1 /* 2 * Multifd common code 3 * 4 * Copyright (c) 2019-2020 Red Hat Inc 5 * 6 * Authors: 7 * Juan Quintela <quintela@redhat.com> 8 * 9 * This work is licensed under the terms of the GNU GPL, version 2 or later. 10 * See the COPYING file in the top-level directory. 11 */ 12 13 #include "qemu/osdep.h" 14 #include "qemu/rcu.h" 15 #include "exec/target_page.h" 16 #include "sysemu/sysemu.h" 17 #include "exec/ramblock.h" 18 #include "qemu/error-report.h" 19 #include "qapi/error.h" 20 #include "ram.h" 21 #include "migration.h" 22 #include "migration-stats.h" 23 #include "socket.h" 24 #include "tls.h" 25 #include "qemu-file.h" 26 #include "trace.h" 27 #include "multifd.h" 28 #include "threadinfo.h" 29 #include "options.h" 30 #include "qemu/yank.h" 31 #include "io/channel-socket.h" 32 #include "yank_functions.h" 33 34 /* Multiple fd's */ 35 36 #define MULTIFD_MAGIC 0x11223344U 37 #define MULTIFD_VERSION 1 38 39 typedef struct { 40 uint32_t magic; 41 uint32_t version; 42 unsigned char uuid[16]; /* QemuUUID */ 43 uint8_t id; 44 uint8_t unused1[7]; /* Reserved for future use */ 45 uint64_t unused2[4]; /* Reserved for future use */ 46 } __attribute__((packed)) MultiFDInit_t; 47 48 /* Multifd without compression */ 49 50 /** 51 * nocomp_send_setup: setup send side 52 * 53 * For no compression this function does nothing. 54 * 55 * Returns 0 for success or -1 for error 56 * 57 * @p: Params for the channel that we are using 58 * @errp: pointer to an error 59 */ 60 static int nocomp_send_setup(MultiFDSendParams *p, Error **errp) 61 { 62 return 0; 63 } 64 65 /** 66 * nocomp_send_cleanup: cleanup send side 67 * 68 * For no compression this function does nothing. 69 * 70 * @p: Params for the channel that we are using 71 * @errp: pointer to an error 72 */ 73 static void nocomp_send_cleanup(MultiFDSendParams *p, Error **errp) 74 { 75 return; 76 } 77 78 /** 79 * nocomp_send_prepare: prepare date to be able to send 80 * 81 * For no compression we just have to calculate the size of the 82 * packet. 83 * 84 * Returns 0 for success or -1 for error 85 * 86 * @p: Params for the channel that we are using 87 * @errp: pointer to an error 88 */ 89 static int nocomp_send_prepare(MultiFDSendParams *p, Error **errp) 90 { 91 MultiFDPages_t *pages = p->pages; 92 93 for (int i = 0; i < p->normal_num; i++) { 94 p->iov[p->iovs_num].iov_base = pages->block->host + p->normal[i]; 95 p->iov[p->iovs_num].iov_len = p->page_size; 96 p->iovs_num++; 97 } 98 99 p->next_packet_size = p->normal_num * p->page_size; 100 p->flags |= MULTIFD_FLAG_NOCOMP; 101 return 0; 102 } 103 104 /** 105 * nocomp_recv_setup: setup receive side 106 * 107 * For no compression this function does nothing. 108 * 109 * Returns 0 for success or -1 for error 110 * 111 * @p: Params for the channel that we are using 112 * @errp: pointer to an error 113 */ 114 static int nocomp_recv_setup(MultiFDRecvParams *p, Error **errp) 115 { 116 return 0; 117 } 118 119 /** 120 * nocomp_recv_cleanup: setup receive side 121 * 122 * For no compression this function does nothing. 123 * 124 * @p: Params for the channel that we are using 125 */ 126 static void nocomp_recv_cleanup(MultiFDRecvParams *p) 127 { 128 } 129 130 /** 131 * nocomp_recv_pages: read the data from the channel into actual pages 132 * 133 * For no compression we just need to read things into the correct place. 134 * 135 * Returns 0 for success or -1 for error 136 * 137 * @p: Params for the channel that we are using 138 * @errp: pointer to an error 139 */ 140 static int nocomp_recv_pages(MultiFDRecvParams *p, Error **errp) 141 { 142 uint32_t flags = p->flags & MULTIFD_FLAG_COMPRESSION_MASK; 143 144 if (flags != MULTIFD_FLAG_NOCOMP) { 145 error_setg(errp, "multifd %u: flags received %x flags expected %x", 146 p->id, flags, MULTIFD_FLAG_NOCOMP); 147 return -1; 148 } 149 for (int i = 0; i < p->normal_num; i++) { 150 p->iov[i].iov_base = p->host + p->normal[i]; 151 p->iov[i].iov_len = p->page_size; 152 } 153 return qio_channel_readv_all(p->c, p->iov, p->normal_num, errp); 154 } 155 156 static MultiFDMethods multifd_nocomp_ops = { 157 .send_setup = nocomp_send_setup, 158 .send_cleanup = nocomp_send_cleanup, 159 .send_prepare = nocomp_send_prepare, 160 .recv_setup = nocomp_recv_setup, 161 .recv_cleanup = nocomp_recv_cleanup, 162 .recv_pages = nocomp_recv_pages 163 }; 164 165 static MultiFDMethods *multifd_ops[MULTIFD_COMPRESSION__MAX] = { 