IOMMU_IOAS_MAP_FILE is documented as mapping a memfd, but the
implementation first tries to resolve the fd as a dma-buf and has a
special path for supported dma-buf exporters. In particular, VFIO PCI
dma-bufs exported through VFIO_DEVICE_FEATURE_DMA_BUF can be mapped when
they describe a single DMA range.
Update the UAPI comment so userspace understands that certain kinds of
dma-buf are supported in addition to memfd.
Fixes: 44ebaa1744 ("iommufd: Accept a DMABUF through IOMMU_IOAS_MAP_FILE")
Link: https://patch.msgid.link/r/20260610-tmp-v1-1-b8ccbf557391@fb.com
Signed-off-by: Alex Mastro <amastro@fb.com>
Assisted-by: Codex:gpt-5.5-high
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
>From hardware implementation perspective, a guest tegra241-cmdqv hardware
is different than the host hardware:
- Host HW is backed by a VINTF (HYP_OWN=1)
- Guest HW is backed by a VINTF (HYP_OWN=0)
The kernel driver has an implementation requirement of the HYP_OWN bit in
the VM. So, VMM must follow that to allow the same copy of Linux to work.
Add this requirement to the uAPI, which is currently missing.
Fixes: 4dc0d12474 ("iommu/tegra241-cmdqv: Add user-space use support")
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Will Deacon <will@kernel.org>
If the IOMMU driver reports that ATS is not supported for a device, set
the IOMMU_HW_CAP_PCI_ATS_NOT_SUPPORTED flag in the returned hardware
capabilities.
This uses a negative flag for UAPI compatibility. Existing userspace
assumes ATS is supported if no flag is present. This also ensures that
new userspace works correctly on both old and new kernels, where a
zero value implies ATS support.
When this flag is set, ATS cannot be used for the device. When it is
clear, ATS may be enabled when an appropriate HWPT is attached.
Reviewed-by: Samiullah Khawaja <skhawaja@google.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Shameer Kolothum <skolothumtho@nvidia.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Introduce IOMMU_HWPT_DATA_AMD_GUEST data type for IOMMU guest page table,
which is used for stage-1 in nested translation. The data structure
contains information necessary for setting up the AMD HW-vIOMMU support.
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Vasant Hegde <vasant.hegde@amd.com>
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
AMD IOMMU Extended Feature (EFR) and Extended Feature 2 (EFR2) registers
specify features supported by each IOMMU hardware instance.
The IOMMU driver checks each feature-specific bits before enabling
each feature at run time.
For IOMMUFD, the hypervisor passes the raw value of amd_iommu_efr and
amd_iommu_efr2 to VMM via iommufd IOMMU_DEVICE_GET_HW_INFO ioctl.
Reviewed-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Vasant Hegde <vasant.hegde@amd.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
A vDEVICE has been a hard requirement for attaching a nested domain to the
device. This makes sense when installing a guest STE, since a vSID must be
present and given to the kernel during the vDEVICE allocation.
But, when CR0.SMMUEN is disabled, VM doesn't really need a vSID to program
the vSMMU behavior as GBPA will take effect, in which case the vSTE in the
nested domain could have carried the bypass or abort configuration in GBPA
register. Thus, having such a hard requirement doesn't work well for GBPA.
Skip vmaster allocation in arm_smmu_attach_prepare_vmaster() for an abort
or bypass vSTE. Note that device on this attachment won't report vevents.
Update the uAPI doc accordingly.
Link: https://patch.msgid.link/r/20251103172755.2026145-1-nicolinc@nvidia.com
Tested-by: Shameer Kolothum <skolothumtho@nvidia.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Pranjal Shrivastava <praan@google.com>
Tested-by: Shuai Xue <xueshuai@linux.alibaba.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Destroy iommufd_vdevice (vdev) on iommufd_idevice (idev) destruction so
that vdev can't outlive idev.
idev represents the physical device bound to iommufd, while the vdev
represents the virtual instance of the physical device in the VM. The
lifecycle of the vdev should not be longer than idev. This doesn't
cause real problem on existing use cases cause vdev doesn't impact the
physical device, only provides virtualization information. But to
extend vdev for Confidential Computing (CC), there are needs to do
secure configuration for the vdev, e.g. TSM Bind/Unbind. These
configurations should be rolled back on idev destroy, or the external
driver (VFIO) functionality may be impact.
