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 "socket.h" 23 #include "tls.h" 24 #include "qemu-file.h" 25 #include "trace.h" 26 #include "multifd.h" 27 #include "threadinfo.h" 28 #include "options.h" 29 #include "qemu/yank.h" 30 #include "io/channel-socket.h" 31 #include "yank_functions.h" 32 33 /* Multiple fd's */ 34 35 #define MULTIFD_MAGIC 0x11223344U 36 #define MULTIFD_VERSION 1 37 38 typedef struct { 39 uint32_t magic; 40 uint32_t version; 41 unsigned char uuid[16]; /* QemuUUID */ 42 uint8_t id; 43 uint8_t unused1[7]; /* Reserved for future use */ 44 uint64_t unused2[4]; /* Reserved for future use */ 45 } __attribute__((packed)) MultiFDInit_t; 46 47 /* Multifd without compression */ 48 49 /** 50 * nocomp_send_setup: setup send side 51 * 52 * For no compression this function does nothing. 53 * 54 * Returns 0 for success or -1 for error 55 * 56 * @p: Params for the channel that we are using 57 * @errp: pointer to an error 58 */ 59 static int nocomp_send_setup(MultiFDSendParams *p, Error **errp) 60 { 61 return 0; 62 } 63 64 /** 65 * nocomp_send_cleanup: cleanup send side 66 * 67 * For no compression this function does nothing. 68 * 69 * @p: Params for the channel that we are using 70 * @errp: pointer to an error 71 */ 72 static void nocomp_send_cleanup(MultiFDSendParams *p, Error **errp) 73 { 74 return; 75 } 76 77 /** 78 * nocomp_send_prepare: prepare date to be able to send 79 * 80 * For no compression we just have to calculate the size of the 81 * packet. 82 * 83 * Returns 0 for success or -1 for error 84 * 85 * @p: Params for the channel that we are using 86 * @errp: pointer to an error 87 */ 88 static int nocomp_send_prepare(MultiFDSendParams *p, Error **errp) 89 { 90 MultiFDPages_t *pages = p->pages; 91 92 for (int i = 0; i < p->normal_num; i++) { 93 p->iov[p->iovs_num].iov_base = pages->block->host + p->normal[i]; 94 p->iov[p->iovs_num].iov_len = p->page_size; 95 p->iovs_num++; 96 } 97 98 p->next_packet_size = p->normal_num * p->page_size; 99 p->flags |= MULTIFD_FLAG_NOCOMP; 100 return 0; 101 } 102 103 /** 104 * nocomp_recv_setup: setup receive side 105 * 106 * For no compression this function does nothing. 107 * 108 * Returns 0 for success or -1 for error 109 * 110 * @p: Params for the channel that we are using 111 * @errp: pointer to an error 112 */ 113 static int nocomp_recv_setup(MultiFDRecvParams *p, Error **errp) 114 { 115 return 0; 116 } 117 118 /** 119 * nocomp_recv_cleanup: setup receive side 120 * 121 * For no compression this function does nothing. 122 * 123 * @p: Params for the channel that we are using 124 */ 125 static void nocomp_recv_cleanup(MultiFDRecvParams *p) 126 { 127 } 128 129 /** 130 * nocomp_recv_pages: read the data from the channel into actual pages 131 * 132 * For no compression we just need to read things into the correct place. 133 * 134 * Returns 0 for success or -1 for error 135 * 136 * @p: Params for the channel that we are using 137 * @errp: pointer to an error 138 */ 139 static int nocomp_recv_pages(MultiFDRecvParams *p, Error **errp) 140 { 141 uint32_t flags = p->flags & MULTIFD_FLAG_COMPRESSION_MASK; 142 143 if (flags != MULTIFD_FLAG_NOCOMP) { 144 error_setg(errp, "multifd %u: flags received %x flags expected %x", 145 p->id, flags, MULTIFD_FLAG_NOCOMP); 146 return -1; 147 } 148 for (int i = 0; i < p->normal_num; i++) { 149 p->iov[i].iov_base = p->host + p->normal[i]; 150 p->iov[i].iov_len = p->page_size; 151 } 152 return qio_channel_readv_all(p->c, p->iov, p->normal_num, errp); 153 } 154 155 static MultiFDMethods multifd_nocomp_ops = { 156 .send_setup = nocomp_send_setup, 157 .send_cleanup = nocomp_send_cleanup, 158 .send_prepare = nocomp_send_prepare, 159 .recv_setup = nocomp_recv_setup, 160 .recv_cleanup = nocomp_recv_cleanup, 161 .recv_pages = nocomp_recv_pages 162 }; 163 164 static MultiFDMethods *multifd_ops[MULTIFD_COMPRESSION__MAX] = { 165 [MULTIFD_COMPRESSION_NONE] = &multifd_nocomp_ops, 166 }; 167 168 void multifd_register_ops(int method, MultiFDMethods *ops) 169 { 170 assert(0 < method && method < MULTIFD_COMPRESSION__MAX); 171 multifd_ops[method] = ops; 172 } 173 174 static int multifd_send_initial_packet(MultiFDSendParams *p, Error **errp) 175 { 176 MultiFDInit_t msg = {}; 177 int ret; 178 179 msg.magic = cpu_to_be32(MULTIFD_MAGIC); 180 msg.version = cpu_to_be32(MULTIFD_VERSION); 181 msg.id = p->id; 182 memcpy(msg.uuid, &qemu_uuid.data, sizeof(msg.uuid)); 183 184 ret = qio_channel_write_all(p->c, (char *)&msg, sizeof(msg), errp); 185 if (ret != 0) { 186 return -1; 187 } 188 return 0; 189 } 190 191 static int multifd_recv_initial_packet(QIOChannel *c, Error **errp) 192 { 193 MultiFDInit_t msg; 194 int ret; 195 196 ret = qio_channel_read_all(c, (char *)&msg, sizeof(msg), errp); 197 if (ret != 0) { 198 return -1; 199 } 200 201 msg.magic = be32_to_cpu(msg.magic); 202 msg.version = be32_to_cpu(msg.version); 203 204 if (msg.magic != MULTIFD_MAGIC) { 205 error_setg(errp, "multifd: received packet magic %x " 206 "expected %x", msg.magic, MULTIFD_MAGIC); 207 return -1; 208 } 209 210 if (msg.version != MULTIFD_VERSION) { 211 error_setg(errp, "multifd: received packet version %u " 212 "expected %u", msg.version, MULTIFD_VERSION); 213 return -1; 214 } 215 216 if (memcmp(msg.uuid, &qemu_uuid, sizeof(qemu_uuid))) { 217 char *uuid = qemu_uuid_unparse_strdup(&qemu_uuid); 218 char *msg_uuid = qemu_uuid_unparse_strdup((const QemuUUID *)msg.uuid); 219 220 error_setg(errp, "multifd: received uuid '%s' and expected " 221 "uuid '%s' for channel %hhd", msg_uuid, uuid, msg.id); 222 g_free(uuid); 223 g_free(msg_uuid); 224 return -1; 225 } 226 227 if (msg.id > migrate_multifd_channels()) { 228 error_setg(errp, "multifd: received channel version %u " 229 "expected %u", msg.version, MULTIFD_VERSION); 230 return -1; 231 } 232 233 return msg.id; 234 } 235 236 static MultiFDPages_t *multifd_pages_init(size_t size) 237 { 238 MultiFDPages_t *pages = g_new0(MultiFDPages_t, 1); 239 240 pages->allocated = size; 241 pages->offset = g_new0(ram_addr_t, size); 242 243 return pages; 244 } 245 246 static void multifd_pages_clear(MultiFDPages_t *pages) 247 { 248 pages->num = 0; 249 pages->allocated = 0; 250 pages->packet_num = 0; 251 pages->block = NULL; 252 g_free(pages->offset); 253 pages->offset = NULL; 254 g_free(pages); 255 } 256 257 static void multifd_send_fill_packet(MultiFDSendParams *p) 258 { 259 MultiFDPacket_t *packet = p->packet; 260 int i; 261 262 packet->flags = cpu_to_be32(p->flags); 263 packet->pages_alloc = cpu_to_be32(p->pages->allocated); 264 packet->normal_pages = cpu_to_be32(p->normal_num); 265 packet->next_packet_size = cpu_to_be32(p->next_packet_size); 266 packet->packet_num = cpu_to_be64(p->packet_num); 267 268 if (p->pages->block) { 269 strncpy(packet->ramblock, p->pages->block->idstr, 256); 270 } 271 272 for (i = 0; i < p->normal_num; i++) { 273 /* there are architectures where ram_addr_t is 32 bit */ 274 uint64_t temp = p->normal[i]; 275 276 packet->offset[i] = cpu_to_be64(temp); 277 } 278 } 279 280 static int multifd_recv_unfill_packet(MultiFDRecvParams *p, Error **errp) 281 { 282 MultiFDPacket_t *packet = p->packet; 283 RAMBlock *block; 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 block = qemu_ram_block_by_name(packet->ramblock); 334 if (!block) { 335 error_setg(errp, "multifd: unknown ram block %s", 336 packet->ramblock); 337 return -1; 338 } 339 340 p->host = 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 > (block->used_length - p->page_size)) { 345 error_setg(errp, "multifd: offset too long %" PRIu64 346 " (max " RAM_ADDR_FMT ")", 347 offset, 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(&ram_counters.transferred, transferred); 437 stat64_add(&ram_counters.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(&ram_counters.