1 /* 2 * Migration support for VFIO devices 3 * 4 * Copyright NVIDIA, Inc. 2020 5 * 6 * This work is licensed under the terms of the GNU GPL, version 2. See 7 * the COPYING file in the top-level directory. 8 */ 9 10 #include "qemu/osdep.h" 11 #include "qemu/main-loop.h" 12 #include "qemu/cutils.h" 13 #include "qemu/units.h" 14 #include "qemu/error-report.h" 15 #include <linux/vfio.h> 16 #include <sys/ioctl.h> 17 18 #include "sysemu/runstate.h" 19 #include "hw/vfio/vfio-common.h" 20 #include "migration/misc.h" 21 #include "migration/savevm.h" 22 #include "migration/vmstate.h" 23 #include "migration/qemu-file.h" 24 #include "migration/register.h" 25 #include "migration/blocker.h" 26 #include "qapi/error.h" 27 #include "qapi/qapi-events-vfio.h" 28 #include "exec/ramlist.h" 29 #include "exec/ram_addr.h" 30 #include "pci.h" 31 #include "trace.h" 32 #include "hw/hw.h" 33 34 /* 35 * Flags to be used as unique delimiters for VFIO devices in the migration 36 * stream. These flags are composed as: 37 * 0xffffffff => MSB 32-bit all 1s 38 * 0xef10 => Magic ID, represents emulated (virtual) function IO 39 * 0x0000 => 16-bits reserved for flags 40 * 41 * The beginning of state information is marked by _DEV_CONFIG_STATE, 42 * _DEV_SETUP_STATE, or _DEV_DATA_STATE, respectively. The end of a 43 * certain state information is marked by _END_OF_STATE. 44 */ 45 #define VFIO_MIG_FLAG_END_OF_STATE (0xffffffffef100001ULL) 46 #define VFIO_MIG_FLAG_DEV_CONFIG_STATE (0xffffffffef100002ULL) 47 #define VFIO_MIG_FLAG_DEV_SETUP_STATE (0xffffffffef100003ULL) 48 #define VFIO_MIG_FLAG_DEV_DATA_STATE (0xffffffffef100004ULL) 49 #define VFIO_MIG_FLAG_DEV_INIT_DATA_SENT (0xffffffffef100005ULL) 50 51 /* 52 * This is an arbitrary size based on migration of mlx5 devices, where typically 53 * total device migration size is on the order of 100s of MB. Testing with 54 * larger values, e.g. 128MB and 1GB, did not show a performance improvement. 55 */ 56 #define VFIO_MIG_DEFAULT_DATA_BUFFER_SIZE (1 * MiB) 57 58 static int64_t bytes_transferred; 59 60 static const char *mig_state_to_str(enum vfio_device_mig_state state) 61 { 62 switch (state) { 63 case VFIO_DEVICE_STATE_ERROR: 64 return "ERROR"; 65 case VFIO_DEVICE_STATE_STOP: 66 return "STOP"; 67 case VFIO_DEVICE_STATE_RUNNING: 68 return "RUNNING"; 69 case VFIO_DEVICE_STATE_STOP_COPY: 70 return "STOP_COPY"; 71 case VFIO_DEVICE_STATE_RESUMING: 72 return "RESUMING"; 73 case VFIO_DEVICE_STATE_RUNNING_P2P: 74 return "RUNNING_P2P"; 75 case VFIO_DEVICE_STATE_PRE_COPY: 76 return "PRE_COPY"; 77 case VFIO_DEVICE_STATE_PRE_COPY_P2P: 78 return "PRE_COPY_P2P"; 79 default: 80 return "UNKNOWN STATE"; 81 } 82 } 83 84 static VfioMigrationState 85 mig_state_to_qapi_state(enum vfio_device_mig_state state) 86 { 87 switch (state) { 88 case VFIO_DEVICE_STATE_STOP: 89 return QAPI_VFIO_MIGRATION_STATE_STOP; 90 case VFIO_DEVICE_STATE_RUNNING: 91 return QAPI_VFIO_MIGRATION_STATE_RUNNING; 92 case VFIO_DEVICE_STATE_STOP_COPY: 93 return QAPI_VFIO_MIGRATION_STATE_STOP_COPY; 94 case VFIO_DEVICE_STATE_RESUMING: 95 return QAPI_VFIO_MIGRATION_STATE_RESUMING; 96 case VFIO_DEVICE_STATE_RUNNING_P2P: 97 return QAPI_VFIO_MIGRATION_STATE_RUNNING_P2P; 98 case VFIO_DEVICE_STATE_PRE_COPY: 99 return QAPI_VFIO_MIGRATION_STATE_PRE_COPY; 100 case VFIO_DEVICE_STATE_PRE_COPY_P2P: 101 return QAPI_VFIO_MIGRATION_STATE_PRE_COPY_P2P; 102 default: 103 g_assert_not_reached(); 104 } 105 } 106 107 static void vfio_migration_send_event(VFIODevice *vbasedev) 108 { 109 VFIOMigration *migration = vbasedev->migration; 110 DeviceState *dev = vbasedev->dev; 111 g_autofree char *qom_path = NULL; 112 Object *obj; 113 114 if (!vbasedev->migration_events) { 115 return; 116 } 117 118 g_assert(vbasedev->ops->vfio_get_object); 119 obj = vbasedev->ops->vfio_get_object(vbasedev); 120 g_assert(obj); 121 qom_path = object_get_canonical_path(obj); 122 123 qapi_event_send_vfio_migration( 124 