xref: /openbmc/qemu/net/colo-compare.c (revision 33609e95)
1 /*
2  * COarse-grain LOck-stepping Virtual Machines for Non-stop Service (COLO)
3  * (a.k.a. Fault Tolerance or Continuous Replication)
4  *
5  * Copyright (c) 2016 HUAWEI TECHNOLOGIES CO., LTD.
6  * Copyright (c) 2016 FUJITSU LIMITED
7  * Copyright (c) 2016 Intel Corporation
8  *
9  * Author: Zhang Chen <zhangchen.fnst@cn.fujitsu.com>
10  *
11  * This work is licensed under the terms of the GNU GPL, version 2 or
12  * later.  See the COPYING file in the top-level directory.
13  */
14 
15 #include "qemu/osdep.h"
16 #include "qemu-common.h"
17 #include "qemu/error-report.h"
18 #include "trace.h"
19 #include "qapi/error.h"
20 #include "net/net.h"
21 #include "net/eth.h"
22 #include "qom/object_interfaces.h"
23 #include "qemu/iov.h"
24 #include "qom/object.h"
25 #include "net/queue.h"
26 #include "chardev/char-fe.h"
27 #include "qemu/sockets.h"
28 #include "colo.h"
29 #include "sysemu/iothread.h"
30 #include "net/colo-compare.h"
31 #include "migration/colo.h"
32 #include "migration/migration.h"
33 #include "util.h"
34 
35 #include "block/aio-wait.h"
36 #include "qemu/coroutine.h"
37 
38 #define TYPE_COLO_COMPARE "colo-compare"
39 typedef struct CompareState CompareState;
40 DECLARE_INSTANCE_CHECKER(CompareState, COLO_COMPARE,
41                          TYPE_COLO_COMPARE)
42 
43 static QTAILQ_HEAD(, CompareState) net_compares =
44        QTAILQ_HEAD_INITIALIZER(net_compares);
45 
46 static NotifierList colo_compare_notifiers =
47     NOTIFIER_LIST_INITIALIZER(colo_compare_notifiers);
48 
49 #define COMPARE_READ_LEN_MAX NET_BUFSIZE
50 #define MAX_QUEUE_SIZE 1024
51 
52 #define COLO_COMPARE_FREE_PRIMARY     0x01
53 #define COLO_COMPARE_FREE_SECONDARY   0x02
54 
55 #define REGULAR_PACKET_CHECK_MS 3000
56 #define DEFAULT_TIME_OUT_MS 3000
57 
58 /* #define DEBUG_COLO_PACKETS */
59 
60 static QemuMutex colo_compare_mutex;
61 static bool colo_compare_active;
62 static QemuMutex event_mtx;
63 static QemuCond event_complete_cond;
64 static int event_unhandled_count;
65 static uint32_t max_queue_size;
66 
67 /*
68  *  + CompareState ++
69  *  |               |
70  *  +---------------+   +---------------+         +---------------+
71  *  |   conn list   + - >      conn     + ------- >      conn     + -- > ......
72  *  +---------------+   +---------------+         +---------------+
73  *  |               |     |           |             |          |
74  *  +---------------+ +---v----+  +---v----+    +---v----+ +---v----+
75  *                    |primary |  |secondary    |primary | |secondary
76  *                    |packet  |  |packet  +    |packet  | |packet  +
77  *                    +--------+  +--------+    +--------+ +--------+
78  *                        |           |             |          |
79  *                    +---v----+  +---v----+    +---v----+ +---v----+
80  *                    |primary |  |secondary    |primary | |secondary
81  *                    |packet  |  |packet  +    |packet  | |packet  +
82  *                    +--------+  +--------+    +--------+ +--------+
83  *                        |           |             |          |
84  *                    +---v----+  +---v----+    +---v----+ +---v----+
85  *                    |primary |  |secondary    |primary | |secondary
86  *                    |packet  |  |packet  +    |packet  | |packet  +
87  *                    +--------+  +--------+    +--------+ +--------+
88  */
89 
90 typedef struct SendCo {
91     Coroutine *co;
92     struct CompareState *s;
93     CharBackend *chr;
94     GQueue send_list;
95     bool notify_remote_frame;
96     bool done;
97     int ret;
98 } SendCo;
99 
100 typedef struct SendEntry {
101     uint32_t size;
102     uint32_t vnet_hdr_len;
103     uint8_t *buf;
104 } SendEntry;
105 
106 struct CompareState {
107     Object parent;
108 
109     char *pri_indev;
110     char *sec_indev;
111     char *outdev;
112     char *notify_dev;
113     CharBackend chr_pri_in;
114     CharBackend chr_sec_in;
115     CharBackend chr_out;
116     CharBackend chr_notify_dev;
117     SocketReadState pri_rs;
118     SocketReadState sec_rs;
119     SocketReadState notify_rs;
120     SendCo out_sendco;
121     SendCo notify_sendco;
122     bool vnet_hdr;
123     uint32_t compare_timeout;
124     uint32_t expired_scan_cycle;
125 
126     /*
127      * Record the connection that through the NIC
128      * Element type: Connection
129      */
130     GQueue conn_list;
131     /* Record the connection without repetition */
132     GHashTable *connection_track_table;
133 
134     IOThread *iothread;
135     GMainContext *worker_context;
136     QEMUTimer *packet_check_timer;
137 
138     QEMUBH *event_bh;
139     enum colo_event event;
140 
141     QTAILQ_ENTRY(CompareState) next;
142 };
143 
144 typedef struct CompareClass {
145     ObjectClass parent_class;
146 } CompareClass;
147 
148 enum {
149     PRIMARY_IN = 0,
150     SECONDARY_IN,
151 };
152 
153 static const char *colo_mode[] = {
154     [PRIMARY_IN] = "primary",
155     [SECONDARY_IN] = "secondary",
156 };
157 
158 static int compare_chr_send(CompareState *s,
159                             uint8_t *buf,
160                             uint32_t size,
161                             uint32_t vnet_hdr_len,
162                             bool notify_remote_frame,
163                             bool zero_copy);
164 
165 static bool packet_matches_str(const char *str,
166                                const uint8_t *buf,
167                                uint32_t packet_len)
168 {
169     if (packet_len != strlen(str)) {
170         return false;
171     }
172 
173     return !memcmp(str, buf, strlen(str));
174 }
175 
176 static void notify_remote_frame(CompareState *s)
177 {
178     char msg[] = "DO_CHECKPOINT";
179     int ret = 0;
180 
181     ret = compare_chr_send(s, (uint8_t *)msg, strlen(msg), 0, true, false);
182     if (ret < 0) {
183         error_report("Notify Xen COLO-frame failed");
184     }
185 }
186 
187 static void colo_compare_inconsistency_notify(CompareState *s)
188 {
189     if (s->notify_dev) {
190         notify_remote_frame(s);
191     } else {
192         notifier_list_notify(&colo_compare_notifiers,
193                              migrate_get_current());
194     }
195 }
196 
197 /* Use restricted to colo_insert_packet() */
198 static gint seq_sorter(Packet *a, Packet *b, gpointer data)
199 {
200     return a->tcp_seq - b->tcp_seq;
201 }
202 
203 static void fill_pkt_tcp_info(void *data, uint32_t *max_ack)
204 {
205     Packet *pkt = data;
206     struct tcp_hdr *tcphd;
207 
208     tcphd = (struct tcp_hdr *)pkt->transport_header;
209 
210     pkt->tcp_seq = ntohl(tcphd->th_seq);
211     pkt->tcp_ack = ntohl(tcphd->th_ack);
212     *max_ack = *max_ack > pkt->tcp_ack ? *max_ack : pkt->tcp_ack;
213     pkt->header_size = pkt->transport_header - (uint8_t *)pkt->data
214                        + (tcphd->th_off << 2) - pkt->vnet_hdr_len;
215     pkt->payload_size = pkt->size - pkt->header_size;
216     pkt->seq_end = pkt->tcp_seq + pkt->payload_size;
217     pkt->flags = tcphd->th_flags;
218 }
219 
220 /*