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_file_acct_rate_limit(f, p->packet_len); 630 qemu_mutex_unlock(&p->mutex); 631 stat64_add(&ram_counters.transferred, p->packet_len); 632 stat64_add(&ram_counters.multifd_bytes, p->packet_len); 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 = MigrationThreadAdd(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 qemu_mutex_lock(&p->mutex); 735 p->pending_job--; 736 qemu_mutex_unlock(&p->mutex); 737 738 if (flags & MULTIFD_FLAG_SYNC) { 739 qemu_sem_post(&p->sem_sync); 740 } 741 } else if (p->quit) { 742 qemu_mutex_unlock(&p->mutex); 743 break; 744 } else { 745 qemu_mutex_unlock(&p->mutex); 746 /* sometimes there are spurious wakeups */ 747 } 748 } 749 750 out: 751 if (local_err) { 752 trace_multifd_send_error(p->id); 753 multifd_send_terminate_threads(local_err); 754 error_free(local_err); 755 } 756 757 /* 758 * Error happen, I will exit, but I can't just leave, tell 759 * who pay attention to me. 760 */ 761 if (ret != 0) { 762 qemu_sem_post(&p->sem_sync); 763 qemu_sem_post(&multifd_send_state->channels_ready); 764 } 765 766 qemu_mutex_lock(&p->mutex); 767 p->running = false; 768 qemu_mutex_unlock(&p->mutex); 769 770 rcu_unregister_thread(); 771 MigrationThreadDel(thread); 772 trace_multifd_send_thread_end(p->id, p->num_packets, p->total_normal_pages); 773 774 return NULL; 775 } 776 777 static bool multifd_channel_connect(MultiFDSendParams *p, 778 QIOChannel *ioc, 779 Error *error); 780 781 static void multifd_tls_outgoing_handshake(QIOTask *task, 782 gpointer opaque) 783 { 784 MultiFDSendParams *p = opaque; 785 QIOChannel *ioc = QIO_CHANNEL(qio_task_get_source(task)); 786 Error *err = NULL; 787 788 if (qio_task_propagate_error(task, &err)) { 789 trace_multifd_tls_outgoing_handshake_error(ioc, error_get_pretty(err)); 790 } else { 791 trace_multifd_tls_outgoing_handshake_complete(ioc); 792 } 793 794 if (!multifd_channel_connect(p, ioc, err)) { 795 /* 796 * Error happen, mark multifd_send_thread status as 'quit' although it 797 * is not created, and then tell who pay attention to me. 798 */ 799 p->quit = true; 800 qemu_sem_post(&multifd_send_state->channels_ready); 801 qemu_sem_post(&p->sem_sync); 802 } 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 void 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(s, ioc, hostname, errp); 827 if (!tioc) { 828 return; 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 } 839 840 static bool multifd_channel_connect(MultiFDSendParams *p, 841 QIOChannel *ioc, 842 Error *error) 843 { 844 trace_multifd_set_outgoing_channel( 845 ioc, object_get_typename(OBJECT(ioc)), 846 migrate_get_current()->hostname, error); 847 848 if (error) { 849 return false; 850 } 851 if (migrate_channel_requires_tls_upgrade(ioc)) { 852 multifd_tls_channel_connect(p, ioc, &error); 853 if (!error) { 854 /* 855 * tls_channel_connect will call back to this 856 * function after the TLS handshake, 857 * so we mustn't call multifd_send_thread until then 858 */ 859 return true; 860 } else { 861 return false; 862 } 863 } else { 864 migration_ioc_register_yank(ioc); 865 p->registered_yank = true; 866 p->c = ioc; 867 qemu_thread_create(&p->thread, p->name, multifd_send_thread, p, 868 QEMU_THREAD_JOINABLE); 869 } 870 return true; 871 } 872 873 static void multifd_new_send_channel_cleanup(MultiFDSendParams *p, 874 QIOChannel *ioc, Error *err) 875 { 876 migrate_set_error(migrate_get_current(), err); 877 /* Error happen, we need to tell who pay attention to me */ 878 qemu_sem_post(&multifd_send_state->channels_ready); 879 qemu_sem_post(&p->sem_sync); 880 /* 881 * Although multifd_send_thread is not created, but main migration 882 * thread neet to judge whether it is running, so we need to mark 883 * its status. 884 */ 885 p->quit = true; 886 object_unref(OBJECT(ioc)); 887 error_free(err); 888 } 889 890 static void multifd_new_send_channel_async(QIOTask *task, gpointer opaque) 891 { 892 MultiFDSendParams *p = opaque; 893 QIOChannel *sioc = QIO_CHANNEL(qio_task_get_source(task)); 894 Error *local_err = NULL; 895 896 trace_multifd_new_send_channel_async(p->id); 897 if (!qio_task_propagate_error(task, &local_err)) { 898 p->c = QIO_CHANNEL(sioc); 899 qio_channel_set_delay(p->c, false); 900 p->running = true; 901 if (multifd_channel_connect(p, sioc, local_err)) { 902 return; 903 } 904 } 905 906 multifd_new_send_channel_cleanup(p, sioc, local_err); 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 socket_send_channel_create(multifd_new_send_channel_async, 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