diff --git a/migration/migration-hmp-cmds.c b/migration/migration-hmp-cmds.c index 5b25ba24f7..d206700a43 100644 --- a/migration/migration-hmp-cmds.c +++ b/migration/migration-hmp-cmds.c @@ -321,6 +321,10 @@ void hmp_info_migrate_parameters(Monitor *mon, const QDict *qdict) monitor_printf(mon, "%s: %" PRIu64 " bytes/second\n", MigrationParameter_str(MIGRATION_PARAMETER_MAX_BANDWIDTH), params->max_bandwidth); + assert(params->has_avail_switchover_bandwidth); + monitor_printf(mon, "%s: %" PRIu64 " bytes/second\n", + MigrationParameter_str(MIGRATION_PARAMETER_AVAIL_SWITCHOVER_BANDWIDTH), + params->avail_switchover_bandwidth); assert(params->has_downtime_limit); monitor_printf(mon, "%s: %" PRIu64 " ms\n", MigrationParameter_str(MIGRATION_PARAMETER_DOWNTIME_LIMIT), @@ -574,6 +578,16 @@ void hmp_migrate_set_parameter(Monitor *mon, const QDict *qdict) } p->max_bandwidth = valuebw; break; + case MIGRATION_PARAMETER_AVAIL_SWITCHOVER_BANDWIDTH: + p->has_avail_switchover_bandwidth = true; + ret = qemu_strtosz_MiB(valuestr, NULL, &valuebw); + if (ret < 0 || valuebw > INT64_MAX + || (size_t)valuebw != valuebw) { + error_setg(&err, "Invalid size %s", valuestr); + break; + } + p->avail_switchover_bandwidth = valuebw; + break; case MIGRATION_PARAMETER_DOWNTIME_LIMIT: p->has_downtime_limit = true; visit_type_size(v, param, &p->downtime_limit, &err); diff --git a/migration/migration.c b/migration/migration.c index 0e1002d017..ed04ca3b1c 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -2710,17 +2710,33 @@ static void migration_update_counters(MigrationState *s, { uint64_t transferred, transferred_pages, time_spent; uint64_t current_bytes; /* bytes transferred since the beginning */ + uint64_t switchover_bw; + /* Expected bandwidth when switching over to destination QEMU */ + double expected_bw_per_ms; double bandwidth; if (current_time < s->iteration_start_time + BUFFER_DELAY) { return; } + switchover_bw = migrate_avail_switchover_bandwidth(); current_bytes = migration_transferred_bytes(s->to_dst_file); transferred = current_bytes - s->iteration_initial_bytes; time_spent = current_time - s->iteration_start_time; bandwidth = (double)transferred / time_spent; - s->threshold_size = bandwidth * migrate_downtime_limit(); + + if (switchover_bw) { + /* + * If the user specified a switchover bandwidth, let's trust the + * user so that can be more accurate than what we estimated. + */ + expected_bw_per_ms = switchover_bw / 1000; + } else { + /* If the user doesn't specify bandwidth, we use the estimated */ + expected_bw_per_ms = bandwidth; + } + + s->threshold_size = expected_bw_per_ms * migrate_downtime_limit(); s->mbps = (((double) transferred * 8.0) / ((double) time_spent / 1000.0)) / 1000.0 / 1000.0; @@ -2737,7 +2753,7 @@ static void migration_update_counters(MigrationState *s, if (stat64_get(&mig_stats.dirty_pages_rate) && transferred > 10000) { s->expected_downtime = - stat64_get(&mig_stats.dirty_bytes_last_sync) / bandwidth; + stat64_get(&mig_stats.dirty_bytes_last_sync) / expected_bw_per_ms; } migration_rate_reset(s->to_dst_file); @@ -2745,7 +2761,9 @@ static void migration_update_counters(MigrationState *s, update_iteration_initial_status(s); trace_migrate_transferred(transferred, time_spent, - bandwidth, s->threshold_size); + /* Both in unit bytes/ms */ + bandwidth, switchover_bw / 1000, + s->threshold_size); } static bool migration_can_switchover(MigrationState *s) diff --git a/migration/migration.h b/migration/migration.h index cd5534337c..974897a8d0 100644 --- a/migration/migration.h +++ b/migration/migration.h @@ -294,7 +294,7 @@ struct MigrationState { /* * The final stage happens when the remaining data is smaller than * this threshold; it's calculated from the requested downtime and - * measured bandwidth + * measured bandwidth, or