221  * Return 1 on success, if return 0 means the
222  * packet will be dropped
223  */
224 static int colo_insert_packet(GQueue *queue, Packet *pkt, uint32_t *max_ack)
225 {
226     if (g_queue_get_length(queue) <= max_queue_size) {
227         if (pkt->ip->ip_p == IPPROTO_TCP) {
228             fill_pkt_tcp_info(pkt, max_ack);
229             g_queue_insert_sorted(queue,
230                                   pkt,
231                                   (GCompareDataFunc)seq_sorter,
232                                   NULL);
233         } else {
234             g_queue_push_tail(queue, pkt);
235         }
236         return 1;
237     }
238     return 0;
239 }
240 
241 /*
242  * Return 0 on success, if return -1 means the pkt
243  * is unsupported(arp and ipv6) and will be sent later
244  */
245 static int packet_enqueue(CompareState *s, int mode, Connection **con)
246 {
247     ConnectionKey key;
248     Packet *pkt = NULL;
249     Connection *conn;
250     int ret;
251 
252     if (mode == PRIMARY_IN) {
253         pkt = packet_new(s->pri_rs.buf,
254                          s->pri_rs.packet_len,
255                          s->pri_rs.vnet_hdr_len);
256     } else {
257         pkt = packet_new(s->sec_rs.buf,
258                          s->sec_rs.packet_len,
259                          s->sec_rs.vnet_hdr_len);
260     }
261 
262     if (parse_packet_early(pkt)) {
263         packet_destroy(pkt, NULL);
264         pkt = NULL;
265         return -1;
266     }
267     fill_connection_key(pkt, &key);
268 
269     conn = connection_get(s->connection_track_table,
270                           &key,
271                           &s->conn_list);
272 
273     if (!conn->processing) {
274         g_queue_push_tail(&s->conn_list, conn);
275         conn->processing = true;
276     }
277 
278     if (mode == PRIMARY_IN) {
279         ret = colo_insert_packet(&conn->primary_list, pkt, &conn->pack);
280     } else {
281         ret = colo_insert_packet(&conn->secondary_list, pkt, &conn->sack);
282     }
283 
284     if (!ret) {
285         trace_colo_compare_drop_packet(colo_mode[mode],
286             "queue size too big, drop packet");
287         packet_destroy(pkt, NULL);
288         pkt = NULL;
289     }
290 
291     *con = conn;
292 
293     return 0;
294 }
295 
296 static inline bool after(uint32_t seq1, uint32_t seq2)
297 {
298         return (int32_t)(seq1 - seq2) > 0;
299 }
300 
301 static void colo_release_primary_pkt(CompareState *s, Packet *pkt)
302 {
303     int ret;
304     ret = compare_chr_send(s,
305                            pkt->data,
306                            pkt->size,
307                            pkt->vnet_hdr_len,
308                            false,
309                            true);
310     if (ret < 0) {
311         error_report("colo send primary packet failed");
312     }
313     trace_colo_compare_main("packet same and release packet");
314     packet_destroy_partial(pkt, NULL);
315 }
316 
317 /*
318  * The IP packets sent by primary and secondary
319  * will be compared in here
320  * TODO support ip fragment, Out-Of-Order
321  * return:    0  means packet same
322  *            > 0 || < 0 means packet different
323  */
324 static int colo_compare_packet_payload(Packet *ppkt,
325                                        Packet *spkt,
326                                        uint16_t poffset,
327                                        uint16_t soffset,
328                                        uint16_t len)
329 
330 {
331     if (trace_event_get_state_backends(TRACE_COLO_COMPARE_IP_INFO)) {
332         char pri_ip_src[20], pri_ip_dst[20], sec_ip_src[20], sec_ip_dst[20];
333 
334         strcpy(pri_ip_src, inet_ntoa(ppkt->ip->ip_src));
335         strcpy(pri_ip_dst, inet_ntoa(ppkt->ip->ip_dst));
336         strcpy(sec_ip_src, inet_ntoa(spkt->ip->ip_src));
337         strcpy(sec_ip_dst, inet_ntoa(spkt->ip->ip_dst));
338 
339         trace_colo_compare_ip_info(ppkt->size, pri_ip_src,
340                                    pri_ip_dst, spkt->size,
341                                    sec_ip_src, sec_ip_dst);
342     }
343 
344     return memcmp(ppkt->data + poffset, spkt->data + soffset, len);
345 }
346 
347 /*
348  * return true means that the payload is consist and
349  * need to make the next comparison, false means do
350  * the checkpoint
351 */
352 static bool colo_mark_tcp_pkt(Packet *ppkt, Packet *spkt,
353                               int8_t *mark, uint32_t max_ack)
354 {
355     *mark = 0;
356 
357     if (ppkt->tcp_seq == spkt->tcp_seq && ppkt->seq_end == spkt->seq_end) {
358         if (!colo_compare_packet_payload(ppkt, spkt,
359                                         ppkt->header_size, spkt->header_size,
360                                         ppkt->payload_size)) {
361             *mark = COLO_COMPARE_FREE_SECONDARY | COLO_COMPARE_FREE_PRIMARY;
362             return true;
363         }
364     }
365 
366     /* one part of secondary packet payload still need to be compared */
367     if (!after(ppkt->seq_end, spkt->seq_end)) {
368         if (!colo_compare_packet_payload(ppkt, spkt,
369                                         ppkt->header_size + ppkt->offset,
370                                         spkt->header_size + spkt->offset,
371                                         ppkt->payload_size - ppkt->offset)) {
372             if (!after(ppkt->tcp_ack, max_ack)) {
373                 *mark = COLO_COMPARE_FREE_PRIMARY;
374                 spkt->offset += ppkt->payload_size - ppkt->offset;
375                 return true;
376             } else {
377                 /* secondary guest hasn't ack the data, don't send
378                  * out this packet
379                  */
380                 return false;
381             }
382         }
383     } else {
384         /* primary packet is longer than secondary packet, compare
385          * the same part and mark the primary packet offset
386          */
387         if (!colo_compare_packet_payload(ppkt, spkt,
388                                         ppkt->header_size + ppkt->offset,
389                                         spkt->header_size + spkt->offset,
390                                         spkt->payload_size - spkt->offset)) {
391             *mark = COLO_COMPARE_FREE_SECONDARY;
392             ppkt->offset += spkt->payload_size - spkt->offset;
393             return true;
394         }
395     }
396 
397     return false;
398 }
399 
400 static void colo_compare_tcp(CompareState *s, Connection *conn)
401 {
402     Packet *ppkt = NULL, *spkt = NULL;
403     int8_t mark;
404 
405     /*
406      * If ppkt and spkt have the same payload, but ppkt's ACK
407      * is greater than spkt's ACK, in this case we can not
408      * send the ppkt because it will cause the secondary guest
409      * to miss sending some data in the next. Therefore, we
410      * record the maximum ACK in the current queue at both
411      * primary side and secondary side. Only when the ack is
412      * less than the smaller of the two maximum ack, then we
413      * can ensure that the packet's payload is acknowledged by
414      * primary and secondary.
