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

Table Of Contents
Vol. 3 22-5
VM ENTRIES
Any clearing of the bytes occurs even if the VM entry subsequently fails.
If the “use TPR shadow” VM-execution control is 1, bits 31:4 of the TPR threshold
VM-execution control field must be 0.
The following check is performed if the “use TPR shadow” VM-execution control is
1 and the “virtualize APIC accesses” VM-execution control is 0: the value of
bits 3:0 of the TPR threshold VM-execution control field should not be greater
than the value of bits 7:4 in byte 80H on the virtual-APIC page (see Section
20.6.8).
If the “NMI exiting” VM-execution control is 0, the “virtual NMIs” VM-execution
control must be 0.
If the “virtual NMIs” VM-execution control is 0, the “NMI-window exiting” VM-
execution control must be 0.
If the “virtualize APIC-accesses” VM-execution control is 1, the APIC-access
address must satisfy the following checks:
Bits 11:0 of the address must be 0.
On processors that support Intel 64 architecture, the address should not set
any bits beyond the processor's physical-address width.
On processors that support the IA-32 architecture, the address should not set
any bits in the range 63:32.
If the “virtualize x2APIC mode” VM-execution control is 1, the “use TPR shadow”
VM-execution control must be 1 and the “virtualize APIC accesses” VM-execution
control must be 0.
1
If the “enable VPID” VM-execution control is 1, the value of the VPID VM-
execution control field must not be 0000H.
If the “enable EPT” VM-execution control is 1, the EPTP VM-execution control field
(see Table 20-8 in Section 20.6.11) must satisfy the following checks:
2
The EPT memory type (bits 2:0) must be a value supported by the logical
processor as indicated in the IA32_VMX_EPT_VPID_CAP MSR (see Appendix
G.10).
Bits 5:3 (1 less than the EPT page-walk length) must be 3, indicating an EPT
page-walk length of 4; see Section 24.2.2.
Reserved bits 11:6 and 63:N (where N is the processor’s physical-address
width) must all be 0.
1. Note that “virtualize APIC accesses” and “virtualize x2APIC mode” are both secondary processor-
based VM-execution controls. If bit 31 of the primary processor-based VM-execution controls is
0, VM entry functions as if both theses controls were 0. See Section 20.6.2.
2. Note that “enable EPT” is a secondary processor-based VM-execution control. If bit 31 of the pri-
mary processor-based VM-execution controls is 0, VM entry functions as if the “enable EPT” VM-
execution control were 0. See Section 20.6.2.