xref: /openbmc/qemu/net/colo-compare.c (revision eabfeb0c)
1 /*
2  * COarse-grain LOck-stepping Virtual Machines for Non-stop Service (COLO)
3  * (a.k.a. Fault Tolerance or Continuous Replication)
4  *
5  * Copyright (c) 2016 HUAWEI TECHNOLOGIES CO., LTD.
6  * Copyright (c) 2016 FUJITSU LIMITED
7  * Copyright (c) 2016 Intel Corporation
8  *
9  * Author: Zhang Chen <zhangchen.fnst@cn.fujitsu.com>
10  *
11  * This work is licensed under the terms of the GNU GPL, version 2 or
12  * later.  See the COPYING file in the top-level directory.
13  */
14 
15 #include "qemu/osdep.h"
16 #include "qemu-common.h"
17 #include "qemu/error-report.h"
18 #include "trace.h"
19 #include "qapi/error.h"
20 #include "net/net.h"
21 #include "net/eth.h"
22 #include "qom/object_interfaces.h"
23 #include "qemu/iov.h"
24 #include "qom/object.h"
25 #include "net/queue.h"
26 #include "chardev/char-fe.h"
27 #include "qemu/sockets.h"
28 #include "colo.h"
29 #include "sysemu/iothread.h"
30 #include "net/colo-compare.h"
31 #include "migration/colo.h"
32 #include "migration/migration.h"
33 #include "util.h"
34 
35 #include "block/aio-wait.h"
36 #include "qemu/coroutine.h"
37 
38 #define TYPE_COLO_COMPARE "colo-compare"
39 #define COLO_COMPARE(obj) \
40     OBJECT_CHECK(CompareState, (obj), TYPE_COLO_COMPARE)
41 
42 static QTAILQ_HEAD(, CompareState) net_compares =
43        QTAILQ_HEAD_INITIALIZER(net_compares);
44 
45 static NotifierList colo_compare_notifiers =
46     NOTIFIER_LIST_INITIALIZER(colo_compare_notifiers);
47 
48 #define COMPARE_READ_LEN_MAX NET_BUFSIZE
49 #define MAX_QUEUE_SIZE 1024
50 
51 #define COLO_COMPARE_FREE_PRIMARY     0x01
52 #define COLO_COMPARE_FREE_SECONDARY   0x02
53 
54 #define REGULAR_PACKET_CHECK_MS 3000
55 #define DEFAULT_TIME_OUT_MS 3000
56 
57 static QemuMutex colo_compare_mutex;
58 static bool colo_compare_active;
59 static QemuMutex event_mtx;
60 static QemuCond event_complete_cond;
61 static int event_unhandled_count;
62 static uint32_t max_queue_size;
63 
64 /*
65  *  + CompareState ++
66  *  |               |
67  *  +---------------+   +---------------+         +---------------+
68  *  |   conn list   + - >      conn     + ------- >      conn     + -- > ......
69  *  +---------------+   +---------------+         +---------------+
70  *  |               |     |           |             |          |
71  *  +---------------+ +---v----+  +---v----+    +---v----+ +---v----+
72  *                    |primary |  |secondary    |primary | |secondary
73  *                    |packet  |  |packet  +    |packet  | |packet  +
74  *                    +--------+  +--------+    +--------+ +--------+
75  *                        |           |             |          |
76  *                    +---v----+  +---v----+    +---v----+ +---v----+
77  *                    |primary |  |secondary    |primary | |secondary
78  *                    |packet  |  |packet  +    |packet  | |packet  +
79  *                    +--------+  +--------+    +--------+ +--------+
80  *                        |           |             |          |
81  *                    +---v----+  +---v----+    +---v----+ +---v----+
82  *                    |primary |  |secondary    |primary | |secondary
83  *                    |packet  |  |packet  +    |packet  | |packet  +
84  *                    +--------+  +--------+    +--------+ +--------+
85  */
86 
87 typedef struct SendCo {
88     Coroutine *co;
89     struct CompareState *s;
90     CharBackend *chr;
91     GQueue send_list;
92     bool notify_remote_frame;
93     bool done;
94     int ret;
95 } SendCo;
96 
97 typedef struct SendEntry {
98     uint32_t size;
99     uint32_t vnet_hdr_len;
100     uint8_t *buf;
101 } SendEntry;
102 
103 typedef struct CompareState {
104     Object parent;
105 
106     char *pri_indev;
107     char *sec_indev;
108     char *outdev;
109     char *notify_dev;
110     CharBackend chr_pri_in;
111     CharBackend chr_sec_in;
112     CharBackend chr_out;
113     CharBackend chr_notify_dev;
114     SocketReadState pri_rs;
115     SocketReadState sec_rs;
116     SocketReadState notify_rs;
117     SendCo out_sendco;
118     SendCo notify_sendco;
119     bool vnet_hdr;
120     uint32_t compare_timeout;
121     uint32_t expired_scan_cycle;
122 
123     /*
124      * Record the connection that through the NIC
125      * Element type: Connection
126      */
127     GQueue conn_list;
128     /* Record the connection without repetition */
129     GHashTable *connection_track_table;
130 
131     IOThread *iothread;
132     GMainContext *worker_context;
133     QEMUTimer *packet_check_timer;
134 
135     QEMUBH *event_bh;
136     enum colo_event event;
137 
138     QTAILQ_ENTRY(CompareState) next;
139 } CompareState;
140 
141 typedef struct CompareClass {
142     ObjectClass parent_class;
143 } CompareClass;
144 
145 enum {
146     PRIMARY_IN = 0,
147     SECONDARY_IN,
148 };
149 
