xref: /openbmc/qemu/net/colo-compare.c (revision 0c4266ef)
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-common.h"
17 #include "qemu/error-report.h"
18 #include "trace.h"
19 #include "qapi/error.h"
20 #include "net/net.h"
21 #include "net/eth.h"
22 #include "qom/object_interfaces.h"
23 #include "qemu/iov.h"
24 #include "qom/object.h"
25 #include "net/queue.h"
26 #include "chardev/char-fe.h"
27 #include "qemu/sockets.h"
28 #include "colo.h"
29 #include "sysemu/iothread.h"
30 #include "net/colo-compare.h"
31 #include "migration/colo.h"
32 #include "migration/migration.h"
33 #include "util.h"
34 
35 #include "block/aio-wait.h"
36 #include "qemu/coroutine.h"
37 
38 #define TYPE_COLO_COMPARE "colo-compare"
39 typedef struct CompareState CompareState;
40 DECLARE_INSTANCE_CHECKER(CompareState, COLO_COMPARE,
41                          TYPE_COLO_COMPARE)
42 
43 static QTAILQ_HEAD(, CompareState) net_compares =
44        QTAILQ_HEAD_INITIALIZER(net_compares);
45 
46 static NotifierList colo_compare_notifiers =
47     NOTIFIER_LIST_INITIALIZER(colo_compare_notifiers);
48 
49 #define COMPARE_READ_LEN_MAX NET_BUFSIZE
50 #define MAX_QUEUE_SIZE 1024
51 
52 #define COLO_COMPARE_FREE_PRIMARY     0x01
53 #define COLO_COMPARE_FREE_SECONDARY   0x02
54 
55 #define REGULAR_PACKET_CHECK_MS 3000
56 #define DEFAULT_TIME_OUT_MS 3000
57 
58 /* #define DEBUG_COLO_PACKETS */
59 
60 static QemuMutex colo_compare_mutex;
61 static bool colo_compare_active;
62 static QemuMutex event_mtx;
63 static QemuCond event_complete_cond;
64 static int event_unhandled_count;
65 static uint32_t max_queue_size;
66 
67 /*
68  *  + CompareState ++
69  *  |               |
70  *  +---------------+   +---------------+         +---------------+
71  *  |   conn list   + - >      conn     + ------- >      conn     + -- > ......
72  *  +---------------+   +---------------+         +---------------+
73  *  |               |     |           |             |          |
74  *  +---------------+ +---v----+  +---v----+    +---v----+ +---v----+
75  *                    |primary |  |secondary    |primary | |secondary
76  *                    |packet  |  |packet  +    |packet  | |packet  +
77  *                    +--------+  +--------+    +--------+ +--------+
78  *                        |           |             |          |
79  *                    +---v----+  +---v----+    +---v----+ +---v----+
80  *                    |primary |  |secondary    |primary | |secondary
81  *                    |packet  |  |packet  +    |packet  | |packet  +
82  *                    +--------+  +--------+    +--------+ +--------+
83  *                        |           |             |          |
84  *                    +---v----+  +---v----+    +---v----+ +---v----+
85  *                    |primary |  |secondary    |primary | |secondary
86  *                    |packet  |  |packet  +    |packet  | |packet  +
87  *                    +--------+  +--------+    +--------+ +--------+
88  */
89 
90 typedef struct SendCo {
91     Coroutine *co;
92     struct CompareState *s;
93     CharBackend *chr;
94     GQueue send_list;
95     bool notify_remote_frame;
96     bool done;
97     int ret;
98 } SendCo;
99 
100 typedef struct SendEntry {
101     uint32_t size;
102     uint32_t vnet_hdr_len;
103     uint8_t *buf;
104 } SendEntry;
105 
106 struct CompareState {
107     Object parent;
108 
109     char *pri_indev;
110     char *sec_indev;
111     char *outdev;
112     char *notify_dev;
113     CharBackend chr_pri_in;
114     CharBackend chr_sec_in;
115     CharBackend chr_out;
116     CharBackend chr_notify_dev;
117     SocketReadState pri_rs;
118     SocketReadState sec_rs;
119     SocketReadState notify_rs;
120     SendCo out_sendco;
121     SendCo notify_sendco;
122     bool vnet_hdr;
123     uint64_t compare_timeout;
124     uint32_t expired_scan_cycle;
125 
126     /*
127      * Record the connection that through the NIC
128      * Element type: Connection
129      */
130     GQueue conn_list;
131     /* Record the connection without repetition */
132     GHashTable *connection_track_table;
133 
134     IOThread *iothread;
135     GMainContext *worker_context;
136     QEMUTimer *packet_check_timer;
137 
138     QEMUBH *event_bh;
139     enum colo_event event;
140 
141     QTAILQ_ENTRY(CompareState) next;
142 };
143 
144 typedef struct CompareClass {
145     ObjectClass parent_class;
146 } CompareClass;
147 
148 enum {
149     PRIMARY_IN = 0,
150     SECONDARY_IN,
151 };
152 
153 static const char *colo_mode[] = {
154     [PRIMARY_IN] = "primary",
155     [SECONDARY_IN] = "secondary",
156 };
157 
158 static int compare_chr_send(CompareState *s,
159                             uint8_t *buf,
160                             uint32_t size,
161                             uint32_t vnet_hdr_len,
162                             bool notify_remote_frame,
163                             bool zero_copy);
164 
165 static bool packet_matches_str(const char *str,
166                                const uint8_t *buf,
167                                uint32_t packet_len)
168 {
169     if (packet_len != strlen(str)) {
170         return false;
171     }
172 
173     return !memcmp(str, buf, strlen(str));
174 }
175 
176 static void notify_remote_frame(CompareState *s)
177 {
178     char msg[] = "DO_CHECKPOINT";
179     int ret = 0;
180 
181     ret = compare_chr_send(s, (uint8_t *)msg, strlen(msg), 0, true, false);
182     if (ret < 0) {
183         error_report("Notify Xen COLO-frame failed");
184     }
185 }
186 
187 static void colo_compare_inconsistency_notify(CompareState *s)
188 {
189     if (s->notify_dev) {
190         notify_remote_frame(s);
191     } else {
192         notifier_list_notify(&colo_compare_notifiers,
193                              migrate_get_current());
194     }
195 }
196 
197 /* Use restricted to colo_insert_packet() */
198 static gint seq_sorter(Packet *a, Packet *b, gpointer data)
199 {
200     return a->tcp_seq - b->tcp_seq;
201 }
202 
203 static void fill_pkt_tcp_info(void *data, uint32_t *max_ack)
204 {
205     Packet *pkt = data;
206     struct tcp_hdr *tcphd;
207 
208     tcphd = (struct tcp_hdr *)pkt->transport_header;
209 
210     pkt->tcp_seq = ntohl(tcphd->th_seq);
211     pkt->tcp_ack = ntohl(tcphd->th_ack);
212     *max_ack = *max_ack > pkt->tcp_ack ? *max_ack : pkt->tcp_ack;
213     pkt->header_size = pkt->transport_header - (uint8_t *)pkt->data
214                        + (tcphd->th_off << 2) - pkt->vnet_hdr_len;
215     pkt->payload_size = pkt->size - pkt->header_size;
216     pkt->seq_end = pkt->tcp_seq + pkt->payload_size;
217     pkt->flags = tcphd->th_flags;
218 }
219 
220 /*
221  * Return 1 on success, if return 0 means the
222  * packet will be dropped
223  */
224 static int colo_insert_packet(GQueue *queue, Packet *pkt, uint32_t *max_ack)
225 {
226     if (g_queue_get_length(queue) <= max_queue_size) {
227         if (pkt->ip->ip_p == IPPROTO_TCP) {
