xref: /openbmc/qemu/net/colo-compare.c (revision ffe98631)
1 /*
2  * COarse-grain LOck-stepping Virtual Machines for Non-stop Service (COLO)
3  * (a.k.a. Fault Tolerance or Continuous Replication)
4  *
5  * Copyright (c) 2016 HUAWEI TECHNOLOGIES CO., LTD.
6  * Copyright (c) 2016 FUJITSU LIMITED
7  * Copyright (c) 2016 Intel Corporation
8  *
9  * Author: Zhang Chen <zhangchen.fnst@cn.fujitsu.com>
10  *
11  * This work is licensed under the terms of the GNU GPL, version 2 or
12  * later.  See the COPYING file in the top-level directory.
13  */
14 
15 #include "qemu/osdep.h"
16 #include "qemu/error-report.h"
17 #include "trace.h"
18 #include "qapi/error.h"
19 #include "net/net.h"
20 #include "net/eth.h"
21 #include "qom/object_interfaces.h"
22 #include "qemu/iov.h"
23 #include "qom/object.h"
24 #include "net/queue.h"
25 #include "chardev/char-fe.h"
26 #include "qemu/sockets.h"
27 #include "colo.h"
28 #include "sysemu/iothread.h"
29 #include "net/colo-compare.h"
30 #include "migration/colo.h"
31 #include "migration/migration.h"
32 #include "util.h"
33 
34 #include "block/aio-wait.h"
35 #include "qemu/coroutine.h"
36 
37 #define TYPE_COLO_COMPARE "colo-compare"
38 typedef struct CompareState CompareState;
39 DECLARE_INSTANCE_CHECKER(CompareState, COLO_COMPARE,
40                          TYPE_COLO_COMPARE)
41 
42 static QTAILQ_HEAD(, CompareState) net_compares =
43        QTAILQ_HEAD_INITIALIZER(net_compares);
44 
45 static NotifierList colo_compare_notifiers =
46     NOTIFIER_LIST_INITIALIZER(colo_compare_notifiers);
47 
48 #define COMPARE_READ_LEN_MAX NET_BUFSIZE
49 #define MAX_QUEUE_SIZE 1024
50 
51 #define COLO_COMPARE_FREE_PRIMARY     0x01
52 #define COLO_COMPARE_FREE_SECONDARY   0x02
53 
54 #define REGULAR_PACKET_CHECK_MS 1000
55 #define DEFAULT_TIME_OUT_MS 3000
56 
57 /* #define DEBUG_COLO_PACKETS */
58 
59 static QemuMutex colo_compare_mutex;
60 static bool colo_compare_active;
61 static QemuMutex event_mtx;
62 static QemuCond event_complete_cond;
63 static int event_unhandled_count;
64 static uint32_t max_queue_size;
65 
66 /*
67  *  + CompareState ++
68  *  |               |
69  *  +---------------+   +---------------+         +---------------+
70  *  |   conn list   + - >      conn     + ------- >      conn     + -- > ......
71  *  +---------------+   +---------------+         +---------------+
72  *  |               |     |           |             |          |
73  *  +---------------+ +---v----+  +---v----+    +---v----+ +---v----+
74  *                    |primary |  |secondary    |primary | |secondary
75  *                    |packet  |  |packet  +    |packet  | |packet  +
76  *                    +--------+  +--------+    +--------+ +--------+
77  *                        |           |             |          |
78  *                    +---v----+  +---v----+    +---v----+ +---v----+
79  *                    |primary |  |secondary    |primary | |secondary
80  *                    |packet  |  |packet  +    |packet  | |packet  +
81  *                    +--------+  +--------+    +--------+ +--------+
82  *                        |           |             |          |
83  *                    +---v----+  +---v----+    +---v----+ +---v----+
84  *                    |primary |  |secondary    |primary | |secondary
85  *                    |packet  |  |packet  +    |packet  | |packet  +
86  *                    +--------+  +--------+    +--------+ +--------+
87  */
88 
89 typedef struct SendCo {
90     Coroutine *co;
91     struct CompareState *s;
92     CharBackend *chr;
93     GQueue send_list;
94     bool notify_remote_frame;
95     bool done;
96     int ret;
97 } SendCo;
98 
99 typedef struct SendEntry {
100     uint32_t size;
101     uint32_t vnet_hdr_len;
102     uint8_t *buf;
103 } SendEntry;
104 
105 struct CompareState {
106     Object parent;
107 
108     char *pri_indev;
109     char *sec_indev;
110     char *outdev;
111     char *notify_dev;
112     CharBackend chr_pri_in;
113     CharBackend chr_sec_in;
114     CharBackend chr_out;
115     CharBackend chr_notify_dev;
116     SocketReadState pri_rs;
117     SocketReadState sec_rs;
118     SocketReadState notify_rs;
119     SendCo out_sendco;
120     SendCo notify_sendco;
121     bool vnet_hdr;
122     uint64_t compare_timeout;
123     uint32_t expired_scan_cycle;
124 
125     /*
126      * Record the connection that through the NIC
127      * Element type: Connection
128      */
129     GQueue conn_list;
130     /* Record the connection without repetition */
131     GHashTable *connection_track_table;
132 
133     IOThread *iothread;
134     GMainContext *worker_context;
135     QEMUTimer *packet_check_timer;
136 
137     QEMUBH *event_bh;
138     enum colo_event event;
139 
140     QTAILQ_ENTRY(CompareState) next;
141 };
142 
143 typedef struct CompareClass {
144     ObjectClass parent_class;
145 } CompareClass;
146 
147 enum {
148     PRIMARY_IN = 0,
149     SECONDARY_IN,
150 };
151 
152 static const char *colo_mode[] = {
153     [PRIMARY_IN] = "primary",
154     [SECONDARY_IN] = "secondary",
155 };
156 
157 static int compare_chr_send(CompareState *s,
158                             uint8_t *buf,
159                             uint32_t size,
160                             uint32_t vnet_hdr_len,
161                             bool notify_remote_frame,
162                             bool zero_copy);
163 
164 static bool packet_matches_str(const char *str,
165                                const uint8_t *buf,
166                                uint32_t packet_len)
