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 #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     void (*save_live_pending)(QEMUFile *f, void *opaque,
  50                               uint64_t threshold_size,
  51                               uint64_t *res_precopy_only,
  52                               uint64_t *res_compatible,
  53                               uint64_t *res_postcopy_only);
  54     /* Note for save_live_pending:
  55      * - res_precopy_only is for data which must be migrated in precopy phase
  56      *     or in stopped state, in other words - before target vm start
  57      * - res_compatible is for data which may be migrated in any phase
  58      * - res_postcopy_only is for data which must be migrated in postcopy phase
  59      *     or in stopped state, in other words - after source vm stop
  60      *
  61      * Sum of res_postcopy_only, res_compatible and res_postcopy_only is the
  62      * whole amount of pending data.
  63      */
  64
  65
  66     LoadStateHandler *load_state;
  67     int (*load_setup)(QEMUFile *f, void *opaque);
  68     int (*load_cleanup)(void *opaque);
  69     /* Called when postcopy migration wants to resume from failure */
  70     int (*resume_prepare)(MigrationState *s, void *opaque);
  71 } SaveVMHandlers;
  72
  73 int register_savevm_live(const char *idstr,
  74                          uint32_t instance_id,
  75                          int version_id,
  76                          const SaveVMHandlers *ops,
  77                          void *opaque);
  78
  79 void unregister_savevm(VMStateIf *obj, const char *idstr, void *opaque);
  80
  81 #endif