xref: /openbmc/qemu/net/colo-compare.c (revision 56e2cd24)
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 
87     GMainContext *worker_context;
88     GMainLoop *compare_loop;
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_common(Packet *ppkt, Packet *spkt, int offset)
184 {
185     if (trace_event_get_state(TRACE_COLO_COMPARE_MISCOMPARE)) {
186         char pri_ip_src[20], pri_ip_dst[20], sec_ip_src[20], sec_ip_dst[20];
187 
188         strcpy(pri_ip_src, inet_ntoa(ppkt->ip->ip_src));
189         strcpy(pri_ip_dst, inet_ntoa(ppkt->ip->ip_dst));
190         strcpy(sec_ip_src, inet_ntoa(spkt->ip->ip_src));
191         strcpy(sec_ip_dst, inet_ntoa(spkt->ip->ip_dst));
192 
193         trace_colo_compare_ip_info(ppkt->size, pri_ip_src,
194                                    pri_ip_dst, spkt->size,
195                                    sec_ip_src, sec_ip_dst);
196     }
197 
198     if (ppkt->size == spkt->size) {
199         return memcmp(ppkt->data + offset, spkt->data + offset,
200                       spkt->size - offset);
201     } else {
202         trace_colo_compare_main("Net packet size are not the same");
203         return -1;
204     }
205 }
206 
207 /*
208  * Called from the compare thread on the primary
209  * for compare tcp packet
210  * compare_tcp copied from Dr. David Alan Gilbert's branch
211  */
212 static int colo_packet_compare_tcp(Packet *spkt, Packet *ppkt)
213 {
214     struct tcphdr *ptcp, *stcp;
215     int res;
216 
217     trace_colo_compare_main("compare tcp");
218 
219     ptcp = (struct tcphdr *)ppkt->transport_header;
220     stcp = (struct tcphdr *)spkt->transport_header;
221 
222     /*
223      * The 'identification' field in the IP header is *very* random
224      * it almost never matches.  Fudge this by ignoring differences in
225      * unfragmented packets; they'll normally sort themselves out if different
226      * anyway, and it should recover at the TCP level.
227      * An alternative would be to get both the primary and secondary to rewrite
228      * somehow; but that would need some sync traffic to sync the state
229      */
230     if (ntohs(ppkt->ip->ip_off) & IP_DF) {
231         spkt->ip->ip_id = ppkt->ip->ip_id;
232         /* and the sum will be different if the IDs were different */
233         spkt->ip->ip_sum = ppkt->ip->ip_sum;
234     }
235 
236     if (ptcp->th_sum == stcp->th_sum) {
237         res = colo_packet_compare_common(ppkt, spkt, ETH_HLEN);
238     } else {
239         res = -1;
240     }
241 
242     if (res != 0 && trace_event_get_state(TRACE_COLO_COMPARE_MISCOMPARE)) {
243         trace_colo_compare_pkt_info_src(inet_ntoa(ppkt->ip->ip_src),
244                                         ntohl(stcp->th_seq),
245                                         ntohl(stcp->th_ack),
246                                         res, stcp->th_flags,
247                                         spkt->size);
248 
249         trace_colo_compare_pkt_info_dst(inet_ntoa(ppkt->ip->ip_dst),
250                                         ntohl(ptcp->th_seq),
251                                         ntohl(ptcp->th_ack),
252                                         res, ptcp->th_flags,
253                                         ppkt->size);
254 
255         qemu_hexdump((char *)ppkt->data, stderr,
256                      "colo-compare ppkt", ppkt->size);
257         qemu_hexdump((char *)spkt->data, stderr,
258                      "colo-compare spkt", spkt->size);
259     }
260 
261     return res;
262 }
263 
264 /*
265  * Called from the compare thread on the primary
266  * for compare udp packet
267  */
268 static int colo_packet_compare_udp(Packet *spkt, Packet *ppkt)
269 {
270     int ret;
271     int network_header_length = ppkt->ip->ip_hl * 4;
272 
273     trace_colo_compare_main("compare udp");
274 
275     /*
276      * Because of ppkt and spkt are both in the same connection,
277      * The ppkt's src ip, dst ip, src port, dst port, ip_proto all are
278      * same with spkt. In addition, IP header's Identification is a random
279      * field, we can handle it in IP fragmentation function later.
