xref: /openbmc/qemu/net/colo-compare.c (revision c2b38b27)
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     /* Timer used on the primary to find packets that are never matched */
87     QEMUTimer *timer;
88     QemuMutex timer_check_lock;
89 } CompareState;
90 
91 typedef struct CompareClass {
92     ObjectClass parent_class;
93 } CompareClass;
94 
95 enum {
96     PRIMARY_IN = 0,
97     SECONDARY_IN,
98 };
99 
100 static int compare_chr_send(CharBackend *out,
101                             const uint8_t *buf,
102                             uint32_t size);
103 
104 static gint seq_sorter(Packet *a, Packet *b, gpointer data)
105 {
106     struct tcphdr *atcp, *btcp;
107 
108     atcp = (struct tcphdr *)(a->transport_header);
109     btcp = (struct tcphdr *)(b->transport_header);
110     return ntohl(atcp->th_seq) - ntohl(btcp->th_seq);
111 }
112 
113 /*
114  * Return 0 on success, if return -1 means the pkt
115  * is unsupported(arp and ipv6) and will be sent later
116  */
117 static int packet_enqueue(CompareState *s, int mode)
118 {
119     ConnectionKey key;
120     Packet *pkt = NULL;
121     Connection *conn;
122 
123     if (mode == PRIMARY_IN) {
124         pkt = packet_new(s->pri_rs.buf, s->pri_rs.packet_len);
125     } else {
126         pkt = packet_new(s->sec_rs.buf, s->sec_rs.packet_len);
127     }
128 
129     if (parse_packet_early(pkt)) {
130         packet_destroy(pkt, NULL);
131         pkt = NULL;
132         return -1;
133     }
134     fill_connection_key(pkt, &key);
135 
136     conn = connection_get(s->connection_track_table,
137                           &key,
138                           &s->conn_list);
139 
140     if (!conn->processing) {
141         g_queue_push_tail(&s->conn_list, conn);
142         conn->processing = true;
143     }
144 
145     if (mode == PRIMARY_IN) {
146         if (g_queue_get_length(&conn->primary_list) <=
147                                MAX_QUEUE_SIZE) {
148             g_queue_push_tail(&conn->primary_list, pkt);
149             if (conn->ip_proto == IPPROTO_TCP) {
150                 g_queue_sort(&conn->primary_list,
151                              (GCompareDataFunc)seq_sorter,
152                              NULL);
153             }
154         } else {
155             error_report("colo compare primary queue size too big,"
156                          "drop packet");
157         }
158     } else {
159         if (g_queue_get_length(&conn->secondary_list) <=
160                                MAX_QUEUE_SIZE) {
161             g_queue_push_tail(&conn->secondary_list, pkt);
162             if (conn->ip_proto == IPPROTO_TCP) {
163                 g_queue_sort(&conn->secondary_list,
164                              (GCompareDataFunc)seq_sorter,
165                              NULL);
166             }
167         } else {
168             error_report("colo compare secondary queue size too big,"
169                          "drop packet");
170         }
171     }
172 
173     return 0;
174 }
175 
176 /*
177  * The IP packets sent by primary and secondary
178  * will be compared in here
179  * TODO support ip fragment, Out-Of-Order
180  * return:    0  means packet same
181  *            > 0 || < 0 means packet different
182  */
183 static int colo_packet_compare(Packet *ppkt, Packet *spkt)
184 {
185     trace_colo_compare_ip_info(ppkt->size, inet_ntoa(ppkt->ip->ip_src),
186                                inet_ntoa(ppkt->ip->ip_dst), spkt->size,
187                                inet_ntoa(spkt->ip->ip_src),
188                                inet_ntoa(spkt->ip->ip_dst));
189 
190     if (ppkt->size == spkt->size) {
191         return memcmp(ppkt->data, spkt->data, spkt->size);
192     } else {
193         return -1;
194     }
195 }
196 
197 /*
198  * Called from the compare thread on the primary
199  * for compare tcp packet
200  * compare_tcp copied from Dr. David Alan Gilbert's branch
201  */
202 static int colo_packet_compare_tcp(Packet *spkt, Packet *ppkt)
203 {
204     struct tcphdr *ptcp, *stcp;
205     int res;
206 
207     trace_colo_compare_main("compare tcp");
208     if (ppkt->size != spkt->size) {
209         if (trace_event_get_state(TRACE_COLO_COMPARE_MISCOMPARE)) {
210             trace_colo_compare_main("pkt size not same");
211         }
212         return -1;
213     }
214 
215     ptcp = (struct tcphdr *)ppkt->transport_header;
216     stcp = (struct tcphdr *)spkt->transport_header;
217 
218     /*
219      * The 'identification' field in the IP header is *very* random
220      * it almost never matches.  Fudge this by ignoring differences in
221      * unfragmented packets; they'll normally sort themselves out if different
222      * anyway, and it should recover at the TCP level.
