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 size_t size = sizeof(msg); 179 int ret; 180 181 msg.magic = cpu_to_be32(MULTIFD_MAGIC); 182 msg.version = cpu_to_be32(MULTIFD_VERSION); 183 msg.id = p->id; 184 memcpy(msg.uuid, &qemu_uuid.data, sizeof(msg.uuid)); 185 186 ret = qio_channel_write_all(p->c, (char *)&msg, size, errp); 187 if (ret != 0) { 188 return -1; 189 } 190 stat64_add(&mig_stats.multifd_bytes, size); 191 stat64_add(&mig_stats.transferred, size); 192 return 0; 193 } 194 195 static int multifd_recv_initial_packet(QIOChannel *c, Error **errp) 196 { 197 MultiFDInit_t msg; 198 int ret; 199 200 ret = qio_channel_read_all(c, (char *)&msg, sizeof(msg), errp); 201 if (ret != 0) { 202 return -1; 203 } 204 205 msg.magic = be32_to_cpu(msg.magic); 206 msg.version = be32_to_cpu(msg.version); 207 208 if (msg.magic != MULTIFD_MAGIC) { 209 error_setg(errp, "multifd: received packet magic %x " 210 "expected %x", msg.magic, MULTIFD_MAGIC); 211 return -1; 212 } 213 214 if (msg.version != MULTIFD_VERSION) { 215 error_setg(errp, "multifd: received packet version %u " 216 "expected %u", msg.version, MULTIFD_VERSION); 217 return -1; 218 } 219 220 if (memcmp(msg.uuid, &qemu_uuid, sizeof(qemu_uuid))) { 221 char *uuid = qemu_uuid_unparse_strdup(&qemu_uuid); 222 char *msg_uuid = qemu_uuid_unparse_strdup((const QemuUUID *)msg.uuid); 223 224 error_setg(errp, "multifd: received uuid '%s' and expected " 225 "uuid '%s' for channel %hhd", msg_uuid, uuid, msg.id); 226 g_free(uuid); 227 g_free(msg_uuid); 228 return -1; 229 } 230 231 if (msg.id > migrate_multifd_channels()) { 232 error_setg(errp, "multifd: received channel version %u " 233 "expected %u", msg.version, MULTIFD_VERSION); 234 return -1; 235 } 236 237 return msg.id; 238 } 239 240 static MultiFDPages_t *multifd_pages_init(size_t size) 241 { 242 MultiFDPages_t *pages = g_new0(MultiFDPages_t, 1); 243 244 pages->allocated = size; 245 pages->offset = g_new0(ram_addr_t, size); 246 247 return pages; 248 } 249 250 static void multifd_pages_clear(MultiFDPages_t *pages) 251 { 252 pages->num = 0; 253 pages->allocated = 0; 254 pages->packet_num = 0; 255 pages->block = NULL; 256 g_free(pages->offset); 257 pages->offset = NULL; 258 g_free(pages); 259 } 260 261 static void multifd_send_fill_packet(MultiFDSendParams *p) 262 { 263 MultiFDPacket_t *packet = p->packet; 264 int i; 265 266 packet->flags = cpu_to_be32(p->flags); 267 packet->pages_alloc = cpu_to_be32(p->pages->allocated); 268 packet->normal_pages = cpu_to_be32(p->normal_num); 269 packet->next_packet_size = cpu_to_be32(p->next_packet_size); 270 packet->packet_num = cpu_to_be64(p->packet_num); 271 272 if (p->pages->block) { 273 strncpy(packet->ramblock, p->pages->block->idstr, 256); 274 } 275 276 for (i = 0; i < p->normal_num; i++) { 277 /* there are architectures where ram_addr_t is 32 bit */ 278 uint64_t temp = p->normal[i]; 279 280 packet->offset[i] = cpu_to_be64(temp); 281 } 282 } 283 284 static int multifd_recv_unfill_packet(MultiFDRecvParams *p, Error **errp) 285 { 286 MultiFDPacket_t *packet = p->packet; 287 int i; 288 289 packet->magic = be32_to_cpu(packet->magic); 290 if (packet->magic != MULTIFD_MAGIC) { 291 error_setg(errp, "multifd: received packet " 292 "magic %x and expected magic %x", 293 packet->magic, MULTIFD_MAGIC); 294 return -1; 295 } 296 297 packet->version = be32_to_cpu(packet->version); 298 if (packet->version != MULTIFD_VERSION) { 299 error_setg(errp, "multifd: received packet " 300 "version %u and expected version %u", 301 packet->version, MULTIFD_VERSION); 302 return -1; 303 } 304 305 p->flags = be32_to_cpu(packet->flags); 306 307 packet->pages_alloc = be32_to_cpu(packet->pages_alloc); 308 /* 309 * If we received a packet that is 100 times bigger than expected 310 * just stop migration. It is a magic number. 