Commit Graph

299 Commits

Author SHA1 Message Date
Akhilesh Patil
8fe8a09204 iommufd: viommu: free memory allocated by kvcalloc() using kvfree()
Use kvfree() instead of kfree() to free pages allocated by kvcalloc()
in iommufs_hw_queue_alloc_phys() to fix potential memory corruption.
Ensure the memory is properly freed, as kvcalloc may internally use
vmalloc or kmalloc depending on available memory in the system.

Fixes: 2238ddc2b0 ("iommufd/viommu: Add IOMMUFD_CMD_HW_QUEUE_ALLOC ioctl")
Link: https://patch.msgid.link/r/aJifyVV2PL6WGEs6@bhairav-test.ee.iitb.ac.in
Signed-off-by: Akhilesh Patil <akhilesh@ee.iitb.ac.in>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Pranjal Shrivastava <praan@google.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2025-08-18 11:10:40 -03:00
Linus Torvalds
c93529ad4f iommufd 6.17 merge window pull
- IOMMU HW now has features to directly assign HW command queues to a
   guest VM. In this mode the command queue operates on a limited set of
   invalidation commands that are suitable for improving guest invalidation
   performance and easy for the HW to virtualize.
 
   This PR brings the generic infrastructure to allow IOMMU drivers to
   expose such command queues through the iommufd uAPI, mmap the doorbell
   pages, and get the guest physical range for the command queue ring
   itself.
 
 - An implementation for the NVIDIA SMMUv3 extension "cmdqv" is built on
   the new iommufd command queue features. It works with the existing SMMU
   driver support for cmdqv in guest VMs.
 
 - Many precursor cleanups and improvements to support the above cleanly,
   changes to the general ioctl and object helpers, driver support for
   VDEVICE, and mmap pgoff cookie infrastructure.
 
 - Sequence VDEVICE destruction to always happen before VFIO device
   destruction. When using the above type features, and also in future
   confidential compute, the internal virtual device representation becomes
   linked to HW or CC TSM configuration and objects. If a VFIO device is
   removed from iommufd those HW objects should also be cleaned up to
   prevent a sort of UAF. This became important now that we have HW backing
   the VDEVICE.
 
 - Fix one syzkaller found error related to math overflows during iova
   allocation
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Merge tag 'for-linus-iommufd' of git://git.kernel.org/pub/scm/linux/kernel/git/jgg/iommufd

Pull iommufd updates from Jason Gunthorpe:
 "This broadly brings the assigned HW command queue support to iommufd.
  This feature is used to improve SVA performance in VMs by avoiding
  paravirtualization traps during SVA invalidations.

  Along the way I think some of the core logic is in a much better state
  to support future driver backed features.

  Summary:

   - IOMMU HW now has features to directly assign HW command queues to a
     guest VM. In this mode the command queue operates on a limited set
     of invalidation commands that are suitable for improving guest
     invalidation performance and easy for the HW to virtualize.

     This brings the generic infrastructure to allow IOMMU drivers to
     expose such command queues through the iommufd uAPI, mmap the
     doorbell pages, and get the guest physical range for the command
     queue ring itself.

   - An implementation for the NVIDIA SMMUv3 extension "cmdqv" is built
     on the new iommufd command queue features. It works with the
     existing SMMU driver support for cmdqv in guest VMs.

   - Many precursor cleanups and improvements to support the above
     cleanly, changes to the general ioctl and object helpers, driver
     support for VDEVICE, and mmap pgoff cookie infrastructure.

   - Sequence VDEVICE destruction to always happen before VFIO device
     destruction. When using the above type features, and also in future
     confidential compute, the internal virtual device representation
     becomes linked to HW or CC TSM configuration and objects. If a VFIO
     device is removed from iommufd those HW objects should also be
     cleaned up to prevent a sort of UAF. This became important now that
     we have HW backing the VDEVICE.

