xref: /openbmc/qemu/net/colo-compare.c (revision 10eb3721)
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 "util.h"
32 
33 #include "block/aio-wait.h"
34 #include "qemu/coroutine.h"
35 
36 #define TYPE_COLO_COMPARE "colo-compare"
37 typedef struct CompareState CompareState;
38 DECLARE_INSTANCE_CHECKER(CompareState, COLO_COMPARE,
39                          TYPE_COLO_COMPARE)
40 
41 static QTAILQ_HEAD(, CompareState) net_compares =
42        QTAILQ_HEAD_INITIALIZER(net_compares);
43 
44 static NotifierList colo_compare_notifiers =
45     NOTIFIER_LIST_INITIALIZER(colo_compare_notifiers);
46 
47 #define COMPARE_READ_LEN_MAX NET_BUFSIZE
48 #define MAX_QUEUE_SIZE 1024
49 
50 #define COLO_COMPARE_FREE_PRIMARY     0x01
51 #define COLO_COMPARE_FREE_SECONDARY   0x02
52 
53 #define REGULAR_PACKET_CHECK_MS 1000
54 #define DEFAULT_TIME_OUT_MS 3000
55 
56 /* #define DEBUG_COLO_PACKETS */
57 
58 static QemuMutex colo_compare_mutex;
59 static bool colo_compare_active;
60 static QemuMutex event_mtx;
61 static QemuCond event_complete_cond;
62 static int event_unhandled_count;
63 static uint32_t max_queue_size;
64 
65 /*
66  *  + CompareState ++
67  *  |               |
68  *  +---------------+   +---------------+         +---------------+
69  *  |   conn list   + - >      conn     + ------- >      conn     + -- > ......
70  *  +---------------+   +---------------+         +---------------+
71  *  |               |     |           |             |          |
72  *  +---------------+ +---v----+  +---v----+    +---v----+ +---v----+
73  *                    |primary |  |secondary    |primary | |secondary
74  *                    |packet  |  |packet  +    |packet  | |packet  +
75  *                    +--------+  +--------+    +--------+ +--------+
76  *                        |           |             |          |
77  *                    +---v----+  +---v----+    +---v----+ +---v----+
78  *                    |primary |  |secondary    |primary | |secondary
79  *                    |packet  |  |packet  +    |packet  | |packet  +
80  *                    +--------+  +--------+    +--------+ +--------+
81  *                        |           |             |          |
82  *                    +---v----+  +---v----+    +---v----+ +---v----+
83  *                    |primary |  |secondary    |primary | |secondary
84  *                    |packet  |  |packet  +    |packet  | |packet  +
85  *                    +--------+  +--------+    +--------+ +--------+
86  */
87 
88 typedef struct SendCo {
89     Coroutine *co;
90     struct CompareState *s;
91     CharBackend *chr;
92     GQueue send_list;
93     bool notify_remote_frame;
94     bool done;
95     int ret;
96 } SendCo;
97 
98 typedef struct SendEntry {
99     uint32_t size;
100     uint32_t vnet_hdr_len;
101     uint8_t *buf;
102 } SendEntry;
103 
104 struct CompareState {
105     Object parent;
106 
107     char *pri_indev;
108     char *sec_indev;
109     char *outdev;
110     char *notify_dev;
111     CharBackend chr_pri_in;
112     CharBackend chr_sec_in;
113     CharBackend chr_out;
114     CharBackend chr_notify_dev;
115     SocketReadState pri_rs;
116     SocketReadState sec_rs;
117     SocketReadState notify_rs;
118     SendCo out_sendco;
119     SendCo notify_sendco;
120     bool vnet_hdr;
121     uint64_t compare_timeout;
122     uint32_t expired_scan_cycle;
123 
124     /*
125      * Record the connection that through the NIC
126      * Element type: Connection
127      */
128     GQueue conn_list;
129     /* Record the connection without repetition */
130     GHashTable *connection_track_table;
131 
132     IOThread *iothread;
133     GMainContext *worker_context;
134     QEMUTimer *packet_check_timer;
135 
136     QEMUBH *event_bh;
137     enum colo_event event;
138 
139     QTAILQ_ENTRY(CompareState) next;
140 };
141 
142 typedef struct CompareClass {
143     ObjectClass parent_class;
144 } CompareClass;
145 
146 enum {
147     PRIMARY_IN = 0,
148     SECONDARY_IN,
149 };
150 
151 static const char *colo_mode[] = {
152     [PRIMARY_IN] = "primary",
153     [SECONDARY_IN] = "secondary",
154 };
155 
156 static int compare_chr_send(CompareState *s,
157                             uint8_t *buf,
158                             uint32_t size,
159                             uint32_t vnet_hdr_len,
160                             bool notify_remote_frame,
161                             bool zero_copy);
162 
163 static bool packet_matches_str(const char *str,
164                                const uint8_t *buf,
165                                uint32_t packet_len)
166 {
167     if (packet_len != strlen(str)) {
168         return false;
169     }
170 
171     return !memcmp(str, buf, packet_len);
172 }
173 
174 static void notify_remote_frame(CompareState *s)
175 {
176     char msg[] = "DO_CHECKPOINT";
177     int ret = 0;
178 
179     ret = compare_chr_send(s, (uint8_t *)msg, strlen(msg), 0, true, false);
180     if (ret < 0) {
181         error_report("Notify Xen COLO-frame failed");
182     }
183 }
184 
185 static void colo_compare_inconsistency_notify(CompareState *s)
186 {
187     if (s->notify_dev) {
