linux/drivers/vfio/Kconfig
Jason Gunthorpe 2a3dab19a0 vfio-iommufd: Allow iommufd to be used in place of a container fd
This makes VFIO_GROUP_SET_CONTAINER accept both a vfio container FD and an
iommufd.

In iommufd mode an IOAS will exist after the SET_CONTAINER, but it will
not be attached to any groups.

For VFIO this means that the VFIO_GROUP_GET_STATUS and
VFIO_GROUP_FLAGS_VIABLE works subtly differently. With the container FD
the iommu_group_claim_dma_owner() is done during SET_CONTAINER but for
IOMMUFD this is done during VFIO_GROUP_GET_DEVICE_FD. Meaning that
VFIO_GROUP_FLAGS_VIABLE could be set but GET_DEVICE_FD will fail due to
viability.

As GET_DEVICE_FD can fail for many reasons already this is not expected to
be a meaningful difference.

Reorganize the tests for if the group has an assigned container or iommu
into a vfio_group_has_iommu() function and consolidate all the duplicated
WARN_ON's etc related to this.

Call container functions only if a container is actually present on the
group.

Link: https://lore.kernel.org/r/5-v4-42cd2eb0e3eb+335a-vfio_iommufd_jgg@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Tested-by: Alex Williamson <alex.williamson@redhat.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Yi Liu <yi.l.liu@intel.com>
Tested-by: Lixiao Yang <lixiao.yang@intel.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Tested-by: Yu He <yu.he@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2022-12-02 11:52:03 -04:00

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# SPDX-License-Identifier: GPL-2.0-only
menuconfig VFIO
tristate "VFIO Non-Privileged userspace driver framework"
select IOMMU_API
depends on IOMMUFD || !IOMMUFD
select VFIO_IOMMU_TYPE1 if MMU && (X86 || S390 || ARM || ARM64)
select INTERVAL_TREE
help
VFIO provides a framework for secure userspace device drivers.
See Documentation/driver-api/vfio.rst for more details.
If you don't know what to do here, say N.
if VFIO
config VFIO_IOMMU_TYPE1
tristate
default n
config VFIO_IOMMU_SPAPR_TCE
tristate
depends on SPAPR_TCE_IOMMU
default VFIO
config VFIO_SPAPR_EEH
tristate
depends on EEH && VFIO_IOMMU_SPAPR_TCE
default VFIO
config VFIO_VIRQFD
tristate
select EVENTFD
default n
config VFIO_NOIOMMU
bool "VFIO No-IOMMU support"
help
VFIO is built on the ability to isolate devices using the IOMMU.
Only with an IOMMU can userspace access to DMA capable devices be
considered secure. VFIO No-IOMMU mode enables IOMMU groups for
devices without IOMMU backing for the purpose of re-using the VFIO
infrastructure in a non-secure mode. Use of this mode will result
in an unsupportable kernel and will therefore taint the kernel.
Device assignment to virtual machines is also not possible with
this mode since there is no IOMMU to provide DMA translation.
If you don't know what to do here, say N.
source "drivers/vfio/pci/Kconfig"
source "drivers/vfio/platform/Kconfig"
source "drivers/vfio/mdev/Kconfig"
source "drivers/vfio/fsl-mc/Kconfig"
endif
source "virt/lib/Kconfig"