311 */ 312 if (packet->pages_alloc > p->page_count) { 313 error_setg(errp, "multifd: received packet " 314 "with size %u and expected a size of %u", 315 packet->pages_alloc, p->page_count) ; 316 return -1; 317 } 318 319 p->normal_num = be32_to_cpu(packet->normal_pages); 320 if (p->normal_num > packet->pages_alloc) { 321 error_setg(errp, "multifd: received packet " 322 "with %u pages and expected maximum pages are %u", 323 p->normal_num, packet->pages_alloc) ; 324 return -1; 325 } 326 327 p->next_packet_size = be32_to_cpu(packet->next_packet_size); 328 p->packet_num = be64_to_cpu(packet->packet_num); 329 330 if (p->normal_num == 0) { 331 return 0; 332 } 333 334 /* make sure that ramblock is 0 terminated */ 335 packet->ramblock[255] = 0; 336 p->block = qemu_ram_block_by_name(packet->ramblock); 337 if (!p->block) { 338 error_setg(errp, "multifd: unknown ram block %s", 339 packet->ramblock); 340 return -1; 341 } 342 343 p->host = p->block->host; 344 for (i = 0; i < p->normal_num; i++) { 345 uint64_t offset = be64_to_cpu(packet->offset[i]); 346 347 if (offset > (p->block->used_length - p->page_size)) { 348 error_setg(errp, "multifd: offset too long %" PRIu64 349 " (max " RAM_ADDR_FMT ")", 350 offset, p->block->used_length); 351 return -1; 352 } 353 p->normal[i] = offset; 354 } 355 356 return 0; 357 } 358 359 struct { 360 MultiFDSendParams *params; 361 /* array of pages to sent */ 362 MultiFDPages_t *pages; 363 /* global number of generated multifd packets */ 364 uint64_t packet_num; 365 /* send channels ready */ 366 QemuSemaphore channels_ready; 367 /* 368 * Have we already run terminate threads. There is a race when it 369 * happens that we got one error while we are exiting. 370 * We will use atomic operations. Only valid values are 0 and 1. 371 */ 372 int exiting; 373 /* multifd ops */ 374 MultiFDMethods *ops; 375 } *multifd_send_state; 376 377 /* 378 * How we use multifd_send_state->pages and channel->pages? 379 * 380 * We create a pages for each channel, and a main one. Each time that 381 * we need to send a batch of pages we interchange the ones between 382 * multifd_send_state and the channel that is sending it. There are 383 * two reasons for that: 384 * - to not have to do so many mallocs during migration 385 * - to make easier to know what to free at the end of migration 386 * 387 * This way we always know who is the owner of each "pages" struct, 388 * and we don't need any locking. It belongs to the migration thread 389 * or to the channel thread. Switching is safe because the migration 390 * thread is using the channel mutex when changing it, and the channel 391 * have to had finish with its own, otherwise pending_job can't be 392 * false. 393 */ 394 395 static int multifd_send_pages(QEMUFile *f) 396 { 397 int i; 398 static int next_channel; 399 MultiFDSendParams *p = NULL; /* make happy gcc */ 400 MultiFDPages_t *pages = multifd_send_state->pages; 401 402 if (qatomic_read(&multifd_send_state->exiting)) { 403 return -1; 404 } 405 406 qemu_sem_wait(&multifd_send_state->channels_ready); 407 /* 408 * next_channel can remain from a previous migration that was 409 * using more channels, so ensure it doesn't overflow if the 410 * limit is lower now. 411 */ 412 next_channel %= migrate_multifd_channels(); 413 for (i = next_channel;; i = (i + 1) % migrate_multifd_channels()) { 414 p = &multifd_send_state->params[i]; 415 416 qemu_mutex_lock(&p->mutex); 417 if (p->quit) { 418 error_report("%s: channel %d has already quit!", __func__, i); 419 qemu_mutex_unlock(&p->mutex); 420 return -1; 421 } 422 if (!p->pending_job) { 423 p->pending_job++; 424 next_channel = (i + 1) % migrate_multifd_channels(); 425 break; 426 } 427 qemu_mutex_unlock(&p->mutex); 428 } 429 assert(!p->pages->num); 430 assert(!p->pages->block); 431 432 p->packet_num = multifd_send_state->packet_num++; 433 