net/colo-compare.c

   1 /*
   2  * COarse-grain LOck-stepping Virtual Machines for Non-stop Service (COLO)
   3  * (a.k.a. Fault Tolerance or Continuous Replication)
   4  *
   5  * Copyright (c) 2016 HUAWEI TECHNOLOGIES CO., LTD.
   6  * Copyright (c) 2016 FUJITSU LIMITED
   7  * Copyright (c) 2016 Intel Corporation
   8  *
   9  * Author: Zhang Chen <zhangchen.fnst@cn.fujitsu.com>
  10  *
  11  * This work is licensed under the terms of the GNU GPL, version 2 or
  12  * later.  See the COPYING file in the top-level directory.
  13  */
  14
  15 #include "qemu/osdep.h"
  16 #include "qemu/error-report.h"
  17 #include "trace.h"
  18 #include "qemu-common.h"
  19 #include "qapi/qmp/qerror.h"
  20 #include "qapi/error.h"
  21 #include "net/net.h"
  22 #include "net/eth.h"
  23 #include "qom/object_interfaces.h"
  24 #include "qemu/iov.h"
  25 #include "qom/object.h"
  26 #include "qemu/typedefs.h"
  27 #include "net/queue.h"
  28 #include "sysemu/char.h"
  29 #include "qemu/sockets.h"
  30 #include "qapi-visit.h"
  31 #include "net/colo.h"
  32
  33 #define TYPE_COLO_COMPARE "colo-compare"
  34 #define COLO_COMPARE(obj) \
  35     OBJECT_CHECK(CompareState, (obj), TYPE_COLO_COMPARE)
  36
  37 #define COMPARE_READ_LEN_MAX NET_BUFSIZE
  38 #define MAX_QUEUE_SIZE 1024
  39
  40 /* TODO: Should be configurable */
  41 #define REGULAR_PACKET_CHECK_MS 3000
  42
  43 /*
  44   + CompareState ++
  45   |               |
  46   +---------------+   +---------------+         +---------------+
  47   |conn list      +--->conn           +--------->conn           |
  48   +---------------+   +---------------+         +---------------+
  49   |               |     |           |             |          |
  50   +---------------+ +---v----+  +---v----+    +---v----+ +---v----+
  51                     |primary |  |secondary    |primary | |secondary
  52                     |packet  |  |packet  +    |packet  | |packet  +
  53                     +--------+  +--------+    +--------+ +--------+
  54                         |           |             |          |
  55                     +---v----+  +---v----+    +---v----+ +---v----+
  56                     |primary |  |secondary    |primary | |secondary
  57                     |packet  |  |packet  +    |packet  | |packet  +
  58                     +--------+  +--------+    +--------+ +--------+
  59                         |           |             |          |
  60                     +---v----+  +---v----+    +---v----+ +---v----+
  61                     |primary |  |secondary    |primary | |secondary
  62                     |packet  |  |packet  +    |packet  | |packet  +
  63                     +--------+  +--------+    +--------+ +--------+
  64 */
  65 typedef struct CompareState {
  66     Object parent;
  67
  68     char *pri_indev;
  69     char *sec_indev;
  70     char *outdev;
  71     CharBackend chr_pri_in;
  72     CharBackend chr_sec_in;
  73     CharBackend chr_out;
  74     SocketReadState pri_rs;
  75     SocketReadState sec_rs;
  76
  77     /* connection list: the connections belonged to this NIC could be found
  78      * in this list.
