Vol. 3D B-9

FIELD ENCODING IN VMCS

B.4.2  

Natural-Width Read-Only Data Fields

A value of 1 in bits 11:10 of an encoding indicates a read-only data field. These fields are distinguished by their 
index value in bits 9:1. Table B-13 enumerates the natural-width read-only data fields.

B.4.3  

Natural-Width Guest-State Fields

A value of 2 in bits 11:10 of an encoding indicates a field in the guest-state area. These fields are distinguished by 
their index value in bits 9:1. Table B-14 enumerates the natural-width guest-state fields.

The base-address fields for ES, CS, SS, and DS in the guest-state area are defined to be natural-width (with 64 bits 
on processors supporting Intel 64 architecture) even though these fields are only 32-bits wide in the Intel 64 archi-
tecture. VM entry ensures that the high 32 bits of these fields are cleared to 0.

Table B-13.  Encodings for Natural-Width Read-Only Data Fields (0110_01xx_xxxx_xxx0B)

Field Name

Index

Encoding

Exit qualification

000000000B

00006400H

I/O RCX

000000001B

00006402H

I/O RSI

000000010B

00006404H

I/O RDI

000000011B

00006406H

I/O RIP

000000100B

00006408H

Guest-linear address

000000101B

0000640AH

Table B-14.  Encodings for Natural-Width Guest-State Fields (0110_10xx_xxxx_xxx0B) 

Field Name

Index

Encoding

Guest CR0

000000000B

00006800H

Guest CR3

000000001B

00006802H

Guest CR4

000000010B

00006804H

Guest ES base

000000011B

00006806H

Guest CS base

000000100B

00006808H

Guest SS base

000000101B

0000680AH

Guest DS base

000000110B

0000680CH

Guest FS base

000000111B

0000680EH

Guest GS base

000001000B

00006810H

Guest LDTR base

000001001B

00006812H

Guest TR base

000001010B

00006814H

Guest GDTR base

000001011B

00006816H

Guest IDTR base

000001100B

00006818H

Guest DR7

000001101B

0000681AH

Guest RSP

000001110B

0000681CH

Guest RIP

000001111B

0000681EH

Guest RFLAGS

000010000B

00006820H

Guest pending debug exceptions

000010001B

00006822H

Guest IA32_SYSENTER_ESP

000010010B

00006824H

Guest IA32_SYSENTER_EIP

000010011B

00006826H