150 static const char *colo_mode[] = {
151     [PRIMARY_IN] = "primary",
152     [SECONDARY_IN] = "secondary",
153 };
154 
155 static int compare_chr_send(CompareState *s,
156                             uint8_t *buf,
157                             uint32_t size,
158                             uint32_t vnet_hdr_len,
159                             bool notify_remote_frame,
160                             bool zero_copy);
161 
162 static bool packet_matches_str(const char *str,
163                                const uint8_t *buf,
164                                uint32_t packet_len)
165 {
166     if (packet_len != strlen(str)) {
167         return false;
168     }
169 
170     return !memcmp(str, buf, strlen(str));
171 }
172 
173 static void notify_remote_frame(CompareState *s)
174 {
175     char msg[] = "DO_CHECKPOINT";
176     int ret = 0;
177 
178     ret = compare_chr_send(s, (uint8_t *)msg, strlen(msg), 0, true, false);
179     if (ret < 0) {
180         error_report("Notify Xen COLO-frame failed");
181     }
182 }
183 
184 static void colo_compare_inconsistency_notify(CompareState *s)
185 {
186     if (s->notify_dev) {
187         notify_remote_frame(s);
188     } else {
189         notifier_list_notify(&colo_compare_notifiers,
190                              migrate_get_current());
191     }
192 }
193 
194 static gint seq_sorter(Packet *a, Packet *b, gpointer data)
195 {
196     struct tcp_hdr *atcp, *btcp;
197 
198     atcp = (struct tcp_hdr *)(a->transport_header);
199     btcp = (struct tcp_hdr *)(b->transport_header);
200     return ntohl(atcp->th_seq) - ntohl(btcp->th_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_MISCOMPARE)) {
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         if (trace_event_get_state_backends(TRACE_COLO_COMPARE_MISCOMPARE)) {
497             qemu_hexdump((char *)ppkt->data, stderr,
498                         "colo-compare ppkt", ppkt->size);
499             qemu_hexdump((char *)spkt->data, stderr,
500                         "colo-compare spkt", spkt->size);
501         }
502 
503         colo_compare_inconsistency_notify(s);
504     }
505 }
506 
507 
508 /*
509  * Called from the compare thread on the primary
510  * for compare udp packet
511  */
512 static int colo_packet_compare_udp(Packet *spkt, Packet *ppkt)
513 {
514     uint16_t network_header_length = ppkt->ip->ip_hl << 2;
515     uint16_t offset = network_header_length + ETH_HLEN + ppkt->vnet_hdr_len;
516 
517     trace_colo_compare_main("compare udp");
518 
519     /*
520      * Because of ppkt and spkt are both in the same connection,
521      * The ppkt's src ip, dst ip, src port, dst port, ip_proto all are
522      * same with spkt. In addition, IP header's Identification is a random
523      * field, we can handle it in IP fragmentation function later.
524      * COLO just concern the response net packet payload from primary guest
525      * and secondary guest are same or not, So we ignored all IP header include
526      * other field like TOS,TTL,IP Checksum. we only need to compare
527      * the ip payload here.
528      */
529     if (ppkt->size != spkt->size) {
530         trace_colo_compare_main("UDP: payload size of packets are different");
531         return -1;
532     }
533     if (colo_compare_packet_payload(ppkt, spkt, offset, offset,
534                                     ppkt->size - offset)) {
535         trace_colo_compare_udp_miscompare("primary pkt size", ppkt->size);
536         trace_colo_compare_udp_miscompare("Secondary pkt size", spkt->size);
537         if (trace_event_get_state_backends(TRACE_COLO_COMPARE_MISCOMPARE)) {
538             qemu_hexdump((char *)ppkt->data, stderr, "colo-compare pri pkt",
539                          ppkt->size);
540             qemu_hexdump((char *)spkt->data, stderr, "colo-compare sec pkt",
541                          spkt->size);
542         }
543         return -1;
544     } else {
545         return 0;
546     }
547 }
548 
549 /*
550  * Called from the compare thread on the primary
551  * for compare icmp packet
552  */
553 static int colo_packet_compare_icmp(Packet *spkt, Packet *ppkt)
554 {
555     uint16_t network_header_length = ppkt->ip->ip_hl << 2;
556     uint16_t offset = network_header_length + ETH_HLEN + ppkt->vnet_hdr_len;
557 
558     trace_colo_compare_main("compare icmp");
559 
560     /*
561      * Because of ppkt and spkt are both in the same connection,
562      * The ppkt's src ip, dst ip, src port, dst port, ip_proto all are
563      * same with spkt. In addition, IP header's Identification is a random
564      * field, we can handle it in IP fragmentation function later.
565      * COLO just concern the response net packet payload from primary guest
566      * and secondary guest are same or not, So we ignored all IP header include
567      * other field like TOS,TTL,IP Checksum. we only need to compare
568      * the ip payload here.