223      * An alternative would be to get both the primary and secondary to rewrite
224      * somehow; but that would need some sync traffic to sync the state
225      */
226     if (ntohs(ppkt->ip->ip_off) & IP_DF) {
227         spkt->ip->ip_id = ppkt->ip->ip_id;
228         /* and the sum will be different if the IDs were different */
229         spkt->ip->ip_sum = ppkt->ip->ip_sum;
230     }
231 
232     res = memcmp(ppkt->data + ETH_HLEN, spkt->data + ETH_HLEN,
233                 (spkt->size - ETH_HLEN));
234 
235     if (res != 0 && trace_event_get_state(TRACE_COLO_COMPARE_MISCOMPARE)) {
236         trace_colo_compare_pkt_info_src(inet_ntoa(ppkt->ip->ip_src),
237                                         ntohl(stcp->th_seq),
238                                         ntohl(stcp->th_ack),
239                                         res, stcp->th_flags,
240                                         spkt->size);
241 
242         trace_colo_compare_pkt_info_dst(inet_ntoa(ppkt->ip->ip_dst),
243                                         ntohl(ptcp->th_seq),
244                                         ntohl(ptcp->th_ack),
245                                         res, ptcp->th_flags,
246                                         ppkt->size);
247 
248         qemu_hexdump((char *)ppkt->data, stderr,
249                      "colo-compare ppkt", ppkt->size);
250         qemu_hexdump((char *)spkt->data, stderr,
251                      "colo-compare spkt", spkt->size);
252     }
253 
254     return res;
255 }
256 
257 /*
258  * Called from the compare thread on the primary
259  * for compare udp packet
260  */
261 static int colo_packet_compare_udp(Packet *spkt, Packet *ppkt)
262 {
263     int ret;
264 
265     trace_colo_compare_main("compare udp");
266     ret = colo_packet_compare(ppkt, spkt);
267 
268     if (ret) {
269         trace_colo_compare_udp_miscompare("primary pkt size", ppkt->size);
270         qemu_hexdump((char *)ppkt->data, stderr, "colo-compare", ppkt->size);
271         trace_colo_compare_udp_miscompare("Secondary pkt size", spkt->size);
272         qemu_hexdump((char *)spkt->data, stderr, "colo-compare", spkt->size);
273     }
274 
275     return ret;
276 }
277 
278 /*
279  * Called from the compare thread on the primary
280  * for compare icmp packet
281  */
282 static int colo_packet_compare_icmp(Packet *spkt, Packet *ppkt)
283 {
284     int network_length;
285 
286     trace_colo_compare_main("compare icmp");
287     network_length = ppkt->ip->ip_hl * 4;
288     if (ppkt->size != spkt->size ||
289         ppkt->size < network_length + ETH_HLEN) {
290         return -1;
291     }
292 
293     if (colo_packet_compare(ppkt, spkt)) {
294         trace_colo_compare_icmp_miscompare("primary pkt size",
295                                            ppkt->size);
296         qemu_hexdump((char *)ppkt->data, stderr, "colo-compare",
297                      ppkt->size);
298         trace_colo_compare_icmp_miscompare("Secondary pkt size",
299                                            spkt->size);
300         qemu_hexdump((char *)spkt->data, stderr, "colo-compare",
301                      spkt->size);
302         return -1;
303     } else {
304         return 0;
305     }
306 }
307 
308 /*
309  * Called from the compare thread on the primary
310  * for compare other packet
311  */
312 static int colo_packet_compare_other(Packet *spkt, Packet *ppkt)
313 {
314     trace_colo_compare_main("compare other");
315     trace_colo_compare_ip_info(ppkt->size, inet_ntoa(ppkt->ip->ip_src),