280      * COLO just concern the response net packet payload from primary guest
281      * and secondary guest are same or not, So we ignored all IP header include
282      * other field like TOS,TTL,IP Checksum. we only need to compare
283      * the ip payload here.
284      */
285     ret = colo_packet_compare_common(ppkt, spkt,
286                                      network_header_length + ETH_HLEN);
287 
288     if (ret) {
289         trace_colo_compare_udp_miscompare("primary pkt size", ppkt->size);
290         trace_colo_compare_udp_miscompare("Secondary pkt size", spkt->size);
291         if (trace_event_get_state(TRACE_COLO_COMPARE_MISCOMPARE)) {
292             qemu_hexdump((char *)ppkt->data, stderr, "colo-compare pri pkt",
293                          ppkt->size);
294             qemu_hexdump((char *)spkt->data, stderr, "colo-compare sec pkt",
295                          spkt->size);
296         }
297     }
298 
299     return ret;
300 }
301 
302 /*
303  * Called from the compare thread on the primary
304  * for compare icmp packet
305  */
306 static int colo_packet_compare_icmp(Packet *spkt, Packet *ppkt)
307 {
308     int network_header_length = ppkt->ip->ip_hl * 4;
309 
310     trace_colo_compare_main("compare icmp");
311 
312     /*
313      * Because of ppkt and spkt are both in the same connection,
314      * The ppkt's src ip, dst ip, src port, dst port, ip_proto all are
315      * same with spkt. In addition, IP header's Identification is a random
316      * field, we can handle it in IP fragmentation function later.
317      * COLO just concern the response net packet payload from primary guest
318      * and secondary guest are same or not, So we ignored all IP header include
319      * other field like TOS,TTL,IP Checksum. we only need to compare
320      * the ip payload here.
321      */
322     if (colo_packet_compare_common(ppkt, spkt,
323                                    network_header_length + ETH_HLEN)) {
324         trace_colo_compare_icmp_miscompare("primary pkt size",
325                                            ppkt->size);
326         trace_colo_compare_icmp_miscompare("Secondary pkt size",
327                                            spkt->size);
328         if (trace_event_get_state(TRACE_COLO_COMPARE_MISCOMPARE)) {
329             qemu_hexdump((char *)ppkt->data, stderr, "colo-compare pri pkt",
330                          ppkt->size);
331             qemu_hexdump((char *)spkt->data, stderr, "colo-compare sec pkt",
332                          spkt->size);
333         }
334         return -1;
335     } else {
336         return 0;
337     }
338 }
339 
340 /*
341  * Called from the compare thread on the primary
342  * for compare other packet
343  */
344 static int colo_packet_compare_other(Packet *spkt, Packet *ppkt)
345 {
346     trace_colo_compare_main("compare other");
347     if (trace_event_get_state(TRACE_COLO_COMPARE_MISCOMPARE)) {
348         char pri_ip_src[20], pri_ip_dst[20], sec_ip_src[20], sec_ip_dst[20];
349 
350         strcpy(pri_ip_src, inet_ntoa(ppkt->ip->ip_src));
351         strcpy(pri_ip_dst, inet_ntoa(ppkt->ip->ip_dst));
352         strcpy(sec_ip_src, inet_ntoa(spkt->ip->ip_src));
353         strcpy(sec_ip_dst, inet_ntoa(spkt->ip->ip_dst));
354 
355         trace_colo_compare_ip_info(ppkt->size, pri_ip_src,
356                                    pri_ip_dst, spkt->size,
