xref: /openbmc/qemu/net/colo-compare.c (revision 43709a0c)
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 1000
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, packet_len);
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     /* Need to consider ACK will bigger than uint32_t MAX */
213     *max_ack = pkt->tcp_ack - *max_ack > 0 ? pkt->tcp_ack : *max_ack;
214     pkt->header_size = pkt->transport_header - (uint8_t *)pkt->data
215                        + (tcphd->th_off << 2);
216     pkt->payload_size = pkt->size - pkt->header_size;
217     pkt->seq_end = pkt->tcp_seq + pkt->payload_size;
218     pkt->flags = tcphd->th_flags;
219 }
220 
221 /*
222  * Return 1 on success, if return 0 means the
223  * packet will be dropped
224  */
225 static int colo_insert_packet(GQueue *queue, Packet *pkt, uint32_t *max_ack)
226 {
227     if (g_queue_get_length(queue) <= max_queue_size) {
228         if (pkt->ip->ip_p == IPPROTO_TCP) {
229             fill_pkt_tcp_info(pkt, max_ack);
230             g_queue_insert_sorted(queue,
231                                   pkt,
232                                   (GCompareDataFunc)seq_sorter,
233                                   NULL);
234         } else {
235             g_queue_push_tail(queue, pkt);
236         }
237         return 1;
238     }
239     return 0;
240 }
241 
242 /*
243  * Return 0 on success, if return -1 means the pkt
244  * is unsupported(arp and ipv6) and will be sent later
245  */
246 static int packet_enqueue(CompareState *s, int mode, Connection **con)
247 {
248     ConnectionKey key;
249     Packet *pkt = NULL;
250     Connection *conn;
251     int ret;
252 
253     if (mode == PRIMARY_IN) {
254         pkt = packet_new(s->pri_rs.buf,
255                          s->pri_rs.packet_len,
256                          s->pri_rs.vnet_hdr_len);
257     } else {
258         pkt = packet_new(s->sec_rs.buf,
259                          s->sec_rs.packet_len,
260                          s->sec_rs.vnet_hdr_len);
261     }
262 
263     if (parse_packet_early(pkt)) {
264         packet_destroy(pkt, NULL);
265         pkt = NULL;
266         return -1;
267     }
268     fill_connection_key(pkt, &key, false);
269 
270     conn = connection_get(s->connection_track_table,
271                           &key,
272                           &s->conn_list);
273 
274     if (!conn->processing) {
275         g_queue_push_tail(&s->conn_list, conn);
276         conn->processing = true;
277     }
278 
279     if (mode == PRIMARY_IN) {
280         ret = colo_insert_packet(&conn->primary_list, pkt, &conn->pack);
281     } else {
282         ret = colo_insert_packet(&conn->secondary_list, pkt, &conn->sack);
283     }
284 
285     if (!ret) {
286         trace_colo_compare_drop_packet(colo_mode[mode],
287             "queue size too big, drop packet");
288         packet_destroy(pkt, NULL);
289         pkt = NULL;
290     }
291 
292     *con = conn;
293 
294     return 0;
295 }
296 
297 static inline bool after(uint32_t seq1, uint32_t seq2)
298 {
299         return (int32_t)(seq1 - seq2) > 0;
300 }
301 
302 static void colo_release_primary_pkt(CompareState *s, Packet *pkt)
303 {
304     int ret;
305     ret = compare_chr_send(s,
306                            pkt->data,
307                            pkt->size,
308                            pkt->vnet_hdr_len,
309                            false,
310                            true);
311     if (ret < 0) {
312         error_report("colo send primary packet failed");
313     }
314     trace_colo_compare_main("packet same and release packet");
315     packet_destroy_partial(pkt, NULL);
316 }
317 
318 /*
319  * The IP packets sent by primary and secondary
320  * will be compared in here
321  * TODO support ip fragment, Out-Of-Order
322  * return:    0  means packet same
323  *            > 0 || < 0 means packet different
324  */
325 static int colo_compare_packet_payload(Packet *ppkt,
326                                        Packet *spkt,
327                                        uint16_t poffset,
328                                        uint16_t soffset,
329                                        uint16_t len)
330 
331 {
332     if (trace_event_get_state_backends(TRACE_COLO_COMPARE_IP_INFO)) {
333         char pri_ip_src[20], pri_ip_dst[20], sec_ip_src[20], sec_ip_dst[20];
334 
335         strcpy(pri_ip_src, inet_ntoa(ppkt->ip->ip_src));
336         strcpy(pri_ip_dst, inet_ntoa(ppkt->ip->ip_dst));
337         strcpy(sec_ip_src, inet_ntoa(spkt->ip->ip_src));
338         strcpy(sec_ip_dst, inet_ntoa(spkt->ip->ip_dst));
339 
340         trace_colo_compare_ip_info(ppkt->size, pri_ip_src,
341                                    pri_ip_dst, spkt->size,
342                                    sec_ip_src, sec_ip_dst);
343     }
344 
345     return memcmp(ppkt->data + poffset, spkt->data + soffset, len);
346 }
347 
348 /*
349  * return true means that the payload is consist and
350  * need to make the next comparison, false means do
351  * the checkpoint
352 */
353 static bool colo_mark_tcp_pkt(Packet *ppkt, Packet *spkt,
354                               int8_t *mark, uint32_t max_ack)
355 {
356     *mark = 0;
357 
358     if (ppkt->tcp_seq == spkt->tcp_seq && ppkt->seq_end == spkt->seq_end) {
359         if (!colo_compare_packet_payload(ppkt, spkt,
360                                         ppkt->header_size, spkt->header_size,
361                                         ppkt->payload_size)) {
362             *mark = COLO_COMPARE_FREE_SECONDARY | COLO_COMPARE_FREE_PRIMARY;
363             return true;
364         }
365     }
366 
367     /* one part of secondary packet payload still need to be compared */
368     if (!after(ppkt->seq_end, spkt->seq_end)) {
369         if (!colo_compare_packet_payload(ppkt, spkt,
370                                         ppkt->header_size + ppkt->offset,
