xref: /openbmc/qemu/net/colo-compare.c (revision 354908ce)
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 #define COLO_COMPARE(obj) \
40     OBJECT_CHECK(CompareState, (obj), 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 3000
55 #define DEFAULT_TIME_OUT_MS 3000
56 
57 static QemuMutex colo_compare_mutex;
58 static bool colo_compare_active;
59 static QemuMutex event_mtx;
60 static QemuCond event_complete_cond;
61 static int event_unhandled_count;
62 
63 /*
64  *  + CompareState ++
65  *  |               |
66  *  +---------------+   +---------------+         +---------------+
67  *  |   conn list   + - >      conn     + ------- >      conn     + -- > ......
68  *  +---------------+   +---------------+         +---------------+
69  *  |               |     |           |             |          |
70  *  +---------------+ +---v----+  +---v----+    +---v----+ +---v----+
71  *                    |primary |  |secondary    |primary | |secondary
72  *                    |packet  |  |packet  +    |packet  | |packet  +
73  *                    +--------+  +--------+    +--------+ +--------+
74  *                        |           |             |          |
75  *                    +---v----+  +---v----+    +---v----+ +---v----+
76  *                    |primary |  |secondary    |primary | |secondary
77  *                    |packet  |  |packet  +    |packet  | |packet  +
78  *                    +--------+  +--------+    +--------+ +--------+
79  *                        |           |             |          |
80  *                    +---v----+  +---v----+    +---v----+ +---v----+
81  *                    |primary |  |secondary    |primary | |secondary
82  *                    |packet  |  |packet  +    |packet  | |packet  +
83  *                    +--------+  +--------+    +--------+ +--------+
84  */
85 
86 typedef struct SendCo {
87     Coroutine *co;
88     struct CompareState *s;
89     CharBackend *chr;
90     GQueue send_list;
91     bool notify_remote_frame;
92     bool done;
93     int ret;
94 } SendCo;
95 
96 typedef struct SendEntry {
97     uint32_t size;
98     uint32_t vnet_hdr_len;
99     uint8_t *buf;
100 } SendEntry;
101 
102 typedef struct CompareState {
103     Object parent;
104 
105     char *pri_indev;
106     char *sec_indev;
107     char *outdev;
108     char *notify_dev;
109     CharBackend chr_pri_in;
110     CharBackend chr_sec_in;
111     CharBackend chr_out;
112     CharBackend chr_notify_dev;
113     SocketReadState pri_rs;
114     SocketReadState sec_rs;
115     SocketReadState notify_rs;
116     SendCo out_sendco;
117     SendCo notify_sendco;
118     bool vnet_hdr;
119     uint32_t compare_timeout;
120     uint32_t expired_scan_cycle;
121 
122     /*
123      * Record the connection that through the NIC
124      * Element type: Connection
125      */
126     GQueue conn_list;
127     /* Record the connection without repetition */
128     GHashTable *connection_track_table;
129 
130     IOThread *iothread;
131     GMainContext *worker_context;
132     QEMUTimer *packet_check_timer;
133 
134     QEMUBH *event_bh;
135     enum colo_event event;
136 
137     QTAILQ_ENTRY(CompareState) next;
138 } CompareState;
139 
140 typedef struct CompareClass {
141     ObjectClass parent_class;
142 } CompareClass;
143 
144 enum {
145     PRIMARY_IN = 0,
146     SECONDARY_IN,
147 };
148 
149 static const char *colo_mode[] = {
150     [PRIMARY_IN] = "primary",
151     [SECONDARY_IN] = "secondary",
152 };
153 
154 static int compare_chr_send(CompareState *s,
155                             uint8_t *buf,
156                             uint32_t size,
157                             uint32_t vnet_hdr_len,
158                             bool notify_remote_frame,
159                             bool zero_copy);
160 
161 static bool packet_matches_str(const char *str,
162                                const uint8_t *buf,
163                                uint32_t packet_len)
164 {
165     if (packet_len != strlen(str)) {
166         return false;
167     }
168 
169     return !memcmp(str, buf, strlen(str));
170 }
171 
172 static void notify_remote_frame(CompareState *s)
173 {
174     char msg[] = "DO_CHECKPOINT";
175     int ret = 0;
176 
177     ret = compare_chr_send(s, (uint8_t *)msg, strlen(msg), 0, true, false);
178     if (ret < 0) {
179         error_report("Notify Xen COLO-frame failed");
180     }
181 }
182 
183 static void colo_compare_inconsistency_notify(CompareState *s)
184 {
185     if (s->notify_dev) {
186         notify_remote_frame(s);
187     } else {
188         notifier_list_notify(&colo_compare_notifiers,
189                              migrate_get_current());
190     }
191 }
192 
193 static gint seq_sorter(Packet *a, Packet *b, gpointer data)
194 {
195     struct tcp_hdr *atcp, *btcp;
196 
197     atcp = (struct tcp_hdr *)(a->transport_header);
198     btcp = (struct tcp_hdr *)(b->transport_header);
199     return ntohl(atcp->th_seq) - ntohl(btcp->th_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     *max_ack = *max_ack > pkt->tcp_ack ? *max_ack : pkt->tcp_ack;
212     pkt->header_size = pkt->transport_header - (uint8_t *)pkt->data
213                        + (tcphd->th_off << 2) - pkt->vnet_hdr_len;
214     pkt->payload_size = pkt->size - pkt->header_size;
215     pkt->seq_end = pkt->tcp_seq + pkt->payload_size;
216     pkt->flags = tcphd->th_flags;
217 }
218 
219 /*
220  * Return 1 on success, if return 0 means the
221  * packet will be dropped
222  */
223 static int colo_insert_packet(GQueue *queue, Packet *pkt, uint32_t *max_ack)
224 {
225     if (g_queue_get_length(queue) <= MAX_QUEUE_SIZE) {
226         if (pkt->ip->ip_p == IPPROTO_TCP) {
227             fill_pkt_tcp_info(pkt, max_ack);
228             g_queue_insert_sorted(queue,
229                                   pkt,
230                                   (GCompareDataFunc)seq_sorter,
231                                   NULL);
232         } else {
233             g_queue_push_tail(queue, pkt);
234         }
235         return 1;
236     }
237     return 0;
238 }
239 
240 /*
241  * Return 0 on success, if return -1 means the pkt
242  * is unsupported(arp and ipv6) and will be sent later
243  */
244 static int packet_enqueue(CompareState *s, int mode, Connection **con)
245 {