dev->id, qom_path, mig_state_to_qapi_state(migration->device_state)); 125 } 126 127 static void vfio_migration_set_device_state(VFIODevice *vbasedev, 128 enum vfio_device_mig_state state) 129 { 130 VFIOMigration *migration = vbasedev->migration; 131 132 trace_vfio_migration_set_device_state(vbasedev->name, 133 mig_state_to_str(state)); 134 135 migration->device_state = state; 136 vfio_migration_send_event(vbasedev); 137 } 138 139 static int vfio_migration_set_state(VFIODevice *vbasedev, 140 enum vfio_device_mig_state new_state, 141 enum vfio_device_mig_state recover_state, 142 Error **errp) 143 { 144 VFIOMigration *migration = vbasedev->migration; 145 uint64_t buf[DIV_ROUND_UP(sizeof(struct vfio_device_feature) + 146 sizeof(struct vfio_device_feature_mig_state), 147 sizeof(uint64_t))] = {}; 148 struct vfio_device_feature *feature = (struct vfio_device_feature *)buf; 149 struct vfio_device_feature_mig_state *mig_state = 150 (struct vfio_device_feature_mig_state *)feature->data; 151 int ret; 152 g_autofree char *error_prefix = 153 g_strdup_printf("%s: Failed setting device state to %s.", 154 vbasedev->name, mig_state_to_str(new_state)); 155 156 trace_vfio_migration_set_state(vbasedev->name, mig_state_to_str(new_state), 157 mig_state_to_str(recover_state)); 158 159 if (new_state == migration->device_state) { 160 return 0; 161 } 162 163 feature->argsz = sizeof(buf); 164 feature->flags = 165 VFIO_DEVICE_FEATURE_SET | VFIO_DEVICE_FEATURE_MIG_DEVICE_STATE; 166 mig_state->device_state = new_state; 167 if (ioctl(vbasedev->fd, VFIO_DEVICE_FEATURE, feature)) { 168 /* Try to set the device in some good state */ 169 ret = -errno; 170 171 if (recover_state == VFIO_DEVICE_STATE_ERROR) { 172 error_setg_errno(errp, errno, 173 "%s Recover state is ERROR. Resetting device", 174 error_prefix); 175 176 goto reset_device; 177 } 178 179 error_setg_errno(errp, errno, 180 "%s Setting device in recover state %s", 181 error_prefix, mig_state_to_str(recover_state)); 182 183 mig_state->device_state = recover_state; 184 if (ioctl(vbasedev->fd, VFIO_DEVICE_FEATURE, feature)) { 185 ret = -errno; 186 /* 187 * If setting the device in recover state fails, report 188 * the error here and propagate the first error. 189 */ 190 error_report( 191 "%s: Failed setting device in recover state, err: %s. Resetting device", 192 vbasedev->name, strerror(errno)); 193 194 goto reset_device; 195 } 196 197 vfio_migration_set_device_state(vbasedev, recover_state); 198 199 return ret; 200 } 201 202 vfio_migration_set_device_state(vbasedev, new_state); 203 if (mig_state->data_fd != -1) { 204 if (migration->data_fd != -1) { 205 /* 206 * This can happen if the device is asynchronously reset and 207 * terminates a data transfer. 208 */ 209 error_setg(errp, "%s: data_fd out of sync", vbasedev->name); 210 close(mig_state->data_fd); 211 212 return -EBADF; 213 } 214 215 migration->data_fd = mig_state->data_fd; 216 } 217 218 return 0; 219 220 reset_device: 221 if (ioctl(vbasedev->fd, VFIO_DEVICE_RESET)) { 222 hw_error("%s: Failed resetting device, err: %s", vbasedev->name, 223 strerror(errno)); 224 } 225 226 vfio_migration_set_device_state(vbasedev, VFIO_DEVICE_STATE_RUNNING); 227 228 return ret; 229 } 230 231 /* 232 * Some device state transitions require resetting the device if they fail. 233 * This function sets the device in new_state and resets the device if that 234 * fails. Reset is done by using ERROR as the recover state. 