The idev is created by external driver so its destruction can't fail.
The idev implements pre_destroy() op to actively remove its associated
vdev before destroying itself. There are 3 cases on idev pre_destroy():
1. vdev is already destroyed by userspace. No extra handling needed.
2. vdev is still alive. Use iommufd_object_tombstone_user() to
destroy vdev and tombstone the vdev ID.
3. vdev is being destroyed by userspace. The vdev ID is already
freed, but vdev destroy handler is not completed. This requires
multi-threads syncing - vdev holds idev's short term users
reference until vdev destruction completes, idev leverages
existing wait_shortterm mechanism for syncing.
idev should also block any new reference to it after pre_destroy(),
or the following wait shortterm would timeout. Introduce a 'destroying'
flag, set it to true on idev pre_destroy(). Any attempt to reference
idev should honor this flag under the protection of
idev->igroup->lock.
Link: https://patch.msgid.link/r/20250716070349.1807226-5-yilun.xu@linux.intel.com
Originally-by: Nicolin Chen <nicolinc@nvidia.com>
Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Co-developed-by: "Aneesh Kumar K.V (Arm)" <aneesh.kumar@kernel.org>
Signed-off-by: "Aneesh Kumar K.V (Arm)" <aneesh.kumar@kernel.org>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Xu Yilun <yilun.xu@linux.intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
The CMDQV HW supports a user-space use for virtualization cases. It allows
the VM to issue guest-level TLBI or ATC_INV commands directly to the queue
and executes them without a VMEXIT, as HW will replace the VMID field in a
TLBI command and the SID field in an ATC_INV command with the preset VMID
and SID.
This is built upon the vIOMMU infrastructure by allowing VMM to allocate a
VINTF (as a vIOMMU object) and assign VCMDQs (HW QUEUE objs) to the VINTF.
So firstly, replace the standard vSMMU model with the VINTF implementation
but reuse the standard cache_invalidate op (for unsupported commands) and
the standard alloc_domain_nested op (for standard nested STE).
Each VINTF has two 64KB MMIO pages (128B per logical VCMDQ):
- Page0 (directly accessed by guest) has all the control and status bits.
- Page1 (trapped by VMM) has guest-owned queue memory location/size info.
VMM should trap the emulated VINTF0's page1 of the guest VM for the guest-
level VCMDQ location/size info and forward that to the kernel to translate
to a physical memory location to program the VCMDQ HW during an allocation
call. Then, it should mmap the assigned VINTF's page0 to the VINTF0 page0
of the guest VM. This allows the guest OS to read and write the guest-own
VINTF's page0 for direct control of the VCMDQ HW.
For ATC invalidation commands that hold an SID, it requires all devices to
register their virtual SIDs to the SID_MATCH registers and their physical
SIDs to the pairing SID_REPLACE registers, so that HW can use those as a
lookup table to replace those virtual SIDs with the correct physical SIDs.
Thus, implement the driver-allocated vDEVICE op with a tegra241_vintf_sid
structure to allocate SID_REPLACE and to program the SIDs accordingly.
This enables the HW accelerated feature for NVIDIA Grace CPU. Compared to
the standard SMMUv3 operating in the nested translation mode trapping CMDQ
for TLBI and ATC_INV commands, this gives a huge performance improvement:
70% to 90% reductions of invalidation time were measured by various DMA
unmap tests running in a guest OS.
Link: https://patch.msgid.link/r/fb0eab83f529440b6aa181798912a6f0afa21eb0.1752126748.git.nicolinc@nvidia.com
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Pranjal Shrivastava <praan@google.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
The iommu_hw_info can output via the out_data_type field the vendor data
type from a driver, but this only allows driver to report one data type.
Now, with SMMUv3 having a Tegra241 CMDQV implementation, it has two sets
of types and data structs to report.
One way to support that is to use the same type field bidirectionally.
Reuse the same field by adding an "in_data_type", allowing user space to
request for a specific type and to get the corresponding data.
For backward compatibility, since the ioctl handler has never checked an
input value, add an IOMMU_HW_INFO_FLAG_INPUT_TYPE to switch between the
old output-only field and the new bidirectional field.
Link: https://patch.msgid.link/r/887378a7167e1786d9d13cde0c36263ed61823d7.1752126748.git.nicolinc@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Pranjal Shrivastava <praan@google.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Introduce a new IOMMUFD_CMD_HW_QUEUE_ALLOC ioctl for user space to allocate
a HW QUEUE object for a vIOMMU specific HW-accelerated queue, e.g.:
- NVIDIA's Virtual Command Queue
- AMD vIOMMU's Command Buffer, Event Log Buffers, and PPR Log Buffers
Since this is introduced with NVIDIA's VCMDQs that access the guest memory
in the physical address space, add an iommufd_hw_queue_alloc_phys() helper
that will create an access object to the queue memory in the IOAS, to avoid
the mappings of the guest memory from being unmapped, during the life cycle
of the HW queue object.
AMD's HW will need an hw_queue_init op that is mutually exclusive with the
hw_queue_init_phys op, and their case will bypass the access part, i.e. no
iommufd_hw_queue_alloc_phys() call.
Link: https://patch.msgid.link/r/dab4ace747deb46c1fe70a5c663307f46990ae56.1752126748.git.nicolinc@nvidia.com
Reviewed-by: Pranjal Shrivastava <praan@google.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Add IOMMUFD_OBJ_HW_QUEUE with an iommufd_hw_queue structure, representing
a HW-accelerated queue type of IOMMU's physical queue that can be passed
through to a user space VM for direct hardware control, such as:
- NVIDIA's Virtual Command Queue
- AMD vIOMMU's Command Buffer, Event Log Buffers, and PPR Log Buffers
Add new viommu ops for iommufd to communicate with IOMMU drivers to fetch
supported HW queue structure size and to forward user space ioctls to the
IOMMU drivers for initialization/destroy.
As the existing HWs, NVIDIA's VCMDQs access the guest memory via physical
addresses, while AMD's Buffers access the guest memory via guest physical
addresses (i.e. iova of the nesting parent HWPT). Separate two mutually
exclusive hw_queue_init and hw_queue_init_phys ops to indicate whether a
vIOMMU HW accesses the guest queue in the guest physical space (via iova)
or the host physical space (via pa).
In a latter case, the iommufd core will validate the physical pages of a
given guest queue, to ensure the underlying physical pages are contiguous
and pinned.
Since this is introduced with NVIDIA's VCMDQs, add hw_queue_init_phys for
now, and leave some notes for hw_queue_init in the near future (for AMD).
Either NVIDIA's or AMD's HW is a multi-queue model: NVIDIA's will be only
one type in enum iommu_hw_queue_type, while AMD's will be three different
types (two of which will have multi queues). Compared to letting the core
manage multiple queues with three types per vIOMMU object, it'd be easier
for the driver to manage that by having three different driver-structure
arrays per vIOMMU object. Thus, pass in the index to the init op.
Link: https://patch.msgid.link/r/6939b73699e278e60ce167e911b3d9be68882bad.1752126748.git.nicolinc@nvidia.com
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Pranjal Shrivastava <praan@google.com>
Reviewed-by: Vasant Hegde <vasant.hegde@amd.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Stephen Rothwell reports htmldocs warnings on iommufd_vevent_header
tables:
Documentation/userspace-api/iommufd:323: ./include/uapi/linux/iommufd.h:1048: CRITICAL: Unexpected section title or transition.