316                                inet_ntoa(ppkt->ip->ip_dst), spkt->size,
317                                inet_ntoa(spkt->ip->ip_src),
318                                inet_ntoa(spkt->ip->ip_dst));
319     return colo_packet_compare(ppkt, spkt);
320 }
321 
322 static int colo_old_packet_check_one(Packet *pkt, int64_t *check_time)
323 {
324     int64_t now = qemu_clock_get_ms(QEMU_CLOCK_HOST);
325 
326     if ((now - pkt->creation_ms) > (*check_time)) {
327         trace_colo_old_packet_check_found(pkt->creation_ms);
328         return 0;
329     } else {
330         return 1;
331     }
332 }
333 
334 static void colo_old_packet_check_one_conn(void *opaque,
335                                            void *user_data)
336 {
337     Connection *conn = opaque;
338     GList *result = NULL;
339     int64_t check_time = REGULAR_PACKET_CHECK_MS;
340 
341     result = g_queue_find_custom(&conn->primary_list,
342                                  &check_time,
343                                  (GCompareFunc)colo_old_packet_check_one);
344 
345     if (result) {
346         /* do checkpoint will flush old packet */
347         /* TODO: colo_notify_checkpoint();*/
348     }
349 }
350 
351 /*
352  * Look for old packets that the secondary hasn't matched,
353  * if we have some then we have to checkpoint to wake
354  * the secondary up.
355  */
356 static void colo_old_packet_check(void *opaque)
357 {
358     CompareState *s = opaque;
359 
360     g_queue_foreach(&s->conn_list, colo_old_packet_check_one_conn, NULL);
361 }
362 
363 /*
364  * Called from the compare thread on the primary
365  * for compare connection
366  */
367 static void colo_compare_connection(void *opaque, void *user_data)
368 {
369     CompareState *s = user_data;
370     Connection *conn = opaque;
371     Packet *pkt = NULL;
372     GList *result = NULL;
373     int ret;
374 
375     while (!g_queue_is_empty(&conn->primary_list) &&
376            !g_queue_is_empty(&conn->secondary_list)) {
377         qemu_mutex_lock(&s->timer_check_lock);
378         pkt = g_queue_pop_tail(&conn->primary_list);
379         qemu_mutex_unlock(&s->timer_check_lock);
380         switch (conn->ip_proto) {
381         case IPPROTO_TCP:
382             result = g_queue_find_custom(&conn->secondary_list,
383                      pkt, (GCompareFunc)colo_packet_compare_tcp);
384             break;
385         case IPPROTO_UDP:
386             result = g_queue_find_custom(&conn->secondary_list,
387                      pkt, (GCompareFunc)colo_packet_compare_udp);
388             break;
389         case IPPROTO_ICMP:
390             result = g_queue_find_custom(&conn->secondary_list,
391                      pkt, (GCompareFunc)colo_packet_compare_icmp);
392             break;
393         default:
394             result = g_queue_find_custom(&conn->secondary_list,
395                      pkt, (GCompareFunc)colo_packet_compare_other);
396             break;
397         }
398 
399         if (result) {
400             ret = compare_chr_send(&s->chr_out, pkt->data, pkt->size);
401             if (ret < 0) {
402                 error_report("colo_send_primary_packet failed");
403             }
404             trace_colo_compare_main("packet same and release packet");
405             g_queue_remove(&conn->secondary_list, result->data);
406             packet_destroy(pkt, NULL);
407         } else {
408             /*
409              * If one packet arrive late, the secondary_list or
410              * primary_list will be empty, so we can't compare it
411              * until next comparison.
