diff options
Diffstat (limited to 'migration/migration.c')
| -rw-r--r-- | migration/migration.c | 700 |
1 files changed, 700 insertions, 0 deletions
diff --git a/migration/migration.c b/migration/migration.c new file mode 100644 index 0000000000..c49a05a165 --- /dev/null +++ b/migration/migration.c @@ -0,0 +1,700 @@ +/* + * QEMU live migration + * + * Copyright IBM, Corp. 2008 + * + * Authors: + * Anthony Liguori <aliguori@us.ibm.com> + * + * This work is licensed under the terms of the GNU GPL, version 2. See + * the COPYING file in the top-level directory. + * + * Contributions after 2012-01-13 are licensed under the terms of the + * GNU GPL, version 2 or (at your option) any later version. + */ + +#include "qemu-common.h" +#include "qemu/main-loop.h" +#include "migration/migration.h" +#include "monitor/monitor.h" +#include "migration/qemu-file.h" +#include "sysemu/sysemu.h" +#include "block/block.h" +#include "qemu/sockets.h" +#include "migration/block.h" +#include "qemu/thread.h" +#include "qmp-commands.h" +#include "trace.h" + +enum { + MIG_STATE_ERROR = -1, + MIG_STATE_NONE, + MIG_STATE_SETUP, + MIG_STATE_CANCELLING, + MIG_STATE_CANCELLED, + MIG_STATE_ACTIVE, + MIG_STATE_COMPLETED, +}; + +#define MAX_THROTTLE (32 << 20) /* Migration speed throttling */ + +/* Amount of time to allocate to each "chunk" of bandwidth-throttled + * data. */ +#define BUFFER_DELAY 100 +#define XFER_LIMIT_RATIO (1000 / BUFFER_DELAY) + +/* Migration XBZRLE default cache size */ +#define DEFAULT_MIGRATE_CACHE_SIZE (64 * 1024 * 1024) + +static NotifierList migration_state_notifiers = + NOTIFIER_LIST_INITIALIZER(migration_state_notifiers); + +/* When we add fault tolerance, we could have several + migrations at once. For now we don't need to add + dynamic creation of migration */ + +MigrationState *migrate_get_current(void) +{ + static MigrationState current_migration = { + .state = MIG_STATE_NONE, + .bandwidth_limit = MAX_THROTTLE, + .xbzrle_cache_size = DEFAULT_MIGRATE_CACHE_SIZE, + .mbps = -1, + }; + + return ¤t_migration; +} + +void qemu_start_incoming_migration(const char *uri, Error **errp) +{ + const char *p; + + if (strstart(uri, "tcp:", &p)) + tcp_start_incoming_migration(p, errp); +#ifdef CONFIG_RDMA + else if (strstart(uri, "rdma:", &p)) + rdma_start_incoming_migration(p, errp); +#endif +#if !defined(WIN32) + else if (strstart(uri, "exec:", &p)) + exec_start_incoming_migration(p, errp); + else if (strstart(uri, "unix:", &p)) + unix_start_incoming_migration(p, errp); + else if (strstart(uri, "fd:", &p)) + fd_start_incoming_migration(p, errp); +#endif + else { + error_setg(errp, "unknown migration protocol: %s", uri); + } +} + +static void process_incoming_migration_co(void *opaque) +{ + QEMUFile *f = opaque; + Error *local_err = NULL; + int ret; + + ret = qemu_loadvm_state(f); + qemu_fclose(f); + free_xbzrle_decoded_buf(); + if (ret < 0) { + error_report("load of migration failed: %s", strerror(-ret)); + exit(EXIT_FAILURE); + } + qemu_announce_self(); + + /* Make sure all file formats flush their mutable metadata */ + bdrv_invalidate_cache_all(&local_err); + if (local_err) { + qerror_report_err(local_err); + error_free(local_err); + exit(EXIT_FAILURE); + } + + if (autostart) { + vm_start(); + } else { + runstate_set(RUN_STATE_PAUSED); + } +} + +void process_incoming_migration(QEMUFile *f) +{ + Coroutine *co = qemu_coroutine_create(process_incoming_migration_co); + int fd = qemu_get_fd(f); + + assert(fd != -1); + qemu_set_nonblock(fd); + qemu_coroutine_enter(co, f); +} + +/* amount of nanoseconds we are willing to wait for migration to be down. + * the choice of nanoseconds is because it is the maximum resolution that + * get_clock() can achieve. It is an internal measure. All user-visible + * units must be in seconds */ +static uint64_t max_downtime = 300000000; + +uint64_t migrate_max_downtime(void) +{ + return max_downtime; +} + +MigrationCapabilityStatusList *qmp_query_migrate_capabilities(Error **errp) +{ + MigrationCapabilityStatusList *head = NULL; + MigrationCapabilityStatusList *caps; + MigrationState *s = migrate_get_current(); + int i; + + caps = NULL; /* silence compiler warning */ + for (i = 0; i < MIGRATION_CAPABILITY_MAX; i++) { + if (head == NULL) { + head = g_malloc0(sizeof(*caps)); + caps = head; + } else { + caps->next = g_malloc0(sizeof(*caps)); + caps = caps->next; + } + caps->value = + g_malloc(sizeof(*caps->value)); + caps->value->capability = i; + caps->value->state = s->enabled_capabilities[i]; + } + + return head; +} + +static void get_xbzrle_cache_stats(MigrationInfo *info) +{ + if (migrate_use_xbzrle()) { + info->has_xbzrle_cache = true; + info->xbzrle_cache = g_malloc0(sizeof(*info->xbzrle_cache)); + info->xbzrle_cache->cache_size = migrate_xbzrle_cache_size(); + info->xbzrle_cache->bytes = xbzrle_mig_bytes_transferred(); + info->xbzrle_cache->pages = xbzrle_mig_pages_transferred(); + info->xbzrle_cache->cache_miss = xbzrle_mig_pages_cache_miss(); + info->xbzrle_cache->cache_miss_rate = xbzrle_mig_cache_miss_rate(); + info->xbzrle_cache->overflow = xbzrle_mig_pages_overflow(); + } +} + +MigrationInfo *qmp_query_migrate(Error **errp) +{ + MigrationInfo *info = g_malloc0(sizeof(*info)); + MigrationState *s = migrate_get_current(); + + switch (s->state) { + case MIG_STATE_NONE: + /* no migration has happened ever */ + break; + case MIG_STATE_SETUP: + info->has_status = true; + info->status = g_strdup("setup"); + info->has_total_time = false; + break; + case MIG_STATE_ACTIVE: + case MIG_STATE_CANCELLING: + info->has_status = true; + info->status = g_strdup("active"); + info->has_total_time = true; + info->total_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME) + - s->total_time; + info->has_expected_downtime = true; + info->expected_downtime = s->expected_downtime; + info->has_setup_time = true; + info->setup_time = s->setup_time; + + info->has_ram = true; + info->ram = g_malloc0(sizeof(*info->ram)); + info->ram->transferred = ram_bytes_transferred(); + info->ram->remaining = ram_bytes_remaining(); + info->ram->total = ram_bytes_total(); + info->ram->duplicate = dup_mig_pages_transferred(); + info->ram->skipped = skipped_mig_pages_transferred(); + info->ram->normal = norm_mig_pages_transferred(); + info->ram->normal_bytes = norm_mig_bytes_transferred(); + info->ram->dirty_pages_rate = s->dirty_pages_rate; + info->ram->mbps = s->mbps; + info->ram->dirty_sync_count = s->dirty_sync_count; + + if (blk_mig_active()) { + info->has_disk = true; + info->disk = g_malloc0(sizeof(*info->disk)); + info->disk->transferred = blk_mig_bytes_transferred(); + info->disk->remaining = blk_mig_bytes_remaining(); + info->disk->total = blk_mig_bytes_total(); + } + + get_xbzrle_cache_stats(info); + break; + case MIG_STATE_COMPLETED: + get_xbzrle_cache_stats(info); + + info->has_status = true; + info->status = g_strdup("completed"); + info->has_total_time = true; + info->total_time = s->total_time; + info->has_downtime = true; + info->downtime = s->downtime; + info->has_setup_time = true; + info->setup_time = s->setup_time; + + info->has_ram = true; + info->ram = g_malloc0(sizeof(*info->ram)); + info->ram->transferred = ram_bytes_transferred(); + info->ram->remaining = 0; + info->ram->total = ram_bytes_total(); + info->ram->duplicate = dup_mig_pages_transferred(); + info->ram->skipped = skipped_mig_pages_transferred(); + info->ram->normal = norm_mig_pages_transferred(); + info->ram->normal_bytes = norm_mig_bytes_transferred(); + info->ram->mbps = s->mbps; + info->ram->dirty_sync_count = s->dirty_sync_count; + break; + case MIG_STATE_ERROR: + info->has_status = true; + info->status = g_strdup("failed"); + break; + case MIG_STATE_CANCELLED: + info->has_status = true; + info->status = g_strdup("cancelled"); + break; + } + + return info; +} + +void qmp_migrate_set_capabilities(MigrationCapabilityStatusList *params, + Error **errp) +{ + MigrationState *s = migrate_get_current(); + MigrationCapabilityStatusList *cap; + + if (s->state == MIG_STATE_ACTIVE || s->state == MIG_STATE_SETUP) { + error_set(errp, QERR_MIGRATION_ACTIVE); + return; + } + + for (cap = params; cap; cap = cap->next) { + s->enabled_capabilities[cap->value->capability] = cap->value->state; + } +} + +/* shared migration helpers */ + +static void migrate_set_state(MigrationState *s, int old_state, int new_state) +{ + if (atomic_cmpxchg(&s->state, old_state, new_state) == new_state) { + trace_migrate_set_state(new_state); + } +} + +static void migrate_fd_cleanup(void *opaque) +{ + MigrationState *s = opaque; + + qemu_bh_delete(s->cleanup_bh); + s->cleanup_bh = NULL; + + if (s->file) { + trace_migrate_fd_cleanup(); + qemu_mutex_unlock_iothread(); + qemu_thread_join(&s->thread); + qemu_mutex_lock_iothread(); + + qemu_fclose(s->file); + s->file = NULL; + } + + assert(s->state != MIG_STATE_ACTIVE); + + if (s->state != MIG_STATE_COMPLETED) { + qemu_savevm_state_cancel(); + if (s->state == MIG_STATE_CANCELLING) { + migrate_set_state(s, MIG_STATE_CANCELLING, MIG_STATE_CANCELLED); + } + } + + notifier_list_notify(&migration_state_notifiers, s); +} + +void migrate_fd_error(MigrationState *s) +{ + trace_migrate_fd_error(); + assert(s->file == NULL); + s->state = MIG_STATE_ERROR; + trace_migrate_set_state(MIG_STATE_ERROR); + notifier_list_notify(&migration_state_notifiers, s); +} + +static void migrate_fd_cancel(MigrationState *s) +{ + int old_state ; + trace_migrate_fd_cancel(); + + do { + old_state = s->state; + if (old_state != MIG_STATE_SETUP && old_state != MIG_STATE_ACTIVE) { + break; + } + migrate_set_state(s, old_state, MIG_STATE_CANCELLING); + } while (s->state != MIG_STATE_CANCELLING); +} + +void add_migration_state_change_notifier(Notifier *notify) +{ + notifier_list_add(&migration_state_notifiers, notify); +} + +void remove_migration_state_change_notifier(Notifier *notify) +{ + notifier_remove(notify); +} + +bool migration_in_setup(MigrationState *s) +{ + return s->state == MIG_STATE_SETUP; +} + +bool migration_has_finished(MigrationState *s) +{ + return s->state == MIG_STATE_COMPLETED; +} + +bool migration_has_failed(MigrationState *s) +{ + return (s->state == MIG_STATE_CANCELLED || + s->state == MIG_STATE_ERROR); +} + +static MigrationState *migrate_init(const MigrationParams *params) +{ + MigrationState *s = migrate_get_current(); + int64_t bandwidth_limit = s->bandwidth_limit; + bool enabled_capabilities[MIGRATION_CAPABILITY_MAX]; + int64_t xbzrle_cache_size = s->xbzrle_cache_size; + + memcpy(enabled_capabilities, s->enabled_capabilities, + sizeof(enabled_capabilities)); + + memset(s, 0, sizeof(*s)); + s->params = *params; + memcpy(s->enabled_capabilities, enabled_capabilities, + sizeof(enabled_capabilities)); + s->xbzrle_cache_size = xbzrle_cache_size; + + s->bandwidth_limit = bandwidth_limit; + s->state = MIG_STATE_SETUP; + trace_migrate_set_state(MIG_STATE_SETUP); + + s->total_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME); + return s; +} + +static GSList *migration_blockers; + +void migrate_add_blocker(Error *reason) +{ + migration_blockers = g_slist_prepend(migration_blockers, reason); +} + +void migrate_del_blocker(Error *reason) +{ + migration_blockers = g_slist_remove(migration_blockers, reason); +} + +void qmp_migrate(const char *uri, bool