188         notify_remote_frame(s);
189     } else {
190         notifier_list_notify(&colo_compare_notifiers,
191                              NULL);
192     }
193 }
194 
195 /* Use restricted to colo_insert_packet() */
196 static gint seq_sorter(Packet *a, Packet *b, gpointer data)
197 {
198     return b->tcp_seq - a->tcp_seq;
199 }
200 
201 static void fill_pkt_tcp_info(void *data, uint32_t *max_ack)
202 {
203     Packet *pkt = data;
204     struct tcp_hdr *tcphd;
205 
206     tcphd = (struct tcp_hdr *)pkt->transport_header;
207 
208     pkt->tcp_seq = ntohl(tcphd->th_seq);
209     pkt->tcp_ack = ntohl(tcphd->th_ack);
210     /* Need to consider ACK will bigger than uint32_t MAX */
211     *max_ack = pkt->tcp_ack - *max_ack > 0 ? pkt->tcp_ack : *max_ack;
212     pkt->header_size = pkt->transport_header - (uint8_t *)pkt->data
213                        + (tcphd->th_off << 2);
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, false);
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_IP_INFO)) {
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 = MIN(conn->pack, conn->sack);
416 
417 pri:
418     if (g_queue_is_empty(&conn->primary_list)) {
419         return;
420     }
421     ppkt = g_queue_pop_tail(&conn->primary_list);
422 sec:
423     if (g_queue_is_empty(&conn->secondary_list)) {
424         g_queue_push_tail(&conn->primary_list, ppkt);
425         return;
426     }
427     spkt = g_queue_pop_tail(&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_tail(&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_tail(&conn->secondary_list, spkt);
478             goto pri;
479         } else if (mark == COLO_COMPARE_FREE_SECONDARY) {
480             conn->compare_seq = spkt->seq_end;
481             packet_destroy(spkt, NULL);
482             goto sec;
483         } else if (mark == (COLO_COMPARE_FREE_PRIMARY | COLO_COMPARE_FREE_SECONDARY)) {
484             conn->compare_seq = ppkt->seq_end;
485             colo_release_primary_pkt(s, ppkt);
486             packet_destroy(spkt, NULL);
487             goto pri;
488         }
489     } else {
490         g_queue_push_tail(&conn->primary_list, ppkt);
491         g_queue_push_tail(&conn->secondary_list, spkt);
492 
493 #ifdef DEBUG_COLO_PACKETS
494         qemu_hexdump(stderr, "colo-compare ppkt", ppkt->data, ppkt->size);
495         qemu_hexdump(stderr, "colo-compare spkt", spkt->data, spkt->size);
496 #endif
497 
498         colo_compare_inconsistency_notify(s);
499     }
500 }
501 
502 
503 /*
504  * Called from the compare thread on the primary
505  * for compare udp packet
506  */
507 static int colo_packet_compare_udp(Packet *spkt, Packet *ppkt)
508 {
509     uint16_t network_header_length = ppkt->ip->ip_hl << 2;
510     uint16_t offset = network_header_length + ETH_HLEN + ppkt->vnet_hdr_len;
511 
512     trace_colo_compare_main("compare udp");
513 
514     /*
515      * Because of ppkt and spkt are both in the same connection,
516      * The ppkt's src ip, dst ip, src port, dst port, ip_proto all are
517      * same with spkt. In addition, IP header's Identification is a random
518      * field, we can handle it in IP fragmentation function later.
519      * COLO just concern the response net packet payload from primary guest
520      * and secondary guest are same or not, So we ignored all IP header include
521      * other field like TOS,TTL,IP Checksum. we only need to compare
522      * the ip payload here.
523      */
524     if (ppkt->size != spkt->size) {
525         trace_colo_compare_main("UDP: payload size of packets are different");
526         return -1;
527     }
528     if (colo_compare_packet_payload(ppkt, spkt, offset, offset,
529                                     ppkt->size - offset)) {
530         trace_colo_compare_udp_miscompare("primary pkt size", ppkt->size);
531         trace_colo_compare_udp_miscompare("Secondary pkt size", spkt->size);
532 #ifdef DEBUG_COLO_PACKETS
533         qemu_hexdump(stderr, "colo-compare pri pkt", ppkt->data, ppkt->size);
534         qemu_hexdump(stderr, "colo-compare sec pkt", spkt->data, spkt->size);
535 #endif
536         return -1;
537     } else {
538         return 0;
539     }
540 }
541 
542 /*
543  * Called from the compare thread on the primary
544  * for compare icmp packet
545  */
546 static int colo_packet_compare_icmp(Packet *spkt, Packet *ppkt)
547 {
548     uint16_t network_header_length = ppkt->ip->ip_hl << 2;
549     uint16_t offset = network_header_length + ETH_HLEN + ppkt->vnet_hdr_len;
550 
551     trace_colo_compare_main("compare icmp");
552 
553     /*
554      * Because of ppkt and spkt are both in the same connection,
555      * The ppkt's src ip, dst ip, src port, dst port, ip_proto all are
556      * same with spkt. In addition, IP header's Identification is a random
557      * field, we can handle it in IP fragmentation function later.
558      * COLO just concern the response net packet payload from primary guest
559      * and secondary guest are same or not, So we ignored all IP header include
560      * other field like TOS,TTL,IP Checksum. we only need to compare
561      * the ip payload here.
