Paul Durrant | a783f8a | 2019-01-08 14:49:00 +0000 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (c) 2018 Citrix Systems Inc. |
| 3 | * |
| 4 | * This work is licensed under the terms of the GNU GPL, version 2 or later. |
| 5 | * See the COPYING file in the top-level directory. |
| 6 | */ |
| 7 | |
| 8 | #include "qemu/osdep.h" |
| 9 | #include "qemu/error-report.h" |
| 10 | #include "qapi/error.h" |
| 11 | #include "hw/xen/xen-backend.h" |
| 12 | #include "hw/xen/xen-bus.h" |
| 13 | |
| 14 | typedef struct XenBackendImpl { |
| 15 | const char *type; |
| 16 | XenBackendDeviceCreate create; |
| 17 | XenBackendDeviceDestroy destroy; |
| 18 | } XenBackendImpl; |
| 19 | |
| 20 | struct XenBackendInstance { |
| 21 | QLIST_ENTRY(XenBackendInstance) entry; |
| 22 | const XenBackendImpl *impl; |
| 23 | XenBus *xenbus; |
| 24 | char *name; |
| 25 | XenDevice *xendev; |
| 26 | }; |
| 27 | |
| 28 | static GHashTable *xen_backend_table_get(void) |
| 29 | { |
| 30 | static GHashTable *table; |
| 31 | |
| 32 | if (table == NULL) { |
| 33 | table = g_hash_table_new(g_str_hash, g_str_equal); |
| 34 | } |
| 35 | |
| 36 | return table; |
| 37 | } |
| 38 | |
| 39 | static void xen_backend_table_add(XenBackendImpl *impl) |
| 40 | { |
| 41 | g_hash_table_insert(xen_backend_table_get(), (void *)impl->type, impl); |
| 42 | } |
| 43 | |
Paul Durrant | c4583c8 | 2020-10-01 09:15:00 +0100 | [diff] [blame] | 44 | static const char **xen_backend_table_keys(unsigned int *count) |
| 45 | { |
| 46 | return (const char **)g_hash_table_get_keys_as_array( |
| 47 | xen_backend_table_get(), count); |
| 48 | } |
| 49 | |
Paul Durrant | a783f8a | 2019-01-08 14:49:00 +0000 | [diff] [blame] | 50 | static const XenBackendImpl *xen_backend_table_lookup(const char *type) |
| 51 | { |
| 52 | return g_hash_table_lookup(xen_backend_table_get(), type); |
| 53 | } |
| 54 | |
| 55 | void xen_backend_register(const XenBackendInfo *info) |
| 56 | { |
| 57 | XenBackendImpl *impl = g_new0(XenBackendImpl, 1); |
| 58 | |
| 59 | g_assert(info->type); |
| 60 | |
| 61 | if (xen_backend_table_lookup(info->type)) { |
| 62 | error_report("attempt to register duplicate Xen backend type '%s'", |
| 63 | info->type); |
| 64 | abort(); |
| 65 | } |
| 66 | |
| 67 | if (!info->create) { |
| 68 | error_report("backend type '%s' has no creator", info->type); |
| 69 | abort(); |
| 70 | } |
| 71 | |
| 72 | impl->type = info->type; |
| 73 | impl->create = info->create; |
| 74 | impl->destroy = info->destroy; |
| 75 | |
| 76 | xen_backend_table_add(impl); |
| 77 | } |
| 78 | |
Paul Durrant | c4583c8 | 2020-10-01 09:15:00 +0100 | [diff] [blame] | 79 | const char **xen_backend_get_types(unsigned int *count) |
| 80 | { |
| 81 | return xen_backend_table_keys(count); |
| 82 | } |
| 83 | |
Paul Durrant | a783f8a | 2019-01-08 14:49:00 +0000 | [diff] [blame] | 84 | static QLIST_HEAD(, XenBackendInstance) backend_list; |
| 85 | |