371                                         spkt->header_size + spkt->offset,
372                                         ppkt->payload_size - ppkt->offset)) {
373             if (!after(ppkt->tcp_ack, max_ack)) {
374                 *mark = COLO_COMPARE_FREE_PRIMARY;
375                 spkt->offset += ppkt->payload_size - ppkt->offset;
376                 return true;
377             } else {
378                 /* secondary guest hasn't ack the data, don't send
379                  * out this packet
380                  */
381                 return false;
382             }
383         }
384     } else {
385         /* primary packet is longer than secondary packet, compare
386          * the same part and mark the primary packet offset
387          */
388         if (!colo_compare_packet_payload(ppkt, spkt,
389                                         ppkt->header_size + ppkt->offset,
390                                         spkt->header_size + spkt->offset,
391                                         spkt->payload_size - spkt->offset)) {
392             *mark = COLO_COMPARE_FREE_SECONDARY;
393             ppkt->offset += spkt->payload_size - spkt->offset;
394             return true;
395         }
396     }
397 
398     return false;
399 }
400 
401 static void colo_compare_tcp(CompareState *s, Connection *conn)
402 {
403     Packet *ppkt = NULL, *spkt = NULL;
404     int8_t mark;
405 
406     /*
407      * If ppkt and spkt have the same payload, but ppkt's ACK
408      * is greater than spkt's ACK, in this case we can not
409      * send the ppkt because it will cause the secondary guest
410      * to miss sending some data in the next. Therefore, we
411      * record the maximum ACK in the current queue at both
412      * primary side and secondary side. Only when the ack is
413      * less than the smaller of the two maximum ack, then we
414      * can ensure that the packet's payload is acknowledged by
415      * primary and secondary.
416     */
417     uint32_t min_ack = conn->pack - conn->sack > 0 ?
418                        conn->sack : conn->pack;
419 
420 pri:
421     if (g_queue_is_empty(&conn->primary_list)) {
422         return;
423     }
424     ppkt = g_queue_pop_head(&conn->primary_list);
425 sec:
426     if (g_queue_is_empty(&conn->secondary_list)) {
427         g_queue_push_head(&conn->primary_list, ppkt);
428         return;
429     }
430     spkt = g_queue_pop_head(&conn->secondary_list);
431 
432     if (ppkt->tcp_seq == ppkt->seq_end) {
433         colo_release_primary_pkt(s, ppkt);
434         ppkt = NULL;
435     }
436 
437     if (ppkt && conn->compare_seq && !after(ppkt->seq_end, conn->compare_seq)) {
438         trace_colo_compare_main("pri: this packet has compared");
439         colo_release_primary_pkt(s, ppkt);
440         ppkt = NULL;
441     }
442 
443     if (spkt->tcp_seq == spkt->seq_end) {
444         packet_destroy(spkt, NULL);
445         if (!ppkt) {
446             goto pri;
447         } else {
448             goto sec;
449         }
450     } else {
451         if (conn->compare_seq && !after(spkt->seq_end, conn->compare_seq)) {
452             trace_colo_compare_main("sec: this packet has compared");
453             packet_destroy(spkt, NULL);
454             if (!ppkt) {
455                 goto pri;
456             } else {
457                 goto sec;
458             }
459         }
460         if (!ppkt) {
461             g_queue_push_head(&conn->secondary_list, spkt);
462             goto pri;
463         }
464     }
465 
466     if (colo_mark_tcp_pkt(ppkt, spkt, &mark, min_ack)) {
467         trace_colo_compare_tcp_info("pri",
468                                     ppkt->tcp_seq, ppkt->tcp_ack,
469                                     ppkt->header_size, ppkt->payload_size,
470                                     ppkt->offset, ppkt->flags);
471 
472         trace_colo_compare_tcp_info("sec",
473                                     spkt->tcp_seq, spkt->tcp_ack,
474                                     spkt->header_size, spkt->payload_size,
475                                     spkt->offset, spkt->flags);
476 
477         if (mark == COLO_COMPARE_FREE_PRIMARY) {
478             conn->compare_seq = ppkt->seq_end;
479             colo_release_primary_pkt(s, ppkt);
480             g_queue_push_head(&conn->secondary_list, spkt);
481             goto pri;
482         } else if (mark == COLO_COMPARE_FREE_SECONDARY) {
483             conn->compare_seq = spkt->seq_end;
484             packet_destroy(spkt, NULL);
485             goto sec;
486         } else if (mark == (COLO_COMPARE_FREE_PRIMARY | COLO_COMPARE_FREE_SECONDARY)) {
487             conn->compare_seq = ppkt->seq_end;
488             colo_release_primary_pkt(s, ppkt);
489             packet_destroy(spkt, NULL);
490             goto pri;
491         }
492     } else {
493         g_queue_push_head(&conn->primary_list, ppkt);
494         g_queue_push_head(&conn->secondary_list, spkt);
495 
496 #ifdef DEBUG_COLO_PACKETS
497         qemu_hexdump(stderr, "colo-compare ppkt", ppkt->data, ppkt->size);
498         qemu_hexdump(stderr, "colo-compare spkt", spkt->data, spkt->size);
499 #endif
500 
501         colo_compare_inconsistency_notify(s);
502     }
503 }
504 
505 
506 /*
507  * Called from the compare thread on the primary
508  * for compare udp packet
509  */
510 static int colo_packet_compare_udp(Packet *spkt, Packet *ppkt)
511 {
512     uint16_t network_header_length = ppkt->ip->ip_hl << 2;
513     uint16_t offset = network_header_length + ETH_HLEN + ppkt->vnet_hdr_len;
514 
515     trace_colo_compare_main("compare udp");
516 
517     /*
518      * Because of ppkt and spkt are both in the same connection,
519      * The ppkt's src ip, dst ip, src port, dst port, ip_proto all are
520      * same with spkt. In addition, IP header's Identification is a random
521      * field, we can handle it in IP fragmentation function later.
