Intel 64 and IA-32 Architectures Software Developers Manual Volume 3B, System Programming Guide Part 2

Table Of Contents
20-22 Vol. 3
VIRTUAL-MACHINE CONTROL STRUCTURES
20.8 VM-ENTRY CONTROL FIELDS
The VM-entry control fields govern the behavior of VM entries. They are discussed in
Sections 20.8.1 through 20.8.3.
20.8.1 VM-Entry Controls
The VM-entry controls constitute a 32-bit vector that governs the basic operation of
VM entries. Table 20-11 lists the controls supported. See Chapter 22 for how these
controls affect VM entries.
Table 20-11. Definitions of VM-Entry Controls
Bit Position(s) Name Description
2 Load debug
controls
This control determines whether DR7 and the
IA32_DEBUGCTL MSR are loaded on VM exit.
Note that the first processors to support the virtual-machine
extensions supported only the 1-setting of this control.
9 IA-32e mode guest On processors that support Intel 64 architecture, this control
determines whether the logical processor is in IA-32e mode
after VM entry. Its value is loaded into IA32_EFER.LMA and
IA32_EFER.LME as part of VM entry.
1
This control must be 0 on processors that do not support
Intel 64 architecture.
NOTES:
1. Since Intel 64 architecture specifies that IA32_EFER.LMA is always set to the logical-AND of
CR0.PG and IA32_EFER.LME, and since CR0.PG is always 1 in VMX operation; IA32_EFER.LMA is
always identical to IA32_EFER.LME in VMX operation.
10 Entry to SMM This control determines whether the logical processor is in
system-management mode (SMM) after VM entry. This
control must be 0 for any VM entry from outside SMM.
11 Deactivate dual-
monitor treatment
If set to 1, the default treatment of SMIs and SMM is in effect
after the VM entry (see Section 25.15.7). This control must
be 0 for any VM entry from outside SMM.
13 Load
IA32_PERF_GLOBA
L_CTRL
This control determines whether the
IA32_PERF_GLOBAL_CTRL MSR is loaded on VM entry.
14 Load IA32_PAT This control determines whether the IA32_PAT MSR is loaded
on VM entry.
15 Load IA32_EFER This control determines whether the IA32_EFER MSR is
loaded on VM entry.