167 {
168     if (packet_len != strlen(str)) {
169         return false;
170     }
171 
172     return !memcmp(str, buf, packet_len);
173 }
174 
175 static void notify_remote_frame(CompareState *s)
176 {
177     char msg[] = "DO_CHECKPOINT";
178     int ret = 0;
179 
180     ret = compare_chr_send(s, (uint8_t *)msg, strlen(msg), 0, true, false);
181     if (ret < 0) {
182         error_report("Notify Xen COLO-frame failed");
183     }
184 }
185 
186 static void colo_compare_inconsistency_notify(CompareState *s)
187 {
188     if (s->notify_dev) {
189         notify_remote_frame(s);
190     } else {
191         notifier_list_notify(&colo_compare_notifiers,
192                              migrate_get_current());
193     }
194 }
195 
196 /* Use restricted to colo_insert_packet() */
197 static gint seq_sorter(Packet *a, Packet *b, gpointer data)
198 {
199     return b->tcp_seq - a->tcp_seq;
200 }
201 
202 static void fill_pkt_tcp_info(void *data, uint32_t *max_ack)
203 {
204     Packet *pkt = data;
205     struct tcp_hdr *tcphd;
206 
207     tcphd = (struct tcp_hdr *)pkt->transport_header;
208 
209     pkt->tcp_seq = ntohl(tcphd->th_seq);
210     pkt->tcp_ack = ntohl(tcphd->th_ack);
211     /* Need to consider ACK will bigger than uint32_t MAX */
212     *max_ack = pkt->tcp_ack - *max_ack > 0 ? pkt->tcp_ack : *max_ack;
213     pkt->header_size = pkt->transport_header - (uint8_t *)pkt->data
214                        + (tcphd->th_off << 2);
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, false);
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 > 0 ?
417                        conn->sack : conn->pack;
418 
419 pri:
420     if (g_queue_is_empty(&conn->primary_list)) {
421         return;
422     }
423     ppkt = g_queue_pop_tail(&conn->primary_list);
424 sec:
425     if (g_queue_is_empty(&conn->secondary_list)) {
426         g_queue_push_tail(&conn->primary_list, ppkt);
427         return;
428     }
429     spkt = g_queue_pop_tail(&conn->secondary_list);
430 
431     if (ppkt->tcp_seq == ppkt->seq_end) {
432         colo_release_primary_pkt(s, ppkt);
433         ppkt = NULL;
434     }
435 
436     if (ppkt && conn->compare_seq && !after(ppkt->seq_end, conn->compare_seq)) {
437         trace_colo_compare_main("pri: this packet has compared");
438         colo_release_primary_pkt(s, ppkt);
439         ppkt = NULL;
440     }
441 
442     if (spkt->tcp_seq == spkt->seq_end) {
443         packet_destroy(spkt, NULL);
444         if (!ppkt) {
445             goto pri;
446         } else {
447             goto sec;
448         }
449     } else {
450         if (conn->compare_seq && !after(spkt->seq_end, conn->compare_seq)) {
451             trace_colo_compare_main("sec: this packet has compared");
452             packet_destroy(spkt, NULL);
453             if (!ppkt) {
454                 goto pri;
455             } else {
456                 goto sec;
457             }
458         }
459         if (!ppkt) {
460             g_queue_push_tail(&conn->secondary_list, spkt);
461             goto pri;
462         }
463     }
464 
465     if (colo_mark_tcp_pkt(ppkt, spkt, &mark, min_ack)) {
466         trace_colo_compare_tcp_info("pri",
467                                     ppkt->tcp_seq, ppkt->tcp_ack,
468                                     ppkt->header_size, ppkt->payload_size,
469                                     ppkt->offset, ppkt->flags);
470 
471         trace_colo_compare_tcp_info("sec",
472                                     spkt->tcp_seq, spkt->tcp_ack,
473                                     spkt->header_size, spkt->payload_size,
474                                     spkt->offset, spkt->flags);
475 
476         if (mark == COLO_COMPARE_FREE_PRIMARY) {
477             conn->compare_seq = ppkt->seq_end;
478             colo_release_primary_pkt(s, ppkt);
479             g_queue_push_tail(&conn->secondary_list, spkt);
480             goto pri;
481         } else if (mark == COLO_COMPARE_FREE_SECONDARY) {
482             conn->compare_seq = spkt->seq_end;
483             packet_destroy(spkt, NULL);
484             goto sec;
485         } else if (mark == (COLO_COMPARE_FREE_PRIMARY | COLO_COMPARE_FREE_SECONDARY)) {
486             conn->compare_seq = ppkt->seq_end;
487             colo_release_primary_pkt(s, ppkt);
488             packet_destroy(spkt, NULL);
489             goto pri;
490         }
491     } else {
492         g_queue_push_tail(&conn->primary_list, ppkt);
493         g_queue_push_tail(&conn->secondary_list, spkt);
494 
495 #ifdef DEBUG_COLO_PACKETS
496         qemu_hexdump(stderr, "colo-compare ppkt", ppkt->data, ppkt->size);
497         qemu_hexdump(stderr, "colo-compare spkt", spkt->data, spkt->size);
498 #endif
499 
500         colo_compare_inconsistency_notify(s);
501     }
502 }
503 
504 
505 /*
506  * Called from the compare thread on the primary
507  * for compare udp packet
508  */
509 static int colo_packet_compare_udp(Packet *spkt, Packet *ppkt)
510 {
511     uint16_t network_header_length = ppkt->ip->ip_hl << 2;
512     uint16_t offset = network_header_length + ETH_HLEN + ppkt->vnet_hdr_len;
513 
514     trace_colo_compare_main("compare udp");
515 
516     /*
517      * Because of ppkt and spkt are both in the same connection,
518      * The ppkt's src ip, dst ip, src port, dst port, ip_proto all are
519      * same with spkt. In addition, IP header's Identification is a random
520      * field, we can handle it in IP fragmentation function later.