  79      * element type: Connection
  80      */
  81     GQueue conn_list;
  82     /* hashtable to save connection */
  83     GHashTable *connection_track_table;
  84     /* compare thread, a thread for each NIC */
  85     QemuThread thread;
  86 } CompareState;
  87
  88 typedef struct CompareClass {
  89     ObjectClass parent_class;
  90 } CompareClass;
  91
  92 enum {
  93     PRIMARY_IN = 0,
  94     SECONDARY_IN,
  95 };
  96
  97 static int compare_chr_send(CharBackend *out,
  98                             const uint8_t *buf,
  99                             uint32_t size);
 100
 101 static gint seq_sorter(Packet *a, Packet *b, gpointer data)
 102 {
 103     struct tcphdr *atcp, *btcp;
 104
 105     atcp = (struct tcphdr *)(a->transport_header);
 106     btcp = (struct tcphdr *)(b->transport_header);
 107     return ntohl(atcp->th_seq) - ntohl(btcp->th_seq);
 108 }
 109
 110 /*
 111  * Return 0 on success, if return -1 means the pkt
 112  * is unsupported(arp and ipv6) and will be sent later
 113  */
 114 static int packet_enqueue(CompareState *s, int mode)
 115 {
 116     ConnectionKey key;
 117     Packet *pkt = NULL;
 118     Connection *conn;
 119
 120     if (mode == PRIMARY_IN) {
 121         pkt = packet_new(s->pri_rs.buf, s->pri_rs.packet_len);
 122     } else {
 123         pkt = packet_new(s->sec_rs.buf, s->sec_rs.packet_len);
 124     }
 125
 126     if (parse_packet_early(pkt)) {
 127         packet_destroy(pkt, NULL);
 128         pkt = NULL;
 129         return -1;
 130     }
 131     fill_connection_key(pkt, &key);
 132
 133     conn = connection_get(s->connection_track_table,
 134                           &key,
 135                           &s->conn_list);
 136
 137     if (!conn->processing) {
 138         g_queue_push_tail(&s->conn_list, conn);
 139         conn->processing = true;
 140     }
 141
 142     if (mode == PRIMARY_IN) {
 143         if (g_queue_get_length(&conn->primary_list) <=
 144                                MAX_QUEUE_SIZE) {
 145             g_queue_push_tail(&conn->primary_list, pkt);
 146             if (conn->ip_proto == IPPROTO_TCP) {
 147                 g_queue_sort(&conn->primary_list,
 148                              (GCompareDataFunc)seq_sorter,
 149                              NULL);
 150             }
 151         } else {
 152             error_report("colo compare primary queue size too big,"
 153                          "drop packet");
 154         }
 155     } else {
 156         if (g_queue_get_length(&conn->secondary_list) <=
 157                                MAX_QUEUE_SIZE) {
 158             g_queue_push_tail(&conn->secondary_list, pkt);
 159             if (conn->ip_proto == IPPROTO_TCP) {
 160                 g_queue_sort(&conn->secondary_list,
 161                              (GCompareDataFunc)seq_sorter,
 162                              NULL);
 163             }
 164         } else {
 165             error_report("colo compare secondary queue size too big,"
 166                          "drop packet");
 167         }
 168     }
 169
 170     return 0;
 171 }
 172
 173 /*
 174  * The IP packets sent by primary and secondary
 175  * will be compared in here
 176  * TODO support ip fragment, Out-Of-Order
 177  * return:    0  means packet same
 178  *            > 0 || < 0 means packet different
 179  */
 180 static int colo_packet_compare(Packet *ppkt, Packet *spkt)
 181 {
 182     trace_colo_compare_ip_info(ppkt->size, inet_ntoa(ppkt->ip->ip_src),
 183                                inet_ntoa(ppkt->ip->ip_dst), spkt->size,
 184                                inet_ntoa(spkt->ip->ip_src),
 185                                inet_ntoa(spkt->ip->ip_dst));
 186
 187     if (ppkt->size == spkt->size) {
 188         return memcmp(ppkt->data, spkt->data, spkt->size);
 189     } else {
 190         return -1;
 191     }
 192 }
 193
 194 /*
 195  * Called from the compare thread on the primary
 196  * for compare tcp packet
 197  * compare_tcp copied from Dr. David Alan Gilbert's branch
 198  */
 199 static int colo_packet_compare_tcp(Packet *spkt, Packet *ppkt)
 200 {
 201     struct tcphdr *ptcp, *stcp;
 202     int res;
 203
 204     trace_colo_compare_main("compare tcp");
 205     if (ppkt->size != spkt->size) {
 206         if (trace_event_get_state(TRACE_COLO_COMPARE_MISCOMPARE)) {
 207             trace_colo_compare_main("pkt size not same");
 208         }
 209         return -1;
 210     }
 211
 212     ptcp = (struct tcphdr *)ppkt->transport_header;
 213     stcp = (struct tcphdr *)spkt->transport_header;
 214
 215     /*
 216      * The 'identification' field in the IP header is *very* random
 217      * it almost never matches.  Fudge this by ignoring differences in
 218      * unfragmented packets; they'll normally sort themselves out if different
 219      * anyway, and it should recover at the TCP level.