562      */
563     if (ppkt->size != spkt->size) {
564         trace_colo_compare_main("ICMP: payload size of packets are different");
565         return -1;
566     }
567     if (colo_compare_packet_payload(ppkt, spkt, offset, offset,
568                                     ppkt->size - offset)) {
569         trace_colo_compare_icmp_miscompare("primary pkt size",
570                                            ppkt->size);
571         trace_colo_compare_icmp_miscompare("Secondary pkt size",
572                                            spkt->size);
573 #ifdef DEBUG_COLO_PACKETS
574         qemu_hexdump(stderr, "colo-compare pri pkt", ppkt->data, ppkt->size);
575         qemu_hexdump(stderr, "colo-compare sec pkt", spkt->data, spkt->size);
576 #endif
577         return -1;
578     } else {
579         return 0;
580     }
581 }
582 
583 /*
584  * Called from the compare thread on the primary
585  * for compare other packet
586  */
587 static int colo_packet_compare_other(Packet *spkt, Packet *ppkt)
588 {
589     uint16_t offset = ppkt->vnet_hdr_len;
590 
591     trace_colo_compare_main("compare other");
592     if (ppkt->size != spkt->size) {
593         trace_colo_compare_main("Other: payload size of packets are different");
594         return -1;
595     }
596     return colo_compare_packet_payload(ppkt, spkt, offset, offset,
597                                        ppkt->size - offset);
598 }
599 
600 static int colo_old_packet_check_one(Packet *pkt, int64_t *check_time)
601 {
602     int64_t now = qemu_clock_get_ms(QEMU_CLOCK_HOST);
603 
604     if ((now - pkt->creation_ms) > (*check_time)) {
605         trace_colo_old_packet_check_found(pkt->creation_ms);
606         return 0;
607     } else {
608         return 1;
609     }
610 }
611 
612 void colo_compare_register_notifier(Notifier *notify)
613 {
614     notifier_list_add(&colo_compare_notifiers, notify);
615 }
616 
617 void colo_compare_unregister_notifier(Notifier *notify)
618 {
619     notifier_remove(notify);
620 }
621 
622 static int colo_old_packet_check_one_conn(Connection *conn,
623                                           CompareState *s)
624 {
625     if (!g_queue_is_empty(&conn->primary_list)) {
626         if (g_queue_find_custom(&conn->primary_list,
627                                 &s->compare_timeout,
628                                 (GCompareFunc)colo_old_packet_check_one))
629             goto out;
630     }
631 
632     if (!g_queue_is_empty(&conn->secondary_list)) {
633         if (g_queue_find_custom(&conn->secondary_list,
634                                 &s->compare_timeout,
635                                 (GCompareFunc)colo_old_packet_check_one))
636             goto out;
637     }
638 
639     return 1;
640 
641 out:
642     /* Do checkpoint will flush old packet */
643     colo_compare_inconsistency_notify(s);
644     return 0;
645 }
646 
647 /*
648  * Look for old packets that the secondary hasn't matched,
649  * if we have some then we have to checkpoint to wake
650  * the secondary up.
651  */
652 static void colo_old_packet_check(void *opaque)
653 {
654     CompareState *s = opaque;
655 
656     /*
657      * If we find one old packet, stop finding job and notify
658      * COLO frame do checkpoint.
659      */
660     g_queue_find_custom(&s->conn_list, s,
661                         (GCompareFunc)colo_old_packet_check_one_conn);
662 }
663 
664 static void colo_compare_packet(CompareState *s, Connection *conn,
665                                 int (*HandlePacket)(Packet *spkt,
666                                 Packet *ppkt))
667 {
668     Packet *pkt = NULL;
669     GList *result = NULL;
670 
671     while (!g_queue_is_empty(&conn->primary_list) &&
672            !g_queue_is_empty(&conn->secondary_list)) {
673         pkt = g_queue_pop_tail(&conn->primary_list);
674         result = g_queue_find_custom(&conn->secondary_list,
675                  pkt, (GCompareFunc)HandlePacket);
676 
677         if (result) {
678             colo_release_primary_pkt(s, pkt);
679             packet_destroy(result->data, NULL);
680             g_queue_delete_link(&conn->secondary_list, result);
681         } else {
682             /*
683              * If one packet arrive late, the secondary_list or
684              * primary_list will be empty, so we can't compare it
685              * until next comparison. If the packets in the list are
686              * timeout, it will trigger a checkpoint request.
687              */
688             trace_colo_compare_main("packet different");
689             g_queue_push_tail(&conn->primary_list, pkt);
690 
691             colo_compare_inconsistency_notify(s);
692             break;
693         }
694     }
695 }
696 
697 /*
698  * Called from the compare thread on the primary
699  * for compare packet with secondary list of the
700  * specified connection when a new packet was
701  * queued to it.
702  */
703 static void colo_compare_connection(void *opaque, void *user_data)
704 {
705     CompareState *s = user_data;
706     Connection *conn = opaque;
707 
708     switch (conn->ip_proto) {
709     case IPPROTO_TCP:
710         colo_compare_tcp(s, conn);
711         break;
712     case IPPROTO_UDP:
713         colo_compare_packet(s, conn, colo_packet_compare_udp);
714         break;
715     case IPPROTO_ICMP:
716         colo_compare_packet(s, conn, colo_packet_compare_icmp);
717         break;
718     default:
719         colo_compare_packet(s, conn, colo_packet_compare_other);
720         break;
721     }
722 }
723 
724 static void coroutine_fn _compare_chr_send(void *opaque)
725 {
726     SendCo *sendco = opaque;
727     CompareState *s = sendco->s;
728     int ret = 0;
729 
730     while (!g_queue_is_empty(&sendco->send_list)) {
731         SendEntry *entry = g_queue_pop_tail(&sendco->send_list);
732         uint32_t len = htonl(entry->size);
733 
734         ret = qemu_chr_fe_write_all(sendco->chr, (uint8_t *)&len, sizeof(len));
735 
736         if (ret != sizeof(len)) {
737             g_free(entry->buf);
738             g_slice_free(SendEntry, entry);
739             goto err;
740         }
741 
742         if (!sendco->notify_remote_frame && s->vnet_hdr) {
743             /*
744              * We send vnet header len make other module(like filter-redirector)
745              * know how to parse net packet correctly.
746              */
747             len = htonl(entry->vnet_hdr_len);
748 
749             ret = qemu_chr_fe_write_all(sendco->chr,
750                                         (uint8_t *)&len,
751                                         sizeof(len));
752 
753             if (ret != sizeof(len)) {
754                 g_free(entry->buf);
755                 g_slice_free(SendEntry, entry);
756                 goto err;
757             }
758         }
759 
760         ret = qemu_chr_fe_write_all(sendco->chr,
761                                     (uint8_t *)entry->buf,
762                                     entry->size);
763 
764         if (ret != entry->size) {
765             g_free(entry->buf);
766             g_slice_free(SendEntry, entry);
767             goto err;
768         }
769 
770         g_free(entry->buf);
771         g_slice_free(SendEntry, entry);
772     }
773 
774     sendco->ret = 0;
775     goto out;
776 
777 err:
778     while (!g_queue_is_empty(&sendco->send_list)) {
779         SendEntry *entry = g_queue_pop_tail(&sendco->send_list);
780         g_free(entry->buf);
781         g_slice_free(SendEntry, entry);
782     }
783     sendco->ret = ret < 0 ? ret : -EIO;
784 out:
785     sendco->co = NULL;
786     sendco->done = true;
787     aio_wait_kick();
788 }
789 
790 static int compare_chr_send(CompareState *s,
791                             uint8_t *buf,
792                             uint32_t size,
793                             uint32_t vnet_hdr_len,
794                             bool notify_remote_frame,
795                             bool zero_copy)
796 {
797     SendCo *sendco;
798     SendEntry *entry;
799 
800     if (notify_remote_frame) {
801         sendco = &s->notify_sendco;
802     } else {
803         sendco = &s->out_sendco;
804     }
805 
806     if (!size) {
807         return -1;
808     }
809 
810     entry = g_slice_new(SendEntry);
811     entry->size = size;
812     entry->vnet_hdr_len = vnet_hdr_len;
813     if (zero_copy) {
814         entry->buf = buf;
815     } else {
816         entry->buf = g_malloc(size);
817         memcpy(entry->buf, buf, size);
818     }
819     g_queue_push_tail(&sendco->send_list, entry);
820 
821     if (sendco->done) {
822         sendco->co = qemu_coroutine_create(_compare_chr_send, sendco);
823         sendco->done = false;
824         qemu_coroutine_enter(sendco->co);
825         if (sendco->done) {
826             /* report early errors */
827             return sendco->ret;
828         }
829     }
830 
831     /* assume success */
832     return 0;
833 }
834 
835 static int compare_chr_can_read(void *opaque)
836 {
837     return COMPARE_READ_LEN_MAX;
838 }
839 
840 /*
841  * Called from the main thread on the primary for packets
842  * arriving over the socket from the primary.
843  */
844 static void compare_pri_chr_in(void *opaque, const uint8_t *buf, int size)
845 {
846     CompareState *s = COLO_COMPARE(opaque);
847     int ret;
848 
849     ret = net_fill_rstate(&s->pri_rs, buf, size);
850     if (ret == -1) {
851         qemu_chr_fe_set_handlers(&s->chr_pri_in, NULL, NULL, NULL, NULL,
852                                  NULL, NULL, true);
853         error_report("colo-compare primary_in error");
854     }
855 }
856 
857 /*
858  * Called from the main thread on the primary for packets
859  * arriving over the socket from the secondary.
860  */
861 static void compare_sec_chr_in(void *opaque, const uint8_t *buf, int size)
862 {
863     CompareState *s = COLO_COMPARE(opaque);
864     int ret;
865 
866     ret = net_fill_rstate(&s->sec_rs, buf, size);
867     if (ret == -1) {
868         qemu_chr_fe_set_handlers(&s->chr_sec_in, NULL, NULL, NULL, NULL,
869                                  NULL, NULL, true);
870         error_report("colo-compare secondary_in error");
871     }
872 }
873 
874 static void compare_notify_chr(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->notify_rs, buf, size);
880     if (ret == -1) {
881         qemu_chr_fe_set_handlers(&s->chr_notify_dev, NULL, NULL, NULL, NULL,
882                                  NULL, NULL, true);
883         error_report("colo-compare notify_dev error");
884     }
885 }
886 
887 /*
888  * Check old packet regularly so it can watch for any packets
889  * that the secondary hasn't produced equivalents of.