multifd_send_state->pages = p->pages; 434 p->pages = pages; 435 qemu_mutex_unlock(&p->mutex); 436 qemu_sem_post(&p->sem); 437 438 return 1; 439 } 440 441 int multifd_queue_page(QEMUFile *f, RAMBlock *block, ram_addr_t offset) 442 { 443 MultiFDPages_t *pages = multifd_send_state->pages; 444 bool changed = false; 445 446 if (!pages->block) { 447 pages->block = block; 448 } 449 450 if (pages->block == block) { 451 pages->offset[pages->num] = offset; 452 pages->num++; 453 454 if (pages->num < pages->allocated) { 455 return 1; 456 } 457 } else { 458 changed = true; 459 } 460 461 if (multifd_send_pages(f) < 0) { 462 return -1; 463 } 464 465 if (changed) { 466 return multifd_queue_page(f, block, offset); 467 } 468 469 return 1; 470 } 471 472 static void multifd_send_terminate_threads(Error *err) 473 { 474 int i; 475 476 trace_multifd_send_terminate_threads(err != NULL); 477 478 if (err) { 479 MigrationState *s = migrate_get_current(); 480 migrate_set_error(s, err); 481 if (s->state == MIGRATION_STATUS_SETUP || 482 s->state == MIGRATION_STATUS_PRE_SWITCHOVER || 483 s->state == MIGRATION_STATUS_DEVICE || 484 s->state == MIGRATION_STATUS_ACTIVE) { 485 migrate_set_state(&s->state, s->state, 486 MIGRATION_STATUS_FAILED); 487 } 488 } 489 490 /* 491 * We don't want to exit each threads twice. Depending on where 492 * we get the error, or if there are two independent errors in two 493 * threads at the same time, we can end calling this function 494 * twice. 495 */ 496 if (qatomic_xchg(&multifd_send_state->exiting, 1)) { 497 return; 498 } 499 500 for (i = 0; i < migrate_multifd_channels(); i++) { 501 MultiFDSendParams *p = &multifd_send_state->params[i]; 502 503 qemu_mutex_lock(&p->mutex); 504 p->quit = true; 505 qemu_sem_post(&p->sem); 506 if (p->c) { 507 qio_channel_shutdown(p->c, QIO_CHANNEL_SHUTDOWN_BOTH, NULL); 508 } 509 qemu_mutex_unlock(&p->mutex); 510 } 511 } 512 513 static int multifd_send_channel_destroy(QIOChannel *send) 514 { 515 return socket_send_channel_destroy(send); 516 } 517 518 void multifd_save_cleanup(void) 519 { 520 int i; 521 522 if (!migrate_multifd()) { 523 return; 524 } 525 multifd_send_terminate_threads(NULL); 526 for (i = 0; i < migrate_multifd_channels(); i++) { 527 MultiFDSendParams *p = &multifd_send_state->params[i]; 528 529 if (p->running) { 530 qemu_thread_join(&p->thread); 531 } 532 } 533 for (i = 0; i < migrate_multifd_channels(); i++) { 534 MultiFDSendParams *p = &multifd_send_state->params[i]; 535 Error *local_err = NULL; 536 537 if (p->registered_yank) { 538 migration_ioc_unregister_yank(p->c); 539 } 540 multifd_send_channel_destroy(p->c); 541 p->c = NULL; 542 qemu_mutex_destroy(&p->mutex); 543 qemu_sem_destroy(&p->sem); 544 qemu_sem_destroy(&p->sem_sync); 545 g_free(p->name); 546 p->name = NULL; 547 multifd_pages_clear(p->pages); 548 p->pages = NULL; 549 p->packet_len = 0; 550 g_free(p->packet); 551 p->packet = NULL; 552 g_free(p->iov); 553 p->iov = NULL; 554 g_free(p->normal); 555 p->normal = NULL; 556 multifd_send_state->ops->send_cleanup(p, &local_err); 557 if (local_err) { 558 migrate_set_error(migrate_get_current(), local_err); 559 error_free(local_err); 560 } 561 } 562 qemu_sem_destroy(&multifd_send_state->channels_ready); 563 g_free(multifd_send_state->params); 564 multifd_send_state->params = NULL; 565 multifd_pages_clear(multifd_send_state->pages); 566 multifd_send_state->pages = NULL; 567 g_free(multifd_send_state); 568 multifd_send_state = NULL; 569 } 570 571 static int multifd_zero_copy_flush(QIOChannel *c) 572 { 573 int ret; 574 Error *err = NULL; 575 576 ret = qio_channel_flush(c, &err); 577 if (ret < 0) { 578 error_report_err(err); 579 return -1; 580 } 581 if (ret == 1) { 582 stat64_add(&mig_stats.dirty_sync_missed_zero_copy, 1); 583 } 584 585 return ret; 586 } 587 588 int multifd_send_sync_main(QEMUFile *f) 589 { 590 int i; 591 bool flush_zero_copy; 592 593 if (!migrate_multifd()) { 594 return 0; 595 } 596 if (multifd_send_state->pages->num) { 597 if (multifd_send_pages(f) < 0) { 598 error_report("%s: multifd_send_pages fail", __func__); 599 return -1; 600 } 601 } 602 603 /* 604 * When using zero-copy, it's necessary to flush the pages before any of 605 * the pages can be sent again, so we'll make sure the new version of the 606 * pages will always arrive _later_ than the old pages. 