 220      * An alternative would be to get both the primary and secondary to rewrite
 221      * somehow; but that would need some sync traffic to sync the state
 222      */
 223     if (ntohs(ppkt->ip->ip_off) & IP_DF) {
 224         spkt->ip->ip_id = ppkt->ip->ip_id;
 225         /* and the sum will be different if the IDs were different */
 226         spkt->ip->ip_sum = ppkt->ip->ip_sum;
 227     }
 228
 229     res = memcmp(ppkt->data + ETH_HLEN, spkt->data + ETH_HLEN,
 230                 (spkt->size - ETH_HLEN));
 231
 232     if (res != 0 && trace_event_get_state(TRACE_COLO_COMPARE_MISCOMPARE)) {
 233         trace_colo_compare_pkt_info_src(inet_ntoa(ppkt->ip->ip_src),
 234                                         ntohl(stcp->th_seq),
 235                                         ntohl(stcp->th_ack),
 236                                         res, stcp->th_flags,
 237                                         spkt->size);
 238
 239         trace_colo_compare_pkt_info_dst(inet_ntoa(ppkt->ip->ip_dst),
 240                                         ntohl(ptcp->th_seq),
 241                                         ntohl(ptcp->th_ack),
 242                                         res, ptcp->th_flags,
 243                                         ppkt->size);
 244
 245         qemu_hexdump((char *)ppkt->data, stderr,
 246                      "colo-compare ppkt", ppkt->size);
 247         qemu_hexdump((char *)spkt->data, stderr,
 248                      "colo-compare spkt", spkt->size);
 249     }
 250
 251     return res;
 252 }
 253
 254 /*
 255  * Called from the compare thread on the primary
 256  * for compare udp packet
 257  */
 258 static int colo_packet_compare_udp(Packet *spkt, Packet *ppkt)
 259 {
 260     int ret;
 261
 262     trace_colo_compare_main("compare udp");
 263     ret = colo_packet_compare(ppkt, spkt);
 264
 265     if (ret) {
 266         trace_colo_compare_udp_miscompare("primary pkt size", ppkt->size);
 267         qemu_hexdump((char *)ppkt->data, stderr, "colo-compare", ppkt->size);
 268         trace_colo_compare_udp_miscompare("Secondary pkt size", spkt->size);
 269         qemu_hexdump((char *)spkt->data, stderr, "colo-compare", spkt->size);
 270     }
 271
 272     return ret;
 273 }
 274
 275 /*
 276  * Called from the compare thread on the primary
 277  * for compare icmp packet
 278  */
 279 static int colo_packet_compare_icmp(Packet *spkt, Packet *ppkt)
 280 {
 281     int network_length;
 282
 283     trace_colo_compare_main("compare icmp");
 284     network_length = ppkt->ip->ip_hl * 4;
 285     if (ppkt->size != spkt->size ||
 286         ppkt->size < network_length + ETH_HLEN) {
 287         return -1;
 288     }
 289
 290     if (colo_packet_compare(ppkt, spkt)) {
 291         trace_colo_compare_icmp_miscompare("primary pkt size",
 292                                            ppkt->size);
 293         qemu_hexdump((char *)ppkt->data, stderr, "colo-compare",
 294                      ppkt->size);
 295         trace_colo_compare_icmp_miscompare("Secondary pkt size",
 296                                            spkt->size);
 297         qemu_hexdump((char *)spkt->data, stderr, "colo-compare",
 298                      spkt->size);
 299         return -1;
 300     } else {
 301         return 0;
 302     }
 303 }
 304
 305 /*
 306  * Called from the compare thread on the primary
 307  * for compare other packet
 308  */
 309 static int colo_packet_compare_other(Packet *spkt, Packet *ppkt)
 310 {
 311     trace_colo_compare_main("compare other");
 312     trace_colo_compare_ip_info(ppkt->size, inet_ntoa(ppkt->ip->ip_src),
