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Diffstat (limited to 'src/migration/migration.c')
| -rw-r--r-- | src/migration/migration.c | 1773 |
1 files changed, 1773 insertions, 0 deletions
diff --git a/src/migration/migration.c b/src/migration/migration.c new file mode 100644 index 0000000..adc6b6f --- /dev/null +++ b/src/migration/migration.c @@ -0,0 +1,1773 @@ +/* + * 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/error-report.h" +#include "qemu/main-loop.h" +#include "migration/migration.h" +#include "migration/qemu-file.h" +#include "sysemu/sysemu.h" +#include "block/block.h" +#include "qapi/qmp/qerror.h" +#include "qapi/util.h" +#include "qemu/sockets.h" +#include "qemu/rcu.h" +#include "migration/block.h" +#include "migration/postcopy-ram.h" +#include "qemu/thread.h" +#include "qmp-commands.h" +#include "trace.h" +#include "qapi-event.h" +#include "qom/cpu.h" +#include "exec/memory.h" +#include "exec/address-spaces.h" + +#define MAX_THROTTLE (32 << 20) /* Migration transfer 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) + +/* Default compression thread count */ +#define DEFAULT_MIGRATE_COMPRESS_THREAD_COUNT 8 +/* Default decompression thread count, usually decompression is at + * least 4 times as fast as compression.*/ +#define DEFAULT_MIGRATE_DECOMPRESS_THREAD_COUNT 2 +/*0: means nocompress, 1: best speed, ... 9: best compress ratio */ +#define DEFAULT_MIGRATE_COMPRESS_LEVEL 1 +/* Define default autoconverge cpu throttle migration parameters */ +#define DEFAULT_MIGRATE_X_CPU_THROTTLE_INITIAL 20 +#define DEFAULT_MIGRATE_X_CPU_THROTTLE_INCREMENT 10 + +/* Migration XBZRLE default cache size */ +#define DEFAULT_MIGRATE_CACHE_SIZE (64 * 1024 * 1024) + +static NotifierList migration_state_notifiers = + NOTIFIER_LIST_INITIALIZER(migration_state_notifiers); + +static bool deferred_incoming; + +/* + * Current state of incoming postcopy; note this is not part of + * MigrationIncomingState since it's state is used during cleanup + * at the end as MIS is being freed. + */ +static PostcopyState incoming_postcopy_state; + +/* When we add fault tolerance, we could have several + migrations at once. For now we don't need to add + dynamic creation of migration */ + +/* For outgoing */ +MigrationState *migrate_get_current(void) +{ + static bool once; + static MigrationState current_migration = { + .state = MIGRATION_STATUS_NONE, + .bandwidth_limit = MAX_THROTTLE, + .xbzrle_cache_size = DEFAULT_MIGRATE_CACHE_SIZE, + .mbps = -1, + .parameters[MIGRATION_PARAMETER_COMPRESS_LEVEL] = + DEFAULT_MIGRATE_COMPRESS_LEVEL, + .parameters[MIGRATION_PARAMETER_COMPRESS_THREADS] = + DEFAULT_MIGRATE_COMPRESS_THREAD_COUNT, + .parameters[MIGRATION_PARAMETER_DECOMPRESS_THREADS] = + DEFAULT_MIGRATE_DECOMPRESS_THREAD_COUNT, + .parameters[MIGRATION_PARAMETER_X_CPU_THROTTLE_INITIAL] = + DEFAULT_MIGRATE_X_CPU_THROTTLE_INITIAL, + .parameters[MIGRATION_PARAMETER_X_CPU_THROTTLE_INCREMENT] = + DEFAULT_MIGRATE_X_CPU_THROTTLE_INCREMENT, + }; + + if (!once) { + qemu_mutex_init(¤t_migration.src_page_req_mutex); + once = true; + } + return ¤t_migration; +} + +/* For incoming */ +static MigrationIncomingState *mis_current; + +MigrationIncomingState *migration_incoming_get_current(void) +{ + return mis_current; +} + +MigrationIncomingState *migration_incoming_state_new(QEMUFile* f) +{ + mis_current = g_new0(MigrationIncomingState, 1); + mis_current->from_src_file = f; + QLIST_INIT(&mis_current->loadvm_handlers); + qemu_mutex_init(&mis_current->rp_mutex); + qemu_event_init(&mis_current->main_thread_load_event, false); + + return mis_current; +} + +void migration_incoming_state_destroy(void) +{ + qemu_event_destroy(&mis_current->main_thread_load_event); + loadvm_free_handlers(mis_current); + g_free(mis_current); + mis_current = NULL; +} + + +typedef struct { + bool optional; + uint32_t size; + uint8_t runstate[100]; + RunState state; + bool received; +} GlobalState; + +static GlobalState global_state; + +int global_state_store(void) +{ + if (!runstate_store((char *)global_state.runstate, + sizeof(global_state.runstate))) { + error_report("runstate name too big: %s", global_state.runstate); + trace_migrate_state_too_big(); + return -EINVAL; + } + return 0; +} + +void global_state_store_running(void) +{ + const char *state = RunState_lookup[RUN_STATE_RUNNING]; + strncpy((char *)global_state.runstate, + state, sizeof(global_state.runstate)); +} + +static bool global_state_received(void) +{ + return global_state.received; +} + +static RunState global_state_get_runstate(void) +{ + return global_state.state; +} + +void global_state_set_optional(void) +{ + global_state.optional = true; +} + +static bool global_state_needed(void *opaque) +{ + GlobalState *s = opaque; + char *runstate = (char *)s->runstate; + + /* If it is not optional, it is mandatory */ + + if (s->optional == false) { + return true; + } + + /* If