522      * COLO just concern the response net packet payload from primary guest
523      * and secondary guest are same or not, So we ignored all IP header include
524      * other field like TOS,TTL,IP Checksum. we only need to compare
525      * the ip payload here.
526      */
527     if (ppkt->size != spkt->size) {
528         trace_colo_compare_main("UDP: payload size of packets are different");
529         return -1;
530     }
531     if (colo_compare_packet_payload(ppkt, spkt, offset, offset,
532                                     ppkt->size - offset)) {
533         trace_colo_compare_udp_miscompare("primary pkt size", ppkt->size);
534         trace_colo_compare_udp_miscompare("Secondary pkt size", spkt->size);
535 #ifdef DEBUG_COLO_PACKETS
536         qemu_hexdump(stderr, "colo-compare pri pkt", ppkt->data, ppkt->size);
537         qemu_hexdump(stderr, "colo-compare sec pkt", spkt->data, spkt->size);
538 #endif
539         return -1;
540     } else {
541         return 0;
542     }
543 }
544 
545 /*
546  * Called from the compare thread on the primary
547  * for compare icmp packet
548  */
549 static int colo_packet_compare_icmp(Packet *spkt, Packet *ppkt)
550 {
551     uint16_t network_header_length = ppkt->ip->ip_hl << 2;
552     uint16_t offset = network_header_length + ETH_HLEN + ppkt->vnet_hdr_len;
553 
554     trace_colo_compare_main("compare icmp");
555 
556     /*
557      * Because of ppkt and spkt are both in the same connection,
558      * The ppkt's src ip, dst ip, src port, dst port, ip_proto all are
559      * same with spkt. In addition, IP header's Identification is a random
560      * field, we can handle it in IP fragmentation function later.
561      * COLO just concern the response net packet payload from primary guest
562      * and secondary guest are same or not, So we ignored all IP header include
563      * other field like TOS,TTL,IP Checksum. we only need to compare
564      * the ip payload here.
565      */
566     if (ppkt->size != spkt->size) {
567         trace_colo_compare_main("ICMP: payload size of packets are different");
568         return -1;
569     }
570     if (colo_compare_packet_payload(ppkt, spkt, offset, offset,
571                                     ppkt->size - offset)) {
572         trace_colo_compare_icmp_miscompare("primary pkt size",
573                                            ppkt->size);
574         trace_colo_compare_icmp_miscompare("Secondary pkt size",
575                                            spkt->size);
576 #ifdef DEBUG_COLO_PACKETS
577         qemu_hexdump(stderr, "colo-compare pri pkt", ppkt->data, ppkt->size);
578         qemu_hexdump(stderr, "colo-compare sec pkt", spkt->data, spkt->size);
579 #endif
580         return -1;
581     } else {
582         return 0;
583     }
584 }
585 
586 /*
587  * Called from the compare thread on the primary
588  * for compare other packet
589  */
590 static int colo_packet_compare_other(Packet *spkt, Packet *ppkt)
591 {
592     uint16_t offset = ppkt->vnet_hdr_len;
593 
594     trace_colo_compare_main("compare other");
595     if (ppkt->size != spkt->size) {
596         trace_colo_compare_main("Other: payload size of packets are different");
597         return -1;
598     }
599     return colo_compare_packet_payload(ppkt, spkt, offset, offset,
600                                        ppkt->size - offset);
601 }
602 
603 static int colo_old_packet_check_one(Packet *pkt, int64_t *check_time)
604 {
605     int64_t now = qemu_clock_get_ms(QEMU_CLOCK_HOST);
606 
607     if ((now - pkt->creation_ms) > (*check_time)) {
608         trace_colo_old_packet_check_found(pkt->creation_ms);
609         return 0;
610     } else {
611         return 1;
612     }
613 }
614 
615 void colo_compare_register_notifier(Notifier *notify)
616 {
617     notifier_list_add(&colo_compare_notifiers, notify);
618 }
619 
620 void colo_compare_unregister_notifier(Notifier *notify)
621 {
622     notifier_remove(notify);
623 }
624 
625 static int colo_old_packet_check_one_conn(Connection *conn,
626                                           CompareState *s)
627 {
628     if (!g_queue_is_empty(&conn->primary_list)) {
629         if (g_queue_find_custom(&conn->primary_list,
630                                 &s->compare_timeout,
631                                 (GCompareFunc)colo_old_packet_check_one))
632             goto out;
633     }
634 
635     if (!g_queue_is_empty(&conn->secondary_list)) {
636         if (g_queue_find_custom(&conn->secondary_list,
637                                 &s->compare_timeout,
638                                 (GCompareFunc)colo_old_packet_check_one))
639             goto out;
640     }
641 
642     return 1;
643 
644 out:
645     /* Do checkpoint will flush old packet */
646     colo_compare_inconsistency_notify(s);
647     return 0;
648 }
649 
650 /*
651  * Look for old packets that the secondary hasn't matched,
652  * if we have some then we have to checkpoint to wake
653  * the secondary up.
654  */
655 static void colo_old_packet_check(void *opaque)
656 {
657     CompareState *s = opaque;
658 
659     /*
660      * If we find one old packet, stop finding job and notify
661      * COLO frame do checkpoint.
662      */
663     g_queue_find_custom(&s->conn_list, s,
664                         (GCompareFunc)colo_old_packet_check_one_conn);
665 }
666 
667 static void colo_compare_packet(CompareState *s, Connection *conn,
668                                 int (*HandlePacket)(Packet *spkt,
669                                 Packet *ppkt))
670 {
671     Packet *pkt = NULL;
672     GList *result = NULL;
673 
674     while (!g_queue_is_empty(&conn->primary_list) &&
675            !g_queue_is_empty(&conn->secondary_list)) {
676         pkt = g_queue_pop_head(&conn->primary_list);
677         result = g_queue_find_custom(&conn->secondary_list,
678                  pkt, (GCompareFunc)HandlePacket);
679 
680         if (result) {
681             colo_release_primary_pkt(s, pkt);
682             packet_destroy(result->data, NULL);
683             g_queue_delete_link(&conn->secondary_list, result);
684         } else {
685             /*
686              * If one packet arrive late, the secondary_list or
687              * primary_list will be empty, so we can't compare it
688              * until next comparison. If the packets in the list are
689              * timeout, it will trigger a checkpoint request.