357                                    sec_ip_src, sec_ip_dst);
358     }
359 
360     return colo_packet_compare_common(ppkt, spkt, 0);
361 }
362 
363 static int colo_old_packet_check_one(Packet *pkt, int64_t *check_time)
364 {
365     int64_t now = qemu_clock_get_ms(QEMU_CLOCK_HOST);
366 
367     if ((now - pkt->creation_ms) > (*check_time)) {
368         trace_colo_old_packet_check_found(pkt->creation_ms);
369         return 0;
370     } else {
371         return 1;
372     }
373 }
374 
375 static void colo_old_packet_check_one_conn(void *opaque,
376                                            void *user_data)
377 {
378     Connection *conn = opaque;
379     GList *result = NULL;
380     int64_t check_time = REGULAR_PACKET_CHECK_MS;
381 
382     result = g_queue_find_custom(&conn->primary_list,
383                                  &check_time,
384                                  (GCompareFunc)colo_old_packet_check_one);
385 
386     if (result) {
387         /* do checkpoint will flush old packet */
388         /* TODO: colo_notify_checkpoint();*/
389     }
390 }
391 
392 /*
393  * Look for old packets that the secondary hasn't matched,
394  * if we have some then we have to checkpoint to wake
395  * the secondary up.
396  */
397 static void colo_old_packet_check(void *opaque)
398 {
399     CompareState *s = opaque;
400 
401     g_queue_foreach(&s->conn_list, colo_old_packet_check_one_conn, NULL);
402 }
403 
404 /*
405  * Called from the compare thread on the primary
406  * for compare connection
407  */
408 static void colo_compare_connection(void *opaque, void *user_data)
409 {
410     CompareState *s = user_data;
411     Connection *conn = opaque;
412     Packet *pkt = NULL;
413     GList *result = NULL;
414     int ret;
415 
416     while (!g_queue_is_empty(&conn->primary_list) &&
417            !g_queue_is_empty(&conn->secondary_list)) {
418         pkt = g_queue_pop_tail(&conn->primary_list);
419         switch (conn->ip_proto) {
420         case IPPROTO_TCP:
421             result = g_queue_find_custom(&conn->secondary_list,
422                      pkt, (GCompareFunc)colo_packet_compare_tcp);
423             break;
424         case IPPROTO_UDP:
425             result = g_queue_find_custom(&conn->secondary_list,
426                      pkt, (GCompareFunc)colo_packet_compare_udp);
427             break;
428         case IPPROTO_ICMP:
429             result = g_queue_find_custom(&conn->secondary_list,
430                      pkt, (GCompareFunc)colo_packet_compare_icmp);
431             break;
432         default:
433             result = g_queue_find_custom(&conn->secondary_list,
434                      pkt, (GCompareFunc)colo_packet_compare_other);
435             break;
436         }
437 
438         if (result) {
439             ret = compare_chr_send(&s->chr_out, pkt->data, pkt->size);
440             if (ret < 0) {
441                 error_report("colo_send_primary_packet failed");
442             }
443             trace_colo_compare_main("packet same and release packet");
444             g_queue_remove(&conn->secondary_list, result->data);
445             packet_destroy(pkt, NULL);
446         } else {
447             /*
448              * If one packet arrive late, the secondary_list or
449              * primary_list will be empty, so we can't compare it
450              * until next comparison.