228             fill_pkt_tcp_info(pkt, max_ack);
229             g_queue_insert_sorted(queue,
230                                   pkt,
231                                   (GCompareDataFunc)seq_sorter,
232                                   NULL);
233         } else {
234             g_queue_push_tail(queue, pkt);
235         }
236         return 1;
237     }
238     return 0;
239 }
240 
241 /*
242  * Return 0 on success, if return -1 means the pkt
243  * is unsupported(arp and ipv6) and will be sent later
244  */
245 static int packet_enqueue(CompareState *s, int mode, Connection **con)
246 {
247     ConnectionKey key;
248     Packet *pkt = NULL;
249     Connection *conn;
250     int ret;
251 
252     if (mode == PRIMARY_IN) {
253         pkt = packet_new(s->pri_rs.buf,
254                          s->pri_rs.packet_len,
255                          s->pri_rs.vnet_hdr_len);
256     } else {
257         pkt = packet_new(s->sec_rs.buf,
258                          s->sec_rs.packet_len,
259                          s->sec_rs.vnet_hdr_len);
260     }
261 
262     if (parse_packet_early(pkt)) {
263         packet_destroy(pkt, NULL);
264         pkt = NULL;
265         return -1;
266     }
267     fill_connection_key(pkt, &key);
268 
269     conn = connection_get(s->connection_track_table,
270                           &key,
271                           &s->conn_list);
272 
273     if (!conn->processing) {
274         g_queue_push_tail(&s->conn_list, conn);
275         conn->processing = true;
276     }
277 
278     if (mode == PRIMARY_IN) {
279         ret = colo_insert_packet(&conn->primary_list, pkt, &conn->pack);
280     } else {
281         ret = colo_insert_packet(&conn->secondary_list, pkt, &conn->sack);
282     }
283 
284     if (!ret) {
285         trace_colo_compare_drop_packet(colo_mode[mode],
286             "queue size too big, drop packet");
287         packet_destroy(pkt, NULL);
288         pkt = NULL;
289     }
290 
291     *con = conn;
292 
293     return 0;
294 }
295 
296 static inline bool after(uint32_t seq1, uint32_t seq2)
297 {
298         return (int32_t)(seq1 - seq2) > 0;
299 }
300 
301 static void colo_release_primary_pkt(CompareState *s, Packet *pkt)
302 {
303     int ret;
304     ret = compare_chr_send(s,
305                            pkt->data,
306                            pkt->size,
307                            pkt->vnet_hdr_len,
308                            false,
309                            true);
310     if (ret < 0) {
311         error_report("colo send primary packet failed");
312     }
313     trace_colo_compare_main("packet same and release packet");
314     packet_destroy_partial(pkt, NULL);
315 }
316 
317 /*
318  * The IP packets sent by primary and secondary
319  * will be compared in here
320  * TODO support ip fragment, Out-Of-Order
321  * return:    0  means packet same
322  *            > 0 || < 0 means packet different
323  */
324 static int colo_compare_packet_payload(Packet *ppkt,
325                                        Packet *spkt,
326                                        uint16_t poffset,
327                                        uint16_t soffset,
328                                        uint16_t len)
329 
330 {
331     if (trace_event_get_state_backends(TRACE_COLO_COMPARE_IP_INFO)) {
332         char pri_ip_src[20], pri_ip_dst[20], sec_ip_src[20], sec_ip_dst[20];
333 
334         strcpy(pri_ip_src, inet_ntoa(ppkt->ip->ip_src));
335         strcpy(pri_ip_dst, inet_ntoa(ppkt->ip->ip_dst));
336         strcpy(sec_ip_src, inet_ntoa(spkt->ip->ip_src));
337         strcpy(sec_ip_dst, inet_ntoa(spkt->ip->ip_dst));
338 
339         trace_colo_compare_ip_info(ppkt->size, pri_ip_src,
340                                    pri_ip_dst, spkt->size,
341                                    sec_ip_src, sec_ip_dst);
342     }
343 
344     return memcmp(ppkt->data + poffset, spkt->data + soffset, len);
345 }
346 
347 /*
348  * return true means that the payload is consist and
349  * need to make the next comparison, false means do
350  * the checkpoint
351 */
352 static bool colo_mark_tcp_pkt(Packet *ppkt, Packet *spkt,
353                               int8_t *mark, uint32_t max_ack)
354 {
355     *mark = 0;
356 
357     if (ppkt->tcp_seq == spkt->tcp_seq && ppkt->seq_end == spkt->seq_end) {
358         if (!colo_compare_packet_payload(ppkt, spkt,
359                                         ppkt->header_size, spkt->header_size,
360                                         ppkt->payload_size)) {
361             *mark = COLO_COMPARE_FREE_SECONDARY | COLO_COMPARE_FREE_PRIMARY;
362             return true;
363         }
364     }
365 
366     /* one part of secondary packet payload still need to be compared */
367     if (!after(ppkt->seq_end, spkt->seq_end)) {
368         if (!colo_compare_packet_payload(ppkt, spkt,
369                                         ppkt->header_size + ppkt->offset,
370                                         spkt->header_size + spkt->offset,
371                                         ppkt->payload_size - ppkt->offset)) {
372             if (!after(ppkt->tcp_ack, max_ack)) {
373                 *mark = COLO_COMPARE_FREE_PRIMARY;
374                 spkt->offset += ppkt->payload_size - ppkt->offset;
375                 return true;
376             } else {
377                 /* secondary guest hasn't ack the data, don't send
378                  * out this packet
379                  */
380                 return false;
381             }
382         }
383     } else {
384         /* primary packet is longer than secondary packet, compare
385          * the same part and mark the primary packet offset
386          */
387         if (!colo_compare_packet_payload(ppkt, spkt,
388                                         ppkt->header_size + ppkt->offset,
389                                         spkt->header_size + spkt->offset,
390                                         spkt->payload_size - spkt->offset)) {
391             *mark = COLO_COMPARE_FREE_SECONDARY;
392             ppkt->offset += spkt->payload_size - spkt->offset;
393             return true;
394         }
395     }
396 
397     return false;
398 }
399 
400 static void colo_compare_tcp(CompareState *s, Connection *conn)
401 {
402     Packet *ppkt = NULL, *spkt = NULL;
403     int8_t mark;
404 
405     /*
406      * If ppkt and spkt have the same payload, but ppkt's ACK
407      * is greater than spkt's ACK, in this case we can not
408      * send the ppkt because it will cause the secondary guest
409      * to miss sending some data in the next. Therefore, we
410      * record the maximum ACK in the current queue at both
411      * primary side and secondary side. Only when the ack is
412      * less than the smaller of the two maximum ack, then we
413      * can ensure that the packet's payload is acknowledged by
414      * primary and secondary.