690              */
691             trace_colo_compare_main("packet different");
692             g_queue_push_head(&conn->primary_list, pkt);
693 
694             colo_compare_inconsistency_notify(s);
695             break;
696         }
697     }
698 }
699 
700 /*
701  * Called from the compare thread on the primary
702  * for compare packet with secondary list of the
703  * specified connection when a new packet was
704  * queued to it.
705  */
706 static void colo_compare_connection(void *opaque, void *user_data)
707 {
708     CompareState *s = user_data;
709     Connection *conn = opaque;
710 
711     switch (conn->ip_proto) {
712     case IPPROTO_TCP:
713         colo_compare_tcp(s, conn);
714         break;
715     case IPPROTO_UDP:
716         colo_compare_packet(s, conn, colo_packet_compare_udp);
717         break;
718     case IPPROTO_ICMP:
719         colo_compare_packet(s, conn, colo_packet_compare_icmp);
720         break;
721     default:
722         colo_compare_packet(s, conn, colo_packet_compare_other);
723         break;
724     }
725 }
726 
727 static void coroutine_fn _compare_chr_send(void *opaque)
728 {
729     SendCo *sendco = opaque;
730     CompareState *s = sendco->s;
731     int ret = 0;
732 
733     while (!g_queue_is_empty(&sendco->send_list)) {
734         SendEntry *entry = g_queue_pop_tail(&sendco->send_list);
735         uint32_t len = htonl(entry->size);
736 
737         ret = qemu_chr_fe_write_all(sendco->chr, (uint8_t *)&len, sizeof(len));
738 
739         if (ret != sizeof(len)) {
740             g_free(entry->buf);
741             g_slice_free(SendEntry, entry);
742             goto err;
743         }
744 
745         if (!sendco->notify_remote_frame && s->vnet_hdr) {
746             /*
747              * We send vnet header len make other module(like filter-redirector)
748              * know how to parse net packet correctly.
749              */
750             len = htonl(entry->vnet_hdr_len);
751 
752             ret = qemu_chr_fe_write_all(sendco->chr,
753                                         (uint8_t *)&len,
754                                         sizeof(len));
755 
756             if (ret != sizeof(len)) {
757                 g_free(entry->buf);
758                 g_slice_free(SendEntry, entry);
759                 goto err;
760             }
761         }
762 
763         ret = qemu_chr_fe_write_all(sendco->chr,
764                                     (uint8_t *)entry->buf,
765                                     entry->size);
766 
767         if (ret != entry->size) {
768             g_free(entry->buf);
769             g_slice_free(SendEntry, entry);
770             goto err;
771         }
772 
773         g_free(entry->buf);
774         g_slice_free(SendEntry, entry);
775     }
776 
777     sendco->ret = 0;
778     goto out;
779 
780 err:
781     while (!g_queue_is_empty(&sendco->send_list)) {
782         SendEntry *entry = g_queue_pop_tail(&sendco->send_list);
783         g_free(entry->buf);
784         g_slice_free(SendEntry, entry);
785     }
786     sendco->ret = ret < 0 ? ret : -EIO;
787 out:
788     sendco->co = NULL;
789     sendco->done = true;
790     aio_wait_kick();
791 }
792 
793 static int compare_chr_send(CompareState *s,
794                             uint8_t *buf,
795                             uint32_t size,
796                             uint32_t vnet_hdr_len,
797                             bool notify_remote_frame,
798                             bool zero_copy)
799 {
800     SendCo *sendco;
801     SendEntry *entry;
802 
803     if (notify_remote_frame) {
804         sendco = &s->notify_sendco;
805     } else {
806         sendco = &s->out_sendco;
807     }
808 
809     if (!size) {
810         return -1;
811     }
812 
813     entry = g_slice_new(SendEntry);
814     entry->size = size;
815     entry->vnet_hdr_len = vnet_hdr_len;
816     if (zero_copy) {
817         entry->buf = buf;
818     } else {
819         entry->buf = g_malloc(size);
820         memcpy(entry->buf, buf, size);
821     }
822     g_queue_push_head(&sendco->send_list, entry);
823 
824     if (sendco->done) {
825         sendco->co = qemu_coroutine_create(_compare_chr_send, sendco);
826         sendco->done = false;
827         qemu_coroutine_enter(sendco->co);
828         if (sendco->done) {
829             /* report early errors */
830             return sendco->ret;
831         }
832     }
833 
834     /* assume success */
835     return 0;
836 }
837 
838 static int compare_chr_can_read(void *opaque)
839 {
840     return COMPARE_READ_LEN_MAX;
841 }
842 
843 /*
844  * Called from the main thread on the primary for packets
845  * arriving over the socket from the primary.
846  */
847 static void compare_pri_chr_in(void *opaque, const uint8_t *buf, int size)
848 {
849     CompareState *s = COLO_COMPARE(opaque);
850     int ret;
851 
852     ret = net_fill_rstate(&s->pri_rs, buf, size);
853     if (ret == -1) {
854         qemu_chr_fe_set_handlers(&s->chr_pri_in, NULL, NULL, NULL, NULL,
855                                  NULL, NULL, true);
856         error_report("colo-compare primary_in error");
857     }
858 }
859 
860 /*
861  * Called from the main thread on the primary for packets
862  * arriving over the socket from the secondary.