890  */
891 static void check_old_packet_regular(void *opaque)
892 {
893     CompareState *s = opaque;
894 
895     /* if have old packet we will notify checkpoint */
896     colo_old_packet_check(s);
897     timer_mod(s->packet_check_timer, qemu_clock_get_ms(QEMU_CLOCK_HOST) +
898               s->expired_scan_cycle);
899 }
900 
901 /* Public API, Used for COLO frame to notify compare event */
902 void colo_notify_compares_event(void *opaque, int event, Error **errp)
903 {
904     CompareState *s;
905     qemu_mutex_lock(&colo_compare_mutex);
906 
907     if (!colo_compare_active) {
908         qemu_mutex_unlock(&colo_compare_mutex);
909         return;
910     }
911 
912     qemu_mutex_lock(&event_mtx);
913     QTAILQ_FOREACH(s, &net_compares, next) {
914         s->event = event;
915         qemu_bh_schedule(s->event_bh);
916         event_unhandled_count++;
917     }
918     /* Wait all compare threads to finish handling this event */
919     while (event_unhandled_count > 0) {
920         qemu_cond_wait(&event_complete_cond, &event_mtx);
921     }
922 
923     qemu_mutex_unlock(&event_mtx);
924     qemu_mutex_unlock(&colo_compare_mutex);
925 }
926 
927 static void colo_compare_timer_init(CompareState *s)
928 {
929     AioContext *ctx = iothread_get_aio_context(s->iothread);
930 
931     s->packet_check_timer = aio_timer_new(ctx, QEMU_CLOCK_HOST,
932                                 SCALE_MS, check_old_packet_regular,
933                                 s);
934     timer_mod(s->packet_check_timer, qemu_clock_get_ms(QEMU_CLOCK_HOST) +
935               s->expired_scan_cycle);
936 }
937 
938 static void colo_compare_timer_del(CompareState *s)
939 {
940     if (s->packet_check_timer) {
941         timer_free(s->packet_check_timer);
942         s->packet_check_timer = NULL;
943     }
944  }
945 
946 static void colo_flush_packets(void *opaque, void *user_data);
947 
948 static void colo_compare_handle_event(void *opaque)
949 {
950     CompareState *s = opaque;
951 
952     switch (s->event) {
953     case COLO_EVENT_CHECKPOINT:
954         g_queue_foreach(&s->conn_list, colo_flush_packets, s);
955         break;
956     case COLO_EVENT_FAILOVER:
957         break;
958     default:
959         break;
960     }
961 
962     qemu_mutex_lock(&event_mtx);
963     assert(event_unhandled_count > 0);
964     event_unhandled_count--;
965     qemu_cond_broadcast(&event_complete_cond);
966     qemu_mutex_unlock(&event_mtx);
967 }
968 
969 static void colo_compare_iothread(CompareState *s)
970 {
971     AioContext *ctx = iothread_get_aio_context(s->iothread);
972     object_ref(OBJECT(s->iothread));
973     s->worker_context = iothread_get_g_main_context(s->iothread);
974 
975     qemu_chr_fe_set_handlers(&s->chr_pri_in, compare_chr_can_read,
976                              compare_pri_chr_in, NULL, NULL,
977                              s, s->worker_context, true);
978     qemu_chr_fe_set_handlers(&s->chr_sec_in, compare_chr_can_read,
979                              compare_sec_chr_in, NULL, NULL,
980                              s, s->worker_context, true);
981     if (s->notify_dev) {
982         qemu_chr_fe_set_handlers(&s->chr_notify_dev, compare_chr_can_read,
983                                  compare_notify_chr, NULL, NULL,
984                                  s, s->worker_context, true);
985     }
986 
987     colo_compare_timer_init(s);
988     s->event_bh = aio_bh_new(ctx, colo_compare_handle_event, s);
989 }
990 
991 static char *compare_get_pri_indev(Object *obj, Error **errp)
992 {
993     CompareState *s = COLO_COMPARE(obj);
994 
995     return g_strdup(s->pri_indev);
996 }
997 
998 static void compare_set_pri_indev(Object *obj, const char *value, Error **errp)
999 {
1000     CompareState *s = COLO_COMPARE(obj);
1001 
1002     g_free(s->pri_indev);
1003     s->pri_indev = g_strdup(value);
1004 }
1005 
1006 static char *compare_get_sec_indev(Object *obj, Error **errp)
1007 {
1008     CompareState *s = COLO_COMPARE(obj);
1009 
1010     return g_strdup(s->sec_indev);
1011 }
1012 
1013 static void compare_set_sec_indev(Object *obj, const char *value, Error **errp)
1014 {
1015     CompareState *s = COLO_COMPARE(obj);
1016 
1017     g_free(s->sec_indev);
1018     s->sec_indev = g_strdup(value);
1019 }
1020 
1021 static char *compare_get_outdev(Object *obj, Error **errp)
1022 {
1023     CompareState *s = COLO_COMPARE(obj);
1024 
1025     return g_strdup(s->outdev);
1026 }
1027 
1028 static void compare_set_outdev(Object *obj, const char *value, Error **errp)
1029 {
1030     CompareState *s = COLO_COMPARE(obj);
1031 
1032     g_free(s->outdev);
1033     s->outdev = g_strdup(value);
1034 }
1035 
1036 static bool compare_get_vnet_hdr(Object *obj, Error **errp)
1037 {
1038     CompareState *s = COLO_COMPARE(obj);
1039 
1040     return s->vnet_hdr;
1041 }
1042 
1043 static void compare_set_vnet_hdr(Object *obj,
1044                                  bool value,
1045                                  Error **errp)
1046 {
1047     CompareState *s = COLO_COMPARE(obj);
1048 
1049     s->vnet_hdr = value;
1050 }
1051 
1052 static char *compare_get_notify_dev(Object *obj, Error **errp)
1053 {
1054     CompareState *s = COLO_COMPARE(obj);
1055 
1056     return g_strdup(s->notify_dev);
1057 }
1058 