state is running or paused, it is not needed */ + + if (strcmp(runstate, "running") == 0 || + strcmp(runstate, "paused") == 0) { + return false; + } + + /* for any other state it is needed */ + return true; +} + +static int global_state_post_load(void *opaque, int version_id) +{ + GlobalState *s = opaque; + Error *local_err = NULL; + int r; + char *runstate = (char *)s->runstate; + + s->received = true; + trace_migrate_global_state_post_load(runstate); + + r = qapi_enum_parse(RunState_lookup, runstate, RUN_STATE_MAX, + -1, &local_err); + + if (r == -1) { + if (local_err) { + error_report_err(local_err); + } + return -EINVAL; + } + s->state = r; + + return 0; +} + +static void global_state_pre_save(void *opaque) +{ + GlobalState *s = opaque; + + trace_migrate_global_state_pre_save((char *)s->runstate); + s->size = strlen((char *)s->runstate) + 1; +} + +static const VMStateDescription vmstate_globalstate = { + .name = "globalstate", + .version_id = 1, + .minimum_version_id = 1, + .post_load = global_state_post_load, + .pre_save = global_state_pre_save, + .needed = global_state_needed, + .fields = (VMStateField[]) { + VMSTATE_UINT32(size, GlobalState), + VMSTATE_BUFFER(runstate, GlobalState), + VMSTATE_END_OF_LIST() + }, +}; + +void register_global_state(void) +{ + /* We would use it independently that we receive it */ + strcpy((char *)&global_state.runstate, ""); + global_state.received = false; + vmstate_register(NULL, 0, &vmstate_globalstate, &global_state); +} + +static void migrate_generate_event(int new_state) +{ + if (migrate_use_events()) { + qapi_event_send_migration(new_state, &error_abort); + } +} + +/* + * Called on -incoming with a defer: uri. + * The migration can be started later after any parameters have been + * changed. + */ +static void deferred_incoming_migration(Error **errp) +{ + if (deferred_incoming) { + error_setg(errp, "Incoming migration already deferred"); + } + deferred_incoming = true; +} + +/* Request a range of pages from the source VM at the given + * start address. + * rbname: Name of the RAMBlock to request the page in, if NULL it's the same + * as the last request (a name must have been given previously) + * Start: Address offset within the RB + * Len: Length in bytes required - must be a multiple of pagesize + */ +void migrate_send_rp_req_pages(MigrationIncomingState *mis, const char *rbname, + ram_addr_t start, size_t len) +{ + uint8_t bufc[12 + 1 + 255]; /* start (8), len (4), rbname upto 256 */ + size_t msglen = 12; /* start + len */ + + *(uint64_t *)bufc = cpu_to_be64((uint64_t)start); + *(uint32_t *)(bufc + 8) = cpu_to_be32((uint32_t)len); + + if (rbname) { + int rbname_len = strlen(rbname); + assert(rbname_len < 256); + + bufc[msglen++] = rbname_len; + memcpy(bufc + msglen, rbname, rbname_len); + msglen += rbname_len; + migrate_send_rp_message(mis, MIG_RP_MSG_REQ_PAGES_ID, msglen, bufc); + } else { + migrate_send_rp_message(mis, MIG_RP_MSG_REQ_PAGES, msglen, bufc); + } +} + +void qemu_start_incoming_migration(const char *uri, Error **errp) +{ + const char *p; + + qapi_event_send_migration(MIGRATION_STATUS_SETUP, &error_abort); + if (!strcmp(uri, "defer")) { + deferred_incoming_migration(errp); + } else 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; + MigrationIncomingState *mis; + PostcopyState ps; + int ret; + + mis = migration_incoming_state_new(f); + postcopy_state_set(POSTCOPY_INCOMING_NONE); + migrate_generate_event(MIGRATION_STATUS_ACTIVE); + + ret = qemu_loadvm_state(f); + + ps = postcopy_state_get(); + trace_process_incoming_migration_co_end(ret, ps); + if (ps != POSTCOPY_INCOMING_NONE) { + if (ps == POSTCOPY_INCOMING_ADVISE) { + /* + * Where a migration had postcopy enabled (and thus went to advise) + * but managed to complete within the precopy period, we can use + * the normal exit. + */ + postcopy_ram_incoming_cleanup(mis); + } else if (ret >= 0) { + /* + * Postcopy was started, cleanup should happen at the end of the + * postcopy thread. + */ + trace_process_incoming_migration_co_postcopy_end_main(); + return; + } + /* Else if something went wrong then just fall out of the normal exit */ + } + + qemu_fclose(f); + free_xbzrle_decoded_buf(); + migration_incoming_state_destroy(); + + if (ret < 0) { + migrate_generate_event(MIGRATION_STATUS_FAILED); + error_report("load of migration failed: %s", strerror(-ret)); + migrate_decompress_threads_join(); + exit(EXIT_FAILURE); + } + + /* Make sure all file formats flush their mutable metadata */ + bdrv_invalidate_cache_all(&local_err); + if (local_err) { + migrate_generate_event(MIGRATION_STATUS_FAILED); + error_report_err(local_err); + migrate_decompress_threads_join(); + exit(EXIT_FAILURE); + } + + /* + * This must happen after all error conditions are dealt with and + * we're sure the VM is going to be running on this host. + */ + qemu_announce_self(); + + /* If global state section