863  */
864 static void compare_sec_chr_in(void *opaque, const uint8_t *buf, int size)
865 {
866     CompareState *s = COLO_COMPARE(opaque);
867     int ret;
868 
869     ret = net_fill_rstate(&s->sec_rs, buf, size);
870     if (ret == -1) {
871         qemu_chr_fe_set_handlers(&s->chr_sec_in, NULL, NULL, NULL, NULL,
872                                  NULL, NULL, true);
873         error_report("colo-compare secondary_in error");
874     }
875 }
876 
877 static void compare_notify_chr(void *opaque, const uint8_t *buf, int size)
878 {
879     CompareState *s = COLO_COMPARE(opaque);
880     int ret;
881 
882     ret = net_fill_rstate(&s->notify_rs, buf, size);
883     if (ret == -1) {
884         qemu_chr_fe_set_handlers(&s->chr_notify_dev, NULL, NULL, NULL, NULL,
885                                  NULL, NULL, true);
886         error_report("colo-compare notify_dev error");
887     }
888 }
889 
890 /*
891  * Check old packet regularly so it can watch for any packets
892  * that the secondary hasn't produced equivalents of.
893  */
894 static void check_old_packet_regular(void *opaque)
895 {
896     CompareState *s = opaque;
897 
898     /* if have old packet we will notify checkpoint */
899     colo_old_packet_check(s);
900     timer_mod(s->packet_check_timer, qemu_clock_get_ms(QEMU_CLOCK_HOST) +
901               s->expired_scan_cycle);
902 }
903 
904 /* Public API, Used for COLO frame to notify compare event */
905 void colo_notify_compares_event(void *opaque, int event, Error **errp)
906 {
907     CompareState *s;
908     qemu_mutex_lock(&colo_compare_mutex);
909 
910     if (!colo_compare_active) {
911         qemu_mutex_unlock(&colo_compare_mutex);
912         return;
913     }
914 
915     qemu_mutex_lock(&event_mtx);
916     QTAILQ_FOREACH(s, &net_compares, next) {
917         s->event = event;
918         qemu_bh_schedule(s->event_bh);
919         event_unhandled_count++;
920     }
921     /* Wait all compare threads to finish handling this event */
922     while (event_unhandled_count > 0) {
923         qemu_cond_wait(&event_complete_cond, &event_mtx);
924     }
925 
926     qemu_mutex_unlock(&event_mtx);
927     qemu_mutex_unlock(&colo_compare_mutex);
928 }
929 
930 static void colo_compare_timer_init(CompareState *s)
931 {
932     AioContext *ctx = iothread_get_aio_context(s->iothread);
933 
934     s->packet_check_timer = aio_timer_new(ctx, QEMU_CLOCK_HOST,
935                                 SCALE_MS, check_old_packet_regular,
936                                 s);
937     timer_mod(s->packet_check_timer, qemu_clock_get_ms(QEMU_CLOCK_HOST) +
938               s->expired_scan_cycle);
939 }
940 
941 static void colo_compare_timer_del(CompareState *s)
942 {
943     if (s->packet_check_timer) {
944         timer_free(s->packet_check_timer);
945         s->packet_check_timer = NULL;
946     }
947  }
948 
949 static void colo_flush_packets(void *opaque, void *user_data);
950 
951 static void colo_compare_handle_event(void *opaque)
952 {
953     CompareState *s = opaque;
954 
955     switch (s->event) {
956     case COLO_EVENT_CHECKPOINT:
957         g_queue_foreach(&s->conn_list, colo_flush_packets, s);
958         break;
959     case COLO_EVENT_FAILOVER:
960         break;
961     default:
962         break;
963     }
964 
965     qemu_mutex_lock(&event_mtx);
966     assert(event_unhandled_count > 0);
967     event_unhandled_count--;
968     qemu_cond_broadcast(&event_complete_cond);
969     qemu_mutex_unlock(&event_mtx);
970 }
971 
972 static void colo_compare_iothread(CompareState *s)
973 {
974     AioContext *ctx = iothread_get_aio_context(s->iothread);
975     object_ref(OBJECT(s->iothread));
976     s->worker_context = iothread_get_g_main_context(s->iothread);
977 
978     qemu_chr_fe_set_handlers(&s->chr_pri_in, compare_chr_can_read,
979                              compare_pri_chr_in, NULL, NULL,
980                              s, s->worker_context, true);
981     qemu_chr_fe_set_handlers(&s->chr_sec_in, compare_chr_can_read,
982                              compare_sec_chr_in, NULL, NULL,
983                              s, s->worker_context, true);
984     if (s->notify_dev) {
985         qemu_chr_fe_set_handlers(&s->chr_notify_dev, compare_chr_can_read,
986                                  compare_notify_chr, NULL, NULL,
987                                  s, s->worker_context, true);
988     }
989 
990     colo_compare_timer_init(s);
991     s->event_bh = aio_bh_new(ctx, colo_compare_handle_event, s);
992 }
993 
994 static char *compare_get_pri_indev(Object *obj, Error **errp)
995 {
996     CompareState *s = COLO_COMPARE(obj);
997 
998     return g_strdup(s->pri_indev);
999 }
1000 
1001 static void compare_set_pri_indev(Object *obj, const char *value, Error **errp)
1002 {
1003     CompareState *s = COLO_COMPARE(obj);
1004 
1005     g_free(s->pri_indev);
1006     s->pri_indev = g_strdup(value);
1007 }
1008 
1009 static char *compare_get_sec_indev(Object *obj, Error **errp)
1010 {
1011     CompareState *s = COLO_COMPARE(obj);
1012 
1013     return g_strdup(s->sec_indev);
1014 }
1015 
1016 static void compare_set_sec_indev(Object *obj, const char *value, Error **errp)
1017 {
1018     CompareState *s = COLO_COMPARE(obj);
1019 
1020     g_free(s->sec_indev);
1021     s->sec_indev = g_strdup(value);
1022 }
1023 
1024 static char *compare_get_outdev(Object *obj, Error **errp)
1025 {
1026     CompareState *s = COLO_COMPARE(obj);
1027 
1028     return g_strdup(s->outdev);
1029 }
1030 
1031 static void compare_set_outdev(Object *obj, const char *value, Error **errp)
1032 {
1033     CompareState *s = COLO_COMPARE(obj);
1034 
1035     g_free(s->outdev);
1036     s->outdev = g_strdup(value);
1037 }
1038 
1039 static bool compare_get_vnet_hdr(Object *obj, Error **errp)
1040 {
1041     CompareState *s = COLO_COMPARE(obj);
1042 
1043     return s->vnet_hdr;