412              */
413             trace_colo_compare_main("packet different");
414             qemu_mutex_lock(&s->timer_check_lock);
415             g_queue_push_tail(&conn->primary_list, pkt);
416             qemu_mutex_unlock(&s->timer_check_lock);
417             /* TODO: colo_notify_checkpoint();*/
418             break;
419         }
420     }
421 }
422 
423 static int compare_chr_send(CharBackend *out,
424                             const uint8_t *buf,
425                             uint32_t size)
426 {
427     int ret = 0;
428     uint32_t len = htonl(size);
429 
430     if (!size) {
431         return 0;
432     }
433 
434     ret = qemu_chr_fe_write_all(out, (uint8_t *)&len, sizeof(len));
435     if (ret != sizeof(len)) {
436         goto err;
437     }
438 
439     ret = qemu_chr_fe_write_all(out, (uint8_t *)buf, size);
440     if (ret != size) {
441         goto err;
442     }
443 
444     return 0;
445 
446 err:
447     return ret < 0 ? ret : -EIO;
448 }
449 
450 static int compare_chr_can_read(void *opaque)
451 {
452     return COMPARE_READ_LEN_MAX;
453 }
454 
455 /*
456  * Called from the main thread on the primary for packets
457  * arriving over the socket from the primary.
458  */
459 static void compare_pri_chr_in(void *opaque, const uint8_t *buf, int size)
460 {
461     CompareState *s = COLO_COMPARE(opaque);
462     int ret;
463 
464     ret = net_fill_rstate(&s->pri_rs, buf, size);
465     if (ret == -1) {
466         qemu_chr_fe_set_handlers(&s->chr_pri_in, NULL, NULL, NULL,
467                                  NULL, NULL, true);
468         error_report("colo-compare primary_in error");
469     }
470 }
471 
472 /*
473  * Called from the main thread on the primary for packets
474  * arriving over the socket from the secondary.
475  */
476 static void compare_sec_chr_in(void *opaque, const uint8_t *buf, int size)
477 {
478     CompareState *s = COLO_COMPARE(opaque);
479     int ret;
480 
481     ret = net_fill_rstate(&s->sec_rs, buf, size);
482     if (ret == -1) {
483         qemu_chr_fe_set_handlers(&s->chr_sec_in, NULL, NULL, NULL,
484                                  NULL, NULL, true);
485         error_report("colo-compare secondary_in error");
486     }
487 }
488 
489 static void *colo_compare_thread(void *opaque)
490 {
491     GMainContext *worker_context;
492     GMainLoop *compare_loop;
493     CompareState *s = opaque;
494 
495     worker_context = g_main_context_new();
496 
497     qemu_chr_fe_set_handlers(&s->chr_pri_in, compare_chr_can_read,
498                              compare_pri_chr_in, NULL, s, worker_context, true);
499     qemu_chr_fe_set_handlers(&s->chr_sec_in, compare_chr_can_read,
500                              compare_sec_chr_in, NULL, s, worker_context, true);
501 
502     compare_loop = g_main_loop_new(worker_context, FALSE);
503 
504     g_main_loop_run(compare_loop);
505 
506     g_main_loop_unref(compare_loop);
507     g_main_context_unref(worker_context);
508     return NULL;
509 }
510 
511 static char *compare_get_pri_indev(Object *obj, Error **errp)
512 {
513     CompareState *s = COLO_COMPARE(obj);
514 
515     return g_strdup(s->pri_indev);
516 }
517 
518 static void compare_set_pri_indev(Object *obj, const char *value, Error **errp)
