Processor Configuration Registers
B/D/F/Type:
Address Offset:
Reset Value:
Access:
0/0/0/GFXVTBAR
18–1Bh
00000000h
RO, WO
32 bits
Size:
BIOS Optimal Default
000000h
Reset
Value
RST/
PWR
Bit
Access
Description
Set Root Table Pointer (SRTP)
Software sets this field to set/update the root-entry table pointer
used by hardware. The root-entry table pointer is specified
through the Root-entry Table Address (RTA_REG) register.
Hardware reports the status of the "Set Root Table Pointer"
operation through the RTPS field in the Global Status register.
The "Set Root Table Pointer" operation must be performed before
enabling or re-enabling (after disabling) DMA remapping through
the TE field.
After a "Set Root Table Pointer" operation, software must globally
invalidate the context cache and then globally invalidate of
IOTLB. This is required to ensure hardware uses only the
remapping structures referenced by the new root table pointer,
and not stale cached entries. While DMA remapping hardware is
active, software may update the root table pointer through this
field. However, to ensure valid in-flight DMA requests are
deterministically remapped, software must ensure that the
structures referenced by the new root table pointer are
programmed to provide the same remapping results as the
structures referenced by the previous root-table pointer.
30
WO
0b
Uncore
Clearing this bit has no effect. The value returned on read of this
field is undefined.
Set Fault Log (SFL)
This field is valid only for implementations supporting advanced
fault logging.
Software sets this field to request hardware to set/update the
fault-log pointer used by hardware. The fault-log pointer is
specified through Advanced Fault Log register.
Hardware reports the status of the 'Set Fault Log' operation
through the FLS field in the Global Status register.
29
RO
0b
Uncore
The fault log pointer must be set before enabling advanced fault
logging (through EAFL field). Once advanced fault logging is
enabled, the fault log pointer may be updated through this field
while DMA remapping is active.
Clearing this bit has no effect. The value returned on read of this
field is undefined.
Enable Advanced Fault Logging (EAFL)
This field is valid only for implementations supporting advanced
fault logging.
Software writes to this field to request hardware to enable or
disable advanced fault logging:
0 = Disable advanced fault logging. In this case, translation
faults are reported through the Fault Recording registers.
28
RO
0b
Uncore
1 = Enable use of memory-resident fault log. When enabled,
translation faults are recorded in the memory-resident log.
The fault log pointer must be set in hardware (through the
SFL field) before enabling advanced fault logging. Hardware
reports the status of the advanced fault logging enable
operation through the AFLS field in the Global Status
register.
The value returned on read of this field is undefined.
268
Datasheet, Volume 2
INTEL [ INTEL ]