166 [MULTIFD_COMPRESSION_NONE] = &multifd_nocomp_ops, 167 }; 168 169 void multifd_register_ops(int method, MultiFDMethods *ops) 170 { 171 assert(0 < method && method < MULTIFD_COMPRESSION__MAX); 172 multifd_ops[method] = ops; 173 } 174 175 static int multifd_send_initial_packet(MultiFDSendParams *p, Error **errp) 176 { 177 MultiFDInit_t msg = {}; 178 int ret; 179 180 msg.magic = cpu_to_be32(MULTIFD_MAGIC); 181 msg.version = cpu_to_be32(MULTIFD_VERSION); 182 msg.id = p->id; 183 memcpy(msg.uuid, &qemu_uuid.data, sizeof(msg.uuid)); 184 185 ret = qio_channel_write_all(p->c, (char *)&msg, sizeof(msg), errp); 186 if (ret != 0) { 187 return -1; 188 } 189 return 0; 190 } 191 192 static int multifd_recv_initial_packet(QIOChannel *c, Error **errp) 193 { 194 MultiFDInit_t msg; 195 int ret; 196 197 ret = qio_channel_read_all(c, (char *)&msg, sizeof(msg), errp); 198 if (ret != 0) { 199 return -1; 200 } 201 202 msg.magic = be32_to_cpu(msg.magic); 203 msg.version = be32_to_cpu(msg.version); 204 205 if (msg.magic != MULTIFD_MAGIC) { 206 error_setg(errp, "multifd: received packet magic %x " 207 "expected %x", msg.magic, MULTIFD_MAGIC); 208 return -1; 209 } 210 211 if (msg.version != MULTIFD_VERSION) { 212 error_setg(errp, "multifd: received packet version %u " 213 "expected %u", msg.version, MULTIFD_VERSION); 214 return -1; 215 } 216 217 if (memcmp(msg.uuid, &qemu_uuid, sizeof(qemu_uuid))) { 218 char *uuid = qemu_uuid_unparse_strdup(&qemu_uuid); 219 char *msg_uuid = qemu_uuid_unparse_strdup((const QemuUUID *)msg.uuid); 220 221 error_setg(errp, "multifd: received uuid '%s' and expected " 222 "uuid '%s' for channel %hhd", msg_uuid, uuid, msg.id); 223 g_free(uuid); 224 g_free(msg_uuid); 225 return -1; 226 } 227 228 if (msg.id > migrate_multifd_channels()) { 229 error_setg(errp, "multifd: received channel version %u " 230 "expected %u", msg.version, MULTIFD_VERSION); 231 return -1; 232 } 233 234 return msg.id; 235 } 236 237 static MultiFDPages_t *multifd_pages_init(size_t size) 238 { 239 MultiFDPages_t *pages = g_new0(MultiFDPages_t, 1); 240 241 pages->allocated = size; 242 pages->offset = g_new0(ram_addr_t, size); 243 244 return pages; 245 } 246 247 static void multifd_pages_clear(MultiFDPages_t *pages) 248 { 249 pages->num = 0; 250 pages->allocated = 0; 251 pages->packet_num = 0; 252 pages->block = NULL; 253 g_free(pages->offset); 254 pages->offset = NULL; 255 g_free(pages); 256 } 257 258 static void multifd_send_fill_packet(MultiFDSendParams *p) 259 { 260 MultiFDPacket_t *packet = p->packet; 261 int i; 262 263 packet->flags = cpu_to_be32(p->flags); 264 packet->pages_alloc = cpu_to_be32(p->pages->allocated); 265 packet->normal_pages = cpu_to_be32(p->normal_num); 266 packet->next_packet_size = cpu_to_be32(p->next_packet_size); 267 packet->packet_num = cpu_to_be64(p->packet_num); 268 269 if (p->pages->block) { 270 strncpy(packet->ramblock, p->pages->block->idstr, 256); 271 } 272 273 for (i = 0; i < p->normal_num; i++) { 274 /* there are architectures where ram_addr_t is 32 bit */ 275 uint64_t temp = p->normal[i]; 276 277 packet->offset[i] = cpu_to_be64(temp); 278 } 279 } 280 281 static int multifd_recv_unfill_packet(MultiFDRecvParams *p, Error **errp) 282 { 283 MultiFDPacket_t *packet = p->packet; 284 int i; 285 286 packet->magic = be32_to_cpu(packet->magic); 287 if (packet->magic != MULTIFD_MAGIC) { 288 error_setg(errp, "multifd: received packet " 289 "magic %x and expected magic %x", 290 packet->magic, MULTIFD_MAGIC); 291 return -1; 292 } 293 294 packet->version = be32_to_cpu(packet->version); 295 if (packet->version != MULTIFD_VERSION) { 296 error_setg(errp, "multifd: received packet " 297 "version %u and expected version %u", 298 packet->version, MULTIFD_VERSION); 299 return -1; 300 } 301 302 p->flags = be32_to_cpu(packet->flags); 303 304 packet->pages_alloc = be32_to_cpu(packet->pages_alloc); 305 /* 306 * If we received a packet that is 100 times bigger than expected 307 * just stop migration. It is a magic number. 