415     */
416     uint32_t min_ack = conn->pack > conn->sack ? conn->sack : conn->pack;
417 
418 pri:
419     if (g_queue_is_empty(&conn->primary_list)) {
420         return;
421     }
422     ppkt = g_queue_pop_head(&conn->primary_list);
423 sec:
424     if (g_queue_is_empty(&conn->secondary_list)) {
425         g_queue_push_head(&conn->primary_list, ppkt);
426         return;
427     }
428     spkt = g_queue_pop_head(&conn->secondary_list);
429 
430     if (ppkt->tcp_seq == ppkt->seq_end) {
431         colo_release_primary_pkt(s, ppkt);
432         ppkt = NULL;
433     }
434 
435     if (ppkt && conn->compare_seq && !after(ppkt->seq_end, conn->compare_seq)) {
436         trace_colo_compare_main("pri: this packet has compared");
437         colo_release_primary_pkt(s, ppkt);
438         ppkt = NULL;
439     }
440 
441     if (spkt->tcp_seq == spkt->seq_end) {
442         packet_destroy(spkt, NULL);
443         if (!ppkt) {
444             goto pri;
445         } else {
446             goto sec;
447         }
448     } else {
449         if (conn->compare_seq && !after(spkt->seq_end, conn->compare_seq)) {
450             trace_colo_compare_main("sec: this packet has compared");
451             packet_destroy(spkt, NULL);
452             if (!ppkt) {
453                 goto pri;
454             } else {
455                 goto sec;
456             }
457         }
458         if (!ppkt) {
459             g_queue_push_head(&conn->secondary_list, spkt);
460             goto pri;
461         }
462     }
463 
464     if (colo_mark_tcp_pkt(ppkt, spkt, &mark, min_ack)) {
465         trace_colo_compare_tcp_info("pri",
466                                     ppkt->tcp_seq, ppkt->tcp_ack,
467                                     ppkt->header_size, ppkt->payload_size,
468                                     ppkt->offset, ppkt->flags);
469 
470         trace_colo_compare_tcp_info("sec",
471                                     spkt->tcp_seq, spkt->tcp_ack,
472                                     spkt->header_size, spkt->payload_size,
473                                     spkt->offset, spkt->flags);
474 
475         if (mark == COLO_COMPARE_FREE_PRIMARY) {
476             conn->compare_seq = ppkt->seq_end;
477             colo_release_primary_pkt(s, ppkt);
478             g_queue_push_head(&conn->secondary_list, spkt);
479             goto pri;
480         }
481         if (mark == COLO_COMPARE_FREE_SECONDARY) {
482             conn->compare_seq = spkt->seq_end;
483             packet_destroy(spkt, NULL);
484             goto sec;
485         }
486         if (mark == (COLO_COMPARE_FREE_PRIMARY | COLO_COMPARE_FREE_SECONDARY)) {
487             conn->compare_seq = ppkt->seq_end;
488             colo_release_primary_pkt(s, ppkt);
489             packet_destroy(spkt, NULL);
490             goto pri;
491         }
492     } else {
493         g_queue_push_head(&conn->primary_list, ppkt);
494         g_queue_push_head(&conn->secondary_list, spkt);
495 
496 #ifdef DEBUG_COLO_PACKETS
497         qemu_hexdump(stderr, "colo-compare ppkt", ppkt->data, ppkt->size);
498         qemu_hexdump(stderr, "colo-compare spkt", spkt->data, spkt->size);
499 #endif
500 
501         colo_compare_inconsistency_notify(s);
502     }
503 }
504 
505 
506 /*
507  * Called from the compare thread on the primary
508  * for compare udp packet
509  */
510 static int colo_packet_compare_udp(Packet *spkt, Packet *ppkt)
511 {
512     uint16_t network_header_length = ppkt->ip->ip_hl << 2;
513     uint16_t offset = network_header_length + ETH_HLEN + ppkt->vnet_hdr_len;
514 
515     trace_colo_compare_main("compare udp");
516 
517     /*
518      * Because of ppkt and spkt are both in the same connection,
519      * The ppkt's src ip, dst ip, src port, dst port, ip_proto all are
520      * same with spkt. In addition, IP header's Identification is a random
521      * field, we can handle it in IP fragmentation function later.
522      * COLO just concern the response net packet payload from primary guest
523      * and secondary guest are same or not, So we ignored all IP header include
524      * other field like TOS,TTL,IP Checksum. we only need to compare
525      * the ip payload here.
526      */
527     if (ppkt->size != spkt->size) {
528         trace_colo_compare_main("UDP: payload size of packets are different");
529         return -1;
530     }
531     if (colo_compare_packet_payload(ppkt, spkt, offset, offset,
532                                     ppkt->size - offset)) {
533         trace_colo_compare_udp_miscompare("primary pkt size", ppkt->size);
534         trace_colo_compare_udp_miscompare("Secondary pkt size", spkt->size);
535 #ifdef DEBUG_COLO_PACKETS
536         qemu_hexdump(stderr, "colo-compare pri pkt", ppkt->data, ppkt->size);
537         qemu_hexdump(stderr, "colo-compare sec pkt", spkt->data, spkt->size);
538 #endif
539         return -1;
540     } else {
541         return 0;
542     }
543 }
544 
545 /*
546  * Called from the compare thread on the primary
547  * for compare icmp packet
548  */
549 static int colo_packet_compare_icmp(Packet *spkt, Packet *ppkt)
550 {
551     uint16_t network_header_length = ppkt->ip->ip_hl << 2;
552     uint16_t offset = network_header_length + ETH_HLEN + ppkt->vnet_hdr_len;
553 
554     trace_colo_compare_main("compare icmp");
555 
556     /*
557      * Because of ppkt and spkt are both in the same connection,
558      * The ppkt's src ip, dst ip, src port, dst port, ip_proto all are
559      * same with spkt. In addition, IP header's Identification is a random
560      * field, we can handle it in IP fragmentation function later.