246     ConnectionKey key;
247     Packet *pkt = NULL;
248     Connection *conn;
249     int ret;
250 
251     if (mode == PRIMARY_IN) {
252         pkt = packet_new(s->pri_rs.buf,
253                          s->pri_rs.packet_len,
254                          s->pri_rs.vnet_hdr_len);
255     } else {
256         pkt = packet_new(s->sec_rs.buf,
257                          s->sec_rs.packet_len,
258                          s->sec_rs.vnet_hdr_len);
259     }
260 
261     if (parse_packet_early(pkt)) {
262         packet_destroy(pkt, NULL);
263         pkt = NULL;
264         return -1;
265     }
266     fill_connection_key(pkt, &key);
267 
268     conn = connection_get(s->connection_track_table,
269                           &key,
270                           &s->conn_list);
271 
272     if (!conn->processing) {
273         g_queue_push_tail(&s->conn_list, conn);
274         conn->processing = true;
275     }
276 
277     if (mode == PRIMARY_IN) {
278         ret = colo_insert_packet(&conn->primary_list, pkt, &conn->pack);
279     } else {
280         ret = colo_insert_packet(&conn->secondary_list, pkt, &conn->sack);
281     }
282 
283     if (!ret) {
284         trace_colo_compare_drop_packet(colo_mode[mode],
285             "queue size too big, drop packet");
286         packet_destroy(pkt, NULL);
287         pkt = NULL;
288     }
289 
290     *con = conn;
291 
292     return 0;
293 }
294 
295 static inline bool after(uint32_t seq1, uint32_t seq2)
296 {
297         return (int32_t)(seq1 - seq2) > 0;
298 }
299 
300 static void colo_release_primary_pkt(CompareState *s, Packet *pkt)
301 {
302     int ret;
303     ret = compare_chr_send(s,
304                            pkt->data,
305                            pkt->size,
306                            pkt->vnet_hdr_len,
307                            false,
308                            true);
309     if (ret < 0) {
310         error_report("colo send primary packet failed");
311     }
312     trace_colo_compare_main("packet same and release packet");
313     packet_destroy_partial(pkt, NULL);
314 }
315 
316 /*
317  * The IP packets sent by primary and secondary
318  * will be compared in here
319  * TODO support ip fragment, Out-Of-Order
320  * return:    0  means packet same
321  *            > 0 || < 0 means packet different
322  */
323 static int colo_compare_packet_payload(Packet *ppkt,
324                                        Packet *spkt,
325                                        uint16_t poffset,
326                                        uint16_t soffset,
327                                        uint16_t len)
328 
329 {
330     if (trace_event_get_state_backends(TRACE_COLO_COMPARE_MISCOMPARE)) {
331         char pri_ip_src[20], pri_ip_dst[20], sec_ip_src[20], sec_ip_dst[20];
332 
333         strcpy(pri_ip_src, inet_ntoa(ppkt->ip->ip_src));
334         strcpy(pri_ip_dst, inet_ntoa(ppkt->ip->ip_dst));
335         strcpy(sec_ip_src, inet_ntoa(spkt->ip->ip_src));
336         strcpy(sec_ip_dst, inet_ntoa(spkt->ip->ip_dst));
337 
338         trace_colo_compare_ip_info(ppkt->size, pri_ip_src,
339                                    pri_ip_dst, spkt->size,
340                                    sec_ip_src, sec_ip_dst);
341     }
342 
343     return memcmp(ppkt->data + poffset, spkt->data + soffset, len);
344 }
345 
346 /*
347  * return true means that the payload is consist and
348  * need to make the next comparison, false means do
349  * the checkpoint
350 */
351 static bool colo_mark_tcp_pkt(Packet *ppkt, Packet *spkt,
352                               int8_t *mark, uint32_t max_ack)
353 {
354     *mark = 0;
355 
356     if (ppkt->tcp_seq == spkt->tcp_seq && ppkt->seq_end == spkt->seq_end) {
357         if (!colo_compare_packet_payload(ppkt, spkt,
358                                         ppkt->header_size, spkt->header_size,
359                                         ppkt->payload_size)) {
360             *mark = COLO_COMPARE_FREE_SECONDARY | COLO_COMPARE_FREE_PRIMARY;
361             return true;
362         }
363     }
364 
365     /* one part of secondary packet payload still need to be compared */
366     if (!after(ppkt->seq_end, spkt->seq_end)) {
367         if (!colo_compare_packet_payload(ppkt, spkt,
368                                         ppkt->header_size + ppkt->offset,
369                                         spkt->header_size + spkt->offset,
370                                         ppkt->payload_size - ppkt->offset)) {
371             if (!after(ppkt->tcp_ack, max_ack)) {
372                 *mark = COLO_COMPARE_FREE_PRIMARY;
373                 spkt->offset += ppkt->payload_size - ppkt->offset;
374                 return true;
375             } else {
376                 /* secondary guest hasn't ack the data, don't send
377                  * out this packet
378                  */
379                 return false;
380             }
381         }
382     } else {
383         /* primary packet is longer than secondary packet, compare
384          * the same part and mark the primary packet offset
385          */
386         if (!colo_compare_packet_payload(ppkt, spkt,
387                                         ppkt->header_size + ppkt->offset,
388                                         spkt->header_size + spkt->offset,
389                                         spkt->payload_size - spkt->offset)) {
390             *mark = COLO_COMPARE_FREE_SECONDARY;
391             ppkt->offset += spkt->payload_size - spkt->offset;
392             return true;
393         }
394     }
395 
396     return false;
397 }
398 
399 static void colo_compare_tcp(CompareState *s, Connection *conn)
400 {
401     Packet *ppkt = NULL, *spkt = NULL;
402     int8_t mark;
403 
404     /*
405      * If ppkt and spkt have the same payload, but ppkt's ACK
406      * is greater than spkt's ACK, in this case we can not
407      * send the ppkt because it will cause the secondary guest
408      * to miss sending some data in the next. Therefore, we
409      * record the maximum ACK in the current queue at both
410      * primary side and secondary side. Only when the ack is
411      * less than the smaller of the two maximum ack, then we
412      * can ensure that the packet's payload is acknowledged by
413      * primary and secondary.
