xref: /openbmc/qemu/include/migration/register.h (revision 93e0932b)
1 /*
2  * QEMU migration vmstate registration
3  *
4  * Copyright IBM, Corp. 2008
5  *
6  * Authors:
7  *  Anthony Liguori   <aliguori@us.ibm.com>
8  *
9  * This work is licensed under the terms of the GNU GPL, version 2.  See
10  * the COPYING file in the top-level directory.
11  *
12  */
13 
14 #ifndef MIGRATION_REGISTER_H
15 #define MIGRATION_REGISTER_H
16 
17 #include "hw/vmstate-if.h"
18 
19 typedef struct SaveVMHandlers {
20     /* This runs inside the iothread lock.  */
21     SaveStateHandler *save_state;
22 
23     void (*save_cleanup)(void *opaque);
24     int (*save_live_complete_postcopy)(QEMUFile *f, void *opaque);
25     int (*save_live_complete_precopy)(QEMUFile *f, void *opaque);
26 
27     /* This runs both outside and inside the iothread lock.  */
28     bool (*is_active)(void *opaque);
29     bool (*has_postcopy)(void *opaque);
30 
31     /* is_active_iterate
32      * If it is not NULL then qemu_savevm_state_iterate will skip iteration if
33      * it returns false. For example, it is needed for only-postcopy-states,
34      * which needs to be handled by qemu_savevm_state_setup and
35      * qemu_savevm_state_pending, but do not need iterations until not in
36      * postcopy stage.
37      */
38     bool (*is_active_iterate)(void *opaque);
39 
40     /* This runs outside the iothread lock in the migration case, and
41      * within the lock in the savevm case.  The callback had better only
42      * use data that is local to the migration thread or protected
43      * by other locks.
44      */
45     int (*save_live_iterate)(QEMUFile *f, void *opaque);
46 
47     /* This runs outside the iothread lock!  */
48     int (*save_setup)(QEMUFile *f, void *opaque);
49     /* Note for save_live_pending:
50      * - res_precopy_only is for data which must be migrated in precopy phase
51      *     or in stopped state, in other words - before target vm start
52      * - res_compatible is for data which may be migrated in any phase
53      * - res_postcopy_only is for data which must be migrated in postcopy phase
54      *     or in stopped state, in other words - after source vm stop
55      *
56      * Sum of res_postcopy_only, res_compatible and res_postcopy_only is the
57      * whole amount of pending data.
58      */
59     /* This estimates the remaining data to transfer */
60     void (*state_pending_estimate)(void *opaque,
61                                    uint64_t *res_precopy_only,
62                                    uint64_t *res_compatible,
63                                    uint64_t *res_postcopy_only);
64     /* This calculate the exact remaining data to transfer */
65     void (*state_pending_exact)(void *opaque,
66                                 uint64_t *res_precopy_only,
67                                 uint64_t *res_compatible,
68                                 uint64_t *res_postcopy_only);
69     LoadStateHandler *load_state;
70     int (*load_setup)(QEMUFile *f, void *opaque);
71     int (*load_cleanup)(void *opaque);
72     /* Called when postcopy migration wants to resume from failure */
73     int (*resume_prepare)(MigrationState *s, void *opaque);
74 } SaveVMHandlers;
75 
76 int register_savevm_live(const char *idstr,
77                          uint32_t instance_id,
78                          int version_id,
79                          const SaveVMHandlers *ops,
80                          void *opaque);
81 
82 void unregister_savevm(VMStateIf *obj, const char *idstr, void *opaque);
83 
84 #endif
85