| 1 | #ifndef VHOST_H |
| 2 | #define VHOST_H |
| 3 | |
| 4 | #include "net/vhost_net.h" |
| 5 | #include "hw/virtio/vhost-backend.h" |
| 6 | #include "hw/virtio/virtio.h" |
| 7 | #include "system/memory.h" |
| 8 | |
| 9 | #define VHOST_F_DEVICE_IOTLB 63 |
| 10 | #define VHOST_USER_F_PROTOCOL_FEATURES 30 |
| 11 | |
| 12 | #define VU_REALIZE_CONN_RETRIES 3 |
| 13 | |
| 14 | /* Generic structures common for any vhost based device. */ |
| 15 | |
| 16 | struct vhost_inflight { |
| 17 | int fd; |
| 18 | void *addr; |
| 19 | uint64_t size; |
| 20 | uint64_t offset; |
| 21 | uint16_t queue_size; |
| 22 | }; |
| 23 | |
| 24 | struct vhost_virtqueue { |
| 25 | int kick; |
| 26 | int call; |
| 27 | void *desc_user; |
| 28 | void *avail_user; |
| 29 | void *used_user; |
| 30 | int num; |
| 31 | unsigned long long desc_phys; |
| 32 | unsigned desc_size; |
| 33 | unsigned long long avail_phys; |
| 34 | unsigned avail_size; |
| 35 | unsigned long long used_phys; |
| 36 | unsigned used_size; |
| 37 | EventNotifier masked_notifier; |
| 38 | EventNotifier error_notifier; |
| 39 | EventNotifier masked_config_notifier; |
| 40 | struct vhost_dev *dev; |
| 41 | }; |
| 42 | |
| 43 | typedef unsigned long vhost_log_chunk_t; |
| 44 | #define VHOST_LOG_PAGE 0x1000 |
| 45 | #define VHOST_LOG_BITS (8 * sizeof(vhost_log_chunk_t)) |
| 46 | #define VHOST_LOG_CHUNK (VHOST_LOG_PAGE * VHOST_LOG_BITS) |
| 47 | #define VHOST_INVALID_FEATURE_BIT (0xff) |
| 48 | #define VHOST_QUEUE_NUM_CONFIG_INR 0 |
| 49 | |
| 50 | struct vhost_log { |
| 51 | unsigned long long size; |
| 52 | int refcnt; |
| 53 | int fd; |
| 54 | vhost_log_chunk_t *log; |
| 55 | }; |
| 56 | |
| 57 | struct vhost_dev; |
| 58 | struct vhost_iommu { |
| 59 | struct vhost_dev *hdev; |
| 60 | MemoryRegion *mr; |
| 61 | hwaddr iommu_offset; |
| 62 | IOMMUNotifier n; |
| 63 | QLIST_ENTRY(vhost_iommu) iommu_next; |
| 64 | }; |
| 65 | |
| 66 | typedef struct VhostDevConfigOps { |
| 67 | /* Vhost device config space changed callback |
| 68 | */ |
| 69 | int (*vhost_dev_config_notifier)(struct vhost_dev *dev); |
| 70 | } VhostDevConfigOps; |
| 71 | |
| 72 | struct vhost_memory; |
| 73 | |
| 74 | /** |
| 75 | * struct vhost_dev - common vhost_dev structure |
| 76 | * @vhost_ops: backend specific ops |
| 77 | * @config_ops: ops for config changes (see @vhost_dev_set_config_notifier) |
| 78 | */ |
| 79 | struct vhost_dev { |
| 80 | VirtIODevice *vdev; |
| 81 | MemoryListener memory_listener; |
| 82 | MemoryListener iommu_listener; |
| 83 | struct vhost_memory *mem; |
| 84 | int n_mem_sections; |
| 85 | MemoryRegionSection *mem_sections; |
| 86 | int n_tmp_sections; |
| 87 | MemoryRegionSection *tmp_sections; |
| 88 | struct vhost_virtqueue *vqs; |
| 89 | unsigned int nvqs; |
| 90 | /* the first virtqueue which would be used by this vhost dev */ |
| 91 | int vq_index; |
| 92 | /* one past the last vq index for the virtio device (not vhost) */ |
| 93 | int vq_index_end; |
| 94 | /* if non-zero, minimum required value for max_queues */ |
| 95 | int num_queues; |
| 96 | /** |
| 97 | * vhost feature handling requires matching the feature set |
| 98 | * offered by a backend which may be a subset of the total |
| 99 | * features eventually offered to the guest. |
| 100 | * |
| 101 | * @_features: available features provided by the backend, private, |
| 102 | * direct access only in vhost.h/vhost.c |
| 103 | * @acked_features: final negotiated features with front-end driver |
| 104 | */ |
| 105 | VIRTIO_DECLARE_FEATURES(_features); |
