migration.c

   1 /*
   2  * QEMU migration support
   3  *
   4  * Copyright (C) 2007 Anthony Liguori <anthony@codemonkey.ws>
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a copy
   7  * of this software and associated documentation files (the "Software"), to deal
   8  * in the Software without restriction, including without limitation the rights
   9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  10  * copies of the Software, and to permit persons to whom the Software is
  11  * furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be included in
  14  * all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  22  * THE SOFTWARE.
  23  */
  24
  25 #include "hw/hw.h"
  26 #include "sysemu.h"
  27 #include "block.h"
  28 #include "console.h"
  29 #include "qemu-timer.h"
  30 #include "migration.h"
  31 #include "qemu_socket.h"
  32 #include "qemu-kvm.h"
  33
  34 #include <sys/wait.h>
  35
  36 #define MIN_FINALIZE_SIZE       (200 << 10)
  37 #define MAX_ITERATIONS           30
  38 #define MAX_RAPID_WRITES          5
  39
  40 typedef struct MigrationState
  41 {
  42     int fd;
  43     int throttle_count;
  44     int bps;
  45     int updated_pages;
  46     int last_updated_pages;
  47     int iteration;
  48     int n_buffer; /* number of bytes in @buffer already sent */
  49     int l_buffer; /* number of bytes in @buffer to send */
  50     int throttled;
  51     int *has_error;
  52     char buffer[TARGET_PAGE_SIZE + 4 + 4];
  53     target_ulong addr;
  54     QEMUTimer *timer;
  55     void *opaque;
  56     int detach;
  57     int (*release)(void *opaque);
  58     int rapid_writes;
  59 } MigrationState;
  60
  61 static uint32_t max_throttle = (32 << 20);
  62 static MigrationState *current_migration;
  63 static int wait_for_message_timeout = 3000; /* 3 seconds */
  64 static int status; /* last migration status */
  65
  66 enum { /* migration status values */
  67     MIG_STAT_SUCCESS           = 0,
  68
  69     /* src error codes */
  70     MIG_STAT_INVALID_PARAMS    = 1,
  71     MIG_STAT_INVALID_ADDR      = 2,
  72     MIG_STAT_SOCKET_FAILED     = 3,
  73     MIG_STAT_SOCKOPT_FAILED    = 4,
  74     MIG_STAT_BIND_FAILED       = 5,
  75     MIG_STAT_LISTEN_FAILED     = 6,
  76     MIG_STAT_ACCEPT_FAILED     = 7,
  77     MIG_STAT_CONNECT_FAILED    = 8,
  78     MIG_STAT_WRITE_FAILED      = 9,
  79     MIG_STAT_READ_FAILED       = 10,
  80     MIG_STAT_CONNECTION_CLOSED = 11,
  81     MIG_STAT_SELECT_FAILED     = 12,
  82     MIG_STAT_SELECT_TIMEOUT    = 13,
  83     MIG_STAT_SELECT_FD_NOT_SET = 14,
  84
  85     MIG_STAT_SAVEVM_FAILED     = 15,
  86     MIG_STAT_NO_MEM            = 16,
  87
  88     MIG_STAT_MIGRATION_CANCEL  = 20,
  89
  90     /* kvm error codes (on src) */
  91     MIG_STAT_KVM_UPDATE_DIRTY_PAGES_LOG_FAILED  = 101,
  92     MIG_STAT_KVM_SET_DIRTY_TRACKING_FAILED      = 102,
  93     MIG_STAT_KVM_GET_PAGE_BITMAP                = 103,
  94
  95     /* dst error codes */
  96     MIG_STAT_DST_INVALID_PARAMS    = 200 + MIG_STAT_INVALID_PARAMS,
  97     MIG_STAT_DST_INVALID_ADDR      = 200 + MIG_STAT_INVALID_ADDR,
  98     MIG_STAT_DST_SOCKET_FAILED     = 200 + MIG_STAT_SOCKET_FAILED,
  99     MIG_STAT_DST_SOCKOPT_FAILED    = 200 + MIG_STAT_SOCKOPT_FAILED,
 100     MIG_STAT_DST_BIND_FAILED       = 200 + MIG_STAT_BIND_FAILED,
 101     MIG_STAT_DST_LISTEN_FAILED     = 200 + MIG_STAT_LISTEN_FAILED,
 102     MIG_STAT_DST_ACCEPT_FAILED     = 200 + MIG_STAT_ACCEPT_FAILED,
 103     MIG_STAT_DST_CONNECT_FAILED    = 200 + MIG_STAT_CONNECT_FAILED,
 104     MIG_STAT_DST_WRITE_FAILED      = 200 + MIG_STAT_WRITE_FAILED,
 105     MIG_STAT_DST_READ_FAILED       = 200 + MIG_STAT_READ_FAILED,
 106
 107     MIG_STAT_DST_CONNECTION_CLOSED = 200 + MIG_STAT_CONNECTION_CLOSED,
 108     MIG_STAT_DST_SELECT_FAILED     = 200 + MIG_STAT_SELECT_FAILED,
 109     MIG_STAT_DST_SELECT_TIMEOUT    = 200 + MIG_STAT_SELECT_TIMEOUT,
 110     MIG_STAT_DST_SELECT_FD_NOT_SET = 200 + MIG_STAT_SELECT_FD_NOT_SET,
 111
 112     MIG_STAT_DST_LOADVM_FAILED     = 200 + MIG_STAT_SAVEVM_FAILED,
 113     MIG_STAT_DST_NO_MEM            = 200 + MIG_STAT_NO_MEM,
 114
 115     MIG_STAT_DST_GET_PAGE_FAILED       = 230,
 116     MIG_STAT_DST_GET_PAGE_UNKNOWN_TYPE = 231,
 117     MIG_STAT_DST_MEM_SIZE_MISMATCH     = 232,
 118     MIG_STAT_DST_MEM_OUT_OF_RANGE      = 233,
 119 };
 120
 121 //#define MIGRATION_VERIFY
 122 #ifdef MIGRATION_VERIFY
 123 static int save_verify_memory(QEMUFile *f, void *opaque);
 124 static int load_verify_memory(QEMUFile *f, void *opaque, int version_id);
