2  * QEMU live migration
20 #include "migration/blocker.h"
30 #include "migration/global_state.h"
31 #include "migration/misc.h"
32 #include "migration.h"
33 #include "migration-stats.h"
37 #include "migration/vmstate.h"
41 #include "qapi/qapi-visit-migration.h"
43 #include "qapi/qapi-commands-migration.h"
44 #include "qapi/qapi-events-migration.h"
54 #include "migration/colo.h"
97    dynamic creation of migration */
189         error_setg(errp, "Migration requires seekable transport (e.g. file)");  in migration_channels_and_transport_compatible()
195         error_setg(errp, "Migration requires multi-channel URIs (e.g. tcp)");  in migration_channels_and_transport_compatible()
202                    "Migration requires a transport that allows for extra fds (e.g. file)");  in migration_channels_and_transport_compatible()
328      * COLO thread before migration shutdown.  in migration_shutdown()
332      * Cancel the current migration - that will (eventually)  in migration_shutdown()
333      * stop the migration using this structure  in migration_shutdown()
339      * Cancel outgoing migration of dirty bitmaps. It should  in migration_shutdown()
345      * Cancel incoming migration of dirty bitmaps. Dirty bitmaps  in migration_shutdown()
433  * of the migration.
547     error_report("ENABLE_COLO command come in migration stream, but the "  in migration_incoming_enable_colo()
553         error_report("ENABLE_COLO command come in migration stream, but x-colo "  in migration_incoming_enable_colo()
619         error_setg(errp, "unknown migration protocol: %s", uri);  in migrate_uri_parse()
636          * Incoming postcopy migration will stay in PAUSED state even if  in migration_incoming_state_setup()
643         error_setg(errp, "Illegal migration incoming state: %s",  in migration_incoming_state_setup()
685     /* transport mechanism not suitable for migration? */  in qemu_start_incoming_migration()
720         error_setg(errp, "unknown migration protocol: %s", uri);  in qemu_start_incoming_migration()
813              * Where a migration had postcopy enabled (and thus went to advise)  in process_incoming_migration_co()
830         error_setg(&local_err, "load of migration failed: %s", strerror(-ret));  in process_incoming_migration_co()
860  * migration_incoming_setup: Setup incoming migration
861  * @f: file for main migration channel
879 /* Returns true if recovered from a paused migration, otherwise false */
885         /* Resumed from a paused postcopy migration */  in postcopy_try_recover()
922  * Returns true when we want to start a new incoming migration process,
938      * For all the rest types of migration, we should only reach here when  in migration_should_start_incoming()
964          * postcopy live migration. Also tls live migration already does  in migration_ioc_process_incoming()
1016  * we need for migration.
1236      * There are two types of reasons a migration might be blocked;  in fill_source_migration_info()
1238      * b) Explicit migration blockers  in fill_source_migration_info()
1252         /* no migration has happened ever */  in fill_source_migration_info()
1253         /* do not overwrite destination migration status */  in fill_source_migration_info()
1356                          " the start of migration");  in qmp_migrate_start_postcopy()
1361         error_setg(errp, "Postcopy must be started after migration has been"  in qmp_migrate_start_postcopy()
1366      * we don't error if migration has finished since that would be racy  in qmp_migrate_start_postcopy()
1372 /* shared migration helpers */
1488         /* Never fail a postcopy migration; switch back to PAUSED instead */  in migrate_fd_error()
1496         error_report("%s: Illegal migration status (%s) detected",  in migrate_fd_error()
1523         /* If the migration is paused, kick it out of the pause */  in migrate_fd_cancel()
1531      * If we're unlucky the migration code might be stuck somewhere in a  in migrate_fd_cancel()
1677      * Reinitialise all migration state, except  in migrate_init()
1705      * set mig_stats memory to zero for a new migration  in migrate_init()
1720                                 "disallowing migration blocker "  in is_busy()
1721                                 "(migration/snapshot in progress) for: ");  in is_busy()
1734                                 "disallowing migration blocker "  in is_only_migratable()
1827         error_setg(errp, "The incoming migration has already been started");  in qmp_migrate_incoming()
1874      * Note that this call will never start a real migration; it will  in qmp_migrate_recover()
1875      * only re-setup the migration stream and poke existing migration  in qmp_migrate_recover()
1891         /* Tell the core migration that we're pausing */  in qmp_migrate_pause()