235 */ 236 static int 237 vfio_migration_set_state_or_reset(VFIODevice *vbasedev, 238 enum vfio_device_mig_state new_state, 239 Error **errp) 240 { 241 return vfio_migration_set_state(vbasedev, new_state, 242 VFIO_DEVICE_STATE_ERROR, errp); 243 } 244 245 static int vfio_load_buffer(QEMUFile *f, VFIODevice *vbasedev, 246 uint64_t data_size) 247 { 248 VFIOMigration *migration = vbasedev->migration; 249 int ret; 250 251 ret = qemu_file_get_to_fd(f, migration->data_fd, data_size); 252 trace_vfio_load_state_device_data(vbasedev->name, data_size, ret); 253 254 return ret; 255 } 256 257 static int vfio_save_device_config_state(QEMUFile *f, void *opaque, 258 Error **errp) 259 { 260 VFIODevice *vbasedev = opaque; 261 int ret; 262 263 qemu_put_be64(f, VFIO_MIG_FLAG_DEV_CONFIG_STATE); 264 265 if (vbasedev->ops && vbasedev->ops->vfio_save_config) { 266 ret = vbasedev->ops->vfio_save_config(vbasedev, f, errp); 267 if (ret) { 268 return ret; 269 } 270 } 271 272 qemu_put_be64(f, VFIO_MIG_FLAG_END_OF_STATE); 273 274 trace_vfio_save_device_config_state(vbasedev->name); 275 276 ret = qemu_file_get_error(f); 277 if (ret < 0) { 278 error_setg_errno(errp, -ret, "Failed to save state"); 279 } 280 return ret; 281 } 282 283 static int vfio_load_device_config_state(QEMUFile *f, void *opaque) 284 { 285 VFIODevice *vbasedev = opaque; 286 uint64_t data; 287 288 if (vbasedev->ops && vbasedev->ops->vfio_load_config) { 289 int ret; 290 291 ret = vbasedev->ops->vfio_load_config(vbasedev, f); 292 if (ret) { 293 error_report("%s: Failed to load device config space", 294 vbasedev->name); 295 return ret; 296 } 297 } 298 299 data = qemu_get_be64(f); 300 if (data != VFIO_MIG_FLAG_END_OF_STATE) { 301 error_report("%s: Failed loading device config space, " 302 "end flag incorrect 0x%"PRIx64, vbasedev->name, data); 303 return -EINVAL; 304 } 305 306 trace_vfio_load_device_config_state(vbasedev->name); 307 return qemu_file_get_error(f); 308 } 309 310 static void vfio_migration_cleanup(VFIODevice *vbasedev) 311 { 312 VFIOMigration *migration = vbasedev->migration; 313 314 close(migration->data_fd); 315 migration->data_fd = -1; 316 } 317 318 static int vfio_query_stop_copy_size(VFIODevice *vbasedev, 319 uint64_t *stop_copy_size) 320 { 321 uint64_t buf[DIV_ROUND_UP(sizeof(struct vfio_device_feature) + 322 sizeof(struct vfio_device_feature_mig_data_size), 323 sizeof(uint64_t))] = {}; 324 struct vfio_device_feature *feature = (struct vfio_device_feature *)buf; 325 struct vfio_device_feature_mig_data_size *mig_data_size = 326 (struct vfio_device_feature_mig_data_size *)feature->data; 327 328 feature->argsz = sizeof(buf); 329 feature->flags = 330 VFIO_DEVICE_FEATURE_GET | VFIO_DEVICE_FEATURE_MIG_DATA_SIZE; 331 332 if (ioctl(vbasedev->fd, VFIO_DEVICE_FEATURE, feature)) { 333 return -errno; 334 } 335 336 *stop_copy_size = mig_data_size->stop_copy_length; 337 338 return 0; 339 } 340 341 static int vfio_query_precopy_size(VFIOMigration *migration) 342 { 343 struct vfio_precopy_info precopy = { 344 .argsz = sizeof(precopy), 345 }; 346 347 migration->precopy_init_size = 0; 348 migration->precopy_dirty_size = 0; 349 350 if (ioctl(migration->data_fd, VFIO_MIG_GET_PRECOPY_INFO, &precopy)) { 351 return -errno; 352 } 353 354 migration->precopy_init_size = precopy.initial_bytes; 355 migration->precopy_dirty_size = precopy.dirty_bytes; 356 357 return 0; 358 } 359 360 /* Returns the size of saved data on success and -errno on error */ 361 static ssize_t vfio_save_block(QEMUFile *f, VFIOMigration *migration) 362 { 363 ssize_t data_size; 364 365 data_size = read(migration->data_fd, migration->data_buffer, 366 migration->data_buffer_size); 367 if (data_size < 0) { 368 /* 369 * Pre-copy emptied all the device state for now. For more information, 370 * please refer to the Linux kernel VFIO uAPI. 371 */ 372 if (errno == ENOMSG) { 373 return 0; 374 } 375 376 return -errno; 377 } 378 if (data_size == 0) { 379 return 0; 380 } 381 382 qemu_put_be64(f, VFIO_MIG_FLAG_DEV_DATA_STATE); 383 qemu_put_be64(f, data_size); 384 qemu_put_buffer(f, migration->data_buffer, data_size); 385 bytes_transferred += data_size; 386 387 trace_vfio_save_block(migration->vbasedev->name, data_size); 388 389 return qemu_file_get_error(f) ?: data_size; 390 } 391 392 static void vfio_update_estimated_pending_data(VFIOMigration *migration, 393 uint64_t data_size) 394 { 395 if (!data_size) { 396 /* 397 * Pre-copy emptied all the device state for now, update estimated sizes 398 * accordingly. 