414     */
415     uint32_t min_ack = conn->pack > conn->sack ? conn->sack : conn->pack;
416 
417 pri:
418     if (g_queue_is_empty(&conn->primary_list)) {
419         return;
420     }
421     ppkt = g_queue_pop_head(&conn->primary_list);
422 sec:
423     if (g_queue_is_empty(&conn->secondary_list)) {
424         g_queue_push_head(&conn->primary_list, ppkt);
425         return;
426     }
427     spkt = g_queue_pop_head(&conn->secondary_list);
428 
429     if (ppkt->tcp_seq == ppkt->seq_end) {
430         colo_release_primary_pkt(s, ppkt);
431         ppkt = NULL;
432     }
433 
434     if (ppkt && conn->compare_seq && !after(ppkt->seq_end, conn->compare_seq)) {
435         trace_colo_compare_main("pri: this packet has compared");
436         colo_release_primary_pkt(s, ppkt);
437         ppkt = NULL;
438     }
439 
440     if (spkt->tcp_seq == spkt->seq_end) {
441         packet_destroy(spkt, NULL);
442         if (!ppkt) {
443             goto pri;
444         } else {
445             goto sec;
446         }
447     } else {
448         if (conn->compare_seq && !after(spkt->seq_end, conn->compare_seq)) {
449             trace_colo_compare_main("sec: this packet has compared");
450             packet_destroy(spkt, NULL);
451             if (!ppkt) {
452                 goto pri;
453             } else {
454                 goto sec;
455             }
456         }
457         if (!ppkt) {
458             g_queue_push_head(&conn->secondary_list, spkt);
459             goto pri;
460         }
461     }
462 
463     if (colo_mark_tcp_pkt(ppkt, spkt, &mark, min_ack)) {
464         trace_colo_compare_tcp_info("pri",
465                                     ppkt->tcp_seq, ppkt->tcp_ack,
466                                     ppkt->header_size, ppkt->payload_size,
467                                     ppkt->offset, ppkt->flags);
468 
469         trace_colo_compare_tcp_info("sec",
470                                     spkt->tcp_seq, spkt->tcp_ack,
471                                     spkt->header_size, spkt->payload_size,
472                                     spkt->offset, spkt->flags);
473 
474         if (mark == COLO_COMPARE_FREE_PRIMARY) {
475             conn->compare_seq = ppkt->seq_end;
476             colo_release_primary_pkt(s, ppkt);
477             g_queue_push_head(&conn->secondary_list, spkt);
478             goto pri;
479         }
480         if (mark == COLO_COMPARE_FREE_SECONDARY) {
481             conn->compare_seq = spkt->seq_end;
482             packet_destroy(spkt, NULL);
483             goto sec;
484         }
485         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_head(&conn->primary_list, ppkt);
493         g_queue_push_head(&conn->secondary_list, spkt);
494 
495         if (trace_event_get_state_backends(TRACE_COLO_COMPARE_MISCOMPARE)) {
496             qemu_hexdump((char *)ppkt->data, stderr,
497                         "colo-compare ppkt", ppkt->size);
498             qemu_hexdump((char *)spkt->data, stderr,
499                         "colo-compare spkt", spkt->size);
500         }
501 
502         colo_compare_inconsistency_notify(s);
503     }
504 }
505 
506 
507 /*
508  * Called from the compare thread on the primary
509  * for compare udp packet
510  */
511 static int colo_packet_compare_udp(Packet *spkt, Packet *ppkt)
512 {
513     uint16_t network_header_length = ppkt->ip->ip_hl << 2;
514     uint16_t offset = network_header_length + ETH_HLEN + ppkt->vnet_hdr_len;
515 
516     trace_colo_compare_main("compare udp");
517 
518     /*
519      * Because of ppkt and spkt are both in the same connection,
520      * The ppkt's src ip, dst ip, src port, dst port, ip_proto all are
521      * same with spkt. In addition, IP header's Identification is a random
522      * field, we can handle it in IP fragmentation function later.
523      * COLO just concern the response net packet payload from primary guest
524      * and secondary guest are same or not, So we ignored all IP header include
525      * other field like TOS,TTL,IP Checksum. we only need to compare
526      * the ip payload here.
527      */
528     if (ppkt->size != spkt->size) {
529         trace_colo_compare_main("UDP: payload size of packets are different");
530         return -1;
531     }
532     if (colo_compare_packet_payload(ppkt, spkt, offset, offset,
533                                     ppkt->size - offset)) {
534         trace_colo_compare_udp_miscompare("primary pkt size", ppkt->size);
535         trace_colo_compare_udp_miscompare("Secondary pkt size", spkt->size);
536         if (trace_event_get_state_backends(TRACE_COLO_COMPARE_MISCOMPARE)) {
537             qemu_hexdump((char *)ppkt->data, stderr, "colo-compare pri pkt",
538                          ppkt->size);
539             qemu_hexdump((char *)spkt->data, stderr, "colo-compare sec pkt",
540                          spkt->size);
541         }
542         return -1;
543     } else {
544         return 0;
545     }
546 }
547 
548 /*
549  * Called from the compare thread on the primary
550  * for compare icmp packet
551  */
552 static int colo_packet_compare_icmp(Packet *spkt, Packet *ppkt)
553 {
554     uint16_t network_header_length = ppkt->ip->ip_hl << 2;
555     uint16_t offset = network_header_length + ETH_HLEN + ppkt->vnet_hdr_len;
556 
557     trace_colo_compare_main("compare icmp");
558 
559     /*
560      * Because of ppkt and spkt are both in the same connection,
561      * The ppkt's src ip, dst ip, src port, dst port, ip_proto all are
562      * same with spkt. In addition, IP header's Identification is a random
563      * field, we can handle it in IP fragmentation function later.
564      * COLO just concern the response net packet payload from primary guest
565      * and secondary guest are same or not, So we ignored all IP header include
566      * other field like TOS,TTL,IP Checksum. we only need to compare
567      * the ip payload here.