was not received or we are in running + state, we need to obey autostart. Any other state is set with + runstate_set. */ + + if (!global_state_received() || + global_state_get_runstate() == RUN_STATE_RUNNING) { + if (autostart) { + vm_start(); + } else { + runstate_set(RUN_STATE_PAUSED); + } + } else { + runstate_set(global_state_get_runstate()); + } + migrate_decompress_threads_join(); + /* + * This must happen after any state changes since as soon as an external + * observer sees this event they might start to prod at the VM assuming + * it's ready to use. + */ + migrate_generate_event(MIGRATION_STATUS_COMPLETED); +} + +void process_incoming_migration(QEMUFile *f) +{ + Coroutine *co = qemu_coroutine_create(process_incoming_migration_co); + int fd = qemu_get_fd(f); + + assert(fd != -1); + migrate_decompress_threads_create(); + qemu_set_nonblock(fd); + qemu_coroutine_enter(co, f); +} + +/* + * Send a message on the return channel back to the source + * of the migration. + */ +void migrate_send_rp_message(MigrationIncomingState *mis, + enum mig_rp_message_type message_type, + uint16_t len, void *data) +{ + trace_migrate_send_rp_message((int)message_type, len); + qemu_mutex_lock(&mis->rp_mutex); + qemu_put_be16(mis->to_src_file, (unsigned int)message_type); + qemu_put_be16(mis->to_src_file, len); + qemu_put_buffer(mis->to_src_file, data, len); + qemu_fflush(mis->to_src_file); + qemu_mutex_unlock(&mis->rp_mutex); +} + +/* + * Send a 'SHUT' message on the return channel with the given value + * to indicate that we've finished with the RP. Non-0 value indicates + * error. + */ +void migrate_send_rp_shut(MigrationIncomingState *mis, + uint32_t value) +{ + uint32_t buf; + + buf = cpu_to_be32(value); + migrate_send_rp_message(mis, MIG_RP_MSG_SHUT, sizeof(buf), &buf); +} + +/* + * Send a 'PONG' message on the return channel with the given value + * (normally in response to a 'PING') + */ +void migrate_send_rp_pong(MigrationIncomingState *mis, + uint32_t value) +{ + uint32_t buf; + + buf = cpu_to_be32(value); + migrate_send_rp_message(mis, MIG_RP_MSG_PONG, sizeof(buf), &buf); +} + +/* 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; +} + +MigrationParameters *qmp_query_migrate_parameters(Error **errp) +{ + MigrationParameters *params; + MigrationState *s = migrate_get_current(); + + params = g_malloc0(sizeof(*params)); + params->compress_level = s->parameters[MIGRATION_PARAMETER_COMPRESS_LEVEL]; + params->compress_threads = + s->parameters[MIGRATION_PARAMETER_COMPRESS_THREADS]; + params->decompress_threads = + s->parameters[MIGRATION_PARAMETER_DECOMPRESS_THREADS]; + params->x_cpu_throttle_initial = + s->parameters[MIGRATION_PARAMETER_X_CPU_THROTTLE_INITIAL]; + params->x_cpu_throttle_increment = + s->parameters[MIGRATION_PARAMETER_X_CPU_THROTTLE_INCREMENT]; + + return params; +} + +/* + * Return true if we're already in the middle of a migration + * (i.e. any of the active or setup states) + */ +static bool migration_is_setup_or_active(int state) +{ + switch (state) { + case MIGRATION_STATUS_ACTIVE: + case MIGRATION_STATUS_POSTCOPY_ACTIVE: + case MIGRATION_STATUS_SETUP: + return true; + + default: + return false; + + } +} + +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 MIGRATION_STATUS_NONE: + /* no migration has happened ever */ + break; + case MIGRATION_STATUS_SETUP: + info->has_status = true; + info->has_total_time = false; + break; + case MIGRATION_STATUS_ACTIVE: + case MIGRATION_STATUS_CANCELLING: + info->has_status = true; + 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(); + } + + if (cpu_throttle_active()) { + info->has_x_cpu_throttle_percentage = true; + info->x_cpu_throttle_percentage = cpu_throttle_get_percentage(); + } + + get_xbzrle_cache_stats(info); + break; + case MIGRATION_STATUS_POSTCOPY_ACTIVE: + /* Mostly the same as active; TODO add some postcopy stats */ + info->has_status = true; + 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; + + 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 MIGRATION_STATUS_COMPLETED: + get_xbzrle_cache_stats(info); + + info->has_status = true; + 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 MIGRATION_STATUS_FAILED: + info->has_status = true; + break; + case MIGRATION_STATUS_CANCELLED: + info->has_status = true; + break; + } + info->status = s->state; + + return info; +} + +void qmp_migrate_set_capabilities(MigrationCapabilityStatusList *params, + Error **errp) +{ + MigrationState *s = migrate_get_current(); + MigrationCapabilityStatusList *cap; + + if (migration_is_setup_or_active(s->state)) { + error_setg(errp, QERR_MIGRATION_ACTIVE); + return; + } + + for (cap = params; cap; cap = cap->next) { + s->enabled_capabilities[cap->value->capability] = cap->value->state; + } + + if (migrate_postcopy_ram()) { + if (migrate_use_compression()) { + /* The decompression threads asynchronously write into RAM + * rather