   - Fix one syzkaller found error related to math overflows during iova
     allocation"

* tag 'for-linus-iommufd' of git://git.kernel.org/pub/scm/linux/kernel/git/jgg/iommufd: (57 commits)
  iommu/arm-smmu-v3: Replace vsmmu_size/type with get_viommu_size
  iommu/arm-smmu-v3: Do not bother impl_ops if IOMMU_VIOMMU_TYPE_ARM_SMMUV3
  iommufd: Rename some shortterm-related identifiers
  iommufd/selftest: Add coverage for vdevice tombstone
  iommufd/selftest: Explicitly skip tests for inapplicable variant
  iommufd/vdevice: Remove struct device reference from struct vdevice
  iommufd: Destroy vdevice on idevice destroy
  iommufd: Add a pre_destroy() op for objects
  iommufd: Add iommufd_object_tombstone_user() helper
  iommufd/viommu: Roll back to use iommufd_object_alloc() for vdevice
  iommufd/selftest: Test reserved regions near ULONG_MAX
  iommufd: Prevent ALIGN() overflow
  iommu/tegra241-cmdqv: import IOMMUFD module namespace
  iommufd: Do not allow _iommufd_object_alloc_ucmd if abort op is set
  iommu/tegra241-cmdqv: Add IOMMU_VEVENTQ_TYPE_TEGRA241_CMDQV support
  iommu/tegra241-cmdqv: Add user-space use support
  iommu/tegra241-cmdqv: Do not statically map LVCMDQs
  iommu/tegra241-cmdqv: Simplify deinit flow in tegra241_cmdqv_remove_vintf()
  iommu/tegra241-cmdqv: Use request_threaded_irq
  iommu/arm-smmu-v3-iommufd: Add hw_info to impl_ops
  ...
2025-07-31 12:43:08 -07:00
Xu Yilun
ab6bc44159 iommufd: Rename some shortterm-related identifiers
Rename the shortterm-related identifiers to wait-related.

The usage of shortterm_users refcount is now beyond its name.  It is
also used for references which live longer than an ioctl execution.
E.g. vdev holds idev's shortterm_users refcount on vdev allocation,
releases it during idev's pre_destroy(). Rename the refcount as
wait_cnt, since it is always used to sync the referencing & the
destruction of the object by waiting for it to go to zero.

List all changed identifiers:

  iommufd_object::shortterm_users -> iommufd_object::wait_cnt
  REMOVE_WAIT_SHORTTERM -> REMOVE_WAIT
  iommufd_object_dec_wait_shortterm() -> iommufd_object_dec_wait()
  zerod_shortterm -> zerod_wait_cnt

No functional change intended.

Link: https://patch.msgid.link/r/20250716070349.1807226-9-yilun.xu@linux.intel.com
Suggested-by: Kevin Tian <kevin.tian@intel.com>
Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Nicolin Chen <nicolinc@nvidia.com>
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>
2025-07-18 17:33:08 -03:00
Xu Yilun
651f733675 iommufd/vdevice: Remove struct device reference from struct vdevice
Remove struct device *dev from struct vdevice.

The dev pointer is the Plan B for vdevice to reference the physical
device. As now vdev->idev is added without refcounting concern, just
use vdev->idev->dev when needed. To avoid exposing
struct iommufd_device in the public header, export a
iommufd_vdevice_to_device() helper.

Link: https://patch.msgid.link/r/20250716070349.1807226-6-yilun.xu@linux.intel.com
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Nicolin Chen <nicolinc@nvidia.com>
Co-developed-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
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>
2025-07-18 17:33:08 -03:00
Xu Yilun
850f14f5b9 iommufd: Destroy vdevice on idevice destroy
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>
2025-07-18 17:33:08 -03:00
Xu Yilun
7dc0e1090b iommufd: Add a pre_destroy() op for objects
Add a pre_destroy() op which gives objects a chance to clear their
short term users references before destruction. This op is intended for
external driver created objects (e.g. idev) which does deterministic
destruction.

In order to manage the lifecycle of interrelated objects as well as the
deterministic destruction (e.g. vdev can't outlive idev, and idev
destruction can't fail), short term users references are allowed to
live out of an ioctl execution. An immediate use case is, vdev holds
idev's short term user reference until vdev destruction completes, idev
leverages existing wait_shortterm mechanism to ensure it is destroyed
after vdev.