415     */
416     uint32_t min_ack = conn->pack > conn->sack ? conn->sack : conn->pack;
417 
418 pri:
419     if (g_queue_is_empty(&conn->primary_list)) {
420         return;
421     }
422     ppkt = g_queue_pop_head(&conn->primary_list);
423 sec:
424     if (g_queue_is_empty(&conn->secondary_list)) {
425         g_queue_push_head(&conn->primary_list, ppkt);
426         return;
427     }
428     spkt = g_queue_pop_head(&conn->secondary_list);
429 
430     if (ppkt->tcp_seq == ppkt->seq_end) {
431         colo_release_primary_pkt(s, ppkt);
432         ppkt = NULL;
433     }
434 
435     if (ppkt && conn->compare_seq && !after(ppkt->seq_end, conn->compare_seq)) {
436         trace_colo_compare_main("pri: this packet has compared");
437         colo_release_primary_pkt(s, ppkt);
438         ppkt = NULL;
439     }
440 
441     if (spkt->tcp_seq == spkt->seq_end) {
442         packet_destroy(spkt, NULL);
443         if (!ppkt) {
444             goto pri;
445         } else {
446             goto sec;
447         }
448     } else {
449         if (conn->compare_seq && !after(spkt->seq_end, conn->compare_seq)) {
450             trace_colo_compare_main("sec: this packet has compared");
451             packet_destroy(spkt, NULL);
452             if (!ppkt) {
453                 goto pri;
454             } else {
455                 goto sec;
456             }
457         }
458         if (!ppkt) {
459             g_queue_push_head(&conn->secondary_list, spkt);
460             goto pri;
461         }
462     }
463 
464     if (colo_mark_tcp_pkt(ppkt, spkt, &mark, min_ack)) {
465         trace_colo_compare_tcp_info("pri",
466                                     ppkt->tcp_seq, ppkt->tcp_ack,
467                                     ppkt->header_size, ppkt->payload_size,
468                                     ppkt->offset, ppkt->flags);
469 
470         trace_colo_compare_tcp_info("sec",
471                                     spkt->tcp_seq, spkt->tcp_ack,
472                                     spkt->header_size, spkt->payload_size,
473                                     spkt->offset, spkt->flags);
474 
475         if (mark == COLO_COMPARE_FREE_PRIMARY) {
476             conn->compare_seq = ppkt->seq_end;
477             colo_release_primary_pkt(s, ppkt);
478             g_queue_push_head(&conn->secondary_list, spkt);
479             goto pri;
480         } else if (mark == COLO_COMPARE_FREE_SECONDARY) {
481             conn->compare_seq = spkt->seq_end;
482             packet_destroy(spkt, NULL);
483             goto sec;
484         } else if (mark == (COLO_COMPARE_FREE_PRIMARY | COLO_COMPARE_FREE_SECONDARY)) {
485             conn->compare_seq = ppkt->seq_end;
486             colo_release_primary_pkt(s, ppkt);
487             packet_destroy(spkt, NULL);
488             goto pri;
489         }
490     } else {
491         g_queue_push_head(&conn->primary_list, ppkt);
492         g_queue_push_head(&conn->secondary_list, spkt);
493 
494 #ifdef DEBUG_COLO_PACKETS
495         qemu_hexdump(stderr, "colo-compare ppkt", ppkt->data, ppkt->size);
496         qemu_hexdump(stderr, "colo-compare spkt", spkt->data, spkt->size);
497 #endif
498 
499         colo_compare_inconsistency_notify(s);
500     }
501 }
502 
503 
504 /*
505  * Called from the compare thread on the primary
506  * for compare udp packet
507  */
508 static int colo_packet_compare_udp(Packet *spkt, Packet *ppkt)
509 {
510     uint16_t network_header_length = ppkt->ip->ip_hl << 2;
511     uint16_t offset = network_header_length + ETH_HLEN + ppkt->vnet_hdr_len;
512 
513     trace_colo_compare_main("compare udp");
514 
515     /*
516      * Because of ppkt and spkt are both in the same connection,
517      * The ppkt's src ip, dst ip, src port, dst port, ip_proto all are
518      * same with spkt. In addition, IP header's Identification is a random
519      * field, we can handle it in IP fragmentation function later.
520      * COLO just concern the response net packet payload from primary guest
521      * and secondary guest are same or not, So we ignored all IP header include
522      * other field like TOS,TTL,IP Checksum. we only need to compare
523      * the ip payload here.
524      */
525     if (ppkt->size != spkt->size) {
526         trace_colo_compare_main("UDP: payload size of packets are different");
527         return -1;
528     }
529     if (colo_compare_packet_payload(ppkt, spkt, offset, offset,
530                                     ppkt->size - offset)) {
531         trace_colo_compare_udp_miscompare("primary pkt size", ppkt->size);
532         trace_colo_compare_udp_miscompare("Secondary pkt size", spkt->size);
533 #ifdef DEBUG_COLO_PACKETS
534         qemu_hexdump(stderr, "colo-compare pri pkt", ppkt->data, ppkt->size);
535         qemu_hexdump(stderr, "colo-compare sec pkt", spkt->data, spkt->size);
536 #endif
537         return -1;
538     } else {
539         return 0;
540     }
541 }
542 
543 /*
544  * Called from the compare thread on the primary
545  * for compare icmp packet
546  */
547 static int colo_packet_compare_icmp(Packet *spkt, Packet *ppkt)
548 {
549     uint16_t network_header_length = ppkt->ip->ip_hl << 2;
550     uint16_t offset = network_header_length + ETH_HLEN + ppkt->vnet_hdr_len;
551 
552     trace_colo_compare_main("compare icmp");
553 
554     /*
555      * Because of ppkt and spkt are both in the same connection,
556      * The ppkt's src ip, dst ip, src port, dst port, ip_proto all are
557      * same with spkt. In addition, IP header's Identification is a random
558      * field, we can handle it in IP fragmentation function later.
