Contents

Virtual Machine Control Structure (VMCS) Field IDs

Fields you can read or change using the Hypervisor framework’s read and write functions.

Overview

You can examine the state of, or control the operation of the framework and indivudal guests through various fields in the Virtual Machine Control Structure. The VMCS fields listed below describe which fields are read-only or read-write using the Hypervisor framework’s read and write functions.

Readable and Writable VMCS Guest Fields

These are fields, states, flags, and registers in hypervisor guests that you can read from or write to. In some instances there are limitations on what you can read or write, such as specific regsters or bit positions as indicated for each field.

  • RIP, RSP, RFLAGS

  • CR3, CR4, DR7

  • PDTR — {0, 1, 2, 3}

  • CR3-Target — {0, 1, 2, 3}

  • IA32_SYSENTER_CS

  • IA32_SYSENTER_ESP

  • IA32_SYSENTER_EIP

  • IA32_EFER

  • Interruptibility State

  • Pending Debug Exceptions

  • Selector — {ES, CS, SS, DS, FS, GS, LDTR, TR}

  • Base — {ES, CS, SS, DS, FS, GS, LDTR, TR, GDTR, ITDR}

  • Limit — {ES, CS, SS, DS, FS, GS, LDTR, TR, GDTR, ITDR}

  • Access Rights — {ES, CS, SS, FS, GS, LDTR, TR}.

Readable and Writable VMCS Control Fields

These control fields that you can both read and write.

  • Exception Bitmap

  • Framework

  • Hypervisor

  • Page-Fault Error-Code Mask

  • VM-Entry Interruption-Information Field

  • VM-Entry Exception Error Code

  • VM-Entry Instruction Length

  • TPR Threshold

  • PLE Gap

  • PLE Window

  • CR0 Guest/Host Mask

  • CR4 Guest/Host Mask

  • CR0 Read Shadow

  • CR4 Read Shadow

Readable and Conditionally Writable VMCS Guest Fields

These guest fields describe the guest’s control registers and activity state. Updating these field requires the conditions listed for each field:

  • CR0 — CR0.CD and CR0.NW are unset

  • Activity State — The current state must be either ACTIVE or HLT

Readable and Conditionally Writable VMCS Control Fields

These fields describe VM execution controls, and access to the framework’s guest/host mask. Reading or updating these field requires the conditions listed for each field:

Read-Only VMCS Control Fields

These read-only fields provide information about time-stamp counter offsets and programmable interrupt controllers addresses:

  • TCS Offset

  • APIC-Access Address

Read-Only VMCS Data Fields

These read-only fields describe error and exit information, interrupt descriptor tables, or guest address information:

  • VM-Instruction Error

  • Exit Reason

  • VM-Exit Interruption Information

  • VM-Exit Interruption Error Code

  • IDT-Vectoring Information Field

  • IDT-Vectoring Error Code

  • VM-Exit Instruction Length

  • VM-Exit Instruction Information

  • Guest-Physical Address

  • Exit Qualification

  • Guest-Linear Address

Topics

Enumerations

See Also

Field management