Commit 7e555c6c authored by Dr. David Alan Gilbert's avatar Dr. David Alan Gilbert
Browse files

migration/postcopy: Add max-postcopy-bandwidth parameter 



Limit the background transfer bandwidth during the postcopy
phase to the value set on this new parameter.  The default, 0,
corresponds to the existing behaviour which is unlimited bandwidth.

Signed-off-by: default avatarDr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20180613102642.23995-2-dgilbert@redhat.com>
Reviewed-by: default avatarPeter Xu <peterx@redhat.com>
Signed-off-by: default avatarDr. David Alan Gilbert <dgilbert@redhat.com>
parent b734035b

hmp.c

+7 −0
Original line number Diff line number Diff line
@@ -370,6 +370,9 @@ void hmp_info_migrate_parameters(Monitor *mon, const QDict *qdict) 
        monitor_printf(mon, "%s: %" PRIu64 "\n",

            MigrationParameter_str(MIGRATION_PARAMETER_XBZRLE_CACHE_SIZE),

            params->xbzrle_cache_size);

        monitor_printf(mon, "%s: %" PRIu64 "\n",

            MigrationParameter_str(MIGRATION_PARAMETER_MAX_POSTCOPY_BANDWIDTH),

            params->max_postcopy_bandwidth);

    }



    qapi_free_MigrationParameters(params);
@@ -1676,6 +1679,10 @@ void hmp_migrate_set_parameter(Monitor *mon, const QDict *qdict) 
        }

        p->xbzrle_cache_size = cache_size;

        break;

    case MIGRATION_PARAMETER_MAX_POSTCOPY_BANDWIDTH:

        p->has_max_postcopy_bandwidth = true;

        visit_type_size(v, param, &p->max_postcopy_bandwidth, &err);

        break;

    default:

        assert(0);

    }

migration/migration.c

+34 −1
Original line number Diff line number Diff line
@@ -82,6 +82,11 @@ 
#define DEFAULT_MIGRATE_MULTIFD_CHANNELS 2

#define DEFAULT_MIGRATE_MULTIFD_PAGE_COUNT 16



/* Background transfer rate for postcopy, 0 means unlimited, note

 * that page requests can still exceed this limit.

 */

#define DEFAULT_MIGRATE_MAX_POSTCOPY_BANDWIDTH 0



static NotifierList migration_state_notifiers =

    NOTIFIER_LIST_INITIALIZER(migration_state_notifiers);
@@ -659,6 +664,8 @@ MigrationParameters *qmp_query_migrate_parameters(Error **errp) 
    params->x_multifd_page_count = s->parameters.x_multifd_page_count;

    params->has_xbzrle_cache_size = true;

    params->xbzrle_cache_size = s->parameters.xbzrle_cache_size;

    params->has_max_postcopy_bandwidth = true;

    params->max_postcopy_bandwidth = s->parameters.max_postcopy_bandwidth;



    return params;

}
@@ -1066,6 +1073,9 @@ static void migrate_params_test_apply(MigrateSetParameters *params, 
    if (params->has_xbzrle_cache_size) {

        dest->xbzrle_cache_size = params->xbzrle_cache_size;

    }

    if (params->has_max_postcopy_bandwidth) {

        dest->max_postcopy_bandwidth = params->max_postcopy_bandwidth;

    }

}



static void migrate_params_apply(MigrateSetParameters *params, Error **errp)
@@ -1138,6 +1148,9 @@ static void migrate_params_apply(MigrateSetParameters *params, Error **errp) 
        s->parameters.xbzrle_cache_size = params->xbzrle_cache_size;

        xbzrle_cache_resize(params->xbzrle_cache_size, errp);

    }

    if (params->has_max_postcopy_bandwidth) {

        s->parameters.max_postcopy_bandwidth = params->max_postcopy_bandwidth;

    }

}



void qmp_migrate_set_parameters(MigrateSetParameters *params, Error **errp)
@@ -1887,6 +1900,16 @@ int64_t migrate_xbzrle_cache_size(void) 
    return s->parameters.xbzrle_cache_size;

}



static int64_t migrate_max_postcopy_bandwidth(void)

{

    MigrationState *s;



    s = migrate_get_current();



    return s->parameters.max_postcopy_bandwidth;

}





bool migrate_use_block(void)

{

    MigrationState *s;
@@ -2226,6 +2249,7 @@ static int postcopy_start(MigrationState *ms) 
    QIOChannelBuffer *bioc;

