %s" +xen_bus_backend_create(const char *type, const char *path) "type: %s path: %s" xen_bus_add_watch(const char *node, const char *key, char *token) "node: %s key: %s token: %s" xen_bus_remove_watch(const char *node, const char *key, char *token) "node: %s key: %s token: %s" xen_bus_watch(const char *token) "token: %s" diff --git a/hw/xen/xen-backend.c b/hw/xen/xen-backend.c new file mode 100644 index 0000000000..da065f81b7 --- /dev/null +++ b/hw/xen/xen-backend.c @@ -0,0 +1,165 @@ +/* + * Copyright (c) 2018 Citrix Systems Inc. + * + * This work is licensed under the terms of the GNU GPL, version 2 or later. + * See the COPYING file in the top-level directory. + */ + +#include "qemu/osdep.h" +#include "qemu/error-report.h" +#include "qapi/error.h" +#include "hw/xen/xen-backend.h" +#include "hw/xen/xen-bus.h" + +typedef struct XenBackendImpl { + const char *type; + XenBackendDeviceCreate create; + XenBackendDeviceDestroy destroy; +} XenBackendImpl; + +struct XenBackendInstance { + QLIST_ENTRY(XenBackendInstance) entry; + const XenBackendImpl *impl; + XenBus *xenbus; + char *name; + XenDevice *xendev; +}; + +static GHashTable *xen_backend_table_get(void) +{ + static GHashTable *table; + + if (table == NULL) { + table = g_hash_table_new(g_str_hash, g_str_equal); + } + + return table; +} + +static void xen_backend_table_add(XenBackendImpl *impl) +{ + g_hash_table_insert(xen_backend_table_get(), (void *)impl->type, impl); +} + +static const XenBackendImpl *xen_backend_table_lookup(const char *type) +{ + return g_hash_table_lookup(xen_backend_table_get(), type); +} + +void xen_backend_register(const XenBackendInfo *info) +{ + XenBackendImpl *impl = g_new0(XenBackendImpl, 1); + + g_assert(info->type); + + if (xen_backend_table_lookup(info->type)) { + error_report("attempt to register duplicate Xen backend type '%s'", + info->type); + abort(); + } + + if (!info->create) { + error_report("backend type '%s' has no creator", info->type); + abort(); + } + + impl->type = info->type; + impl->create = info->create; + impl->destroy = info->destroy; + + xen_backend_table_add(impl); +} + +static QLIST_HEAD(, XenBackendInstance) backend_list; + +static void xen_backend_list_add(XenBackendInstance *backend) +{ + QLIST_INSERT_HEAD(&backend_list, backend, entry); +} + +static XenBackendInstance *xen_backend_list_find(XenDevice *xendev) +{ + XenBackendInstance *backend; + + QLIST_FOREACH(backend, &backend_list, entry) { + if (backend->xendev == xendev) { + return backend; + } + } + + return NULL; +} + +static void xen_backend_list_remove(XenBackendInstance *backend) +{ + QLIST_REMOVE(backend, entry); +} + +void xen_backend_device_create(XenBus *xenbus, const char *type, + const char *name, QDict *opts, Error **errp) +{ + const XenBackendImpl *impl = xen_backend_table_lookup(type); + XenBackendInstance *backend; + Error *local_error = NULL; + + if (!impl) { + return; + } + + backend = g_new0(XenBackendInstance, 1); + backend->xenbus = xenbus; + backend->name = g_strdup(name); + + impl->create(backend, opts, &local_error); + if (local_error) { + error_propagate(errp, local_error); + g_free(backend->name); + g_free(backend); + return; + } + + backend->impl = impl; + xen_backend_list_add(backend); +} + +XenBus *xen_backend_get_bus(XenBackendInstance *backend) +{ + return backend->xenbus; +} + +const char *xen_backend_get_name(XenBackendInstance *backend) +{ + return backend->name; +} + +void xen_backend_set_device(XenBackendInstance *backend, + XenDevice *xendev) +{ + g_assert(!backend->xendev); + backend->xendev = xendev; +} + +XenDevice *xen_backend_get_device(XenBackendInstance *backend) +{ + return backend->xendev; +} + + +bool xen_backend_try_device_destroy(XenDevice *xendev, Error **errp) +{ + XenBackendInstance *backend = xen_backend_list_find(xendev); + const XenBackendImpl *impl; + + if (!backend) { + return false; + } + + impl = backend->impl; + impl->destroy(backend, errp); + + xen_backend_list_remove(backend); + g_free(backend->name); + g_free(backend); + + return true; +} diff --git a/hw/xen/xen-bus.c b/hw/xen/xen-bus.c index 6861ce136e..3aeccec69c 100644 --- a/hw/xen/xen-bus.c +++ b/hw/xen/xen-bus.c @@ -11,10 +11,12 @@ #include "hw/hw.h" #include "hw/sysbus.h" #include "hw/xen/xen.h" +#include "hw/xen/xen-backend.h" #include "hw/xen/xen-bus.h" #include "hw/xen/xen-bus-helper.h" #include "monitor/monitor.h" #include "qapi/error.h" +#include "qapi/qmp/qdict.h" #include "sysemu/sysemu.h" #include "trace.h" @@ -190,12 +192,151 @@ static void xen_bus_remove_watch(XenBus *xenbus, XenWatch *watch, free_watch(watch); } +static void xen_bus_backend_create(XenBus *xenbus, const char *type, + const char *name, char *path, + Error **errp) +{ + xs_transaction_t tid; + char **key; + QDict *opts; + unsigned int i, n; + Error *local_err = NULL; + + trace_xen_bus_backend_create(type, path); + +again: + tid = xs_transaction_start(xenbus->xsh); + if (tid == XBT_NULL) { + error_setg(errp, "failed xs_transaction_start"); + return; + } + + key = xs_directory(xenbus->xsh, tid, path, &n); + if (!key) { + if (!xs_transaction_end(xenbus->xsh, tid, true)) { + error_setg_errno(errp, errno, "failed xs_transaction_end"); + } + return; + } + + opts = qdict_new(); + for (i = 0; i < n; i++) { + char *val; + + /* + * Assume anything found in the xenstore backend area, other than + * the keys created for a generic XenDevice, are parameters + * to be used to configure the backend. + */ + if (!strcmp(key[i], "state") || + !strcmp(key[i], "online") || + !strcmp(key[i], "frontend") || + !strcmp(key[i], "frontend-id") || + !strcmp(key[i], "hotplug-status")) + continue; + + if (xs_node_scanf(xenbus->xsh, tid, path, key[i], NULL, "%ms", + &val) == 1) { + qdict_put_str(opts, key[i], val); + free(val); + } + } + + free(key); + + if (!xs_transaction_end(xenbus->xsh, tid, false)) { + qobject_unref(opts); + + if (errno == EAGAIN) { + goto again; + } + + error_setg_errno(errp, errno, "failed xs_transaction_end"); + return; + } + + xen_backend_device_create(xenbus, type, name, opts, &local_err); + qobject_unref(opts); + + if (local_err) { + error_propagate_prepend(errp, local_err, + "failed to create '%s' device '%s': ", + type, name); + } +} + +static void xen_bus_type_enumerate(XenBus *xenbus, const char *type) +{ + char *domain_path = g_strdup_printf("backend/%s/%u", type, xen_domid); + char **backend; + unsigned int i, n; + + trace_xen_bus_type_enumerate(type); + + backend = xs_directory(xenbus->xsh, XBT_NULL, domain_path, &n); + if (!backend) { + goto out; + } + + for (i = 0; i < n; i++) { + char *backend_path = g_strdup_printf("%s/%s", domain_path, + backend[i]); + enum xenbus_state backend_state; + + if (xs_node_scanf(xenbus->xsh, XBT_NULL, backend_path, "state", + NULL, "%u", &backend_state) != 1) + backend_state = XenbusStateUnknown; + + if (backend_state == XenbusStateInitialising) { + Error *local_err = NULL; + + xen_bus_backend_create(xenbus, type, backend[i], backend_path, + &local_err); + if (local_err) { + error_report_err(local_err); + } + } + + g_free(backend_path); + } + + free(backend); + +out: + g_free(domain_path); +} + +static void xen_bus_enumerate(void *opaque) +{ + XenBus *xenbus = opaque; + char **type; + unsigned int i, n; + + trace_xen_bus_enumerate(); + + type = xs_directory(xenbus->xsh, XBT_NULL, "backend", &n); + if (!type) { + return; + } + + for (i = 0; i < n; i++) { + xen_bus_type_enumerate(xenbus, type[i]); + } + + free(type); +} + static void xen_bus_unrealize(BusState *bus, Error **errp) { XenBus *xenbus = XEN_BUS(bus); trace_xen_bus_unrealize(); + if (xenbus->backend_watch) { + xen_bus_remove_watch(xenbus, xenbus->backend_watch, NULL); + xenbus->backend_watch = NULL; + } + if (!xenbus->xsh) { return; } @@ -231,6 +372,7 @@ static void xen_bus_realize(BusState *bus, Error **errp) { XenBus *xenbus = XEN_BUS(bus); unsigned int domid; + Error *local_err = NULL; trace_xen_bus_realize(); @@ -250,6 +392,18 @@ static void xen_bus_realize(BusState *bus, Error **errp) notifier_list_init(&xenbus->watch_notifiers); qemu_set_fd_handler(xs_fileno(xenbus->xsh), xen_bus_watch, NULL, xenbus); + + module_call_init(MODULE_INIT_XEN_BACKEND); + + xenbus->backend_watch = + xen_bus_add_watch(xenbus, "", /* domain root node */ + "backend", xen_bus_enumerate, xenbus, &local_err); + if (local_err) { + /* This need not be treated as a hard error so don't propagate */ + error_reportf_err(local_err, + "failed to set up enumeration watch: "); + } + return; fail: @@ -407,7 +561,15 @@ static void xen_device_backend_changed(void *opaque) xendev->backend_state == XenbusStateInitialising || xendev->backend_state == XenbusStateInitWait || xendev->backend_state == XenbusStateUnknown)) { - object_unparent(OBJECT(xendev)); + Error *local_err = NULL; + + if (!xen_backend_try_device_destroy(xendev, &local_err)) { + object_unparent(OBJECT(xendev)); + } + + if (local_err) { + error_report_err(local_err); + } } } diff --git a/include/hw/xen/xen-backend.h b/include/hw/xen/xen-backend.h new file mode 100644 index 0000000000..010d712638 --- /dev/null +++ b/include/hw/xen/xen-backend.h @@ -0,0 +1,39 @@ +/* + * Copyright (c) 2018 Citrix Systems Inc. + * + * This work is licensed under the terms of the GNU GPL, version 2 or later. + * See the COPYING file in the top-level directory. + */ + +#ifndef HW_XEN_BACKEND_H +#define HW_XEN_BACKEND_H + +#include "hw/xen/xen-bus.h" + +typedef struct XenBackendInstance XenBackendInstance; + +typedef void (*XenBackendDeviceCreate)(XenBackendInstance *backend, + QDict *opts, Error **errp); +typedef void (*XenBackendDeviceDestroy)(XenBackendInstance *backend, + Error **errp); + +typedef struct XenBackendInfo { + const char *type; + XenBackendDeviceCreate create; + XenBackendDeviceDestroy destroy; +} XenBackendInfo; + +XenBus *xen_backend_get_bus(XenBackendInstance *backend); +const char *xen_backend_get_name(XenBackendInstance *backend); + +void xen_backend_set_device(XenBackendInstance *backend, + XenDevice *xendevice); +XenDevice *xen_backend_get_device(XenBackendInstance *backend); + +void xen_backend_register(const XenBackendInfo *info); + +void xen_backend_device_create(XenBus *xenbus, const char *type, + const char *name, QDict *opts, Error **errp); +bool xen_backend_try_device_destroy(XenDevice *xendev, Error **errp); + +#endif /* HW_XEN_BACKEND_H */ diff --git a/include/hw/xen/xen-bus.h b/include/hw/xen/xen-bus.h index 8f39f88d35..3183f10e3c 100644 --- a/include/hw/xen/xen-bus.h +++ b/include/hw/xen/xen-bus.h @@ -64,6 +64,7 @@ typedef struct XenBus { domid_t backend_id; struct xs_handle *xsh; NotifierList watch_notifiers; + XenWatch *backend_watch; } XenBus; typedef struct XenBusClass { diff --git a/include/qemu/module.h b/include/qemu/module.h index 54300ab6e5..55dd2beea8 100644 --- a/include/qemu/module.h +++ b/include/qemu/module.h @@ -44,6 +44,7 @@ typedef enum { MODULE_INIT_OPTS, MODULE_INIT_QOM, MODULE_INIT_TRACE, + MODULE_INIT_XEN_BACKEND, MODULE_INIT_MAX } module_init_type; @@ -51,6 +52,8 @@ typedef enum { #define opts_init(function) module_init(function, MODULE_INIT_OPTS) #define type_init(function) module_init(function, MODULE_INIT_QOM) #define trace_init(function) module_init(function, MODULE_INIT_TRACE) +#define xen_backend_init(function) module_init(function, \ + MODULE_INIT_XEN_BACKEND) #define block_module_load_one(lib) module_load_one("block-", lib) #define ui_module_load_one(lib) module_load_one("ui-", lib)