607 * 608 * Currently we achieve this by flushing the zero-page requested writes 609 * per ram iteration, but in the future we could potentially optimize it 610 * to be less frequent, e.g. only after we finished one whole scanning of 611 * all the dirty bitmaps. 612 */ 613 614 flush_zero_copy = migrate_zero_copy_send(); 615 616 for (i = 0; i < migrate_multifd_channels(); i++) { 617 MultiFDSendParams *p = &multifd_send_state->params[i]; 618 619 trace_multifd_send_sync_main_signal(p->id); 620 621 qemu_mutex_lock(&p->mutex); 622 623 if (p->quit) { 624 error_report("%s: channel %d has already quit", __func__, i); 625 qemu_mutex_unlock(&p->mutex); 626 return -1; 627 } 628 629 p->packet_num = multifd_send_state->packet_num++; 630 p->flags |= MULTIFD_FLAG_SYNC; 631 p->pending_job++; 632 qemu_mutex_unlock(&p->mutex); 633 qemu_sem_post(&p->sem); 634 } 635 for (i = 0; i < migrate_multifd_channels(); i++) { 636 MultiFDSendParams *p = &multifd_send_state->params[i]; 637 638 qemu_sem_wait(&multifd_send_state->channels_ready); 639 trace_multifd_send_sync_main_wait(p->id); 640 qemu_sem_wait(&p->sem_sync); 641 642 if (flush_zero_copy && p->c && (multifd_zero_copy_flush(p->c) < 0)) { 643 return -1; 644 } 645 } 646 trace_multifd_send_sync_main(multifd_send_state->packet_num); 647 648 return 0; 649 } 650 651 static void *multifd_send_thread(void *opaque) 652 { 653 MultiFDSendParams *p = opaque; 654 MigrationThread *thread = NULL; 655 Error *local_err = NULL; 656 int ret = 0; 657 bool use_zero_copy_send = migrate_zero_copy_send(); 658 659 thread = migration_threads_add(p->name, qemu_get_thread_id()); 660 661 trace_multifd_send_thread_start(p->id); 662 rcu_register_thread(); 663 664 if (multifd_send_initial_packet(p, &local_err) < 0) { 665 ret = -1; 666 goto out; 667 } 668 /* initial packet */ 669 p->num_packets = 1; 670 671 while (true) { 672 qemu_sem_post(&multifd_send_state->channels_ready); 673 qemu_sem_wait(&p->sem); 674 675 if (qatomic_read(&multifd_send_state->exiting)) { 676 break; 677 } 678 qemu_mutex_lock(&p->mutex); 679 680 if (p->pending_job) { 681 uint64_t packet_num = p->packet_num; 682 uint32_t flags; 683 p->normal_num = 0; 684 685 if (use_zero_copy_send) { 686 p->iovs_num = 0; 687 } else { 688 p->iovs_num = 1; 689 } 690 691 for (int i = 0; i < p->pages->num; i++) { 692 p->normal[p->normal_num] = p->pages->offset[i]; 693 p->normal_num++; 694 } 695 696 if (p->normal_num) { 697 ret = multifd_send_state->ops->send_prepare(p, &local_err); 698 if (ret != 0) { 699 qemu_mutex_unlock(&p->mutex); 700 break; 701 } 702 } 703 multifd_send_fill_packet(p); 704 flags = p->flags; 705 p->flags = 0; 706 p->num_packets++; 707 p->total_normal_pages += p->normal_num; 708 p->pages->num = 0; 709 p->pages->block = NULL; 710 qemu_mutex_unlock(&p->mutex); 711 712 trace_multifd_send(p->id, packet_num, p->normal_num, flags, 713 p->next_packet_size); 714 715 if (use_zero_copy_send) { 716 /* Send header first, without zerocopy */ 717 ret = qio_channel_write_all(p->c, (void *)p->packet, 718 p->packet_len, &local_err); 719 if (ret != 0) { 720 break; 721 } 722 } else { 723 /* Send header using the same writev call */ 724 p->iov[0].iov_len = p->packet_len; 725 p->iov[0].iov_base = p->packet; 726 } 727 728 ret = qio_channel_writev_full_all(p->c, p->iov, p->iovs_num, NULL, 729 0, p->write_flags, &local_err); 730 if (ret != 0) { 