| 106 | VIRTIO_DECLARE_FEATURES(acked_features); |
| 107 | |
| 108 | uint64_t max_queues; |
| 109 | uint64_t backend_cap; |
| 110 | /* @started: is the vhost device started? */ |
| 111 | bool started; |
| 112 | bool log_enabled; |
| 113 | uint64_t log_size; |
| 114 | Error *migration_blocker; |
| 115 | const VhostOps *vhost_ops; |
| 116 | void *opaque; |
| 117 | struct vhost_log *log; |
| 118 | QLIST_ENTRY(vhost_dev) entry; |
| 119 | QLIST_ENTRY(vhost_dev) logdev_entry; |
| 120 | QLIST_HEAD(, vhost_iommu) iommu_list; |
| 121 | IOMMUNotifier n; |
| 122 | const VhostDevConfigOps *config_ops; |
| 123 | }; |
| 124 | |
| 125 | extern const VhostOps kernel_ops; |
| 126 | extern const VhostOps user_ops; |
| 127 | extern const VhostOps vdpa_ops; |
| 128 | |
| 129 | struct vhost_net { |
| 130 | struct vhost_dev dev; |
| 131 | struct vhost_virtqueue vqs[2]; |
| 132 | int backend; |
| 133 | const int *feature_bits; |
| 134 | int max_tx_queue_size; |
| 135 | SaveAcketFeatures *save_acked_features; |
| 136 | bool is_vhost_user; |
| 137 | NetClientState *nc; |
| 138 | }; |
| 139 | |
| 140 | /** |
| 141 | * vhost_dev_init() - initialise the vhost interface |
| 142 | * @hdev: the common vhost_dev structure |
| 143 | * @opaque: opaque ptr passed to backend (vhost/vhost-user/vdpa) |
| 144 | * @backend_type: type of backend |
| 145 | * @busyloop_timeout: timeout for polling virtqueue |
| 146 | * @errp: error handle |
| 147 | * |
| 148 | * The initialisation of the vhost device will trigger the |
| 149 | * initialisation of the backend and potentially capability |
| 150 | * negotiation of backend interface. Configuration of the VirtIO |
| 151 | * itself won't happen until the interface is started. |
| 152 | * |
| 153 | * Return: 0 on success, non-zero on error while setting errp. |
| 154 | */ |
| 155 | int vhost_dev_init(struct vhost_dev *hdev, void *opaque, |
| 156 | VhostBackendType backend_type, |
| 157 | uint32_t busyloop_timeout, Error **errp); |
| 158 | |
| 159 | /** |
| 160 | * vhost_dev_cleanup() - tear down and cleanup vhost interface |
| 161 | * @hdev: the common vhost_dev structure |
| 162 | */ |
| 163 | void vhost_dev_cleanup(struct vhost_dev *hdev); |
| 164 | |
| 165 | void vhost_dev_disable_notifiers_nvqs(struct vhost_dev *hdev, |
| 166 | VirtIODevice *vdev, |
| 167 | unsigned int nvqs); |
| 168 | |
| 169 | /** |
| 170 | * vhost_dev_enable_notifiers() - enable event notifiers |
| 171 | * @hdev: common vhost_dev structure |
| 172 | * @vdev: the VirtIODevice structure |
| 173 | * |
| 174 | * Enable notifications directly to the vhost device rather than being |
| 175 | * triggered by QEMU itself. Notifications should be enabled before |
| 176 | * the vhost device is started via @vhost_dev_start. |
| 177 | * |
| 178 | * Return: 0 on success, < 0 on error. |
| 179 | */ |
| 180 | int vhost_dev_enable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev); |
| 181 | |
| 182 | /** |
| 183 | * vhost_dev_disable_notifiers - disable event notifications |
| 184 | * @hdev: common vhost_dev structure |
| 185 | * @vdev: the VirtIODevice structure |
| 186 | * |
| 187 | * Disable direct notifications to vhost device. |
| 188 | */ |
| 189 | void vhost_dev_disable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev); |
| 190 | bool vhost_config_pending(struct vhost_dev *hdev); |
| 191 | void vhost_config_mask(struct vhost_dev *hdev, VirtIODevice *vdev, bool mask); |
| 192 | |
| 193 | /** |
| 194 | * vhost_dev_is_started() - report status of vhost device |