561      * COLO just concern the response net packet payload from primary guest
562      * and secondary guest are same or not, So we ignored all IP header include
563      * other field like TOS,TTL,IP Checksum. we only need to compare
564      * the ip payload here.
565      */
566     if (ppkt->size != spkt->size) {
567         trace_colo_compare_main("ICMP: payload size of packets are different");
568         return -1;
569     }
570     if (colo_compare_packet_payload(ppkt, spkt, offset, offset,
571                                     ppkt->size - offset)) {
572         trace_colo_compare_icmp_miscompare("primary pkt size",
573                                            ppkt->size);
574         trace_colo_compare_icmp_miscompare("Secondary pkt size",
575                                            spkt->size);
576 #ifdef DEBUG_COLO_PACKETS
577         qemu_hexdump(stderr, "colo-compare pri pkt", ppkt->data, ppkt->size);
578         qemu_hexdump(stderr, "colo-compare sec pkt", spkt->data, spkt->size);
579 #endif
580         return -1;
581     } else {
582         return 0;
583     }
584 }
585 
586 /*
587  * Called from the compare thread on the primary
588  * for compare other packet
589  */
590 static int colo_packet_compare_other(Packet *spkt, Packet *ppkt)
591 {
592     uint16_t offset = ppkt->vnet_hdr_len;
593 
594     trace_colo_compare_main("compare other");
595     if (trace_event_get_state_backends(TRACE_COLO_COMPARE_IP_INFO)) {
596         char pri_ip_src[20], pri_ip_dst[20], sec_ip_src[20], sec_ip_dst[20];
597 
598         strcpy(pri_ip_src, inet_ntoa(ppkt->ip->ip_src));
599         strcpy(pri_ip_dst, inet_ntoa(ppkt->ip->ip_dst));
600         strcpy(sec_ip_src, inet_ntoa(spkt->ip->ip_src));
601         strcpy(sec_ip_dst, inet_ntoa(spkt->ip->ip_dst));
602 
603         trace_colo_compare_ip_info(ppkt->size, pri_ip_src,
604                                    pri_ip_dst, spkt->size,
605                                    sec_ip_src, sec_ip_dst);
606     }
607 
608     if (ppkt->size != spkt->size) {
609         trace_colo_compare_main("Other: payload size of packets are different");
610         return -1;
611     }
612     return colo_compare_packet_payload(ppkt, spkt, offset, offset,
613                                        ppkt->size - offset);
614 }
615 
616 static int colo_old_packet_check_one(Packet *pkt, int64_t *check_time)
617 {
618     int64_t now = qemu_clock_get_ms(QEMU_CLOCK_HOST);
619 
620     if ((now - pkt->creation_ms) > (*check_time)) {
621         trace_colo_old_packet_check_found(pkt->creation_ms);
622         return 0;
623     } else {
624         return 1;
625     }
626 }
627 
628 void colo_compare_register_notifier(Notifier *notify)
629 {
630     notifier_list_add(&colo_compare_notifiers, notify);
631 }
632 
633 void colo_compare_unregister_notifier(Notifier *notify)
634 {
635     notifier_remove(notify);
636 }
637 
638 static int colo_old_packet_check_one_conn(Connection *conn,
639                                           CompareState *s)
640 {
641     GList *result = NULL;
642 
643     result = g_queue_find_custom(&conn->primary_list,
644                                  &s->compare_timeout,
645                                  (GCompareFunc)colo_old_packet_check_one);
646 
647     if (result) {
648         /* Do checkpoint will flush old packet */
649         colo_compare_inconsistency_notify(s);
650         return 0;
651     }
652 
653     return 1;
654 }
655 
656 /*
657  * Look for old packets that the secondary hasn't matched,
658  * if we have some then we have to checkpoint to wake
659  * the secondary up.
660  */
661 static void colo_old_packet_check(void *opaque)
662 {
663     CompareState *s = opaque;
664 
665     /*
666      * If we find one old packet, stop finding job and notify
667      * COLO frame do checkpoint.
668      */
669     g_queue_find_custom(&s->conn_list, s,
670                         (GCompareFunc)colo_old_packet_check_one_conn);
671 }
672 
673 static void colo_compare_packet(CompareState *s, Connection *conn,
674                                 int (*HandlePacket)(Packet *spkt,
675                                 Packet *ppkt))
676 {
677     Packet *pkt = NULL;
678     GList *result = NULL;
679 
680     while (!g_queue_is_empty(&conn->primary_list) &&
681            !g_queue_is_empty(&conn->secondary_list)) {
682         pkt = g_queue_pop_head(&conn->primary_list);
683         result = g_queue_find_custom(&conn->secondary_list,
684                  pkt, (GCompareFunc)HandlePacket);
685 
686         if (result) {
687             colo_release_primary_pkt(s, pkt);
688             g_queue_remove(&conn->secondary_list, result->data);
689         } else {
690             /*
691              * If one packet arrive late, the secondary_list or
692              * primary_list will be empty, so we can't compare it
693              * until next comparison. If the packets in the list are
694              * timeout, it will trigger a checkpoint request.
695              */
696             trace_colo_compare_main("packet different");
697             g_queue_push_head(&conn->primary_list, pkt);
698 
699             colo_compare_inconsistency_notify(s);
700             break;
701         }
702     }
703 }
704 
705 /*
706  * Called from the compare thread on the primary
707  * for compare packet with secondary list of the
708  * specified connection when a new packet was
709  * queued to it.
710  */
711 static void colo_compare_connection(void *opaque, void *user_data)
712 {
713     CompareState *s = user_data;
714     Connection *conn = opaque;
715 
716     switch (conn->ip_proto) {
717     case IPPROTO_TCP:
718         colo_compare_tcp(s, conn);
719         break;
720     case IPPROTO_UDP:
721         colo_compare_packet(s, conn, colo_packet_compare_udp);
722         break;
723     case IPPROTO_ICMP:
724         colo_compare_packet(s, conn, colo_packet_compare_icmp);
725         break;
726     default:
727         colo_compare_packet(s, conn, colo_packet_compare_other);
728         break;
729     }
730 }
731 
732 static void coroutine_fn _compare_chr_send(void *opaque)
733 {
734     SendCo *sendco = opaque;
735     CompareState *s = sendco->s;
736     int ret = 0;
737 
738     while (!g_queue_is_empty(&sendco->send_list)) {
739         SendEntry *entry = g_queue_pop_tail(&sendco->send_list);
740         uint32_t len = htonl(entry->size);
741 
742         ret = qemu_chr_fe_write_all(sendco->chr, (uint8_t *)&len, sizeof(len));
743 
744         if (ret != sizeof(len)) {
745             g_free(entry->buf);
746             g_slice_free(SendEntry, entry);
747             goto err;
748         }
749 
750         if (!sendco->notify_remote_frame && s->vnet_hdr) {
751             /*
752              * We send vnet header len make other module(like filter-redirector)
753              * know how to parse net packet correctly.