than use the atomic copies needed to avoid + * userfaulting. It should be possible to fix the decompression + * threads for compatibility in future. + */ + error_report("Postcopy is not currently compatible with " + "compression"); + s->enabled_capabilities[MIGRATION_CAPABILITY_X_POSTCOPY_RAM] = + false; + } + } +} + +void qmp_migrate_set_parameters(bool has_compress_level, + int64_t compress_level, + bool has_compress_threads, + int64_t compress_threads, + bool has_decompress_threads, + int64_t decompress_threads, + bool has_x_cpu_throttle_initial, + int64_t x_cpu_throttle_initial, + bool has_x_cpu_throttle_increment, + int64_t x_cpu_throttle_increment, Error **errp) +{ + MigrationState *s = migrate_get_current(); + + if (has_compress_level && (compress_level < 0 || compress_level > 9)) { + error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "compress_level", + "is invalid, it should be in the range of 0 to 9"); + return; + } + if (has_compress_threads && + (compress_threads < 1 || compress_threads > 255)) { + error_setg(errp, QERR_INVALID_PARAMETER_VALUE, + "compress_threads", + "is invalid, it should be in the range of 1 to 255"); + return; + } + if (has_decompress_threads && + (decompress_threads < 1 || decompress_threads > 255)) { + error_setg(errp, QERR_INVALID_PARAMETER_VALUE, + "decompress_threads", + "is invalid, it should be in the range of 1 to 255"); + return; + } + if (has_x_cpu_throttle_initial && + (x_cpu_throttle_initial < 1 || x_cpu_throttle_initial > 99)) { + error_setg(errp, QERR_INVALID_PARAMETER_VALUE, + "x_cpu_throttle_initial", + "an integer in the range of 1 to 99"); + } + if (has_x_cpu_throttle_increment && + (x_cpu_throttle_increment < 1 || x_cpu_throttle_increment > 99)) { + error_setg(errp, QERR_INVALID_PARAMETER_VALUE, + "x_cpu_throttle_increment", + "an integer in the range of 1 to 99"); + } + + if (has_compress_level) { + s->parameters[MIGRATION_PARAMETER_COMPRESS_LEVEL] = compress_level; + } + if (has_compress_threads) { + s->parameters[MIGRATION_PARAMETER_COMPRESS_THREADS] = compress_threads; + } + if (has_decompress_threads) { + s->parameters[MIGRATION_PARAMETER_DECOMPRESS_THREADS] = + decompress_threads; + } + if (has_x_cpu_throttle_initial) { + s->parameters[MIGRATION_PARAMETER_X_CPU_THROTTLE_INITIAL] = + x_cpu_throttle_initial; + } + + if (has_x_cpu_throttle_increment) { + s->parameters[MIGRATION_PARAMETER_X_CPU_THROTTLE_INCREMENT] = + x_cpu_throttle_increment; + } +} + +void qmp_migrate_start_postcopy(Error **errp) +{ + MigrationState *s = migrate_get_current(); + + if (!migrate_postcopy_ram()) { + error_setg(errp, "Enable postcopy with migrate_set_capability before" + " the start of migration"); + return; + } + + if (s->state == MIGRATION_STATUS_NONE) { + error_setg(errp, "Postcopy must be started after migration has been" + " started"); + return; + } + /* + * we don't error if migration has finished since that would be racy + * with issuing this command. + */ + atomic_set(&s->start_postcopy, true); +} + +/* 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) == old_state) { + trace_migrate_set_state(new_state); + migrate_generate_event(new_state); + } +} + +static void migrate_fd_cleanup(void *opaque) +{ + MigrationState *s = opaque; + + qemu_bh_delete(s->cleanup_bh); + s->cleanup_bh = NULL; + + flush_page_queue(s); + + if (s->file) { + trace_migrate_fd_cleanup(); + qemu_mutex_unlock_iothread(); + if (s->migration_thread_running) { + qemu_thread_join(&s->thread); + s->migration_thread_running = false; + } + qemu_mutex_lock_iothread(); + + migrate_compress_threads_join(); + qemu_fclose(s->file); + s->file = NULL; + } + + assert((s->state != MIGRATION_STATUS_ACTIVE) && + (s->state != MIGRATION_STATUS_POSTCOPY_ACTIVE)); + + if (s->state == MIGRATION_STATUS_CANCELLING) { + migrate_set_state(s, MIGRATION_STATUS_CANCELLING, + MIGRATION_STATUS_CANCELLED); + } + + notifier_list_notify(&migration_state_notifiers, s); +} + +void migrate_fd_error(MigrationState *s) +{ + trace_migrate_fd_error(); + assert(s->file == NULL); + migrate_set_state(s, MIGRATION_STATUS_SETUP, MIGRATION_STATUS_FAILED); + notifier_list_notify(&migration_state_notifiers, s); +} + +static void migrate_fd_cancel(MigrationState *s) +{ + int old_state ; + QEMUFile *f = migrate_get_current()->file; + trace_migrate_fd_cancel(); + + if (s->rp_state.from_dst_file) { + /* shutdown the rp socket, so causing the rp thread to shutdown */ + qemu_file_shutdown(s->rp_state.from_dst_file); + } + + do { + old_state = s->state; + if (!migration_is_setup_or_active(old_state)) { + break; + } + migrate_set_state(s, old_state, MIGRATION_STATUS_CANCELLING); + } while (s->state != MIGRATION_STATUS_CANCELLING); + + /* + * If we're unlucky the migration code might be stuck somewhere in a + * send/write while the network has failed and is waiting to timeout; + * if we've got shutdown(2) available