731 break; 732 } 733 734 stat64_add(&mig_stats.multifd_bytes, 735 p->next_packet_size + p->packet_len); 736 stat64_add(&mig_stats.transferred, 737 p->next_packet_size + p->packet_len); 738 p->next_packet_size = 0; 739 qemu_mutex_lock(&p->mutex); 740 p->pending_job--; 741 qemu_mutex_unlock(&p->mutex); 742 743 if (flags & MULTIFD_FLAG_SYNC) { 744 qemu_sem_post(&p->sem_sync); 745 } 746 } else if (p->quit) { 747 qemu_mutex_unlock(&p->mutex); 748 break; 749 } else { 750 qemu_mutex_unlock(&p->mutex); 751 /* sometimes there are spurious wakeups */ 752 } 753 } 754 755 out: 756 if (ret) { 757 assert(local_err); 758 trace_multifd_send_error(p->id); 759 multifd_send_terminate_threads(local_err); 760 qemu_sem_post(&p->sem_sync); 761 qemu_sem_post(&multifd_send_state->channels_ready); 762 error_free(local_err); 763 } 764 765 qemu_mutex_lock(&p->mutex); 766 p->running = false; 767 qemu_mutex_unlock(&p->mutex); 768 769 rcu_unregister_thread(); 770 migration_threads_remove(thread); 771 trace_multifd_send_thread_end(p->id, p->num_packets, p->total_normal_pages); 772 773 return NULL; 774 } 775 776 static bool multifd_channel_connect(MultiFDSendParams *p, 777 QIOChannel *ioc, 778 Error **errp); 779 780 static void multifd_tls_outgoing_handshake(QIOTask *task, 781 gpointer opaque) 782 { 783 MultiFDSendParams *p = opaque; 784 QIOChannel *ioc = QIO_CHANNEL(qio_task_get_source(task)); 785 Error *err = NULL; 786 787 if (!qio_task_propagate_error(task, &err)) { 788 trace_multifd_tls_outgoing_handshake_complete(ioc); 789 if (multifd_channel_connect(p, ioc, &err)) { 790 return; 791 } 792 } 793 794 trace_multifd_tls_outgoing_handshake_error(ioc, error_get_pretty(err)); 795 796 /* 797 * Error happen, mark multifd_send_thread status as 'quit' although it 798 * is not created, and then tell who pay attention to me. 799 */ 800 p->quit = true; 801 qemu_sem_post(&multifd_send_state->channels_ready); 802 qemu_sem_post(&p->sem_sync); 803 } 804 805 static void *multifd_tls_handshake_thread(void *opaque) 806 { 807 MultiFDSendParams *p = opaque; 808 QIOChannelTLS *tioc = QIO_CHANNEL_TLS(p->c); 809 810 qio_channel_tls_handshake(tioc, 811 multifd_tls_outgoing_handshake, 812 p, 813 NULL, 814 NULL); 815 return NULL; 816 } 817 818 static bool multifd_tls_channel_connect(MultiFDSendParams *p, 819 QIOChannel *ioc, 820 Error **errp) 821 { 822 MigrationState *s = migrate_get_current(); 823 const char *hostname = s->hostname; 824 QIOChannelTLS *tioc; 825 826 tioc = migration_tls_client_create(ioc, hostname, errp); 827 if (!tioc) { 828 return false; 829 } 830 831 object_unref(OBJECT(ioc)); 832 trace_multifd_tls_outgoing_handshake_start(ioc, tioc, hostname); 833 qio_channel_set_name(QIO_CHANNEL(tioc), "multifd-tls-outgoing"); 834 p->c = QIO_CHANNEL(tioc); 835 qemu_thread_create(&p->thread, "multifd-tls-handshake-worker", 836 multifd_tls_handshake_thread, p, 837 QEMU_THREAD_JOINABLE); 838 return true; 839 } 840 841 static bool multifd_channel_connect(MultiFDSendParams *p, 842 QIOChannel *ioc, 843 Error **errp) 844 { 845 trace_multifd_set_outgoing_channel( 846 ioc, object_get_typename(OBJECT(ioc)), 847 migrate_get_current()->hostname); 848 849 if (migrate_channel_requires_tls_upgrade(ioc)) { 850 /* 851 * tls_channel_connect will call back to this 852 * function after the TLS handshake, 853 * so we mustn't call multifd_send_thread until then 854 */ 855 return multifd_tls_channel_connect(p, ioc, errp); 856 857 } else { 858 migration_ioc_register_yank(ioc); 859 p->registered_yank = true; 860 p->c = ioc; 861 qemu_thread_create(&p->thread, p->name, multifd_send_thread, p, 862 QEMU_THREAD_JOINABLE); 863 } 864 return true; 865 } 866 867 static void multifd_new_send_channel_cleanup(MultiFDSendParams *p, 868 QIOChannel *ioc, Error *err) 869 { 870 migrate_set_error(migrate_get_current(), err); 871 /* Error happen, we need to tell who pay attention to me */ 872 qemu_sem_post(&multifd_send_state->channels_ready); 873 qemu_sem_post(&p->sem_sync); 874 /* 875 * Although multifd_send_thread is not created, but main migration 876 * thread need to judge whether it is running, so we need to mark 877 * its status. 