diff options
Diffstat (limited to 'qemu/migration/migration.c')
| -rw-r--r-- | qemu/migration/migration.c | 1016 |
1 files changed, 889 insertions, 127 deletions
diff --git a/qemu/migration/migration.c b/qemu/migration/migration.c index 4ddb9adce..991313a86 100644 --- a/qemu/migration/migration.c +++ b/qemu/migration/migration.c @@ -13,7 +13,8 @@ * GNU GPL, version 2 or (at your option) any later version. */ -#include "qemu-common.h" +#include "qemu/osdep.h" +#include "qemu/cutils.h" #include "qemu/error-report.h" #include "qemu/main-loop.h" #include "migration/migration.h" @@ -21,16 +22,20 @@ #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/util.h" #include "qapi-event.h" +#include "qom/cpu.h" +#include "exec/memory.h" +#include "exec/address-spaces.h" -#define MAX_THROTTLE (32 << 20) /* Migration speed throttling */ +#define MAX_THROTTLE (32 << 20) /* Migration transfer speed throttling */ /* Amount of time to allocate to each "chunk" of bandwidth-throttled * data. */ @@ -44,6 +49,9 @@ #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) @@ -53,6 +61,13 @@ static NotifierList 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 */ @@ -60,6 +75,7 @@ static bool deferred_incoming; /* For outgoing */ MigrationState *migrate_get_current(void) { + static bool once; static MigrationState current_migration = { .state = MIGRATION_STATUS_NONE, .bandwidth_limit = MAX_THROTTLE, @@ -71,8 +87,16 @@ MigrationState *migrate_get_current(void) 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; } @@ -86,15 +110,19 @@ MigrationIncomingState *migration_incoming_get_current(void) MigrationIncomingState *migration_incoming_state_new(QEMUFile* f) { - mis_current = g_malloc0(sizeof(MigrationIncomingState)); - mis_current->file = f; + mis_current = g_new0(MigrationIncomingState, 1); + mis_current->from_src_file = f; + mis_current->state = MIGRATION_STATUS_NONE; 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; @@ -176,7 +204,7 @@ static int global_state_post_load(void *opaque, int version_id) s->received = true; trace_migrate_global_state_post_load(runstate); - r = qapi_enum_parse(RunState_lookup, runstate, RUN_STATE_MAX, + r = qapi_enum_parse(RunState_lookup, runstate, RUN_STATE__MAX, -1, &local_err); if (r == -1) { @@ -240,6 +268,35 @@ static void deferred_incoming_migration(Error **errp) 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; @@ -266,37 +323,27 @@ void qemu_start_incoming_migration(const char *uri, Error **errp) } } -static void process_incoming_migration_co(void *opaque) +static void process_incoming_migration_bh(void *opaque) { - QEMUFile *f = opaque; Error *local_err = NULL; - int ret; - - migration_incoming_state_new(f); - migrate_generate_event(MIGRATION_STATUS_ACTIVE); - ret = qemu_loadvm_state(f); - - 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); - } - migrate_generate_event(MIGRATION_STATUS_COMPLETED); - qemu_announce_self(); + MigrationIncomingState *mis = opaque; /* Make sure all file formats flush their mutable metadata */ bdrv_invalidate_cache_all(&local_err); if (local_err) { + migrate_set_state(&mis->state, MIGRATION_STATUS_ACTIVE, + 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. */ @@ -312,6 +359,64 @@ static void process_incoming_migration_co(void *opaque) 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_set_state(&mis->state, MIGRATION_STATUS_ACTIVE, + MIGRATION_STATUS_COMPLETED); + qemu_bh_delete(mis->bh); + migration_incoming_state_destroy(); +} + +static void process_incoming_migration_co(void *opaque) +{ + QEMUFile *f = opaque; + MigrationIncomingState *mis; + PostcopyState ps; + int ret; + + mis = migration_incoming_state_new(f); + postcopy_state_set(POSTCOPY_INCOMING_NONE); + migrate_set_state(&mis->state, MIGRATION_STATUS_NONE, + 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(); + + if (ret < 0) { + migrate_set_state(&mis->state, MIGRATION_STATUS_ACTIVE, + MIGRATION_STATUS_FAILED); + error_report("load of migration failed: %s", strerror(-ret)); + migrate_decompress_threads_join(); + exit(EXIT_FAILURE); + } + + mis->bh = qemu_bh_new(process_incoming_migration_bh, mis); + qemu_bh_schedule(mis->bh); } void process_incoming_migration(QEMUFile *f) @@ -325,6 +430,50 @@ void process_incoming_migration(QEMUFile *f) 