| 195 | * @hdev: common vhost_dev structure |
| 196 | * |
| 197 | * Return the started status of the vhost device |
| 198 | */ |
| 199 | static inline bool vhost_dev_is_started(struct vhost_dev *hdev) |
| 200 | { |
| 201 | return hdev->started; |
| 202 | } |
| 203 | |
| 204 | static inline int vhost_dev_set_vring_enable(struct vhost_dev *hdev, int enable) |
| 205 | { |
| 206 | if (!hdev->vhost_ops->vhost_set_vring_enable) { |
| 207 | return 0; |
| 208 | } |
| 209 | |
| 210 | return hdev->vhost_ops->vhost_set_vring_enable(hdev, enable); |
| 211 | } |
| 212 | |
| 213 | /** |
| 214 | * vhost_dev_start() - start the vhost device |
| 215 | * @hdev: common vhost_dev structure |
| 216 | * @vdev: the VirtIODevice structure |
| 217 | * @vrings: true to have vrings enabled in this call |
| 218 | * |
| 219 | * Starts the vhost device. From this point VirtIO feature negotiation |
| 220 | * can start and the device can start processing VirtIO transactions. |
| 221 | * |
| 222 | * Return: 0 on success, < 0 on error. |
| 223 | */ |
| 224 | int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev, bool vrings); |
| 225 | |
| 226 | /** |
| 227 | * vhost_dev_stop() - stop the vhost device |
| 228 | * @hdev: common vhost_dev structure |
| 229 | * @vdev: the VirtIODevice structure |
| 230 | * @vrings: true to have vrings disabled in this call |
| 231 | * |
| 232 | * Stop the vhost device. After the device is stopped the notifiers |
| 233 | * can be disabled (@vhost_dev_disable_notifiers) and the device can |
| 234 | * be torn down (@vhost_dev_cleanup). |
| 235 | * |
| 236 | * Return: 0 on success, != 0 on error when stopping dev. |
| 237 | */ |
| 238 | int vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev, bool vrings); |
| 239 | |
| 240 | /** |
| 241 | * vhost_dev_force_stop() - force stop the vhost device |
| 242 | * @hdev: common vhost_dev structure |
| 243 | * @vdev: the VirtIODevice structure |
| 244 | * @vrings: true to have vrings disabled in this call |
| 245 | * |
| 246 | * Force stop the vhost device. After the device is stopped the notifiers |
| 247 | * can be disabled (@vhost_dev_disable_notifiers) and the device can |
| 248 | * be torn down (@vhost_dev_cleanup). Unlike @vhost_dev_stop, this doesn't |
| 249 | * attempt to flush in-flight backend requests by skipping GET_VRING_BASE |
| 250 | * entirely. |
| 251 | */ |
| 252 | int vhost_dev_force_stop(struct vhost_dev *hdev, VirtIODevice *vdev, |
| 253 | bool vrings); |
| 254 | |
| 255 | /** |
| 256 | * DOC: vhost device configuration handling |
| 257 | * |
| 258 | * The VirtIO device configuration space is used for rarely changing |
| 259 | * or initialisation time parameters. The configuration can be updated |
| 260 | * by either the guest driver or the device itself. If the device can |
| 261 | * change the configuration over time the vhost handler should |
| 262 | * register a @VhostDevConfigOps structure with |
| 263 | * @vhost_dev_set_config_notifier so the guest can be notified. Some |
| 264 | * devices register a handler anyway and will signal an error if an |
| 265 | * unexpected config change happens. |
| 266 | */ |
| 267 | |
| 268 | /** |
| 269 | * vhost_dev_get_config() - fetch device configuration |
| 270 | * @hdev: common vhost_dev_structure |
| 271 | * @config: pointer to device appropriate config structure |
| 272 | * @config_len: size of device appropriate config structure |
| 273 | * |
| 274 | * Return: 0 on success, < 0 on error while setting errp |
| 275 | */ |
