include/migration/register.h

   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 typedef struct SaveVMHandlers {
  18     /* This runs inside the iothread lock.  */
  19     SaveStateHandler *save_state;
  20
  21     void (*save_cleanup)(void *opaque);
  22     int (*save_live_complete_postcopy)(QEMUFile *f, void *opaque);
  23     int (*save_live_complete_precopy)(QEMUFile *f, void *opaque);
  24
  25     /* This runs both outside and inside the iothread lock.  */
  26     bool (*is_active)(void *opaque);
  27     bool (*has_postcopy)(void *opaque);
  28
  29     /* is_active_iterate
  30      * If it is not NULL then qemu_savevm_state_iterate will skip iteration if
  31      * it returns false. For example, it is needed for only-postcopy-states,
  32      * which needs to be handled by qemu_savevm_state_setup and
  33      * qemu_savevm_state_pending, but do not need iterations until not in
  34      * postcopy stage.
  35      */
  36     bool (*is_active_iterate)(void *opaque);
  37
  38     /* This runs outside the iothread lock in the migration case, and
  39      * within the lock in the savevm case.  The callback had better only
  40      * use data that is local to the migration thread or protected
  41      * by other locks.
  42      */
  43     int (*save_live_iterate)(QEMUFile *f, void *opaque);
  44
  45     /* This runs outside the iothread lock!  */
  46     int (*save_setup)(QEMUFile *f, void *opaque);
  47     void (*save_live_pending)(QEMUFile *f, void *opaque,
  48                               uint64_t threshold_size,
  49                               uint64_t *res_precopy_only,
  50                               uint64_t *res_compatible,
  51                               uint64_t *res_postcopy_only);
  52     /* Note for save_live_pending:
  53      * - res_precopy_only is for data which must be migrated in precopy phase
  54      *     or in stopped state, in other words - before target vm start
  55      * - res_compatible is for data which may be migrated in any phase
  56      * - res_postcopy_only is for data which must be migrated in postcopy phase
  57      *     or in stopped state, in other words - after source vm stop
  58      *
  59      * Sum of res_postcopy_only, res_compatible and res_postcopy_only is the
  60      * whole amount of pending data.
  61      */
  62
  63
  64     LoadStateHandler *load_state;
  65     int (*load_setup)(QEMUFile *f, void *opaque);
  66     int (*load_cleanup)(void *opaque);
  67     /* Called when postcopy migration wants to resume from failure */
  68     int (*resume_prepare)(MigrationState *s, void *opaque);
  69 } SaveVMHandlers;
  70
  71 int register_savevm_live(DeviceState *dev,
  72                          const char *idstr,
  73                          int instance_id,
  74                          int version_id,
  75                          const SaveVMHandlers *ops,
  76                          void *opaque);
  77
  78 void unregister_savevm(DeviceState *dev, const char *idstr, void *opaque);
  79
  80 #endif