451              */
452             trace_colo_compare_main("packet different");
453             g_queue_push_tail(&conn->primary_list, pkt);
454             /* TODO: colo_notify_checkpoint();*/
455             break;
456         }
457     }
458 }
459 
460 static int compare_chr_send(CharBackend *out,
461                             const uint8_t *buf,
462                             uint32_t size)
463 {
464     int ret = 0;
465     uint32_t len = htonl(size);
466 
467     if (!size) {
468         return 0;
469     }
470 
471     ret = qemu_chr_fe_write_all(out, (uint8_t *)&len, sizeof(len));
472     if (ret != sizeof(len)) {
473         goto err;
474     }
475 
476     ret = qemu_chr_fe_write_all(out, (uint8_t *)buf, size);
477     if (ret != size) {
478         goto err;
479     }
480 
481     return 0;
482 
483 err:
484     return ret < 0 ? ret : -EIO;
485 }
486 
487 static int compare_chr_can_read(void *opaque)
488 {
489     return COMPARE_READ_LEN_MAX;
490 }
491 
492 /*
493  * Called from the main thread on the primary for packets
494  * arriving over the socket from the primary.
495  */
496 static void compare_pri_chr_in(void *opaque, const uint8_t *buf, int size)
497 {
498     CompareState *s = COLO_COMPARE(opaque);
499     int ret;
500 
501     ret = net_fill_rstate(&s->pri_rs, buf, size);
502     if (ret == -1) {
503         qemu_chr_fe_set_handlers(&s->chr_pri_in, NULL, NULL, NULL,
504                                  NULL, NULL, true);
505         error_report("colo-compare primary_in error");
506     }
507 }
508 
509 /*
510  * Called from the main thread on the primary for packets
511  * arriving over the socket from the secondary.
512  */
513 static void compare_sec_chr_in(void *opaque, const uint8_t *buf, int size)
514 {
515     CompareState *s = COLO_COMPARE(opaque);
516     int ret;
517 
518     ret = net_fill_rstate(&s->sec_rs, buf, size);
519     if (ret == -1) {
520         qemu_chr_fe_set_handlers(&s->chr_sec_in, NULL, NULL, NULL,
521                                  NULL, NULL, true);
522         error_report("colo-compare secondary_in error");
523     }
524 }
525 
526 /*
527  * Check old packet regularly so it can watch for any packets
528  * that the secondary hasn't produced equivalents of.
529  */
530 static gboolean check_old_packet_regular(void *opaque)
531 {
532     CompareState *s = opaque;
533 
534     /* if have old packet we will notify checkpoint */
535     colo_old_packet_check(s);
536 
537     return TRUE;
538 }
539 
540 static void *colo_compare_thread(void *opaque)
541 {
542     CompareState *s = opaque;
543     GSource *timeout_source;
544 
545     s->worker_context = g_main_context_new();
546 
547     qemu_chr_fe_set_handlers(&s->chr_pri_in, compare_chr_can_read,
548                           compare_pri_chr_in, NULL, s, s->worker_context, true);
549     qemu_chr_fe_set_handlers(&s->chr_sec_in, compare_chr_can_read,
550                           compare_sec_chr_in, NULL, s, s->worker_context, true);
551 
552     s->compare_loop = g_main_loop_new(s->worker_context, FALSE);
553 
554     /* To kick any packets that the secondary doesn't match */
555     timeout_source = g_timeout_source_new(REGULAR_PACKET_CHECK_MS);