 313                                inet_ntoa(ppkt->ip->ip_dst), spkt->size,
 314                                inet_ntoa(spkt->ip->ip_src),
 315                                inet_ntoa(spkt->ip->ip_dst));
 316     return colo_packet_compare(ppkt, spkt);
 317 }
 318
 319 static int colo_old_packet_check_one(Packet *pkt, int64_t *check_time)
 320 {
 321     int64_t now = qemu_clock_get_ms(QEMU_CLOCK_HOST);
 322
 323     if ((now - pkt->creation_ms) > (*check_time)) {
 324         trace_colo_old_packet_check_found(pkt->creation_ms);
 325         return 0;
 326     } else {
 327         return 1;
 328     }
 329 }
 330
 331 static void colo_old_packet_check_one_conn(void *opaque,
 332                                            void *user_data)
 333 {
 334     Connection *conn = opaque;
 335     GList *result = NULL;
 336     int64_t check_time = REGULAR_PACKET_CHECK_MS;
 337
 338     result = g_queue_find_custom(&conn->primary_list,
 339                                  &check_time,
 340                                  (GCompareFunc)colo_old_packet_check_one);
 341
 342     if (result) {
 343         /* do checkpoint will flush old packet */
 344         /* TODO: colo_notify_checkpoint();*/
 345     }
 346 }
 347
 348 /*
 349  * Look for old packets that the secondary hasn't matched,
 350  * if we have some then we have to checkpoint to wake
 351  * the secondary up.
 352  */
 353 static void colo_old_packet_check(void *opaque)
 354 {
 355     CompareState *s = opaque;
 356
 357     g_queue_foreach(&s->conn_list, colo_old_packet_check_one_conn, NULL);
 358 }
 359
 360 /*
 361  * Called from the compare thread on the primary
 362  * for compare connection
 363  */
 364 static void colo_compare_connection(void *opaque, void *user_data)
 365 {
 366     CompareState *s = user_data;
 367     Connection *conn = opaque;
 368     Packet *pkt = NULL;
 369     GList *result = NULL;
 370     int ret;
 371
 372     while (!g_queue_is_empty(&conn->primary_list) &&
 373            !g_queue_is_empty(&conn->secondary_list)) {
 374         pkt = g_queue_pop_tail(&conn->primary_list);
 375         switch (conn->ip_proto) {
 376         case IPPROTO_TCP:
 377             result = g_queue_find_custom(&conn->secondary_list,
 378                      pkt, (GCompareFunc)colo_packet_compare_tcp);
 379             break;
 380         case IPPROTO_UDP:
 381             result = g_queue_find_custom(&conn->secondary_list,
 382                      pkt, (GCompareFunc)colo_packet_compare_udp);
 383             break;
 384         case IPPROTO_ICMP:
 385             result = g_queue_find_custom(&conn->secondary_list,
 386                      pkt, (GCompareFunc)colo_packet_compare_icmp);
 387             break;
 388         default:
 389             result = g_queue_find_custom(&conn->secondary_list,
 390                      pkt, (GCompareFunc)colo_packet_compare_other);
 391             break;
 392         }
 393
 394         if (result) {
 395             ret = compare_chr_send(&s->chr_out, pkt->data, pkt->size);
 396             if (ret < 0) {
 397                 error_report("colo_send_primary_packet failed");
 398             }
 399             trace_colo_compare_main("packet same and release packet");
 400             g_queue_remove(&conn->secondary_list, result->data);
 401             packet_destroy(pkt, NULL);
 402         } else {
 403             /*
 404              * If one packet arrive late, the secondary_list or
 405              * primary_list will be empty, so we can't compare it
 406              * until next comparison.
