In one embodiment, a command pertaining to one or more portions of a
register is received from guest software. Further, a determination is
made as to whether the guest software has access to all of the requested
portions of the register based on indicators within a mask field that
correspond to the requested portions of the register. If the guest
software has access to all of the requested portions of the register, the
command received from the guest software is executed on the requested
portions of the register.