399 */ 400 migration->precopy_init_size = 0; 401 migration->precopy_dirty_size = 0; 402 403 return; 404 } 405 406 if (migration->precopy_init_size) { 407 uint64_t init_size = MIN(migration->precopy_init_size, data_size); 408 409 migration->precopy_init_size -= init_size; 410 data_size -= init_size; 411 } 412 413 migration->precopy_dirty_size -= MIN(migration->precopy_dirty_size, 414 data_size); 415 } 416 417 static bool vfio_precopy_supported(VFIODevice *vbasedev) 418 { 419 VFIOMigration *migration = vbasedev->migration; 420 421 return migration->mig_flags & VFIO_MIGRATION_PRE_COPY; 422 } 423 424 /* ---------------------------------------------------------------------- */ 425 426 static int vfio_save_prepare(void *opaque, Error **errp) 427 { 428 VFIODevice *vbasedev = opaque; 429 430 /* 431 * Snapshot doesn't use postcopy nor background snapshot, so allow snapshot 432 * even if they are on. 433 */ 434 if (runstate_check(RUN_STATE_SAVE_VM)) { 435 return 0; 436 } 437 438 if (migrate_postcopy_ram()) { 439 error_setg( 440 errp, "%s: VFIO migration is not supported with postcopy migration", 441 vbasedev->name); 442 return -EOPNOTSUPP; 443 } 444 445 if (migrate_background_snapshot()) { 446 error_setg( 447 errp, 448 "%s: VFIO migration is not supported with background snapshot", 449 vbasedev->name); 450 return -EOPNOTSUPP; 451 } 452 453 return 0; 454 } 455 456 static int vfio_save_setup(QEMUFile *f, void *opaque, Error **errp) 457 { 458 VFIODevice *vbasedev = opaque; 459 VFIOMigration *migration = vbasedev->migration; 460 uint64_t stop_copy_size = VFIO_MIG_DEFAULT_DATA_BUFFER_SIZE; 461 int ret; 462 463 qemu_put_be64(f, VFIO_MIG_FLAG_DEV_SETUP_STATE); 464 465 vfio_query_stop_copy_size(vbasedev, &stop_copy_size); 466 migration->data_buffer_size = MIN(VFIO_MIG_DEFAULT_DATA_BUFFER_SIZE, 467 stop_copy_size); 468 migration->data_buffer = g_try_malloc0(migration->data_buffer_size); 469 if (!migration->data_buffer) { 470 error_setg(errp, "%s: Failed to allocate migration data buffer", 471 vbasedev->name); 472 return -ENOMEM; 473 } 474 475 if (vfio_precopy_supported(vbasedev)) { 476 switch (migration->device_state) { 477 case VFIO_DEVICE_STATE_RUNNING: 478 ret = vfio_migration_set_state(vbasedev, VFIO_DEVICE_STATE_PRE_COPY, 479 VFIO_DEVICE_STATE_RUNNING, errp); 480 if (ret) { 481 return ret; 482 } 483 484 vfio_query_precopy_size(migration); 485 486 break; 487 case VFIO_DEVICE_STATE_STOP: 488 /* vfio_save_complete_precopy() will go to STOP_COPY */ 489 break; 490 default: 491 error_setg(errp, "%s: Invalid device state %d", vbasedev->name, 492 migration->device_state); 493 return -EINVAL; 494 } 495 } 496 497 trace_vfio_save_setup(vbasedev->name, migration->data_buffer_size); 498 499 qemu_put_be64(f, VFIO_MIG_FLAG_END_OF_STATE); 500 501 ret = qemu_file_get_error(f); 502 if (ret < 0) { 503 error_setg_errno(errp, -ret, "%s: save setup failed", vbasedev->name); 504 } 505 506 return ret; 507 } 508 509 static void vfio_save_cleanup(void *opaque) 510 { 511 VFIODevice *vbasedev = opaque; 512 VFIOMigration *migration = vbasedev->migration; 513 Error *local_err = NULL; 514 int ret; 515 516 /* 517 * Changing device state from STOP_COPY to STOP can take time. Do it here, 518 * after migration has completed, so it won't increase downtime. 