Well, seems like it become deprecated for grizzly, but still okay
https://github.com/openstack/nova/blob/stable/grizzly/nova/scheduler/filters/trusted_filter.py
trusted_opts = [
    cfg.StrOpt('attestation_server',
               # deprecated in Grizzly
               deprecated_name='server',
               default=None,
               help='attestation server http'),
    cfg.StrOpt('attestation_server_ca_file',
               deprecated_name='server_ca_file',
               default=None,
               help='attestation server Cert file for Identity verification'),
    cfg.StrOpt('attestation_port',
               deprecated_name='port',
               default='8443',
               help='attestation server port'),
    cfg.StrOpt('attestation_api_url',
               deprecated_name='api_url',
               default='/OpenAttestationWebServices/V1.0',
               help='attestation web API URL'),
    cfg.StrOpt('attestation_auth_blob',
               deprecated_name='auth_blob',
               default=None,
               help='attestation authorization blob - must change'),
    cfg.IntOpt('attestation_auth_timeout',
               default=60,
               help='Attestation status cache valid period length'),
]
we going to change it for compatibility to attestation_*.
Many thanks.