This extended usage makes the referenced object unable to just wait for
its reference gone. It needs to actively trigger the reference removal,
as well as prevent new references before wait. Should implement these
work in pre_destroy().

Link: https://patch.msgid.link/r/20250716070349.1807226-4-yilun.xu@linux.intel.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>
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>
2025-07-18 17:33:08 -03:00
Xu Yilun
e6d41ee312 iommufd: Add iommufd_object_tombstone_user() helper
Add the iommufd_object_tombstone_user() helper, which allows the caller
to destroy an iommufd object created by userspace.

This is useful on some destroy paths when the kernel caller finds the
object should have been removed by userspace but is still alive. With
this helper, the caller destroys the object but leave the object ID
reserved (so called tombstone). The tombstone prevents repurposing the
object ID without awareness of the original user.

Since this happens for abnormal userspace behavior, for simplicity, the
tombstoned object ID would be permanently leaked until
iommufd_fops_release(). I.e. the original user gets an error when
calling ioctl(IOMMU_DESTROY) on that ID.

The first use case would be to ensure the iommufd_vdevice can't outlive
the associated iommufd_device.

Link: https://patch.msgid.link/r/20250716070349.1807226-3-yilun.xu@linux.intel.com
Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.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>
2025-07-18 17:33:08 -03:00
Xu Yilun
a64bae68ad iommufd/viommu: Roll back to use iommufd_object_alloc() for vdevice
To solve the vdevice lifecycle issue, future patches make the vdevice
allocation protected by lock. That will make
_iommufd_object_alloc_ucmd() not applicable for vdevice. Roll back to
use _iommufd_object_alloc() for preparation.

Link: https://patch.msgid.link/r/20250716070349.1807226-2-yilun.xu@linux.intel.com
Reviewed-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
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>
2025-07-18 17:33:07 -03:00
Jason Gunthorpe
b42497e3c0 iommufd: Prevent ALIGN() overflow
When allocating IOVA the candidate range gets aligned to the target
alignment. If the range is close to ULONG_MAX then the ALIGN() can
wrap resulting in a corrupted iova.

Open code the ALIGN() using get_add_overflow() to prevent this.
This simplifies the checks as we don't need to check for length earlier
either.

Consolidate the two copies of this code under a single helper.

This bug would allow userspace to create a mapping that overlaps with some
other mapping or a reserved range.

Cc: stable@vger.kernel.org
Fixes: 51fe6141f0 ("iommufd: Data structure to provide IOVA to PFN mapping")
Reported-by: syzbot+c2f65e2801743ca64e08@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/r/685af644.a00a0220.2e5631.0094.GAE@google.com
Reviewed-by: Yi Liu <yi.l.liu@intel.com>
Reviewed-by: Nicolin Chen <nicolinc@nvidia.com>
Link: https://patch.msgid.link/all/1-v1-7b4a16fc390b+10f4-iommufd_alloc_overflow_jgg@nvidia.com/
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2025-07-17 11:46:55 -03:00
Nicolin Chen
5510bd89da iommufd: Do not allow _iommufd_object_alloc_ucmd if abort op is set
An abort op was introduced to allow its caller to invoke it within a lock
in the caller's function. On the other hand, _iommufd_object_alloc_ucmd()
would invoke the abort op in iommufd_object_abort_and_destroy() that must
be outside the caller's lock. So, these two cannot work together.

Add a validation in the _iommufd_object_alloc_ucmd(). Pick -EOPNOTSUPP to
reject the function call, indicating that the object allocator is buggy.

Link: https://patch.msgid.link/r/20250710202354.1658511-1-nicolinc@nvidia.com
Suggested-by: Xu Yilun <yilun.xu@linux.intel.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Xu Yilun <yilun.xu@linux.intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2025-07-14 13:46:27 -03:00
Nicolin Chen
a9f10bab2e iommufd: Allow an input data_type via iommu_hw_info
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>
2025-07-11 14:34:35 -03:00
Nicolin Chen
62622a8753 iommu: Allow an input type in hw_info op
The hw_info uAPI will support a bidirectional data_type field that can be
used as an input field for user space to request for a specific info data.