519 {
520     CompareState *s = COLO_COMPARE(obj);
521 
522     g_free(s->pri_indev);
523     s->pri_indev = g_strdup(value);
524 }
525 
526 static char *compare_get_sec_indev(Object *obj, Error **errp)
527 {
528     CompareState *s = COLO_COMPARE(obj);
529 
530     return g_strdup(s->sec_indev);
531 }
532 
533 static void compare_set_sec_indev(Object *obj, const char *value, Error **errp)
534 {
535     CompareState *s = COLO_COMPARE(obj);
536 
537     g_free(s->sec_indev);
538     s->sec_indev = g_strdup(value);
539 }
540 
541 static char *compare_get_outdev(Object *obj, Error **errp)
542 {
543     CompareState *s = COLO_COMPARE(obj);
544 
545     return g_strdup(s->outdev);
546 }
547 
548 static void compare_set_outdev(Object *obj, const char *value, Error **errp)
549 {
550     CompareState *s = COLO_COMPARE(obj);
551 
552     g_free(s->outdev);
553     s->outdev = g_strdup(value);
554 }
555 
556 static void compare_pri_rs_finalize(SocketReadState *pri_rs)
557 {
558     CompareState *s = container_of(pri_rs, CompareState, pri_rs);
559 
560     if (packet_enqueue(s, PRIMARY_IN)) {
561         trace_colo_compare_main("primary: unsupported packet in");
562         compare_chr_send(&s->chr_out, pri_rs->buf, pri_rs->packet_len);
563     } else {
564         /* compare connection */
565         g_queue_foreach(&s->conn_list, colo_compare_connection, s);
566     }
567 }
568 
569 static void compare_sec_rs_finalize(SocketReadState *sec_rs)
570 {
571     CompareState *s = container_of(sec_rs, CompareState, sec_rs);
572 
573     if (packet_enqueue(s, SECONDARY_IN)) {
574         trace_colo_compare_main("secondary: unsupported packet in");
575     } else {
576         /* compare connection */
577         g_queue_foreach(&s->conn_list, colo_compare_connection, s);
578     }
579 }
580 
581 
582 /*
583  * Return 0 is success.
584  * Return 1 is failed.
585  */
586 static int find_and_check_chardev(Chardev **chr,
587                                   char *chr_name,
588                                   Error **errp)
589 {
590     *chr = qemu_chr_find(chr_name);
591     if (*chr == NULL) {
592         error_setg(errp, "Device '%s' not found",
593                    chr_name);
594         return 1;
595     }
596 
597     if (!qemu_chr_has_feature(*chr, QEMU_CHAR_FEATURE_RECONNECTABLE)) {
598         error_setg(errp, "chardev \"%s\" is not reconnectable",
599                    chr_name);
600         return 1;
601     }
602 
603     return 0;
604 }
605 
606 /*
607  * Check old packet regularly so it can watch for any packets
608  * that the secondary hasn't produced equivalents of.
609  */
610 static void check_old_packet_regular(void *opaque)
611 {
612     CompareState *s = opaque;
613 
614     timer_mod(s->timer, qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) +
615               REGULAR_PACKET_CHECK_MS);
616     /* if have old packet we will notify checkpoint */
617     /*
618      * TODO: Make timer handler run in compare thread
619      * like qemu_chr_add_handlers_full.
620      */
621     qemu_mutex_lock(&s->timer_check_lock);
622     colo_old_packet_check(s);
623     qemu_mutex_unlock(&s->timer_check_lock);
624 }
625 
626 /*
627  * Called from the main thread on the primary
628  * to setup colo-compare.