| 86 | static void xen_backend_list_add(XenBackendInstance *backend) |
| 87 | { |
| 88 | QLIST_INSERT_HEAD(&backend_list, backend, entry); |
| 89 | } |
| 90 | |
| 91 | static XenBackendInstance *xen_backend_list_find(XenDevice *xendev) |
| 92 | { |
| 93 | XenBackendInstance *backend; |
| 94 | |
| 95 | QLIST_FOREACH(backend, &backend_list, entry) { |
| 96 | if (backend->xendev == xendev) { |
| 97 | return backend; |
| 98 | } |
| 99 | } |
| 100 | |
| 101 | return NULL; |
| 102 | } |
| 103 | |
| 104 | static void xen_backend_list_remove(XenBackendInstance *backend) |
| 105 | { |
| 106 | QLIST_REMOVE(backend, entry); |
| 107 | } |
| 108 | |
| 109 | void xen_backend_device_create(XenBus *xenbus, const char *type, |
| 110 | const char *name, QDict *opts, Error **errp) |
| 111 | { |
Vladimir Sementsov-Ogievskiy | 1de7096 | 2020-07-07 18:50:37 +0200 | [diff] [blame] | 112 | ERRP_GUARD(); |
Paul Durrant | a783f8a | 2019-01-08 14:49:00 +0000 | [diff] [blame] | 113 | const XenBackendImpl *impl = xen_backend_table_lookup(type); |
| 114 | XenBackendInstance *backend; |
Paul Durrant | a783f8a | 2019-01-08 14:49:00 +0000 | [diff] [blame] | 115 | |
| 116 | if (!impl) { |
| 117 | return; |
| 118 | } |
| 119 | |
| 120 | backend = g_new0(XenBackendInstance, 1); |
| 121 | backend->xenbus = xenbus; |
| 122 | backend->name = g_strdup(name); |
| 123 | |
Vladimir Sementsov-Ogievskiy | 1de7096 | 2020-07-07 18:50:37 +0200 | [diff] [blame] | 124 | impl->create(backend, opts, errp); |
| 125 | if (*errp) { |
Paul Durrant | a783f8a | 2019-01-08 14:49:00 +0000 | [diff] [blame] | 126 | g_free(backend->name); |
| 127 | g_free(backend); |
| 128 | return; |
| 129 | } |
| 130 | |
| 131 | backend->impl = impl; |
| 132 | xen_backend_list_add(backend); |
| 133 | } |
| 134 | |
| 135 | XenBus *xen_backend_get_bus(XenBackendInstance *backend) |
| 136 | { |
| 137 | return backend->xenbus; |
| 138 | } |
| 139 | |
| 140 | const char *xen_backend_get_name(XenBackendInstance *backend) |
| 141 | { |
| 142 | return backend->name; |
| 143 | } |
| 144 | |
| 145 | void xen_backend_set_device(XenBackendInstance *backend, |
| 146 | XenDevice *xendev) |
| 147 | { |
| 148 | g_assert(!backend->xendev); |
| 149 | backend->xendev = xendev; |
| 150 | } |
| 151 | |
| 152 | XenDevice *xen_backend_get_device(XenBackendInstance *backend) |
| 153 | { |
| 154 | return backend->xendev; |
| 155 | } |
| 156 | |
| 157 | |
| 158 | bool xen_backend_try_device_destroy(XenDevice *xendev, Error **errp) |
| 159 | { |
| 160 | XenBackendInstance *backend = xen_backend_list_find(xendev); |
| 161 | const XenBackendImpl *impl; |
| 162 | |
| 163 | if (!backend) { |
| 164 | return false; |
| 165 | } |
| 166 | |
| 167 | impl = backend->impl; |
| 168 | impl->destroy(backend, errp); |
| 169 | |
| 170 | xen_backend_list_remove(backend); |
| 171 | g_free(backend->name); |
| 172 | g_free(backend); |
| 173 | |
| 174 | return true; |
| 175 | } |