The scope of hyperthreading instructions is not covered in this book. Refer to the Intel-specific documentation for full specifications. They are considered OS/System instructions and as such will not be discussed in this book. They are accessible by the application layer at the low privilege level but are not part of the general application development process. They are only referenced here for informational purposes.
Windows Assembly Language and Systems Programming: 16- and 32-Bit Low-Level Programming for the PC and Windows