Intel E6320 Specification Update - Page 26

MCi_Status Overflow Bit May Be Incorrectly Set on a Single Instance, LBR, BTS

Page 26 highlights

BJ19. LBR, BTS, BTM May Report a Wrong Address when an Exception/ Interrupt Occurs in 64-bit Mode Problem: An exception/interrupt event should be transparent to the LBR (Last Branch Record), BTS (Branch Trace Store) and BTM (Branch Trace Message) mechanisms. However, during a specific boundary condition where the exception/interrupt occurs right after the execution of an instruction at the lower canonical boundary (0x00007FFFFFFFFFFF) in 64-bit mode, the LBR return registers will save a wrong return address with bits 63 to 48 incorrectly sign extended to all 1's. Subsequent BTS and BTM operations which report the LBR will also be incorrect. Implication: LBR, BTS and BTM may report incorrect information in the event of an exception/ interrupt. Workaround: None identified. Status: For the steppings affected, see the Summary Tables of Changes. BJ20. MCi_Status Overflow Bit May Be Incorrectly Set on a Single Instance of a DTLB Error Problem: A single Data Translation Look Aside Buffer (DTLB) error can incorrectly set the Overflow (bit [62]) in the MCi_Status register. A DTLB error is indicated by MCA error code (bits [15:0]) appearing as binary value, 000x 0000 0001 0100, in the MCi_Status register. Implication: Due to this erratum, the Overflow bit in the MCi_Status register may not be an accurate indication of multiple occurrences of DTLB errors. There is no other impact to normal processor functionality. Workaround: None identified. Status: For the steppings affected, see the Summary Tables of Changes. BJ21. MONITOR or CLFLUSH on the Local XAPIC's Address Space Results in Hang Problem: If the target linear address range for a MONITOR or CLFLUSH is mapped to the local xAPIC's address space, the processor will hang. Implication: When this erratum occurs, the processor will hang. The local xAPIC's address space must be uncached. The MONITOR instruction only functions correctly if the specified linear address range is of the type write-back. CLFLUSH flushes data from the cache. Intel has not observed this erratum with any commercially available software. Workaround: Do not execute MONITOR or CLFLUSH instructions on the local xAPIC address space. Status: For the steppings affected, see the Summary Tables of Changes. 26 Specification Update

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26
Specification Update
BJ19.
LBR, BTS, BTM May Report a Wrong Address when an Exception/
Interrupt Occurs in 64-bit Mode
Problem:
An exception/interrupt event should be transparent to the LBR (Last Branch Record),
BTS (Branch Trace Store) and BTM (Branch Trace Message) mechanisms. However,
during a specific boundary condition where the exception/interrupt occurs right after
the execution of an instruction at the lower canonical boundary (0x00007FFFFFFFFFFF)
in 64-bit mode, the LBR return registers will save a wrong return address with bits 63
to 48 incorrectly sign extended to all 1's. Subsequent BTS and BTM operations which
report the LBR will also be incorrect.
Implication:
LBR, BTS and BTM may report incorrect information in the event of an exception/
interrupt.
Workaround:
None identified.
Status:
For the steppings affected, see the Summary Tables of Changes.
BJ20.
MCi_Status Overflow Bit May Be Incorrectly Set on a Single Instance
of a DTLB Error
Problem:
A single Data Translation Look Aside Buffer (DTLB) error can incorrectly set the
Overflow (bit [62]) in the MCi_Status register. A DTLB error is indicated by MCA error
code (bits [15:0]) appearing as binary value, 000x 0000 0001 0100, in the MCi_Status
register.
Implication:
Due to this erratum, the Overflow bit in the MCi_Status register may not be an accurate
indication of multiple occurrences of DTLB errors. There is no other impact to normal
processor functionality.
Workaround:
None identified.
Status:
For the steppings affected, see the Summary Tables of Changes.
BJ21.
MONITOR or CLFLUSH on the Local XAPIC's Address Space Results in
Hang
Problem:
If the target linear address range for a MONITOR or CLFLUSH is mapped to the local
xAPIC's address space, the processor will hang.
Implication:
When this erratum occurs, the processor will hang. The local xAPIC's address space
must be uncached. The MONITOR instruction only functions correctly if the specified
linear address range is of the type write-back. CLFLUSH flushes data from the cache.
Intel has not observed this erratum with any commercially available software.
Workaround:
Do not execute MONITOR or CLFLUSH instructions on the local xAPIC address space.
Status:
For the steppings affected, see the Summary Tables of Changes.