- CR4_VMXE: VMX operations, used for hardware virtualization.
- CR4_SMXE: SMX operations, used for safer Mode Extensions (ground for
Intel's TXT - Trusted Execution Technology - platform).
- CR4_FSGSBASE: enable *FSBASE and *GSBASE instructions, for R/W access
to FS/GS segment base addresses.
- CR4_PCIDE: enable Process Context IDentifiers (other architectures may call
these "address space identifiers").
- CR4_OSXSAVE: enable xsave and xrestore instructions
- CR4_SMEP: Supervisor Mode Execution Prevention. Allows enforcing --x rights
from cpl 0.
From Intel® 64 and IA-32 Architectures Software Developer’s Manual,
March 2012.
Align declarations.
CPUID_* bits for these features follow.