569      */
570     if (ppkt->size != spkt->size) {
571         trace_colo_compare_main("ICMP: payload size of packets are different");
572         return -1;
573     }
574     if (colo_compare_packet_payload(ppkt, spkt, offset, offset,
575                                     ppkt->size - offset)) {
576         trace_colo_compare_icmp_miscompare("primary pkt size",
577                                            ppkt->size);
578         trace_colo_compare_icmp_miscompare("Secondary pkt size",
579                                            spkt->size);
580         if (trace_event_get_state_backends(TRACE_COLO_COMPARE_MISCOMPARE)) {
581             qemu_hexdump((char *)ppkt->data, stderr, "colo-compare pri pkt",
582                          ppkt->size);
583             qemu_hexdump((char *)spkt->data, stderr, "colo-compare sec pkt",
584                          spkt->size);
585         }
586         return -1;
587     } else {
588         return 0;
589     }
590 }
591 
592 /*
593  * Called from the compare thread on the primary
594  * for compare other packet
595  */
596 static int colo_packet_compare_other(Packet *spkt, Packet *ppkt)
597 {
598     uint16_t offset = ppkt->vnet_hdr_len;
599 
600     trace_colo_compare_main("compare other");
601     if (trace_event_get_state_backends(TRACE_COLO_COMPARE_MISCOMPARE)) {
602         char pri_ip_src[20], pri_ip_dst[20], sec_ip_src[20], sec_ip_dst[20];
603 
604         strcpy(pri_ip_src, inet_ntoa(ppkt->ip->ip_src));
605         strcpy(pri_ip_dst, inet_ntoa(ppkt->ip->ip_dst));
606         strcpy(sec_ip_src, inet_ntoa(spkt->ip->ip_src));
607         strcpy(sec_ip_dst, inet_ntoa(spkt->ip->ip_dst));
608 
609         trace_colo_compare_ip_info(ppkt->size, pri_ip_src,
610                                    pri_ip_dst, spkt->size,
611                                    sec_ip_src, sec_ip_dst);
612     }
613 
614     if (ppkt->size != spkt->size) {
615         trace_colo_compare_main("Other: payload size of packets are different");
616         return -1;
617     }
618     return colo_compare_packet_payload(ppkt, spkt, offset, offset,
619                                        ppkt->size - offset);
620 }
621 
622 static int colo_old_packet_check_one(Packet *pkt, int64_t *check_time)
623 {
624     int64_t now = qemu_clock_get_ms(QEMU_CLOCK_HOST);
625 
626     if ((now - pkt->creation_ms) > (*check_time)) {
627         trace_colo_old_packet_check_found(pkt->creation_ms);
628         return 0;
629     } else {
630         return 1;
631     }
632 }
633 
634 void colo_compare_register_notifier(Notifier *notify)
635 {
636     notifier_list_add(&colo_compare_notifiers, notify);
637 }
638 
639 void colo_compare_unregister_notifier(Notifier *notify)
640 {
641     notifier_remove(notify);
642 }
643 
644 static int colo_old_packet_check_one_conn(Connection *conn,
645                                           CompareState *s)
646 {
647     GList *result = NULL;
648 
649     result = g_queue_find_custom(&conn->primary_list,
650                                  &s->compare_timeout,
651                                  (GCompareFunc)colo_old_packet_check_one);
652 
653     if (result) {
654         /* Do checkpoint will flush old packet */
655         colo_compare_inconsistency_notify(s);
656         return 0;
657     }
658 
659     return 1;
660 }
661 
662 /*
663  * Look for old packets that the secondary hasn't matched,
664  * if we have some then we have to checkpoint to wake
665  * the secondary up.
666  */
667 static void colo_old_packet_check(void *opaque)
668 {
669     CompareState *s = opaque;
670 
671     /*
672      * If we find one old packet, stop finding job and notify
673      * COLO frame do checkpoint.
674      */
675     g_queue_find_custom(&s->conn_list, s,
676                         (GCompareFunc)colo_old_packet_check_one_conn);
677 }
678 
679 static void colo_compare_packet(CompareState *s, Connection *conn,
680                                 int (*HandlePacket)(Packet *spkt,
681                                 Packet *ppkt))
682 {
683     Packet *pkt = NULL;
684     GList *result = NULL;
685 
686     while (!g_queue_is_empty(&conn->primary_list) &&
687            !g_queue_is_empty(&conn->secondary_list)) {
688         pkt = g_queue_pop_head(&conn->primary_list);
689         result = g_queue_find_custom(&conn->secondary_list,
690                  pkt, (GCompareFunc)HandlePacket);
691 
692         if (result) {
693             colo_release_primary_pkt(s, pkt);
694             g_queue_remove(&conn->secondary_list, result->data);
695         } else {
696             /*
697              * If one packet arrive late, the secondary_list or
698              * primary_list will be empty, so we can't compare it
699              * until next comparison. If the packets in the list are
700              * timeout, it will trigger a checkpoint request.
701              */
702             trace_colo_compare_main("packet different");
703             g_queue_push_head(&conn->primary_list, pkt);
704 
705             colo_compare_inconsistency_notify(s);
706             break;
707         }
708     }
709 }
710 
711 /*
712  * Called from the compare thread on the primary
713  * for compare packet with secondary list of the
714  * specified connection when a new packet was
715  * queued to it.
716  */
717 static void colo_compare_connection(void *opaque, void *user_data)
718 {
719     CompareState *s = user_data;
720     Connection *conn = opaque;
721 
722     switch (conn->ip_proto) {
723     case IPPROTO_TCP:
724         colo_compare_tcp(s, conn);
725         break;
726     case IPPROTO_UDP:
727         colo_compare_packet(s, conn, colo_packet_compare_udp);
728         break;
729     case IPPROTO_ICMP:
730         colo_compare_packet(s, conn, colo_packet_compare_icmp);
731         break;
732     default:
733         colo_compare_packet(s, conn, colo_packet_compare_other);
734         break;
735     }
736 }
737 
738 static void coroutine_fn _compare_chr_send(void *opaque)
739 {
740     SendCo *sendco = opaque;
741     CompareState *s = sendco->s;
742     int ret = 0;
743 
744     while (!g_queue_is_empty(&sendco->send_list)) {
745         SendEntry *entry = g_queue_pop_tail(&sendco->send_list);
746         uint32_t len = htonl(entry->size);
747 
748         ret = qemu_chr_fe_write_all(sendco->chr, (uint8_t *)&len, sizeof(len));
749 
750         if (ret != sizeof(len)) {
751             g_free(entry->buf);
752             g_slice_free(SendEntry, entry);
753             goto err;
754         }
755 
756         if (!sendco->notify_remote_frame && s->vnet_hdr) {
757             /*
758              * We send vnet header len make other module(like filter-redirector)
759              * know how to parse net packet correctly.