then we can force it to quit. + * The outgoing qemu file gets closed in migrate_fd_cleanup that is + * called in a bh, so there is no race against this cancel. + */ + if (s->state == MIGRATION_STATUS_CANCELLING && f) { + qemu_file_shutdown(f); + } +} + +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 == MIGRATION_STATUS_SETUP; +} + +bool migration_has_finished(MigrationState *s) +{ + return s->state == MIGRATION_STATUS_COMPLETED; +} + +bool migration_has_failed(MigrationState *s) +{ + return (s->state == MIGRATION_STATUS_CANCELLED || + s->state == MIGRATION_STATUS_FAILED); +} + +bool migration_in_postcopy(MigrationState *s) +{ + return (s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE); +} + +MigrationState *migrate_init(const MigrationParams *params) +{ + MigrationState *s = migrate_get_current(); + + /* + * Reinitialise all migration state, except + * parameters/capabilities that the user set, and + * locks. + */ + s->bytes_xfer = 0; + s->xfer_limit = 0; + s->cleanup_bh = 0; + s->file = NULL; + s->state = MIGRATION_STATUS_NONE; + s->params = *params; + s->rp_state.from_dst_file = NULL; + s->rp_state.error = false; + s->mbps = 0.0; + s->downtime = 0; + s->expected_downtime = 0; + s->dirty_pages_rate = 0; + s->dirty_bytes_rate = 0; + s->setup_time = 0; + s->dirty_sync_count = 0; + s->start_postcopy = false; + s->migration_thread_running = false; + s->last_req_rb = NULL; + + migrate_set_state(s, MIGRATION_STATUS_NONE, MIGRATION_STATUS_SETUP); + + QSIMPLEQ_INIT(&s->src_page_requests); + + 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_incoming(const char *uri, Error **errp) +{ + Error *local_err = NULL; + static bool once = true; + + if (!deferred_incoming) { + error_setg(errp, "For use with '-incoming defer'"); + return; + } + if (!once) { + error_setg(errp, "The incoming migration has already been started"); + } + + qemu_start_incoming_migration(uri, &local_err); + + if (local_err) { + error_propagate(errp, local_err); + return; + } + + once = false; +} + +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 (migration_is_setup_or_active(s->state) || + s->state == MIGRATION_STATUS_CANCELLING) { + error_setg(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; + } + + /* We are starting a new migration, so we want to start in a clean + state. This change is only needed if previous migration + failed/was cancelled. We don't use migrate_set_state() because + we are setting the initial state, not changing it. */ + s->state = MIGRATION_STATUS_NONE; + + 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_setg(errp, QERR_INVALID_PARAMETER_VALUE, "uri", + "a valid migration protocol"); + migrate_set_state(s, MIGRATION_STATUS_SETUP, MIGRATION_STATUS_FAILED); + 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_setg(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_setg(errp, QERR_INVALID_PARAMETER_VALUE, "cache size", + "exceeds guest ram size "); + return; + } + + new_size = xbzrle_cache_resize(value); + if (new_size < 0) { + error_setg(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_postcopy_ram(void) +{ + MigrationState *s; + + s = migrate_get_current(); + + return s->enabled_capabilities[MIGRATION_CAPABILITY_X_POSTCOPY_RAM]; +} + +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]; +} + +bool migrate_use_compression(void) +{ + MigrationState *s; + + s = migrate_get_current(); + + return s->enabled_capabilities[MIGRATION_CAPABILITY_COMPRESS]; +} + +int migrate_compress_level(void) +{ + MigrationState *s; + + s = migrate_get_current(); + + return s->parameters[MIGRATION_PARAMETER_COMPRESS_LEVEL]; +} + +int migrate_compress_threads(void) +{ + MigrationState *s; + + s = migrate_get_current(); + + return s->parameters[MIGRATION_PARAMETER_COMPRESS_THREADS]; +} + +int migrate_decompress_threads(void) +{ + MigrationState *s; + + s = migrate_get_current(); + + return s->parameters[MIGRATION_PARAMETER_DECOMPRESS_THREADS]; +} + +bool migrate_use_events(void) +{ + MigrationState *s; + + s = migrate_get_current(); + + return s->enabled_capabilities[MIGRATION_CAPABILITY_EVENTS]; +} + +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 */ +/* + * Something bad happened to the RP stream, mark an error + * The caller shall print or trace something to indicate why + */ +static void mark_source_rp_bad(MigrationState *s) +{ + s->rp_state.error = true; +} + +static struct rp_cmd_args { + ssize_t len; /* -1 = variable */ + const char *name; +} rp_cmd_args[] = { + [MIG_RP_MSG_INVALID] = { .len = -1, .name = "INVALID" }, + [MIG_RP_MSG_SHUT] = { .len = 4, .name = "SHUT" }, + [MIG_RP_MSG_PONG] = { .len = 4, .name = "PONG" }, + [MIG_RP_MSG_REQ_PAGES] = { .len = 12, .name = "REQ_PAGES" }, + [MIG_RP_MSG_REQ_PAGES_ID] = { .len = -1, .name = "REQ_PAGES_ID" }, + [MIG_RP_MSG_MAX] = { .len = -1, .name = "MAX" }, +}; + +/* + * Process a request for pages received on the return