 125 #endif /* MIGRATION_VERIFY */
 126
 127 /* QEMUFile migration implementation */
 128
 129 static void migrate_put_buffer(void *opaque, const uint8_t *buf, int64_t pos, int size)
 130 {
 131     MigrationState *s = opaque;
 132     int offset = 0;
 133
 134     if (*s->has_error)
 135         return;
 136
 137     while (offset < size) {
 138         ssize_t len;
 139
 140         len = write(s->fd, buf + offset, size - offset);
 141         if (len == -1) {
 142             if (errno == EAGAIN || errno == EINTR)
 143                 continue;
 144             term_printf("migration: write failed (%s)\n", strerror(errno));
 145             *s->has_error = MIG_STAT_WRITE_FAILED;
 146             break;
 147         } else if (len == 0) {
 148             term_printf("migration: other side closed connection\n");
 149             *s->has_error = MIG_STAT_CONNECTION_CLOSED;
 150             break;
 151         }
 152
 153         offset += len;
 154     }
 155 }
 156
 157 static void migrate_close(void *opaque)
 158 {
 159     MigrationState *s = opaque;
 160
 161     if (s->release)
 162         s->release(s->opaque);
 163
 164     qemu_free(s);
 165     current_migration = NULL;
 166 }
 167
 168 /* Outgoing migration routines */
 169 static void migrate_finish(MigrationState *s)
 170 {
 171     QEMUFile *f;
 172     int ret = 0;
 173     int *has_error = s->has_error;
 174     int saved_vm_running = vm_running;
 175     int detach = s->detach;
 176
 177     fcntl(s->fd, F_SETFL, 0);
 178
 179     if (! *has_error) {
 180         vm_stop(0);
 181         f = qemu_fopen(s, migrate_put_buffer, NULL, migrate_close);
 182         do {
 183             qemu_aio_flush();
 184         } while (qemu_bh_poll());
 185         bdrv_flush_all();
 186
 187         if (kvm_enabled() && !*s->has_error && kvm_update_dirty_pages_log())
 188             *s->has_error = MIG_STAT_KVM_UPDATE_DIRTY_PAGES_LOG_FAILED;
 189
 190         qemu_put_be32(f, 1);
 191         ret = qemu_live_savevm_state(f);
 192 #ifdef MIGRATION_VERIFY
 193         save_verify_memory(f, NULL);
 194 #endif /* MIGRATION_VERIFY */
 195         qemu_fclose(f);
 196     } else {
 197             migrate_close(s);
 198     }
 199     status = *has_error;
 200     if (ret && !status)
 201         status = MIG_STAT_SAVEVM_FAILED;
 202     if (status) {
 203         term_printf("Migration failed! ret=%d error=%d\n", ret, *has_error);
 204         if (saved_vm_running)
 205             vm_start();
 206     }
 207     if (!detach)
 208         monitor_resume();
 209     qemu_free(has_error);
 210     cpu_physical_memory_set_dirty_tracking(0);
 211 }
 212
 213 static int migrate_write_buffer(MigrationState *s)
 214 {
 215     if (*s->has_error)
 216         return 0;
 217
 218     if (s->n_buffer < s->l_buffer) {
 219         ssize_t len;
 220     again:
 221         len = write(s->fd, s->buffer + s->n_buffer, s->l_buffer - s->n_buffer);
 222         if (len == -1) {
 223             if (errno == EINTR)
 224                 goto again;
 225             if (errno == EAGAIN)
 226                 return 1;
 227             *s->has_error = MIG_STAT_WRITE_FAILED;
 228             return 0;
 229         }
 230         if (len == 0) {
 231             *s->has_error = MIG_STAT_CONNECTION_CLOSED;
 232             return 0;
 233         }
 234
 235         s->throttle_count += len;
 236         s->n_buffer += len;
 237         if (s->n_buffer < s->l_buffer)
 238             goto again;
 239     }
 240
 241     if (s->throttle_count > max_throttle) {
 242         s->throttled = 1;
 243         qemu_set_fd_handler2(s->fd, NULL, NULL, NULL, NULL);
 244         return 1;
 245     }
 246
 247     return 0;
 248 }
 249
 250 static int migrate_check_convergence(MigrationState *s)
 251 {
 252     target_ulong addr;
 253     int dirty_count = 0;
 254
 255     if ((s->iteration >= MAX_ITERATIONS) ||
 256         (s->rapid_writes >= MAX_RAPID_WRITES) ) {
 257         return 1;
 258     }
 259
 260     for (addr = 0; addr < phys_ram_size; addr += TARGET_PAGE_SIZE) {
 261         if (kvm_enabled() && (addr>=0xa0000) && (addr<0xc0000)) /* do not access video-addresses */
 262             continue;
 263         if (cpu_physical_memory_get_dirty(addr, MIGRATION_DIRTY_FLAG))
 264             dirty_count++;
 265     }
 266
 267     return ((dirty_count * TARGET_PAGE_SIZE) < MIN_FINALIZE_SIZE);
 268 }
 269
 270 static int ram_page_is_homogeneous(uint32_t addr)
 271 {
 272     int i, n;
 273     uint32_t *p, v;
 274
 275     n = TARGET_PAGE_SIZE / sizeof(v);