754              */
755             len = htonl(entry->vnet_hdr_len);
756 
757             ret = qemu_chr_fe_write_all(sendco->chr,
758                                         (uint8_t *)&len,
759                                         sizeof(len));
760 
761             if (ret != sizeof(len)) {
762                 g_free(entry->buf);
763                 g_slice_free(SendEntry, entry);
764                 goto err;
765             }
766         }
767 
768         ret = qemu_chr_fe_write_all(sendco->chr,
769                                     (uint8_t *)entry->buf,
770                                     entry->size);
771 
772         if (ret != entry->size) {
773             g_free(entry->buf);
774             g_slice_free(SendEntry, entry);
775             goto err;
776         }
777 
778         g_free(entry->buf);
779         g_slice_free(SendEntry, entry);
780     }
781 
782     sendco->ret = 0;
783     goto out;
784 
785 err:
786     while (!g_queue_is_empty(&sendco->send_list)) {
787         SendEntry *entry = g_queue_pop_tail(&sendco->send_list);
788         g_free(entry->buf);
789         g_slice_free(SendEntry, entry);
790     }
791     sendco->ret = ret < 0 ? ret : -EIO;
792 out:
793     sendco->co = NULL;
794     sendco->done = true;
795     aio_wait_kick();
796 }
797 
798 static int compare_chr_send(CompareState *s,
799                             uint8_t *buf,
800                             uint32_t size,
801                             uint32_t vnet_hdr_len,
802                             bool notify_remote_frame,
803                             bool zero_copy)
804 {
805     SendCo *sendco;
806     SendEntry *entry;
807 
808     if (notify_remote_frame) {
809         sendco = &s->notify_sendco;
810     } else {
811         sendco = &s->out_sendco;
812     }
813 
814     if (!size) {
815         return 0;
816     }
817 
818     entry = g_slice_new(SendEntry);
819     entry->size = size;
820     entry->vnet_hdr_len = vnet_hdr_len;
821     if (zero_copy) {
822         entry->buf = buf;
823     } else {
824         entry->buf = g_malloc(size);
825         memcpy(entry->buf, buf, size);
826     }
827     g_queue_push_head(&sendco->send_list, entry);
828 
829     if (sendco->done) {
830         sendco->co = qemu_coroutine_create(_compare_chr_send, sendco);
831         sendco->done = false;
832         qemu_coroutine_enter(sendco->co);
833         if (sendco->done) {
834             /* report early errors */
835             return sendco->ret;
836         }
837     }
838 
839     /* assume success */
840     return 0;
841 }
842 
843 static int compare_chr_can_read(void *opaque)
844 {
845     return COMPARE_READ_LEN_MAX;
846 }
847 
848 /*
849  * Called from the main thread on the primary for packets
850  * arriving over the socket from the primary.
851  */
852 static void compare_pri_chr_in(void *opaque, const uint8_t *buf, int size)
853 {
854     CompareState *s = COLO_COMPARE(opaque);
855     int ret;
856 
857     ret = net_fill_rstate(&s->pri_rs, buf, size);
858     if (ret == -1) {
859         qemu_chr_fe_set_handlers(&s->chr_pri_in, NULL, NULL, NULL, NULL,
860                                  NULL, NULL, true);
861         error_report("colo-compare primary_in error");
862     }
863 }
864 
865 /*
866  * Called from the main thread on the primary for packets
867  * arriving over the socket from the secondary.
868  */
869 static void compare_sec_chr_in(void *opaque, const uint8_t *buf, int size)
870 {
871     CompareState *s = COLO_COMPARE(opaque);
872     int ret;
873 
874     ret = net_fill_rstate(&s->sec_rs, buf, size);
875     if (ret == -1) {
876         qemu_chr_fe_set_handlers(&s->chr_sec_in, NULL, NULL, NULL, NULL,
877                                  NULL, NULL, true);
878         error_report("colo-compare secondary_in error");
879     }
880 }
881 
882 static void compare_notify_chr(void *opaque, const uint8_t *buf, int size)
883 {
884     CompareState *s = COLO_COMPARE(opaque);
885     int ret;
886 
887     ret = net_fill_rstate(&s->notify_rs, buf, size);
888     if (ret == -1) {
889         qemu_chr_fe_set_handlers(&s->chr_notify_dev, NULL, NULL, NULL, NULL,
890                                  NULL, NULL, true);
891         error_report("colo-compare notify_dev error");
892     }
893 }
894 
895 /*
896  * Check old packet regularly so it can watch for any packets
897  * that the secondary hasn't produced equivalents of.