1044 }
1045 
1046 static void compare_set_vnet_hdr(Object *obj,
1047                                  bool value,
1048                                  Error **errp)
1049 {
1050     CompareState *s = COLO_COMPARE(obj);
1051 
1052     s->vnet_hdr = value;
1053 }
1054 
1055 static char *compare_get_notify_dev(Object *obj, Error **errp)
1056 {
1057     CompareState *s = COLO_COMPARE(obj);
1058 
1059     return g_strdup(s->notify_dev);
1060 }
1061 
1062 static void compare_set_notify_dev(Object *obj, const char *value, Error **errp)
1063 {
1064     CompareState *s = COLO_COMPARE(obj);
1065 
1066     g_free(s->notify_dev);
1067     s->notify_dev = g_strdup(value);
1068 }
1069 
1070 static void compare_get_timeout(Object *obj, Visitor *v,
1071                                 const char *name, void *opaque,
1072                                 Error **errp)
1073 {
1074     CompareState *s = COLO_COMPARE(obj);
1075     uint64_t value = s->compare_timeout;
1076 
1077     visit_type_uint64(v, name, &value, errp);
1078 }
1079 
1080 static void compare_set_timeout(Object *obj, Visitor *v,
1081                                 const char *name, void *opaque,
1082                                 Error **errp)
1083 {
1084     CompareState *s = COLO_COMPARE(obj);
1085     uint32_t value;
1086 
1087     if (!visit_type_uint32(v, name, &value, errp)) {
1088         return;
1089     }
1090     if (!value) {
1091         error_setg(errp, "Property '%s.%s' requires a positive value",
1092                    object_get_typename(obj), name);
1093         return;
1094     }
1095     s->compare_timeout = value;
1096 }
1097 
1098 static void compare_get_expired_scan_cycle(Object *obj, Visitor *v,
1099                                            const char *name, void *opaque,
1100                                            Error **errp)
1101 {
1102     CompareState *s = COLO_COMPARE(obj);
1103     uint32_t value = s->expired_scan_cycle;
1104 
1105     visit_type_uint32(v, name, &value, errp);
1106 }
1107 
1108 static void compare_set_expired_scan_cycle(Object *obj, Visitor *v,
1109                                            const char *name, void *opaque,
1110                                            Error **errp)
1111 {
1112     CompareState *s = COLO_COMPARE(obj);
1113     uint32_t value;
1114 
1115     if (!visit_type_uint32(v, name, &value, errp)) {
1116         return;
1117     }
1118     if (!value) {
1119         error_setg(errp, "Property '%s.%s' requires a positive value",
1120                    object_get_typename(obj), name);
1121         return;
1122     }
1123     s->expired_scan_cycle = value;
1124 }
1125 
1126 static void get_max_queue_size(Object *obj, Visitor *v,
1127                                const char *name, void *opaque,
1128                                Error **errp)
1129 {
1130     uint32_t value = max_queue_size;
1131 
1132     visit_type_uint32(v, name, &value, errp);
1133 }
1134 
1135 static void set_max_queue_size(Object *obj, Visitor *v,
1136                                const char *name, void *opaque,
1137                                Error **errp)
1138 {
1139     Error *local_err = NULL;
1140     uint64_t value;
1141 
1142     visit_type_uint64(v, name, &value, &local_err);
1143     if (local_err) {
1144         goto out;
1145     }
1146     if (!value) {
1147         error_setg(&local_err, "Property '%s.%s' requires a positive value",
1148                    object_get_typename(obj), name);
1149         goto out;
1150     }
1151     max_queue_size = value;
1152 
1153 out:
1154     error_propagate(errp, local_err);
1155 }
1156 
1157 static void compare_pri_rs_finalize(SocketReadState *pri_rs)
1158 {
1159     CompareState *s = container_of(pri_rs, CompareState, pri_rs);
1160     Connection *conn = NULL;
1161 
1162     if (packet_enqueue(s, PRIMARY_IN, &conn)) {
1163         trace_colo_compare_main("primary: unsupported packet in");
1164         compare_chr_send(s,
1165                          pri_rs->buf,
1166                          pri_rs->packet_len,
1167                          pri_rs->vnet_hdr_len,
1168                          false,
1169                          false);
1170     } else {
1171         /* compare packet in the specified connection */
1172         colo_compare_connection(conn, s);
1173     }
1174 }
1175 
1176 static void compare_sec_rs_finalize(SocketReadState *sec_rs)
1177 {
1178     CompareState *s = container_of(sec_rs, CompareState, sec_rs);
1179     Connection *conn = NULL;
1180 
1181     if (packet_enqueue(s, SECONDARY_IN, &conn)) {
1182         trace_colo_compare_main("secondary: unsupported packet in");
1183     } else {
1184         /* compare packet in the specified connection */
1185         colo_compare_connection(conn, s);
1186     }
1187 }
1188 
1189 static void compare_notify_rs_finalize(SocketReadState *notify_rs)
1190 {
1191     CompareState *s = container_of(notify_rs, CompareState, notify_rs);
1192 
1193     const char msg[] = "COLO_COMPARE_GET_XEN_INIT";
1194     int ret;
1195 
1196     if (packet_matches_str("COLO_USERSPACE_PROXY_INIT",
1197                            notify_rs->buf,
1198                            notify_rs->packet_len)) {
1199         ret = compare_chr_send(s, (uint8_t *)msg, strlen(msg), 0, true, false);
1200         if (ret < 0) {
1201             error_report("Notify Xen COLO-frame INIT failed");
1202         }
1203     } else if (packet_matches_str("COLO_CHECKPOINT",
1204                                   notify_rs->buf,
1205                                   notify_rs->packet_len)) {
1206         /* colo-compare do checkpoint, flush pri packet and remove sec packet */
1207         g_queue_foreach(&s->conn_list, colo_flush_packets, s);
1208     } else {
1209         error_report("COLO compare got unsupported instruction");
1210     }
1211 }
1212 
1213 /*
1214  * Return 0 is success.