 407              */
 408             trace_colo_compare_main("packet different");
 409             g_queue_push_tail(&conn->primary_list, pkt);
 410             /* TODO: colo_notify_checkpoint();*/
 411             break;
 412         }
 413     }
 414 }
 415
 416 static int compare_chr_send(CharBackend *out,
 417                             const uint8_t *buf,
 418                             uint32_t size)
 419 {
 420     int ret = 0;
 421     uint32_t len = htonl(size);
 422
 423     if (!size) {
 424         return 0;
 425     }
 426
 427     ret = qemu_chr_fe_write_all(out, (uint8_t *)&len, sizeof(len));
 428     if (ret != sizeof(len)) {
 429         goto err;
 430     }
 431
 432     ret = qemu_chr_fe_write_all(out, (uint8_t *)buf, size);
 433     if (ret != size) {
 434         goto err;
 435     }
 436
 437     return 0;
 438
 439 err:
 440     return ret < 0 ? ret : -EIO;
 441 }
 442
 443 static int compare_chr_can_read(void *opaque)
 444 {
 445     return COMPARE_READ_LEN_MAX;
 446 }
 447
 448 /*
 449  * Called from the main thread on the primary for packets
 450  * arriving over the socket from the primary.
 451  */
 452 static void compare_pri_chr_in(void *opaque, const uint8_t *buf, int size)
 453 {
 454     CompareState *s = COLO_COMPARE(opaque);
 455     int ret;
 456
 457     ret = net_fill_rstate(&s->pri_rs, buf, size);
 458     if (ret == -1) {
 459         qemu_chr_fe_set_handlers(&s->chr_pri_in, NULL, NULL, NULL,
 460                                  NULL, NULL, true);
 461         error_report("colo-compare primary_in error");
 462     }
 463 }
 464
 465 /*
 466  * Called from the main thread on the primary for packets
 467  * arriving over the socket from the secondary.
 468  */
 469 static void compare_sec_chr_in(void *opaque, const uint8_t *buf, int size)
 470 {
 471     CompareState *s = COLO_COMPARE(opaque);
 472     int ret;
 473
 474     ret = net_fill_rstate(&s->sec_rs, buf, size);
 475     if (ret == -1) {
 476         qemu_chr_fe_set_handlers(&s->chr_sec_in, NULL, NULL, NULL,
 477                                  NULL, NULL, true);
 478         error_report("colo-compare secondary_in error");
 479     }
 480 }
 481
 482 /*
 483  * Check old packet regularly so it can watch for any packets
 484  * that the secondary hasn't produced equivalents of.
 485  */
 486 static gboolean check_old_packet_regular(void *opaque)
 487 {
 488     CompareState *s = opaque;
 489
 490     /* if have old packet we will notify checkpoint */
 491     colo_old_packet_check(s);
 492
 493     return TRUE;
 494 }
 495
 496 static void *colo_compare_thread(void *opaque)
 497 {
 498     GMainContext *worker_context;
 499     GMainLoop *compare_loop;
 500     CompareState *s = opaque;
 501     GSource *timeout_source;
 502
 503     worker_context = g_main_context_new();
 504
 505     qemu_chr_fe_set_handlers(&s->chr_pri_in, compare_chr_can_read,
 506                              compare_pri_chr_in, NULL, s, worker_context, true);
 507     qemu_chr_fe_set_handlers(&s->chr_sec_in, compare_chr_can_read,
 508                              compare_sec_chr_in, NULL, s, worker_context, true);
 509
 510     compare_loop = g_main_loop_new(worker_context, FALSE);
 511
 512     /* To kick any packets that the secondary doesn't match */
 513     timeout_source = g_timeout_source_new(REGULAR_PACKET_CHECK_MS);