 276     p = (uint32 *)(phys_ram_base + addr);
 277
 278     v = p[0];
 279     for (i=1; i<n; i++)
 280         if (p[i] != v)
 281             return 0;
 282     return 1;
 283 }
 284
 285 static void migrate_prepare_page(MigrationState *s)
 286 {
 287     uint32_t value;
 288     char type;
 289     const char *buff;
 290     int bufflen;
 291
 292     value = cpu_to_be32(s->addr);
 293     memcpy(s->buffer, &value, 4);
 294
 295     if (ram_page_is_homogeneous(s->addr)) {
 296         type = 1; /* keeping ram_get_page() values */
 297         bufflen = 4;
 298     }
 299     else {
 300         type = 0;
 301         bufflen = TARGET_PAGE_SIZE;
 302     }
 303
 304     buff = phys_ram_base + s->addr;
 305     s->buffer[4] = type;
 306     memcpy(s->buffer + 4 + 1, phys_ram_base + s->addr, bufflen);
 307     s->n_buffer = 0;
 308     s->l_buffer = 4 + 1 + bufflen;
 309 }
 310
 311 static void migrate_write(void *opaque)
 312 {
 313     MigrationState *s = opaque;
 314
 315     if (migrate_write_buffer(s))
 316         return;
 317
 318     if (kvm_enabled() && !*s->has_error && kvm_update_dirty_pages_log())
 319         *s->has_error = MIG_STAT_KVM_UPDATE_DIRTY_PAGES_LOG_FAILED;
 320
 321     if (migrate_check_convergence(s) || *s->has_error) {
 322         qemu_del_timer(s->timer);
 323         qemu_free_timer(s->timer);
 324         qemu_set_fd_handler2(s->fd, NULL, NULL, NULL, NULL);
 325         migrate_finish(s);
 326         return;
 327     }
 328
 329     while (s->addr < phys_ram_size) {
 330         if (kvm_enabled() && (s->addr>=0xa0000) && (s->addr<0xc0000)) /* do not access video-addresses */
 331             s->addr = 0xc0000;
 332
 333         if (cpu_physical_memory_get_dirty(s->addr, MIGRATION_DIRTY_FLAG)) {
 334             migrate_prepare_page(s);
 335             cpu_physical_memory_reset_dirty(s->addr, s->addr + TARGET_PAGE_SIZE, MIGRATION_DIRTY_FLAG);
 336
 337             s->addr += TARGET_PAGE_SIZE;
 338
 339             s->updated_pages++;
 340
 341             if (migrate_write_buffer(s))
 342                 return;
 343         } else
 344             s->addr += TARGET_PAGE_SIZE;
 345     }
 346
 347     if ((s->iteration) && (s->last_updated_pages <= s->updated_pages)) {
 348         s->rapid_writes++; /* "dirt-speed" is faster than transfer speed */
 349         if (max_throttle < (1 << 30))
 350             max_throttle *= 2; /* try harder */
 351     }
 352     s->last_updated_pages = s->updated_pages;
 353     s->updated_pages = 0;
 354     s->addr = 0;
 355     s->iteration++;
 356 }
 357
 358 static void migrate_reset_throttle(void *opaque)
 359 {
 360     MigrationState *s = opaque;
 361
 362     s->bps = s->throttle_count;
 363
 364     if (s->throttled) {
 365         s->throttled = 0;
 366         qemu_set_fd_handler2(s->fd, NULL, NULL, migrate_write, s);
 367     }
 368     s->throttle_count = 0;
 369     qemu_mod_timer(s->timer, qemu_get_clock(rt_clock) + 1000);
 370 }
 371
 372 static int write_whole_buffer(int fd, const void *buff, size_t size)
 373 {
 374     size_t offset = 0, len;
 375
 376     while (offset < size) {
 377         len = write(fd, buff + offset, size - offset);
 378         if (len == -1 && errno == EINTR)
 379             continue;
 380         if (len < 1)
 381             return -EIO;
 382
 383         offset += len;
 384     }
 385     return !(offset == size); /* returns 0 on success */
 386 }
 387
 388 static int bit_is_set(int bit, unsigned char *map)
 389 {
 390     return map[bit/8] & (1 << (bit%8));
 391 }
 392
 393 static int start_migration(MigrationState *s)
 394 {
 395     uint32_t value = cpu_to_be32(phys_ram_size);
 396     target_phys_addr_t addr;
 397     int r;
 398     unsigned char running = vm_running?2:1; /* 1 + vm_running */
 399     int n = 0;
 400     unsigned char *phys_ram_page_exist_bitmap = NULL;
 401
 402     if (kvm_enabled()) {
 403         n = BITMAP_SIZE(phys_ram_size);
 404         phys_ram_page_exist_bitmap = qemu_malloc(n);
 405         if (!phys_ram_page_exist_bitmap) {
 406             perror("failed to allocate page bitmap");
 407             r = MIG_STAT_NO_MEM;
 408             goto out;
 409         }
 410         if (kvm_get_phys_ram_page_bitmap(phys_ram_page_exist_bitmap)) {
 411             r = MIG_STAT_KVM_GET_PAGE_BITMAP;
 412             perror("kvm_get_mem_map failed");
 413             goto out;
 414         }
 415     }
 416
 417     r = MIG_STAT_WRITE_FAILED;
 418     if (write_whole_buffer(s->fd, &running, sizeof(running))) {
 419         perror("vm_running write failed");
 420         goto out;