760              */
761             len = htonl(entry->vnet_hdr_len);
762 
763             ret = qemu_chr_fe_write_all(sendco->chr,
764                                         (uint8_t *)&len,
765                                         sizeof(len));
766 
767             if (ret != sizeof(len)) {
768                 g_free(entry->buf);
769                 g_slice_free(SendEntry, entry);
770                 goto err;
771             }
772         }
773 
774         ret = qemu_chr_fe_write_all(sendco->chr,
775                                     (uint8_t *)entry->buf,
776                                     entry->size);
777 
778         if (ret != entry->size) {
779             g_free(entry->buf);
780             g_slice_free(SendEntry, entry);
781             goto err;
782         }
783 
784         g_free(entry->buf);
785         g_slice_free(SendEntry, entry);
786     }
787 
788     sendco->ret = 0;
789     goto out;
790 
791 err:
792     while (!g_queue_is_empty(&sendco->send_list)) {
793         SendEntry *entry = g_queue_pop_tail(&sendco->send_list);
794         g_free(entry->buf);
795         g_slice_free(SendEntry, entry);
796     }
797     sendco->ret = ret < 0 ? ret : -EIO;
798 out:
799     sendco->co = NULL;
800     sendco->done = true;
801     aio_wait_kick();
802 }
803 
804 static int compare_chr_send(CompareState *s,
805                             uint8_t *buf,
806                             uint32_t size,
807                             uint32_t vnet_hdr_len,
808                             bool notify_remote_frame,
809                             bool zero_copy)
810 {
811     SendCo *sendco;
812     SendEntry *entry;
813 
814     if (notify_remote_frame) {
815         sendco = &s->notify_sendco;
816     } else {
817         sendco = &s->out_sendco;
818     }
819 
820     if (!size) {
821         return 0;
822     }
823 
824     entry = g_slice_new(SendEntry);
825     entry->size = size;
826     entry->vnet_hdr_len = vnet_hdr_len;
827     if (zero_copy) {
828         entry->buf = buf;
829     } else {
830         entry->buf = g_malloc(size);
831         memcpy(entry->buf, buf, size);
832     }
833     g_queue_push_head(&sendco->send_list, entry);
834 
835     if (sendco->done) {
836         sendco->co = qemu_coroutine_create(_compare_chr_send, sendco);
837         sendco->done = false;
838         qemu_coroutine_enter(sendco->co);
839         if (sendco->done) {
840             /* report early errors */
841             return sendco->ret;
842         }
843     }
844 
845     /* assume success */
846     return 0;
847 }
848 
849 static int compare_chr_can_read(void *opaque)
850 {
851     return COMPARE_READ_LEN_MAX;
852 }
853 
854 /*
855  * Called from the main thread on the primary for packets
856  * arriving over the socket from the primary.
857  */
858 static void compare_pri_chr_in(void *opaque, const uint8_t *buf, int size)
859 {
860     CompareState *s = COLO_COMPARE(opaque);
861     int ret;
862 
863     ret = net_fill_rstate(&s->pri_rs, buf, size);
864     if (ret == -1) {
865         qemu_chr_fe_set_handlers(&s->chr_pri_in, NULL, NULL, NULL, NULL,
866                                  NULL, NULL, true);
867         error_report("colo-compare primary_in error");
868     }
869 }
870 
871 /*
872  * Called from the main thread on the primary for packets
873  * arriving over the socket from the secondary.
874  */
875 static void compare_sec_chr_in(void *opaque, const uint8_t *buf, int size)
876 {
877     CompareState *s = COLO_COMPARE(opaque);
878     int ret;
879 
880     ret = net_fill_rstate(&s->sec_rs, buf, size);
881     if (ret == -1) {
882         qemu_chr_fe_set_handlers(&s->chr_sec_in, NULL, NULL, NULL, NULL,
883                                  NULL, NULL, true);
884         error_report("colo-compare secondary_in error");
885     }
886 }
887 
888 static void compare_notify_chr(void *opaque, const uint8_t *buf, int size)
889 {
890     CompareState *s = COLO_COMPARE(opaque);
891     int ret;
892 
893     ret = net_fill_rstate(&s->notify_rs, buf, size);
894     if (ret == -1) {
895         qemu_chr_fe_set_handlers(&s->chr_notify_dev, NULL, NULL, NULL, NULL,
896                                  NULL, NULL, true);
897         error_report("colo-compare notify_dev error");
898     }
899 }
900 
901 /*
902  * Check old packet regularly so it can watch for any packets
903  * that the secondary hasn't produced equivalents of.