 514     g_source_set_callback(timeout_source,
 515                           (GSourceFunc)check_old_packet_regular, s, NULL);
 516     g_source_attach(timeout_source, worker_context);
 517
 518     g_main_loop_run(compare_loop);
 519
 520     g_source_unref(timeout_source);
 521     g_main_loop_unref(compare_loop);
 522     g_main_context_unref(worker_context);
 523     return NULL;
 524 }
 525
 526 static char *compare_get_pri_indev(Object *obj, Error **errp)
 527 {
 528     CompareState *s = COLO_COMPARE(obj);
 529
 530     return g_strdup(s->pri_indev);
 531 }
 532
 533 static void compare_set_pri_indev(Object *obj, const char *value, Error **errp)
 534 {
 535     CompareState *s = COLO_COMPARE(obj);
 536
 537     g_free(s->pri_indev);
 538     s->pri_indev = g_strdup(value);
 539 }
 540
 541 static char *compare_get_sec_indev(Object *obj, Error **errp)
 542 {
 543     CompareState *s = COLO_COMPARE(obj);
 544
 545     return g_strdup(s->sec_indev);
 546 }
 547
 548 static void compare_set_sec_indev(Object *obj, const char *value, Error **errp)
 549 {
 550     CompareState *s = COLO_COMPARE(obj);
 551
 552     g_free(s->sec_indev);
 553     s->sec_indev = g_strdup(value);
 554 }
 555
 556 static char *compare_get_outdev(Object *obj, Error **errp)
 557 {
 558     CompareState *s = COLO_COMPARE(obj);
 559
 560     return g_strdup(s->outdev);
 561 }
 562
 563 static void compare_set_outdev(Object *obj, const char *value, Error **errp)
 564 {
 565     CompareState *s = COLO_COMPARE(obj);
 566
 567     g_free(s->outdev);
 568     s->outdev = g_strdup(value);
 569 }
 570
 571 static void compare_pri_rs_finalize(SocketReadState *pri_rs)
 572 {
 573     CompareState *s = container_of(pri_rs, CompareState, pri_rs);
 574
 575     if (packet_enqueue(s, PRIMARY_IN)) {
 576         trace_colo_compare_main("primary: unsupported packet in");
 577         compare_chr_send(&s->chr_out, pri_rs->buf, pri_rs->packet_len);
 578     } else {
 579         /* compare connection */
 580         g_queue_foreach(&s->conn_list, colo_compare_connection, s);
 581     }
 582 }
 583
 584 static void compare_sec_rs_finalize(SocketReadState *sec_rs)
 585 {
 586     CompareState *s = container_of(sec_rs, CompareState, sec_rs);
 587
 588     if (packet_enqueue(s, SECONDARY_IN)) {
 589         trace_colo_compare_main("secondary: unsupported packet in");
 590     } else {
 591         /* compare connection */
 592         g_queue_foreach(&s->conn_list, colo_compare_connection, s);
 593     }
 594 }
 595
 596
 597 /*
 598  * Return 0 is success.
 599  * Return 1 is failed.
 600  */
 601 static int find_and_check_chardev(Chardev **chr,
 602                                   char *chr_name,
 603                                   Error **errp)
 604 {
 605     *chr = qemu_chr_find(chr_name);
 606     if (*chr == NULL) {
 607         error_setg(errp, "Device '%s' not found",
 608                    chr_name);
 609         return 1;
 610     }
 611
 612     if (!qemu_chr_has_feature(*chr, QEMU_CHAR_FEATURE_RECONNECTABLE)) {
 613         error_setg(errp, "chardev \"%s\" is not reconnectable",
 614                    chr_name);
 615         return 1;
 616     }
 617
 618     return 0;
 619 }
 620
 621 /*
 622  * Called from the main thread on the primary
 623  * to setup colo-compare.