898  */
899 static void check_old_packet_regular(void *opaque)
900 {
901     CompareState *s = opaque;
902 
903     /* if have old packet we will notify checkpoint */
904     colo_old_packet_check(s);
905     timer_mod(s->packet_check_timer, qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) +
906               s->expired_scan_cycle);
907 }
908 
909 /* Public API, Used for COLO frame to notify compare event */
910 void colo_notify_compares_event(void *opaque, int event, Error **errp)
911 {
912     CompareState *s;
913     qemu_mutex_lock(&colo_compare_mutex);
914 
915     if (!colo_compare_active) {
916         qemu_mutex_unlock(&colo_compare_mutex);
917         return;
918     }
919 
920     qemu_mutex_lock(&event_mtx);
921     QTAILQ_FOREACH(s, &net_compares, next) {
922         s->event = event;
923         qemu_bh_schedule(s->event_bh);
924         event_unhandled_count++;
925     }
926     /* Wait all compare threads to finish handling this event */
927     while (event_unhandled_count > 0) {
928         qemu_cond_wait(&event_complete_cond, &event_mtx);
929     }
930 
931     qemu_mutex_unlock(&event_mtx);
932     qemu_mutex_unlock(&colo_compare_mutex);
933 }
934 
935 static void colo_compare_timer_init(CompareState *s)
936 {
937     AioContext *ctx = iothread_get_aio_context(s->iothread);
938 
939     s->packet_check_timer = aio_timer_new(ctx, QEMU_CLOCK_VIRTUAL,
940                                 SCALE_MS, check_old_packet_regular,
941                                 s);
942     timer_mod(s->packet_check_timer, qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) +
943               s->expired_scan_cycle);
944 }
945 
946 static void colo_compare_timer_del(CompareState *s)
947 {
948     if (s->packet_check_timer) {
949         timer_del(s->packet_check_timer);
950         timer_free(s->packet_check_timer);
951         s->packet_check_timer = NULL;
952     }
953  }
954 
955 static void colo_flush_packets(void *opaque, void *user_data);
956 
957 static void colo_compare_handle_event(void *opaque)
958 {
959     CompareState *s = opaque;
960 
961     switch (s->event) {
962     case COLO_EVENT_CHECKPOINT:
963         g_queue_foreach(&s->conn_list, colo_flush_packets, s);
964         break;
965     case COLO_EVENT_FAILOVER:
966         break;
967     default:
968         break;
969     }
970 
971     qemu_mutex_lock(&event_mtx);
972     assert(event_unhandled_count > 0);
973     event_unhandled_count--;
974     qemu_cond_broadcast(&event_complete_cond);
975     qemu_mutex_unlock(&event_mtx);
976 }
977 
978 static void colo_compare_iothread(CompareState *s)
979 {
980     AioContext *ctx = iothread_get_aio_context(s->iothread);
981     object_ref(OBJECT(s->iothread));
982     s->worker_context = iothread_get_g_main_context(s->iothread);
983 
984     qemu_chr_fe_set_handlers(&s->chr_pri_in, compare_chr_can_read,
985                              compare_pri_chr_in, NULL, NULL,
986                              s, s->worker_context, true);
987     qemu_chr_fe_set_handlers(&s->chr_sec_in, compare_chr_can_read,
988                              compare_sec_chr_in, NULL, NULL,
989                              s, s->worker_context, true);
990     if (s->notify_dev) {
991         qemu_chr_fe_set_handlers(&s->chr_notify_dev, compare_chr_can_read,
992                                  compare_notify_chr, NULL, NULL,
993                                  s, s->worker_context, true);
994     }
995 
996     colo_compare_timer_init(s);
997     s->event_bh = aio_bh_new(ctx, colo_compare_handle_event, s);
998 }
999 
1000 static char *compare_get_pri_indev(Object *obj, Error **errp)
1001 {
1002     CompareState *s = COLO_COMPARE(obj);
1003 
1004     return g_strdup(s->pri_indev);
1005 }
1006 
1007 static void compare_set_pri_indev(Object *obj, const char *value, Error **errp)
1008 {
1009     CompareState *s = COLO_COMPARE(obj);
1010 
1011     g_free(s->pri_indev);
1012     s->pri_indev = g_strdup(value);
1013 }
1014 
1015 static char *compare_get_sec_indev(Object *obj, Error **errp)
1016 {
1017     CompareState *s = COLO_COMPARE(obj);
1018 
1019     return g_strdup(s->sec_indev);
1020 }
1021 
1022 static void compare_set_sec_indev(Object *obj, const char *value, Error **errp)
1023 {
1024     CompareState *s = COLO_COMPARE(obj);
1025 
1026     g_free(s->sec_indev);
1027     s->sec_indev = g_strdup(value);
1028 }
1029 
1030 static char *compare_get_outdev(Object *obj, Error **errp)
1031 {
1032     CompareState *s = COLO_COMPARE(obj);
1033 
1034     return g_strdup(s->outdev);
1035 }
1036 
1037 static void compare_set_outdev(Object *obj, const char *value, Error **errp)
1038 {
1039     CompareState *s = COLO_COMPARE(obj);
1040 
1041     g_free(s->outdev);
1042     s->outdev = g_strdup(value);
1043 }
1044 
1045 static bool compare_get_vnet_hdr(Object *obj, Error **errp)
1046 {
1047     CompareState *s = COLO_COMPARE(obj);
1048 
1049     return s->vnet_hdr;
1050 }
1051 
1052 static void compare_set_vnet_hdr(Object *obj,
1053                                  bool value,
1054                                  Error **errp)
1055 {
1056     CompareState *s = COLO_COMPARE(obj);
1057 
1058     s->vnet_hdr = value;
1059 }
1060 
1061 static char *compare_get_notify_dev(Object *obj, Error **errp)
1062 {
1063     CompareState *s = COLO_COMPARE(obj);
1064 
1065     return g_strdup(s->notify_dev);
1066 }
1067 
1068 static void compare_set_notify_dev(Object *obj, const char *value, Error **errp)
1069 {
1070     CompareState *s = COLO_COMPARE(obj);
1071 
1072     g_free(s->notify_dev);
1073     s->notify_dev = g_strdup(value);
1074 }
1075 
1076 static void compare_get_timeout(Object *obj, Visitor *v,
1077                                 const char *name, void *opaque,
1078                                 Error **errp)
1079 {
1080     CompareState *s = COLO_COMPARE(obj);
1081     uint32_t value = s->compare_timeout;
1082 
1083     visit_type_uint32(v, name, &value, errp);
1084 }
1085 
1086 static void compare_set_timeout(Object *obj, Visitor *v,
1087                                 const char *name, void *opaque,
1088                                 Error **errp)
1089 {
1090     CompareState *s = COLO_COMPARE(obj);
1091     uint32_t value;
1092 
1093     if (!visit_type_uint32(v, name, &value, errp)) {
1094         return;
1095     }
1096     if (!value) {
1097         error_setg(errp, "Property '%s.%s' requires a positive value",
1098                    object_get_typename(obj), name);
1099         return;
1100     }
1101     s->compare_timeout = value;
1102 }
1103 
1104 static void compare_get_expired_scan_cycle(Object *obj, Visitor *v,
1105                                            const char *name, void *opaque,
1106                                            Error **errp)
1107 {
1108     CompareState *s = COLO_COMPARE(obj);
1109     uint32_t value = s->expired_scan_cycle;