559      * COLO just concern the response net packet payload from primary guest
560      * and secondary guest are same or not, So we ignored all IP header include
561      * other field like TOS,TTL,IP Checksum. we only need to compare
562      * the ip payload here.
563      */
564     if (ppkt->size != spkt->size) {
565         trace_colo_compare_main("ICMP: payload size of packets are different");
566         return -1;
567     }
568     if (colo_compare_packet_payload(ppkt, spkt, offset, offset,
569                                     ppkt->size - offset)) {
570         trace_colo_compare_icmp_miscompare("primary pkt size",
571                                            ppkt->size);
572         trace_colo_compare_icmp_miscompare("Secondary pkt size",
573                                            spkt->size);
574 #ifdef DEBUG_COLO_PACKETS
575         qemu_hexdump(stderr, "colo-compare pri pkt", ppkt->data, ppkt->size);
576         qemu_hexdump(stderr, "colo-compare sec pkt", spkt->data, spkt->size);
577 #endif
578         return -1;
579     } else {
580         return 0;
581     }
582 }
583 
584 /*
585  * Called from the compare thread on the primary
586  * for compare other packet
587  */
588 static int colo_packet_compare_other(Packet *spkt, Packet *ppkt)
589 {
590     uint16_t offset = ppkt->vnet_hdr_len;
591 
592     trace_colo_compare_main("compare other");
593     if (trace_event_get_state_backends(TRACE_COLO_COMPARE_IP_INFO)) {
594         char pri_ip_src[20], pri_ip_dst[20], sec_ip_src[20], sec_ip_dst[20];
595 
596         strcpy(pri_ip_src, inet_ntoa(ppkt->ip->ip_src));
597         strcpy(pri_ip_dst, inet_ntoa(ppkt->ip->ip_dst));
598         strcpy(sec_ip_src, inet_ntoa(spkt->ip->ip_src));
599         strcpy(sec_ip_dst, inet_ntoa(spkt->ip->ip_dst));
600 
601         trace_colo_compare_ip_info(ppkt->size, pri_ip_src,
602                                    pri_ip_dst, spkt->size,
603                                    sec_ip_src, sec_ip_dst);
604     }
605 
606     if (ppkt->size != spkt->size) {
607         trace_colo_compare_main("Other: payload size of packets are different");
608         return -1;
609     }
610     return colo_compare_packet_payload(ppkt, spkt, offset, offset,
611                                        ppkt->size - offset);
612 }
613 
614 static int colo_old_packet_check_one(Packet *pkt, int64_t *check_time)
615 {
616     int64_t now = qemu_clock_get_ms(QEMU_CLOCK_HOST);
617 
618     if ((now - pkt->creation_ms) > (*check_time)) {
619         trace_colo_old_packet_check_found(pkt->creation_ms);
620         return 0;
621     } else {
622         return 1;
623     }
624 }
625 
626 void colo_compare_register_notifier(Notifier *notify)
627 {
628     notifier_list_add(&colo_compare_notifiers, notify);
629 }
630 
631 void colo_compare_unregister_notifier(Notifier *notify)
632 {
633     notifier_remove(notify);
634 }
635 
636 static int colo_old_packet_check_one_conn(Connection *conn,
637                                           CompareState *s)
638 {
639     GList *result = NULL;
640 
641     result = g_queue_find_custom(&conn->primary_list,
642                                  &s->compare_timeout,
643                                  (GCompareFunc)colo_old_packet_check_one);
644 
645     if (result) {
646         /* Do checkpoint will flush old packet */
647         colo_compare_inconsistency_notify(s);
648         return 0;
649     }
650 
651     return 1;
652 }
653 
654 /*
655  * Look for old packets that the secondary hasn't matched,
656  * if we have some then we have to checkpoint to wake
657  * the secondary up.
658  */
659 static void colo_old_packet_check(void *opaque)
660 {
661     CompareState *s = opaque;
662 
663     /*
664      * If we find one old packet, stop finding job and notify
665      * COLO frame do checkpoint.
666      */
667     g_queue_find_custom(&s->conn_list, s,
668                         (GCompareFunc)colo_old_packet_check_one_conn);
669 }
670 
671 static void colo_compare_packet(CompareState *s, Connection *conn,
672                                 int (*HandlePacket)(Packet *spkt,
673                                 Packet *ppkt))
674 {
675     Packet *pkt = NULL;
676     GList *result = NULL;
677 
678     while (!g_queue_is_empty(&conn->primary_list) &&
679            !g_queue_is_empty(&conn->secondary_list)) {
680         pkt = g_queue_pop_head(&conn->primary_list);
681         result = g_queue_find_custom(&conn->secondary_list,
682                  pkt, (GCompareFunc)HandlePacket);
683 
684         if (result) {
685             colo_release_primary_pkt(s, pkt);
686             g_queue_remove(&conn->secondary_list, result->data);
687         } else {
688             /*
689              * If one packet arrive late, the secondary_list or
690              * primary_list will be empty, so we can't compare it
691              * until next comparison. If the packets in the list are
692              * timeout, it will trigger a checkpoint request.
693              */
694             trace_colo_compare_main("packet different");
695             g_queue_push_head(&conn->primary_list, pkt);
696 
697             colo_compare_inconsistency_notify(s);
698             break;
699         }
700     }
701 }
702 
703 /*
704  * Called from the compare thread on the primary
705  * for compare packet with secondary list of the
706  * specified connection when a new packet was
707  * queued to it.
708  */
709 static void colo_compare_connection(void *opaque, void *user_data)
710 {
711     CompareState *s = user_data;
712     Connection *conn = opaque;
713 
714     switch (conn->ip_proto) {
715     case IPPROTO_TCP:
716         colo_compare_tcp(s, conn);
717         break;
718     case IPPROTO_UDP:
719         colo_compare_packet(s, conn, colo_packet_compare_udp);
720         break;
721     case IPPROTO_ICMP:
722         colo_compare_packet(s, conn, colo_packet_compare_icmp);
723         break;
724     default:
725         colo_compare_packet(s, conn, colo_packet_compare_other);
726         break;
727     }
728 }
729 
730 static void coroutine_fn _compare_chr_send(void *opaque)
731 {
732     SendCo *sendco = opaque;
733     CompareState *s = sendco->s;
734     int ret = 0;
735 
736     while (!g_queue_is_empty(&sendco->send_list)) {
737         SendEntry *entry = g_queue_pop_tail(&sendco->send_list);
738         uint32_t len = htonl(entry->size);
739 
740         ret = qemu_chr_fe_write_all(sendco->chr, (uint8_t *)&len, sizeof(len));
741 
742         if (ret != sizeof(len)) {
743             g_free(entry->buf);
744             g_slice_free(SendEntry, entry);
745             goto err;
746         }
747 
748         if (!sendco->notify_remote_frame && s->vnet_hdr) {
749             /*
750              * We send vnet header len make other module(like filter-redirector)
751              * know how to parse net packet correctly.