1215  * Return 1 is failed.
1216  */
1217 static int find_and_check_chardev(Chardev **chr,
1218                                   char *chr_name,
1219                                   Error **errp)
1220 {
1221     *chr = qemu_chr_find(chr_name);
1222     if (*chr == NULL) {
1223         error_setg(errp, "Device '%s' not found",
1224                    chr_name);
1225         return 1;
1226     }
1227 
1228     if (!qemu_chr_has_feature(*chr, QEMU_CHAR_FEATURE_RECONNECTABLE)) {
1229         error_setg(errp, "chardev \"%s\" is not reconnectable",
1230                    chr_name);
1231         return 1;
1232     }
1233 
1234     if (!qemu_chr_has_feature(*chr, QEMU_CHAR_FEATURE_GCONTEXT)) {
1235         error_setg(errp, "chardev \"%s\" cannot switch context",
1236                    chr_name);
1237         return 1;
1238     }
1239 
1240     return 0;
1241 }
1242 
1243 /*
1244  * Called from the main thread on the primary
1245  * to setup colo-compare.
1246  */
1247 static void colo_compare_complete(UserCreatable *uc, Error **errp)
1248 {
1249     CompareState *s = COLO_COMPARE(uc);
1250     Chardev *chr;
1251 
1252     if (!s->pri_indev || !s->sec_indev || !s->outdev || !s->iothread) {
1253         error_setg(errp, "colo compare needs 'primary_in' ,"
1254                    "'secondary_in','outdev','iothread' property set");
1255         return;
1256     } else if (!strcmp(s->pri_indev, s->outdev) ||
1257                !strcmp(s->sec_indev, s->outdev) ||
1258                !strcmp(s->pri_indev, s->sec_indev)) {
1259         error_setg(errp, "'indev' and 'outdev' could not be same "
1260                    "for compare module");
1261         return;
1262     }
1263 
1264     if (!s->compare_timeout) {
1265         /* Set default value to 3000 MS */
1266         s->compare_timeout = DEFAULT_TIME_OUT_MS;
1267     }
1268 
1269     if (!s->expired_scan_cycle) {
1270         /* Set default value to 3000 MS */
1271         s->expired_scan_cycle = REGULAR_PACKET_CHECK_MS;
1272     }
1273 
1274     if (!max_queue_size) {
1275         /* Set default queue size to 1024 */
1276         max_queue_size = MAX_QUEUE_SIZE;
1277     }
1278 
1279     if (find_and_check_chardev(&chr, s->pri_indev, errp) ||
1280         !qemu_chr_fe_init(&s->chr_pri_in, chr, errp)) {
1281         return;
1282     }
1283 
1284     if (find_and_check_chardev(&chr, s->sec_indev, errp) ||
1285         !qemu_chr_fe_init(&s->chr_sec_in, chr, errp)) {
1286         return;
1287     }
1288 
1289     if (find_and_check_chardev(&chr, s->outdev, errp) ||
1290         !qemu_chr_fe_init(&s->chr_out, chr, errp)) {
1291         return;
1292     }
1293 
1294     net_socket_rs_init(&s->pri_rs, compare_pri_rs_finalize, s->vnet_hdr);
1295     net_socket_rs_init(&s->sec_rs, compare_sec_rs_finalize, s->vnet_hdr);
1296 
1297     /* Try to enable remote notify chardev, currently just for Xen COLO */
1298     if (s->notify_dev) {
1299         if (find_and_check_chardev(&chr, s->notify_dev, errp) ||
1300             !qemu_chr_fe_init(&s->chr_notify_dev, chr, errp)) {
1301             return;
1302         }
1303 
1304         net_socket_rs_init(&s->notify_rs, compare_notify_rs_finalize,
1305                            s->vnet_hdr);
1306     }
1307 
1308     s->out_sendco.s = s;
1309     s->out_sendco.chr = &s->chr_out;
1310     s->out_sendco.notify_remote_frame = false;
1311     s->out_sendco.done = true;
1312     g_queue_init(&s->out_sendco.send_list);
1313 
1314     if (s->notify_dev) {
1315         s->notify_sendco.s = s;
1316         s->notify_sendco.chr = &s->chr_notify_dev;
1317         s->notify_sendco.notify_remote_frame = true;
1318         s->notify_sendco.done = true;
1319         g_queue_init(&s->notify_sendco.send_list);
1320     }
1321 
1322     g_queue_init(&s->conn_list);
1323 
1324     s->connection_track_table = g_hash_table_new_full(connection_key_hash,
1325                                                       connection_key_equal,
1326                                                       g_free,
1327                                                       connection_destroy);
1328 
1329     colo_compare_iothread(s);
1330 
1331     qemu_mutex_lock(&colo_compare_mutex);
1332     if (!colo_compare_active) {
1333         qemu_mutex_init(&event_mtx);
1334         qemu_cond_init(&event_complete_cond);
1335         colo_compare_active = true;
1336     }
1337     QTAILQ_INSERT_TAIL(&net_compares, s, next);
1338     qemu_mutex_unlock(&colo_compare_mutex);
1339 
1340     return;
1341 }
1342 
1343 static void colo_flush_packets(void *opaque, void *user_data)
1344 {
1345     CompareState *s = user_data;
1346     Connection *conn = opaque;
1347     Packet *pkt = NULL;
1348 
1349     while (!g_queue_is_empty(&conn->primary_list)) {
1350         pkt = g_queue_pop_head(&conn->primary_list);
1351         compare_chr_send(s,
1352                          pkt->data,
1353                          pkt->size,
1354                          pkt->vnet_hdr_len,
1355                          false,
1356                          true);
1357         packet_destroy_partial(pkt, NULL);