904  */
905 static void check_old_packet_regular(void *opaque)
906 {
907     CompareState *s = opaque;
908 
909     /* if have old packet we will notify checkpoint */
910     colo_old_packet_check(s);
911     timer_mod(s->packet_check_timer, qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) +
912               s->expired_scan_cycle);
913 }
914 
915 /* Public API, Used for COLO frame to notify compare event */
916 void colo_notify_compares_event(void *opaque, int event, Error **errp)
917 {
918     CompareState *s;
919     qemu_mutex_lock(&colo_compare_mutex);
920 
921     if (!colo_compare_active) {
922         qemu_mutex_unlock(&colo_compare_mutex);
923         return;
924     }
925 
926     qemu_mutex_lock(&event_mtx);
927     QTAILQ_FOREACH(s, &net_compares, next) {
928         s->event = event;
929         qemu_bh_schedule(s->event_bh);
930         event_unhandled_count++;
931     }
932     /* Wait all compare threads to finish handling this event */
933     while (event_unhandled_count > 0) {
934         qemu_cond_wait(&event_complete_cond, &event_mtx);
935     }
936 
937     qemu_mutex_unlock(&event_mtx);
938     qemu_mutex_unlock(&colo_compare_mutex);
939 }
940 
941 static void colo_compare_timer_init(CompareState *s)
942 {
943     AioContext *ctx = iothread_get_aio_context(s->iothread);
944 
945     s->packet_check_timer = aio_timer_new(ctx, QEMU_CLOCK_VIRTUAL,
946                                 SCALE_MS, check_old_packet_regular,
947                                 s);
948     timer_mod(s->packet_check_timer, qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) +
949               s->expired_scan_cycle);
950 }
951 
952 static void colo_compare_timer_del(CompareState *s)
953 {
954     if (s->packet_check_timer) {
955         timer_del(s->packet_check_timer);
956         timer_free(s->packet_check_timer);
957         s->packet_check_timer = NULL;
958     }
959  }
960 
961 static void colo_flush_packets(void *opaque, void *user_data);
962 
963 static void colo_compare_handle_event(void *opaque)
964 {
965     CompareState *s = opaque;
966 
967     switch (s->event) {
968     case COLO_EVENT_CHECKPOINT:
969         g_queue_foreach(&s->conn_list, colo_flush_packets, s);
970         break;
971     case COLO_EVENT_FAILOVER:
972         break;
973     default:
974         break;
975     }
976 
977     qemu_mutex_lock(&event_mtx);
978     assert(event_unhandled_count > 0);
979     event_unhandled_count--;
980     qemu_cond_broadcast(&event_complete_cond);
981     qemu_mutex_unlock(&event_mtx);
982 }
983 
984 static void colo_compare_iothread(CompareState *s)
985 {
986     AioContext *ctx = iothread_get_aio_context(s->iothread);
987     object_ref(OBJECT(s->iothread));
988     s->worker_context = iothread_get_g_main_context(s->iothread);
989 
990     qemu_chr_fe_set_handlers(&s->chr_pri_in, compare_chr_can_read,
991                              compare_pri_chr_in, NULL, NULL,
992                              s, s->worker_context, true);
993     qemu_chr_fe_set_handlers(&s->chr_sec_in, compare_chr_can_read,
994                              compare_sec_chr_in, NULL, NULL,
995                              s, s->worker_context, true);
996     if (s->notify_dev) {
997         qemu_chr_fe_set_handlers(&s->chr_notify_dev, compare_chr_can_read,
998                                  compare_notify_chr, NULL, NULL,
999                                  s, s->worker_context, true);
1000     }
1001 
1002     colo_compare_timer_init(s);
1003     s->event_bh = aio_bh_new(ctx, colo_compare_handle_event, s);
1004 }
1005 
1006 static char *compare_get_pri_indev(Object *obj, Error **errp)
1007 {
1008     CompareState *s = COLO_COMPARE(obj);
1009 
1010     return g_strdup(s->pri_indev);
1011 }
1012 
1013 static void compare_set_pri_indev(Object *obj, const char *value, Error **errp)
1014 {
1015     CompareState *s = COLO_COMPARE(obj);
1016 
1017     g_free(s->pri_indev);
1018     s->pri_indev = g_strdup(value);
1019 }
1020 
1021 static char *compare_get_sec_indev(Object *obj, Error **errp)
1022 {
1023     CompareState *s = COLO_COMPARE(obj);
1024 
1025     return g_strdup(s->sec_indev);
1026 }
1027 
1028 static void compare_set_sec_indev(Object *obj, const char *value, Error **errp)
1029 {
1030     CompareState *s = COLO_COMPARE(obj);
1031 
1032     g_free(s->sec_indev);
1033     s->sec_indev = g_strdup(value);
1034 }
1035 
1036 static char *compare_get_outdev(Object *obj, Error **errp)
1037 {
1038     CompareState *s = COLO_COMPARE(obj);
1039 
1040     return g_strdup(s->outdev);
1041 }
1042 
1043 static void compare_set_outdev(Object *obj, const char *value, Error **errp)
1044 {
1045     CompareState *s = COLO_COMPARE(obj);
1046 
1047     g_free(s->outdev);
1048     s->outdev = g_strdup(value);
1049 }
1050 
1051 static bool compare_get_vnet_hdr(Object *obj, Error **errp)
1052 {
1053     CompareState *s = COLO_COMPARE(obj);
1054 
1055     return s->vnet_hdr;
1056 }
1057 
1058 static void compare_set_vnet_hdr(Object *obj,
1059                                  bool value,
1060                                  Error **errp)
1061 {
1062     CompareState *s = COLO_COMPARE(obj);
1063 
1064     s->vnet_hdr = value;
1065 }
1066 
1067 static char *compare_get_notify_dev(Object *obj, Error **errp)
1068 {
1069     CompareState *s = COLO_COMPARE(obj);
1070 
1071     return g_strdup(s->notify_dev);
1072 }
1073 