path, + * We're allowed to send more than requested (e.g. to round to our page size) + * and we don't need to send pages that have already been sent. + */ +static void migrate_handle_rp_req_pages(MigrationState *ms, const char* rbname, + ram_addr_t start, size_t len) +{ + long our_host_ps = getpagesize(); + + trace_migrate_handle_rp_req_pages(rbname, start, len); + + /* + * Since we currently insist on matching page sizes, just sanity check + * we're being asked for whole host pages. + */ + if (start & (our_host_ps-1) || + (len & (our_host_ps-1))) { + error_report("%s: Misaligned page request, start: " RAM_ADDR_FMT + " len: %zd", __func__, start, len); + mark_source_rp_bad(ms); + return; + } + + if (ram_save_queue_pages(ms, rbname, start, len)) { + mark_source_rp_bad(ms); + } +} + +/* + * Handles messages sent on the return path towards the source VM + * + */ +static void *source_return_path_thread(void *opaque) +{ + MigrationState *ms = opaque; + QEMUFile *rp = ms->rp_state.from_dst_file; + uint16_t header_len, header_type; + const int max_len = 512; + uint8_t buf[max_len]; + uint32_t tmp32, sibling_error; + ram_addr_t start = 0; /* =0 to silence warning */ + size_t len = 0, expected_len; + int res; + + trace_source_return_path_thread_entry(); + while (!ms->rp_state.error && !qemu_file_get_error(rp) && + migration_is_setup_or_active(ms->state)) { + trace_source_return_path_thread_loop_top(); + header_type = qemu_get_be16(rp); + header_len = qemu_get_be16(rp); + + if (header_type >= MIG_RP_MSG_MAX || + header_type == MIG_RP_MSG_INVALID) { + error_report("RP: Received invalid message 0x%04x length 0x%04x", + header_type, header_len); + mark_source_rp_bad(ms); + goto out; + } + + if ((rp_cmd_args[header_type].len != -1 && + header_len != rp_cmd_args[header_type].len) || + header_len > max_len) { + error_report("RP: Received '%s' message (0x%04x) with" + "incorrect length %d expecting %zu", + rp_cmd_args[header_type].name, header_type, header_len, + (size_t)rp_cmd_args[header_type].len); + mark_source_rp_bad(ms); + goto out; + } + + /* We know we've got a valid header by this point */ + res = qemu_get_buffer(rp, buf, header_len); + if (res != header_len) { + error_report("RP: Failed reading data for message 0x%04x" + " read %d expected %d", + header_type, res, header_len); + mark_source_rp_bad(ms); + goto out; + } + + /* OK, we have the message and the data */ + switch (header_type) { + case MIG_RP_MSG_SHUT: + sibling_error = be32_to_cpup((uint32_t *)buf); + trace_source_return_path_thread_shut(sibling_error); + if (sibling_error) { + error_report("RP: Sibling indicated error %d", sibling_error); + mark_source_rp_bad(ms); + } + /* + * We'll let the main thread deal with closing the RP + * we could do a shutdown(2) on it, but we're the only user + * anyway, so there's nothing gained. + */ + goto out; + + case MIG_RP_MSG_PONG: + tmp32 = be32_to_cpup((uint32_t *)buf); + trace_source_return_path_thread_pong(tmp32); + break; + + case MIG_RP_MSG_REQ_PAGES: + start = be64_to_cpup((uint64_t *)buf); + len = be32_to_cpup((uint32_t *)(buf + 8)); + migrate_handle_rp_req_pages(ms, NULL, start, len); + break; + + case MIG_RP_MSG_REQ_PAGES_ID: + expected_len = 12 + 1; /* header + termination */ + + if (header_len >= expected_len) { + start = be64_to_cpup((uint64_t *)buf); + len = be32_to_cpup((uint32_t *)(buf + 8)); + /* Now we expect an idstr */ + tmp32 = buf[12]; /* Length of the following idstr */ + buf[13 + tmp32] = '\0'; + expected_len += tmp32; + } + if (header_len != expected_len) { + error_report("RP: Req_Page_id with length %d expecting %zd", + header_len, expected_len); + mark_source_rp_bad(ms); + goto out; + } + migrate_handle_rp_req_pages(ms, (char *)&buf[13], start, len); + break; + + default: + break; + } + } + if (qemu_file_get_error(rp)) { + trace_source_return_path_thread_bad_end(); + mark_source_rp_bad(ms); + } + + trace_source_return_path_thread_end(); +out: + ms->rp_state.from_dst_file = NULL; + qemu_fclose(rp); + return NULL; +} + +static int open_return_path_on_source(MigrationState *ms) +{ + + ms->rp_state.from_dst_file = qemu_file_get_return_path(ms->file); + if (!ms->rp_state.from_dst_file) { + return -1; + } + + trace_open_return_path_on_source(); + qemu_thread_create(&ms->rp_state.rp_thread, "return path", + source_return_path_thread, ms, QEMU_THREAD_JOINABLE); + + trace_open_return_path_on_source_continue(); + + return 0; +} + +/* Returns 0 if the RP was ok, otherwise there was an error on the RP */ +static int await_return_path_close_on_source(MigrationState *ms) +{ + /* + * If this is a normal exit then the destination will send a SHUT and the + * rp_thread will exit, however if there's an error we need to cause + * it to exit. + */ + if (qemu_file_get_error(ms->file) && ms->rp_state.from_dst_file) { + /* + * shutdown(2), if we have it, will cause it to unblock if it's