878 */ 879 p->quit = true; 880 object_unref(OBJECT(ioc)); 881 error_free(err); 882 } 883 884 static void multifd_new_send_channel_async(QIOTask *task, gpointer opaque) 885 { 886 MultiFDSendParams *p = opaque; 887 QIOChannel *ioc = QIO_CHANNEL(qio_task_get_source(task)); 888 Error *local_err = NULL; 889 890 trace_multifd_new_send_channel_async(p->id); 891 if (!qio_task_propagate_error(task, &local_err)) { 892 p->c = ioc; 893 qio_channel_set_delay(p->c, false); 894 p->running = true; 895 if (multifd_channel_connect(p, ioc, &local_err)) { 896 return; 897 } 898 } 899 900 trace_multifd_new_send_channel_async_error(p->id, local_err); 901 multifd_new_send_channel_cleanup(p, ioc, local_err); 902 } 903 904 static void multifd_new_send_channel_create(gpointer opaque) 905 { 906 socket_send_channel_create(multifd_new_send_channel_async, opaque); 907 } 908 909 int multifd_save_setup(Error **errp) 910 { 911 int thread_count; 912 uint32_t page_count = MULTIFD_PACKET_SIZE / qemu_target_page_size(); 913 uint8_t i; 914 915 if (!migrate_multifd()) { 916 return 0; 917 } 918 919 thread_count = migrate_multifd_channels(); 920 multifd_send_state = g_malloc0(sizeof(*multifd_send_state)); 921 multifd_send_state->params = g_new0(MultiFDSendParams, thread_count); 922 multifd_send_state->pages = multifd_pages_init(page_count); 923 qemu_sem_init(&multifd_send_state->channels_ready, 0); 924 qatomic_set(&multifd_send_state->exiting, 0); 925 multifd_send_state->ops = multifd_ops[migrate_multifd_compression()]; 926 927 for (i = 0; i < thread_count; i++) { 928 MultiFDSendParams *p = &multifd_send_state->params[i]; 929 930 qemu_mutex_init(&p->mutex); 931 qemu_sem_init(&p->sem, 0); 932 qemu_sem_init(&p->sem_sync, 0); 933 p->quit = false; 934 p->pending_job = 0; 935 p->id = i; 936 p->pages = multifd_pages_init(page_count); 937 p->packet_len = sizeof(MultiFDPacket_t) 938 + sizeof(uint64_t) * page_count; 939 p->packet = g_malloc0(p->packet_len); 940 p->packet->magic = cpu_to_be32(MULTIFD_MAGIC); 941 p->packet->version = cpu_to_be32(MULTIFD_VERSION); 942 p->name = g_strdup_printf("multifdsend_%d", i); 943 /* We need one extra place for the packet header */ 944 p->iov = g_new0(struct iovec, page_count + 1); 945 p->normal = g_new0(ram_addr_t, page_count); 946 p->page_size = qemu_target_page_size(); 947 p->page_count = page_count; 948 949 if (migrate_zero_copy_send()) { 950 p->write_flags = QIO_CHANNEL_WRITE_FLAG_ZERO_COPY; 951 } else { 952 p->write_flags = 0; 953 } 954 955 multifd_new_send_channel_create(p); 956 } 957 958 for (i = 0; i < thread_count; i++) { 959 MultiFDSendParams *p = &multifd_send_state->params[i]; 960 Error *local_err = NULL; 961 int ret; 962 963 ret = multifd_send_state->ops->send_setup(p, &local_err); 964 if (ret) { 965 error_propagate(errp, local_err); 966 return ret; 967 } 968 } 969 return 0; 970 } 971 972 struct { 973 MultiFDRecvParams *params; 974 /* number of created threads */ 975 int count; 976 /* syncs main thread and channels */ 977 QemuSemaphore sem_sync; 978 /* global number of generated multifd packets */ 979 uint64_t packet_num; 980 /* multifd ops */ 981 MultiFDMethods *ops; 982 } *multifd_recv_state; 983 984 static void multifd_recv_terminate_threads(Error *err) 985 { 986 int i; 987 988 trace_multifd_recv_terminate_threads(err != NULL); 989 990 if (err) { 991 MigrationState *s = migrate_get_current(); 992 migrate_set_error(s, err); 993 if (s->state == MIGRATION_STATUS_SETUP || 994 s->state == MIGRATION_STATUS_ACTIVE) { 995 migrate_set_state(&s->state, s->state, 