HP A2Y15AV Manuel D’Utilisation

Datasheet, Volume 2

313

Processor Configuration Registers 

12:8

RO

00010b

Uncore

Supported Adjusted Guest Address Widths (SAGAW) 
This 5-bit field indicates the supported adjusted guest address 

widths (which in turn represents the levels of page-table walks 

for the 4 KB base page size) supported by the hardware 

implementation.
A value of 1 in any of these bits indicates the corresponding 

adjusted guest address width is supported. The adjusted guest 

address widths corresponding to various bit positions within this 

field are:
0 = 30-bit AGAW (2-level page table)
1 = 39-bit AGAW (3-level page table)
2 = 48-bit AGAW (4-level page table)
3 = 57-bit AGAW (5-level page table)
4 = 64-bit AGAW (6-level page table)
Software must ensure that the adjusted guest address width 

used to setup the page tables is one of the supported guest 

address widths reported in this field.

7

RO

0b

Uncore

Caching Mode (CM) 
0 = Not-present and erroneous entries are not cached in any of 

the remapping caches. Invalidations are not required for 

modifications to individual not present or invalid entries. 

However, any modifications that result in decreasing the 

effective permissions or partial permission increases require 

invalidations for them to be effective.

1 = Not-present and erroneous mappings may be cached in the 

remapping caches. Any software updates to the remapping 

structures (including updates to "not-present" or erroneous 

entries) require explicit invalidation.

Hardware implementations of this architecture must support a 

value of 0 in this field.

6

RO

1b

Uncore

Protected High-Memory Region (PHMR) 
0 = Indicates protected high-memory region is not supported.
1 = Indicates protected high-memory region is supported.

5

RO

1b

Uncore

Protected Low-Memory Region (PLMR) 
0 = Protected low-memory region is not supported.
1 = Protected low-memory region is supported.