Processor Configuration Registers
B/D/F/Type:
Address Offset:
Reset Value:
Access:
0/0/0/GFXVTBAR
108–10Fh
0200000000000000h
RO-V, RW, RW-V
64 bits
Size:
BIOS Optimal Default
0000000000000h
Reset
Value
RST/
PWR
Bit
Access
Description
IOTLB Actual Invalidation Granularity (IAIG)
Hardware reports the granularity at which an invalidation request
was processed through this field when reporting invalidation
completion (by clearing the IVT field).
The following are the encodings for this field.
00 = Reserved. This indicates hardware detected an incorrect
invalidation request and ignored the request. Examples of
incorrect invalidation requests include detecting an
unsupported address mask value in Invalidate Address
register for page-selective invalidation requests.
01 = Global Invalidation performed. This could be in response to
a global, domain-selective, or page-selective invalidation
request.
58:57
RO-V
1h
Uncore
10 = Domain-selective invalidation performed using the domain-
id specified by software in the DID field. This could be in
response to a domain-selective or a page-selective
invalidation request.
11 = Domain-page-selective invalidation performed using the
address, mask and hint specified by software in the
Invalidate Address register and domain-id specified in DID
field. This can be in response to a page-selective
invalidation request.
56:50
49
RO
0h
0b
Reserved (RSVD)
Drain Reads (DR)
This field is ignored by hardware if the DRD field is reported as
clear in the Capability register. When the DRD field is reported as
set in the Capability register, the following encodings are
supported for this field:
RW
Uncore
0 = Hardware may complete the IOTLB invalidation without
draining any translated DMA read requests.
1 = Hardware must drain DMA read requests.
Drain Writes (DW)
This field is ignored by hardware if the DWD field is reported as
Clear in the Capability register. When the DWD field is reported
as set in the Capability register, the following encodings are
supported for this field:
0 = Hardware may complete the IOTLB invalidation without
draining DMA write requests.
48
RW
RO
0b
0h
Uncore
1 = Hardware must drain relevant translated DMA write
requests.
47:40
Reserved (RSVD)
Domain-ID (DID)
This field indicates the ID of the domain whose IOTLB entries
need to be selectively invalidated. This field must be
programmed by software for domain-selective and page-selective
invalidation requests.
The Capability register reports the domain-id width supported by
hardware. Software must ensure that the value written to this
field is within this limit. Hardware ignores and not implements
bits 47:(32+N), where N is the supported domain-id width
reported in the Capability register.
39:32
31:0
RW
RO
00h
0h
Uncore
Reserved (RSVD)
292
Datasheet, Volume 2
INTEL [ INTEL ]