308 */ 309 if (packet->pages_alloc > p->page_count) { 310 error_setg(errp, "multifd: received packet " 311 "with size %u and expected a size of %u", 312 packet->pages_alloc, p->page_count) ; 313 return -1; 314 } 315 316 p->normal_num = be32_to_cpu(packet->normal_pages); 317 if (p->normal_num > packet->pages_alloc) { 318 error_setg(errp, "multifd: received packet " 319 "with %u pages and expected maximum pages are %u", 320 p->normal_num, packet->pages_alloc) ; 321 return -1; 322 } 323 324 p->next_packet_size = be32_to_cpu(packet->next_packet_size); 325 p->packet_num = be64_to_cpu(packet->packet_num); 326 327 if (p->normal_num == 0) { 328 return 0; 329 } 330 331 /* make sure that ramblock is 0 terminated */ 332 packet->ramblock[255] = 0; 333 p->block = qemu_ram_block_by_name(packet->ramblock); 334 if (!p->block) { 335 error_setg(errp, "multifd: unknown ram block %s", 336 packet->ramblock); 337 return -1; 338 } 339 340 p->host = p->block->host; 341 for (i = 0; i < p->normal_num; i++) { 342 uint64_t offset = be64_to_cpu(packet->offset[i]); 343 344 if (offset > (p->block->used_length - p->page_size)) { 345 error_setg(errp, "multifd: offset too long %" PRIu64 346 " (max " RAM_ADDR_FMT ")", 347 offset, p->block->used_length); 348 return -1; 349 } 350 p->normal[i] = offset; 351 } 352 353 return 0; 354 } 355 356 struct { 357 MultiFDSendParams *params; 358 /* array of pages to sent */ 359 MultiFDPages_t *pages; 360 /* global number of generated multifd packets */ 361 uint64_t packet_num; 362 /* send channels ready */ 363 QemuSemaphore channels_ready; 364 /* 365 * Have we already run terminate threads. There is a race when it 366 * happens that we got one error while we are exiting. 367 * We will use atomic operations. Only valid values are 0 and 1. 368 */ 369 int exiting; 370 /* multifd ops */ 371 MultiFDMethods *ops; 372 } *multifd_send_state; 373 374 /* 375 * How we use multifd_send_state->pages and channel->pages? 376 * 377 * We create a pages for each channel, and a main one. Each time that 378 * we need to send a batch of pages we interchange the ones between 379 * multifd_send_state and the channel that is sending it. There are 380 * two reasons for that: 381 * - to not have to do so many mallocs during migration 382 * - to make easier to know what to free at the end of migration 383 * 384 * This way we always know who is the owner of each "pages" struct, 385 * and we don't need any locking. It belongs to the migration thread 386 * or to the channel thread. Switching is safe because the migration 387 * thread is using the channel mutex when changing it, and the channel 388 * have to had finish with its own, otherwise pending_job can't be 389 * false. 390 */ 391 392 static int multifd_send_pages(QEMUFile *f) 393 { 394 int i; 395 static int next_channel; 396 MultiFDSendParams *p = NULL; /* make happy gcc */ 397 MultiFDPages_t *pages = multifd_send_state->pages; 398 uint64_t transferred; 399 400 if (qatomic_read(&multifd_send_state->exiting)) { 401 return -1; 402 } 403 404 qemu_sem_wait(&multifd_send_state->channels_ready); 405 /* 406 * next_channel can remain from a previous migration that was 407 * using more channels, so ensure it doesn't overflow if the 408 * limit is lower now. 409 */ 410 next_channel %= migrate_multifd_channels(); 411 for (i = next_channel;; i = (i + 1) % migrate_multifd_channels()) { 412 p = &multifd_send_state->params[i]; 413 414 qemu_mutex_lock(&p->mutex); 415 if (p->quit) { 416 error_report("%s: channel %d has already quit!", __func__, i); 417 qemu_mutex_unlock(&p->mutex); 418 return -1; 419 } 420 if (!p->pending_job) { 421 p->pending_job++; 422 next_channel = (i + 1) % migrate_multifd_channels(); 423 break; 424 } 425 qemu_mutex_unlock(&p->mutex); 426 } 427 assert(!p->pages->num); 428 assert(!p->pages->block); 429 430 p->packet_num = multifd_send_state->packet_num++; 431 multifd_send_state->pages = p->pages; 432 p->pages = pages; 433 transferred = ((uint64_t) pages->num) * p->page_size + p->packet_len; 434 qemu_file_acct_rate_limit(f, transferred); 435 qemu_mutex_unlock(&p->mutex); 436 stat64_add(&mig_stats.transferred, transferred); 437 stat64_add(&mig_stats.multifd_bytes, transferred); 438 qemu_sem_post(&p->sem); 439 440 return 1; 441 } 442 443 int multifd_queue_page(QEMUFile *f, RAMBlock *block, ram_addr_t offset) 444 { 445 MultiFDPages_t *pages = multifd_send_state->pages; 446 bool changed = false; 447 448 if (!pages->block) { 449 pages->block = block; 450 } 451 452 if (pages->block == block) { 453 pages->offset[pages->num] = offset; 454 pages->num++; 455 456 if (pages->num < pages->allocated) { 457 return 1; 458 } 459 } else { 460 changed = true; 461 } 462 463 if (multifd_send_pages(f) < 0) { 464 return -1; 465 } 466 467 if (changed) { 468 return multifd_queue_page(f, block, offset); 