To prepare for the uAPI update, change the iommu layer first:
 - Add a new IOMMU_HW_INFO_TYPE_DEFAULT as an input, for which driver can
   output its only (or firstly) supported type
 - Update the kdoc accordingly
 - Roll out the type validation in the existing drivers

Link: https://patch.msgid.link/r/00f4a2d3d930721f61367014717b3ba2d1e82a81.1752126748.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>
2025-07-11 14:34:35 -03:00
Nicolin Chen
80478a2b45 iommufd/selftest: Add coverage for the new mmap interface
Extend the loopback test to a new mmap page.

Link: https://patch.msgid.link/r/b02b1220c955c3cf9ea5dd9fe9349ab1b4f8e20b.1752126748.git.nicolinc@nvidia.com
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Pranjal Shrivastava <praan@google.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2025-07-11 14:34:35 -03:00
Nicolin Chen
56e9a0d8e5 iommufd: Add mmap interface
For vIOMMU passing through HW resources to user space (VMs), allowing a VM
to control the passed through HW directly by accessing hardware registers,
add an mmap infrastructure to map the physical MMIO pages to user space.

Maintain a maple tree per ictx as a translation table managing mmappable
regions, from an allocated for-user mmap offset to an iommufd_mmap struct,
where it stores the real physical address range for io_remap_pfn_range().

Keep track of the lifecycle of the mmappable region by taking refcount of
its owner, so as to enforce user space to unmap the region first before it
can destroy its owner object.

To allow an IOMMU driver to add and delete mmappable regions onto/from the
maple tree, add iommufd_viommu_alloc/destroy_mmap helpers.

Link: https://patch.msgid.link/r/9a888a326b12aa5fe940083eae1156304e210fe0.1752126748.git.nicolinc@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Pranjal Shrivastava <praan@google.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.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>
2025-07-11 14:34:35 -03:00
Nicolin Chen
20896914da iommufd/selftest: Add coverage for IOMMUFD_CMD_HW_QUEUE_ALLOC
Some simple tests for IOMMUFD_CMD_HW_QUEUE_ALLOC infrastructure covering
the new iommufd_hw_queue_depend/undepend() helpers.

Link: https://patch.msgid.link/r/e8a194d187d7ef445f43e4a3c04fb39472050afd.1752126748.git.nicolinc@nvidia.com
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Pranjal Shrivastava <praan@google.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2025-07-11 11:09:26 -03:00
Nicolin Chen
0b37d892d0 iommufd/driver: Add iommufd_hw_queue_depend/undepend() helpers
NVIDIA Virtual Command Queue is one of the iommufd users exposing vIOMMU
features to user space VMs. Its hardware has a strict rule when mapping
and unmapping multiple global CMDQVs to/from a VM-owned VINTF, requiring
mappings in ascending order and unmappings in descending order.

The tegra241-cmdqv driver can apply the rule for a mapping in the LVCMDQ
allocation handler. However, it can't do the same for an unmapping since
user space could start random destroy calls breaking the rule, while the
destroy op in the driver level can't reject a destroy call as it returns
void.

Add iommufd_hw_queue_depend/undepend for-driver helpers, allowing LVCMDQ
allocator to refcount_inc() a sibling LVCMDQ object and LVCMDQ destroyer
to refcount_dec(), so that iommufd core will help block a random destroy
call that breaks the rule.

This is a bit of compromise, because a driver might end up with abusing
the API that deadlocks the objects. So restrict the API to a dependency
between two driver-allocated objects of the same type, as iommufd would
unlikely build any core-level dependency in this case. And encourage to
use the macro version that currently supports the HW QUEUE objects only.