1074 static void compare_set_notify_dev(Object *obj, const char *value, Error **errp)
1075 {
1076     CompareState *s = COLO_COMPARE(obj);
1077 
1078     g_free(s->notify_dev);
1079     s->notify_dev = g_strdup(value);
1080 }
1081 
1082 static void compare_get_timeout(Object *obj, Visitor *v,
1083                                 const char *name, void *opaque,
1084                                 Error **errp)
1085 {
1086     CompareState *s = COLO_COMPARE(obj);
1087     uint32_t value = s->compare_timeout;
1088 
1089     visit_type_uint32(v, name, &value, errp);
1090 }
1091 
1092 static void compare_set_timeout(Object *obj, Visitor *v,
1093                                 const char *name, void *opaque,
1094                                 Error **errp)
1095 {
1096     CompareState *s = COLO_COMPARE(obj);
1097     uint32_t value;
1098 
1099     if (!visit_type_uint32(v, name, &value, errp)) {
1100         return;
1101     }
1102     if (!value) {
1103         error_setg(errp, "Property '%s.%s' requires a positive value",
1104                    object_get_typename(obj), name);
1105         return;
1106     }
1107     s->compare_timeout = value;
1108 }
1109 
1110 static void compare_get_expired_scan_cycle(Object *obj, Visitor *v,
1111                                            const char *name, void *opaque,
1112                                            Error **errp)
1113 {
1114     CompareState *s = COLO_COMPARE(obj);
1115     uint32_t value = s->expired_scan_cycle;
1116 
1117     visit_type_uint32(v, name, &value, errp);
1118 }
1119 
1120 static void compare_set_expired_scan_cycle(Object *obj, Visitor *v,
1121                                            const char *name, void *opaque,
1122                                            Error **errp)
1123 {
1124     CompareState *s = COLO_COMPARE(obj);
1125     uint32_t value;
1126 
1127     if (!visit_type_uint32(v, name, &value, errp)) {
1128         return;
1129     }
1130     if (!value) {
1131         error_setg(errp, "Property '%s.%s' requires a positive value",
1132                    object_get_typename(obj), name);
1133         return;
1134     }
1135     s->expired_scan_cycle = value;
1136 }
1137 
1138 static void get_max_queue_size(Object *obj, Visitor *v,
1139                                const char *name, void *opaque,
1140                                Error **errp)
1141 {
1142     uint32_t value = max_queue_size;
1143 
1144     visit_type_uint32(v, name, &value, errp);
1145 }
1146 
1147 static void set_max_queue_size(Object *obj, Visitor *v,
1148                                const char *name, void *opaque,
1149                                Error **errp)
1150 {
1151     Error *local_err = NULL;
1152     uint32_t value;
1153 
1154     visit_type_uint32(v, name, &value, &local_err);
1155     if (local_err) {
1156         goto out;
1157     }
1158     if (!value) {
1159         error_setg(&local_err, "Property '%s.%s' requires a positive value",
1160                    object_get_typename(obj), name);
1161         goto out;
1162     }
1163     max_queue_size = value;
1164 
1165 out:
1166     error_propagate(errp, local_err);
1167 }
1168 
1169 static void compare_pri_rs_finalize(SocketReadState *pri_rs)
1170 {
1171     CompareState *s = container_of(pri_rs, CompareState, pri_rs);
1172     Connection *conn = NULL;
1173 
1174     if (packet_enqueue(s, PRIMARY_IN, &conn)) {
1175         trace_colo_compare_main("primary: unsupported packet in");
1176         compare_chr_send(s,
1177                          pri_rs->buf,
1178                          pri_rs->packet_len,
1179                          pri_rs->vnet_hdr_len,
1180                          false,
1181                          false);
1182     } else {
1183         /* compare packet in the specified connection */
1184         colo_compare_connection(conn, s);
1185     }
1186 }
1187 
1188 static void compare_sec_rs_finalize(SocketReadState *sec_rs)
1189 {
1190     CompareState *s = container_of(sec_rs, CompareState, sec_rs);
1191     Connection *conn = NULL;
1192 
1193     if (packet_enqueue(s, SECONDARY_IN, &conn)) {
1194         trace_colo_compare_main("secondary: unsupported packet in");
1195     } else {
1196         /* compare packet in the specified connection */
1197         colo_compare_connection(conn, s);
1198     }
1199 }
1200 
1201 static void compare_notify_rs_finalize(SocketReadState *notify_rs)
1202 {
1203     CompareState *s = container_of(notify_rs, CompareState, notify_rs);
1204 
1205     const char msg[] = "COLO_COMPARE_GET_XEN_INIT";
1206     int ret;
1207 
1208     if (packet_matches_str("COLO_USERSPACE_PROXY_INIT",
1209                            notify_rs->buf,
1210                            notify_rs->packet_len)) {
1211         ret = compare_chr_send(s, (uint8_t *)msg, strlen(msg), 0, true, false);
1212         if (ret < 0) {
1213             error_report("Notify Xen COLO-frame INIT failed");
1214         }
1215     } else if (packet_matches_str("COLO_CHECKPOINT",
1216                                   notify_rs->buf,
1217                                   notify_rs->packet_len)) {
1218         /* colo-compare do checkpoint, flush pri packet and remove sec packet */
1219         g_queue_foreach(&s->conn_list, colo_flush_packets, s);
1220     } else {
1221         error_report("COLO compare got unsupported instruction");
1222     }
1223 }
1224 
1225 /*
1226  * Return 0 is success.
1227  * Return 1 is failed.