 624  */
 625 static void colo_compare_complete(UserCreatable *uc, Error **errp)
 626 {
 627     CompareState *s = COLO_COMPARE(uc);
 628     Chardev *chr;
 629     char thread_name[64];
 630     static int compare_id;
 631
 632     if (!s->pri_indev || !s->sec_indev || !s->outdev) {
 633         error_setg(errp, "colo compare needs 'primary_in' ,"
 634                    "'secondary_in','outdev' property set");
 635         return;
 636     } else if (!strcmp(s->pri_indev, s->outdev) ||
 637                !strcmp(s->sec_indev, s->outdev) ||
 638                !strcmp(s->pri_indev, s->sec_indev)) {
 639         error_setg(errp, "'indev' and 'outdev' could not be same "
 640                    "for compare module");
 641         return;
 642     }
 643
 644     if (find_and_check_chardev(&chr, s->pri_indev, errp) ||
 645         !qemu_chr_fe_init(&s->chr_pri_in, chr, errp)) {
 646         return;
 647     }
 648
 649     if (find_and_check_chardev(&chr, s->sec_indev, errp) ||
 650         !qemu_chr_fe_init(&s->chr_sec_in, chr, errp)) {
 651         return;
 652     }
 653
 654     if (find_and_check_chardev(&chr, s->outdev, errp) ||
 655         !qemu_chr_fe_init(&s->chr_out, chr, errp)) {
 656         return;
 657     }
 658
 659     net_socket_rs_init(&s->pri_rs, compare_pri_rs_finalize);
 660     net_socket_rs_init(&s->sec_rs, compare_sec_rs_finalize);
 661
 662     g_queue_init(&s->conn_list);
 663
 664     s->connection_track_table = g_hash_table_new_full(connection_key_hash,
 665                                                       connection_key_equal,
 666                                                       g_free,
 667                                                       connection_destroy);
 668
 669     sprintf(thread_name, "colo-compare %d", compare_id);
 670     qemu_thread_create(&s->thread, thread_name,
 671                        colo_compare_thread, s,
 672                        QEMU_THREAD_JOINABLE);
 673     compare_id++;
 674
 675     return;
 676 }
 677
 678 static void colo_compare_class_init(ObjectClass *oc, void *data)
 679 {
 680     UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);
 681
 682     ucc->complete = colo_compare_complete;
 683 }
 684
 685 static void colo_compare_init(Object *obj)
 686 {
 687     object_property_add_str(obj, "primary_in",
 688                             compare_get_pri_indev, compare_set_pri_indev,
 689                             NULL);
 690     object_property_add_str(obj, "secondary_in",
 691                             compare_get_sec_indev, compare_set_sec_indev,
 692                             NULL);
 693     object_property_add_str(obj, "outdev",
 694                             compare_get_outdev, compare_set_outdev,
 695                             NULL);
 696 }
 697
 698 static void colo_compare_finalize(Object *obj)
 699 {
 700     CompareState *s = COLO_COMPARE(obj);
 701
 702     qemu_chr_fe_deinit(&s->chr_pri_in);
 703     qemu_chr_fe_deinit(&s->chr_sec_in);
 704     qemu_chr_fe_deinit(&s->chr_out);
 705
 706     g_queue_free(&s->conn_list);
 707
 708     if (qemu_thread_is_self(&s->thread)) {
 709         /* compare connection */
 710         g_queue_foreach(&s->conn_list, colo_compare_connection, s);
 711         qemu_thread_join(&s->thread);
 712     }
 713
 714     g_free(s->pri_indev);
 715     g_free(s->sec_indev);
 716     g_free(s->outdev);
 717 }
 718
 719 static const TypeInfo colo_compare_info = {
 720     .name = TYPE_COLO_COMPARE,
 721     .parent = TYPE_OBJECT,
 722     .instance_size = sizeof(CompareState),
 723     .instance_init = colo_compare_init,
 724     .instance_finalize = colo_compare_finalize,
 725     .class_size = sizeof(CompareClass),
 726     .class_init = colo_compare_class_init,
 727     .interfaces = (InterfaceInfo[]) {
 728         { TYPE_USER_CREATABLE },
 729         { }
 730     }
 731 };
 732
 733 static void register_types(void)
 734 {
 735     type_register_static(&colo_compare_info);
 736 }
 737
 738 type_init(register_types);