521      * COLO just concern the response net packet payload from primary guest
522      * and secondary guest are same or not, So we ignored all IP header include
523      * other field like TOS,TTL,IP Checksum. we only need to compare
524      * the ip payload here.
525      */
526     if (ppkt->size != spkt->size) {
527         trace_colo_compare_main("UDP: payload size of packets are different");
528         return -1;
529     }
530     if (colo_compare_packet_payload(ppkt, spkt, offset, offset,
531                                     ppkt->size - offset)) {
532         trace_colo_compare_udp_miscompare("primary pkt size", ppkt->size);
533         trace_colo_compare_udp_miscompare("Secondary pkt size", spkt->size);
534 #ifdef DEBUG_COLO_PACKETS
535         qemu_hexdump(stderr, "colo-compare pri pkt", ppkt->data, ppkt->size);
536         qemu_hexdump(stderr, "colo-compare sec pkt", spkt->data, spkt->size);
537 #endif
538         return -1;
539     } else {
540         return 0;
541     }
542 }
543 
544 /*
545  * Called from the compare thread on the primary
546  * for compare icmp packet
547  */
548 static int colo_packet_compare_icmp(Packet *spkt, Packet *ppkt)
549 {
550     uint16_t network_header_length = ppkt->ip->ip_hl << 2;
551     uint16_t offset = network_header_length + ETH_HLEN + ppkt->vnet_hdr_len;
552 
553     trace_colo_compare_main("compare icmp");
554 
555     /*
556      * Because of ppkt and spkt are both in the same connection,
557      * The ppkt's src ip, dst ip, src port, dst port, ip_proto all are
558      * same with spkt. In addition, IP header's Identification is a random
559      * field, we can handle it in IP fragmentation function later.
560      * COLO just concern the response net packet payload from primary guest
561      * and secondary guest are same or not, So we ignored all IP header include
562      * other field like TOS,TTL,IP Checksum. we only need to compare
563      * the ip payload here.
564      */
565     if (ppkt->size != spkt->size) {
566         trace_colo_compare_main("ICMP: payload size of packets are different");
567         return -1;
568     }
569     if (colo_compare_packet_payload(ppkt, spkt, offset, offset,
570                                     ppkt->size - offset)) {
571         trace_colo_compare_icmp_miscompare("primary pkt size",
572                                            ppkt->size);
573         trace_colo_compare_icmp_miscompare("Secondary pkt size",
574                                            spkt->size);
575 #ifdef DEBUG_COLO_PACKETS
576         qemu_hexdump(stderr, "colo-compare pri pkt", ppkt->data, ppkt->size);
577         qemu_hexdump(stderr, "colo-compare sec pkt", spkt->data, spkt->size);
578 #endif
579         return -1;
580     } else {
581         return 0;
582     }
583 }
584 
585 /*
586  * Called from the compare thread on the primary
587  * for compare other packet
588  */
589 static int colo_packet_compare_other(Packet *spkt, Packet *ppkt)
590 {
591     uint16_t offset = ppkt->vnet_hdr_len;
592 
593     trace_colo_compare_main("compare other");
594     if (ppkt->size != spkt->size) {
595         trace_colo_compare_main("Other: payload size of packets are different");
596         return -1;
597     }
598     return colo_compare_packet_payload(ppkt, spkt, offset, offset,
599                                        ppkt->size - offset);
600 }
601 
602 static int colo_old_packet_check_one(Packet *pkt, int64_t *check_time)
603 {
604     int64_t now = qemu_clock_get_ms(QEMU_CLOCK_HOST);
605 
606     if ((now - pkt->creation_ms) > (*check_time)) {
607         trace_colo_old_packet_check_found(pkt->creation_ms);
608         return 0;
609     } else {
610         return 1;
611     }
612 }
613 
614 void colo_compare_register_notifier(Notifier *notify)
615 {
616     notifier_list_add(&colo_compare_notifiers, notify);
617 }
618 
619 void colo_compare_unregister_notifier(Notifier *notify)
620 {
621     notifier_remove(notify);
622 }
623 
624 static int colo_old_packet_check_one_conn(Connection *conn,
625                                           CompareState *s)
626 {
627     if (!g_queue_is_empty(&conn->primary_list)) {
628         if (g_queue_find_custom(&conn->primary_list,
629                                 &s->compare_timeout,
630                                 (GCompareFunc)colo_old_packet_check_one))
631             goto out;
632     }
633 
634     if (!g_queue_is_empty(&conn->secondary_list)) {
635         if (g_queue_find_custom(&conn->secondary_list,
636                                 &s->compare_timeout,
637                                 (GCompareFunc)colo_old_packet_check_one))
638             goto out;
639     }
640 
641     return 1;
642 
643 out:
644     /* Do checkpoint will flush old packet */
645     colo_compare_inconsistency_notify(s);
646     return 0;
647 }
648 
649 /*
650  * Look for old packets that the secondary hasn't matched,
651  * if we have some then we have to checkpoint to wake
652  * the secondary up.