1110 
1111     visit_type_uint32(v, name, &value, errp);
1112 }
1113 
1114 static void compare_set_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;
1120 
1121     if (!visit_type_uint32(v, name, &value, errp)) {
1122         return;
1123     }
1124     if (!value) {
1125         error_setg(errp, "Property '%s.%s' requires a positive value",
1126                    object_get_typename(obj), name);
1127         return;
1128     }
1129     s->expired_scan_cycle = value;
1130 }
1131 
1132 static void get_max_queue_size(Object *obj, Visitor *v,
1133                                const char *name, void *opaque,
1134                                Error **errp)
1135 {
1136     uint32_t value = max_queue_size;
1137 
1138     visit_type_uint32(v, name, &value, errp);
1139 }
1140 
1141 static void set_max_queue_size(Object *obj, Visitor *v,
1142                                const char *name, void *opaque,
1143                                Error **errp)
1144 {
1145     Error *local_err = NULL;
1146     uint32_t value;
1147 
1148     visit_type_uint32(v, name, &value, &local_err);
1149     if (local_err) {
1150         goto out;
1151     }
1152     if (!value) {
1153         error_setg(&local_err, "Property '%s.%s' requires a positive value",
1154                    object_get_typename(obj), name);
1155         goto out;
1156     }
1157     max_queue_size = value;
1158 
1159 out:
1160     error_propagate(errp, local_err);
1161 }
1162 
1163 static void compare_pri_rs_finalize(SocketReadState *pri_rs)
1164 {
1165     CompareState *s = container_of(pri_rs, CompareState, pri_rs);
1166     Connection *conn = NULL;
1167 
1168     if (packet_enqueue(s, PRIMARY_IN, &conn)) {
1169         trace_colo_compare_main("primary: unsupported packet in");
1170         compare_chr_send(s,
1171                          pri_rs->buf,
1172                          pri_rs->packet_len,
1173                          pri_rs->vnet_hdr_len,
1174                          false,
1175                          false);
1176     } else {
1177         /* compare packet in the specified connection */
1178         colo_compare_connection(conn, s);
1179     }
1180 }
1181 
1182 static void compare_sec_rs_finalize(SocketReadState *sec_rs)
1183 {
1184     CompareState *s = container_of(sec_rs, CompareState, sec_rs);
1185     Connection *conn = NULL;
1186 
1187     if (packet_enqueue(s, SECONDARY_IN, &conn)) {
1188         trace_colo_compare_main("secondary: unsupported packet in");
1189     } else {
1190         /* compare packet in the specified connection */
1191         colo_compare_connection(conn, s);
1192     }
1193 }
1194 
1195 static void compare_notify_rs_finalize(SocketReadState *notify_rs)
1196 {
1197     CompareState *s = container_of(notify_rs, CompareState, notify_rs);
1198 
1199     const char msg[] = "COLO_COMPARE_GET_XEN_INIT";
1200     int ret;
1201 
1202     if (packet_matches_str("COLO_USERSPACE_PROXY_INIT",
1203                            notify_rs->buf,
1204                            notify_rs->packet_len)) {
1205         ret = compare_chr_send(s, (uint8_t *)msg, strlen(msg), 0, true, false);
1206         if (ret < 0) {
1207             error_report("Notify Xen COLO-frame INIT failed");
1208         }
1209     } else if (packet_matches_str("COLO_CHECKPOINT",
1210                                   notify_rs->buf,
1211                                   notify_rs->packet_len)) {
1212         /* colo-compare do checkpoint, flush pri packet and remove sec packet */
1213         g_queue_foreach(&s->conn_list, colo_flush_packets, s);
1214     } else {
1215         error_report("COLO compare got unsupported instruction");
1216     }
1217 }
1218 
1219 /*
1220  * Return 0 is success.
1221  * Return 1 is failed.
1222  */
1223 static int find_and_check_chardev(Chardev **chr,
1224                                   char *chr_name,
1225                                   Error **errp)
1226 {
1227     *chr = qemu_chr_find(chr_name);
1228     if (*chr == NULL) {
1229         error_setg(errp, "Device '%s' not found",
1230                    chr_name);
1231         return 1;
1232     }
1233 
1234     if (!qemu_chr_has_feature(*chr, QEMU_CHAR_FEATURE_RECONNECTABLE)) {
1235         error_setg(errp, "chardev \"%s\" is not reconnectable",
1236                    chr_name);
1237         return 1;
1238     }
1239 
1240     if (!qemu_chr_has_feature(*chr, QEMU_CHAR_FEATURE_GCONTEXT)) {
1241         error_setg(errp, "chardev \"%s\" cannot switch context",
1242                    chr_name);
1243         return 1;
1244     }
1245 
1246     return 0;
1247 }
1248 
1249 /*
1250  * Called from the main thread on the primary
1251  * to setup colo-compare.
1252  */
1253 static void colo_compare_complete(UserCreatable *uc, Error **errp)
1254 {
1255     CompareState *s = COLO_COMPARE(uc);
1256     Chardev *chr;
1257 
1258     if (!s->pri_indev || !s->sec_indev || !s->outdev || !s->iothread) {
1259         error_setg(errp, "colo compare needs 'primary_in' ,"
1260                    "'secondary_in','outdev','iothread' property set");
1261         return;
1262     } else if (!strcmp(s->pri_indev, s->outdev) ||
1263                !strcmp(s->sec_indev, s->outdev) ||
1264                !strcmp(s->pri_indev, s->sec_indev)) {
1265         error_setg(errp, "'indev' and 'outdev' could not be same "
1266                    "for compare module");
1267         return;
1268     }
1269 
1270     if (!s->compare_timeout) {
1271         /* Set default value to 3000 MS */
1272         s->compare_timeout = DEFAULT_TIME_OUT_MS;
1273     }
1274 
1275     if (!s->expired_scan_cycle) {
1276         /* Set default value to 3000 MS */
1277         s->expired_scan_cycle = REGULAR_PACKET_CHECK_MS;
1278     }
1279 
1280     if (!max_queue_size) {
1281         /* Set default queue size to 1024 */
1282         max_queue_size = MAX_QUEUE_SIZE;
1283     }
1284 
1285     if (find_and_check_chardev(&chr, s->pri_indev, errp) ||
1286         !qemu_chr_fe_init(&s->chr_pri_in, chr, errp)) {
1287         return;
1288     }
1289 
1290     if (find_and_check_chardev(&chr, s->sec_indev, errp) ||
1291         !qemu_chr_fe_init(&s->chr_sec_in, chr, errp)) {
1292         return;
1293     }
1294 
1295     if (find_and_check_chardev(&chr, s->outdev, errp) ||
1296         !qemu_chr_fe_init(&s->chr_out, chr, errp)) {
1297         return;
1298     }
1299 
1300     net_socket_rs_init(&s->pri_rs, compare_pri_rs_finalize, s->vnet_hdr);
1301     net_socket_rs_init(&s->sec_rs, compare_sec_rs_finalize, s->vnet_hdr);
1302 
1303     /* Try to enable remote notify chardev, currently just for Xen COLO */
1304     if (s->notify_dev) {
1305         if (find_and_check_chardev(&chr, s->notify_dev, errp) ||
1306             !qemu_chr_fe_init(&s->chr_notify_dev, chr, errp)) {
1307             return;
1308         }
1309 
