Intel E5345 Specification Update - Page 41

The Stack Size May be Incorrect as a Result of VIP/VIF Check

Page 41 highlights

AJ92. EFLAGS, CR0, CR4 and the EXF4 Signal May be Incorrect after Shutdown Problem: When the processor is going into shutdown due to an RSM inconsistency failure, EFLAGS, CR0 and CR4 may be incorrect. In addition the EXF4 signal may still be asserted. This may be observed if the processor is taken out of shutdown by NMI# Implication: A processor that has been taken out of shutdown may have an incorrect EFLAGS, CR0 and CR4. In addition the EXF4 signal may still be asserted. Workaround: None identified. Status: For the steppings affected, see the Summary Tables of Changes. AJ93. Performance Monitoring Counter MACRO_INSTS.DECODED May Not Count Some Decoded Instructions Problem: MACRO_INSTS.DECODED performance monitoring counter (Event 0AAH, Umask 01H) counts the number of macro instructions decoded, but not necessarily retired. The event is undercounted when the decoded instructions are a complete loop iteration that is decoded in one cycle and the loop is streamed by the LSD (Loop Stream Detector), as described in the Optimizing the Front End section of the Intel® 64 and IA-32 Architectures Optimization Reference Manual. Implication: The count value returned by the performance monitoring counter MACRO_INST.DECODED may be lower than expected. The degree of undercounting is dependent on the occurrence of loop iterations that are decoded in one cycle and whether the loop is streamed by the LSD while the counter is active. Workaround: Workaround: None identified. Status: For the steppings affected, see the Summary Tables of Changes. AJ94. The Stack Size May be Incorrect as a Result of VIP/VIF Check on SYSEXIT and SYSRET Problem: The stack size may be incorrect under the following scenario: · The stack size was changed due to a SYSEXIT or SYSRET · PVI (Protected Mode Virtual Interrupts) mode was enabled (CR4.PVI == 1) · Both the VIF (Virtual Interrupt Flag) and VIP (Virtual Interrupt Pending) flags of the EFLAGS register are set Implication: If this erratum occurs the stack size may be incorrect, consequently this may result in unpredictable system behavior. Intel has not observed this erratum with any commercially available software. Workaround: None Identified. Status: For the steppings affected, see the Summary Tables of Changes. AJ95. Performance Monitoring Event SIMD_UOP_TYPE_EXEC.MUL is Counted Incorrectly for PMULUDQ Instruction Problem: Performance Monitoring Event SIMD_UOP_TYPE_EXEC.MUL (Event select 0B3H, Umask 01H) counts the number of SIMD packed multiply micro-ops executed. The count for PMULUDQ micro-ops may be lower than expected. No other instruction is affected. Implication: The count value returned by the performance monitoring event SIMD_UOP_TYPE_EXEC.MUL may be lower than expected. The degree of undercount depends on actual occurrences of PMULUDQ instructions, while the counter is active. Workaround: None identified. Status: For the steppings affected, see the Summary Tables of Changes. AJ96. Problem: Storage of PEBS Record Delayed Following Execution of MOV SS or STI When a performance monitoring counter is configured for PEBS (Precise Event Based Sampling), overflow of the counter results in storage of a PEBS record in the PEBS Intel® Xeon® Processor 5300 Series 41 Specification Update, December 2010

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Intel® Xeon® Processor 5300 Series
41
Specification Update, December 2010
AJ92.
EFLAGS, CR0, CR4 and the EXF4 Signal May be Incorrect after
Shutdown
Problem:
When the processor is going into shutdown due to an RSM inconsistency failure,
EFLAGS, CR0 and CR4 may be incorrect. In addition the EXF4 signal may still be
asserted. This may be observed if the processor is taken out of shutdown by NMI#
Implication:
A processor that has been taken out of shutdown may have an incorrect EFLAGS, CR0
and CR4. In addition the EXF4 signal may still be asserted.
Workaround:
None identified.
Status:
For the steppings affected, see the Summary Tables of Changes.
AJ93.
Performance Monitoring Counter MACRO_INSTS.DECODED May Not
Count Some Decoded Instructions
Problem:
MACRO_INSTS.DECODED performance monitoring counter (Event 0AAH, Umask 01H)
counts the number of macro instructions decoded, but not necessarily retired.
The
event is undercounted when the decoded instructions are a complete loop iteration that
is decoded in one cycle and the loop is streamed by the LSD (Loop Stream Detector),
as described in the Optimizing the Front End section of the Intel® 64 and IA-32
Architectures Optimization Reference Manual.
Implication:
The count value returned by the performance monitoring counter
MACRO_INST.DECODED may be lower than expected.
The degree of undercounting is
dependent on the occurrence of loop iterations that are decoded in one cycle and
whether the loop is streamed by the LSD while the counter is active.
Workaround:
Workaround: None identified.
Status:
For the steppings affected, see the Summary Tables of Changes.
AJ94.
The Stack Size May be Incorrect as a Result of VIP/VIF Check on
SYSEXIT and SYSRET
Problem:
The stack size may be incorrect under the following scenario:
·
The stack size was changed due to a SYSEXIT or SYSRET
·
PVI (Protected Mode Virtual Interrupts) mode was enabled (CR4.PVI == 1)
·
Both the VIF (Virtual Interrupt Flag) and VIP (Virtual Interrupt Pending) flags of
the EFLAGS register are set
Implication:
If this erratum occurs the stack size may be incorrect, consequently this may result in
unpredictable system behavior. Intel has not observed this erratum with any
commercially available software.
Workaround:
None Identified.
Status:
For the steppings affected, see the
Summary Tables of Changes
.
AJ95.
Performance Monitoring Event SIMD_UOP_TYPE_EXEC.MUL is
Counted Incorrectly for PMULUDQ Instruction
Problem:
Performance Monitoring Event SIMD_UOP_TYPE_EXEC.MUL (Event select 0B3H, Umask
01H) counts the number of SIMD packed multiply micro-ops executed. The count for
PMULUDQ micro-ops may be lower than expected. No other instruction is affected.
Implication:
The
count
value
returned
by
the
performance
monitoring
event
SIMD_UOP_TYPE_EXEC.MUL may be lower than expected.
The degree of undercount
depends on actual occurrences of PMULUDQ instructions, while the counter is active.
Workaround:
None identified.
Status:
For the steppings affected, see the
Summary Tables of Changes
.
AJ96.
Storage of PEBS Record Delayed Following Execution of MOV SS or STI
Problem:
When a performance monitoring counter is configured for PEBS (Precise Event Based
Sampling), overflow of the counter results in storage of a PEBS record in the PEBS