| 276 | int vhost_dev_get_config(struct vhost_dev *hdev, uint8_t *config, |
| 277 | uint32_t config_len, Error **errp); |
| 278 | |
| 279 | /** |
| 280 | * vhost_dev_set_config() - set device configuration |
| 281 | * @hdev: common vhost_dev_structure |
| 282 | * @data: pointer to data to set |
| 283 | * @offset: offset into configuration space |
| 284 | * @size: length of set |
| 285 | * @flags: @VhostSetConfigType flags |
| 286 | * |
| 287 | * By use of @offset/@size a subset of the configuration space can be |
| 288 | * written to. The @flags are used to indicate if it is a normal |
| 289 | * transaction or related to migration. |
| 290 | * |
| 291 | * Return: 0 on success, non-zero on error |
| 292 | */ |
| 293 | int vhost_dev_set_config(struct vhost_dev *dev, const uint8_t *data, |
| 294 | uint32_t offset, uint32_t size, uint32_t flags); |
| 295 | |
| 296 | /** |
| 297 | * vhost_dev_set_config_notifier() - register VhostDevConfigOps |
| 298 | * @hdev: common vhost_dev_structure |
| 299 | * @ops: notifier ops |
| 300 | * |
| 301 | * If the device is expected to change configuration a notifier can be |
| 302 | * setup to handle the case. |
| 303 | */ |
| 304 | void vhost_dev_set_config_notifier(struct vhost_dev *dev, |
| 305 | const VhostDevConfigOps *ops); |
| 306 | |
| 307 | |
| 308 | /* Test and clear masked event pending status. |
| 309 | * Should be called after unmask to avoid losing events. |
| 310 | */ |
| 311 | bool vhost_virtqueue_pending(struct vhost_dev *hdev, int n); |
| 312 | |
| 313 | /* Mask/unmask events from this vq. |
| 314 | */ |
| 315 | void vhost_virtqueue_mask(struct vhost_dev *hdev, VirtIODevice *vdev, int n, |
| 316 | bool mask); |
| 317 | |
| 318 | /** |
| 319 | * vhost_get_features_ex() - sanitize the extended features set |
| 320 | * @hdev: common vhost_dev structure |
| 321 | * @feature_bits: pointer to terminated table of feature bits |
| 322 | * @features: original features set, filtered out on return |
| 323 | * |
| 324 | * This is the extended variant of vhost_get_features(), supporting the |
| 325 | * the extended features set. Filter it with the intersection of what is |
| 326 | * supported by the vhost backend (hdev->features) and the supported |
| 327 | * feature_bits. |
| 328 | */ |
| 329 | void vhost_get_features_ex(struct vhost_dev *hdev, |
| 330 | const int *feature_bits, |
| 331 | uint64_t *features); |
| 332 | /** |
| 333 | * vhost_get_features() - return a sanitised set of feature bits |
| 334 | * @hdev: common vhost_dev structure |
| 335 | * @feature_bits: pointer to terminated table of feature bits |
| 336 | * @features: original feature set |
| 337 | * |
| 338 | * This returns a set of features bits that is an intersection of what |
| 339 | * is supported by the vhost backend (hdev->features), the supported |
| 340 | * feature_bits and the requested feature set. |
| 341 | */ |
| 342 | static inline uint64_t vhost_get_features(struct vhost_dev *hdev, |
| 343 | const int *feature_bits, |
| 344 | uint64_t features) |
| 345 | { |
| 346 | uint64_t features_ex[VIRTIO_FEATURES_NU64S]; |
| 347 | |
| 348 | virtio_features_from_u64(features_ex, features); |
| 349 | vhost_get_features_ex(hdev, feature_bits, features_ex); |
| 350 | return features_ex[0]; |
| 351 | } |
| 352 | |
| 353 | /** |
| 354 | * vhost_ack_features_ex() - set vhost full set of acked_features |
| 355 | * @hdev: common vhost_dev structure |
| 356 | * @feature_bits: pointer to terminated table of feature bits |
| 357 | * @features: requested feature set |