1310         net_socket_rs_init(&s->notify_rs, compare_notify_rs_finalize,
1311                            s->vnet_hdr);
1312     }
1313 
1314     s->out_sendco.s = s;
1315     s->out_sendco.chr = &s->chr_out;
1316     s->out_sendco.notify_remote_frame = false;
1317     s->out_sendco.done = true;
1318     g_queue_init(&s->out_sendco.send_list);
1319 
1320     if (s->notify_dev) {
1321         s->notify_sendco.s = s;
1322         s->notify_sendco.chr = &s->chr_notify_dev;
1323         s->notify_sendco.notify_remote_frame = true;
1324         s->notify_sendco.done = true;
1325         g_queue_init(&s->notify_sendco.send_list);
1326     }
1327 
1328     g_queue_init(&s->conn_list);
1329 
1330     s->connection_track_table = g_hash_table_new_full(connection_key_hash,
1331                                                       connection_key_equal,
1332                                                       g_free,
1333                                                       connection_destroy);
1334 
1335     colo_compare_iothread(s);
1336 
1337     qemu_mutex_lock(&colo_compare_mutex);
1338     if (!colo_compare_active) {
1339         qemu_mutex_init(&event_mtx);
1340         qemu_cond_init(&event_complete_cond);
1341         colo_compare_active = true;
1342     }
1343     QTAILQ_INSERT_TAIL(&net_compares, s, next);
1344     qemu_mutex_unlock(&colo_compare_mutex);
1345 
1346     return;
1347 }
1348 
1349 static void colo_flush_packets(void *opaque, void *user_data)
1350 {
1351     CompareState *s = user_data;
1352     Connection *conn = opaque;
1353     Packet *pkt = NULL;
1354 
1355     while (!g_queue_is_empty(&conn->primary_list)) {
1356         pkt = g_queue_pop_head(&conn->primary_list);
1357         compare_chr_send(s,
1358                          pkt->data,
1359                          pkt->size,
1360                          pkt->vnet_hdr_len,
1361                          false,
1362                          true);
1363         packet_destroy_partial(pkt, NULL);
1364     }
1365     while (!g_queue_is_empty(&conn->secondary_list)) {
1366         pkt = g_queue_pop_head(&conn->secondary_list);
1367         packet_destroy(pkt, NULL);
1368     }
1369 }
1370 
1371 static void colo_compare_class_init(ObjectClass *oc, void *data)
1372 {
1373     UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);
1374 
1375     ucc->complete = colo_compare_complete;
1376 }
1377 
1378 static void colo_compare_init(Object *obj)
1379 {
1380     CompareState *s = COLO_COMPARE(obj);
1381 
1382     object_property_add_str(obj, "primary_in",
1383                             compare_get_pri_indev, compare_set_pri_indev);
1384     object_property_add_str(obj, "secondary_in",
1385                             compare_get_sec_indev, compare_set_sec_indev);
1386     object_property_add_str(obj, "outdev",
1387                             compare_get_outdev, compare_set_outdev);
1388     object_property_add_link(obj, "iothread", TYPE_IOTHREAD,
1389                             (Object **)&s->iothread,
1390                             object_property_allow_set_link,
1391                             OBJ_PROP_LINK_STRONG);
1392     /* This parameter just for Xen COLO */
1393     object_property_add_str(obj, "notify_dev",
1394                             compare_get_notify_dev, compare_set_notify_dev);
1395 
1396     object_property_add(obj, "compare_timeout", "uint32",
1397                         compare_get_timeout,
1398                         compare_set_timeout, NULL, NULL);
1399 
1400     object_property_add(obj, "expired_scan_cycle", "uint32",
1401                         compare_get_expired_scan_cycle,
1402                         compare_set_expired_scan_cycle, NULL, NULL);
1403 
1404     object_property_add(obj, "max_queue_size", "uint32",
1405                         get_max_queue_size,
1406                         set_max_queue_size, NULL, NULL);
1407 
1408     s->vnet_hdr = false;
1409     object_property_add_bool(obj, "vnet_hdr_support", compare_get_vnet_hdr,
1410                              compare_set_vnet_hdr);
1411 }
1412 
1413 static void colo_compare_finalize(Object *obj)
1414 {
1415     CompareState *s = COLO_COMPARE(obj);
1416     CompareState *tmp = NULL;
1417 
1418     qemu_mutex_lock(&colo_compare_mutex);
1419     QTAILQ_FOREACH(tmp, &net_compares, next) {
1420         if (tmp == s) {
1421             QTAILQ_REMOVE(&net_compares, s, next);
1422             break;
1423         }
1424     }
1425     if (QTAILQ_EMPTY(&net_compares)) {
1426         colo_compare_active = false;
1427         qemu_mutex_destroy(&event_mtx);
1428         qemu_cond_destroy(&event_complete_cond);
1429     }
1430     qemu_mutex_unlock(&colo_compare_mutex);
1431 
1432     qemu_chr_fe_deinit(&s->chr_pri_in, false);
1433     qemu_chr_fe_deinit(&s->chr_sec_in, false);
1434     qemu_chr_fe_deinit(&s->chr_out, false);
1435     if (s->notify_dev) {
1436         qemu_chr_fe_deinit(&s->chr_notify_dev, false);
1437     }
1438 
1439     colo_compare_timer_del(s);
1440 
1441     qemu_bh_delete(s->event_bh);
1442 
1443     AioContext *ctx = iothread_get_aio_context(s->iothread);
1444     aio_context_acquire(ctx);
1445     AIO_WAIT_WHILE(ctx, !s->out_sendco.done);
1446     if (s->notify_dev) {
1447         AIO_WAIT_WHILE(ctx, !s->notify_sendco.done);
1448     }
1449     aio_context_release(ctx);
1450 
1451     /* Release all unhandled packets after compare thead exited */
1452     g_queue_foreach(&s->conn_list, colo_flush_packets, s);
1453     AIO_WAIT_WHILE(NULL, !s->out_sendco.done);
1454 
1455     g_queue_clear(&s->conn_list);
1456     g_queue_clear(&s->out_sendco.send_list);
1457     if (s->notify_dev) {
1458         g_queue_clear(&s->notify_sendco.send_list);
1459     }
1460 
1461     if (s->connection_track_table) {
1462         g_hash_table_destroy(s->connection_track_table);
1463     }
1464 
1465     object_unref(OBJECT(s->iothread));
1466 
1467     g_free(s->pri_indev);
1468     g_free(s->sec_indev);
1469     g_free(s->outdev);
1470     g_free(s->notify_dev);
1471 }
1472 
1473 static void __attribute__((__constructor__)) colo_compare_init_globals(void)
1474 {
1475     colo_compare_active = false;
1476     qemu_mutex_init(&colo_compare_mutex);
1477 }
1478 
1479 static const TypeInfo colo_compare_info = {
1480     .name = TYPE_COLO_COMPARE,
1481     .parent = TYPE_OBJECT,
1482     .instance_size = sizeof(CompareState),
1483     .instance_init = colo_compare_init,
1484     .instance_finalize = colo_compare_finalize,
1485     .class_size = sizeof(CompareClass),
1486     .class_init = colo_compare_class_init,
1487     .interfaces = (InterfaceInfo[]) {
1488         { TYPE_USER_CREATABLE },
1489         { }
1490     }
1491 };
1492 
1493 static void register_types(void)
1494 {
1495     type_register_static(&colo_compare_info);
1496 }
1497 
1498 type_init(register_types);
1499