469 } 470 471 return 1; 472 } 473 474 static void multifd_send_terminate_threads(Error *err) 475 { 476 int i; 477 478 trace_multifd_send_terminate_threads(err != NULL); 479 480 if (err) { 481 MigrationState *s = migrate_get_current(); 482 migrate_set_error(s, err); 483 if (s->state == MIGRATION_STATUS_SETUP || 484 s->state == MIGRATION_STATUS_PRE_SWITCHOVER || 485 s->state == MIGRATION_STATUS_DEVICE || 486 s->state == MIGRATION_STATUS_ACTIVE) { 487 migrate_set_state(&s->state, s->state, 488 MIGRATION_STATUS_FAILED); 489 } 490 } 491 492 /* 493 * We don't want to exit each threads twice. Depending on where 494 * we get the error, or if there are two independent errors in two 495 * threads at the same time, we can end calling this function 496 * twice. 497 */ 498 if (qatomic_xchg(&multifd_send_state->exiting, 1)) { 499 return; 500 } 501 502 for (i = 0; i < migrate_multifd_channels(); i++) { 503 MultiFDSendParams *p = &multifd_send_state->params[i]; 504 505 qemu_mutex_lock(&p->mutex); 506 p->quit = true; 507 qemu_sem_post(&p->sem); 508 if (p->c) { 509 qio_channel_shutdown(p->c, QIO_CHANNEL_SHUTDOWN_BOTH, NULL); 510 } 511 qemu_mutex_unlock(&p->mutex); 512 } 513 } 514 515 void multifd_save_cleanup(void) 516 { 517 int i; 518 519 if (!migrate_multifd()) { 520 return; 521 } 522 multifd_send_terminate_threads(NULL); 523 for (i = 0; i < migrate_multifd_channels(); i++) { 524 MultiFDSendParams *p = &multifd_send_state->params[i]; 525 526 if (p->running) { 527 qemu_thread_join(&p->thread); 528 } 529 } 530 for (i = 0; i < migrate_multifd_channels(); i++) { 531 MultiFDSendParams *p = &multifd_send_state->params[i]; 532 Error *local_err = NULL; 533 534 if (p->registered_yank) { 535 migration_ioc_unregister_yank(p->c); 536 } 537 socket_send_channel_destroy(p->c); 538 p->c = NULL; 539 qemu_mutex_destroy(&p->mutex); 540 qemu_sem_destroy(&p->sem); 541 qemu_sem_destroy(&p->sem_sync); 542 g_free(p->name); 543 p->name = NULL; 544 multifd_pages_clear(p->pages); 545 p->pages = NULL; 546 p->packet_len = 0; 547 g_free(p->packet); 548 p->packet = NULL; 549 g_free(p->iov); 550 p->iov = NULL; 551 g_free(p->normal); 552 p->normal = NULL; 553 multifd_send_state->ops->send_cleanup(p, &local_err); 554 if (local_err) { 555 migrate_set_error(migrate_get_current(), local_err); 556 error_free(local_err); 557 } 558 } 559 qemu_sem_destroy(&multifd_send_state->channels_ready); 560 g_free(multifd_send_state->params); 561 multifd_send_state->params = NULL; 562 multifd_pages_clear(multifd_send_state->pages); 563 multifd_send_state->pages = NULL; 564 g_free(multifd_send_state); 565 multifd_send_state = NULL; 566 } 567 568 static int multifd_zero_copy_flush(QIOChannel *c) 569 { 570 int ret; 571 Error *err = NULL; 572 573 ret = qio_channel_flush(c, &err); 574 if (ret < 0) { 575 error_report_err(err); 576 return -1; 577 } 578 if (ret == 1) { 579 stat64_add(&mig_stats.dirty_sync_missed_zero_copy, 1); 580 } 581 582 return ret; 583 } 584 585 int multifd_send_sync_main(QEMUFile *f) 586 { 587 int i; 588 bool flush_zero_copy; 589 590 if (!migrate_multifd()) { 591 return 0; 592 } 593 if (multifd_send_state->pages->num) { 594 if (multifd_send_pages(f) < 0) { 595 error_report("%s: multifd_send_pages fail", __func__); 596 return -1; 597 } 598 } 599 600 /* 601 * When using zero-copy, it's necessary to flush the pages before any of 602 * the pages can be sent again, so we'll make sure the new version of the 603 * pages will always arrive _later_ than the old pages. 604 * 605 * Currently we achieve this by flushing the zero-page requested writes 606 * per ram iteration, but in the future we could potentially optimize it 607 * to be less frequent, e.g. only after we finished one whole scanning of 608 * all the dirty bitmaps. 