stuck + * waiting for the destination. + */ + qemu_file_shutdown(ms->rp_state.from_dst_file); + mark_source_rp_bad(ms); + } + trace_await_return_path_close_on_source_joining(); + qemu_thread_join(&ms->rp_state.rp_thread); + trace_await_return_path_close_on_source_close(); + return ms->rp_state.error; +} + +/* + * Switch from normal iteration to postcopy + * Returns non-0 on error + */ +static int postcopy_start(MigrationState *ms, bool *old_vm_running) +{ + int ret; + const QEMUSizedBuffer *qsb; + int64_t time_at_stop = qemu_clock_get_ms(QEMU_CLOCK_REALTIME); + migrate_set_state(ms, MIGRATION_STATUS_ACTIVE, + MIGRATION_STATUS_POSTCOPY_ACTIVE); + + trace_postcopy_start(); + qemu_mutex_lock_iothread(); + trace_postcopy_start_set_run(); + + qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER); + *old_vm_running = runstate_is_running(); + global_state_store(); + ret = vm_stop_force_state(RUN_STATE_FINISH_MIGRATE); + + if (ret < 0) { + goto fail; + } + + /* + * Cause any non-postcopiable, but iterative devices to + * send out their final data. + */ + qemu_savevm_state_complete_precopy(ms->file, true); + + /* + * in Finish migrate and with the io-lock held everything should + * be quiet, but we've potentially still got dirty pages and we + * need to tell the destination to throw any pages it's already received + * that are dirty + */ + if (ram_postcopy_send_discard_bitmap(ms)) { + error_report("postcopy send discard bitmap failed"); + goto fail; + } + + /* + * send rest of state - note things that are doing postcopy + * will notice we're in POSTCOPY_ACTIVE and not actually + * wrap their state up here + */ + qemu_file_set_rate_limit(ms->file, INT64_MAX); + /* Ping just for debugging, helps line traces up */ + qemu_savevm_send_ping(ms->file, 2); + + /* + * While loading the device state we may trigger page transfer + * requests and the fd must be free to process those, and thus + * the destination must read the whole device state off the fd before + * it starts processing it. Unfortunately the ad-hoc migration format + * doesn't allow the destination to know the size to read without fully + * parsing it through each devices load-state code (especially the open + * coded devices that use get/put). + * So we wrap the device state up in a package with a length at the start; + * to do this we use a qemu_buf to hold the whole of the device state. + */ + QEMUFile *fb = qemu_bufopen("w", NULL); + if (!fb) { + error_report("Failed to create buffered file"); + goto fail; + } + + /* + * Make sure the receiver can get incoming pages before we send the rest + * of the state + */ + qemu_savevm_send_postcopy_listen(fb); + + qemu_savevm_state_complete_precopy(fb, false); + qemu_savevm_send_ping(fb, 3); + + qemu_savevm_send_postcopy_run(fb); + + /* <><> end of stuff going into the package */ + qsb = qemu_buf_get(fb); + + /* Now send that blob */ + if (qemu_savevm_send_packaged(ms->file, qsb)) { + goto fail_closefb; + } + qemu_fclose(fb); + ms->downtime = qemu_clock_get_ms(QEMU_CLOCK_REALTIME) - time_at_stop; + + qemu_mutex_unlock_iothread(); + + /* + * Although this ping is just for debug, it could potentially be + * used for getting a better measurement of downtime at the source. + */ + qemu_savevm_send_ping(ms->file, 4); + + ret = qemu_file_get_error(ms->file); + if (ret) { + error_report("postcopy_start: Migration stream errored"); + migrate_set_state(ms, MIGRATION_STATUS_POSTCOPY_ACTIVE, + MIGRATION_STATUS_FAILED); + } + + return ret; + +fail_closefb: + qemu_fclose(fb); +fail: + migrate_set_state(ms, MIGRATION_STATUS_POSTCOPY_ACTIVE, + MIGRATION_STATUS_FAILED); + qemu_mutex_unlock_iothread(); + return -1; +} + +/** + * migration_completion: Used by migration_thread when there's not much left. + * The caller 'breaks' the loop when this returns. + * + * @s: Current migration state + * @current_active_state: The migration state we expect to be in + * @*old_vm_running: Pointer to old_vm_running flag + * @*start_time: Pointer to time to update + */ +static void migration_completion(MigrationState *s, int current_active_state, + bool *old_vm_running, + int64_t *start_time) +{ + int ret; + + if (s->state == MIGRATION_STATUS_ACTIVE) { + 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 = global_state_store(); + + if (!ret) { + 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_precopy(s->file, false); + } + } + qemu_mutex_unlock_iothread(); + + if (ret < 0) { + goto fail; + } + } else if (s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE) { + trace_migration_completion_postcopy_end(); + + qemu_savevm_state_complete_postcopy(s->file); + trace_migration_completion_postcopy_end_after_complete(); + } + + /* + * If rp was opened we must clean up the thread before + * cleaning everything else up (since if there are no failures + * it will wait for the destination to send it's status in + * a SHUT command). + * Postcopy opens rp if enabled (even if it's not avtivated) + */ + if (migrate_postcopy_ram()) { + int rp_error; + trace_migration_completion_postcopy_end_before_rp(); + rp_error = await_return_path_close_on_source(s); + trace_migration_completion_postcopy_end_after_rp(rp_error); + if (rp_error) { + goto fail; + } + } + + if (qemu_file_get_error(s->file)) { + trace_migration_completion_file_err(); + goto fail; + } + + migrate_set_state(s, current_active_state, MIGRATION_STATUS_COMPLETED); + return; + +fail: + migrate_set_state(s, current_active_state, MIGRATION_STATUS_FAILED); +} + +/* + * Master migration thread on the source VM. + * It drives the migration and pumps the data down the outgoing channel. + */ +static void *migration_thread(void *opaque) +{ + MigrationState *s = opaque; + /* Used by the bandwidth calcs, updated later */ + 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; + int64_t end_time; + bool old_vm_running = false; + bool entered_postcopy = false; + /* The active state we expect to be in; ACTIVE or POSTCOPY_ACTIVE */ + enum MigrationStatus current_active_state = MIGRATION_STATUS_ACTIVE; + + rcu_register_thread(); + + qemu_savevm_state_header(s->file); + + if (migrate_postcopy_ram()) { + /* Now tell the dest that it should open its end so it can reply */ + qemu_savevm_send_open_return_path(s->file); + + /* And do a ping that will make stuff easier to debug */ + qemu_savevm_send_ping(s->file, 1); + + /* + * Tell the destination that we *might* want to do postcopy later; + * if the other end can't do postcopy it should fail now, nice and + * early. + */ + qemu_savevm_send_postcopy_advise(s->file); + } + + qemu_savevm_state_begin(s->file, &s->params); + + s->setup_time = qemu_clock_get_ms(QEMU_CLOCK_HOST) - setup_start; + current_active_state = MIGRATION_STATUS_ACTIVE; + migrate_set_state(s, MIGRATION_STATUS_SETUP, MIGRATION_STATUS_ACTIVE); + + trace_migration_thread_setup_complete(); + + while (s->state == MIGRATION_STATUS_ACTIVE || + s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE) { + int64_t current_time; + uint64_t pending_size; + + if (!qemu_file_rate_limit(s->file)) { + uint64_t pend_post, pend_nonpost; + + qemu_savevm_state_pending(s->file, max_size, &pend_nonpost, + &pend_post); + pending_size = pend_nonpost + pend_post; + trace_migrate_pending(pending_size, max_size, + pend_post, pend_nonpost); + if (pending_size && pending_size >= max_size) { + /* Still a significant amount to transfer */ + + if (migrate_postcopy_ram() && + s->state != MIGRATION_STATUS_POSTCOPY_ACTIVE && + pend_nonpost <= max_size && + atomic_read(&s->start_postcopy)) { + + if (!postcopy_start(s, &old_vm_running)) { + current_active_state = MIGRATION_STATUS_POSTCOPY_ACTIVE; + entered_postcopy = true; + } + + continue; + } + /* Just another iteration step */ + qemu_savevm_state_iterate(s->file, entered_postcopy); + } else { + trace_migration_thread_low_pending(pending_size); + migration_completion(s, current_active_state, + &old_vm_running, &start_time); + break; + } + } + + if (qemu_file_get_error(s->file)) { + migrate_set_state(s, current_active_state, MIGRATION_STATUS_FAILED); + trace_migration_thread_file_err(); + 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 = (double)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); + } + } + + trace_migration_thread_after_loop(); + /* If we enabled cpu throttling for auto-converge, turn it off. */ + cpu_throttle_stop(); + end_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME); + + qemu_mutex_lock_iothread(); + qemu_savevm_state_cleanup(); + if (s->state == MIGRATION_STATUS_COMPLETED) { + uint64_t transferred_bytes = qemu_ftell(s->file); + s->total_time = end_time - s->total_time; + if (!entered_postcopy) { + 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 && !entered_postcopy) { + vm_start(); + } + } + qemu_bh_schedule(s->cleanup_bh); + qemu_mutex_unlock_iothread(); + + rcu_unregister_thread(); + return NULL; +} + +void migrate_fd_connect(MigrationState *s) +{ + /* 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); + + /* + * Open the return path; currently for postcopy but other things might + * also want it. + */ + if (migrate_postcopy_ram()) { + if (open_return_path_on_source(s)) { + error_report("Unable to open return-path for postcopy"); + migrate_set_state(s, MIGRATION_STATUS_SETUP, + MIGRATION_STATUS_FAILED); + migrate_fd_cleanup(s); + return; + } + } + + migrate_compress_threads_create(); + qemu_thread_create(&s->thread, "migration", migration_thread, s, + QEMU_THREAD_JOINABLE); + s->migration_thread_running = true; +} + +PostcopyState postcopy_state_get(void) +{ + return atomic_mb_read(&incoming_postcopy_state); +} + +/* Set the state and return the old state */ +PostcopyState postcopy_state_set(PostcopyState new_state) +{ + return atomic_xchg(&incoming_postcopy_state, new_state); +} + |