653  */
654 static void colo_old_packet_check(void *opaque)
655 {
656     CompareState *s = opaque;
657 
658     /*
659      * If we find one old packet, stop finding job and notify
660      * COLO frame do checkpoint.
661      */
662     g_queue_find_custom(&s->conn_list, s,
663                         (GCompareFunc)colo_old_packet_check_one_conn);
664 }
665 
666 static void colo_compare_packet(CompareState *s, Connection *conn,
667                                 int (*HandlePacket)(Packet *spkt,
668                                 Packet *ppkt))
669 {
670     Packet *pkt = NULL;
671     GList *result = NULL;
672 
673     while (!g_queue_is_empty(&conn->primary_list) &&
674            !g_queue_is_empty(&conn->secondary_list)) {
675         pkt = g_queue_pop_tail(&conn->primary_list);
676         result = g_queue_find_custom(&conn->secondary_list,
677                  pkt, (GCompareFunc)HandlePacket);
678 
679         if (result) {
680             colo_release_primary_pkt(s, pkt);
681             packet_destroy(result->data, NULL);
682             g_queue_delete_link(&conn->secondary_list, result);
683         } else {
684             /*
685              * If one packet arrive late, the secondary_list or
686              * primary_list will be empty, so we can't compare it
687              * until next comparison. If the packets in the list are
688              * timeout, it will trigger a checkpoint request.
689              */
690             trace_colo_compare_main("packet different");
691             g_queue_push_tail(&conn->primary_list, pkt);
692 
693             colo_compare_inconsistency_notify(s);
694             break;
695         }
696     }
697 }
698 
699 /*
700  * Called from the compare thread on the primary
701  * for compare packet with secondary list of the
702  * specified connection when a new packet was
703  * queued to it.
704  */
705 static void colo_compare_connection(void *opaque, void *user_data)
706 {
707     CompareState *s = user_data;
708     Connection *conn = opaque;
709 
710     switch (conn->ip_proto) {
711     case IPPROTO_TCP:
712         colo_compare_tcp(s, conn);
713         break;
714     case IPPROTO_UDP:
715         colo_compare_packet(s, conn, colo_packet_compare_udp);
716         break;
717     case IPPROTO_ICMP:
718         colo_compare_packet(s, conn, colo_packet_compare_icmp);
719         break;
720     default:
721         colo_compare_packet(s, conn, colo_packet_compare_other);
722         break;
723     }
724 }
725 
726 static void coroutine_fn _compare_chr_send(void *opaque)
727 {
728     SendCo *sendco = opaque;
729     CompareState *s = sendco->s;
730     int ret = 0;
731 
732     while (!g_queue_is_empty(&sendco->send_list)) {
733         SendEntry *entry = g_queue_pop_tail(&sendco->send_list);
734         uint32_t len = htonl(entry->size);
735 
736         ret = qemu_chr_fe_write_all(sendco->chr, (uint8_t *)&len, sizeof(len));
737 
738         if (ret != sizeof(len)) {
739             g_free(entry->buf);
740             g_slice_free(SendEntry, entry);
741             goto err;
742         }
743 
744         if (!sendco->notify_remote_frame && s->vnet_hdr) {
745             /*
746              * We send vnet header len make other module(like filter-redirector)
747              * know how to parse net packet correctly.
748              */
749             len = htonl(entry->vnet_hdr_len);
750 
751             ret = qemu_chr_fe_write_all(sendco->chr,
752                                         (uint8_t *)&len,
753                                         sizeof(len));
754 
755             if (ret != sizeof(len)) {
756                 g_free(entry->buf);
757                 g_slice_free(SendEntry, entry);
758                 goto err;
759             }
760         }
761 
762         ret = qemu_chr_fe_write_all(sendco->chr,
763                                     (uint8_t *)entry->buf,
764                                     entry->size);
765 
766         if (ret != entry->size) {
767             g_free(entry->buf);
768             g_slice_free(SendEntry, entry);
769             goto err;
770         }
771 
772         g_free(entry->buf);
773         g_slice_free(SendEntry, entry);
774     }
775 
776     sendco->ret = 0;
777     goto out;
778 
779 err:
780     while (!g_queue_is_empty(&sendco->send_list)) {
781         SendEntry *entry = g_queue_pop_tail(&sendco->send_list);
782         g_free(entry->buf);
783         g_slice_free(SendEntry, entry);
784     }
785     sendco->ret = ret < 0 ? ret : -EIO;
786 out:
787     sendco->co = NULL;
788     sendco->done = true;
789     aio_wait_kick();
790 }
791 
792 static int compare_chr_send(CompareState *s,
793                             uint8_t *buf,
794                             uint32_t size,
795                             uint32_t vnet_hdr_len,
796                             bool notify_remote_frame,
797                             bool zero_copy)
798 {
799     SendCo *sendco;
800     SendEntry *entry;
801 
802     if (notify_remote_frame) {
803         sendco = &s->notify_sendco;
804     } else {
805         sendco = &s->out_sendco;
806     }
807 
808     if (!size) {
809         return -1;
810     }
811 
812     entry = g_slice_new(SendEntry);
813     entry->size = size;
814     entry->vnet_hdr_len = vnet_hdr_len;
815     if (zero_copy) {
816         entry->buf = buf;
817     } else {
818         entry->buf = g_malloc(size);
819         memcpy(entry->buf, buf, size);
820     }
821     g_queue_push_tail(&sendco->send_list, entry);
822 
823     if (sendco->done) {
824         sendco->co = qemu_coroutine_create(_compare_chr_send, sendco);
825         sendco->done = false;
826         qemu_coroutine_enter(sendco->co);
827         if (sendco->done) {
828             /* report early errors */
829             return sendco->ret;
830         }
831     }
832 
833     /* assume success */
834     return 0;
835 }
836 
837 static int compare_chr_can_read(void *opaque)
838 {
839     return COMPARE_READ_LEN_MAX;
840 }
841 
842 /*
843  * Called from the main thread on the primary for packets
844  * arriving over the socket from the primary.