------------------------------------------------------------------------- [docutils]
WARNING: kernel-doc './scripts/kernel-doc -rst -enable-lineno -sphinx-version 8.1.3 ./include/uapi/linux/iommufd.h' processing failed with: Documentation/userspace-api/iommufd:323: ./include/uapi/linux/iommufd.h:1048: (SEVERE/4) Unexpected section title or transition.
-------------------------------------------------------------------------
These are because Sphinx confuses the tables for section headings. Fix
the table markup to squash away above warnings.
Fixes: e36ba5ab80 ("iommufd: Add IOMMUFD_OBJ_VEVENTQ and IOMMUFD_CMD_VEVENTQ_ALLOC")
Link: https://patch.msgid.link/r/20250328114654.55840-1-bagasdotme@gmail.com
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Closes: https://lore.kernel.org/linux-next/20250318213359.5dc56fd1@canb.auug.org.au/
Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Pull iommu updates from Joerg Roedel:
"Core Updates:
- Convert call-sites using iommu_domain_alloc() to more specific
versions and remove function
- Introduce iommu_paging_domain_alloc_flags()
- Extend support for allocating PASID-capable domains to more drivers
- Remove iommu_present()
- Some smaller improvements
New IOMMU driver for RISC-V
Intel VT-d Updates:
- Add domain_alloc_paging support
- Enable user space IOPFs in non-PASID and non-svm cases
- Small code refactoring and cleanups
- Add domain replacement support for pasid
AMD-Vi Updates:
- Adapt to iommu_paging_domain_alloc_flags() interface and alloc V2
page-tables by default
- Replace custom domain ID allocator with IDA allocator
- Add ops->release_domain() support
- Other improvements to device attach and domain allocation code
paths
ARM-SMMU Updates:
- SMMUv2:
- Return -EPROBE_DEFER for client devices probing before their
SMMU
- Devicetree binding updates for Qualcomm MMU-500 implementations
- SMMUv3:
- Minor fixes and cleanup for NVIDIA's virtual command queue
driver
- IO-PGTable:
- Fix indexing of concatenated PGDs and extend selftest coverage
- Remove unused block-splitting support
S390 IOMMU:
- Implement support for blocking domain
Mediatek IOMMU:
- Enable 35-bit physical address support for mt8186
OMAP IOMMU driver:
- Adapt to recent IOMMU core changes and unbreak driver"
* tag 'iommu-updates-v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/iommu/linux: (92 commits)
iommu/tegra241-cmdqv: Fix alignment failure at max_n_shift
iommu: Make set_dev_pasid op support domain replacement
iommu/arm-smmu-v3: Make set_dev_pasid() op support replace
iommu/vt-d: Add set_dev_pasid callback for nested domain
iommu/vt-d: Make identity_domain_set_dev_pasid() to handle domain replacement
iommu/vt-d: Make intel_svm_set_dev_pasid() support domain replacement
iommu/vt-d: Limit intel_iommu_set_dev_pasid() for paging domain
iommu/vt-d: Make intel_iommu_set_dev_pasid() to handle domain replacement
iommu/vt-d: Add iommu_domain_did() to get did
iommu/vt-d: Consolidate the struct dev_pasid_info add/remove
iommu/vt-d: Add pasid replace helpers
iommu/vt-d: Refactor the pasid setup helpers
iommu/vt-d: Add a helper to flush cache for updating present pasid entry
iommu: Pass old domain to set_dev_pasid op
iommu/iova: Fix typo 'adderss'
iommu: Add a kdoc to iommu_unmap()
iommu/io-pgtable-arm-v7s: Remove split on unmap behavior
iommu/io-pgtable-arm: Remove split on unmap behavior
iommu/vt-d: Drain PRQs when domain removed from RID
iommu/vt-d: Drop pasid requirement for prq initialization
...