752              */
753             len = htonl(entry->vnet_hdr_len);
754 
755             ret = qemu_chr_fe_write_all(sendco->chr,
756                                         (uint8_t *)&len,
757                                         sizeof(len));
758 
759             if (ret != sizeof(len)) {
760                 g_free(entry->buf);
761                 g_slice_free(SendEntry, entry);
762                 goto err;
763             }
764         }
765 
766         ret = qemu_chr_fe_write_all(sendco->chr,
767                                     (uint8_t *)entry->buf,
768                                     entry->size);
769 
770         if (ret != entry->size) {
771             g_free(entry->buf);
772             g_slice_free(SendEntry, entry);
773             goto err;
774         }
775 
776         g_free(entry->buf);
777         g_slice_free(SendEntry, entry);
778     }
779 
780     sendco->ret = 0;
781     goto out;
782 
783 err:
784     while (!g_queue_is_empty(&sendco->send_list)) {
785         SendEntry *entry = g_queue_pop_tail(&sendco->send_list);
786         g_free(entry->buf);
787         g_slice_free(SendEntry, entry);
788     }
789     sendco->ret = ret < 0 ? ret : -EIO;
790 out:
791     sendco->co = NULL;
792     sendco->done = true;
793     aio_wait_kick();
794 }
795 
796 static int compare_chr_send(CompareState *s,
797                             uint8_t *buf,
798                             uint32_t size,
799                             uint32_t vnet_hdr_len,
800                             bool notify_remote_frame,
801                             bool zero_copy)
802 {
803     SendCo *sendco;
804     SendEntry *entry;
805 
806     if (notify_remote_frame) {
807         sendco = &s->notify_sendco;
808     } else {
809         sendco = &s->out_sendco;
810     }
811 
812     if (!size) {
813         return 0;
814     }
815 
816     entry = g_slice_new(SendEntry);
817     entry->size = size;
818     entry->vnet_hdr_len = vnet_hdr_len;
819     if (zero_copy) {
820         entry->buf = buf;
821     } else {
822         entry->buf = g_malloc(size);
823         memcpy(entry->buf, buf, size);
824     }
825     g_queue_push_head(&sendco->send_list, entry);
826 
827     if (sendco->done) {
828         sendco->co = qemu_coroutine_create(_compare_chr_send, sendco);
829         sendco->done = false;
830         qemu_coroutine_enter(sendco->co);
831         if (sendco->done) {
832             /* report early errors */
833             return sendco->ret;
834         }
835     }
836 
837     /* assume success */
838     return 0;
839 }
840 
841 static int compare_chr_can_read(void *opaque)
842 {
843     return COMPARE_READ_LEN_MAX;
844 }
845 
846 /*
847  * Called from the main thread on the primary for packets
848  * arriving over the socket from the primary.
849  */
850 static void compare_pri_chr_in(void *opaque, const uint8_t *buf, int size)
851 {
852     CompareState *s = COLO_COMPARE(opaque);
853     int ret;
854 
855     ret = net_fill_rstate(&s->pri_rs, buf, size);
856     if (ret == -1) {
857         qemu_chr_fe_set_handlers(&s->chr_pri_in, NULL, NULL, NULL, NULL,
858                                  NULL, NULL, true);
859         error_report("colo-compare primary_in error");
860     }
861 }
862 
863 /*
864  * Called from the main thread on the primary for packets
865  * arriving over the socket from the secondary.
866  */
867 static void compare_sec_chr_in(void *opaque, const uint8_t *buf, int size)
868 {
869     CompareState *s = COLO_COMPARE(opaque);
870     int ret;
871 
872     ret = net_fill_rstate(&s->sec_rs, buf, size);
873     if (ret == -1) {
874         qemu_chr_fe_set_handlers(&s->chr_sec_in, NULL, NULL, NULL, NULL,
875                                  NULL, NULL, true);
876         error_report("colo-compare secondary_in error");
877     }
878 }
879 
880 static void compare_notify_chr(void *opaque, const uint8_t *buf, int size)
881 {
882     CompareState *s = COLO_COMPARE(opaque);
883     int ret;
884 
885     ret = net_fill_rstate(&s->notify_rs, buf, size);
886     if (ret == -1) {
887         qemu_chr_fe_set_handlers(&s->chr_notify_dev, NULL, NULL, NULL, NULL,
888                                  NULL, NULL, true);
889         error_report("colo-compare notify_dev error");
890     }
891 }
892 
893 /*
894  * Check old packet regularly so it can watch for any packets
895  * that the secondary hasn't produced equivalents of.
896  */
897 static void check_old_packet_regular(void *opaque)
898 {
899     CompareState *s = opaque;
900 
901     /* if have old packet we will notify checkpoint */
902     colo_old_packet_check(s);
903     timer_mod(s->packet_check_timer, qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) +
904               s->expired_scan_cycle);
905 }
906 
907 /* Public API, Used for COLO frame to notify compare event */
908 void colo_notify_compares_event(void *opaque, int event, Error **errp)
909 {
910     CompareState *s;
911     qemu_mutex_lock(&colo_compare_mutex);
912 
913     if (!colo_compare_active) {
914         qemu_mutex_unlock(&colo_compare_mutex);
915         return;
916     }
917 
918     qemu_mutex_lock(&event_mtx);
919     QTAILQ_FOREACH(s, &net_compares, next) {
920         s->event = event;
921         qemu_bh_schedule(s->event_bh);
922         event_unhandled_count++;
923     }
924     /* Wait all compare threads to finish handling this event */
925     while (event_unhandled_count > 0) {
926         qemu_cond_wait(&event_complete_cond, &event_mtx);
927     }
928 
929     qemu_mutex_unlock(&event_mtx);
930     qemu_mutex_unlock(&colo_compare_mutex);
931 }
932 
933 static void colo_compare_timer_init(CompareState *s)
934 {
935     AioContext *ctx = iothread_get_aio_context(s->iothread);
936 
937     s->packet_check_timer = aio_timer_new(ctx, QEMU_CLOCK_VIRTUAL,
938                                 SCALE_MS, check_old_packet_regular,
939                                 s);
940     timer_mod(s->packet_check_timer, qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) +
941               s->expired_scan_cycle);
942 }
943 
944 static void colo_compare_timer_del(CompareState *s)
945 {
946     if (s->packet_check_timer) {
947         timer_del(s->packet_check_timer);
948         timer_free(s->packet_check_timer);