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 @@ -344,7 +493,7 @@ MigrationCapabilityStatusList *qmp_query_migrate_capabilities(Error **errp) int i; caps = NULL; /* silence compiler warning */ - for (i = 0; i < MIGRATION_CAPABILITY_MAX; i++) { + for (i = 0; i < MIGRATION_CAPABILITY__MAX; i++) { if (head == NULL) { head = g_malloc0(sizeof(*caps)); caps = head; @@ -372,10 +521,32 @@ MigrationParameters *qmp_query_migrate_parameters(Error **errp) 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()) { @@ -435,6 +606,45 @@ MigrationInfo *qmp_query_migrate(Error **errp) 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; + 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 MIGRATION_STATUS_COMPLETED: @@ -478,8 +688,7 @@ void qmp_migrate_set_capabilities(MigrationCapabilityStatusList *params, MigrationState *s = migrate_get_current(); MigrationCapabilityStatusList *cap; - if (s->state == MIGRATION_STATUS_ACTIVE || - s->state == MIGRATION_STATUS_SETUP) { + if (migration_is_setup_or_active(s->state)) { error_setg(errp, QERR_MIGRATION_ACTIVE); return; } @@ -487,6 +696,20 @@ void qmp_migrate_set_capabilities(MigrationCapabilityStatusList *params, 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_POSTCOPY_RAM] = + false; + } + } } void qmp_migrate_set_parameters(bool has_compress_level, @@ -494,7 +717,11 @@ void qmp_migrate_set_parameters(bool has_compress_level, bool has_compress_threads, int64_t compress_threads, bool has_decompress_threads, - int64_t decompress_threads, Error **errp) + 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(); @@ -517,6 +744,18 @@ void qmp_migrate_set_parameters(bool has_compress_level, "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; @@ -528,13 +767,44 @@ void qmp_migrate_set_parameters(bool has_compress_level, 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) +void migrate_set_state(int *state, int old_state, int new_state) { - if (atomic_cmpxchg(&s->state, old_state, new_state) == old_state) { + if (atomic_cmpxchg(state, old_state, new_state) == old_state) { trace_migrate_set_state(new_state); migrate_generate_event(new_state); } @@ -547,21 +817,27 @@ static void migrate_fd_cleanup(void *opaque) qemu_bh_delete(s->cleanup_bh); s->cleanup_bh = NULL; - if (s->file) { + flush_page_queue(s); + + if (s->to_dst_file) { trace_migrate_fd_cleanup(); qemu_mutex_unlock_iothread(); - qemu_thread_join(&s->thread); + 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; + qemu_fclose(s->to_dst_file); + s->to_dst_file = NULL; } - assert(s->state != MIGRATION_STATUS_ACTIVE); + 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, + migrate_set_state(&s->state, MIGRATION_STATUS_CANCELLING, MIGRATION_STATUS_CANCELLED); } @@ -571,24 +847,29 @@ static void migrate_fd_cleanup(void *opaque) void migrate_fd_error(MigrationState *s) { trace_migrate_fd_error(); - assert(s->file == NULL); - migrate_set_state(s, MIGRATION_STATUS_SETUP, MIGRATION_STATUS_FAILED); + assert(s->to_dst_file == NULL); + migrate_set_state(&s->state, 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; + QEMUFile *f = migrate_get_current()->to_dst_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 (old_state != MIGRATION_STATUS_SETUP && - old_state != MIGRATION_STATUS_ACTIVE) { + if (!migration_is_setup_or_active(old_state)) { break; } - migrate_set_state(s, old_state, MIGRATION_STATUS_CANCELLING); + migrate_set_state(&s->state, old_state, MIGRATION_STATUS_CANCELLING); } while (s->state != MIGRATION_STATUS_CANCELLING); /* @@ -629,34 +910,48 @@ bool migration_has_failed(MigrationState *s) s->state == MIGRATION_STATUS_FAILED); } -static MigrationState *migrate_init(const MigrationParams *params) +bool migration_in_postcopy(MigrationState *s) { - 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; - int compress_level = s->parameters[MIGRATION_PARAMETER_COMPRESS_LEVEL]; - int compress_thread_count = - s->parameters[MIGRATION_PARAMETER_COMPRESS_THREADS]; - int decompress_thread_count = - s->parameters[MIGRATION_PARAMETER_DECOMPRESS_THREADS]; + return (s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE); +} - memcpy(enabled_capabilities, s->enabled_capabilities, - sizeof(enabled_capabilities)); +bool migration_in_postcopy_after_devices(MigrationState *s) +{ + return