| 358 | * |
| 359 | * This sets the internal hdev->acked_features to the intersection of |
| 360 | * the backends advertised features and the supported feature_bits. |
| 361 | */ |
| 362 | void vhost_ack_features_ex(struct vhost_dev *hdev, const int *feature_bits, |
| 363 | const uint64_t *features); |
| 364 | |
| 365 | /** |
| 366 | * vhost_ack_features() - set vhost acked_features |
| 367 | * @hdev: common vhost_dev structure |
| 368 | * @feature_bits: pointer to terminated table of feature bits |
| 369 | * @features: requested feature set |
| 370 | * |
| 371 | * This sets the internal hdev->acked_features to the intersection of |
| 372 | * the backends advertised features and the supported feature_bits. |
| 373 | */ |
| 374 | static inline void vhost_ack_features(struct vhost_dev *hdev, |
| 375 | const int *feature_bits, |
| 376 | uint64_t features) |
| 377 | { |
| 378 | uint64_t features_ex[VIRTIO_FEATURES_NU64S]; |
| 379 | |
| 380 | virtio_features_from_u64(features_ex, features); |
| 381 | vhost_ack_features_ex(hdev, feature_bits, features_ex); |
| 382 | } |
| 383 | |
| 384 | unsigned int vhost_get_max_memslots(void); |
| 385 | unsigned int vhost_get_free_memslots(void); |
| 386 | |
| 387 | int vhost_net_set_backend(struct vhost_dev *hdev, |
| 388 | struct vhost_vring_file *file); |
| 389 | |
| 390 | void vhost_toggle_device_iotlb(VirtIODevice *vdev); |
| 391 | int vhost_device_iotlb_miss(struct vhost_dev *dev, uint64_t iova, int write); |
| 392 | |
| 393 | int vhost_virtqueue_start(struct vhost_dev *dev, struct VirtIODevice *vdev, |
| 394 | struct vhost_virtqueue *vq, unsigned idx); |
| 395 | int vhost_virtqueue_stop(struct vhost_dev *dev, struct VirtIODevice *vdev, |
| 396 | struct vhost_virtqueue *vq, unsigned idx); |
| 397 | |
| 398 | void vhost_dev_reset_inflight(struct vhost_inflight *inflight); |
| 399 | void vhost_dev_free_inflight(struct vhost_inflight *inflight); |
| 400 | int vhost_dev_prepare_inflight(struct vhost_dev *hdev, VirtIODevice *vdev); |
| 401 | int vhost_dev_set_inflight(struct vhost_dev *dev, |
| 402 | struct vhost_inflight *inflight); |
| 403 | int vhost_dev_get_inflight(struct vhost_dev *dev, uint16_t queue_size, |
| 404 | struct vhost_inflight *inflight); |
| 405 | bool vhost_dev_has_iommu(struct vhost_dev *dev); |
| 406 | int vhost_handle_iotlb_msg(struct vhost_dev *dev, struct vhost_iotlb_msg *imsg); |
| 407 | |
| 408 | |
| 409 | static inline bool vhost_dev_has_feature(struct vhost_dev *dev, |
| 410 | uint64_t feature) |
| 411 | { |
| 412 | return virtio_has_feature(dev->_features, feature); |
| 413 | } |
| 414 | |
| 415 | static inline bool vhost_dev_has_feature_ex(struct vhost_dev *dev, |
| 416 | uint64_t feature) |
| 417 | { |
| 418 | return virtio_has_feature_ex(dev->_features_ex, feature); |
| 419 | } |
| 420 | |
| 421 | static inline uint64_t vhost_dev_features(struct vhost_dev *dev) |
| 422 | { |
| 423 | return dev->_features; |
| 424 | } |
| 425 | |
| 426 | static inline const uint64_t *vhost_dev_features_ex(struct vhost_dev *dev) |
| 427 | { |
| 428 | return dev->_features_ex; |
| 429 | } |
| 430 | |
| 431 | static inline void vhost_dev_clear_feature(struct vhost_dev *dev, |
| 432 | uint64_t feature) |
| 433 | { |
| 434 | virtio_clear_feature(&dev->_features, feature); |
| 435 | } |
| 436 | |
| 437 | static inline void vhost_dev_clear_feature_ex(struct vhost_dev *dev, |
| 438 | uint64_t feature) |
| 439 | { |
| 440 | virtio_clear_feature_ex(dev->_features_ex, feature); |