has_blk, bool blk, + bool has_inc, bool inc, bool has_detach, bool detach, + Error **errp) +{ + Error *local_err = NULL; + MigrationState *s = migrate_get_current(); + MigrationParams params; + const char *p; + + params.blk = has_blk && blk; + params.shared = has_inc && inc; + + if (s->state == MIG_STATE_ACTIVE || s->state == MIG_STATE_SETUP || + s->state == MIG_STATE_CANCELLING) { + error_set(errp, QERR_MIGRATION_ACTIVE); + return; + } + + if (runstate_check(RUN_STATE_INMIGRATE)) { + error_setg(errp, "Guest is waiting for an incoming migration"); + return; + } + + if (qemu_savevm_state_blocked(errp)) { + return; + } + + if (migration_blockers) { + *errp = error_copy(migration_blockers->data); + return; + } + + s = migrate_init(¶ms); + + if (strstart(uri, "tcp:", &p)) { + tcp_start_outgoing_migration(s, p, &local_err); +#ifdef CONFIG_RDMA + } else if (strstart(uri, "rdma:", &p)) { + rdma_start_outgoing_migration(s, p, &local_err); +#endif +#if !defined(WIN32) + } else if (strstart(uri, "exec:", &p)) { + exec_start_outgoing_migration(s, p, &local_err); + } else if (strstart(uri, "unix:", &p)) { + unix_start_outgoing_migration(s, p, &local_err); + } else if (strstart(uri, "fd:", &p)) { + fd_start_outgoing_migration(s, p, &local_err); +#endif + } else { + error_set(errp, QERR_INVALID_PARAMETER_VALUE, "uri", "a valid migration protocol"); + s->state = MIG_STATE_ERROR; + return; + } + + if (local_err) { + migrate_fd_error(s); + error_propagate(errp, local_err); + return; + } +} + +void qmp_migrate_cancel(Error **errp) +{ + migrate_fd_cancel(migrate_get_current()); +} + +void qmp_migrate_set_cache_size(int64_t value, Error **errp) +{ + MigrationState *s = migrate_get_current(); + int64_t new_size; + + /* Check for truncation */ + if (value != (size_t)value) { + error_set(errp, QERR_INVALID_PARAMETER_VALUE, "cache size", + "exceeding address space"); + return; + } + + /* Cache should not be larger than guest ram size */ + if (value > ram_bytes_total()) { + error_set(errp, QERR_INVALID_PARAMETER_VALUE, "cache size", + "exceeds guest ram size "); + return; + } + + new_size = xbzrle_cache_resize(value); + if (new_size < 0) { + error_set(errp, QERR_INVALID_PARAMETER_VALUE, "cache size", + "is smaller than page size"); + return; + } + + s->xbzrle_cache_size = new_size; +} + +int64_t qmp_query_migrate_cache_size(Error **errp) +{ + return migrate_xbzrle_cache_size(); +} + +void qmp_migrate_set_speed(int64_t value, Error **errp) +{ + MigrationState *s; + + if (value < 0) { + value = 0; + } + if (value > SIZE_MAX) { + value = SIZE_MAX; + } + + s = migrate_get_current(); + s->bandwidth_limit = value; + if (s->file) { + qemu_file_set_rate_limit(s->file, s->bandwidth_limit / XFER_LIMIT_RATIO); + } +} + +void qmp_migrate_set_downtime(double value, Error **errp) +{ + value *= 1e9; + value = MAX(0, MIN(UINT64_MAX, value)); + max_downtime = (uint64_t)value; +} + +bool migrate_rdma_pin_all(void) +{ + MigrationState *s; + + s = migrate_get_current(); + + return s->enabled_capabilities[MIGRATION_CAPABILITY_RDMA_PIN_ALL]; +} + +bool migrate_auto_converge(void) +{ + MigrationState *s; + + s = migrate_get_current(); + + return s->enabled_capabilities[MIGRATION_CAPABILITY_AUTO_CONVERGE]; +} + +bool migrate_zero_blocks(void) +{ + MigrationState *s; + + s = migrate_get_current(); + + return s->enabled_capabilities[MIGRATION_CAPABILITY_ZERO_BLOCKS]; +} + +int migrate_use_xbzrle(void) +{ + MigrationState *s; + + s = migrate_get_current(); + + return s->enabled_capabilities[MIGRATION_CAPABILITY_XBZRLE]; +} + +int64_t migrate_xbzrle_cache_size(void) +{ + MigrationState *s; + + s = migrate_get_current(); + + return s->xbzrle_cache_size; +} + +/* migration thread support */ + +static void *migration_thread(void *opaque) +{ + MigrationState *s = opaque; + int64_t initial_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME); + int64_t setup_start = qemu_clock_get_ms(QEMU_CLOCK_HOST); + int64_t initial_bytes = 0; + int64_t max_size = 0; + int64_t start_time = initial_time; + bool old_vm_running = false; + + qemu_savevm_state_begin(s->file, &s->params); + + s->setup_time = qemu_clock_get_ms(QEMU_CLOCK_HOST) - setup_start; + migrate_set_state(s, MIG_STATE_SETUP, MIG_STATE_ACTIVE); + + while (s->state == MIG_STATE_ACTIVE) { + int64_t current_time; + uint64_t pending_size; + + if (!qemu_file_rate_limit(s->file)) { + pending_size = qemu_savevm_state_pending(s->file, max_size); + trace_migrate_pending(pending_size, max_size); + if (pending_size && pending_size >= max_size) { + qemu_savevm_state_iterate(s->file); + } else { + int ret; + + qemu_mutex_lock_iothread(); + start_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME); + qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER); + old_vm_running = runstate_is_running(); + + ret = vm_stop_force_state(RUN_STATE_FINISH_MIGRATE); + if (ret >= 0) { + qemu_file_set_rate_limit(s->file, INT64_MAX); + qemu_savevm_state_complete(s->file); + } + qemu_mutex_unlock_iothread(); + + if (ret < 0) { + migrate_set_state(s, MIG_STATE_ACTIVE, MIG_STATE_ERROR); + break; + } + + if (!qemu_file_get_error(s->file)) { + migrate_set_state(s, MIG_STATE_ACTIVE, MIG_STATE_COMPLETED); + break; + } + } + } + + if (qemu_file_get_error(s->file)) { + migrate_set_state(s, MIG_STATE_ACTIVE, MIG_STATE_ERROR); + break; + } + current_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME); + if (current_time >= initial_time + BUFFER_DELAY) { + uint64_t transferred_bytes = qemu_ftell(s->file) - initial_bytes; + uint64_t time_spent = current_time - initial_time; + double bandwidth = transferred_bytes / time_spent; + max_size = bandwidth * migrate_max_downtime() / 1000000; + + s->mbps = time_spent ? (((double) transferred_bytes * 8.0) / + ((double) time_spent / 1000.0)) / 1000.0 / 1000.0 : -1; + + trace_migrate_transferred(transferred_bytes, time_spent, + bandwidth, max_size); + /* if we haven't sent anything, we don't want to recalculate + 10000 is a small enough number for our purposes */ + if (s->dirty_bytes_rate && transferred_bytes > 10000) { + s->expected_downtime = s->dirty_bytes_rate / bandwidth; + } + + qemu_file_reset_rate_limit(s->file); + initial_time = current_time; + initial_bytes = qemu_ftell(s->file); + } + if (qemu_file_rate_limit(s->file)) { + /* usleep expects microseconds */ + g_usleep((initial_time + BUFFER_DELAY - current_time)*1000); + } + } + + qemu_mutex_lock_iothread(); + if (s->state == MIG_STATE_COMPLETED) { + int64_t end_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME); + uint64_t transferred_bytes = qemu_ftell(s->file); + s->total_time = end_time - s->total_time; + s->downtime = end_time - start_time; + if (s->total_time) { + s->mbps = (((double) transferred_bytes * 8.0) / + ((double) s->total_time)) / 1000; + } + runstate_set(RUN_STATE_POSTMIGRATE); + } else { + if (old_vm_running) { + vm_start(); + } + } + qemu_bh_schedule(s->cleanup_bh); + qemu_mutex_unlock_iothread(); + + return NULL; +} + +void migrate_fd_connect(MigrationState *s) +{ + s->state = MIG_STATE_SETUP; + trace_migrate_set_state(MIG_STATE_SETUP); + + /* This is a best 1st approximation. ns to ms */ + s->expected_downtime = max_downtime/1000000; + s->cleanup_bh = qemu_bh_new(migrate_fd_cleanup, s); + + qemu_file_set_rate_limit(s->file, + s->bandwidth_limit / XFER_LIMIT_RATIO); + + /* Notify before starting migration thread */ + notifier_list_notify(&migration_state_notifiers, s); + + qemu_thread_create(&s->thread, "migration", migration_thread, s, + QEMU_THREAD_JOINABLE); +} |