diff options
| author | Kevin Tian <kevin.tian@intel.com> | 2026-08-05 07:43:07 +0800 |
|---|---|---|
| committer | Joerg Roedel <joerg.roedel@amd.com> | 2026-08-10 10:04:07 +0200 |
| commit | 1c677d8a2c3cbc22287ac34483e6b2b7b20ddf52 (patch) | |
| tree | 0282cc5a0964f8235a35c8ee4c9d79814f626b75 /include/linux | |
| parent | 3f29c94ecac0708d096f770cdedc5e075912b9e0 (diff) | |
iommu/vt-d: Support the new DMA_REMAP_OPT_OUT flag bit
Some BIOS already provides config options to expose/hide VT-d units
as a whole to/from system software. A new demand is to allow exposing
VT-d units but requesting system software to disable DMA remapping
while sustaining interrupt remapping. This can be communicated now by
setting the new DMA_REMAP_OPT_OUT flag bit in the DMAR table, as
introduced in VT-d spec v5.2 (section 8.1, DMA Remapping Reporting
Structure).
Introduce a new off policy (DMAR_FW_OFF) for DMA_REMAP_OPT_OUT. As
the strongest off policy, it cannot be overridden by user opts or
any force_on types. If tboot is enabled in the meantime, kernel will
panic. It is user responsibility to configure BIOS properly.
One cleanup is left for future - the DMAR flag is parsed multiple
times, in detect_intel_iommu(), dmar_platform_optin() (which can be
called at run-time), etc. Caching it is a cleaner way.
Signed-off-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/dmar.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/dmar.h b/include/linux/dmar.h index 692b2b445761..63e35df2cef4 100644 --- a/include/linux/dmar.h +++ b/include/linux/dmar.h @@ -24,6 +24,7 @@ struct acpi_dmar_header; #define DMAR_INTR_REMAP 0x1 #define DMAR_X2APIC_OPT_OUT 0x2 #define DMAR_PLATFORM_OPT_IN 0x4 +#define DMAR_REMAP_OPT_OUT 0x8 struct intel_iommu; |