| 441 | } |
| 442 | |
| 443 | #ifdef CONFIG_VHOST |
| 444 | int vhost_reset_device(struct vhost_dev *hdev); |
| 445 | #else |
| 446 | static inline int vhost_reset_device(struct vhost_dev *hdev) |
| 447 | { |
| 448 | return -ENOSYS; |
| 449 | } |
| 450 | #endif /* CONFIG_VHOST */ |
| 451 | |
| 452 | /** |
| 453 | * vhost_supports_device_state(): Checks whether the back-end supports |
| 454 | * transferring internal device state for the purpose of migration. |
| 455 | * Support for this feature is required for vhost_set_device_state_fd() |
| 456 | * and vhost_check_device_state(). |
| 457 | * |
| 458 | * @dev: The vhost device |
| 459 | * |
| 460 | * Returns true if the device supports these commands, and false if it |
| 461 | * does not. |
| 462 | */ |
| 463 | #ifdef CONFIG_VHOST |
| 464 | bool vhost_supports_device_state(struct vhost_dev *dev); |
| 465 | #else |
| 466 | static inline bool vhost_supports_device_state(struct vhost_dev *dev) |
| 467 | { |
| 468 | return false; |
| 469 | } |
| 470 | #endif |
| 471 | |
| 472 | /** |
| 473 | * vhost_set_device_state_fd(): Begin transfer of internal state from/to |
| 474 | * the back-end for the purpose of migration. Data is to be transferred |
| 475 | * over a pipe according to @direction and @phase. The sending end must |
| 476 | * only write to the pipe, and the receiving end must only read from it. |
| 477 | * Once the sending end is done, it closes its FD. The receiving end |
| 478 | * must take this as the end-of-transfer signal and close its FD, too. |
| 479 | * |
| 480 | * @fd is the back-end's end of the pipe: The write FD for SAVE, and the |
| 481 | * read FD for LOAD. This function transfers ownership of @fd to the |
| 482 | * back-end, i.e. closes it in the front-end. |
| 483 | * |
| 484 | * The back-end may optionally reply with an FD of its own, if this |
| 485 | * improves efficiency on its end. In this case, the returned FD is |
| 486 | * stored in *reply_fd. The back-end will discard the FD sent to it, |
| 487 | * and the front-end must use *reply_fd for transferring state to/from |
| 488 | * the back-end. |
| 489 | * |
| 490 | * @dev: The vhost device |
| 491 | * @direction: The direction in which the state is to be transferred. |
| 492 | * For outgoing migrations, this is SAVE, and data is read |
| 493 | * from the back-end and stored by the front-end in the |
| 494 | * migration stream. |
| 495 | * For incoming migrations, this is LOAD, and data is read |
| 496 | * by the front-end from the migration stream and sent to |
| 497 | * the back-end to restore the saved state. |
| 498 | * @phase: Which migration phase we are in. Currently, there is only |
| 499 | * STOPPED (device and all vrings are stopped), in the future, |
| 500 | * more phases such as PRE_COPY or POST_COPY may be added. |
| 501 | * @fd: Back-end's end of the pipe through which to transfer state; note |
| 502 | * that ownership is transferred to the back-end, so this function |
| 503 | * closes @fd in the front-end. |
| 504 | * @reply_fd: If the back-end wishes to use a different pipe for state |
| 505 | * transfer, this will contain an FD for the front-end to |
| 506 | * use. Otherwise, -1 is stored here. |
| 507 | * @errp: Potential error description |
| 508 | * |
| 509 | * Returns 0 on success, and -errno on failure. |
| 510 | */ |
| 511 | int vhost_set_device_state_fd(struct vhost_dev *dev, |
| 512 | VhostDeviceStateDirection direction, |
| 513 | VhostDeviceStatePhase phase, |
| 514 | int fd, |
| 515 | int *reply_fd, |
