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

Table Of Contents
Vol. 3 20-9
VIRTUAL-MACHINE CONTROL STRUCTURES
Manual, Volume 3A). They are used only if the “enable EPT” VM-execution control
is 1.
20.5 HOST-STATE AREA
This section describes fields contained in the host-state area of the VMCS. As noted
earlier, processor state is loaded from these fields on every VM exit (see Section
23.5).
All fields in the host-state area correspond to processor registers:
CR0, CR3, and CR4 (64 bits each; 32 bits on processors that do not support Intel
64 architecture).
RSP and RIP (64 bits each; 32 bits on processors that do not support Intel 64
architecture).
Selector fields (16 bits each) for the segment registers CS, SS, DS, ES, FS, GS,
and TR. There is no field in the host-state area for the LDTR selector.
Base-address fields for FS, GS, TR, GDTR, and IDTR (64 bits each; 32 bits on
processors that do not support Intel 64 architecture).
The following MSRs:
IA32_SYSENTER_CS (32 bits)
IA32_SYSENTER_ESP and IA32_SYSENTER_EIP (64 bits; 32 bits on
processors that do not support Intel 64 architecture).
IA32_PERF_GLOBAL_CTRL (64 bits). This field is supported only on logical
processors that support the 1-setting of the “load IA32_PERF_GLOBAL_CTRL
VM-exit control.
IA32_PAT (64 bits). This field is supported only on logical processors that
support either the 1-setting of the “load IA32_PAT” VM-exit control.
IA32_EFER (64 bits). This field is supported only on logical processors that
support either the 1-setting of the “load IA32_EFER” VM-exit control.
In addition to the state identified here, some processor state components are loaded
with fixed values on every VM exit; there are no fields corresponding to these compo-
nents in the host-state area. See Section 23.5 for details of how state is loaded on
VM exits.
20.6 VM-EXECUTION CONTROL FIELDS
The VM-execution control fields govern VMX non-root operation. These are described
in Section 20.6.1 through Section 20.6.8.