 421     }
 422     if (write_whole_buffer(s->fd, &value, sizeof(value))) {
 423         perror("phys_ram_size write failed");
 424         goto out;
 425     }
 426
 427     if (kvm_enabled()) {
 428         value = cpu_to_be32(n);
 429         if (write_whole_buffer(s->fd, &value, sizeof(value))) {
 430             perror("phys_ram_size_bitmap size write failed");
 431             goto out;
 432         }
 433         if (write_whole_buffer(s->fd, phys_ram_page_exist_bitmap, n)) {
 434             perror("phys_ram_page_exist_bitmap write failed");
 435             goto out;
 436         }
 437     }
 438
 439     fcntl(s->fd, F_SETFL, O_NONBLOCK);
 440
 441     for (addr = 0; addr < phys_ram_size; addr += TARGET_PAGE_SIZE) {
 442         if (kvm_enabled() && !bit_is_set(addr>>TARGET_PAGE_BITS, phys_ram_page_exist_bitmap)) {
 443             cpu_physical_memory_reset_dirty(addr,
 444                                             addr + TARGET_PAGE_SIZE,
 445                                             MIGRATION_DIRTY_FLAG);
 446             continue;
 447         }
 448         if (!cpu_physical_memory_get_dirty(addr, MIGRATION_DIRTY_FLAG))
 449             cpu_physical_memory_set_dirty(addr);
 450     }
 451
 452     if (cpu_physical_memory_set_dirty_tracking(1)) {
 453         *s->has_error = MIG_STAT_KVM_SET_DIRTY_TRACKING_FAILED;
 454         r = MIG_STAT_KVM_SET_DIRTY_TRACKING_FAILED;
 455         goto out;
 456     }
 457
 458     s->addr = 0;
 459     s->iteration = 0;
 460     s->updated_pages = 0;
 461     s->last_updated_pages = 0;
 462     s->n_buffer = s->l_buffer = 0;
 463     s->rapid_writes = 0;
 464     s->timer = qemu_new_timer(rt_clock, migrate_reset_throttle, s);
 465
 466     qemu_mod_timer(s->timer, qemu_get_clock(rt_clock));
 467     qemu_set_fd_handler2(s->fd, NULL, NULL, migrate_write, s);
 468
 469     r = 0;
 470
 471  out:
 472     if (kvm_enabled() && phys_ram_page_exist_bitmap)
 473         qemu_free(phys_ram_page_exist_bitmap);
 474     return r;
 475 }
 476
 477 static MigrationState *migration_init_fd(int detach, int fd)
 478 {
 479     MigrationState *s;
 480
 481     s = qemu_mallocz(sizeof(MigrationState));
 482     if (s == NULL) {
 483         term_printf("Allocation error\n");
 484         return NULL;
 485     }
 486
 487     s->fd = fd;
 488     s->has_error = qemu_mallocz(sizeof(int));
 489     if (s->has_error == NULL) {
 490         term_printf("malloc failed (for has_error)\n");
 491         return NULL;
 492     }
 493     s->detach = detach;
 494
 495     current_migration = s;
 496
 497     if (start_migration(s)) {
 498         term_printf("Could not start migration\n");
 499         migrate_finish(s);
 500         return NULL;
 501     }
 502
 503     if (!detach)
 504         monitor_suspend();
 505
 506     return s;
 507 }
 508
 509 typedef struct MigrationCmdState
 510 {
 511     int fd;
 512     pid_t pid;
 513 } MigrationCmdState;
 514
 515 static int cmd_release(void *opaque)
 516 {
 517     MigrationCmdState *c = opaque;
 518     int status, ret;
 519
 520     close(c->fd);
 521
 522 again:
 523     ret = waitpid(c->pid, &status, 0);
 524     if (ret == -1 && errno == EINTR)
 525         goto again;
 526
 527     if (ret == -1) {
 528         term_printf("migration: waitpid failed (%s)\n", strerror(errno));
 529         return -1;
 530     }
 531     /* FIXME: check and uncomment
 532      * if (WIFEXITED(status))
 533      *     status = WEXITSTATUS(status);
 534      */
 535     return status;
 536 }
 537
 538 static MigrationState *migration_init_cmd(int detach, const char *command, char **argv)
 539 {
 540     int fds[2];
 541     pid_t pid;
 542     int i;
 543     MigrationState *s;
 544
 545     if (pipe(fds) == -1) {
 546         term_printf("pipe() (%s)\n", strerror(errno));
 547         return NULL;
 548     }
 549
 550     pid = fork();
 551     if (pid == -1) {
 552         close(fds[0]);
 553         close(fds[1]);
 554         term_printf("fork error (%s)\n", strerror(errno));
 555         return NULL;
 556     }
 557     if (pid == 0) {
 558         close(fds[1]);
 559         dup2(fds[0], STDIN_FILENO);
 560         execvp(command, argv);
 561         exit(1);
 562     } else
 563         close(fds[0]);
 564
 565     for (i = 0; argv[i]; i++)
 566         qemu_free(argv[i]);
 567     qemu_free(argv);
 568
 569     s = migration_init_fd(detach, fds[1]);
 570     if (s) {
 571         MigrationCmdState *c = qemu_mallocz(sizeof(*c));
 572         c->pid = pid;
 573         c->fd = fds[1];
 574         s->release = cmd_release;
