Linux v6.6.1 - intel
# SPDX-License-Identifier: GPL-2.0-only
# Intel IOMMU support
config DMAR_TABLE
bool
config DMAR_PERF
bool
config DMAR_DEBUG
bool
config INTEL_IOMMU
bool "Support for Intel IOMMU using DMA Remapping Devices"
depends on PCI_MSI && ACPI && (X86 || IA64)
select DMA_OPS
select IOMMU_API
select IOMMU_IOVA
select NEED_DMA_MAP_STATE
select DMAR_TABLE
select SWIOTLB
select PCI_ATS
select PCI_PRI
select PCI_PASID
help
DMA remapping (DMAR) devices support enables independent address
translations for Direct Memory Access (DMA) from devices.
These DMA remapping devices are reported via ACPI tables
and include PCI device scope covered by these DMA
remapping devices.
if INTEL_IOMMU
config INTEL_IOMMU_DEBUGFS
bool "Export Intel IOMMU internals in Debugfs"
depends on IOMMU_DEBUGFS
select DMAR_PERF
select DMAR_DEBUG
help
!!!WARNING!!!
DO NOT ENABLE THIS OPTION UNLESS YOU REALLY KNOW WHAT YOU ARE DOING!!!
Expose Intel IOMMU internals in Debugfs.
This option is -NOT- intended for production environments, and should
only be enabled for debugging Intel IOMMU.
config INTEL_IOMMU_SVM
bool "Support for Shared Virtual Memory with Intel IOMMU"
depends on X86_64
select MMU_NOTIFIER
select IOMMU_SVA
help
Shared Virtual Memory (SVM) provides a facility for devices
to access DMA resources through process address space by
means of a Process Address Space ID (PASID).
config INTEL_IOMMU_DEFAULT_ON
bool "Enable Intel DMA Remapping Devices by default"
default y
help
Selecting this option will enable a DMAR device at boot time if
one is found. If this option is not selected, DMAR support can
be enabled by passing intel_iommu=on to the kernel.
config INTEL_IOMMU_BROKEN_GFX_WA
bool "Workaround broken graphics drivers (going away soon)"
depends on BROKEN && X86
help
Current Graphics drivers tend to use physical address
for DMA and avoid using DMA APIs. Setting this config
option permits the IOMMU driver to set a unity map for
all the OS-visible memory. Hence the driver can continue
to use physical addresses for DMA, at least until this
option is removed in the 2.6.32 kernel.
config INTEL_IOMMU_FLOPPY_WA
def_bool y
depends on X86
help
Floppy disk drivers are known to bypass DMA API calls
thereby failing to work when IOMMU is enabled. This
workaround will setup a 1:1 mapping for the first
16MiB to make floppy (an ISA device) work.
config INTEL_IOMMU_SCALABLE_MODE_DEFAULT_ON
bool "Enable Intel IOMMU scalable mode by default"
default y
help
Selecting this option will enable by default the scalable mode if
hardware presents the capability. The scalable mode is defined in
VT-d 3.0. The scalable mode capability could be checked by reading
/sys/devices/virtual/iommu/dmar*/intel-iommu/ecap. If this option
is not selected, scalable mode support could also be enabled by
passing intel_iommu=sm_on to the kernel. If not sure, please use
the default value.
config INTEL_IOMMU_PERF_EVENTS
def_bool y
bool "Intel IOMMU performance events"
depends on INTEL_IOMMU && PERF_EVENTS
help
Selecting this option will enable the performance monitoring
infrastructure in the Intel IOMMU. It collects information about
key events occurring during operation of the remapping hardware,
to aid performance tuning and debug. These are available on modern
processors which support Intel VT-d 4.0 and later.
endif # INTEL_IOMMU