996 MIGRATION_STATUS_FAILED); 997 } 998 } 999 1000 for (i = 0; i < migrate_multifd_channels(); i++) { 1001 MultiFDRecvParams *p = &multifd_recv_state->params[i]; 1002 1003 qemu_mutex_lock(&p->mutex); 1004 p->quit = true; 1005 /* 1006 * We could arrive here for two reasons: 1007 * - normal quit, i.e. everything went fine, just finished 1008 * - error quit: We close the channels so the channel threads 1009 * finish the qio_channel_read_all_eof() 1010 */ 1011 if (p->c) { 1012 qio_channel_shutdown(p->c, QIO_CHANNEL_SHUTDOWN_BOTH, NULL); 1013 } 1014 qemu_mutex_unlock(&p->mutex); 1015 } 1016 } 1017 1018 void multifd_load_shutdown(void) 1019 { 1020 if (migrate_multifd()) { 1021 multifd_recv_terminate_threads(NULL); 1022 } 1023 } 1024 1025 void multifd_load_cleanup(void) 1026 { 1027 int i; 1028 1029 if (!migrate_multifd()) { 1030 return; 1031 } 1032 multifd_recv_terminate_threads(NULL); 1033 for (i = 0; i < migrate_multifd_channels(); i++) { 1034 MultiFDRecvParams *p = &multifd_recv_state->params[i]; 1035 1036 if (p->running) { 1037 /* 1038 * multifd_recv_thread may hung at MULTIFD_FLAG_SYNC handle code, 1039 * however try to wakeup it without harm in cleanup phase. 1040 */ 1041 qemu_sem_post(&p->sem_sync); 1042 } 1043 1044 qemu_thread_join(&p->thread); 1045 } 1046 for (i = 0; i < migrate_multifd_channels(); i++) { 1047 MultiFDRecvParams *p = &multifd_recv_state->params[i]; 1048 1049 migration_ioc_unregister_yank(p->c); 1050 object_unref(OBJECT(p->c)); 1051 p->c = NULL; 1052 qemu_mutex_destroy(&p->mutex); 1053 qemu_sem_destroy(&p->sem_sync); 1054 g_free(p->name); 1055 p->name = NULL; 1056 p->packet_len = 0; 1057 g_free(p->packet); 1058 p->packet = NULL; 1059 g_free(p->iov); 1060 p->iov = NULL; 1061 g_free(p->normal); 1062 p->normal = NULL; 1063 multifd_recv_state->ops->recv_cleanup(p); 1064 } 1065 qemu_sem_destroy(&multifd_recv_state->sem_sync); 1066 g_free(multifd_recv_state->params); 1067 multifd_recv_state->params = NULL; 1068 g_free(multifd_recv_state); 1069 multifd_recv_state = NULL; 1070 } 1071 1072 void multifd_recv_sync_main(void) 1073 { 1074 int i; 1075 1076 if (!migrate_multifd()) { 1077 return; 1078 } 1079 for (i = 0; i < migrate_multifd_channels(); i++) { 1080 MultiFDRecvParams *p = &multifd_recv_state->params[i]; 1081 1082 trace_multifd_recv_sync_main_wait(p->id); 1083 qemu_sem_wait(&multifd_recv_state->sem_sync); 1084 } 1085 for (i = 0; i < migrate_multifd_channels(); i++) { 1086 MultiFDRecvParams *p = &multifd_recv_state->params[i]; 1087 1088 WITH_QEMU_LOCK_GUARD(&p->mutex) { 1089 if (multifd_recv_state->packet_num < p->packet_num) { 1090 multifd_recv_state->packet_num = p->packet_num; 1091 } 1092 } 1093 trace_multifd_recv_sync_main_signal(p->id); 1094 qemu_sem_post(&p->sem_sync); 1095 } 1096 trace_multifd_recv_sync_main(multifd_recv_state->packet_num); 1097 } 1098 1099 static void *multifd_recv_thread(void *opaque) 1100 { 1101 MultiFDRecvParams *p = opaque; 1102 Error *local_err = NULL; 1103 int ret; 1104 1105 trace_multifd_recv_thread_start(p->id); 1106 rcu_register_thread(); 1107 1108 while (true) { 1109 uint32_t flags; 1110 1111 if (p->quit) { 1112 break; 1113 } 1114 1115 ret = qio_channel_read_all_eof(p->c, (void *)p->packet, 1116 p->packet_len, &local_err); 1117 if (ret == 0 || ret == -1) { /* 0: EOF -1: Error */ 1118 break; 1119 } 1120 1121 qemu_mutex_lock(&p->mutex); 1122 ret = multifd_recv_unfill_packet(p, &local_err); 1123 if (ret) { 1124 qemu_mutex_unlock(&p->mutex); 1125 break; 1126 } 1127 1128 flags = p->flags; 1129 /* recv methods don't know how to handle the SYNC flag */ 1130 p->flags &= ~MULTIFD_FLAG_SYNC; 1131 trace_multifd_recv(p->id, p->packet_num, p->normal_num, flags, 1132 p->next_packet_size); 1133 p->num_packets++; 1134 p->total_normal_pages += p->normal_num; 1135 qemu_mutex_unlock(&p->mutex); 1136 1137 if (p->normal_num) { 