| 516 | Error **errp); |
| 517 | |
| 518 | /** |
| 519 | * vhost_set_device_state_fd(): After transferring state from/to the |
| 520 | * back-end via vhost_set_device_state_fd(), i.e. once the sending end |
| 521 | * has closed the pipe, inquire the back-end to report any potential |
| 522 | * errors that have occurred on its side. This allows to sense errors |
| 523 | * like: |
| 524 | * - During outgoing migration, when the source side had already started |
| 525 | * to produce its state, something went wrong and it failed to finish |
| 526 | * - During incoming migration, when the received state is somehow |
| 527 | * invalid and cannot be processed by the back-end |
| 528 | * |
| 529 | * @dev: The vhost device |
| 530 | * @errp: Potential error description |
| 531 | * |
| 532 | * Returns 0 when the back-end reports successful state transfer and |
| 533 | * processing, and -errno when an error occurred somewhere. |
| 534 | */ |
| 535 | int vhost_check_device_state(struct vhost_dev *dev, Error **errp); |
| 536 | |
| 537 | /** |
| 538 | * vhost_save_backend_state(): High-level function to receive a vhost |
| 539 | * back-end's state, and save it in @f. Uses |
| 540 | * `vhost_set_device_state_fd()` to get the data from the back-end, and |
| 541 | * stores it in consecutive chunks that are each prefixed by their |
| 542 | * respective length (be32). The end is marked by a 0-length chunk. |
| 543 | * |
| 544 | * Must only be called while the device and all its vrings are stopped |
| 545 | * (`VHOST_TRANSFER_STATE_PHASE_STOPPED`). |
| 546 | * |
| 547 | * @dev: The vhost device from which to save the state |
| 548 | * @f: Migration stream in which to save the state |
| 549 | * @errp: Potential error message |
| 550 | * |
| 551 | * Returns 0 on success, and -errno otherwise. |
| 552 | */ |
| 553 | #ifdef CONFIG_VHOST |
| 554 | int vhost_save_backend_state(struct vhost_dev *dev, QEMUFile *f, Error **errp); |
| 555 | #else |
| 556 | static inline int vhost_save_backend_state(struct vhost_dev *dev, QEMUFile *f, |
| 557 | Error **errp) |
| 558 | { |
| 559 | return -ENOSYS; |
| 560 | } |
| 561 | #endif |
| 562 | |
| 563 | /** |
| 564 | * vhost_load_backend_state(): High-level function to load a vhost |
| 565 | * back-end's state from @f, and send it over to the back-end. Reads |
| 566 | * the data from @f in the format used by `vhost_save_state()`, and uses |
| 567 | * `vhost_set_device_state_fd()` to transfer it to the back-end. |
| 568 | * |
| 569 | * Must only be called while the device and all its vrings are stopped |
| 570 | * (`VHOST_TRANSFER_STATE_PHASE_STOPPED`). |
| 571 | * |
| 572 | * @dev: The vhost device to which to send the state |
| 573 | * @f: Migration stream from which to load the state |
| 574 | * @errp: Potential error message |
| 575 | * |
| 576 | * Returns 0 on success, and -errno otherwise. |
| 577 | */ |
| 578 | #ifdef CONFIG_VHOST |
| 579 | int vhost_load_backend_state(struct vhost_dev *dev, QEMUFile *f, Error **errp); |
| 580 | #else |
| 581 | static inline int vhost_load_backend_state(struct vhost_dev *dev, QEMUFile *f, |
| 582 | Error **errp) |
| 583 | { |
| 584 | return -ENOSYS; |
| 585 | } |
| 586 | #endif |
| 587 | |
| 588 | extern const VMStateDescription vmstate_vhost_inflight_region; |
| 589 | #define VMSTATE_VHOST_INFLIGHT_REGION(_field, _state) \ |
| 590 | VMSTATE_STRUCT_POINTER(_field, _state, \ |
| 591 | vmstate_vhost_inflight_region, \ |
| 592 | struct vhost_inflight) |
| 593 | |
| 594 | #endif |