1059 static void compare_set_notify_dev(Object *obj, const char *value, Error **errp)
1060 {
1061     CompareState *s = COLO_COMPARE(obj);
1062 
1063     g_free(s->notify_dev);
1064     s->notify_dev = g_strdup(value);
1065 }
1066 
1067 static void compare_get_timeout(Object *obj, Visitor *v,
1068                                 const char *name, void *opaque,
1069                                 Error **errp)
1070 {
1071     CompareState *s = COLO_COMPARE(obj);
1072     uint64_t value = s->compare_timeout;
1073 
1074     visit_type_uint64(v, name, &value, errp);
1075 }
1076 
1077 static void compare_set_timeout(Object *obj, Visitor *v,
1078                                 const char *name, void *opaque,
1079                                 Error **errp)
1080 {
1081     CompareState *s = COLO_COMPARE(obj);
1082     uint32_t value;
1083 
1084     if (!visit_type_uint32(v, name, &value, errp)) {
1085         return;
1086     }
1087     if (!value) {
1088         error_setg(errp, "Property '%s.%s' requires a positive value",
1089                    object_get_typename(obj), name);
1090         return;
1091     }
1092     s->compare_timeout = value;
1093 }
1094 
1095 static void compare_get_expired_scan_cycle(Object *obj, Visitor *v,
1096                                            const char *name, void *opaque,
1097                                            Error **errp)
1098 {
1099     CompareState *s = COLO_COMPARE(obj);
1100     uint32_t value = s->expired_scan_cycle;
1101 
1102     visit_type_uint32(v, name, &value, errp);
1103 }
1104 
1105 static void compare_set_expired_scan_cycle(Object *obj, Visitor *v,
1106                                            const char *name, void *opaque,
1107                                            Error **errp)
1108 {
1109     CompareState *s = COLO_COMPARE(obj);
1110     uint32_t value;
1111 
1112     if (!visit_type_uint32(v, name, &value, errp)) {
1113         return;
1114     }
1115     if (!value) {
1116         error_setg(errp, "Property '%s.%s' requires a positive value",
1117                    object_get_typename(obj), name);
1118         return;
1119     }
1120     s->expired_scan_cycle = value;
1121 }
1122 
1123 static void get_max_queue_size(Object *obj, Visitor *v,
1124                                const char *name, void *opaque,
1125                                Error **errp)
1126 {
1127     uint32_t value = max_queue_size;
1128 
1129     visit_type_uint32(v, name, &value, errp);
1130 }
1131 
1132 static void set_max_queue_size(Object *obj, Visitor *v,
1133                                const char *name, void *opaque,
1134                                Error **errp)
1135 {
1136     uint64_t value;
1137 
1138     if (!visit_type_uint64(v, name, &value, errp)) {
1139         return;
1140     }
1141     if (!value) {
1142         error_setg(errp, "Property '%s.%s' requires a positive value",
1143                    object_get_typename(obj), name);
1144         return;
1145     }
1146     max_queue_size = value;
1147 }
1148 
1149 static void compare_pri_rs_finalize(SocketReadState *pri_rs)
1150 {
1151     CompareState *s = container_of(pri_rs, CompareState, pri_rs);
1152     Connection *conn = NULL;
1153 
1154     if (packet_enqueue(s, PRIMARY_IN, &conn)) {
1155         trace_colo_compare_main("primary: unsupported packet in");
1156         compare_chr_send(s,
1157                          pri_rs->buf,
1158                          pri_rs->packet_len,
1159                          pri_rs->vnet_hdr_len,
1160                          false,
1161                          false);
1162     } else {
1163         /* compare packet in the specified connection */
1164         colo_compare_connection(conn, s);
1165     }
1166 }
1167 
1168 static void compare_sec_rs_finalize(SocketReadState *sec_rs)
1169 {
1170     CompareState *s = container_of(sec_rs, CompareState, sec_rs);
1171     Connection *conn = NULL;
1172 
1173     if (packet_enqueue(s, SECONDARY_IN, &conn)) {
1174         trace_colo_compare_main("secondary: unsupported packet in");
1175     } else {
1176         /* compare packet in the specified connection */
1177         colo_compare_connection(conn, s);
1178     }
1179 }
1180 
1181 static void compare_notify_rs_finalize(SocketReadState *notify_rs)
1182 {
1183     CompareState *s = container_of(notify_rs, CompareState, notify_rs);
1184 
1185     const char msg[] = "COLO_COMPARE_GET_XEN_INIT";
1186     int ret;
1187 
1188     if (packet_matches_str("COLO_USERSPACE_PROXY_INIT",
1189                            notify_rs->buf,
1190                            notify_rs->packet_len)) {
1191         ret = compare_chr_send(s, (uint8_t *)msg, strlen(msg), 0, true, false);
1192         if (ret < 0) {
1193             error_report("Notify Xen COLO-frame INIT failed");
1194         }
1195     } else if (packet_matches_str("COLO_CHECKPOINT",
1196                                   notify_rs->buf,
1197                                   notify_rs->packet_len)) {
1198         /* colo-compare do checkpoint, flush pri packet and remove sec packet */
1199         g_queue_foreach(&s->conn_list, colo_flush_packets, s);
1200     } else {
1201         error_report("COLO compare got unsupported instruction");
1202     }
1203 }
1204 
1205 /*
1206  * Return 0 is success.
1207  * Return 1 is failed.