avail-switchover-bandwidth if specified. */ int64_t threshold_size; diff --git a/migration/options.c b/migration/options.c index 6bbfd4853d..546cbe3106 100644 --- a/migration/options.c +++ b/migration/options.c @@ -125,6 +125,8 @@ Property migration_properties[] = { parameters.cpu_throttle_tailslow, false), DEFINE_PROP_SIZE("x-max-bandwidth", MigrationState, parameters.max_bandwidth, MAX_THROTTLE), + DEFINE_PROP_SIZE("avail-switchover-bandwidth", MigrationState, + parameters.avail_switchover_bandwidth, 0), DEFINE_PROP_UINT64("x-downtime-limit", MigrationState, parameters.downtime_limit, DEFAULT_MIGRATE_SET_DOWNTIME), @@ -780,6 +782,13 @@ uint64_t migrate_max_bandwidth(void) return s->parameters.max_bandwidth; } +uint64_t migrate_avail_switchover_bandwidth(void) +{ + MigrationState *s = migrate_get_current(); + + return s->parameters.avail_switchover_bandwidth; +} + uint64_t migrate_max_postcopy_bandwidth(void) { MigrationState *s = migrate_get_current(); @@ -917,6 +926,8 @@ MigrationParameters *qmp_query_migrate_parameters(Error **errp) s->parameters.tls_authz : ""); params->has_max_bandwidth = true; params->max_bandwidth = s->parameters.max_bandwidth; + params->has_avail_switchover_bandwidth = true; + params->avail_switchover_bandwidth = s->parameters.avail_switchover_bandwidth; params->has_downtime_limit = true; params->downtime_limit = s->parameters.downtime_limit; params->has_x_checkpoint_delay = true; @@ -1056,6 +1067,15 @@ bool migrate_params_check(MigrationParameters *params, Error **errp) return false; } + if (params->has_avail_switchover_bandwidth && + (params->avail_switchover_bandwidth > SIZE_MAX)) { + error_setg(errp, QERR_INVALID_PARAMETER_VALUE, + "avail_switchover_bandwidth", + "an integer in the range of 0 to "stringify(SIZE_MAX) + " bytes/second"); + return false; + } + if (params->has_downtime_limit && (params->downtime_limit > MAX_MIGRATE_DOWNTIME)) { error_setg(errp, QERR_INVALID_PARAMETER_VALUE, @@ -1225,6 +1245,10 @@ static void migrate_params_test_apply(MigrateSetParameters *params, dest->max_bandwidth = params->max_bandwidth; } + if (params->has_avail_switchover_bandwidth) { + dest->avail_switchover_bandwidth = params->avail_switchover_bandwidth; + } + if (params->has_downtime_limit) { dest->downtime_limit = params->downtime_limit; } @@ -1341,6 +1365,10 @@ static void migrate_params_apply(MigrateSetParameters *params, Error **errp) } } + if (params->has_avail_switchover_bandwidth) { + s->parameters.avail_switchover_bandwidth = params->avail_switchover_bandwidth; + } + if (params->has_downtime_limit) { s->parameters.downtime_limit = params->downtime_limit; } diff --git a/migration/options.h b/migration/options.h index 045e2a41a2..93ee938ab8 100644 --- a/migration/options.h +++ b/migration/options.h @@ -80,6 +80,7 @@ int migrate_decompress_threads(void); uint64_t migrate_downtime_limit(void); uint8_t migrate_max_cpu_throttle(void); uint64_t migrate_max_bandwidth(void); +uint64_t migrate_avail_switchover_bandwidth(void); uint64_t migrate_max_postcopy_bandwidth(void); int migrate_multifd_channels(void); MultiFDCompression migrate_multifd_compression(void); diff --git a/migration/trace-events b/migration/trace-events index ee9c8f4d63..d8c2aa846d 100644 --- a/migration/trace-events +++ b/migration/trace-events @@ -186,7 +186,7 @@ source_return_path_thread_shut(uint32_t val) "0x%x" source_return_path_thread_resume_ack(uint32_t v) "%"PRIu32 source_return_path_thread_switchover_acked(void) "" migration_thread_low_pending(uint64_t pending) "%" PRIu64 -migrate_transferred(uint64_t transferred, uint64_t time_spent, uint64_t bandwidth, uint64_t size) "transferred %" PRIu64 " time_spent %" PRIu64 " bandwidth %" PRIu64 " max_size %" PRId64 +migrate_transferred(uint64_t transferred, uint64_t time_spent, uint64_t