949         s->packet_check_timer = NULL;
950     }
951  }
952 
953 static void colo_flush_packets(void *opaque, void *user_data);
954 
955 static void colo_compare_handle_event(void *opaque)
956 {
957     CompareState *s = opaque;
958 
959     switch (s->event) {
960     case COLO_EVENT_CHECKPOINT:
961         g_queue_foreach(&s->conn_list, colo_flush_packets, s);
962         break;
963     case COLO_EVENT_FAILOVER:
964         break;
965     default:
966         break;
967     }
968 
969     qemu_mutex_lock(&event_mtx);
970     assert(event_unhandled_count > 0);
971     event_unhandled_count--;
972     qemu_cond_broadcast(&event_complete_cond);
973     qemu_mutex_unlock(&event_mtx);
974 }
975 
976 static void colo_compare_iothread(CompareState *s)
977 {
978     AioContext *ctx = iothread_get_aio_context(s->iothread);
979     object_ref(OBJECT(s->iothread));
980     s->worker_context = iothread_get_g_main_context(s->iothread);
981 
982     qemu_chr_fe_set_handlers(&s->chr_pri_in, compare_chr_can_read,
983                              compare_pri_chr_in, NULL, NULL,
984                              s, s->worker_context, true);
985     qemu_chr_fe_set_handlers(&s->chr_sec_in, compare_chr_can_read,
986                              compare_sec_chr_in, NULL, NULL,
987                              s, s->worker_context, true);
988     if (s->notify_dev) {
989         qemu_chr_fe_set_handlers(&s->chr_notify_dev, compare_chr_can_read,
990                                  compare_notify_chr, NULL, NULL,
991                                  s, s->worker_context, true);
992     }
993 
994     colo_compare_timer_init(s);
995     s->event_bh = aio_bh_new(ctx, colo_compare_handle_event, s);
996 }
997 
998 static char *compare_get_pri_indev(Object *obj, Error **errp)
999 {
1000     CompareState *s = COLO_COMPARE(obj);
1001 
1002     return g_strdup(s->pri_indev);
1003 }
1004 
1005 static void compare_set_pri_indev(Object *obj, const char *value, Error **errp)
1006 {
1007     CompareState *s = COLO_COMPARE(obj);
1008 
1009     g_free(s->pri_indev);
1010     s->pri_indev = g_strdup(value);
1011 }
1012 
1013 static char *compare_get_sec_indev(Object *obj, Error **errp)
1014 {
1015     CompareState *s = COLO_COMPARE(obj);
1016 
1017     return g_strdup(s->sec_indev);
1018 }
1019 
1020 static void compare_set_sec_indev(Object *obj, const char *value, Error **errp)
1021 {
1022     CompareState *s = COLO_COMPARE(obj);
1023 
1024     g_free(s->sec_indev);
1025     s->sec_indev = g_strdup(value);
1026 }
1027 
1028 static char *compare_get_outdev(Object *obj, Error **errp)
1029 {
1030     CompareState *s = COLO_COMPARE(obj);
1031 
1032     return g_strdup(s->outdev);
1033 }
1034 
1035 static void compare_set_outdev(Object *obj, const char *value, Error **errp)
1036 {
1037     CompareState *s = COLO_COMPARE(obj);
1038 
1039     g_free(s->outdev);
1040     s->outdev = g_strdup(value);
1041 }
1042 
1043 static bool compare_get_vnet_hdr(Object *obj, Error **errp)
1044 {
1045     CompareState *s = COLO_COMPARE(obj);
1046 
1047     return s->vnet_hdr;
1048 }
1049 
1050 static void compare_set_vnet_hdr(Object *obj,
1051                                  bool value,
1052                                  Error **errp)
1053 {
1054     CompareState *s = COLO_COMPARE(obj);
1055 
1056     s->vnet_hdr = value;
1057 }
1058 
1059 static char *compare_get_notify_dev(Object *obj, Error **errp)
1060 {
1061     CompareState *s = COLO_COMPARE(obj);
1062 
1063     return g_strdup(s->notify_dev);
1064 }
1065 
1066 static void compare_set_notify_dev(Object *obj, const char *value, Error **errp)
1067 {
1068     CompareState *s = COLO_COMPARE(obj);
1069 
1070     g_free(s->notify_dev);
1071     s->notify_dev = g_strdup(value);
1072 }
1073 
1074 static void compare_get_timeout(Object *obj, Visitor *v,
1075                                 const char *name, void *opaque,
1076                                 Error **errp)
1077 {
1078     CompareState *s = COLO_COMPARE(obj);
1079     uint64_t value = s->compare_timeout;
1080 
1081     visit_type_uint64(v, name, &value, errp);
1082 }
1083 
1084 static void compare_set_timeout(Object *obj, Visitor *v,
1085                                 const char *name, void *opaque,
1086                                 Error **errp)
1087 {
1088     CompareState *s = COLO_COMPARE(obj);
1089     uint32_t value;
1090 
1091     if (!visit_type_uint32(v, name, &value, errp)) {
1092         return;
1093     }
1094     if (!value) {
1095         error_setg(errp, "Property '%s.%s' requires a positive value",
1096                    object_get_typename(obj), name);
1097         return;
1098     }
1099     s->compare_timeout = value;
1100 }
1101 
1102 static void compare_get_expired_scan_cycle(Object *obj, Visitor *v,
1103                                            const char *name, void *opaque,
1104                                            Error **errp)
1105 {
1106     CompareState *s = COLO_COMPARE(obj);
1107     uint32_t value = s->expired_scan_cycle;
1108 
1109     visit_type_uint32(v, name, &value, errp);
1110 }
1111 
1112 static void compare_set_expired_scan_cycle(Object *obj, Visitor *v,
1113                                            const char *name, void *opaque,
1114                                            Error **errp)
1115 {
1116     CompareState *s = COLO_COMPARE(obj);
1117     uint32_t value;
1118 
1119     if (!visit_type_uint32(v, name, &value, errp)) {
1120         return;
1121     }
1122     if (!value) {
1123         error_setg(errp, "Property '%s.%s' requires a positive value",
1124                    object_get_typename(obj), name);
1125         return;
1126     }
1127     s->expired_scan_cycle = value;
1128 }
1129 
1130 static void get_max_queue_size(Object *obj, Visitor *v,
1131                                const char *name, void *opaque,
1132                                Error **errp)
1133 {
1134     uint32_t value = max_queue_size;
1135 
1136     visit_type_uint32(v, name, &value, errp);
1137 }
1138 
1139 static void set_max_queue_size(Object *obj, Visitor *v,
1140                                const char *name, void *opaque,
1141                                Error **errp)
1142 {
1143     Error *local_err = NULL;
1144     uint64_t value;
1145 
1146     visit_type_uint64(v, name, &value, &local_err);
1147     if (local_err) {
1148         goto out;
1149     }
1150     if (!value) {
1151         error_setg(&local_err, "Property '%s.%s' requires a positive value",
1152                    object_get_typename(obj), name);
1153         goto out;
1154     }
1155     max_queue_size = value;
1156 
1157 out:
1158     error_propagate(errp, local_err);
1159 }
1160 
1161 static void compare_pri_rs_finalize(SocketReadState *pri_rs)
1162 {
1163     CompareState *s = container_of(pri_rs, CompareState, pri_rs);
1164     Connection *conn = NULL;
1165 
1166     if (packet_enqueue(s, PRIMARY_IN, &conn)) {
1167         trace_colo_compare_main("primary: unsupported packet in");
1168         compare_chr_send(s,
1169                          pri_rs->buf,
1170                          pri_rs->packet_len,
1171                          pri_rs->vnet_hdr_len,
1172                          false,
1173                          false);
1174     } else {
1175         /* compare packet in the specified connection */
1176         colo_compare_connection(conn, s);
1177     }
1178 }
1179 
1180 static void compare_sec_rs_finalize(SocketReadState *sec_rs)
1181 {
1182     CompareState *s = container_of(sec_rs, CompareState, sec_rs);
1183     Connection *conn = NULL;
1184 
1185     if (packet_enqueue(s, SECONDARY_IN, &conn)) {
1186         trace_colo_compare_main("secondary: unsupported packet in");
1187     } else {
1188         /* compare packet in the specified connection */
1189         colo_compare_connection(conn, s);
1190     }
1191 }
1192 
1193 static void compare_notify_rs_finalize(SocketReadState *notify_rs)
1194 {
1195     CompareState *s = container_of(notify_rs, CompareState, notify_rs);
1196 
1197     const char msg[] = "COLO_COMPARE_GET_XEN_INIT";
1198     int ret;
1199 
1200     if (packet_matches_str("COLO_USERSPACE_PROXY_INIT",
1201                            notify_rs->buf,
1202                            notify_rs->packet_len)) {
1203         ret = compare_chr_send(s, (uint8_t *)msg, strlen(msg), 0, true, false);
1204         if (ret < 0) {
1205             error_report("Notify Xen COLO-frame INIT failed");
1206         }
1207     } else if (packet_matches_str("COLO_CHECKPOINT",
1208                                   notify_rs->buf,
1209                                   notify_rs->packet_len)) {
1210         /* colo-compare do checkpoint, flush pri packet and remove sec packet */
1211         g_queue_foreach(&s->conn_list, colo_flush_packets, s);
1212     } else {
1213         error_report("COLO compare got unsupported instruction");
1214     }
1215 }
1216 
1217 /*
1218  * Return 0 is success.
1219  * Return 1 is failed.
1220  */
1221 static int find_and_check_chardev(Chardev **chr,
1222                                   char *chr_name,
1223                                   Error **errp)
1224 {
1225     *chr = qemu_chr_find(chr_name);
1226     if (*chr == NULL) {
1227         error_setg(errp, "Device '%s' not found",
1228                    chr_name);
1229         return 1;
1230     }
1231 
1232     if (!qemu_chr_has_feature(*chr, QEMU_CHAR_FEATURE_RECONNECTABLE)) {
1233         error_setg(errp, "chardev \"%s\" is not reconnectable",
1234                    chr_name);
1235         return 1;
1236     }
1237 
1238     if (!qemu_chr_has_feature(*chr, QEMU_CHAR_FEATURE_GCONTEXT)) {
1239         error_setg(errp, "chardev \"%s\" cannot switch context",
1240                    chr_name);
1241         return 1;
1242     }
1243 
1244     return 0;
1245 }
1246 
1247 /*
1248  * Called from the main thread on the primary
1249  * to setup colo-compare.
1250  */
1251 static void colo_compare_complete(UserCreatable *uc, Error **errp)
1252 {
1253     CompareState *s = COLO_COMPARE(uc);
1254     Chardev *chr;
1255 
1256     if (!s->pri_indev || !s->sec_indev || !s->outdev || !s->iothread) {
1257         error_setg(errp, "colo compare needs 'primary_in' ,"
1258                    "'secondary_in','outdev','iothread' property set");
1259         return;
1260     } else if (!strcmp(s->pri_indev, s->outdev) ||
1261                !strcmp(s->sec_indev, s->outdev) ||
1262                !strcmp(s->pri_indev, s->sec_indev)) {
1263         error_setg(errp, "'indev' and 'outdev' could not be same "
1264                    "for compare module");
1265         return;
1266     }
1267 
1268     if (!s->compare_timeout) {
1269         /* Set default value to 3000 MS */
1270         s->compare_timeout = DEFAULT_TIME_OUT_MS;
1271     }
1272 
1273     if (!s->expired_scan_cycle) {
1274         /* Set default value to 3000 MS */
1275         s->expired_scan_cycle = REGULAR_PACKET_CHECK_MS;
1276     }
1277 
1278     if (!max_queue_size) {
1279         /* Set default queue size to 1024 */
1280         max_queue_size = MAX_QUEUE_SIZE;
1281     }
1282 
1283     if (find_and_check_chardev(&chr, s->pri_indev, errp) ||
1284         !qemu_chr_fe_init(&s->chr_pri_in, chr, errp)) {
1285         return;
1286     }
1287 
1288     if (find_and_check_chardev(&chr, s->sec_indev, errp) ||
1289         !qemu_chr_fe_init(&s->chr_sec_in, chr, errp)) {
1290         return;
1291     }
1292 
1293     if (find_and_check_chardev(&chr, s->outdev, errp) ||
1294         !qemu_chr_fe_init(&s->chr_out, chr, errp)) {
1295         return;
1296     }
1297 
1298     net_socket_rs_init(&s->pri_rs, compare_pri_rs_finalize, s->vnet_hdr);
1299     net_socket_rs_init(&s->sec_rs, compare_sec_rs_finalize, s->vnet_hdr);
1300 
1301     /* Try to enable remote notify chardev, currently just for Xen COLO */
1302     if (s->notify_dev) {
1303         if (find_and_check_chardev(&chr, s->notify_dev, errp) ||
1304             !qemu_chr_fe_init(&s->chr_notify_dev, chr, errp)) {
1305             return;
1306         }
1307 
1308         net_socket_rs_init(&s->notify_rs, compare_notify_rs_finalize,
1309                            s->vnet_hdr);
1310     }
1311 
1312     s->out_sendco.s = s;
1313     s->out_sendco.chr = &s->chr_out;
1314     s->out_sendco.notify_remote_frame = false;
1315     s->out_sendco.done = true;
1316     g_queue_init(&s->out_sendco.send_list);
1317 
1318     if (s->notify_dev) {
1319         s->notify_sendco.s = s;
1320         s->notify_sendco.chr = &s->chr_notify_dev;
1321         s->notify_sendco.notify_remote_frame = true;
1322         s->notify_sendco.done = true;