845  */
846 static void compare_pri_chr_in(void *opaque, const uint8_t *buf, int size)
847 {
848     CompareState *s = COLO_COMPARE(opaque);
849     int ret;
850 
851     ret = net_fill_rstate(&s->pri_rs, buf, size);
852     if (ret == -1) {
853         qemu_chr_fe_set_handlers(&s->chr_pri_in, NULL, NULL, NULL, NULL,
854                                  NULL, NULL, true);
855         error_report("colo-compare primary_in error");
856     }
857 }
858 
859 /*
860  * Called from the main thread on the primary for packets
861  * arriving over the socket from the secondary.
862  */
863 static void compare_sec_chr_in(void *opaque, const uint8_t *buf, int size)
864 {
865     CompareState *s = COLO_COMPARE(opaque);
866     int ret;
867 
868     ret = net_fill_rstate(&s->sec_rs, buf, size);
869     if (ret == -1) {
870         qemu_chr_fe_set_handlers(&s->chr_sec_in, NULL, NULL, NULL, NULL,
871                                  NULL, NULL, true);
872         error_report("colo-compare secondary_in error");
873     }
874 }
875 
876 static void compare_notify_chr(void *opaque, const uint8_t *buf, int size)
877 {
878     CompareState *s = COLO_COMPARE(opaque);
879     int ret;
880 
881     ret = net_fill_rstate(&s->notify_rs, buf, size);
882     if (ret == -1) {
883         qemu_chr_fe_set_handlers(&s->chr_notify_dev, NULL, NULL, NULL, NULL,
884                                  NULL, NULL, true);
885         error_report("colo-compare notify_dev error");
886     }
887 }
888 
889 /*
890  * Check old packet regularly so it can watch for any packets
891  * that the secondary hasn't produced equivalents of.
892  */
893 static void check_old_packet_regular(void *opaque)
894 {
895     CompareState *s = opaque;
896 
897     /* if have old packet we will notify checkpoint */
898     colo_old_packet_check(s);
899     timer_mod(s->packet_check_timer, qemu_clock_get_ms(QEMU_CLOCK_HOST) +
900               s->expired_scan_cycle);
901 }
902 
903 /* Public API, Used for COLO frame to notify compare event */
904 void colo_notify_compares_event(void *opaque, int event, Error **errp)
905 {
906     CompareState *s;
907     qemu_mutex_lock(&colo_compare_mutex);
908 
909     if (!colo_compare_active) {
910         qemu_mutex_unlock(&colo_compare_mutex);
911         return;
912     }
913 
914     qemu_mutex_lock(&event_mtx);
915     QTAILQ_FOREACH(s, &net_compares, next) {
916         s->event = event;
917         qemu_bh_schedule(s->event_bh);
918         event_unhandled_count++;
919     }
920     /* Wait all compare threads to finish handling this event */
921     while (event_unhandled_count > 0) {
922         qemu_cond_wait(&event_complete_cond, &event_mtx);
923     }
924 
925     qemu_mutex_unlock(&event_mtx);
926     qemu_mutex_unlock(&colo_compare_mutex);
927 }
928 
929 static void colo_compare_timer_init(CompareState *s)
930 {
931     AioContext *ctx = iothread_get_aio_context(s->iothread);
932 
933     s->packet_check_timer = aio_timer_new(ctx, QEMU_CLOCK_HOST,
934                                 SCALE_MS, check_old_packet_regular,
935                                 s);
936     timer_mod(s->packet_check_timer, qemu_clock_get_ms(QEMU_CLOCK_HOST) +
937               s->expired_scan_cycle);
938 }
939 
940 static void colo_compare_timer_del(CompareState *s)
941 {
942     if (s->packet_check_timer) {
943         timer_free(s->packet_check_timer);
944         s->packet_check_timer = NULL;
945     }
946  }
947 
948 static void colo_flush_packets(void *opaque, void *user_data);
949 
950 static void colo_compare_handle_event(void *opaque)
951 {
952     CompareState *s = opaque;
953 
954     switch (s->event) {
955     case COLO_EVENT_CHECKPOINT:
956         g_queue_foreach(&s->conn_list, colo_flush_packets, s);
957         break;
958     case COLO_EVENT_FAILOVER:
959         break;
960     default:
961         break;
962     }
963 
964     qemu_mutex_lock(&event_mtx);
965     assert(event_unhandled_count > 0);
966     event_unhandled_count--;
967     qemu_cond_broadcast(&event_complete_cond);
968     qemu_mutex_unlock(&event_mtx);
969 }
970 
971 static void colo_compare_iothread(CompareState *s)
972 {
973     AioContext *ctx = iothread_get_aio_context(s->iothread);
974     object_ref(OBJECT(s->iothread));
975     s->worker_context = iothread_get_g_main_context(s->iothread);
976 
977     qemu_chr_fe_set_handlers(&s->chr_pri_in, compare_chr_can_read,
