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     /* Note for save_live_pending:
  50      * must_precopy:
  51      * - must be migrated in precopy or in stopped state
  52      * - i.e. must be migrated before target start
  53      *
  54      * can_postcopy:
  55      * - can migrate in postcopy or in stopped state
  56      * - i.e. can migrate after target start
  57      * - some can also be migrated during precopy (RAM)
  58      * - some must be migrated after source stops (block-dirty-bitmap)
  59      *
  60      * Sum of can_postcopy and must_postcopy is the whole amount of
  61      * pending data.
  62      */
  63     /* This estimates the remaining data to transfer */
  64     void (*state_pending_estimate)(void *opaque, uint64_t *must_precopy,
  65                                    uint64_t *can_postcopy);
  66     /* This calculate the exact remaining data to transfer */
  67     void (*state_pending_exact)(void *opaque, uint64_t *must_precopy,
  68                                 uint64_t *can_postcopy);
  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