1138 ret = multifd_recv_state->ops->recv_pages(p, &local_err); 1139 if (ret != 0) { 1140 break; 1141 } 1142 } 1143 1144 if (flags & MULTIFD_FLAG_SYNC) { 1145 qemu_sem_post(&multifd_recv_state->sem_sync); 1146 qemu_sem_wait(&p->sem_sync); 1147 } 1148 } 1149 1150 if (local_err) { 1151 multifd_recv_terminate_threads(local_err); 1152 error_free(local_err); 1153 } 1154 qemu_mutex_lock(&p->mutex); 1155 p->running = false; 1156 qemu_mutex_unlock(&p->mutex); 1157 1158 rcu_unregister_thread(); 1159 trace_multifd_recv_thread_end(p->id, p->num_packets, p->total_normal_pages); 1160 1161 return NULL; 1162 } 1163 1164 int multifd_load_setup(Error **errp) 1165 { 1166 int thread_count; 1167 uint32_t page_count = MULTIFD_PACKET_SIZE / qemu_target_page_size(); 1168 uint8_t i; 1169 1170 /* 1171 * Return successfully if multiFD recv state is already initialised 1172 * or multiFD is not enabled. 1173 */ 1174 if (multifd_recv_state || !migrate_multifd()) { 1175 return 0; 1176 } 1177 1178 thread_count = migrate_multifd_channels(); 1179 multifd_recv_state = g_malloc0(sizeof(*multifd_recv_state)); 1180 multifd_recv_state->params = g_new0(MultiFDRecvParams, thread_count); 1181 qatomic_set(&multifd_recv_state->count, 0); 1182 qemu_sem_init(&multifd_recv_state->sem_sync, 0); 1183 multifd_recv_state->ops = multifd_ops[migrate_multifd_compression()]; 1184 1185 for (i = 0; i < thread_count; i++) { 1186 MultiFDRecvParams *p = &multifd_recv_state->params[i]; 1187 1188 qemu_mutex_init(&p->mutex); 1189 qemu_sem_init(&p->sem_sync, 0); 1190 p->quit = false; 1191 p->id = i; 1192 p->packet_len = sizeof(MultiFDPacket_t) 1193 + sizeof(uint64_t) * page_count; 1194 p->packet = g_malloc0(p->packet_len); 1195 p->name = g_strdup_printf("multifdrecv_%d", i); 1196 p->iov = g_new0(struct iovec, page_count); 1197 p->normal = g_new0(ram_addr_t, page_count); 1198 p->page_count = page_count; 1199 p->page_size = qemu_target_page_size(); 1200 } 1201 1202 for (i = 0; i < thread_count; i++) { 1203 MultiFDRecvParams *p = &multifd_recv_state->params[i]; 1204 Error *local_err = NULL; 1205 int ret; 1206 1207 ret = multifd_recv_state->ops->recv_setup(p, &local_err); 1208 if (ret) { 1209 error_propagate(errp, local_err); 1210 return ret; 1211 } 1212 } 1213 return 0; 1214 } 1215 1216 bool multifd_recv_all_channels_created(void) 1217 { 1218 int thread_count = migrate_multifd_channels(); 1219 1220 if (!migrate_multifd()) { 1221 return true; 1222 } 1223 1224 if (!multifd_recv_state) { 1225 /* Called before any connections created */ 1226 return false; 1227 } 1228 1229 return thread_count == qatomic_read(&multifd_recv_state->count); 1230 } 1231 1232 /* 1233 * Try to receive all multifd channels to get ready for the migration. 1234 * Sets @errp when failing to receive the current channel. 1235 */ 1236 void multifd_recv_new_channel(QIOChannel *ioc, Error **errp) 1237 { 1238 MultiFDRecvParams *p; 1239 Error *local_err = NULL; 1240 int id; 1241 1242 id = multifd_recv_initial_packet(ioc, &local_err); 1243 if (id < 0) { 1244 multifd_recv_terminate_threads(local_err); 1245 error_propagate_prepend(errp, local_err, 1246 "failed to receive packet" 1247 " via multifd channel %d: ", 1248 qatomic_read(&multifd_recv_state->count)); 1249 return; 1250 } 1251 trace_multifd_recv_new_channel(id); 1252 1253 p = &multifd_recv_state->params[id]; 1254 if (p->c != NULL) { 1255 error_setg(&local_err, "multifd: received id '%d' already setup'", 1256 id); 1257 multifd_recv_terminate_threads(local_err); 1258 error_propagate(errp, local_err); 1259 return; 1260 } 1261 p->c = ioc; 1262 object_ref(OBJECT(ioc)); 1263 /* initial packet */ 1264 p->num_packets = 1; 1265 1266 p->running = true; 1267 qemu_thread_create(&p->thread, p->name, multifd_recv_thread, p, 1268 QEMU_THREAD_JOINABLE); 1269 qatomic_inc(&multifd_recv_state->count); 1270 } 1271