519 */ 520 if (migration->device_state == VFIO_DEVICE_STATE_STOP_COPY) { 521 ret = vfio_migration_set_state_or_reset(vbasedev, 522 VFIO_DEVICE_STATE_STOP, 523 &local_err); 524 if (ret) { 525 error_report_err(local_err); 526 } 527 } 528 529 g_free(migration->data_buffer); 530 migration->data_buffer = NULL; 531 migration->precopy_init_size = 0; 532 migration->precopy_dirty_size = 0; 533 migration->initial_data_sent = false; 534 vfio_migration_cleanup(vbasedev); 535 trace_vfio_save_cleanup(vbasedev->name); 536 } 537 538 static void vfio_state_pending_estimate(void *opaque, uint64_t *must_precopy, 539 uint64_t *can_postcopy) 540 { 541 VFIODevice *vbasedev = opaque; 542 VFIOMigration *migration = vbasedev->migration; 543 544 if (!vfio_device_state_is_precopy(vbasedev)) { 545 return; 546 } 547 548 *must_precopy += 549 migration->precopy_init_size + migration->precopy_dirty_size; 550 551 trace_vfio_state_pending_estimate(vbasedev->name, *must_precopy, 552 *can_postcopy, 553 migration->precopy_init_size, 554 migration->precopy_dirty_size); 555 } 556 557 /* 558 * Migration size of VFIO devices can be as little as a few KBs or as big as 559 * many GBs. This value should be big enough to cover the worst case. 560 */ 561 #define VFIO_MIG_STOP_COPY_SIZE (100 * GiB) 562 563 static void vfio_state_pending_exact(void *opaque, uint64_t *must_precopy, 564 uint64_t *can_postcopy) 565 { 566 VFIODevice *vbasedev = opaque; 567 VFIOMigration *migration = vbasedev->migration; 568 uint64_t stop_copy_size = VFIO_MIG_STOP_COPY_SIZE; 569 570 /* 571 * If getting pending migration size fails, VFIO_MIG_STOP_COPY_SIZE is 572 * reported so downtime limit won't be violated. 573 */ 574 vfio_query_stop_copy_size(vbasedev, &stop_copy_size); 575 *must_precopy += stop_copy_size; 576 577 if (vfio_device_state_is_precopy(vbasedev)) { 578 vfio_query_precopy_size(migration); 579 580 *must_precopy += 581 migration->precopy_init_size + migration->precopy_dirty_size; 582 } 583 584 trace_vfio_state_pending_exact(vbasedev->name, *must_precopy, *can_postcopy, 585 stop_copy_size, migration->precopy_init_size, 586 migration->precopy_dirty_size); 587 } 588 589 static bool vfio_is_active_iterate(void *opaque) 590 { 591 VFIODevice *vbasedev = opaque; 592 593 return vfio_device_state_is_precopy(vbasedev); 594 } 595 596 /* 597 * Note about migration rate limiting: VFIO migration buffer size is currently 598 * limited to 1MB, so there is no need to check if migration rate exceeded (as 599 * in the worst case it will exceed by 1MB). However, if the buffer size is 600 * later changed to a bigger value, migration rate should be enforced here. 601 */ 602 static int vfio_save_iterate(QEMUFile *f, void *opaque) 603 { 604 VFIODevice *vbasedev = opaque; 605 VFIOMigration *migration = vbasedev->migration; 606 ssize_t data_size; 607 608 data_size = vfio_save_block(f, migration); 609 if (data_size < 0) { 610 return data_size; 611 } 612 613 vfio_update_estimated_pending_data(migration, data_size); 614 615 if (migrate_switchover_ack() && !migration->precopy_init_size && 616 !migration->initial_data_sent) { 617 qemu_put_be64(f, VFIO_MIG_FLAG_DEV_INIT_DATA_SENT); 618 migration->initial_data_sent = true; 619 } else { 620 qemu_put_be64(f, VFIO_MIG_FLAG_END_OF_STATE); 621 } 622 623 trace_vfio_save_iterate(vbasedev->name, migration->precopy_init_size, 624 migration->precopy_dirty_size); 625 626 return !migration->precopy_init_size && !migration->precopy_dirty_size; 627 } 628 629 static int vfio_save_complete_precopy(QEMUFile *f, void *opaque) 630 { 631 VFIODevice *vbasedev = opaque; 632 ssize_t data_size; 633 int ret; 634 Error *local_err = NULL; 635 636 /* We reach here with device state STOP or STOP_COPY only */ 637 ret = vfio_migration_set_state(vbasedev, VFIO_DEVICE_STATE_STOP_COPY, 638 VFIO_DEVICE_STATE_STOP, &local_err); 639 if (ret) { 640 error_report_err(local_err); 641 return ret; 642 } 643 644 do { 645 data_size = vfio_save_block(f, vbasedev->migration); 646 if (data_size < 0) { 647 return data_size; 648 } 649 } while (data_size); 650 651 qemu_put_be64(f, VFIO_MIG_FLAG_END_OF_STATE); 652 ret = qemu_file_get_error(f); 653 654 trace_vfio_save_complete_precopy(vbasedev->name, ret); 655 656 return ret; 657 } 658 659 static void vfio_save_state(QEMUFile *f, void *opaque) 660 { 661 VFIODevice *vbasedev = opaque; 662 Error *local_err = NULL; 663 int ret; 664 665 ret = vfio_save_device_config_state(f, opaque, &local_err); 666 if (ret) { 667 error_prepend(&local_err, 