 575         s->opaque = c;
 576     }
 577
 578     return s;
 579 }
 580
 581 static MigrationState *migration_init_exec(int detach, const char *command)
 582 {
 583     char **argv = NULL;
 584
 585     argv = qemu_mallocz(sizeof(char *) * 4);
 586     argv[0] = strdup("sh");
 587     argv[1] = strdup("-c");
 588     argv[2] = strdup(command);
 589     argv[3] = NULL;
 590
 591     return migration_init_cmd(detach, "/bin/sh", argv);
 592 }
 593
 594
 595 static int file_release(void *opaque)
 596 {
 597     int fd = (int)(long)opaque;
 598     close(fd);
 599     return 0;
 600 }
 601
 602 static MigrationState *migration_init_file(int detach, const char *filename)
 603 {
 604     int fd;
 605     MigrationState *s;
 606
 607     fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0600);
 608     if (fd == -1) {
 609         term_printf("open file %s failed (%s)\n", filename, strerror(errno));
 610         return NULL;
 611     }
 612
 613     s = migration_init_fd(detach, fd);
 614     if (s) {
 615         s->release = file_release;
 616         s->opaque = (void*)(long)fd;
 617         max_throttle = 1U << 31;
 618     }
 619
 620     return s;
 621 }
 622
 623 static MigrationState *migration_init_ssh(int detach, const char *host)
 624 {
 625     int qemu_argc, daemonize = 0, argc, i;
 626     char **qemu_argv, **argv;
 627     const char *incoming = NULL;
 628
 629     qemu_get_launch_info(&qemu_argc, &qemu_argv, &daemonize, &incoming);
 630
 631     argc = 3 + qemu_argc;
 632     if (!daemonize)
 633         argc++;
 634     if (!incoming)
 635         argc+=2;
 636
 637     argv = qemu_mallocz(sizeof(char *) * (argc + 1));
 638     argv[0] = strdup("ssh");
 639     argv[1] = strdup("-XC");
 640     argv[2] = strdup(host);
 641
 642     for (i = 0; i < qemu_argc; i++)
 643         argv[3 + i] = strdup(qemu_argv[i]);
 644
 645     if (!daemonize)
 646         argv[3 + i++] = strdup("-daemonize");
 647     if (!incoming) {
 648         argv[3 + i++] = strdup("-incoming");
 649         argv[3 + i++] = strdup("stdio");
 650     }
 651
 652     argv[3 + i] = NULL;
 653
 654     return migration_init_cmd(detach, "ssh", argv);
 655 }
 656
 657 /* (busy) wait timeout (miliseconds) for a message to arrive on fd. */
 658 /* returns 0 on success error_code otherwise (18 for timeout) */
 659 static int wait_for_message(const char *msg, int fd, int timeout)
 660 {
 661     fd_set rfds;
 662     struct timeval tv;
 663     int64_t now, expiration, delta; /* milliseconds */
 664     int n = 0;
 665
 666     now = qemu_get_clock(rt_clock);
 667     expiration = now + timeout;
 668     do {
 669         FD_ZERO(&rfds);
 670         FD_SET(fd, &rfds);
 671         tv.tv_sec = tv.tv_usec = 0;
 672         now = qemu_get_clock(rt_clock);
 673         delta = expiration - now;
 674         if (delta > 0)
 675             tv.tv_usec = delta * 1000;
 676         n = select(fd + 1, &rfds, NULL, NULL, &tv);
 677     } while ( (n == -1) && (errno == EINTR) );
 678
 679     switch (n) {
 680     case -1: /* error */
 681         fprintf(stderr, "%s FAILED: ", msg);
 682         perror("");
 683         return MIG_STAT_SELECT_FAILED;
 684     case 0: /* timeout */
 685         fprintf(stderr, "%s: timeout reached\n", msg);
 686         return MIG_STAT_SELECT_TIMEOUT;
 687     case 1:
 688         break;
 689     default:
 690         fprintf(stderr, "wait_for_message: %s: select returned  %d\n", msg, n);
 691     }
 692     if (!FD_ISSET(fd, &rfds)) {
 693         fprintf(stderr, "wait_for_message: %s: s->fd not set\n", msg);
 694         return MIG_STAT_SELECT_FD_NOT_SET;
 695     }
 696
 697     return 0;
 698 }
 699
 700 static int tcp_release(void *opaque)
 701 {
 702     MigrationState *s = opaque;
 703     uint8_t status = 0;
 704     ssize_t len = 0;
 705     int n;
 706
 707     if (*s->has_error)
 708         goto out;
 709
 710     n = wait_for_message("WAIT FOR ACK", s->fd, wait_for_message_timeout);
 711     if (n) {
 712         *s->has_error = n;
 713         goto out;
 714     }
 715
 716 wait_for_ack:
 717     len = read(s->fd, &status, 1);
 718     if (len == -1 && errno == EINTR)
 719         goto wait_for_ack;
 720     if (len != 1 || status != 0) {
 721         *s->has_error = MIG_STAT_READ_FAILED;
 722         fprintf(stderr, "migration: wait_for_ack: read error l=%zu s=%d(%s)\n",
 723                 len, status, strerror(errno));
 724         goto out;
 725     }
 726
 727 send_go:
 728     len = write(s->fd, &status, 1);
 729     if (len == -1 && errno == EINTR)