1228  */
1229 static int find_and_check_chardev(Chardev **chr,
1230                                   char *chr_name,
1231                                   Error **errp)
1232 {
1233     *chr = qemu_chr_find(chr_name);
1234     if (*chr == NULL) {
1235         error_setg(errp, "Device '%s' not found",
1236                    chr_name);
1237         return 1;
1238     }
1239 
1240     if (!qemu_chr_has_feature(*chr, QEMU_CHAR_FEATURE_RECONNECTABLE)) {
1241         error_setg(errp, "chardev \"%s\" is not reconnectable",
1242                    chr_name);
1243         return 1;
1244     }
1245 
1246     if (!qemu_chr_has_feature(*chr, QEMU_CHAR_FEATURE_GCONTEXT)) {
1247         error_setg(errp, "chardev \"%s\" cannot switch context",
1248                    chr_name);
1249         return 1;
1250     }
1251 
1252     return 0;
1253 }
1254 
1255 /*
1256  * Called from the main thread on the primary
1257  * to setup colo-compare.
1258  */
1259 static void colo_compare_complete(UserCreatable *uc, Error **errp)
1260 {
1261     CompareState *s = COLO_COMPARE(uc);
1262     Chardev *chr;
1263 
1264     if (!s->pri_indev || !s->sec_indev || !s->outdev || !s->iothread) {
1265         error_setg(errp, "colo compare needs 'primary_in' ,"
1266                    "'secondary_in','outdev','iothread' property set");
1267         return;
1268     } else if (!strcmp(s->pri_indev, s->outdev) ||
1269                !strcmp(s->sec_indev, s->outdev) ||
1270                !strcmp(s->pri_indev, s->sec_indev)) {
1271         error_setg(errp, "'indev' and 'outdev' could not be same "
1272                    "for compare module");
1273         return;
1274     }
1275 
1276     if (!s->compare_timeout) {
1277         /* Set default value to 3000 MS */
1278         s->compare_timeout = DEFAULT_TIME_OUT_MS;
1279     }
1280 
1281     if (!s->expired_scan_cycle) {
1282         /* Set default value to 3000 MS */
1283         s->expired_scan_cycle = REGULAR_PACKET_CHECK_MS;
1284     }
1285 
1286     if (!max_queue_size) {
1287         /* Set default queue size to 1024 */
1288         max_queue_size = MAX_QUEUE_SIZE;
1289     }
1290 
1291     if (find_and_check_chardev(&chr, s->pri_indev, errp) ||
1292         !qemu_chr_fe_init(&s->chr_pri_in, chr, errp)) {
1293         return;
1294     }
1295 
1296     if (find_and_check_chardev(&chr, s->sec_indev, errp) ||
1297         !qemu_chr_fe_init(&s->chr_sec_in, chr, errp)) {
1298         return;
1299     }
1300 
1301     if (find_and_check_chardev(&chr, s->outdev, errp) ||
1302         !qemu_chr_fe_init(&s->chr_out, chr, errp)) {
1303         return;
1304     }
1305 
1306     net_socket_rs_init(&s->pri_rs, compare_pri_rs_finalize, s->vnet_hdr);
1307     net_socket_rs_init(&s->sec_rs, compare_sec_rs_finalize, s->vnet_hdr);
1308 
1309     /* Try to enable remote notify chardev, currently just for Xen COLO */
1310     if (s->notify_dev) {
1311         if (find_and_check_chardev(&chr, s->notify_dev, errp) ||
1312             !qemu_chr_fe_init(&s->chr_notify_dev, chr, errp)) {
1313             return;
1314         }
1315 
1316         net_socket_rs_init(&s->notify_rs, compare_notify_rs_finalize,
1317                            s->vnet_hdr);
1318     }
1319 
1320     s->out_sendco.s = s;
1321     s->out_sendco.chr = &s->chr_out;
1322     s->out_sendco.notify_remote_frame = false;
1323     s->out_sendco.done = true;
1324     g_queue_init(&s->out_sendco.send_list);
1325 
1326     if (s->notify_dev) {
1327         s->notify_sendco.s = s;
1328         s->notify_sendco.chr = &s->chr_notify_dev;
1329         s->notify_sendco.notify_remote_frame = true;
1330         s->notify_sendco.done = true;
1331         g_queue_init(&s->notify_sendco.send_list);
1332     }
1333 
1334     g_queue_init(&s->conn_list);
1335 
1336     s->connection_track_table = g_hash_table_new_full(connection_key_hash,
1337                                                       connection_key_equal,
1338                                                       g_free,
1339                                                       connection_destroy);
1340 
1341     colo_compare_iothread(s);
1342 
1343     qemu_mutex_lock(&colo_compare_mutex);
1344     if (!colo_compare_active) {
1345         qemu_mutex_init(&event_mtx);
1346         qemu_cond_init(&event_complete_cond);
1347         colo_compare_active = true;
1348     }
1349     QTAILQ_INSERT_TAIL(&net_compares, s, next);
1350     qemu_mutex_unlock(&colo_compare_mutex);
1351 
1352     return;
1353 }
1354 
1355 static void colo_flush_packets(void *opaque, void *user_data)
1356 {
1357     CompareState *s = user_data;
1358     Connection *conn = opaque;
1359     Packet *pkt = NULL;
1360 
1361     while (!g_queue_is_empty(&conn->primary_list)) {
1362         pkt = g_queue_pop_head(&conn->primary_list);
1363         compare_chr_send(s,
1364                          pkt->data,
1365                          pkt->size,
1366                          pkt->vnet_hdr_len,
1367                          false,