668 "vfio: Failed to save device config space of %s - ", 669 vbasedev->name); 670 qemu_file_set_error_obj(f, ret, local_err); 671 } 672 } 673 674 static int vfio_load_setup(QEMUFile *f, void *opaque, Error **errp) 675 { 676 VFIODevice *vbasedev = opaque; 677 678 return vfio_migration_set_state(vbasedev, VFIO_DEVICE_STATE_RESUMING, 679 vbasedev->migration->device_state, errp); 680 } 681 682 static int vfio_load_cleanup(void *opaque) 683 { 684 VFIODevice *vbasedev = opaque; 685 686 vfio_migration_cleanup(vbasedev); 687 trace_vfio_load_cleanup(vbasedev->name); 688 689 return 0; 690 } 691 692 static int vfio_load_state(QEMUFile *f, void *opaque, int version_id) 693 { 694 VFIODevice *vbasedev = opaque; 695 int ret = 0; 696 uint64_t data; 697 698 data = qemu_get_be64(f); 699 while (data != VFIO_MIG_FLAG_END_OF_STATE) { 700 701 trace_vfio_load_state(vbasedev->name, data); 702 703 switch (data) { 704 case VFIO_MIG_FLAG_DEV_CONFIG_STATE: 705 { 706 return vfio_load_device_config_state(f, opaque); 707 } 708 case VFIO_MIG_FLAG_DEV_SETUP_STATE: 709 { 710 data = qemu_get_be64(f); 711 if (data == VFIO_MIG_FLAG_END_OF_STATE) { 712 return ret; 713 } else { 714 error_report("%s: SETUP STATE: EOS not found 0x%"PRIx64, 715 vbasedev->name, data); 716 return -EINVAL; 717 } 718 break; 719 } 720 case VFIO_MIG_FLAG_DEV_DATA_STATE: 721 { 722 uint64_t data_size = qemu_get_be64(f); 723 724 if (data_size) { 725 ret = vfio_load_buffer(f, vbasedev, data_size); 726 if (ret < 0) { 727 return ret; 728 } 729 } 730 break; 731 } 732 case VFIO_MIG_FLAG_DEV_INIT_DATA_SENT: 733 { 734 if (!vfio_precopy_supported(vbasedev) || 735 !migrate_switchover_ack()) { 736 error_report("%s: Received INIT_DATA_SENT but switchover ack " 737 "is not used", vbasedev->name); 738 return -EINVAL; 739 } 740 741 ret = qemu_loadvm_approve_switchover(); 742 if (ret) { 743 error_report( 744 "%s: qemu_loadvm_approve_switchover failed, err=%d (%s)", 745 vbasedev->name, ret, strerror(-ret)); 746 } 747 748 return ret; 749 } 750 default: 751 error_report("%s: Unknown tag 0x%"PRIx64, vbasedev->name, data); 752 return -EINVAL; 753 } 754 755 data = qemu_get_be64(f); 756 ret = qemu_file_get_error(f); 757 if (ret) { 758 return ret; 759 } 760 } 761 return ret; 762 } 763 764 static bool vfio_switchover_ack_needed(void *opaque) 765 { 766 VFIODevice *vbasedev = opaque; 767 768 return vfio_precopy_supported(vbasedev); 769 } 770 771 static const SaveVMHandlers savevm_vfio_handlers = { 772 .save_prepare = vfio_save_prepare, 773 .save_setup = vfio_save_setup, 774 .save_cleanup = vfio_save_cleanup, 775 .state_pending_estimate = vfio_state_pending_estimate, 776 .state_pending_exact = vfio_state_pending_exact, 777 .is_active_iterate = vfio_is_active_iterate, 778 .save_live_iterate = vfio_save_iterate, 779 .save_live_complete_precopy = vfio_save_complete_precopy, 780 .save_state = vfio_save_state, 781 .load_setup = vfio_load_setup, 782 .load_cleanup = vfio_load_cleanup, 783 .load_state = vfio_load_state, 784 .switchover_ack_needed = vfio_switchover_ack_needed, 785 }; 786 787 /* ---------------------------------------------------------------------- */ 788 789 static void vfio_vmstate_change_prepare(void *opaque, bool running, 790 RunState state) 791 { 792 VFIODevice *vbasedev = opaque; 793 VFIOMigration *migration = vbasedev->migration; 794 enum vfio_device_mig_state new_state; 795 Error *local_err = NULL; 796 int ret; 797 798 new_state = migration->device_state == VFIO_DEVICE_STATE_PRE_COPY ? 799 VFIO_DEVICE_STATE_PRE_COPY_P2P : 800 VFIO_DEVICE_STATE_RUNNING_P2P; 801 802 ret = vfio_migration_set_state_or_reset(vbasedev, new_state, &local_err); 803 if (ret) { 804 /* 805 * Migration should be aborted in this case, but vm_state_notify() 806 * currently does not support reporting failures. 