1323         g_queue_init(&s->notify_sendco.send_list);
1324     }
1325 
1326     g_queue_init(&s->conn_list);
1327 
1328     s->connection_track_table = g_hash_table_new_full(connection_key_hash,
1329                                                       connection_key_equal,
1330                                                       g_free,
1331                                                       connection_destroy);
1332 
1333     colo_compare_iothread(s);
1334 
1335     qemu_mutex_lock(&colo_compare_mutex);
1336     if (!colo_compare_active) {
1337         qemu_mutex_init(&event_mtx);
1338         qemu_cond_init(&event_complete_cond);
1339         colo_compare_active = true;
1340     }
1341     QTAILQ_INSERT_TAIL(&net_compares, s, next);
1342     qemu_mutex_unlock(&colo_compare_mutex);
1343 
1344     return;
1345 }
1346 
1347 static void colo_flush_packets(void *opaque, void *user_data)
1348 {
1349     CompareState *s = user_data;
1350     Connection *conn = opaque;
1351     Packet *pkt = NULL;
1352 
1353     while (!g_queue_is_empty(&conn->primary_list)) {
1354         pkt = g_queue_pop_head(&conn->primary_list);
1355         compare_chr_send(s,
1356                          pkt->data,
1357                          pkt->size,
1358                          pkt->vnet_hdr_len,
1359                          false,
1360                          true);
1361         packet_destroy_partial(pkt, NULL);
1362     }
1363     while (!g_queue_is_empty(&conn->secondary_list)) {
1364         pkt = g_queue_pop_head(&conn->secondary_list);
1365         packet_destroy(pkt, NULL);
1366     }
1367 }
1368 
1369 static void colo_compare_class_init(ObjectClass *oc, void *data)
1370 {
1371     UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);
1372 
1373     ucc->complete = colo_compare_complete;
1374 }
1375 
1376 static void colo_compare_init(Object *obj)
1377 {
1378     CompareState *s = COLO_COMPARE(obj);
1379 
1380     object_property_add_str(obj, "primary_in",
1381                             compare_get_pri_indev, compare_set_pri_indev);
1382     object_property_add_str(obj, "secondary_in",
1383                             compare_get_sec_indev, compare_set_sec_indev);
1384     object_property_add_str(obj, "outdev",
1385                             compare_get_outdev, compare_set_outdev);
1386     object_property_add_link(obj, "iothread", TYPE_IOTHREAD,
1387                             (Object **)&s->iothread,
1388                             object_property_allow_set_link,
1389                             OBJ_PROP_LINK_STRONG);
1390     /* This parameter just for Xen COLO */
1391     object_property_add_str(obj, "notify_dev",
1392                             compare_get_notify_dev, compare_set_notify_dev);
1393 
1394     object_property_add(obj, "compare_timeout", "uint64",
1395                         compare_get_timeout,
1396                         compare_set_timeout, NULL, NULL);
1397 
1398     object_property_add(obj, "expired_scan_cycle", "uint32",
1399                         compare_get_expired_scan_cycle,
1400                         compare_set_expired_scan_cycle, NULL, NULL);
1401 
1402     object_property_add(obj, "max_queue_size", "uint32",
1403                         get_max_queue_size,
1404                         set_max_queue_size, NULL, NULL);
1405 
1406     s->vnet_hdr = false;
1407     object_property_add_bool(obj, "vnet_hdr_support", compare_get_vnet_hdr,
1408                              compare_set_vnet_hdr);
1409 }
1410 
1411 static void colo_compare_finalize(Object *obj)
1412 {
1413     CompareState *s = COLO_COMPARE(obj);
1414     CompareState *tmp = NULL;
1415 
1416     qemu_mutex_lock(&colo_compare_mutex);
1417     QTAILQ_FOREACH(tmp, &net_compares, next) {
1418         if (tmp == s) {
1419             QTAILQ_REMOVE(&net_compares, s, next);
1420             break;
1421         }
1422     }
1423     if (QTAILQ_EMPTY(&net_compares)) {
1424         colo_compare_active = false;
1425         qemu_mutex_destroy(&event_mtx);
1426         qemu_cond_destroy(&event_complete_cond);
1427     }
1428     qemu_mutex_unlock(&colo_compare_mutex);
1429 
1430     qemu_chr_fe_deinit(&s->chr_pri_in, false);
1431     qemu_chr_fe_deinit(&s->chr_sec_in, false);
1432     qemu_chr_fe_deinit(&s->chr_out, false);
1433     if (s->notify_dev) {
1434         qemu_chr_fe_deinit(&s->chr_notify_dev, false);
1435     }
1436 
1437     colo_compare_timer_del(s);
1438 
1439     qemu_bh_delete(s->event_bh);
1440 
1441     AioContext *ctx = iothread_get_aio_context(s->iothread);
1442     aio_context_acquire(ctx);
1443     AIO_WAIT_WHILE(ctx, !s->out_sendco.done);
1444     if (s->notify_dev) {
1445         AIO_WAIT_WHILE(ctx, !s->notify_sendco.done);
1446     }
1447     aio_context_release(ctx);
1448 
1449     /* Release all unhandled packets after compare thead exited */
1450     g_queue_foreach(&s->conn_list, colo_flush_packets, s);
1451     AIO_WAIT_WHILE(NULL, !s->out_sendco.done);
1452 
1453     g_queue_clear(&s->conn_list);
1454     g_queue_clear(&s->out_sendco.send_list);
1455     if (s->notify_dev) {
1456         g_queue_clear(&s->notify_sendco.send_list);
1457     }
1458 
1459     if (s->connection_track_table) {
1460         g_hash_table_destroy(s->connection_track_table);
1461     }
1462 
1463     object_unref(OBJECT(s->iothread));
1464 
1465     g_free(s->pri_indev);
1466     g_free(s->sec_indev);
1467     g_free(s->outdev);
1468     g_free(s->notify_dev);
1469 }
1470 
1471 static void __attribute__((__constructor__)) colo_compare_init_globals(void)
1472 {
1473     colo_compare_active = false;
1474     qemu_mutex_init(&colo_compare_mutex);
1475 }
1476 
1477 static const TypeInfo colo_compare_info = {
1478     .name = TYPE_COLO_COMPARE,
1479     .parent = TYPE_OBJECT,
1480     .instance_size = sizeof(CompareState),
1481     .instance_init = colo_compare_init,
1482     .instance_finalize = colo_compare_finalize,
1483     .class_size = sizeof(CompareClass),
1484     .class_init = colo_compare_class_init,
1485     .interfaces = (InterfaceInfo[]) {
1486         { TYPE_USER_CREATABLE },
1487         { }
1488     }
1489 };
1490 
1491 static void register_types(void)
1492 {
1493     type_register_static(&colo_compare_info);
1494 }
1495 
1496 type_init(register_types);
1497