5.4. TLB match process

The Virtualization Extensions and the Security Extensions provide for multiple virtual address spaces that are translated differently. The main TLB entries store all the required context information to facilitate a match and avoid the need for a TLB flush on a context or virtual machine switch. Each TLB entry contains a virtual address, page size, physical address, and a set of memory properties that include the memory type and access permissions. Each entry is marked as being associated with a particular Application Space ID (ASID), or as global for all application spaces. The TLB entry also contains a field to store the Virtual Machine Identifier (VMID) that brought in the entry, applicable to accesses made from the non-secure state, as defined by the Virtualization extensions. There is also a bit that records whether that TLB entry is allocated on a Hyp mode request. A TLB entry match occurs when the following conditions are met:


  • For a request originating from Hyp mode, the ASID and VMID match are ignored.

  • For a request originating from Secure state, the VMID match is ignored.

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