807 */ 808 migration_file_set_error(ret, local_err); 809 } 810 811 trace_vfio_vmstate_change_prepare(vbasedev->name, running, 812 RunState_str(state), 813 mig_state_to_str(new_state)); 814 } 815 816 static void vfio_vmstate_change(void *opaque, bool running, RunState state) 817 { 818 VFIODevice *vbasedev = opaque; 819 enum vfio_device_mig_state new_state; 820 Error *local_err = NULL; 821 int ret; 822 823 if (running) { 824 new_state = VFIO_DEVICE_STATE_RUNNING; 825 } else { 826 new_state = 827 (vfio_device_state_is_precopy(vbasedev) && 828 (state == RUN_STATE_FINISH_MIGRATE || state == RUN_STATE_PAUSED)) ? 829 VFIO_DEVICE_STATE_STOP_COPY : 830 VFIO_DEVICE_STATE_STOP; 831 } 832 833 ret = vfio_migration_set_state_or_reset(vbasedev, new_state, &local_err); 834 if (ret) { 835 /* 836 * Migration should be aborted in this case, but vm_state_notify() 837 * currently does not support reporting failures. 838 */ 839 migration_file_set_error(ret, local_err); 840 } 841 842 trace_vfio_vmstate_change(vbasedev->name, running, RunState_str(state), 843 mig_state_to_str(new_state)); 844 } 845 846 static int vfio_migration_state_notifier(NotifierWithReturn *notifier, 847 MigrationEvent *e, Error **errp) 848 { 849 VFIOMigration *migration = container_of(notifier, VFIOMigration, 850 migration_state); 851 VFIODevice *vbasedev = migration->vbasedev; 852 Error *local_err = NULL; 853 int ret; 854 855 trace_vfio_migration_state_notifier(vbasedev->name, e->type); 856 857 if (e->type == MIG_EVENT_PRECOPY_FAILED) { 858 /* 859 * MigrationNotifyFunc may not return an error code and an Error 860 * object for MIG_EVENT_PRECOPY_FAILED. Hence, report the error 861 * locally and ignore the errp argument. 862 */ 863 ret = vfio_migration_set_state_or_reset(vbasedev, 864 VFIO_DEVICE_STATE_RUNNING, 865 &local_err); 866 if (ret) { 867 error_report_err(local_err); 868 } 869 } 870 return 0; 871 } 872 873 static void vfio_migration_free(VFIODevice *vbasedev) 874 { 875 g_free(vbasedev->migration); 876 vbasedev->migration = NULL; 877 } 878 879 static int vfio_migration_query_flags(VFIODevice *vbasedev, uint64_t *mig_flags) 880 { 881 uint64_t buf[DIV_ROUND_UP(sizeof(struct vfio_device_feature) + 882 sizeof(struct vfio_device_feature_migration), 883 sizeof(uint64_t))] = {}; 884 struct vfio_device_feature *feature = (struct vfio_device_feature *)buf; 885 struct vfio_device_feature_migration *mig = 886 (struct vfio_device_feature_migration *)feature->data; 887 888 feature->argsz = sizeof(buf); 889 feature->flags = VFIO_DEVICE_FEATURE_GET | VFIO_DEVICE_FEATURE_MIGRATION; 890 if (ioctl(vbasedev->fd, VFIO_DEVICE_FEATURE, feature)) { 891 return -errno; 892 } 893 894 *mig_flags = mig->flags; 895 896 return 0; 897 } 898 899 static bool vfio_dma_logging_supported(VFIODevice *vbasedev) 900 { 901 uint64_t buf[DIV_ROUND_UP(sizeof(struct vfio_device_feature), 902 sizeof(uint64_t))] = {}; 903 struct vfio_device_feature *feature = (struct vfio_device_feature *)buf; 904 905 feature->argsz = sizeof(buf); 906 feature->flags = VFIO_DEVICE_FEATURE_PROBE | 907 VFIO_DEVICE_FEATURE_DMA_LOGGING_START; 908 909 return !ioctl(vbasedev->fd, VFIO_DEVICE_FEATURE, feature); 910 } 911 912 static int vfio_migration_init(VFIODevice *vbasedev) 913 { 914 int ret; 915 Object *obj; 916 VFIOMigration *migration; 917 char id[256] = ""; 918 g_autofree char *path = NULL, *oid = NULL; 919 uint64_t mig_flags = 0; 920 VMChangeStateHandler *prepare_cb; 921 922 if (!vbasedev->ops->vfio_get_object) { 923 return -EINVAL; 924 } 925 926 obj = vbasedev->ops->vfio_get_object(vbasedev); 927 if (!obj) { 928 return -EINVAL; 929 } 930 931 ret = vfio_migration_query_flags(vbasedev, &mig_flags); 932 if (ret) { 933 return ret; 934 } 935 936 /* Basic migration functionality must be supported */ 937 if (!