12th Generation Intel® Core™ Processors

Datasheet, Volume 1 of 2

ID 655258
Date 08/08/2022
Document Table of Contents

Remote Action Request

Remote Action Request (RAR) enables a significant speed up of several inter-processor operations by moving such operations from software (OS or application) to hardware.

The main feature is the speedup of TLB shootdowns.

A single RAR operation can invalidate multiple memory pages in the TLB.

A TLB (Translation Lookaside Buffer) is a per-core cache that holds mappings from virtual to physical addresses.

A TLB shootdown is the process of propagating a change in memory mapping (page table entry) to all the cores.

RAR supports the following operations:

  • Page Invalidation: imitates the operation of performing INVLPG instructions corresponding or the TLB invalidation corresponding with “MOV CR3 / CR0”
  • Page Invalidation without CR3 Match: identical to “Page invalidation”, except that the processor does not check for a CR3 match
  • PCID Invalidation: imitates the operation of performing INVPCID instructions
  • EPT Invalidation: imitates the operation of performing INVEPT instructions
  • VPID Invalidation: imitates the operation of performing INVVPID instructions
  • MSR Write: imitates the operation of WRMSR instructions on all cores