bandwidth, uint64_t avail_bw, uint64_t size) "transferred %" PRIu64 " time_spent %" PRIu64 " bandwidth %" PRIu64 " switchover_bw %" PRIu64 " max_size %" PRId64 process_incoming_migration_co_end(int ret, int ps) "ret=%d postcopy-state=%d" process_incoming_migration_co_postcopy_end_main(void) "" postcopy_preempt_enabled(bool value) "%d" diff --git a/qapi/migration.json b/qapi/migration.json index d7dfaa5db9..360e609f66 100644 --- a/qapi/migration.json +++ b/qapi/migration.json @@ -758,6 +758,16 @@ # @max-bandwidth: to set maximum speed for migration. maximum speed # in bytes per second. (Since 2.8) # +# @avail-switchover-bandwidth: to set the available bandwidth that +# migration can use during switchover phase. NOTE! This does not +# limit the bandwidth during switchover, but only for calculations when +# making decisions to switchover. By default, this value is zero, +# which means QEMU will estimate the bandwidth automatically. This can +# be set when the estimated value is not accurate, while the user is +# able to guarantee such bandwidth is available when switching over. +# When specified correctly, this can make the switchover decision much +# more accurate. (Since 8.2) +# # @downtime-limit: set maximum tolerated downtime for migration. # maximum downtime in milliseconds (Since 2.8) # @@ -839,7 +849,7 @@ 'cpu-throttle-initial', 'cpu-throttle-increment', 'cpu-throttle-tailslow', 'tls-creds', 'tls-hostname', 'tls-authz', 'max-bandwidth', - 'downtime-limit', + 'avail-switchover-bandwidth', 'downtime-limit', { 'name': 'x-checkpoint-delay', 'features': [ 'unstable' ] }, 'block-incremental', 'multifd-channels', @@ -924,6 +934,16 @@ # @max-bandwidth: to set maximum speed for migration. maximum speed # in bytes per second. (Since 2.8) # +# @avail-switchover-bandwidth: to set the available bandwidth that +# migration can use during switchover phase. NOTE! This does not +# limit the bandwidth during switchover, but only for calculations when +# making decisions to switchover. By default, this value is zero, +# which means QEMU will estimate the bandwidth automatically. This can +# be set when the estimated value is not accurate, while the user is +# able to guarantee such bandwidth is available when switching over. +# When specified correctly, this can make the switchover decision much +# more accurate. (Since 8.2) +# # @downtime-limit: set maximum tolerated downtime for migration. # maximum downtime in milliseconds (Since 2.8) # @@ -1017,6 +1037,7 @@ '*tls-hostname': 'StrOrNull', '*tls-authz': 'StrOrNull', '*max-bandwidth': 'size', + '*avail-switchover-bandwidth': 'size', '*downtime-limit': 'uint64', '*x-checkpoint-delay': { 'type': 'uint32', 'features': [ 'unstable' ] }, @@ -1127,6 +1148,16 @@ # @max-bandwidth: to set maximum speed for migration. maximum speed # in bytes per second. (Since 2.8) # +# @avail-switchover-bandwidth: to set the available bandwidth that +# migration can use during switchover phase. NOTE! This does not +# limit the bandwidth during switchover, but only for calculations when +# making decisions to switchover. By default, this value is zero, +# which means QEMU will estimate the bandwidth automatically. This can +# be set when the estimated value is not accurate, while the user is +# able to guarantee such bandwidth is available when switching over. +# When specified correctly, this can make the switchover decision much +# more accurate. (Since 8.2) +# # @downtime-limit: set maximum tolerated downtime for migration. # maximum downtime in milliseconds (Since 2.8) # @@ -1217,6 +1248,7 @@ '*tls-hostname': 'str', '*tls-authz': 'str', '*max-bandwidth': 'size', + '*avail-switchover-bandwidth': 'size', '*downtime-limit': 'uint64', '*x-checkpoint-delay': { 'type': 'uint32', 'features': [ 'unstable' ] },