629  */
630 static void colo_compare_complete(UserCreatable *uc, Error **errp)
631 {
632     CompareState *s = COLO_COMPARE(uc);
633     Chardev *chr;
634     char thread_name[64];
635     static int compare_id;
636 
637     if (!s->pri_indev || !s->sec_indev || !s->outdev) {
638         error_setg(errp, "colo compare needs 'primary_in' ,"
639                    "'secondary_in','outdev' property set");
640         return;
641     } else if (!strcmp(s->pri_indev, s->outdev) ||
642                !strcmp(s->sec_indev, s->outdev) ||
643                !strcmp(s->pri_indev, s->sec_indev)) {
644         error_setg(errp, "'indev' and 'outdev' could not be same "
645                    "for compare module");
646         return;
647     }
648 
649     if (find_and_check_chardev(&chr, s->pri_indev, errp) ||
650         !qemu_chr_fe_init(&s->chr_pri_in, chr, errp)) {
651         return;
652     }
653 
654     if (find_and_check_chardev(&chr, s->sec_indev, errp) ||
655         !qemu_chr_fe_init(&s->chr_sec_in, chr, errp)) {
656         return;
657     }
658 
659     if (find_and_check_chardev(&chr, s->outdev, errp) ||
660         !qemu_chr_fe_init(&s->chr_out, chr, errp)) {
661         return;
662     }
663 
664     net_socket_rs_init(&s->pri_rs, compare_pri_rs_finalize);
665     net_socket_rs_init(&s->sec_rs, compare_sec_rs_finalize);
666 
667     g_queue_init(&s->conn_list);
668     qemu_mutex_init(&s->timer_check_lock);
669 
670     s->connection_track_table = g_hash_table_new_full(connection_key_hash,
671                                                       connection_key_equal,
672                                                       g_free,
673                                                       connection_destroy);
674 
675     sprintf(thread_name, "colo-compare %d", compare_id);
676     qemu_thread_create(&s->thread, thread_name,
677                        colo_compare_thread, s,
678                        QEMU_THREAD_JOINABLE);
679     compare_id++;
680 
681     /* A regular timer to kick any packets that the secondary doesn't match */
682     s->timer = timer_new_ms(QEMU_CLOCK_VIRTUAL, /* Only when guest runs */
683                             check_old_packet_regular, s);
684     timer_mod(s->timer, qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) +
685                         REGULAR_PACKET_CHECK_MS);
686 
687     return;
688 }
689 
690 static void colo_compare_class_init(ObjectClass *oc, void *data)
691 {
692     UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);
693 
694     ucc->complete = colo_compare_complete;
695 }
696 
697 static void colo_compare_init(Object *obj)
698 {
699     object_property_add_str(obj, "primary_in",
700                             compare_get_pri_indev, compare_set_pri_indev,
701                             NULL);
702     object_property_add_str(obj, "secondary_in",
703                             compare_get_sec_indev, compare_set_sec_indev,
704                             NULL);
705     object_property_add_str(obj, "outdev",
706                             compare_get_outdev, compare_set_outdev,
707                             NULL);
708 }
709 
710 static void colo_compare_finalize(Object *obj)
711 {
712     CompareState *s = COLO_COMPARE(obj);
713 
714     qemu_chr_fe_deinit(&s->chr_pri_in);
715     qemu_chr_fe_deinit(&s->chr_sec_in);
716     qemu_chr_fe_deinit(&s->chr_out);
717 
718     g_queue_free(&s->conn_list);
719 
720     if (qemu_thread_is_self(&s->thread)) {
721         /* compare connection */
722         g_queue_foreach(&s->conn_list, colo_compare_connection, s);
723         qemu_thread_join(&s->thread);
724     }
725 
726     if (s->timer) {
727         timer_del(s->timer);
728     }
729 
730     qemu_mutex_destroy(&s->timer_check_lock);
731 
732     g_free(s->pri_indev);
733     g_free(s->sec_indev);
734     g_free(s->outdev);
735 }
736 
737 static const TypeInfo colo_compare_info = {
738     .name = TYPE_COLO_COMPARE,
739     .parent = TYPE_OBJECT,
740     .instance_size = sizeof(CompareState),
741     .instance_init = colo_compare_init,
742     .instance_finalize = colo_compare_finalize,
743     .class_size = sizeof(CompareClass),
744     .class_init = colo_compare_class_init,
745     .interfaces = (InterfaceInfo[]) {
746         { TYPE_USER_CREATABLE },
747         { }
748     }
749 };
750 
751 static void register_types(void)
752 {
753     type_register_static(&colo_compare_info);
754 }
755 
756 type_init(register_types);
757