(mig_flags & VFIO_MIGRATION_STOP_COPY)) { 938 return -EOPNOTSUPP; 939 } 940 941 vbasedev->migration = g_new0(VFIOMigration, 1); 942 migration = vbasedev->migration; 943 migration->vbasedev = vbasedev; 944 migration->device_state = VFIO_DEVICE_STATE_RUNNING; 945 migration->data_fd = -1; 946 migration->mig_flags = mig_flags; 947 948 vbasedev->dirty_pages_supported = vfio_dma_logging_supported(vbasedev); 949 950 oid = vmstate_if_get_id(VMSTATE_IF(DEVICE(obj))); 951 if (oid) { 952 path = g_strdup_printf("%s/vfio", oid); 953 } else { 954 path = g_strdup("vfio"); 955 } 956 strpadcpy(id, sizeof(id), path, '\0'); 957 958 register_savevm_live(id, VMSTATE_INSTANCE_ID_ANY, 1, &savevm_vfio_handlers, 959 vbasedev); 960 961 prepare_cb = migration->mig_flags & VFIO_MIGRATION_P2P ? 962 vfio_vmstate_change_prepare : 963 NULL; 964 migration->vm_state = qdev_add_vm_change_state_handler_full( 965 vbasedev->dev, vfio_vmstate_change, prepare_cb, vbasedev); 966 migration_add_notifier(&migration->migration_state, 967 vfio_migration_state_notifier); 968 969 return 0; 970 } 971 972 static void vfio_migration_deinit(VFIODevice *vbasedev) 973 { 974 VFIOMigration *migration = vbasedev->migration; 975 976 migration_remove_notifier(&migration->migration_state); 977 qemu_del_vm_change_state_handler(migration->vm_state); 978 unregister_savevm(VMSTATE_IF(vbasedev->dev), "vfio", vbasedev); 979 vfio_migration_free(vbasedev); 980 vfio_unblock_multiple_devices_migration(); 981 } 982 983 static int vfio_block_migration(VFIODevice *vbasedev, Error *err, Error **errp) 984 { 985 if (vbasedev->enable_migration == ON_OFF_AUTO_ON) { 986 error_propagate(errp, err); 987 return -EINVAL; 988 } 989 990 vbasedev->migration_blocker = error_copy(err); 991 error_free(err); 992 993 return migrate_add_blocker_normal(&vbasedev->migration_blocker, errp); 994 } 995 996 /* ---------------------------------------------------------------------- */ 997 998 int64_t vfio_mig_bytes_transferred(void) 999 { 1000 return bytes_transferred; 1001 } 1002 1003 void vfio_reset_bytes_transferred(void) 1004 { 1005 bytes_transferred = 0; 1006 } 1007 1008 /* 1009 * Return true when either migration initialized or blocker registered. 1010 * Currently only return false when adding blocker fails which will 1011 * de-register vfio device. 1012 */ 1013 bool vfio_migration_realize(VFIODevice *vbasedev, Error **errp) 1014 { 1015 Error *err = NULL; 1016 int ret; 1017 1018 if (vbasedev->enable_migration == ON_OFF_AUTO_OFF) { 1019 error_setg(&err, "%s: Migration is disabled for VFIO device", 1020 vbasedev->name); 1021 return !vfio_block_migration(vbasedev, err, errp); 1022 } 1023 1024 ret = vfio_migration_init(vbasedev); 1025 if (ret) { 1026 if (ret == -ENOTTY) { 1027 error_setg(&err, "%s: VFIO migration is not supported in kernel", 1028 vbasedev->name); 1029 } else { 1030 error_setg(&err, 1031 "%s: Migration couldn't be initialized for VFIO device, " 1032 "err: %d (%s)", 1033 vbasedev->name, ret, strerror(-ret)); 1034 } 1035 1036 return !vfio_block_migration(vbasedev, err, errp); 1037 } 1038 1039 if (!vbasedev->dirty_pages_supported) { 1040 if (vbasedev->enable_migration == ON_OFF_AUTO_AUTO) { 1041 error_setg(&err, 1042 "%s: VFIO device doesn't support device dirty tracking", 1043 vbasedev->name); 1044 goto add_blocker; 1045 } 1046 1047 warn_report("%s: VFIO device doesn't support device dirty tracking", 1048 vbasedev->name); 1049 } 1050 1051 ret = vfio_block_multiple_devices_migration(vbasedev, errp); 1052 if (ret) { 1053 goto out_deinit; 1054 } 1055 1056 if (vfio_viommu_preset(vbasedev)) { 1057 error_setg(&err, "%s: Migration is currently not supported " 1058 "with vIOMMU enabled", vbasedev->name); 1059 goto add_blocker; 1060 } 1061 1062 trace_vfio_migration_realize(vbasedev->name); 1063 return true; 1064 1065 add_blocker: 1066 ret = vfio_block_migration(vbasedev, err, errp); 1067 out_deinit: 1068 if (ret) { 1069 vfio_migration_deinit(vbasedev); 1070 } 1071 return !ret; 1072 } 1073 1074 void vfio_migration_exit(VFIODevice *vbasedev) 1075 { 1076 if (vbasedev->migration) { 1077 vfio_migration_deinit(vbasedev); 1078 } 1079 1080 migrate_del_blocker(&vbasedev->migration_blocker); 1081 } 1082