    QEMUFile *fb;

    int64_t time_at_stop = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);

    int64_t bandwidth = migrate_max_postcopy_bandwidth();

    bool restart_block = false;

    int cur_state = MIGRATION_STATUS_ACTIVE;

    if (!migrate_pause_before_switchover()) {
@@ -2280,7 +2304,12 @@ static int postcopy_start(MigrationState *ms) 
     * will notice we're in POSTCOPY_ACTIVE and not actually

     * wrap their state up here

     */

    /* 0 max-postcopy-bandwidth means unlimited */

    if (!bandwidth) {

        qemu_file_set_rate_limit(ms->to_dst_file, INT64_MAX);

    } else {

        qemu_file_set_rate_limit(ms->to_dst_file, bandwidth / XFER_LIMIT_RATIO);

    }

    if (migrate_postcopy_ram()) {

        /* Ping just for debugging, helps line traces up */

        qemu_savevm_send_ping(ms->to_dst_file, 2);
@@ -3042,6 +3071,9 @@ static Property migration_properties[] = { 
    DEFINE_PROP_SIZE("xbzrle-cache-size", MigrationState,

                      parameters.xbzrle_cache_size,

                      DEFAULT_MIGRATE_XBZRLE_CACHE_SIZE),

    DEFINE_PROP_SIZE("max-postcopy-bandwidth", MigrationState,

                      parameters.max_postcopy_bandwidth,

                      DEFAULT_MIGRATE_MAX_POSTCOPY_BANDWIDTH),



    /* Migration capabilities */

    DEFINE_PROP_MIG_CAP("x-xbzrle", MIGRATION_CAPABILITY_XBZRLE),
@@ -3110,6 +3142,7 @@ static void migration_instance_init(Object *obj) 
    params->has_x_multifd_channels = true;

    params->has_x_multifd_page_count = true;

    params->has_xbzrle_cache_size = true;

    params->has_max_postcopy_bandwidth = true;



    qemu_sem_init(&ms->postcopy_pause_sem, 0);

    qemu_sem_init(&ms->postcopy_pause_rp_sem, 0);

qapi/migration.json

+16 −3
Original line number Diff line number Diff line
@@ -517,6 +517,9 @@ 
#                     and a power of 2

#                     (Since 2.11)

#

# @max-postcopy-bandwidth: Background transfer bandwidth during postcopy.

#                     Defaults to 0 (unlimited).  In bytes per second.

#                     (Since 3.0)

# Since: 2.4

##

{ 'enum': 'MigrationParameter',
@@ -525,7 +528,7 @@ 
           'tls-creds', 'tls-hostname', 'max-bandwidth',

           'downtime-limit', 'x-checkpoint-delay', 'block-incremental',

           'x-multifd-channels', 'x-multifd-page-count',

           'xbzrle-cache-size' ] }

           'xbzrle-cache-size', 'max-postcopy-bandwidth' ] }



##

# @MigrateSetParameters:
@@ -593,6 +596,10 @@ 
#                     needs to be a multiple of the target page size

#                     and a power of 2

#                     (Since 2.11)

#

# @max-postcopy-bandwidth: Background transfer bandwidth during postcopy.

#                     Defaults to 0 (unlimited).  In bytes per second.

#                     (Since 3.0)

# Since: 2.4

##

# TODO either fuse back into MigrationParameters, or make
@@ -611,7 +618,8 @@ 
            '*block-incremental': 'bool',

            '*x-multifd-channels': 'int',

            '*x-multifd-page-count': 'int',

            '*xbzrle-cache-size': 'size' } }

            '*xbzrle-cache-size': 'size',

            '*max-postcopy-bandwidth': 'size' } }



##

# @migrate-set-parameters:
@@ -694,6 +702,10 @@ 
#                     needs to be a multiple of the target page size

#                     and a power of 2

#                     (Since 2.11)

#

# @max-postcopy-bandwidth: Background transfer bandwidth during postcopy.

#                     Defaults to 0 (unlimited).  In bytes per second.

#                     (Since 3.0)

# Since: 2.4

##

{ 'struct': 'MigrationParameters',
@@ -710,7 +722,8 @@ 
            '*block-incremental': 'bool' ,

            '*x-multifd-channels': 'uint8',

            '*x-multifd-page-count': 'uint32',

            '*xbzrle-cache-size': 'size' } }

            '*xbzrle-cache-size': 'size',

            '*max-postcopy-bandwidth': 'size'  } }



##

# @query-migrate-parameters: