docs: def _get_vcpu_field_and_address(self, field_name, x, y, p):
          """Get the field and address for a VCPU struct field."""
          vcpu_struct = self.structs[b"vcpu"]
          field = vcpu_struct[six.b(field_name)]
          address = (self.read_struct_field("sv", "vcpu_base", x, y) +
                     vcpu_struct.size * p) + field.offset
          pack_chars = b"<" + field.pack_chars
          return field, address, pack_chars