 730         goto send_go;
 731     if (len != 1) {
 732         fprintf(stderr, "migration: send_go: write error l=%zu (%s)\n",
 733                 len, strerror(errno));
 734         *s->has_error = MIG_STAT_WRITE_FAILED;
 735     }
 736
 737 out:
 738     close(s->fd);
 739
 740     return (len != 1 || status != 0);
 741 }
 742
 743 static MigrationState *migration_init_tcp(int detach, const char *host)
 744 {
 745     int fd;
 746     struct sockaddr_in addr;
 747     MigrationState *s;
 748
 749     fd = socket(PF_INET, SOCK_STREAM, 0);
 750     if (fd == -1) {
 751         term_printf("socket() failed %s\n", strerror(errno));
 752         status = MIG_STAT_SOCKET_FAILED;
 753         return NULL;
 754     }
 755
 756     addr.sin_family = AF_INET;
 757     if (parse_host_port(&addr, host) == -1) {
 758         term_printf("parse_host_port() FAILED for %s\n", host);
 759         close(fd);
 760         status = MIG_STAT_INVALID_ADDR;
 761         return NULL;
 762     }
 763
 764 again:
 765     if (connect(fd, (struct sockaddr *)&addr, sizeof(addr)) == -1) {
 766         if (errno == EINTR)
 767             goto again;
 768         term_printf("connect() failed %s\n", strerror(errno));
 769         close(fd);
 770         status = MIG_STAT_CONNECT_FAILED;
 771         return NULL;
 772     }
 773
 774     s = migration_init_fd(detach, fd);
 775     if (s) {
 776         s->opaque = s;
 777         s->release = tcp_release;
 778     }
 779     return s;
 780 }
 781
 782 /* Incoming migration */
 783
 784 static void migrate_incoming_homogeneous_page(uint32_t addr, uint32_t v)
 785 {
 786     int i, n;
 787     uint32_t *p;
 788
 789     n = TARGET_PAGE_SIZE / sizeof(v);
 790     p = (uint32 *)(phys_ram_base + addr);
 791
 792     for (i=0; i<n; i++)
 793         p[i] = v;
 794 }
 795
 796 static int migrate_incoming_page(QEMUFile *f, uint32_t addr)
 797 {
 798     int l, v, ret = 0;
 799
 800     switch (qemu_get_byte(f)) {
 801     case 0: /* the whole page */
 802         l = qemu_get_buffer(f, phys_ram_base + addr, TARGET_PAGE_SIZE);
 803         if (l != TARGET_PAGE_SIZE)
 804             ret = MIG_STAT_DST_GET_PAGE_FAILED;
 805         break;
 806     case 1: /* homogeneous page -- a single byte */
 807         l = qemu_get_buffer(f, (void*)&v, 4);
 808         if (l != 4)
 809             ret = MIG_STAT_DST_GET_PAGE_FAILED;
 810         migrate_incoming_homogeneous_page(addr, v);
 811         break;
 812     default:
 813         ret = MIG_STAT_DST_GET_PAGE_UNKNOWN_TYPE;
 814     }
 815
 816     return ret;
 817 }
 818
 819 static int migrate_incoming_fd(int fd)
 820 {
 821     int ret = 0;
 822     QEMUFile *f = qemu_fopen_fd(fd);
 823     uint32_t addr, size;
 824     extern void qemu_announce_self(void);
 825     unsigned char running;
 826
 827     running = qemu_get_byte(f);
 828     if ((running != 1) && (running != 2)) {
 829         fprintf(stderr, "migration: illegal running value %u, not (1 or 2)\n",
 830                 running);
 831         return MIG_STAT_DST_MEM_SIZE_MISMATCH;
 832     }
 833     autostart = running - 1;
 834
 835     size = qemu_get_be32(f);
 836     if (size != phys_ram_size) {
 837         fprintf(stderr, "migration: memory size mismatch: recv %u mine %llu\n",
 838                 size, (unsigned long long)phys_ram_size);
 839         return MIG_STAT_DST_MEM_SIZE_MISMATCH;
 840     }
 841
 842     if (kvm_enabled()) {
 843         int n, m;
 844         unsigned char *phys_ram_page_exist_bitmap = NULL;
 845
 846         /* allocate memory bitmap */
 847         n = BITMAP_SIZE(phys_ram_size);
 848         m = qemu_get_be32(f);
 849         if (m > n) // allocate enough space
 850             n = m;
 851         phys_ram_page_exist_bitmap = qemu_malloc(n);
 852         if (!phys_ram_page_exist_bitmap) {
 853             perror("failed to allocate page bitmap");
 854             return MIG_STAT_NO_MEM;
 855         }
 856
 857         /* receive memory bitmap */
 858         qemu_get_buffer(f, phys_ram_page_exist_bitmap, m);
 859
 860         /* FIXME: free dellocated-at-src guest memory pages */
 861
 862         qemu_free(phys_ram_page_exist_bitmap);
 863     }
 864
 865     do {
 866         addr = qemu_get_be32(f);
 867         if (addr == 1)
 868             break;
 869         if (addr >= phys_ram_size)
 870             return MIG_STAT_DST_MEM_OUT_OF_RANGE;
 871         ret = migrate_incoming_page(f, addr);
 872         if (ret)
 873             return ret;
 874     } while (1);
 875
 876
 877     qemu_aio_flush();
 878     vm_stop(0);