978                              compare_pri_chr_in, NULL, NULL,
979                              s, s->worker_context, true);
980     qemu_chr_fe_set_handlers(&s->chr_sec_in, compare_chr_can_read,
981                              compare_sec_chr_in, NULL, NULL,
982                              s, s->worker_context, true);
983     if (s->notify_dev) {
984         qemu_chr_fe_set_handlers(&s->chr_notify_dev, compare_chr_can_read,
985                                  compare_notify_chr, NULL, NULL,
986                                  s, s->worker_context, true);
987     }
988 
989     colo_compare_timer_init(s);
990     s->event_bh = aio_bh_new(ctx, colo_compare_handle_event, s);
991 }
992 
993 static char *compare_get_pri_indev(Object *obj, Error **errp)
994 {
995     CompareState *s = COLO_COMPARE(obj);
996 
997     return g_strdup(s->pri_indev);
998 }
999 
1000 static void compare_set_pri_indev(Object *obj, const char *value, Error **errp)
1001 {
1002     CompareState *s = COLO_COMPARE(obj);
1003 
1004     g_free(s->pri_indev);
1005     s->pri_indev = g_strdup(value);
1006 }
1007 
1008 static char *compare_get_sec_indev(Object *obj, Error **errp)
1009 {
1010     CompareState *s = COLO_COMPARE(obj);
1011 
1012     return g_strdup(s->sec_indev);
1013 }
1014 
1015 static void compare_set_sec_indev(Object *obj, const char *value, Error **errp)
1016 {
1017     CompareState *s = COLO_COMPARE(obj);
1018 
1019     g_free(s->sec_indev);
1020     s->sec_indev = g_strdup(value);
1021 }
1022 
1023 static char *compare_get_outdev(Object *obj, Error **errp)
1024 {
1025     CompareState *s = COLO_COMPARE(obj);
1026 
1027     return g_strdup(s->outdev);
1028 }
1029 
1030 static void compare_set_outdev(Object *obj, const char *value, Error **errp)
1031 {
1032     CompareState *s = COLO_COMPARE(obj);
1033 
1034     g_free(s->outdev);
1035     s->outdev = g_strdup(value);
1036 }
1037 
1038 static bool compare_get_vnet_hdr(Object *obj, Error **errp)
1039 {
1040     CompareState *s = COLO_COMPARE(obj);
1041 
1042     return s->vnet_hdr;
1043 }
1044 
1045 static void compare_set_vnet_hdr(Object *obj,
1046                                  bool value,
1047                                  Error **errp)
1048 {
1049     CompareState *s = COLO_COMPARE(obj);
1050 
1051     s->vnet_hdr = value;
1052 }
1053 
1054 static char *compare_get_notify_dev(Object *obj, Error **errp)
1055 {
1056     CompareState *s = COLO_COMPARE(obj);
1057 
1058     return g_strdup(s->notify_dev);
1059 }
1060 
1061 static void compare_set_notify_dev(Object *obj, const char *value, Error **errp)
1062 {
1063     CompareState *s = COLO_COMPARE(obj);
1064 
1065     g_free(s->notify_dev);
1066     s->notify_dev = g_strdup(value);
1067 }
1068 
1069 static void compare_get_timeout(Object *obj, Visitor *v,
1070                                 const char *name, void *opaque,
1071                                 Error **errp)
1072 {
1073     CompareState *s = COLO_COMPARE(obj);
1074     uint64_t value = s->compare_timeout;
1075 
1076     visit_type_uint64(v, name, &value, errp);
1077 }
1078 
1079 static void compare_set_timeout(Object *obj, Visitor *v,
1080                                 const char *name, void *opaque,
1081                                 Error **errp)
1082 {
1083     CompareState *s = COLO_COMPARE(obj);
1084     uint32_t value;
1085 
1086     if (!visit_type_uint32(v, name, &value, errp)) {
1087         return;
1088     }
1089     if (!value) {
1090         error_setg(errp, "Property '%s.%s' requires a positive value",
1091                    object_get_typename(obj), name);
1092         return;
1093     }
1094     s->compare_timeout = value;
1095 }
1096 
1097 static void compare_get_expired_scan_cycle(Object *obj, Visitor *v,
1098                                            const char *name, void *opaque,
1099                                            Error **errp)
1100 {
1101     CompareState *s = COLO_COMPARE(obj);
1102     uint32_t value = s->expired_scan_cycle;
1103 
1104     visit_type_uint32(v, name, &value, errp);
1105 }
1106 
1107 static void compare_set_expired_scan_cycle(Object *obj, Visitor *v,
1108                                            const char *name, void *opaque,
1109                                            Error **errp)
1110 {
1111     CompareState *s = COLO_COMPARE(obj);
1112     uint32_t value;
1113 
