Errata
30
Specification Update
AA41.
VMLAUNCH/VMRESUME May Not Fail when VMCS is Programmed to
Cause VM Exit to Return to a Different Mode
Problem:
VMLAUNCH/VMRESUME instructions may not fail if the value of the “host
address-space size” VM-exit control differs from the setting of
IA32_EFER.LMA.
Implication:
Programming the VMCS to allow the monitor to be in different modes prior to
VMLAUNCH/VMRESUME and after VM-exit may result in undefined behavior.
Workaround:
Software should ensure that "host address-space size" VM-exit control has
the same value as IA32_EFER.LMA at the time of VMLAUNCH/VMRESUME.
Status:
For the steppings affected, see the
Summary Tables of Changes.
AA42.
A Continuous Loop Executing Bus Lock Transactions on One Logical
Processor may Prevent Another Logical Processor from Acquiring
Resources
Problem:
In a system supporting Hyper-Threading Technology, when one hardware
thread is in a continuous loop executing bus locks plus other traffic, the other
hardware thread may be prevented from acquiring resources to also execute
a lock.
Implication:
This erratum may cause system hang or unpredictable system behavior. This
erratum has not been observed with commercially available software.
Workaround:
None identified.
Status:
For the steppings affected, see the
Summary Tables of Changes
.
AA43.
An Unexpected Memory Access May be Issued During Execution of
the WRMSR Instruction Under Certain Conditions
Problem:
The processor may generate an unexpected memory access during the
WRMSR instruction under certain conditions.
Implication:
When this erratum occurs, an unexpected read may be issued on FSB.
Subsequent side effects are dependent on platform operation and may
include a system hang. This erratum has not been observed on any
commercial operating system.
Workaround:
It is possible for BIOS to contain a workaround for this erratum.
Status:
For the steppings affected, see the
Summary Tables of Changes
.
AA44.
Combining Some Processors With Intel 945® Chipsets Can Lead to
Unpredictable System Behavior
Problem:
Some processors with 800 MHz Front Side Bus (FSB), when used in
combination with a motherboard based on the Intel 945® chipset, may
observe FSB bit errors which may result in unpredictable system behavior.