556     g_source_set_callback(timeout_source,
557                           (GSourceFunc)check_old_packet_regular, s, NULL);
558     g_source_attach(timeout_source, s->worker_context);
559 
560     g_main_loop_run(s->compare_loop);
561 
562     g_source_unref(timeout_source);
563     g_main_loop_unref(s->compare_loop);
564     g_main_context_unref(s->worker_context);
565     return NULL;
566 }
567 
568 static char *compare_get_pri_indev(Object *obj, Error **errp)
569 {
570     CompareState *s = COLO_COMPARE(obj);
571 
572     return g_strdup(s->pri_indev);
573 }
574 
575 static void compare_set_pri_indev(Object *obj, const char *value, Error **errp)
576 {
577     CompareState *s = COLO_COMPARE(obj);
578 
579     g_free(s->pri_indev);
580     s->pri_indev = g_strdup(value);
581 }
582 
583 static char *compare_get_sec_indev(Object *obj, Error **errp)
584 {
585     CompareState *s = COLO_COMPARE(obj);
586 
587     return g_strdup(s->sec_indev);
588 }
589 
590 static void compare_set_sec_indev(Object *obj, const char *value, Error **errp)
591 {
592     CompareState *s = COLO_COMPARE(obj);
593 
594     g_free(s->sec_indev);
595     s->sec_indev = g_strdup(value);
596 }
597 
598 static char *compare_get_outdev(Object *obj, Error **errp)
599 {
600     CompareState *s = COLO_COMPARE(obj);
601 
602     return g_strdup(s->outdev);
603 }
604 
605 static void compare_set_outdev(Object *obj, const char *value, Error **errp)
606 {
607     CompareState *s = COLO_COMPARE(obj);
608 
609     g_free(s->outdev);
610     s->outdev = g_strdup(value);
611 }
612 
613 static void compare_pri_rs_finalize(SocketReadState *pri_rs)
614 {
615     CompareState *s = container_of(pri_rs, CompareState, pri_rs);
616 
617     if (packet_enqueue(s, PRIMARY_IN)) {
618         trace_colo_compare_main("primary: unsupported packet in");
619         compare_chr_send(&s->chr_out, pri_rs->buf, pri_rs->packet_len);
620     } else {
621         /* compare connection */
622         g_queue_foreach(&s->conn_list, colo_compare_connection, s);
623     }
624 }
625 
626 static void compare_sec_rs_finalize(SocketReadState *sec_rs)
627 {
628     CompareState *s = container_of(sec_rs, CompareState, sec_rs);
629 
630     if (packet_enqueue(s, SECONDARY_IN)) {
631         trace_colo_compare_main("secondary: unsupported packet in");
632     } else {
633         /* compare connection */
634         g_queue_foreach(&s->conn_list, colo_compare_connection, s);
635     }
636 }
637 
638 
639 /*
640  * Return 0 is success.
641  * Return 1 is failed.
642  */
643 static int find_and_check_chardev(Chardev **chr,
644                                   char *chr_name,
645                                   Error **errp)
646 {
647     *chr = qemu_chr_find(chr_name);
648     if (*chr == NULL) {
649         error_setg(errp, "Device '%s' not found",
650                    chr_name);
651         return 1;
652     }
653 
654     if (!qemu_chr_has_feature(*chr, QEMU_CHAR_FEATURE_RECONNECTABLE)) {
655         error_setg(errp, "chardev \"%s\" is not reconnectable",
656                    chr_name);
657         return 1;
658     }
659 
660     return 0;
661 }
662 
663 /*
664  * Called from the main thread on the primary
665  * to setup colo-compare.