 879     if (qemu_live_loadvm_state(f))
 880         ret = MIG_STAT_DST_LOADVM_FAILED;
 881 #ifdef MIGRATION_VERIFY
 882     if (ret==0) ret=load_verify_memory(f, NULL, 1);
 883 #endif /* MIGRATION_VERIFY */
 884     qemu_fclose(f);
 885
 886     return ret;
 887 }
 888
 889 static int migrate_incoming_tcp(const char *host)
 890 {
 891     struct sockaddr_in addr;
 892     socklen_t addrlen = sizeof(addr);
 893     int fd, sfd;
 894     ssize_t len;
 895     uint8_t status = 0;
 896     int reuse = 1;
 897     int rc;
 898
 899     addr.sin_family = AF_INET;
 900     if (parse_host_port(&addr, host) == -1) {
 901         fprintf(stderr, "parse_host_port() failed for %s\n", host);
 902         rc = MIG_STAT_DST_INVALID_ADDR;
 903         goto error;
 904     }
 905
 906     fd = socket(PF_INET, SOCK_STREAM, 0);
 907     if (fd == -1) {
 908         perror("socket failed");
 909         rc = MIG_STAT_DST_SOCKET_FAILED;
 910         goto error;
 911     }
 912
 913     if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &reuse, sizeof(reuse)) == -1) {
 914         perror("setsockopt() failed");
 915         rc = MIG_STAT_DST_SOCKOPT_FAILED;
 916         goto error_socket;
 917     }
 918
 919     if (bind(fd, (struct sockaddr *)&addr, sizeof(addr)) == -1) {
 920         perror("bind() failed");
 921         rc = MIG_STAT_DST_BIND_FAILED;
 922         goto error_socket;
 923     }
 924
 925     if (listen(fd, 1) == -1) {
 926         perror("listen() failed");
 927         rc = MIG_STAT_DST_LISTEN_FAILED;
 928         goto error_socket;
 929     }
 930
 931 again:
 932     sfd = accept(fd, (struct sockaddr *)&addr, &addrlen);
 933     if (sfd == -1) {
 934         if (errno == EINTR)
 935             goto again;
 936         perror("accept() failed");
 937         rc = MIG_STAT_DST_ACCEPT_FAILED;
 938         goto error_socket;
 939     }
 940
 941     rc = migrate_incoming_fd(sfd);
 942     if (rc != 0) {
 943         fprintf(stderr, "migrate_incoming_fd failed (rc=%d)\n", rc);
 944         goto error_accept;
 945     }
 946
 947 send_ack:
 948     len = write(sfd, &status, 1);
 949     if (len == -1 && errno == EAGAIN)
 950         goto send_ack;
 951     if (len != 1) {
 952         fprintf(stderr, "migration: send_ack: write error len=%zu (%s)\n",
 953                 len, strerror(errno));
 954         rc = MIG_STAT_DST_WRITE_FAILED;
 955         goto error_accept;
 956     }
 957
 958     rc = wait_for_message("WAIT FOR GO", sfd, wait_for_message_timeout);
 959     if (rc) {
 960         rc += 200;
 961         goto error_accept;
 962     }
 963
 964 wait_for_go:
 965     len = read(sfd, &status, 1);
 966     if (len == -1 && errno == EAGAIN)
 967         goto wait_for_go;
 968     if (len != 1) {
 969         rc = MIG_STAT_DST_READ_FAILED;
 970         fprintf(stderr, "migration: wait_for_go: read error len=%zu (%s)\n",
 971                 len, strerror(errno));
 972     }
 973
 974 error_accept:
 975     close(sfd);
 976 error_socket:
 977     close(fd);
 978 error:
 979     return rc;
 980 }
 981
 982 int migrate_incoming(const char *device)
 983 {
 984     const char *ptr;
 985     int ret = 0;
 986
 987     if (strcmp(device, "stdio") == 0)
 988         ret = migrate_incoming_fd(STDIN_FILENO);
 989     else if (strstart(device, "file://", &ptr)) {
 990         int fd = open(ptr, O_RDONLY);
 991         if (fd < 0) {
 992             ret = MIG_STAT_DST_INVALID_PARAMS;
 993         } else {
 994             ret = migrate_incoming_fd(fd);
 995             close(fd);
 996         }
 997     } else if (strstart(device, "tcp://", &ptr)) {
 998         char *host, *end;
 999         host = strdup(ptr);
1000         end = strchr(host, '/');
1001         if (end) *end = 0;
1002         ret = migrate_incoming_tcp(host);
1003         qemu_free(host);
1004     } else {
1005         errno = EINVAL;
1006         ret = MIG_STAT_DST_INVALID_PARAMS;
1007     }
1008
1009     return ret;
1010 }
1011
1012 /* Migration monitor command */
1013
1014 /* TODO:
1015    1) audit all error paths
1016 */
1017
1018 void do_migrate(int detach, const char *uri)
1019 {
1020     const char *ptr;
1021     MigrationState *s = current_migration;
1022
1023     if (s) {
1024         term_printf("Migration already active\n");
1025         return;
1026     }
1027
1028     status = MIG_STAT_INVALID_PARAMS;
1029     if (strstart(uri, "exec:", &ptr)) {
1030         char *command = urldecode(ptr);
1031         migration_init_exec(detach, command);
1032         free(command);
1033     } else if (strstart(uri, "ssh://", &ptr)) {