1368                          true);
1369         packet_destroy_partial(pkt, NULL);
1370     }
1371     while (!g_queue_is_empty(&conn->secondary_list)) {
1372         pkt = g_queue_pop_head(&conn->secondary_list);
1373         packet_destroy(pkt, NULL);
1374     }
1375 }
1376 
1377 static void colo_compare_class_init(ObjectClass *oc, void *data)
1378 {
1379     UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);
1380 
1381     ucc->complete = colo_compare_complete;
1382 }
1383 
1384 static void colo_compare_init(Object *obj)
1385 {
1386     CompareState *s = COLO_COMPARE(obj);
1387 
1388     object_property_add_str(obj, "primary_in",
1389                             compare_get_pri_indev, compare_set_pri_indev);
1390     object_property_add_str(obj, "secondary_in",
1391                             compare_get_sec_indev, compare_set_sec_indev);
1392     object_property_add_str(obj, "outdev",
1393                             compare_get_outdev, compare_set_outdev);
1394     object_property_add_link(obj, "iothread", TYPE_IOTHREAD,
1395                             (Object **)&s->iothread,
1396                             object_property_allow_set_link,
1397                             OBJ_PROP_LINK_STRONG);
1398     /* This parameter just for Xen COLO */
1399     object_property_add_str(obj, "notify_dev",
1400                             compare_get_notify_dev, compare_set_notify_dev);
1401 
1402     object_property_add(obj, "compare_timeout", "uint32",
1403                         compare_get_timeout,
1404                         compare_set_timeout, NULL, NULL);
1405 
1406     object_property_add(obj, "expired_scan_cycle", "uint32",
1407                         compare_get_expired_scan_cycle,
1408                         compare_set_expired_scan_cycle, NULL, NULL);
1409 
1410     object_property_add(obj, "max_queue_size", "uint32",
1411                         get_max_queue_size,
1412                         set_max_queue_size, NULL, NULL);
1413 
1414     s->vnet_hdr = false;
1415     object_property_add_bool(obj, "vnet_hdr_support", compare_get_vnet_hdr,
1416                              compare_set_vnet_hdr);
1417 }
1418 
1419 static void colo_compare_finalize(Object *obj)
1420 {
1421     CompareState *s = COLO_COMPARE(obj);
1422     CompareState *tmp = NULL;
1423 
1424     qemu_mutex_lock(&colo_compare_mutex);
1425     QTAILQ_FOREACH(tmp, &net_compares, next) {
1426         if (tmp == s) {
1427             QTAILQ_REMOVE(&net_compares, s, next);
1428             break;
1429         }
1430     }
1431     if (QTAILQ_EMPTY(&net_compares)) {
1432         colo_compare_active = false;
1433         qemu_mutex_destroy(&event_mtx);
1434         qemu_cond_destroy(&event_complete_cond);
1435     }
1436     qemu_mutex_unlock(&colo_compare_mutex);
1437 
1438     qemu_chr_fe_deinit(&s->chr_pri_in, false);
1439     qemu_chr_fe_deinit(&s->chr_sec_in, false);
1440     qemu_chr_fe_deinit(&s->chr_out, false);
1441     if (s->notify_dev) {
1442         qemu_chr_fe_deinit(&s->chr_notify_dev, false);
1443     }
1444 
1445     if (s->iothread) {
1446         colo_compare_timer_del(s);
1447     }
1448 
1449     qemu_bh_delete(s->event_bh);
1450 
1451     AioContext *ctx = iothread_get_aio_context(s->iothread);
1452     aio_context_acquire(ctx);
1453     AIO_WAIT_WHILE(ctx, !s->out_sendco.done);
1454     if (s->notify_dev) {
1455         AIO_WAIT_WHILE(ctx, !s->notify_sendco.done);
1456     }
1457     aio_context_release(ctx);
1458 
1459     /* Release all unhandled packets after compare thead exited */
1460     g_queue_foreach(&s->conn_list, colo_flush_packets, s);
1461     AIO_WAIT_WHILE(NULL, !s->out_sendco.done);
1462 
1463     g_queue_clear(&s->conn_list);
1464     g_queue_clear(&s->out_sendco.send_list);
1465     if (s->notify_dev) {
1466         g_queue_clear(&s->notify_sendco.send_list);
1467     }
1468 
1469     if (s->connection_track_table) {
1470         g_hash_table_destroy(s->connection_track_table);
1471     }
1472 
1473     if (s->iothread) {
1474         object_unref(OBJECT(s->iothread));
1475     }
1476 
1477     g_free(s->pri_indev);
1478     g_free(s->sec_indev);
1479     g_free(s->outdev);
1480     g_free(s->notify_dev);
1481 }
1482 
1483 static void __attribute__((__constructor__)) colo_compare_init_globals(void)
1484 {
1485     colo_compare_active = false;
1486     qemu_mutex_init(&colo_compare_mutex);
1487 }
1488 
1489 static const TypeInfo colo_compare_info = {
1490     .name = TYPE_COLO_COMPARE,
1491     .parent = TYPE_OBJECT,
1492     .instance_size = sizeof(CompareState),
1493     .instance_init = colo_compare_init,
1494     .instance_finalize = colo_compare_finalize,
1495     .class_size = sizeof(CompareClass),
1496     .class_init = colo_compare_class_init,
1497     .interfaces = (InterfaceInfo[]) {
1498         { TYPE_USER_CREATABLE },
1499         { }
1500     }
1501 };
1502 
1503 static void register_types(void)
1504 {
1505     type_register_static(&colo_compare_info);
1506 }
1507 
1508 type_init(register_types);
1509