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

Table Of Contents
Vol. 3 22-33
VM ENTRIES
there are not also other errors. Different processors may give different
exit qualifications for the same VMCS.
VM-entry failure due to MSR loading. The exit qualification is loaded to
indicate which entry in the VM-entry MSR-load area caused the problem
(1 for the first entry, 2 for the second, etc.).
All other VM-exit information fields are unmodified.
2. Processor state is loaded as would be done on a VM exit (see Section 23.5). If
this results in [CR4.PAE & CR0.PG & ~IA32_EFER.LMA] = 1, page-directory-
pointer-table entries (PDPTES) may be checked and loaded (see Section 23.5.4).
3. The state of blocking by NMI is what it was before VM entry.
4. MSRs are loaded as specified in the VM-exit MSR-load area (see Section 23.6).
Although this process resembles that of a VM exit, many steps taken during a VM exit
do not occur for these VM-entry failures:
Most VM-exit information fields are not updated (see step 1 above).
The valid bit in the VM-entry interruption-information field is not cleared.
The guest-state area is not modified.
No MSRs are saved into the VM-exit MSR-store area.
22.8 MACHINE CHECKS DURING VM ENTRY
If a machine check occurs during a VM entry, one of the following occurs:
The machine check is handled normally:
If CR4.MCE = 1, a machine-check exception (#MC) is delivered through the
IDT.
If CR4.MCE = 0, operation of the logical processor depends on whether the
logical processor is in SMX operation:
1
If the logical processor is in SMX operation, an Intel
®
TXT shutdown
condition occurs. The error code used is 000CH, indicating “unrecoverable
machine check condition.” See Intel
®
Trusted Execution Technology
Preliminary Architecture Specification.
If the logical processor is outside SMX operation, it goes to the shutdown
state.
1. A logical processor is in SMX operation if GETSEC[SEXIT] has not been executed since the last
execution of GETSEC[SENTER]. A logical processor is outside SMX operation if GETSEC[SENTER]
has not been executed or if GETSEC[SEXIT] was executed after the last execution of GET-
SEC[SENTER]. See Chapter 6, “Safer Mode Extensions Reference,” in Intel® 64 and IA-32 Archi-
tectures Software Developer’s Manual, Volume 2B.