From dankwiki

Model-Specific Registers: per-processor extensions in the x86 family, discoverable via cpuid. Unlike the CPUID registers, many are configurable. MSR's are read and written at the assembly level via the RDMSR and WRMSR instructions. Some MSRs of note include:

  • Accessing the Time Stamp Counter via TSC (0x0000_0010)
  • Managing SYSENTER/SYSEXIT parameters via SEP_{SEL,ESP,EIP} (0x0000_0174, 5 and 6)
  • Managing SYSCALL/SYSRET parameters via STAR (0xC000_0081)
  • Managing the Page Attribute Tables via PAT (0x0000_0277)
  • Managing MTRRs and MCA

See Also