568      */
569     if (ppkt->size != spkt->size) {
570         trace_colo_compare_main("ICMP: payload size of packets are different");
571         return -1;
572     }
573     if (colo_compare_packet_payload(ppkt, spkt, offset, offset,
574                                     ppkt->size - offset)) {
575         trace_colo_compare_icmp_miscompare("primary pkt size",
576                                            ppkt->size);
577         trace_colo_compare_icmp_miscompare("Secondary pkt size",
578                                            spkt->size);
579         if (trace_event_get_state_backends(TRACE_COLO_COMPARE_MISCOMPARE)) {
580             qemu_hexdump((char *)ppkt->data, stderr, "colo-compare pri pkt",
581                          ppkt->size);
582             qemu_hexdump((char *)spkt->data, stderr, "colo-compare sec pkt",
583                          spkt->size);
584         }
585         return -1;
586     } else {
587         return 0;
588     }
589 }
590 
591 /*
592  * Called from the compare thread on the primary
593  * for compare other packet
594  */
595 static int colo_packet_compare_other(Packet *spkt, Packet *ppkt)
596 {
597     uint16_t offset = ppkt->vnet_hdr_len;
598 
599     trace_colo_compare_main("compare other");
600     if (trace_event_get_state_backends(TRACE_COLO_COMPARE_MISCOMPARE)) {
601         char pri_ip_src[20], pri_ip_dst[20], sec_ip_src[20], sec_ip_dst[20];
602 
603         strcpy(pri_ip_src, inet_ntoa(ppkt->ip->ip_src));
604         strcpy(pri_ip_dst, inet_ntoa(ppkt->ip->ip_dst));
605         strcpy(sec_ip_src, inet_ntoa(spkt->ip->ip_src));
606         strcpy(sec_ip_dst, inet_ntoa(spkt->ip->ip_dst));
607 
608         trace_colo_compare_ip_info(ppkt->size, pri_ip_src,
609                                    pri_ip_dst, spkt->size,
610                                    sec_ip_src, sec_ip_dst);
611     }
612 
613     if (ppkt->size != spkt->size) {
614         trace_colo_compare_main("Other: payload size of packets are different");
615         return -1;
616     }
617     return colo_compare_packet_payload(ppkt, spkt, offset, offset,
618                                        ppkt->size - offset);
619 }
620 
621 static int colo_old_packet_check_one(Packet *pkt, int64_t *check_time)
622 {
623     int64_t now = qemu_clock_get_ms(QEMU_CLOCK_HOST);
624 
625     if ((now - pkt->creation_ms) > (*check_time)) {
626         trace_colo_old_packet_check_found(pkt->creation_ms);
627         return 0;
628     } else {
629         return 1;
630     }
631 }
632 
633 void colo_compare_register_notifier(Notifier *notify)
634 {
635     notifier_list_add(&colo_compare_notifiers, notify);
636 }
637 
638 void colo_compare_unregister_notifier(Notifier *notify)
639 {
640     notifier_remove(notify);
641 }
642 
643 static int colo_old_packet_check_one_conn(Connection *conn,
644                                           CompareState *s)
645 {
646     GList *result = NULL;
647 
648     result = g_queue_find_custom(&conn->primary_list,
649                                  &s->compare_timeout,
650                                  (GCompareFunc)colo_old_packet_check_one);
651 
652     if (result) {
653         /* Do checkpoint will flush old packet */
654         colo_compare_inconsistency_notify(s);
655         return 0;
656     }
657 
658     return 1;
659 }
660 
661 /*
662  * Look for old packets that the secondary hasn't matched,
663  * if we have some then we have to checkpoint to wake
664  * the secondary up.
665  */
666 static void colo_old_packet_check(void *opaque)
667 {
668     CompareState *s = opaque;
669 
670     /*
671      * If we find one old packet, stop finding job and notify
672      * COLO frame do checkpoint.
673      */
674     g_queue_find_custom(&s->conn_list, s,
675                         (GCompareFunc)colo_old_packet_check_one_conn);
676 }
677 
678 static void colo_compare_packet(CompareState *s, Connection *conn,
679                                 int (*HandlePacket)(Packet *spkt,
680                                 Packet *ppkt))
681 {
682     Packet *pkt = NULL;
683     GList *result = NULL;
684 
685     while (!g_queue_is_empty(&conn->primary_list) &&
686            !g_queue_is_empty(&conn->secondary_list)) {
687         pkt = g_queue_pop_head(&conn->primary_list);
688         result = g_queue_find_custom(&conn->secondary_list,
689                  pkt, (GCompareFunc)HandlePacket);
690 
691         if (result) {
692             colo_release_primary_pkt(s, pkt);
693             g_queue_remove(&conn->secondary_list, result->data);
694         } else {
695             /*
696              * If one packet arrive late, the secondary_list or
697              * primary_list will be empty, so we can't compare it
698              * until next comparison. If the packets in the list are
699              * timeout, it will trigger a checkpoint request.
700              */
701             trace_colo_compare_main("packet different");
702             g_queue_push_head(&conn->primary_list, pkt);
703 
704             colo_compare_inconsistency_notify(s);
705             break;
706         }
707     }
708 }
709 
710 /*
711  * Called from the compare thread on the primary
712  * for compare packet with secondary list of the
713  * specified connection when a new packet was
714  * queued to it.
715  */
716 static void colo_compare_connection(void *opaque, void *user_data)
717 {
718     CompareState *s = user_data;
719     Connection *conn = opaque;
720 
721     switch (conn->ip_proto) {
722     case IPPROTO_TCP:
723         colo_compare_tcp(s, conn);
724         break;
725     case IPPROTO_UDP:
726         colo_compare_packet(s, conn, colo_packet_compare_udp);
727         break;
728     case IPPROTO_ICMP:
729         colo_compare_packet(s, conn, colo_packet_compare_icmp);
730         break;
731     default:
732         colo_compare_packet(s, conn, colo_packet_compare_other);
733         break;
734     }
735 }
736 
737 static void coroutine_fn _compare_chr_send(void *opaque)
738 {
739     SendCo *sendco = opaque;
740     CompareState *s = sendco->s;
741     int ret = 0;
742 
743     while (!g_queue_is_empty(&sendco->send_list)) {
744         SendEntry *entry = g_queue_pop_tail(&sendco->send_list);
745         uint32_t len = htonl(entry->size);
746 
747         ret = qemu_chr_fe_write_all(sendco->chr, (uint8_t *)&len, sizeof(len));
748 
749         if (ret != sizeof(len)) {
750             g_free(entry->buf);
751             g_slice_free(SendEntry, entry);
752             goto err;
753         }
754 
755         if (!sendco->notify_remote_frame && s->vnet_hdr) {
756             /*
757              * We send vnet header len make other module(like filter-redirector)
758              * know how to parse net packet correctly.
759              */
760             len = htonl(entry->vnet_hdr_len);
761 
762             ret = qemu_chr_fe_write_all(sendco->chr,
763                                         (uint8_t *)&len,
764                                         sizeof(len));
765 
766             if (ret != sizeof(len)) {
767                 g_free(entry->buf);
768                 g_slice_free(SendEntry, entry);
769                 goto err;
770             }
771         }
772 
773         ret = qemu_chr_fe_write_all(sendco->chr,
774                                     (uint8_t *)entry->buf,
775                                     entry->size);
776 
777         if (ret != entry->size) {
778             g_free(entry->buf);
779             g_slice_free(SendEntry, entry);
780             goto err;
781         }
782 
783         g_free(entry->buf);
784         g_slice_free(SendEntry, entry);
785     }
786 
787     sendco->ret = 0;
788     goto out;
789 
790 err:
791     while (!g_queue_is_empty(&sendco->send_list)) {
792         SendEntry *entry = g_queue_pop_tail(&sendco->send_list);
793         g_free(entry->buf);
794         g_slice_free(SendEntry, entry);
795     }
796     sendco->ret = ret < 0 ? ret : -EIO;
797 out:
798     sendco->co = NULL;
799     sendco->done = true;
800     aio_wait_kick();
801 }
802 
803 static int compare_chr_send(CompareState *s,
804                             uint8_t *buf,
805                             uint32_t size,
806                             uint32_t vnet_hdr_len,
807                             bool notify_remote_frame,
808                             bool zero_copy)
809 {
810     SendCo *sendco;
811     SendEntry *entry;
812 
813     if (notify_remote_frame) {
814         sendco = &s->notify_sendco;
815     } else {
816         sendco = &s->out_sendco;
817     }
818 
819     if (!size) {
820         return 0;
821     }
822 
823     entry = g_slice_new(SendEntry);
824     entry->size = size;
825     entry->vnet_hdr_len = vnet_hdr_len;
826     if (zero_copy) {
827         entry->buf = buf;
828     } else {
829         entry->buf = g_malloc(size);
830         memcpy(entry->buf, buf, size);
831     }
832     g_queue_push_head(&sendco->send_list, entry);
833 
834     if (sendco->done) {
835         sendco->co = qemu_coroutine_create(_compare_chr_send, sendco);
836         sendco->done = false;
837         qemu_coroutine_enter(sendco->co);
838         if (sendco->done) {
839             /* report early errors */
840             return sendco->ret;
841         }
842     }
843 
844     /* assume success */
845     return 0;
846 }
847 
848 static int compare_chr_can_read(void *opaque)
849 {
850     return COMPARE_READ_LEN_MAX;
851 }
852 
853 /*
854  * Called from the main thread on the primary for packets
855  * arriving over the socket from the primary.
856  */
857 static void compare_pri_chr_in(void *opaque, const uint8_t *buf, int size)
858 {
859     CompareState *s = COLO_COMPARE(opaque);
860     int ret;
861 
862     ret = net_fill_rstate(&s->pri_rs, buf, size);
863     if (ret == -1) {
864         qemu_chr_fe_set_handlers(&s->chr_pri_in, NULL, NULL, NULL, NULL,
865                                  NULL, NULL, true);
866         error_report("colo-compare primary_in error");
867     }
868 }
869 
870 /*
871  * Called from the main thread on the primary for packets
872  * arriving over the socket from the secondary.
873  */
874 static void compare_sec_chr_in(void *opaque, const uint8_t *buf, int size)
875 {
876     CompareState *s = COLO_COMPARE(opaque);
877     int ret;
878 
879     ret = net_fill_rstate(&s->sec_rs, buf, size);
880     if (ret == -1) {
881         qemu_chr_fe_set_handlers(&s->chr_sec_in, NULL, NULL, NULL, NULL,
882                                  NULL, NULL, true);
883         error_report("colo-compare secondary_in error");
884     }
885 }
886 
887 static void compare_notify_chr(void *opaque, const uint8_t *buf, int size)
888 {
889     CompareState *s = COLO_COMPARE(opaque);
890     int ret;
891 
892     ret = net_fill_rstate(&s->notify_rs, buf, size);
893     if (ret == -1) {
894         qemu_chr_fe_set_handlers(&s->chr_notify_dev, NULL, NULL, NULL, NULL,
895                                  NULL, NULL, true);
896         error_report("colo-compare notify_dev error");
897     }
898 }
899 
900 /*
901  * Check old packet regularly so it can watch for any packets
902  * that the secondary hasn't produced equivalents of.
903  */
904 static void check_old_packet_regular(void *opaque)
905 {
906     CompareState *s = opaque;
907 
908     /* if have old packet we will notify checkpoint */
909     colo_old_packet_check(s);
910     timer_mod(s->packet_check_timer, qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) +
911               s->expired_scan_cycle);
912 }
913 
914 /* Public API, Used for COLO frame to notify compare event */
915 void colo_notify_compares_event(void *opaque, int event, Error **errp)
916 {
917     CompareState *s;
918     qemu_mutex_lock(&colo_compare_mutex);
919 
920     if (!colo_compare_active) {
921         qemu_mutex_unlock(&colo_compare_mutex);
922         return;
923     }
924 
925     qemu_mutex_lock(&event_mtx);
926     QTAILQ_FOREACH(s, &net_compares, next) {
927         s->event = event;
928         qemu_bh_schedule(s->event_bh);
929         event_unhandled_count++;
930     }
931     /* Wait all compare threads to finish handling this event */
932     while (event_unhandled_count > 0) {
933         qemu_cond_wait(&event_complete_cond, &event_mtx);
934     }
935 
936     qemu_mutex_unlock(&event_mtx);
937     qemu_mutex_unlock(&colo_compare_mutex);
938 }
939 
940 static void colo_compare_timer_init(CompareState *s)
941 {
942     AioContext *ctx = iothread_get_aio_context(s->iothread);
943 
944     s->packet_check_timer = aio_timer_new(ctx, QEMU_CLOCK_VIRTUAL,
945                                 SCALE_MS, check_old_packet_regular,
946                                 s);
947     timer_mod(s->packet_check_timer, qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) +
948               s->expired_scan_cycle);
949 }
950 
951 static void colo_compare_timer_del(CompareState *s)
952 {
953     if (s->packet_check_timer) {
954         timer_del(s->packet_check_timer);
955         timer_free(s->packet_check_timer);
956         s->packet_check_timer = NULL;
957     }
958  }
959 
960 static void colo_flush_packets(void *opaque, void *user_data);
961 
962 static void colo_compare_handle_event(void *opaque)
963 {
964     CompareState *s = opaque;
965 
966     switch (s->event) {
967     case COLO_EVENT_CHECKPOINT:
968         g_queue_foreach(&s->conn_list, colo_flush_packets, s);
969         break;
970     case COLO_EVENT_FAILOVER:
971         break;
972     default:
973         break;
974     }
975 
976     qemu_mutex_lock(&event_mtx);
977     assert(event_unhandled_count > 0);
978     event_unhandled_count--;
979     qemu_cond_broadcast(&event_complete_cond);
980     qemu_mutex_unlock(&event_mtx);
981 }
982 
983 static void colo_compare_iothread(CompareState *s)
984 {
985     AioContext *ctx = iothread_get_aio_context(s->iothread);
986     object_ref(OBJECT(s->iothread));
987     s->worker_context = iothread_get_g_main_context(s->iothread);
988 
989     qemu_chr_fe_set_handlers(&s->chr_pri_in, compare_chr_can_read,
990                              compare_pri_chr_in, NULL, NULL,
991                              s, s->worker_context, true);
992     qemu_chr_fe_set_handlers(&s->chr_sec_in, compare_chr_can_read,
993                              compare_sec_chr_in, NULL, NULL,
994                              s, s->worker_context, true);
995     if (s->notify_dev) {
996         qemu_chr_fe_set_handlers(&s->chr_notify_dev, compare_chr_can_read,
997                                  compare_notify_chr, NULL, NULL,
998                                  s, s->worker_context, true);
999     }
1000 
1001     colo_compare_timer_init(s);
1002     s->event_bh = aio_bh_new(ctx, colo_compare_handle_event, s);
1003 }
1004 
1005 static char *compare_get_pri_indev(Object *obj, Error **errp)
1006 {
1007     CompareState *s = COLO_COMPARE(obj);
1008 
1009     return g_strdup(s->pri_indev);
1010 }
1011 
1012 static void compare_set_pri_indev(Object *obj, const char *value, Error **errp)
1013 {
1014     CompareState *s = COLO_COMPARE(obj);
1015 
1016     g_free(s->pri_indev);
1017     s->pri_indev = g_strdup(value);
1018 }
1019 
1020 static char *compare_get_sec_indev(Object *obj, Error **errp)
1021 {
1022     CompareState *s = COLO_COMPARE(obj);
1023 
1024     return g_strdup(s->sec_indev);
1025 }
1026 
1027 static void compare_set_sec_indev(Object *obj, const char *value, Error **errp)
1028 {
1029     CompareState *s = COLO_COMPARE(obj);
1030 
1031     g_free(s->sec_indev);
1032     s->sec_indev = g_strdup(value);
1033 }
1034 
1035 static char *compare_get_outdev(Object *obj, Error **errp)
1036 {
1037     CompareState *s = COLO_COMPARE(obj);
1038 
1039     return g_strdup(s->outdev);
1040 }
1041 
1042 static void compare_set_outdev(Object *obj, const char *value, Error **errp)
1043 {
1044     CompareState *s = COLO_COMPARE(obj);
1045 
1046     g_free(s->outdev);
1047     s->outdev = g_strdup(value);
1048 }
1049 
1050 static bool compare_get_vnet_hdr(Object *obj, Error **errp)
1051 {
1052     CompareState *s = COLO_COMPARE(obj);
1053 
1054     return s->vnet_hdr;
1055 }
1056 
1057 static void compare_set_vnet_hdr(Object *obj,
1058                                  bool value,
1059                                  Error **errp)
1060 {
1061     CompareState *s = COLO_COMPARE(obj);
1062 
1063     s->vnet_hdr = value;
1064 }
1065 
1066 static char *compare_get_notify_dev(Object *obj, Error **errp)
1067 {
1068     CompareState *s = COLO_COMPARE(obj);
1069 
1070     return g_strdup(s->notify_dev);
1071 }
1072 
1073 static void compare_set_notify_dev(Object *obj, const char *value, Error **errp)
1074 {
1075     CompareState *s = COLO_COMPARE(obj);
1076 
1077     g_free(s->notify_dev);
1078     s->notify_dev = g_strdup(value);
1079 }
1080 
1081 static void compare_get_timeout(Object *obj, Visitor *v,
1082                                 const char *name, void *opaque,
1083                                 Error **errp)
1084 {
1085     CompareState *s = COLO_COMPARE(obj);
1086     uint32_t value = s->compare_timeout;
1087 
1088     visit_type_uint32(v, name, &value, errp);
1089 }
1090 
1091 static void compare_set_timeout(Object *obj, Visitor *v,
1092                                 const char *name, void *opaque,
1093                                 Error **errp)
1094 {
1095     CompareState *s = COLO_COMPARE(obj);
1096     Error *local_err = NULL;
1097     uint32_t value;
1098 
1099     visit_type_uint32(v, name, &value, &local_err);
1100     if (local_err) {
1101         goto out;
1102     }
1103     if (!value) {
1104         error_setg(&local_err, "Property '%s.%s' requires a positive value",
1105                    object_get_typename(obj), name);
1106         goto out;
1107     }
1108     s->compare_timeout = value;
1109 
1110 out:
1111     error_propagate(errp, local_err);
1112 }
1113 
1114 static void compare_get_expired_scan_cycle(Object *obj, Visitor *v,
1115                                            const char *name, void *opaque,
1116                                            Error **errp)
1117 {
1118     CompareState *s = COLO_COMPARE(obj);
1119     uint32_t value = s->expired_scan_cycle;
1120 
1121     visit_type_uint32(v, name, &value, errp);
1122 }
1123 
1124 static void compare_set_expired_scan_cycle(Object *obj, Visitor *v,
1125                                            const char *name, void *opaque,
1126                                            Error **errp)
1127 {
1128     CompareState *s = COLO_COMPARE(obj);
1129     Error *local_err = NULL;
1130     uint32_t value;
1131 
1132     visit_type_uint32(v, name, &value, &local_err);
1133     if (local_err) {
1134         goto out;
1135     }
1136     if (!value) {
1137         error_setg(&local_err, "Property '%s.%s' requires a positive value",
1138                    object_get_typename(obj), name);
1139         goto out;
1140     }
1141     s->expired_scan_cycle = value;
1142 
1143 out:
1144     error_propagate(errp, local_err);
1145 }
1146 
1147 static void compare_pri_rs_finalize(SocketReadState *pri_rs)
1148 {
1149     CompareState *s = container_of(pri_rs, CompareState, pri_rs);
1150     Connection *conn = NULL;
1151 
1152     if (packet_enqueue(s, PRIMARY_IN, &conn)) {
1153         trace_colo_compare_main("primary: unsupported packet in");
1154         compare_chr_send(s,
1155                          pri_rs->buf,
1156                          pri_rs->packet_len,
1157                          pri_rs->vnet_hdr_len,
1158                          false,
1159                          false);
1160     } else {
1161         /* compare packet in the specified connection */
1162         colo_compare_connection(conn, s);
1163     }
1164 }
1165 
1166 static void compare_sec_rs_finalize(SocketReadState *sec_rs)
1167 {
1168     CompareState *s = container_of(sec_rs, CompareState, sec_rs);
1169     Connection *conn = NULL;
1170 
1171     if (packet_enqueue(s, SECONDARY_IN, &conn)) {
1172         trace_colo_compare_main("secondary: unsupported packet in");
1173     } else {
1174         /* compare packet in the specified connection */
1175         colo_compare_connection(conn, s);
1176     }
1177 }
1178 
1179 static void compare_notify_rs_finalize(SocketReadState *notify_rs)
1180 {
1181     CompareState *s = container_of(notify_rs, CompareState, notify_rs);
1182 
1183     const char msg[] = "COLO_COMPARE_GET_XEN_INIT";
1184     int ret;
1185 
1186     if (packet_matches_str("COLO_USERSPACE_PROXY_INIT",
1187                            notify_rs->buf,
1188                            notify_rs->packet_len)) {
1189         ret = compare_chr_send(s, (uint8_t *)msg, strlen(msg), 0, true, false);
1190         if (ret < 0) {
1191             error_report("Notify Xen COLO-frame INIT failed");
1192         }
1193     } else if (packet_matches_str("COLO_CHECKPOINT",
1194                                   notify_rs->buf,
1195                                   notify_rs->packet_len)) {
1196         /* colo-compare do checkpoint, flush pri packet and remove sec packet */
1197         g_queue_foreach(&s->conn_list, colo_flush_packets, s);
1198     } else {
1199         error_report("COLO compare got unsupported instruction");
1200     }
1201 }
1202 
1203 /*
1204  * Return 0 is success.
1205  * Return 1 is failed.
1206  */
1207 static int find_and_check_chardev(Chardev **chr,
1208                                   char *chr_name,
1209                                   Error **errp)
1210 {
1211     *chr = qemu_chr_find(chr_name);
1212     if (*chr == NULL) {
1213         error_setg(errp, "Device '%s' not found",
1214                    chr_name);
1215         return 1;
1216     }
1217 
1218     if (!qemu_chr_has_feature(*chr, QEMU_CHAR_FEATURE_RECONNECTABLE)) {
1219         error_setg(errp, "chardev \"%s\" is not reconnectable",
1220                    chr_name);
1221         return 1;
1222     }
1223 
1224     if (!qemu_chr_has_feature(*chr, QEMU_CHAR_FEATURE_GCONTEXT)) {
1225         error_setg(errp, "chardev \"%s\" cannot switch context",
1226                    chr_name);
1227         return 1;
1228     }
1229 
1230     return 0;
1231 }
1232 
1233 /*
1234  * Called from the main thread on the primary
1235  * to setup colo-compare.
1236  */
1237 static void colo_compare_complete(UserCreatable *uc, Error **errp)
1238 {
1239     CompareState *s = COLO_COMPARE(uc);
1240     Chardev *chr;
1241 
1242     if (!s->pri_indev || !s->sec_indev || !s->outdev || !s->iothread) {
1243         error_setg(errp, "colo compare needs 'primary_in' ,"
1244                    "'secondary_in','outdev','iothread' property set");
1245         return;
1246     } else if (!strcmp(s->pri_indev, s->outdev) ||
1247                !strcmp(s->sec_indev, s->outdev) ||
1248                !strcmp(s->pri_indev, s->sec_indev)) {
1249         error_setg(errp, "'indev' and 'outdev' could not be same "
1250                    "for compare module");
1251         return;
1252     }
1253 
1254     if (!s->compare_timeout) {
1255         /* Set default value to 3000 MS */
1256         s->compare_timeout = DEFAULT_TIME_OUT_MS;
1257     }
1258 
1259     if (!s->expired_scan_cycle) {
1260         /* Set default value to 3000 MS */
1261         s->expired_scan_cycle = REGULAR_PACKET_CHECK_MS;
1262     }
1263 
1264     if (find_and_check_chardev(&chr, s->pri_indev, errp) ||
1265         !qemu_chr_fe_init(&s->chr_pri_in, chr, errp)) {
1266         return;
1267     }
1268 
1269     if (find_and_check_chardev(&chr, s->sec_indev, errp) ||
1270         !qemu_chr_fe_init(&s->chr_sec_in, chr, errp)) {
1271         return;
1272     }
1273 
1274     if (find_and_check_chardev(&chr, s->outdev, errp) ||
1275         !qemu_chr_fe_init(&s->chr_out, chr, errp)) {
1276         return;
1277     }
1278 
1279     net_socket_rs_init(&s->pri_rs, compare_pri_rs_finalize, s->vnet_hdr);
1280     net_socket_rs_init(&s->sec_rs, compare_sec_rs_finalize, s->vnet_hdr);
1281 
1282     /* Try to enable remote notify chardev, currently just for Xen COLO */
1283     if (s->notify_dev) {
1284         if (find_and_check_chardev(&chr, s->notify_dev, errp) ||
1285             !qemu_chr_fe_init(&s->chr_notify_dev, chr, errp)) {
1286             return;
1287         }
1288 
1289         net_socket_rs_init(&s->notify_rs, compare_notify_rs_finalize,
1290                            s->vnet_hdr);
1291     }
1292 
1293     s->out_sendco.s = s;
1294     s->out_sendco.chr = &s->chr_out;
1295     s->out_sendco.notify_remote_frame = false;
1296     s->out_sendco.done = true;
1297     g_queue_init(&s->out_sendco.send_list);
1298 
1299     if (s->notify_dev) {
1300         s->notify_sendco.s = s;
1301         s->notify_sendco.chr = &s->chr_notify_dev;
1302         s->notify_sendco.notify_remote_frame = true;
1303         s->notify_sendco.done = true;
1304         g_queue_init(&s->notify_sendco.send_list);
1305     }
1306 
1307     g_queue_init(&s->conn_list);
1308 
1309     s->connection_track_table = g_hash_table_new_full(connection_key_hash,
1310                                                       connection_key_equal,
1311                                                       g_free,
1312                                                       connection_destroy);
1313 
1314     colo_compare_iothread(s);
1315 
1316     qemu_mutex_lock(&colo_compare_mutex);
1317     if (!colo_compare_active) {
1318         qemu_mutex_init(&event_mtx);
1319         qemu_cond_init(&event_complete_cond);
1320         colo_compare_active = true;
1321     }
1322     QTAILQ_INSERT_TAIL(&net_compares, s, next);
1323     qemu_mutex_unlock(&colo_compare_mutex);
1324 
1325     return;
1326 }
1327 
1328 static void colo_flush_packets(void *opaque, void *user_data)
1329 {
1330     CompareState *s = user_data;
1331     Connection *conn = opaque;
1332     Packet *pkt = NULL;
1333 
1334     while (!g_queue_is_empty(&conn->primary_list)) {
1335         pkt = g_queue_pop_head(&conn->primary_list);
1336         compare_chr_send(s,
1337                          pkt->data,
1338                          pkt->size,
1339                          pkt->vnet_hdr_len,
1340                          false,
1341                          true);
1342         packet_destroy_partial(pkt, NULL);
1343     }
1344     while (!g_queue_is_empty(&conn->secondary_list)) {
1345         pkt = g_queue_pop_head(&conn->secondary_list);
1346         packet_destroy(pkt, NULL);
1347     }
1348 }
1349 
1350 static void colo_compare_class_init(ObjectClass *oc, void *data)
1351 {
1352     UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);
1353 
1354     ucc->complete = colo_compare_complete;
1355 }
1356 
1357 static void colo_compare_init(Object *obj)
1358 {
1359     CompareState *s = COLO_COMPARE(obj);
1360 
1361     object_property_add_str(obj, "primary_in",
1362                             compare_get_pri_indev, compare_set_pri_indev);
1363     object_property_add_str(obj, "secondary_in",
1364                             compare_get_sec_indev, compare_set_sec_indev);
1365     object_property_add_str(obj, "outdev",
1366                             compare_get_outdev, compare_set_outdev);
1367     object_property_add_link(obj, "iothread", TYPE_IOTHREAD,
1368                             (Object **)&s->iothread,
1369                             object_property_allow_set_link,
1370                             OBJ_PROP_LINK_STRONG);
1371     /* This parameter just for Xen COLO */
1372     object_property_add_str(obj, "notify_dev",
1373                             compare_get_notify_dev, compare_set_notify_dev);
1374 
1375     object_property_add(obj, "compare_timeout", "uint32",
1376                         compare_get_timeout,
1377                         compare_set_timeout, NULL, NULL);
1378 
1379     object_property_add(obj, "expired_scan_cycle", "uint32",
1380                         compare_get_expired_scan_cycle,
1381                         compare_set_expired_scan_cycle, NULL, NULL);
1382 
1383     s->vnet_hdr = false;
1384     object_property_add_bool(obj, "vnet_hdr_support", compare_get_vnet_hdr,
1385                              compare_set_vnet_hdr);
1386 }
1387 
1388 static void colo_compare_finalize(Object *obj)
1389 {
1390     CompareState *s = COLO_COMPARE(obj);
1391     CompareState *tmp = NULL;
1392 
1393     qemu_mutex_lock(&colo_compare_mutex);
1394     QTAILQ_FOREACH(tmp, &net_compares, next) {
1395         if (tmp == s) {
1396             QTAILQ_REMOVE(&net_compares, s, next);
1397             break;
1398         }
1399     }
1400     if (QTAILQ_EMPTY(&net_compares)) {
1401         colo_compare_active = false;
1402         qemu_mutex_destroy(&event_mtx);
1403         qemu_cond_destroy(&event_complete_cond);
1404     }
1405     qemu_mutex_unlock(&colo_compare_mutex);
1406 
1407     qemu_chr_fe_deinit(&s->chr_pri_in, false);
1408     qemu_chr_fe_deinit(&s->chr_sec_in, false);
1409     qemu_chr_fe_deinit(&s->chr_out, false);
1410     if (s->notify_dev) {
1411         qemu_chr_fe_deinit(&s->chr_notify_dev, false);
1412     }
1413 
1414     if (s->iothread) {
1415         colo_compare_timer_del(s);
1416     }
1417 
1418     qemu_bh_delete(s->event_bh);
1419 
1420     AioContext *ctx = iothread_get_aio_context(s->iothread);
1421     aio_context_acquire(ctx);
1422     AIO_WAIT_WHILE(ctx, !s->out_sendco.done);
1423     if (s->notify_dev) {
1424         AIO_WAIT_WHILE(ctx, !s->notify_sendco.done);
1425     }
1426     aio_context_release(ctx);
1427 
1428     /* Release all unhandled packets after compare thead exited */
1429     g_queue_foreach(&s->conn_list, colo_flush_packets, s);
1430     AIO_WAIT_WHILE(NULL, !s->out_sendco.done);
1431 
1432     g_queue_clear(&s->conn_list);
1433     g_queue_clear(&s->out_sendco.send_list);
1434     if (s->notify_dev) {
1435         g_queue_clear(&s->notify_sendco.send_list);
1436     }
1437 
1438     if (s->connection_track_table) {
1439         g_hash_table_destroy(s->connection_track_table);
1440     }
1441 
1442     if (s->iothread) {
1443         object_unref(OBJECT(s->iothread));
1444     }
1445 
1446     g_free(s->pri_indev);
1447     g_free(s->sec_indev);
1448     g_free(s->outdev);
1449     g_free(s->notify_dev);
1450 }
1451 
1452 static void __attribute__((__constructor__)) colo_compare_init_globals(void)
1453 {
1454     colo_compare_active = false;
1455     qemu_mutex_init(&colo_compare_mutex);
1456 }
1457 
1458 static const TypeInfo colo_compare_info = {
1459     .name = TYPE_COLO_COMPARE,
1460     .parent = TYPE_OBJECT,
1461     .instance_size = sizeof(CompareState),
1462     .instance_init = colo_compare_init,
1463     .instance_finalize = colo_compare_finalize,
1464     .class_size = sizeof(CompareClass),
1465     .class_init = colo_compare_class_init,
1466     .interfaces = (InterfaceInfo[]) {
1467         { TYPE_USER_CREATABLE },
1468         { }
1469     }
1470 };
1471 
1472 static void register_types(void)
1473 {
1474     type_register_static(&colo_compare_info);
1475 }
1476 
1477 type_init(register_types);
1478