Link: https://patch.msgid.link/r/2735c32e759c82f2e6c87cb32134eaf09b7589b5.1752126748.git.nicolinc@nvidia.com
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Pranjal Shrivastava <praan@google.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2025-07-11 11:09:26 -03:00
Nicolin Chen
2238ddc2b0 iommufd/viommu: Add IOMMUFD_CMD_HW_QUEUE_ALLOC ioctl
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>
2025-07-11 11:09:26 -03:00
Nicolin Chen
ed42eee797 iommufd/viommu: Add driver-defined vDEVICE support
NVIDIA VCMDQ driver will have a driver-defined vDEVICE structure and do
some HW configurations with that.

To allow IOMMU drivers to define their own vDEVICE structures, move the
struct iommufd_vdevice to the public header and provide a pair of viommu
ops, similar to get_viommu_size and viommu_init.

Doing this, however, creates a new window between the vDEVICE allocation
and its driver-level initialization, during which an abort could happen
but it can't invoke a driver destroy function from the struct viommu_ops
since the driver structure isn't initialized yet. vIOMMU object doesn't
have this problem, since its destroy op is set via the viommu_ops by the
driver viommu_init function. Thus, vDEVICE should do something similar:
add a destroy function pointer inside the struct iommufd_vdevice instead
of the struct iommufd_viommu_ops.

Note that there is unlikely a use case for a type dependent vDEVICE, so
a static vdevice_size is probably enough for the near term instead of a
get_vdevice_size function op.

Link: https://patch.msgid.link/r/1e751c01da7863c669314d8e27fdb89eabcf5605.1752126748.git.nicolinc@nvidia.com
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Pranjal Shrivastava <praan@google.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Vasant Hegde <vasant.hegde@amd.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2025-07-11 11:09:26 -03:00
Nicolin Chen
27b77ea5fe iommufd/access: Bypass access->ops->unmap for internal use
The access object has been used externally by VFIO mdev devices, allowing
them to pin/unpin physical pages (via needs_pin_pages). Meanwhile, a racy
unmap can occur in this case, so these devices usually implement an unmap
handler, invoked by iommufd_access_notify_unmap().

The new HW queue object will need the same pin/unpin feature, although it
(unlike the mdev case) wants to reject any unmap attempt, during its life
cycle. Instead, it would not implement an unmap handler. Thus, bypass any
access->ops->unmap access call when the access is marked as internal.

Also, an area being pinned by an internal access should reject any unmap
request. This cannot be done inside iommufd_access_notify_unmap() as it's
a per-iopt action. Add a "num_locks" counter in the struct iopt_area, set
that in iopt_area_add_access() when the caller is an internal access.

Link: https://patch.msgid.link/r/6df9a43febf79c0379091ec59747276ce9d2493b.1752126748.git.nicolinc@nvidia.com
Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Pranjal Shrivastava <praan@google.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2025-07-11 11:09:22 -03:00
Nicolin Chen
1c26c3bbde iommufd/access: Add internal APIs for HW queue to use
The new HW queue object, as an internal iommufd object, wants to reuse the
struct iommufd_access to pin some iova range in the iopt.

However, an access generally takes the refcount of an ictx. So, in such an
internal case, a deadlock could happen when the release of the ictx has to
wait for the release of the access first when releasing a hw_queue object,
which could wait for the release of the ictx that is refcounted:
    ictx --releases--> hw_queue --releases--> access
      ^                                         |
      |_________________releases________________v

To address this, add a set of lightweight internal APIs to unlink the ictx
and the access, i.e. no ictx refcounting by the access:
    ictx --releases--> hw_queue --releases--> access

Then, there's no point in setting the access->ictx. So simply define !ictx
as an flag for an internal use and add an inline helper.

Link: https://patch.msgid.link/r/d8d84bf99cbebec56034b57b966a3d431385b90d.1752126748.git.nicolinc@nvidia.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>
2025-07-10 12:38:51 -03:00
Nicolin Chen
afeaf592c1 iommufd/selftest: Support user_data in mock_viommu_alloc
Add a simple user_data for an input-to-output loopback test.