1114     if (!visit_type_uint32(v, name, &value, errp)) {
1115         return;
1116     }
1117     if (!value) {
1118         error_setg(errp, "Property '%s.%s' requires a positive value",
1119                    object_get_typename(obj), name);
1120         return;
1121     }
1122     s->expired_scan_cycle = value;
1123 }
1124 
1125 static void get_max_queue_size(Object *obj, Visitor *v,
1126                                const char *name, void *opaque,
1127                                Error **errp)
1128 {
1129     uint32_t value = max_queue_size;
1130 
1131     visit_type_uint32(v, name, &value, errp);
1132 }
1133 
1134 static void set_max_queue_size(Object *obj, Visitor *v,
1135                                const char *name, void *opaque,
1136                                Error **errp)
1137 {
1138     uint64_t value;
1139 
1140     if (!visit_type_uint64(v, name, &value, errp)) {
1141         return;
1142     }
1143     if (!value) {
1144         error_setg(errp, "Property '%s.%s' requires a positive value",
1145                    object_get_typename(obj), name);
1146         return;
1147     }
1148     max_queue_size = value;
1149 }
1150 
1151 static void compare_pri_rs_finalize(SocketReadState *pri_rs)
1152 {
1153     CompareState *s = container_of(pri_rs, CompareState, pri_rs);
1154     Connection *conn = NULL;
1155 
1156     if (packet_enqueue(s, PRIMARY_IN, &conn)) {
1157         trace_colo_compare_main("primary: unsupported packet in");
1158         compare_chr_send(s,
1159                          pri_rs->buf,
1160                          pri_rs->packet_len,
1161                          pri_rs->vnet_hdr_len,
1162                          false,
1163                          false);
1164     } else {
1165         /* compare packet in the specified connection */
1166         colo_compare_connection(conn, s);
1167     }
1168 }
1169 
1170 static void compare_sec_rs_finalize(SocketReadState *sec_rs)
1171 {
1172     CompareState *s = container_of(sec_rs, CompareState, sec_rs);
1173     Connection *conn = NULL;
1174 
1175     if (packet_enqueue(s, SECONDARY_IN, &conn)) {
1176         trace_colo_compare_main("secondary: unsupported packet in");
1177     } else {
1178         /* compare packet in the specified connection */
1179         colo_compare_connection(conn, s);
1180     }
1181 }
1182 
1183 static void compare_notify_rs_finalize(SocketReadState *notify_rs)
1184 {
1185     CompareState *s = container_of(notify_rs, CompareState, notify_rs);
1186 
1187     const char msg[] = "COLO_COMPARE_GET_XEN_INIT";
1188     int ret;
1189 
1190     if (packet_matches_str("COLO_USERSPACE_PROXY_INIT",
1191                            notify_rs->buf,
1192                            notify_rs->packet_len)) {
1193         ret = compare_chr_send(s, (uint8_t *)msg, strlen(msg), 0, true, false);
1194         if (ret < 0) {
1195             error_report("Notify Xen COLO-frame INIT failed");
1196         }
1197     } else if (packet_matches_str("COLO_CHECKPOINT",
1198                                   notify_rs->buf,
1199                                   notify_rs->packet_len)) {
1200         /* colo-compare do checkpoint, flush pri packet and remove sec packet */
1201         g_queue_foreach(&s->conn_list, colo_flush_packets, s);
1202     } else {
1203         error_report("COLO compare got unsupported instruction");
1204     }
1205 }
1206 
1207 /*
1208  * Return 0 is success.
1209  * Return 1 is failed.
1210  */
1211 static int find_and_check_chardev(Chardev **chr,
1212                                   char *chr_name,
1213                                   Error **errp)
1214 {
1215     *chr = qemu_chr_find(chr_name);
1216     if (*chr == NULL) {
1217         error_setg(errp, "Device '%s' not found",
1218                    chr_name);
1219         return 1;
1220     }
1221 
1222     if (!qemu_chr_has_feature(*chr, QEMU_CHAR_FEATURE_RECONNECTABLE)) {
1223         error_setg(errp, "chardev \"%s\" is not reconnectable",
1224                    chr_name);
1225         return 1;
1226     }
1227 
1228     if (!qemu_chr_has_feature(*chr, QEMU_CHAR_FEATURE_GCONTEXT)) {
1229         error_setg(errp, "chardev \"%s\" cannot switch context",
1230                    chr_name);
1231         return 1;
1232     }
1233 
1234     return 0;
1235 }
1236 
1237 /*
1238  * Called from the main thread on the primary
1239  * to setup colo-compare.
