1 /* 2 * Vhost-user filesystem virtio device 3 * 4 * Copyright 2018-2019 Red Hat, Inc. 5 * 6 * Authors: 7 * Stefan Hajnoczi <stefanha@redhat.com> 8 * 9 * This work is licensed under the terms of the GNU GPL, version 2 or 10 * (at your option) any later version. See the COPYING file in the 11 * top-level directory. 12 */ 13 14 #include "qemu/osdep.h" 15 #include <sys/ioctl.h> 16 #include "standard-headers/linux/virtio_fs.h" 17 #include "qapi/error.h" 18 #include "hw/qdev-properties.h" 19 #include "hw/qdev-properties-system.h" 20 #include "hw/virtio/virtio-bus.h" 21 #include "hw/virtio/virtio-access.h" 22 #include "qemu/error-report.h" 23 #include "hw/virtio/vhost-user-fs.h" 24 #include "monitor/monitor.h" 25 #include "sysemu/sysemu.h" 26 27 static const int user_feature_bits[] = { 28 VIRTIO_F_VERSION_1, 29 VIRTIO_RING_F_INDIRECT_DESC, 30 VIRTIO_RING_F_EVENT_IDX, 31 VIRTIO_F_NOTIFY_ON_EMPTY, 32 VIRTIO_F_RING_PACKED, 33 VIRTIO_F_IOMMU_PLATFORM, 34 35 VHOST_INVALID_FEATURE_BIT 36 }; 37 38 static void vuf_get_config(VirtIODevice *vdev, uint8_t *config) 39 { 40 VHostUserFS *fs = VHOST_USER_FS(vdev); 41 struct virtio_fs_config fscfg = {}; 42 43 memcpy((char *)fscfg.tag, fs->conf.tag, 44 MIN(strlen(fs->conf.tag) + 1, sizeof(fscfg.tag))); 45 46 virtio_stl_p(vdev, &fscfg.num_request_queues, fs->conf.num_request_queues); 47 48 memcpy(config, &fscfg, sizeof(fscfg)); 49 } 50 51 static void vuf_start(VirtIODevice *vdev) 52 { 53 VHostUserFS *fs = VHOST_USER_FS(vdev); 54 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); 55 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 56 int ret; 57 int i; 58 59 if (!k->set_guest_notifiers) { 60 error_report("binding does not support guest notifiers"); 61 return; 62 } 63 64 ret = vhost_dev_enable_notifiers(&fs->vhost_dev, vdev); 65 if (ret < 0) { 66 error_report("Error enabling host notifiers: %d", -ret); 67 return; 68 } 69 70 ret = k->set_guest_notifiers(qbus->parent, fs->vhost_dev.nvqs, true); 71 if (ret < 0) { 72 error_report("Error binding guest notifier: %d", -ret); 73 goto err_host_notifiers; 74 } 75 76 fs->vhost_dev.acked_features = vdev->guest_features; 77 ret = vhost_dev_start(&fs->vhost_dev, vdev); 78 if (ret < 0) { 79 error_report("Error starting vhost: %d", -ret); 80 goto err_guest_notifiers; 81 } 82 83 /* 84 * guest_notifier_mask/pending not used yet, so just unmask 85 * everything here. virtio-pci will do the right thing by 86 * enabling/disabling irqfd. 87 */ 88 for (i = 0; i < fs->vhost_dev.nvqs; i++) { 89 vhost_virtqueue_mask(&fs->vhost_dev, vdev, i, false); 90 } 91 92 return; 93 94 err_guest_notifiers: 95 k->set_guest_notifiers(qbus->parent, fs->vhost_dev.nvqs, false); 96 err_host_notifiers: 97 vhost_dev_disable_notifiers(&fs->vhost_dev, vdev); 98 } 99 100 static void vuf_stop(VirtIODevice *vdev) 101 { 102 VHostUserFS *fs = VHOST_USER_FS(vdev); 103 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); 104 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 105 int ret; 106 107 if (!k->set_guest_notifiers) { 108 return; 109 } 110 111 vhost_dev_stop(&fs->vhost_dev, vdev); 112 113 ret = k->set_guest_notifiers(qbus->parent, fs->vhost_dev.nvqs, false); 