1358     }
1359     while (!g_queue_is_empty(&conn->secondary_list)) {
1360         pkt = g_queue_pop_head(&conn->secondary_list);
1361         packet_destroy(pkt, NULL);
1362     }
1363 }
1364 
1365 static void colo_compare_class_init(ObjectClass *oc, void *data)
1366 {
1367     UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);
1368 
1369     ucc->complete = colo_compare_complete;
1370 }
1371 
1372 static void colo_compare_init(Object *obj)
1373 {
1374     CompareState *s = COLO_COMPARE(obj);
1375 
1376     object_property_add_str(obj, "primary_in",
1377                             compare_get_pri_indev, compare_set_pri_indev);
1378     object_property_add_str(obj, "secondary_in",
1379                             compare_get_sec_indev, compare_set_sec_indev);
1380     object_property_add_str(obj, "outdev",
1381                             compare_get_outdev, compare_set_outdev);
1382     object_property_add_link(obj, "iothread", TYPE_IOTHREAD,
1383                             (Object **)&s->iothread,
1384                             object_property_allow_set_link,
1385                             OBJ_PROP_LINK_STRONG);
1386     /* This parameter just for Xen COLO */
1387     object_property_add_str(obj, "notify_dev",
1388                             compare_get_notify_dev, compare_set_notify_dev);
1389 
1390     object_property_add(obj, "compare_timeout", "uint64",
1391                         compare_get_timeout,
1392                         compare_set_timeout, NULL, NULL);
1393 
1394     object_property_add(obj, "expired_scan_cycle", "uint32",
1395                         compare_get_expired_scan_cycle,
1396                         compare_set_expired_scan_cycle, NULL, NULL);
1397 
1398     object_property_add(obj, "max_queue_size", "uint32",
1399                         get_max_queue_size,
1400                         set_max_queue_size, NULL, NULL);
1401 
1402     s->vnet_hdr = false;
1403     object_property_add_bool(obj, "vnet_hdr_support", compare_get_vnet_hdr,
1404                              compare_set_vnet_hdr);
1405 }
1406 
1407 void colo_compare_cleanup(void)
1408 {
1409     CompareState *tmp = NULL;
1410     CompareState *n = NULL;
1411 
1412     QTAILQ_FOREACH_SAFE(tmp, &net_compares, next, n) {
1413         object_unparent(OBJECT(tmp));
1414     }
1415 }
1416 
1417 static void colo_compare_finalize(Object *obj)
1418 {
1419     CompareState *s = COLO_COMPARE(obj);
1420     CompareState *tmp = NULL;
1421 
1422     qemu_mutex_lock(&colo_compare_mutex);
1423     QTAILQ_FOREACH(tmp, &net_compares, next) {
1424         if (tmp == s) {
1425             QTAILQ_REMOVE(&net_compares, s, next);
1426             break;
1427         }
1428     }
1429     if (QTAILQ_EMPTY(&net_compares)) {
1430         colo_compare_active = false;
1431         qemu_mutex_destroy(&event_mtx);
1432         qemu_cond_destroy(&event_complete_cond);
1433     }
1434     qemu_mutex_unlock(&colo_compare_mutex);
1435 
1436     qemu_chr_fe_deinit(&s->chr_pri_in, false);
1437     qemu_chr_fe_deinit(&s->chr_sec_in, false);
1438     qemu_chr_fe_deinit(&s->chr_out, false);
1439     if (s->notify_dev) {
1440         qemu_chr_fe_deinit(&s->chr_notify_dev, false);
1441     }
1442 
1443     colo_compare_timer_del(s);
1444 
1445     qemu_bh_delete(s->event_bh);
1446 
1447     AioContext *ctx = iothread_get_aio_context(s->iothread);
1448     aio_context_acquire(ctx);
1449     AIO_WAIT_WHILE(ctx, !s->out_sendco.done);
1450     if (s->notify_dev) {
1451         AIO_WAIT_WHILE(ctx, !s->notify_sendco.done);
1452     }
1453     aio_context_release(ctx);
1454 
1455     /* Release all unhandled packets after compare thead exited */
1456     g_queue_foreach(&s->conn_list, colo_flush_packets, s);
1457     AIO_WAIT_WHILE(NULL, !s->out_sendco.done);
1458 
1459     g_queue_clear(&s->conn_list);
1460     g_queue_clear(&s->out_sendco.send_list);
1461     if (s->notify_dev) {
1462         g_queue_clear(&s->notify_sendco.send_list);
1463     }
1464 
1465     if (s->connection_track_table) {
1466         g_hash_table_destroy(s->connection_track_table);
1467     }
1468 
1469     object_unref(OBJECT(s->iothread));
1470 
1471     g_free(s->pri_indev);
1472     g_free(s->sec_indev);
1473     g_free(s->outdev);
1474     g_free(s->notify_dev);
1475 }
1476 
1477 static void __attribute__((__constructor__)) colo_compare_init_globals(void)
1478 {
1479     colo_compare_active = false;
1480     qemu_mutex_init(&colo_compare_mutex);
1481 }
1482 
1483 static const TypeInfo colo_compare_info = {
1484     .name = TYPE_COLO_COMPARE,
1485     .parent = TYPE_OBJECT,
1486     .instance_size = sizeof(CompareState),
1487     .instance_init = colo_compare_init,
1488     .instance_finalize = colo_compare_finalize,
1489     .class_size = sizeof(CompareClass),
1490     .class_init = colo_compare_class_init,
1491     .interfaces = (InterfaceInfo[]) {
1492         { TYPE_USER_CREATABLE },
1493         { }
1494     }
1495 };
1496 
1497 static void register_types(void)
1498 {
1499     type_register_static(&colo_compare_info);
1500 }
1501 
1502 type_init(register_types);
1503