1240  */
1241 static void colo_compare_complete(UserCreatable *uc, Error **errp)
1242 {
1243     CompareState *s = COLO_COMPARE(uc);
1244     Chardev *chr;
1245 
1246     if (!s->pri_indev || !s->sec_indev || !s->outdev || !s->iothread) {
1247         error_setg(errp, "colo compare needs 'primary_in' ,"
1248                    "'secondary_in','outdev','iothread' property set");
1249         return;
1250     } else if (!strcmp(s->pri_indev, s->outdev) ||
1251                !strcmp(s->sec_indev, s->outdev) ||
1252                !strcmp(s->pri_indev, s->sec_indev)) {
1253         error_setg(errp, "'indev' and 'outdev' could not be same "
1254                    "for compare module");
1255         return;
1256     }
1257 
1258     if (!s->compare_timeout) {
1259         /* Set default value to 3000 MS */
1260         s->compare_timeout = DEFAULT_TIME_OUT_MS;
1261     }
1262 
1263     if (!s->expired_scan_cycle) {
1264         /* Set default value to 1000 MS */
1265         s->expired_scan_cycle = REGULAR_PACKET_CHECK_MS;
1266     }
1267 
1268     if (!max_queue_size) {
1269         /* Set default queue size to 1024 */
1270         max_queue_size = MAX_QUEUE_SIZE;
1271     }
1272 
1273     if (find_and_check_chardev(&chr, s->pri_indev, errp) ||
1274         !qemu_chr_fe_init(&s->chr_pri_in, chr, errp)) {
1275         return;
1276     }
1277 
1278     if (find_and_check_chardev(&chr, s->sec_indev, errp) ||
1279         !qemu_chr_fe_init(&s->chr_sec_in, chr, errp)) {
1280         return;
1281     }
1282 
1283     if (find_and_check_chardev(&chr, s->outdev, errp) ||
1284         !qemu_chr_fe_init(&s->chr_out, chr, errp)) {
1285         return;
1286     }
1287 
1288     net_socket_rs_init(&s->pri_rs, compare_pri_rs_finalize, s->vnet_hdr);
1289     net_socket_rs_init(&s->sec_rs, compare_sec_rs_finalize, s->vnet_hdr);
1290 
1291     /* Try to enable remote notify chardev, currently just for Xen COLO */
1292     if (s->notify_dev) {
1293         if (find_and_check_chardev(&chr, s->notify_dev, errp) ||
1294             !qemu_chr_fe_init(&s->chr_notify_dev, chr, errp)) {
1295             return;
1296         }
1297 
1298         net_socket_rs_init(&s->notify_rs, compare_notify_rs_finalize,
1299                            s->vnet_hdr);
1300     }
1301 
1302     s->out_sendco.s = s;
1303     s->out_sendco.chr = &s->chr_out;
1304     s->out_sendco.notify_remote_frame = false;
1305     s->out_sendco.done = true;
1306     g_queue_init(&s->out_sendco.send_list);
1307 
1308     if (s->notify_dev) {
1309         s->notify_sendco.s = s;
1310         s->notify_sendco.chr = &s->chr_notify_dev;
1311         s->notify_sendco.notify_remote_frame = true;
1312         s->notify_sendco.done = true;
1313         g_queue_init(&s->notify_sendco.send_list);
1314     }
1315 
1316     g_queue_init(&s->conn_list);
1317 
1318     s->connection_track_table = g_hash_table_new_full(connection_key_hash,
1319                                                       connection_key_equal,
1320                                                       g_free,
1321                                                       NULL);
1322 
1323     colo_compare_iothread(s);
1324 
1325     qemu_mutex_lock(&colo_compare_mutex);
1326     if (!colo_compare_active) {
1327         qemu_mutex_init(&event_mtx);
1328         qemu_cond_init(&event_complete_cond);
1329         colo_compare_active = true;
1330     }
1331     QTAILQ_INSERT_TAIL(&net_compares, s, next);
1332     qemu_mutex_unlock(&colo_compare_mutex);
1333 
1334     return;
1335 }
1336 
1337 static void colo_flush_packets(void *opaque, void *user_data)
1338 {
1339     CompareState *s = user_data;
1340     Connection *conn = opaque;
1341     Packet *pkt = NULL;
1342 
1343     while (!g_queue_is_empty(&conn->primary_list)) {
1344         pkt = g_queue_pop_tail(&conn->primary_list);
1345         compare_chr_send(s,
1346                          pkt->data,
1347                          pkt->size,
1348                          pkt->vnet_hdr_len,
1349                          false,
1350                          true);
1351         packet_destroy_partial(pkt, NULL);
1352     }
1353     while (!g_queue_is_empty(&conn->secondary_list)) {
1354         pkt = g_queue_pop_tail(&conn->secondary_list);
1355         packet_destroy(pkt, NULL);
1356     }
1357 }
1358 
1359 static void colo_compare_class_init(ObjectClass *oc, void *data)
1360 {
1361     UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);
1362 
1363     ucc->complete = colo_compare_complete;
1364 }
1365 
1366 static void colo_compare_init(Object *obj)
1367 {
1368     CompareState *s = COLO_COMPARE(obj);
1369 
1370     object_property_add_str(obj, "primary_in",
1371                             compare_get_pri_indev, compare_set_pri_indev);
1372     object_property_add_str(obj, "secondary_in",
1373                             compare_get_sec_indev, compare_set_sec_indev);
1374     object_property_add_str(obj, "outdev",
1375                             compare_get_outdev, compare_set_outdev);
1376     object_property_add_link(obj, "iothread", TYPE_IOTHREAD,
1377                             (Object **)&s->iothread,
1378                             object_property_allow_set_link,
1379                             OBJ_PROP_LINK_STRONG);
1380     /* This parameter just for Xen COLO */
1381     object_property_add_str(obj, "notify_dev",
1382                             compare_get_notify_dev, compare_set_notify_dev);
1383 
1384     object_property_add(obj, "compare_timeout", "uint64",
1385                         compare_get_timeout,
1386                         compare_set_timeout, NULL, NULL);
1387 
1388     object_property_add(obj, "expired_scan_cycle", "uint32",
1389                         compare_get_expired_scan_cycle,
1390                         compare_set_expired_scan_cycle, NULL, NULL);
1391 
1392     object_property_add(obj, "max_queue_size", "uint32",
1393                         get_max_queue_size,
1394                         set_max_queue_size, NULL, NULL);
1395 
1396     s->vnet_hdr = false;
1397     object_property_add_bool(obj, "vnet_hdr_support", compare_get_vnet_hdr,
1398                              compare_set_vnet_hdr);
1399 }
1400 
1401 void colo_compare_cleanup(void)
1402 {
1403     CompareState *tmp = NULL;
1404     CompareState *n = NULL;
1405 
1406     QTAILQ_FOREACH_SAFE(tmp, &net_compares, next, n) {
1407         object_unparent(OBJECT(tmp));
1408     }
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