666  */
667 static void colo_compare_complete(UserCreatable *uc, Error **errp)
668 {
669     CompareState *s = COLO_COMPARE(uc);
670     Chardev *chr;
671     char thread_name[64];
672     static int compare_id;
673 
674     if (!s->pri_indev || !s->sec_indev || !s->outdev) {
675         error_setg(errp, "colo compare needs 'primary_in' ,"
676                    "'secondary_in','outdev' property set");
677         return;
678     } else if (!strcmp(s->pri_indev, s->outdev) ||
679                !strcmp(s->sec_indev, s->outdev) ||
680                !strcmp(s->pri_indev, s->sec_indev)) {
681         error_setg(errp, "'indev' and 'outdev' could not be same "
682                    "for compare module");
683         return;
684     }
685 
686     if (find_and_check_chardev(&chr, s->pri_indev, errp) ||
687         !qemu_chr_fe_init(&s->chr_pri_in, chr, errp)) {
688         return;
689     }
690 
691     if (find_and_check_chardev(&chr, s->sec_indev, errp) ||
692         !qemu_chr_fe_init(&s->chr_sec_in, chr, errp)) {
693         return;
694     }
695 
696     if (find_and_check_chardev(&chr, s->outdev, errp) ||
697         !qemu_chr_fe_init(&s->chr_out, chr, errp)) {
698         return;
699     }
700 
701     net_socket_rs_init(&s->pri_rs, compare_pri_rs_finalize);
702     net_socket_rs_init(&s->sec_rs, compare_sec_rs_finalize);
703 
704     g_queue_init(&s->conn_list);
705 
706     s->connection_track_table = g_hash_table_new_full(connection_key_hash,
707                                                       connection_key_equal,
708                                                       g_free,
709                                                       connection_destroy);
710 
711     sprintf(thread_name, "colo-compare %d", compare_id);
712     qemu_thread_create(&s->thread, thread_name,
713                        colo_compare_thread, s,
714                        QEMU_THREAD_JOINABLE);
715     compare_id++;
716 
717     return;
718 }
719 
720 static void colo_flush_packets(void *opaque, void *user_data)
721 {
722     CompareState *s = user_data;
723     Connection *conn = opaque;
724     Packet *pkt = NULL;
725 
726     while (!g_queue_is_empty(&conn->primary_list)) {
727         pkt = g_queue_pop_head(&conn->primary_list);
728         compare_chr_send(&s->chr_out, pkt->data, pkt->size);
729         packet_destroy(pkt, NULL);
730     }
731     while (!g_queue_is_empty(&conn->secondary_list)) {
732         pkt = g_queue_pop_head(&conn->secondary_list);
733         packet_destroy(pkt, NULL);
734     }
735 }
736 
737 static void colo_compare_class_init(ObjectClass *oc, void *data)
738 {
739     UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);
740 
741     ucc->complete = colo_compare_complete;
742 }
743 
744 static void colo_compare_init(Object *obj)
745 {
746     object_property_add_str(obj, "primary_in",
747                             compare_get_pri_indev, compare_set_pri_indev,
748                             NULL);
749     object_property_add_str(obj, "secondary_in",
750                             compare_get_sec_indev, compare_set_sec_indev,
751                             NULL);
752     object_property_add_str(obj, "outdev",
753                             compare_get_outdev, compare_set_outdev,
754                             NULL);
755 }
756 
757 static void colo_compare_finalize(Object *obj)
758 {
759     CompareState *s = COLO_COMPARE(obj);
760 
761     qemu_chr_fe_set_handlers(&s->chr_pri_in, NULL, NULL, NULL, NULL,
762                              s->worker_context, true);
763     qemu_chr_fe_set_handlers(&s->chr_sec_in, NULL, NULL, NULL, NULL,
764                              s->worker_context, true);
765     qemu_chr_fe_deinit(&s->chr_out);
766 
767     g_main_loop_quit(s->compare_loop);
768     qemu_thread_join(&s->thread);
769 
770     /* Release all unhandled packets after compare thead exited */
771     g_queue_foreach(&s->conn_list, colo_flush_packets, s);
772 
773     g_queue_clear(&s->conn_list);
774 
775     g_hash_table_destroy(s->connection_track_table);
776     g_free(s->pri_indev);
777     g_free(s->sec_indev);
778     g_free(s->outdev);
779 }
780 
781 static const TypeInfo colo_compare_info = {
782     .name = TYPE_COLO_COMPARE,
783     .parent = TYPE_OBJECT,
784     .instance_size = sizeof(CompareState),
785     .instance_init = colo_compare_init,
786     .instance_finalize = colo_compare_finalize,
787     .class_size = sizeof(CompareClass),
788     .class_init = colo_compare_class_init,
789     .interfaces = (InterfaceInfo[]) {
790         { TYPE_USER_CREATABLE },
791         { }
792     }
793 };
794 
795 static void register_types(void)
796 {
797     type_register_static(&colo_compare_info);
798 }
799 
800 type_init(register_types);
801