Datasheet

Processor Configuration Registers
340 Datasheet, Volume 2
2.21.28 IVA_REG—Invalidate Address Register
This register provides the DMA address whose corresponding IOTLB entry needs to be
invalidated through the corresponding IOTLB Invalidate register. This register is a
write-only register.
B/D/F/Type: 0/0/0/VC0PREMAP
Address Offset: 100–107h
Reset Value: 0000000000000000h
Access: RW
Size: 64 bits
BIOS Optimal Default 00000000h
Bit Access
Reset
Value
RST/
PWR
Description
63:39 RO 0h Reserved (RSVD)
38:12 RW 0000000h Uncore
Address (ADDR)
Software provides the DMA address that needs to be page-
selectively invalidated. To make a page-selective invalidation
request to hardware, software must first write the appropriate
fields in this register, and then issue the appropriate page-
selective invalidate command through the IOTLB_REG. Hardware
ignores bits 63: N, where N is the maximum guest address width
(MGAW) supported.
11:7 RO 0h Reserved (RSVD)
6RW 0hUncore
Invalidation Hint (IH)
The field provides hint to hardware about preserving or flushing
the non-leaf (page-directory) entries that may be cached in
hardware:
0 = Software may have modified both leaf and non-leaf page-
table entries corresponding to mappings specified in the
ADDR and AM fields. On a page-selective invalidation
request, hardware must flush both the cached leaf and non-
leaf page-table entries corresponding to the mappings
specified by ADDR and AM fields.
1 = Software has not modified any non-leaf page-table entries
corresponding to mappings specified in the ADDR and AM
fields. On a page-selective invalidation request, hardware
may preserve the cached non-leaf page-table entries
corresponding to mappings specified by ADDR and AM fields.
5:0 RW 00h Uncore
Address Mask (AM)
The value in this field specifies the number of low-order bits of
the ADDR field that must be masked for the invalidation
operation. This field enables software to request invalidation of
contiguous mappings for size-aligned regions. For example:
Mask ADDR bits Pages
Value masked invalidated
0None 1
112 2
2 13:12 4
3 14:12 8
4 15:12 16
When invalidating mappings for super-pages, software must
specify the appropriate mask value. For example, when
invalidating mapping for a 2 MB page, software must specify an
address mask value of at least 9.
Hardware implementations report the maximum supported mask
value through the Capability register.