1208  */
1209 static int find_and_check_chardev(Chardev **chr,
1210                                   char *chr_name,
1211                                   Error **errp)
1212 {
1213     *chr = qemu_chr_find(chr_name);
1214     if (*chr == NULL) {
1215         error_setg(errp, "Device '%s' not found",
1216                    chr_name);
1217         return 1;
1218     }
1219 
1220     if (!qemu_chr_has_feature(*chr, QEMU_CHAR_FEATURE_RECONNECTABLE)) {
1221         error_setg(errp, "chardev \"%s\" is not reconnectable",
1222                    chr_name);
1223         return 1;
1224     }
1225 
1226     if (!qemu_chr_has_feature(*chr, QEMU_CHAR_FEATURE_GCONTEXT)) {
1227         error_setg(errp, "chardev \"%s\" cannot switch context",
1228                    chr_name);
1229         return 1;
1230     }
1231 
1232     return 0;
1233 }
1234 
1235 /*
1236  * Called from the main thread on the primary
1237  * to setup colo-compare.
1238  */
1239 static void colo_compare_complete(UserCreatable *uc, Error **errp)
1240 {
1241     CompareState *s = COLO_COMPARE(uc);
1242     Chardev *chr;
1243 
1244     if (!s->pri_indev || !s->sec_indev || !s->outdev || !s->iothread) {
1245         error_setg(errp, "colo compare needs 'primary_in' ,"
1246                    "'secondary_in','outdev','iothread' property set");
1247         return;
1248     } else if (!strcmp(s->pri_indev, s->outdev) ||
1249                !strcmp(s->sec_indev, s->outdev) ||
1250                !strcmp(s->pri_indev, s->sec_indev)) {
1251         error_setg(errp, "'indev' and 'outdev' could not be same "
1252                    "for compare module");
1253         return;
1254     }
1255 
1256     if (!s->compare_timeout) {
1257         /* Set default value to 3000 MS */
1258         s->compare_timeout = DEFAULT_TIME_OUT_MS;
1259     }
1260 
1261     if (!s->expired_scan_cycle) {
1262         /* Set default value to 1000 MS */
1263         s->expired_scan_cycle = REGULAR_PACKET_CHECK_MS;
1264     }
1265 
1266     if (!max_queue_size) {
1267         /* Set default queue size to 1024 */
1268         max_queue_size = MAX_QUEUE_SIZE;
1269     }
1270 
1271     if (find_and_check_chardev(&chr, s->pri_indev, errp) ||
1272         !qemu_chr_fe_init(&s->chr_pri_in, chr, errp)) {
1273         return;
1274     }
1275 
1276     if (find_and_check_chardev(&chr, s->sec_indev, errp) ||
1277         !qemu_chr_fe_init(&s->chr_sec_in, chr, errp)) {
1278         return;
1279     }
1280 
1281     if (find_and_check_chardev(&chr, s->outdev, errp) ||
1282         !qemu_chr_fe_init(&s->chr_out, chr, errp)) {
1283         return;
1284     }
1285 
1286     net_socket_rs_init(&s->pri_rs, compare_pri_rs_finalize, s->vnet_hdr);
1287     net_socket_rs_init(&s->sec_rs, compare_sec_rs_finalize, s->vnet_hdr);
1288 
1289     /* Try to enable remote notify chardev, currently just for Xen COLO */
1290     if (s->notify_dev) {
1291         if (find_and_check_chardev(&chr, s->notify_dev, errp) ||
1292             !qemu_chr_fe_init(&s->chr_notify_dev, chr, errp)) {
1293             return;
1294         }
1295 
1296         net_socket_rs_init(&s->notify_rs, compare_notify_rs_finalize,
1297                            s->vnet_hdr);
1298     }
1299 
1300     s->out_sendco.s = s;
1301     s->out_sendco.chr = &s->chr_out;
1302     s->out_sendco.notify_remote_frame = false;
1303     s->out_sendco.done = true;
1304     g_queue_init(&s->out_sendco.send_list);
1305 
1306     if (s->notify_dev) {
1307         s->notify_sendco.s = s;
1308         s->notify_sendco.chr = &s->chr_notify_dev;
1309         s->notify_sendco.notify_remote_frame = true;
1310         s->notify_sendco.done = true;
1311         g_queue_init(&s->notify_sendco.send_list);
1312     }
1313 
1314     g_queue_init(&s->conn_list);
1315 
1316     s->connection_track_table = g_hash_table_new_full(connection_key_hash,
1317                                                       connection_key_equal,
1318                                                       g_free,
1319                                                       NULL);
1320 
1321     colo_compare_iothread(s);
1322 
1323     qemu_mutex_lock(&colo_compare_mutex);
1324     if (!colo_compare_active) {
1325         qemu_mutex_init(&event_mtx);
1326         qemu_cond_init(&event_complete_cond);
1327         colo_compare_active = true;
1328     }
1329     QTAILQ_INSERT_TAIL(&net_compares, s, next);
1330     qemu_mutex_unlock(&colo_compare_mutex);
1331 
1332     return;
1333 }
1334 
1335 static void colo_flush_packets(void *opaque, void *user_data)
1336 {
1337     CompareState *s = user_data;
1338     Connection *conn = opaque;
1339     Packet *pkt = NULL;
1340 
1341     while (!g_queue_is_empty(&conn->primary_list)) {
1342         pkt = g_queue_pop_tail(&conn->primary_list);
1343         compare_chr_send(s,
1344                          pkt->data,
1345                          pkt->size,
1346                          pkt->vnet_hdr_len,
1347                          false,
1348                          true);
1349         packet_destroy_partial(pkt, NULL);