114 if (ret < 0) { 115 error_report("vhost guest notifier cleanup failed: %d", ret); 116 return; 117 } 118 119 vhost_dev_disable_notifiers(&fs->vhost_dev, vdev); 120 } 121 122 static void vuf_set_status(VirtIODevice *vdev, uint8_t status) 123 { 124 VHostUserFS *fs = VHOST_USER_FS(vdev); 125 bool should_start = status & VIRTIO_CONFIG_S_DRIVER_OK; 126 127 if (!vdev->vm_running) { 128 should_start = false; 129 } 130 131 if (fs->vhost_dev.started == should_start) { 132 return; 133 } 134 135 if (should_start) { 136 vuf_start(vdev); 137 } else { 138 vuf_stop(vdev); 139 } 140 } 141 142 static uint64_t vuf_get_features(VirtIODevice *vdev, 143 uint64_t features, 144 Error **errp) 145 { 146 VHostUserFS *fs = VHOST_USER_FS(vdev); 147 148 return vhost_get_features(&fs->vhost_dev, user_feature_bits, features); 149 } 150 151 static void vuf_handle_output(VirtIODevice *vdev, VirtQueue *vq) 152 { 153 /* 154 * Not normally called; it's the daemon that handles the queue; 155 * however virtio's cleanup path can call this. 156 */ 157 } 158 159 static void vuf_guest_notifier_mask(VirtIODevice *vdev, int idx, 160 bool mask) 161 { 162 VHostUserFS *fs = VHOST_USER_FS(vdev); 163 164 vhost_virtqueue_mask(&fs->vhost_dev, vdev, idx, mask); 165 } 166 167 static bool vuf_guest_notifier_pending(VirtIODevice *vdev, int idx) 168 { 169 VHostUserFS *fs = VHOST_USER_FS(vdev); 170 171 return vhost_virtqueue_pending(&fs->vhost_dev, idx); 172 } 173 174 static void vuf_device_realize(DeviceState *dev, Error **errp) 175 { 176 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 177 VHostUserFS *fs = VHOST_USER_FS(dev); 178 unsigned int i; 179 size_t len; 180 int ret; 181 182 if (!fs->conf.chardev.chr) { 183 error_setg(errp, "missing chardev"); 184 return; 185 } 186 187 if (!fs->conf.tag) { 188 error_setg(errp, "missing tag property"); 189 return; 190 } 191 len = strlen(fs->conf.tag); 192 if (len == 0) { 193 error_setg(errp, "tag property cannot be empty"); 194 return; 195 } 196 if (len > sizeof_field(struct virtio_fs_config, tag)) { 197 error_setg(errp, "tag property must be %zu bytes or less", 198 sizeof_field(struct virtio_fs_config, tag)); 199 return; 200 } 201 202 if (fs->conf.num_request_queues == 0) { 203 error_setg(errp, "num-request-queues property must be larger than 0"); 204 return; 205 } 206 207 if (!is_power_of_2(fs->conf.queue_size)) { 208 error_setg(errp, "queue-size property must be a power of 2"); 209 return; 210 } 211 212 if (fs->conf.queue_size > VIRTQUEUE_MAX_SIZE) { 213 error_setg(errp, "queue-size property must be %u or smaller", 214 VIRTQUEUE_MAX_SIZE); 215 return; 216 } 217 218 if (!vhost_user_init(&fs->vhost_user, &fs->conf.chardev, errp)) { 219 return; 220 } 221 222 virtio_init(vdev, VIRTIO_ID_FS, sizeof(struct virtio_fs_config)); 223 224 /* Hiprio queue */ 225 fs->hiprio_vq = virtio_add_queue(vdev, fs->conf.queue_size, vuf_handle_output); 226 227 /* Request queues */ 228 fs->req_vqs = g_new(VirtQueue *, fs->conf.num_request_queues); 229 for (i = 0; i < fs->conf.num_request_queues; i++) { 230 fs->req_vqs[i] = virtio_add_queue(vdev, fs->conf.queue_size, vuf_handle_output); 231 } 232 233 /* 1 high prio queue, plus the number configured */ 234 fs->vhost_dev.nvqs = 1 + fs->conf.num_request_queues; 235 fs->vhost_dev.vqs = g_new0(struct vhost_virtqueue, fs->vhost_dev.nvqs); 236 ret = vhost_dev_init(&fs->vhost_dev, &fs->vhost_user, 237 VHOST_BACKEND_TYPE_USER, 0, errp); 238 if (ret < 0) { 239 goto err_virtio; 240 } 241 242 return; 243 244 err_virtio: 245 vhost_user_cleanup(&fs->vhost_user); 246 virtio_delete_queue(fs->hiprio_vq); 247 for (i = 0; i < fs->conf.num_request_queues; i++) { 248 virtio_delete_queue(fs->req_vqs[i]); 249 } 250 g_free(fs->req_vqs); 251 virtio_cleanup(vdev); 252 g_free(fs->vhost_dev.vqs); 253 return; 254 } 255 256 static void vuf_device_unrealize(DeviceState *dev) 257 { 258 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 259 VHostUserFS *fs = VHOST_USER_FS(dev); 260 int i; 261 262 /* This will stop vhost backend if appropriate. */ 263 vuf_set_status(vdev, 0); 264 265 vhost_dev_cleanup(&fs->vhost_dev); 266 267 vhost_user_cleanup(&fs->vhost_user); 268 269 virtio_delete_queue(fs->hiprio_vq); 270 for (i = 0; i < fs->conf.num_request_queues; i++) { 271 virtio_delete_queue(fs->req_vqs[i]); 272 } 273 g_free(fs->req_vqs); 274 virtio_cleanup(vdev); 275 g_free(fs->vhost_dev.vqs); 276 fs->vhost_dev.vqs = NULL; 277 } 278 279 static struct vhost_dev *vuf_get_vhost(VirtIODevice *vdev) 280 { 281 VHostUserFS *fs = VHOST_USER_FS(vdev); 282 return &fs->vhost_dev; 283 } 284 285 static const VMStateDescription vuf_vmstate = { 286 .name = "vhost-user-fs", 287 .unmigratable = 1, 288 }; 289 290 static Property vuf_properties[] = { 291 DEFINE_PROP_CHR("chardev", VHostUserFS, conf.chardev), 292 DEFINE_PROP_STRING("tag", VHostUserFS, conf.tag), 293 DEFINE_PROP_UINT16("num-request-queues", VHostUserFS, 294 conf.num_request_queues, 1), 295 DEFINE_PROP_UINT16("queue-size", VHostUserFS, conf.queue_size, 128), 296 DEFINE_PROP_END_OF_LIST(), 297 }; 298 299 static void vuf_instance_init(Object *obj) 300 { 301 VHostUserFS *fs = VHOST_USER_FS(obj); 302 303 device_add_bootindex_property(obj, &fs->bootindex, "bootindex", 304 "/filesystem@0", DEVICE(obj)); 305 } 306 307 static void vuf_class_init(ObjectClass *klass, void *data) 308 { 309 DeviceClass *dc = DEVICE_CLASS(klass); 310 VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass); 311 312 device_class_set_props(dc, vuf_properties); 313 dc->vmsd = &vuf_vmstate; 314 set_bit(DEVICE_CATEGORY_STORAGE, dc->categories); 315 vdc->realize = vuf_device_realize; 316 vdc->unrealize = vuf_device_unrealize; 317 vdc->get_features = vuf_get_features; 318 vdc->get_config = vuf_get_config; 319 vdc->set_status = vuf_set_status; 320 vdc->guest_notifier_mask = vuf_guest_notifier_mask; 321 vdc->guest_notifier_pending = vuf_guest_notifier_pending; 322 vdc->get_vhost = vuf_get_vhost; 323 } 324 325 static const TypeInfo vuf_info = { 326 .name = TYPE_VHOST_USER_FS, 327 .parent = TYPE_VIRTIO_DEVICE, 328 .instance_size = sizeof(VHostUserFS), 329 .instance_init = vuf_instance_init, 330 .class_init = vuf_class_init, 331 }; 332 333 static void vuf_register_types(void) 334 { 335 type_register_static(&vuf_info); 336 } 337 338 type_init(vuf_register_types) 339