1892         error_setg(&error, "Postcopy migration is paused by the user");  in qmp_migrate_pause()
1902             error_setg(errp, "Failed to pause source migration");  in qmp_migrate_pause()
1906          * Kick the migration thread out of any waiting windows (on behalf  in qmp_migrate_pause()
1917             error_setg(errp, "Failed to pause destination migration");  in qmp_migrate_pause()
1948                        "paused migration");  in migrate_prepare()
1959          * the client from resuming such a postcopy migration.  in migrate_prepare()
1978         error_setg(errp, "There's a migration process in progress");  in migrate_prepare()
1983         error_setg(errp, "Guest is waiting for an incoming migration");  in migrate_prepare()
1989                    "previous migration");  in migrate_prepare()
2074     /* transport mechanism not suitable for migration? */  in qmp_migrate()
2110                    "a valid migration protocol");  in qmp_migrate()
2134         error_setg(errp,  "Migration not in expected state: %s",  in qmp_migrate_continue()
2143     /* If migration has failure already, ignore the wait */  in migration_rp_wait()
2421          * period the main migration thread can be waiting on rp_sem for  in source_return_path_thread()
2424          * When this happens, explicitly kick the migration thread out of  in source_return_path_thread()
2577      * it starts processing it.  Unfortunately the ad-hoc migration format  in postcopy_start()
2585     qio_channel_set_name(QIO_CHANNEL(bioc), "migration-postcopy-buffer");  in postcopy_start()
2610         error_setg(errp, "postcopy_start: Migration stream errored (pre package)");  in postcopy_start()
2647         error_setg_errno(errp, -ret, "postcopy_start: Migration stream error");  in postcopy_start()
2700      * If the migration is cancelled when it is in the completion phase,  in migration_maybe_pause()
2701      * the migration state is set to MIGRATION_STATUS_CANCELLING.  in migration_maybe_pause()
2741      * to remember to reactivate them if migration fails or is cancelled.  in migration_completion_precopy()
2800  * @s: Current migration state
2844         error_setg_errno(&local_err, -ret, "Error in migration completion");  in migration_completion()
2856  * @s: Current migration state
2864          * By this moment we have RAM content saved into the migration stream.  in bg_migration_completion()
2921      * ready for the migration resume.  in postcopy_do_resume()
2959  * postcopy migration.  Returns MIG_THR_ERR_RECOVERED if recovered, or
2979          * modified by the migration thread.  That also guarantees that the  in postcopy_pause()
2999                      "Migration paused.");  in postcopy_pause()
3053         /* End the migration, but don't set the state to failed */  in migration_detect_error()
3090         /* Time to stop the migration, now. */  in migration_detect_error()
3205 /* Migration thread iteration status */
3408              * migration has been canceled  in qemu_savevm_wait_unplug()
3417                 warn_report("migration: partially unplugged device on "  in qemu_savevm_wait_unplug()
3429  * Master migration thread on the source VM.
3430  * It drives the migration and pumps the data down the outgoing channel.
3479         /* Notify migration destination that we enable COLO */  in migration_thread()
3497      * devices to unplug. This to preserve migration state transitions.  in migration_thread()
3523          * should stop the migration now.  in migration_thread()
3527             /* Stop migration */  in migration_thread()
3559  * Background snapshot thread, based on live migration code.
3560  * This is an alternative implementation of live migration mechanism
3564  * in v5.7 kernel. Compared to existing dirty page logging migration much
3589      * We want to save vmstate for the moment when migration has been  in bg_migration_thread()
3593      * then write RAM part of the vmstate to the migration stream  in bg_migration_thread()
3595      * the vmstate from the buffer to the migration stream.  in bg_migration_thread()
3622      * devices to unplug. This to preserve migration state transitions.  in bg_migration_thread()
3680          * should stop the migration now.  in bg_migration_thread()
3684             /* Stop migration */  in bg_migration_thread()
3719      * Meanwhile if migration completes successfully, there won't have an error  in migrate_fd_connect()
3743         /* This is a resumed migration */  in migrate_fd_connect()
3746         /* This is a fresh new migration */  in migrate_fd_connect()
3749         /* Notify before starting migration thread */  in migrate_fd_connect()
3780         /* Wakeup the main migration thread to do the recovery */  in migrate_fd_connect()
3796      * Take a refcount to make sure the migration object won't get freed by  in migrate_fd_connect()