609 */ 610 611 flush_zero_copy = migrate_zero_copy_send(); 612 613 for (i = 0; i < migrate_multifd_channels(); i++) { 614 MultiFDSendParams *p = &multifd_send_state->params[i]; 615 616 trace_multifd_send_sync_main_signal(p->id); 617 618 qemu_mutex_lock(&p->mutex); 619 620 if (p->quit) { 621 error_report("%s: channel %d has already quit", __func__, i); 622 qemu_mutex_unlock(&p->mutex); 623 return -1; 624 } 625 626 p->packet_num = multifd_send_state->packet_num++; 627 p->flags |= MULTIFD_FLAG_SYNC; 628 p->pending_job++; 629 qemu_mutex_unlock(&p->mutex); 630 qemu_sem_post(&p->sem); 631 } 632 for (i = 0; i < migrate_multifd_channels(); i++) { 633 MultiFDSendParams *p = &multifd_send_state->params[i]; 634 635 qemu_sem_wait(&multifd_send_state->channels_ready); 636 trace_multifd_send_sync_main_wait(p->id); 637 qemu_sem_wait(&p->sem_sync); 638 639 if (flush_zero_copy && p->c && (multifd_zero_copy_flush(p->c) < 0)) { 640 return -1; 641 } 642 } 643 trace_multifd_send_sync_main(multifd_send_state->packet_num); 644 645 return 0; 646 } 647 648 static void *multifd_send_thread(void *opaque) 649 { 650 MultiFDSendParams *p = opaque; 651 MigrationThread *thread = NULL; 652 Error *local_err = NULL; 653 int ret = 0; 654 bool use_zero_copy_send = migrate_zero_copy_send(); 655 656 thread = MigrationThreadAdd(p->name, qemu_get_thread_id()); 657 658 trace_multifd_send_thread_start(p->id); 659 rcu_register_thread(); 660 661 if (multifd_send_initial_packet(p, &local_err) < 0) { 662 ret = -1; 663 goto out; 664 } 665 /* initial packet */ 666 p->num_packets = 1; 667 668 while (true) { 669 qemu_sem_post(&multifd_send_state->channels_ready); 670 qemu_sem_wait(&p->sem); 671 672 if (qatomic_read(&multifd_send_state->exiting)) { 673 break; 674 } 675 qemu_mutex_lock(&p->mutex); 676 677 if (p->pending_job) { 678 uint64_t packet_num = p->packet_num; 679 uint32_t flags; 680 p->normal_num = 0; 681 682 if (use_zero_copy_send) { 683 p->iovs_num = 0; 684 } else { 685 p->iovs_num = 1; 686 } 687 688 for (int i = 0; i < p->pages->num; i++) { 689 p->normal[p->normal_num] = p->pages->offset[i]; 690 p->normal_num++; 691 } 692 693 if (p->normal_num) { 694 ret = multifd_send_state->ops->send_prepare(p, &local_err); 695 if (ret != 0) { 696 qemu_mutex_unlock(&p->mutex); 697 break; 698 } 699 } 700 multifd_send_fill_packet(p); 701 flags = p->flags; 702 p->flags = 0; 703 p->num_packets++; 704 p->total_normal_pages += p->normal_num; 705 p->pages->num = 0; 706 p->pages->block = NULL; 707 qemu_mutex_unlock(&p->mutex); 708 709 trace_multifd_send(p->id, packet_num, p->normal_num, flags, 710 p->next_packet_size); 711 712 if (use_zero_copy_send) { 713 /* Send header first, without zerocopy */ 714 ret = qio_channel_write_all(p->c, (void *)p->packet, 715 p->packet_len, &local_err); 716 if (ret != 0) { 717 break; 718 } 719 } else { 720 /* Send header using the same writev call */ 721 p->iov[0].iov_len = p->packet_len; 722 p->iov[0].iov_base = p->packet; 723 } 724 725 ret = qio_channel_writev_full_all(p->c, p->iov, p->iovs_num, NULL, 726 0, p->write_flags, &local_err); 727 if (ret != 0) { 728 break; 729 } 730 731 qemu_mutex_lock(&p->mutex); 732 p->pending_job--; 733 qemu_mutex_unlock(&p->mutex); 734 735 if (flags & MULTIFD_FLAG_SYNC) { 736 qemu_sem_post(&p->sem_sync); 737 } 738 } else if (p->quit) { 739 qemu_mutex_unlock(&p->mutex); 740 break; 741 } else { 742 qemu_mutex_unlock(&p->mutex); 743 /* sometimes there are spurious wakeups */ 744 } 745 } 746 747 out: 748 if (local_err) { 749 trace_multifd_send_error(p->id); 750 multifd_send_terminate_threads(local_err); 751 error_free(local_err); 752 } 753 754 /* 755 * Error happen, I will exit, but I can't just leave, tell 756 * who pay attention to me. 757 */ 758 if (ret != 0) { 759 qemu_sem_post(&p->sem_sync); 760 qemu_sem_post(&multifd_send_state->channels_ready); 761 } 762 763 qemu_mutex_lock(&p->mutex); 764 p->running = false; 765 qemu_mutex_unlock(&p->mutex); 766 767 rcu_unregister_thread(); 768 MigrationThreadDel(thread); 769 trace_multifd_send_thread_end(p->id, p->num_packets, p->total_normal_pages); 770 771 return NULL; 772 } 773 774 static bool multifd_channel_connect(MultiFDSendParams *p, 775 QIOChannel *ioc, 776 Error *error); 777 778 static void multifd_tls_outgoing_handshake(QIOTask *task, 779 gpointer opaque) 780 { 781 MultiFDSendParams *p = opaque; 782 QIOChannel *ioc = QIO_CHANNEL(qio_task_get_source(task)); 783 Error *err = NULL; 784 785 if (qio_task_propagate_error(task, &err)) { 786 trace_multifd_tls_outgoing_handshake_error(ioc, error_get_pretty(err)); 787 } else { 788 trace_multifd_tls_outgoing_handshake_complete(ioc); 789 } 790 791 if (!multifd_channel_connect(p, ioc, err)) { 792 /* 793 * Error happen, mark multifd_send_thread status as 'quit' although it 794 * is not created, and then tell who pay attention to me. 795 */ 796 p->quit = true; 797 qemu_sem_post(&multifd_send_state->channels_ready); 798 qemu_sem_post(&p->sem_sync); 799 } 800 } 801 802 static void *multifd_tls_handshake_thread(void *opaque) 803 { 804 MultiFDSendParams *p = opaque; 805 QIOChannelTLS *tioc = QIO_CHANNEL_TLS(p->c); 806 807 qio_channel_tls_handshake(tioc, 808 multifd_tls_outgoing_handshake, 809 p, 810 NULL, 811 NULL); 812 return NULL; 813 } 814 815 static void multifd_tls_channel_connect(MultiFDSendParams *p, 816 QIOChannel *ioc, 817 Error **errp) 818 { 819 MigrationState *s = migrate_get_current(); 820 const char *hostname = s->hostname; 821 QIOChannelTLS *tioc; 822 823 tioc = migration_tls_client_create(ioc, hostname, errp); 824 if (!tioc) { 825 return; 826 } 827 828 object_unref(OBJECT(ioc)); 829 trace_multifd_tls_outgoing_handshake_start(ioc, tioc, hostname); 830 qio_channel_set_name(QIO_CHANNEL(tioc), "multifd-tls-outgoing"); 831 p->c = QIO_CHANNEL(tioc); 832 qemu_thread_create(&p->thread, "multifd-tls-handshake-worker", 833 multifd_tls_handshake_thread, p, 834 QEMU_THREAD_JOINABLE); 835 } 836 837 static bool multifd_channel_connect(MultiFDSendParams *p, 838 QIOChannel *ioc, 839 Error *error) 840 { 841 trace_multifd_set_outgoing_channel( 842 ioc, object_get_typename(OBJECT(ioc)), 843 migrate_get_current()->hostname, error); 844 845 if (error) { 846 return false; 847 } 848 if (migrate_channel_requires_tls_upgrade(ioc)) { 849 multifd_tls_channel_connect(p, ioc, &error); 850 if (!error) { 851 /* 852 * tls_channel_connect will call back to this 853 * function after the TLS handshake, 854 * so we mustn't call multifd_send_thread until then 855 */ 856 return true; 857 } else { 858 return false; 859 } 860 } else { 861 migration_ioc_register_yank(ioc); 862 p->registered_yank = true; 863 p->c = ioc; 864 qemu_thread_create(&p->thread, p->name, multifd_send_thread, p, 865 QEMU_THREAD_JOINABLE); 866 } 867 return true; 868 } 869 870 static void multifd_new_send_channel_cleanup(MultiFDSendParams *p, 871 QIOChannel *ioc, Error *err) 872 { 873 migrate_set_error(migrate_get_current(), err); 874 /* Error happen, we need to tell who pay attention to me */ 875 qemu_sem_post(&multifd_send_state->channels_ready); 876 qemu_sem_post(&p->sem_sync); 877 /* 878 * Although multifd_send_thread is not created, but main migration 879 * thread neet to judge whether it is running, so we need to mark 880 * its status. 881 */ 882 p->quit = true; 883 object_unref(OBJECT(ioc)); 884 error_free(err); 885 } 886 887 static void multifd_new_send_channel_async(QIOTask *task, gpointer opaque) 888 { 889 MultiFDSendParams *p = opaque; 890 QIOChannel *sioc = QIO_CHANNEL(qio_task_get_source(task)); 891 Error *local_err = NULL; 892 893 trace_multifd_new_send_channel_async(p->id); 894 if (!qio_task_propagate_error(task, &local_err)) { 895 p->c = QIO_CHANNEL(sioc); 896 qio_channel_set_delay(p->c, false); 897 p->running = true; 898 if (multifd_channel_connect(p, sioc, local_err)) { 899 return; 900 } 901 } 902 903 multifd_new_send_channel_cleanup(p, sioc, local_err); 904 } 905 906 int multifd_save_setup(Error **errp) 907 { 908 int thread_count; 909 uint32_t page_count = MULTIFD_PACKET_SIZE / qemu_target_page_size(); 910 uint8_t i; 911 912 if (!migrate_multifd()) { 913 return 0; 914 } 915 916 thread_count = migrate_multifd_channels(); 917 multifd_send_state = g_malloc0(sizeof(*multifd_send_state)); 918 multifd_send_state->params = g_new0(MultiFDSendParams, thread_count); 919 multifd_send_state->pages = multifd_pages_init(page_count); 920 qemu_sem_init(&multifd_send_state->channels_ready, 0); 921 qatomic_set(&multifd_send_state->exiting, 0); 922 multifd_send_state->ops = multifd_ops[migrate_multifd_compression()]; 923 924 for (i = 0; i < thread_count; i++) { 925 MultiFDSendParams *p = &multifd_send_state->params[i]; 926 927 qemu_mutex_init(&p->mutex); 928 qemu_sem_init(&p->sem, 0); 929 qemu_sem_init(&p->sem_sync, 0); 930 p->quit = false; 931 p->pending_job = 0; 932 p->id = i; 933 p->pages = multifd_pages_init(page_count); 934 p->packet_len = sizeof(MultiFDPacket_t) 935 + sizeof(uint64_t) * page_count; 936 p->packet = g_malloc0(p->packet_len); 937 p->packet->magic = cpu_to_be32(MULTIFD_MAGIC); 938 p->packet->version = cpu_to_be32(MULTIFD_VERSION); 939 p->name = g_strdup_printf("multifdsend_%d", i); 940 /* We need one extra place for the packet header */ 941 p->iov = g_new0(struct iovec, page_count + 1); 942 p->normal = g_new0(ram_addr_t, page_count); 943 p->page_size = qemu_target_page_size(); 944 p->page_count = page_count; 945 946 if (migrate_zero_copy_send()) { 947 p->write_flags = QIO_CHANNEL_WRITE_FLAG_ZERO_COPY; 