Intel CORE 2 DUO E7000 - SPECIFICATION UPDATE 7-2010 Specification page 38

AW55. A VM Exit Due to a Fault While Delivering a Software Interrupt May
Save Incorrect Data into the VMCS
If a fault occurs during delivery of a software interrupt (INTn) in virtual-8086
Problem:
mode when virtual mode extensions are in effect and that fault causes a VM
exit, incorrect data may be saved into the VMCS. Specifically, information
about the software interrupt may not be reported in the IDT-vectoring
information field. In addition, the interruptibility-state field may indicate
blocking by STI or by MOV SS if such blocking were in effect before execution
of the INTn instruction or before execution of the VM-entry instruction that
injected the software interrupt.
Implication: In general, VMM software that follows the guidelines given in the section
"Handling VM Exits Due to Exceptions" of Intel® 64 and IA-32 Architectures
Software Developer's Manual Volume 3B: System Programming Guide should
not be affected. If the erratum improperly causes indication of blocking by
STI or by MOV SS, the ability of a VMM to inject an interrupt may be delayed
by one instruction.
Workaround: VMM software should follow the guidelines given in the section "Handling VM
Exits Due to Exceptions" of Intel® 64 and IA-32 Architectures Software
Developer's Manual Volume 3B: System Programming Guide.
For the steppings affected, see the Summary Tables of Changes.
Status:
AW56. A VM Exit Occuring in IA-32e Mode May Not Produce a VMX Abort
When Expected
If a VM exit occurs while the processor is in IA-32e mode and the "host
Problem:
address-space size" VM-exit control is 0, a VMX abort should occur. Due to
this erratum, the expected VMX aborts may not occur and instead the VM Exit
will occur normally. The conditions required to observe this erratum are a VM
entry that returns from SMM with the "IA-32e guest" VM-entry control set to
1 in the SMM VMCS and the "host address-space size" VM-exit control cleared
to 0 in the executive VMCS.
Implication: A VM Exit will occur when a VMX Abort was expected.
Workaround: An SMM VMM should always set the "IA-32e guest" VM-entry control in the
SMM VMCS to be the value that was in the LMA bit (IA32_EFER.LMA.LMA[bit
10]) in the IA32_EFER MSR (C0000080H) at the time of the last SMM VM
exit. If this guideline is followed, that value will be 1 only if the "host
address-space size" VM-exit control is 1 in the executive VMCS.
For the steppings affected, see the Summary Tables of Changes.
Status:
AW57. IRET under Certain Conditions May Cause an Unexpected Alignment
Check Exception
In IA-32e mode, it is possible to get an Alignment Check Exception (#AC) on
Problem:
the IRET instruction even though alignment checks were disabled at the start
of the IRET. This can only occur if the IRET instruction is returning from CPL3
38
Errata
® ™
Intel Core 2 Duo Processor
Specification Update