Function tdx_guest::tdcall::read_servetd

pub fn read_servetd(
    binding_handle: u64,
    field_identifier: u64,
    uuid: [u64; 4],
) -> Result<(u64, u64, [u64; 4]), TdCallError>

As a service TD, read a metadata field (control structure field) of a target TD.

Inputs:

• binding_handle: the binding handle of the target TD.
• field_identifier: the identifier of the field to read. The LAST_ELEMENT_IN_FIELD and LAST_FIELD_IN_SEQUENCE components of the field identifier must be 0. WRITE_MASK_VALID, INC_SIZE, CONTEXT_CODE and ELEMENT_SIZE_CODE components of the field identifier are ignored. A value of -1 is a special case: it is not a valid field identifier; in this case the first readable field identifier is returned in RDX.
• uuid: the TD_UUID of the target TD, using little-Endian.

Outputs:

• Next readable field identifier. A value of -1 indicates no next field identifier is available. If the input field identifier was -1, RDX returns the first readable field identifier. In case of another error, RDX returns -1.
• Contents of the field. In case of an error, as indicated by RAX, R8 returns 0.
• Updated target TD’s TD_UUID, using little-Endian.