948 } else { 949 p->write_flags = 0; 950 } 951 952 socket_send_channel_create(multifd_new_send_channel_async, p); 953 } 954 955 for (i = 0; i < thread_count; i++) { 956 MultiFDSendParams *p = &multifd_send_state->params[i]; 957 Error *local_err = NULL; 958 int ret; 959 960 ret = multifd_send_state->ops->send_setup(p, &local_err); 961 if (ret) { 962 error_propagate(errp, local_err); 963 return ret; 964 } 965 } 966 return 0; 967 } 968 969 struct { 970 MultiFDRecvParams *params; 971 /* number of created threads */ 972 int count; 973 /* syncs main thread and channels */ 974 QemuSemaphore sem_sync; 975 /* global number of generated multifd packets */ 976 uint64_t packet_num; 977 /* multifd ops */ 978 MultiFDMethods *ops; 979 } *multifd_recv_state; 980 981 static void multifd_recv_terminate_threads(Error *err) 982 { 983 int i; 984 985 trace_multifd_recv_terminate_threads(err != NULL); 986 987 if (err) { 988 MigrationState *s = migrate_get_current(); 989 migrate_set_error(s, err); 990 if (s->state == MIGRATION_STATUS_SETUP || 991 s->state == MIGRATION_STATUS_ACTIVE) { 992 migrate_set_state(&s->state, s->state, 993 MIGRATION_STATUS_FAILED); 994 } 995 } 996 997 for (i = 0; i < migrate_multifd_channels(); i++) { 998 MultiFDRecvParams *p = &multifd_recv_state->params[i]; 999 1000 qemu_mutex_lock(&p->mutex); 1001 p->quit = true; 1002 /* 1003 * We could arrive here for two reasons: 1004 * - normal quit, i.e. everything went fine, just finished 1005 * - error quit: We close the channels so the channel threads 1006 * finish the qio_channel_read_all_eof() 1007 */ 1008 if (p->c) { 1009 qio_channel_shutdown(p->c, QIO_CHANNEL_SHUTDOWN_BOTH, NULL); 1010 } 1011 qemu_mutex_unlock(&p->mutex); 1012 } 1013 } 1014 1015 void multifd_load_shutdown(void) 1016 { 1017 if (migrate_multifd()) { 1018 multifd_recv_terminate_threads(NULL); 1019 } 1020 } 1021 1022 void multifd_load_cleanup(void) 1023 { 1024 int i; 1025 1026 if (!migrate_multifd()) { 1027 return; 1028 } 1029 multifd_recv_terminate_threads(NULL); 1030 for (i = 0; i < migrate_multifd_channels(); i++) { 1031 MultiFDRecvParams *p = &multifd_recv_state->params[i]; 1032 1033 if (p->running) { 1034 /* 1035 * multifd_recv_thread may hung at MULTIFD_FLAG_SYNC handle code, 1036 * however try to wakeup it without harm in cleanup phase. 1037 */ 1038 qemu_sem_post(&p->sem_sync); 1039 } 1040 1041 qemu_thread_join(&p->thread); 1042 } 1043 for (i = 0; i < migrate_multifd_channels(); i++) { 1044 MultiFDRecvParams *p = &multifd_recv_state->params[i]; 1045 1046 migration_ioc_unregister_yank(p->c); 1047 object_unref(OBJECT(p->c)); 1048 p->c = NULL; 1049 qemu_mutex_destroy(&p->mutex); 1050 qemu_sem_destroy(&p->sem_sync); 1051 g_free(p->name); 1052 p->name = NULL; 1053 p->packet_len = 0; 1054 g_free(p->packet); 1055 p->packet = NULL; 1056 g_free(p->iov); 1057 p->iov = NULL; 1058 g_free(p->normal); 1059 p->normal = NULL; 1060 multifd_recv_state->ops->recv_cleanup(p); 1061 } 1062 qemu_sem_destroy(&multifd_recv_state->sem_sync); 1063 g_free(multifd_recv_state->params); 1064 multifd_recv_state->params = NULL; 1065 g_free(multifd_recv_state); 1066 multifd_recv_state = NULL; 1067 } 1068 1069 void multifd_recv_sync_main(void) 1070 { 1071 int i; 1072 1073 if (!migrate_multifd()) { 1074 return; 1075 } 1076 for (i = 0; i < migrate_multifd_channels(); i++) { 1077 MultiFDRecvParams *p = &multifd_recv_state->params[i]; 1078 1079 trace_multifd_recv_sync_main_wait(p->id); 1080 qemu_sem_wait(&multifd_recv_state->sem_sync); 1081 } 1082 for (i = 0; i < migrate_multifd_channels(); i++) { 1083 MultiFDRecvParams *p = &multifd_recv_state->params[i]; 1084 1085 WITH_QEMU_LOCK_GUARD(&p->mutex) { 1086 if (multifd_recv_state->packet_num < p->packet_num) { 1087 multifd_recv_state->packet_num = p->packet_num; 1088 } 1089 } 1090 trace_multifd_recv_sync_main_signal(p->id); 1091 qemu_sem_post(&p->sem_sync); 1092 } 1093 trace_multifd_recv_sync_main(multifd_recv_state->packet_num); 1094 } 1095 1096 static void *multifd_recv_thread(void *opaque) 1097 { 1098 MultiFDRecvParams *p = opaque; 1099 Error *local_err = NULL; 1100 int ret; 1101 1102 trace_multifd_recv_thread_start(p->id); 1103 rcu_register_thread(); 1104 1105 while (true) { 1106 uint32_t flags; 1107 1108 if (p->quit) { 1109 break; 1110 } 1111 1112 ret = qio_channel_read_all_eof(p->c, (void *)p->packet, 1113 p->packet_len, &local_err); 1114 if (ret == 0 || ret == -1) { /* 0: EOF -1: Error */ 1115 break; 1116 } 1117 1118 qemu_mutex_lock(&p->mutex); 1119 ret = multifd_recv_unfill_packet(p, &local_err); 1120 if (ret) { 1121 qemu_mutex_unlock(&p->mutex); 1122 break; 1123 } 1124 1125 flags = p->flags; 1126 /* recv methods don't know how to handle the SYNC flag */ 1127 p->flags &= ~MULTIFD_FLAG_SYNC; 1128 trace_multifd_recv(p->id, p->packet_num, p->normal_num, flags, 1129 p->next_packet_size); 1130 p->num_packets++; 1131 p->total_normal_pages += p->normal_num; 1132 qemu_mutex_unlock(&p->mutex); 1133 1134 if (p->normal_num) { 1135 ret = multifd_recv_state->ops->recv_pages(p, &local_err); 1136 if (ret != 0) { 1137 break; 1138 } 1139 } 1140 1141 if (flags & MULTIFD_FLAG_SYNC) { 1142 qemu_sem_post(&multifd_recv_state->sem_sync); 1143 qemu_sem_wait(&p->sem_sync); 1144 } 1145 } 1146 1147 if (local_err) { 1148 multifd_recv_terminate_threads(local_err); 1149 error_free(local_err); 1150 } 1151 qemu_mutex_lock(&p->mutex); 1152 p->running = false; 1153 qemu_mutex_unlock(&p->mutex); 1154 1155 rcu_unregister_thread(); 1156 trace_multifd_recv_thread_end(p->id, p->num_packets, p->total_normal_pages); 1157 1158 return NULL; 1159 } 1160 1161 int multifd_load_setup(Error **errp) 1162 { 1163 int thread_count; 1164 uint32_t page_count = MULTIFD_PACKET_SIZE / qemu_target_page_size(); 1165 uint8_t i; 1166 1167 /* 1168 * Return successfully if multiFD recv state is already initialised 1169 * or multiFD is not enabled. 1170 */ 1171 if (multifd_recv_state || !migrate_multifd()) { 1172 return 0; 1173 } 1174 1175 thread_count = migrate_multifd_channels(); 1176 multifd_recv_state = g_malloc0(sizeof(*multifd_recv_state)); 1177 multifd_recv_state->params = g_new0(MultiFDRecvParams, thread_count); 1178 qatomic_set(&multifd_recv_state->count, 0); 1179 qemu_sem_init(&multifd_recv_state->sem_sync, 0); 1180 multifd_recv_state->ops = multifd_ops[migrate_multifd_compression()]; 1181 1182 for (i = 0; i < thread_count; i++) { 1183 MultiFDRecvParams *p = &multifd_recv_state->params[i]; 1184 1185 qemu_mutex_init(&p->mutex); 1186 qemu_sem_init(&p->sem_sync, 0); 1187 p->quit = false; 1188 p->id = i; 1189 p->packet_len = sizeof(MultiFDPacket_t) 1190 + sizeof(uint64_t) * page_count; 1191 p->packet = g_malloc0(p->packet_len); 1192 p->name = g_strdup_printf("multifdrecv_%d", i); 1193 p->iov = g_new0(struct iovec, page_count); 1194 p->normal = g_new0(ram_addr_t, page_count); 1195 p->page_count = page_count; 1196 p->page_size = qemu_target_page_size(); 1197 } 1198 1199 for (i = 0; i < thread_count; i++) { 1200 MultiFDRecvParams *p = &multifd_recv_state->params[i]; 1201 Error *local_err = NULL; 1202 int ret; 1203 1204 ret = multifd_recv_state->ops->recv_setup(p, &local_err); 1205 if (ret) { 1206 error_propagate(errp, local_err); 1207 return ret; 1208 } 1209 } 1210 return 0; 1211 } 1212 1213 bool multifd_recv_all_channels_created(void) 1214 { 1215 int thread_count = migrate_multifd_channels(); 1216 1217 if (!migrate_multifd()) { 1218 return true; 1219 } 1220 1221 if (!multifd_recv_state) { 1222 /* Called before any connections created */ 1223 return false; 1224 } 1225 1226 return thread_count == qatomic_read(&multifd_recv_state->count); 1227 } 1228 1229 /* 1230 * Try to receive all multifd channels to get ready for the migration. 1231 * Sets @errp when failing to receive the current channel. 1232 */ 1233 void multifd_recv_new_channel(QIOChannel *ioc, Error **errp) 1234 { 1235 MultiFDRecvParams *p; 1236 Error *local_err = NULL; 1237 int id; 1238 1239 id = multifd_recv_initial_packet(ioc, &local_err); 1240 if (id < 0) { 1241 multifd_recv_terminate_threads(local_err); 1242 error_propagate_prepend(errp, local_err, 1243 "failed to receive packet" 1244 " via multifd channel %d: ", 1245 qatomic_read(&multifd_recv_state->count)); 1246 return; 1247 } 1248 trace_multifd_recv_new_channel(id); 1249 1250 p = &multifd_recv_state->params[id]; 1251 if (p->c != NULL) { 1252 error_setg(&local_err, "multifd: received id '%d' already setup'", 1253 id); 1254 multifd_recv_terminate_threads(local_err); 1255 error_propagate(errp, local_err); 1256 return; 1257 } 1258 p->c = ioc; 1259 object_ref(OBJECT(ioc)); 1260 /* initial packet */ 1261 p->num_packets = 1; 1262 1263 p->running = true; 1264 qemu_thread_create(&p->thread, p->name, multifd_recv_thread, p, 1265 QEMU_THREAD_JOINABLE); 1266 qatomic_inc(&multifd_recv_state->count); 1267 } 1268