1350     }
1351     while (!g_queue_is_empty(&conn->secondary_list)) {
1352         pkt = g_queue_pop_tail(&conn->secondary_list);
1353         packet_destroy(pkt, NULL);
1354     }
1355 }
1356 
1357 static void colo_compare_class_init(ObjectClass *oc, void *data)
1358 {
1359     UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);
1360 
1361     ucc->complete = colo_compare_complete;
1362 }
1363 
1364 static void colo_compare_init(Object *obj)
1365 {
1366     CompareState *s = COLO_COMPARE(obj);
1367 
1368     object_property_add_str(obj, "primary_in",
1369                             compare_get_pri_indev, compare_set_pri_indev);
1370     object_property_add_str(obj, "secondary_in",
1371                             compare_get_sec_indev, compare_set_sec_indev);
1372     object_property_add_str(obj, "outdev",
1373                             compare_get_outdev, compare_set_outdev);
1374     object_property_add_link(obj, "iothread", TYPE_IOTHREAD,
1375                             (Object **)&s->iothread,
1376                             object_property_allow_set_link,
1377                             OBJ_PROP_LINK_STRONG);
1378     /* This parameter just for Xen COLO */
1379     object_property_add_str(obj, "notify_dev",
1380                             compare_get_notify_dev, compare_set_notify_dev);
1381 
1382     object_property_add(obj, "compare_timeout", "uint64",
1383                         compare_get_timeout,
1384                         compare_set_timeout, NULL, NULL);
1385 
1386     object_property_add(obj, "expired_scan_cycle", "uint32",
1387                         compare_get_expired_scan_cycle,
1388                         compare_set_expired_scan_cycle, NULL, NULL);
1389 
1390     object_property_add(obj, "max_queue_size", "uint32",
1391                         get_max_queue_size,
1392                         set_max_queue_size, NULL, NULL);
1393 
1394     s->vnet_hdr = false;
1395     object_property_add_bool(obj, "vnet_hdr_support", compare_get_vnet_hdr,
1396                              compare_set_vnet_hdr);
1397 }
1398 
1399 void colo_compare_cleanup(void)
1400 {
1401     CompareState *tmp = NULL;
1402     CompareState *n = NULL;
1403 
1404     QTAILQ_FOREACH_SAFE(tmp, &net_compares, next, n) {
1405         object_unparent(OBJECT(tmp));
1406     }
1407 }
1408 
1409 static void colo_compare_finalize(Object *obj)
1410 {
1411     CompareState *s = COLO_COMPARE(obj);
1412     CompareState *tmp = NULL;
1413 
1414     qemu_mutex_lock(&colo_compare_mutex);
1415     QTAILQ_FOREACH(tmp, &net_compares, next) {
1416         if (tmp == s) {
1417             QTAILQ_REMOVE(&net_compares, s, next);
1418             break;
1419         }
1420     }
1421     if (QTAILQ_EMPTY(&net_compares)) {
1422         colo_compare_active = false;
1423         qemu_mutex_destroy(&event_mtx);
1424         qemu_cond_destroy(&event_complete_cond);
1425     }
1426     qemu_mutex_unlock(&colo_compare_mutex);
1427 
1428     qemu_chr_fe_deinit(&s->chr_pri_in, false);
1429     qemu_chr_fe_deinit(&s->chr_sec_in, false);
1430     qemu_chr_fe_deinit(&s->chr_out, false);
1431     if (s->notify_dev) {
1432         qemu_chr_fe_deinit(&s->chr_notify_dev, false);
1433     }
1434 
1435     colo_compare_timer_del(s);
1436 
1437     qemu_bh_delete(s->event_bh);
1438 
1439     AioContext *ctx = iothread_get_aio_context(s->iothread);
1440     AIO_WAIT_WHILE(ctx, !s->out_sendco.done);
1441     if (s->notify_dev) {
1442         AIO_WAIT_WHILE(ctx, !s->notify_sendco.done);
1443     }
1444 
1445     /* Release all unhandled packets after compare thead exited */
1446     g_queue_foreach(&s->conn_list, colo_flush_packets, s);
1447     AIO_WAIT_WHILE(NULL, !s->out_sendco.done);
1448 
1449     g_queue_clear(&s->conn_list);
1450     g_queue_clear(&s->out_sendco.send_list);
1451     if (s->notify_dev) {
1452         g_queue_clear(&s->notify_sendco.send_list);
1453     }
1454 
1455     if (s->connection_track_table) {
1456         g_hash_table_destroy(s->connection_track_table);
1457     }
1458 
1459     object_unref(OBJECT(s->iothread));
1460 
1461     g_free(s->pri_indev);
1462     g_free(s->sec_indev);
1463     g_free(s->outdev);
1464     g_free(s->notify_dev);
1465 }
1466 
1467 static void __attribute__((__constructor__)) colo_compare_init_globals(void)
1468 {
1469     colo_compare_active = false;
1470     qemu_mutex_init(&colo_compare_mutex);
1471 }
1472 
1473 static const TypeInfo colo_compare_info = {
1474     .name = TYPE_COLO_COMPARE,
1475     .parent = TYPE_OBJECT,
1476     .instance_size = sizeof(CompareState),
1477     .instance_init = colo_compare_init,
1478     .instance_finalize = colo_compare_finalize,
1479     .class_size = sizeof(CompareClass),
1480     .class_init = colo_compare_class_init,
1481     .interfaces = (InterfaceInfo[]) {
1482         { TYPE_USER_CREATABLE },
1483         { }
1484     }
1485 };
1486 
1487 static void register_types(void)
1488 {
1489     type_register_static(&colo_compare_info);
1490 }
1491 
1492 type_init(register_types);
1493