1034         char *host, *end;
1035
1036         host = strdup(ptr);
1037         end = strchr(host, '/');
1038         if (end) *end = 0;
1039         migration_init_ssh(detach, host);
1040         qemu_free(host);
1041     } else if (strstart(uri, "tcp://", &ptr)) {
1042         char *host, *end;
1043
1044         host = strdup(ptr);
1045         end = strchr(host, '/');
1046         if (end) *end = 0;
1047
1048         if (migration_init_tcp(detach, host) == NULL)
1049             term_printf("migration failed (migration_init_tcp for %s failed)\n", host);
1050         free(host);
1051     } else if (strstart(uri, "file://", &ptr)) {
1052         if (migration_init_file(detach, ptr) == NULL)
1053             term_printf("migration failed (migration_init_file for %s failed)\n", ptr);
1054     } else {
1055         term_printf("Unknown migration protocol '%s'\n", uri);
1056         return;
1057     }
1058 }
1059
1060 void do_migrate_set_speed(const char *value)
1061 {
1062     double d;
1063     char *ptr;
1064
1065     d = strtod(value, &ptr);
1066     switch (*ptr) {
1067     case 'G': case 'g':
1068         d *= 1024;
1069     case 'M': case 'm':
1070         d *= 1024;
1071     case 'K': case 'k':
1072         d *= 1024;
1073     default:
1074         break;
1075     }
1076
1077     max_throttle = (uint32_t)d;
1078 }
1079
1080 void do_info_migration(void)
1081 {
1082     MigrationState *s = current_migration;
1083
1084     if (s) {
1085         term_printf("Migration active\n");
1086         if (s->bps < (1 << 20))
1087             term_printf("Transfer rate %3.1f kb/s\n",
1088                         (double)s->bps / 1024);
1089         else
1090             term_printf("Transfer rate %3.1f mb/s\n",
1091                         (double)s->bps / (1024 * 1024));
1092         term_printf("Iteration %d\n", s->iteration);
1093         term_printf("Transferred %d/%llu pages\n", s->updated_pages,
1094                     (unsigned long long)phys_ram_size >> TARGET_PAGE_BITS);
1095         if (s->iteration)
1096             term_printf("Last iteration found %d dirty pages\n", s->last_updated_pages);
1097     } else {
1098         term_printf("Migration inactive\n");
1099         term_printf("last migration status is %d\n", status);
1100     }
1101     term_printf("Maximum migration speed is ");
1102     if (max_throttle < (1 << 20))
1103         term_printf("%3.1f kb/s\n", (double)max_throttle / 1024);
1104     else
1105         term_printf("%3.1f mb/s\n", (double)max_throttle / (1024 * 1024));
1106 }
1107
1108 void do_migrate_cancel(void)
1109 {
1110     MigrationState *s = current_migration;
1111
1112     if (s)
1113         *s->has_error = MIG_STAT_MIGRATION_CANCEL;
1114 }
1115
1116
1117
1118 #ifdef MIGRATION_VERIFY
1119 unsigned int calc_page_checksum(target_ulong addr)
1120 {
1121     unsigned int sum=0;
1122     unsigned int *p = (unsigned int *)(phys_ram_base + addr);
1123     unsigned int *q = p + (TARGET_PAGE_SIZE / sizeof(unsigned int));
1124
1125     for ( /*initialized already */ ; p<q ; p++)
1126         sum += *p;
1127     return sum;
1128 }
1129
1130
1131 static int save_verify_memory(QEMUFile *f, void *opaque)
1132 {
1133     unsigned int addr;
1134     unsigned int sum;
1135
1136     for (addr = 0; addr < phys_ram_size; addr += TARGET_PAGE_SIZE) {
1137         if (kvm_enabled() && (addr>=0xa0000) && (addr<0xc0000)) /* do not access video-addresses */
1138             continue;
1139         sum = calc_page_checksum(addr);
1140         qemu_put_be32(f, addr);
1141         qemu_put_be32(f, sum);
1142     }
1143     return 0;
1144 }
1145
1146 static int load_verify_memory(QEMUFile *f, void *opaque, int version_id)
1147 {
1148     unsigned int addr, raddr;
1149     unsigned int sum, rsum;
1150     int num_errors = 0;
1151
1152     for (addr = 0; addr < phys_ram_size; addr += TARGET_PAGE_SIZE) {
1153         if (kvm_enabled() && (addr>=0xa0000) && (addr<0xc0000)) /* do not access video-addresses */
1154             continue;
1155         sum = calc_page_checksum(addr);
1156         raddr = qemu_get_be32(f);
1157         rsum  = qemu_get_be32(f);
1158         if ((raddr != addr) || (rsum != sum)) {
1159             term_printf("checksum mismatch: src:0x%x 0x%x , dst:0x%x 0x%x\n",
1160                     raddr, rsum, addr, sum);
1161             num_errors++;
1162         }
1163     }
1164     printf("memory_verify: num_errors=%d\n", num_errors);
1165     term_printf("memory_verify: num_errors=%d\n", num_errors);
1166     return 0/* num_errors */;
1167 }
1168 #endif /* MIGRATION_VERIFY */