Intel E7-8891 v2 CM8063601377422 Benutzerhandbuch

404

Intel

®

 Xeon

® 

Processor E7-2800/4800/8800 v2 Product Family

Datasheet Volume Two: Functional Description, February 2014

Intel

®

VT-d Global Command.

31:31

RW

0x0

translation_enable:

Software writes to this field to request hardware to enable/disable DMA-

remapping hardware.0: Disable DMA-remapping hardware
1: Enable DMA-remapping hardware
Hardware reports the status of the translation enable operation through the 

TES field in the Global Status register. Before enabling (or reenabling) DMA-

remapping hardware through this field, software must:
- Setup the DMA-remapping structures in memory
- Flush the write buffers (through WBF field), if write buffer flushing is 

reported as required.
- Set the root-entry table pointer in hardware (through SRTP field).
- Perform global invalidation of the context-cache and global invalidation of 

IOTLB
- If advanced fault logging supported, setup fault log pointer (through SFL 

field) and enable advanced fault logging (through EAFL field).
There may be active DMA requests in the platform when software updates 

this field. Hardware must enable or disable remapping logic only at 

deterministic transaction boundaries, so that any in-flight transaction is 

either subject to remapping or not at all. 

30:30

RW_V

0x0

set_root_table_pointer:

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 register.Hardware reports the status of the root table pointer 

set operation through the RTPS field in the Global Status register. The root 

table pointer set operation must be performed before enabling or reenabling 

(after disabling) DMA remapping hardware.
After a root table pointer set operation, software must globally invalidate the 

context cache followed by global invalidate of IOTLB. This is required to 

ensure hardware uses only the remapping structures referenced by the new 

root table pointer, and not any 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.
Clearing this bit has no effect.

29:29

RO

0x0

set_fault_log_pointer:

N/A to processor.

28:28

RO

0x0

enable_advanced_fault_logging:

N/A to processor.

27:27

RO

0x0

write_buffer_flush:

N/A to processor.