migration_in_postcopy(s) && s->postcopy_after_devices; +} - memset(s, 0, sizeof(*s)); +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->to_dst_file = NULL; + s->state = MIGRATION_STATUS_NONE; s->params = *params; - memcpy(s->enabled_capabilities, enabled_capabilities, - sizeof(enabled_capabilities)); - s->xbzrle_cache_size = xbzrle_cache_size; - - s->parameters[MIGRATION_PARAMETER_COMPRESS_LEVEL] = compress_level; - s->parameters[MIGRATION_PARAMETER_COMPRESS_THREADS] = - compress_thread_count; - s->parameters[MIGRATION_PARAMETER_DECOMPRESS_THREADS] = - decompress_thread_count; - s->bandwidth_limit = bandwidth_limit; - migrate_set_state(s, MIGRATION_STATUS_NONE, MIGRATION_STATUS_SETUP); + 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->postcopy_after_devices = false; + s->migration_thread_running = false; + s->last_req_rb = NULL; + + migrate_set_state(&s->state, MIGRATION_STATUS_NONE, MIGRATION_STATUS_SETUP); + + QSIMPLEQ_INIT(&s->src_page_requests); s->total_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME); return s; @@ -709,8 +1004,7 @@ void qmp_migrate(const char *uri, bool has_blk, bool blk, params.blk = has_blk && blk; params.shared = has_inc && inc; - if (s->state == MIGRATION_STATUS_ACTIVE || - s->state == MIGRATION_STATUS_SETUP || + if (migration_is_setup_or_active(s->state) || s->state == MIGRATION_STATUS_CANCELLING) { error_setg(errp, QERR_MIGRATION_ACTIVE); return; @@ -729,12 +1023,6 @@ void qmp_migrate(const char *uri, bool has_blk, bool blk, 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)) { @@ -754,7 +1042,8 @@ void qmp_migrate(const char *uri, bool has_blk, bool blk, } else { error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "uri", "a valid migration protocol"); - migrate_set_state(s, MIGRATION_STATUS_SETUP, MIGRATION_STATUS_FAILED); + migrate_set_state(&s->state, MIGRATION_STATUS_SETUP, + MIGRATION_STATUS_FAILED); return; } @@ -817,8 +1106,9 @@ void qmp_migrate_set_speed(int64_t value, Error **errp) s = migrate_get_current(); s->bandwidth_limit = value; - if (s->file) { - qemu_file_set_rate_limit(s->file, s->bandwidth_limit / XFER_LIMIT_RATIO); + if (s->to_dst_file) { + qemu_file_set_rate_limit(s->to_dst_file, + s->bandwidth_limit / XFER_LIMIT_RATIO); } } @@ -829,6 +1119,15 @@ void qmp_migrate_set_downtime(double value, Error **errp) max_downtime = (uint64_t)value; } +bool migrate_postcopy_ram(void) +{ + MigrationState *s; + + s = migrate_get_current(); + + return s->enabled_capabilities[MIGRATION_CAPABILITY_POSTCOPY_RAM]; +} + bool migrate_auto_converge(void) { MigrationState *s; @@ -911,10 +1210,419 @@ int64_t migrate_xbzrle_cache_size(void) } /* 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; + uint8_t buf[512]; + 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 > sizeof(buf)) { + 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->to_dst_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->to_dst_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->state, 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; + } + + ret = bdrv_inactivate_all(); + if (ret < 0) { + goto fail; + } + + /* + * Cause any non-postcopiable, but iterative devices to + * send out their final data. + */ + qemu_savevm_state_complete_precopy(ms->to_dst_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->to_dst_file, INT64_MAX); + /* Ping just for debugging, helps line traces up */ + qemu_savevm_send_ping(ms->to_dst_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->to_dst_file, qsb)) { + goto fail_closefb; + } + qemu_fclose(fb); + + /* Send a notify to give a chance for anything that needs to happen + * at the transition to postcopy and after the device state; in particular + * spice needs to trigger a transition now + */ + ms->postcopy_after_devices = true; + notifier_list_notify(&migration_state_notifiers, ms); + + 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->to_dst_file, 4); + + ret = qemu_file_get_error(ms->to_dst_file); + if (ret) { + error_report("postcopy_start: Migration stream errored"); + migrate_set_state(&ms->state, MIGRATION_STATUS_POSTCOPY_ACTIVE, + MIGRATION_STATUS_FAILED); + } + + return ret; + +fail_closefb: + qemu_fclose(fb); +fail: + migrate_set_state(&ms->state, 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) { + ret = bdrv_inactivate_all(); + } + if (ret >= 0) { + qemu_file_set_rate_limit(s->to_dst_file, INT64_MAX); + qemu_savevm_state_complete_precopy(s->to_dst_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->to_dst_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->to_dst_file)) { + trace_migration_completion_file_err(); + goto fail; + } + + migrate_set_state(&s->state, current_active_state, + MIGRATION_STATUS_COMPLETED); + return; + +fail: + migrate_set_state(&s->state, 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; @@ -922,70 +1630,92 @@ static void *migration_thread(void *opaque) 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); - qemu_savevm_state_begin(s->file, &s->params); + qemu_savevm_state_header(s->to_dst_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->to_dst_file); + + /* And do a ping that will make stuff easier to debug */ + qemu_savevm_send_ping(s->to_dst_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->to_dst_file); + } + + qemu_savevm_state_begin(s->to_dst_file, &s->params); s->setup_time = qemu_clock_get_ms(QEMU_CLOCK_HOST) - setup_start; - migrate_set_state(s, MIGRATION_STATUS_SETUP, MIGRATION_STATUS_ACTIVE); + current_active_state = MIGRATION_STATUS_ACTIVE; + migrate_set_state(&s->state, MIGRATION_STATUS_SETUP, + MIGRATION_STATUS_ACTIVE); + + trace_migration_thread_setup_complete(); - while (s->state == MIGRATION_STATUS_ACTIVE) { + 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)) { - pending_size = qemu_savevm_state_pending(s->file, max_size); - trace_migrate_pending(pending_size, max_size); + if (!qemu_file_rate_limit(s->to_dst_file)) { + uint64_t pend_post, pend_nonpost; + + qemu_savevm_state_pending(s->to_dst_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) { - 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 = 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(s->file); - } - } - qemu_mutex_unlock_iothread(); + /* Still a significant amount to transfer */ - if (ret < 0) { - migrate_set_state(s, MIGRATION_STATUS_ACTIVE, - MIGRATION_STATUS_FAILED); - break; - } + if (migrate_postcopy_ram() && + s->state != MIGRATION_STATUS_POSTCOPY_ACTIVE && + pend_nonpost <= max_size && + atomic_read(&s->start_postcopy)) { - if (!qemu_file_get_error(s->file)) { - migrate_set_state(s, MIGRATION_STATUS_ACTIVE, - MIGRATION_STATUS_COMPLETED); - break; + 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->to_dst_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, MIGRATION_STATUS_ACTIVE, + if (qemu_file_get_error(s->to_dst_file)) { + migrate_set_state(&s->state, 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 transferred_bytes = qemu_ftell(s->to_dst_file) - + initial_bytes; uint64_t time_spent = current_time - initial_time; - double bandwidth = transferred_bytes / time_spent; + 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; + s->mbps = (((double) transferred_bytes * 8.0) / + ((double) time_spent / 1000.0)) / 1000.0 / 1000.0; trace_migrate_transferred(transferred_bytes, time_spent, bandwidth, max_size); @@ -995,31 +1725,36 @@ static void *migration_thread(void *opaque) s->expected_downtime = s->dirty_bytes_rate / bandwidth; } - qemu_file_reset_rate_limit(s->file); + qemu_file_reset_rate_limit(s->to_dst_file); initial_time = current_time; - initial_bytes = qemu_ftell(s->file); + initial_bytes = qemu_ftell(s->to_dst_file); } - if (qemu_file_rate_limit(s->file)) { + if (qemu_file_rate_limit(s->to_dst_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_cancel(); + qemu_savevm_state_cleanup(); if (s->state == MIGRATION_STATUS_COMPLETED) { - uint64_t transferred_bytes = qemu_ftell(s->file); + uint64_t transferred_bytes = qemu_ftell(s->to_dst_file); s->total_time = end_time - s->total_time; - s->downtime = end_time - start_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) { + if (old_vm_running && !entered_postcopy) { vm_start(); } } @@ -1036,13 +1771,40 @@ void migrate_fd_connect(MigrationState *s) s->expected_downtime = max_downtime/1000000; s->cleanup_bh = qemu_bh_new(migrate_fd_cleanup, s); - qemu_file_set_rate_limit(s->file, + qemu_file_set_rate_limit(s->to_dst_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->state, 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); +} + |