Link: https://patch.msgid.link/r/cae4632bb3d98a1efb3b77488fbf81814f2041c6.1752126748.git.nicolinc@nvidia.com
Reviewed-by: Pranjal Shrivastava <praan@google.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2025-07-10 12:38:51 -03:00
Nicolin Chen
1976cdf61c iommufd/viommu: Allow driver-specific user data for a vIOMMU object
The new type of vIOMMU for tegra241-cmdqv driver needs a driver-specific
user data. So, add data_len/uptr to the iommu_viommu_alloc uAPI and pass
it in via the viommu_init iommu op.

Link: https://patch.msgid.link/r/2315b0e164b355746387e960745ac9154caec124.1752126748.git.nicolinc@nvidia.com
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Acked-by: Pranjal Shrivastava <praan@google.com>
Acked-by: Alok Tiwari <alok.a.tiwari@oracle.com>
Reviewed-by: Vasant Hegde <vasant.hegde@amd.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2025-07-10 12:38:51 -03:00
Nicolin Chen
c3436d42f8 iommu: Pass in a driver-level user data structure to viommu_init op
The new type of vIOMMU for tegra241-cmdqv allows user space VM to use one
of its virtual command queue HW resources exclusively. This requires user
space to mmap the corresponding MMIO page from kernel space for direct HW
control.

To forward the mmap info (offset and length), iommufd should add a driver
specific data structure to the IOMMUFD_CMD_VIOMMU_ALLOC ioctl, for driver
to output the info during the vIOMMU initialization back to user space.

Similar to the existing ioctls and their IOMMU handlers, add a user_data
to viommu_init op to bridge between iommufd and drivers.

Link: https://patch.msgid.link/r/90bd5637dab7f5507c7a64d2c4826e70431e45a4.1752126748.git.nicolinc@nvidia.com
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Pranjal Shrivastava <praan@google.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Vasant Hegde <vasant.hegde@amd.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2025-07-10 12:38:51 -03:00
Nicolin Chen
4b57c057f9 iommu: Use enum iommu_hw_info_type for type in hw_info op
Replace u32 to make it clear. No functional changes.

Also simplify the kdoc since the type itself is clear enough.

Link: https://patch.msgid.link/r/651c50dee8ab900f691202ef0204cd5a43fdd6a2.1752126748.git.nicolinc@nvidia.com
Reviewed-by: Pranjal Shrivastava <praan@google.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>
2025-07-10 12:38:50 -03:00
Nicolin Chen
c50a5de2c4 iommufd/viommu: Explicitly define vdev->virt_id
The "id" is too general to get its meaning easily. Rename it explicitly to
"virt_id" and update the kdocs for readability. No functional changes.

Link: https://patch.msgid.link/r/1fac22d645e6ee555675726faf3798a68315b044.1752126748.git.nicolinc@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Pranjal Shrivastava <praan@google.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Vasant Hegde <vasant.hegde@amd.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2025-07-10 12:38:50 -03:00
Nicolin Chen
b23e09f999 iommufd: Report unmapped bytes in the error path of iopt_unmap_iova_range
There are callers that read the unmapped bytes even when rc != 0. Thus, do
not forget to report it in the error path too.

Fixes: 8d40205f60 ("iommufd: Add kAPI toward external drivers for kernel access")
Link: https://patch.msgid.link/r/e2b61303bbc008ba1a4e2d7c2a2894749b59fdac.1752126748.git.nicolinc@nvidia.com
Cc: stable@vger.kernel.org
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>
2025-07-10 12:38:50 -03:00
Jason Gunthorpe
8901812485 iommu: Remove ops.pgsize_bitmap from drivers that don't use it
These drivers all set the domain->pgsize_bitmap in their
domain_alloc_paging() functions, so the ops value is never used. Delete
it.

Reviewed-by: Sven Peter <sven@svenpeter.dev> # for Apple DART
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Tomasz Jeznach <tjeznach@rivosinc.com> # for RISC-V
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Link: https://lore.kernel.org/r/3-v2-68a2e1ba507c+1fb-iommu_rm_ops_pgsize_jgg@nvidia.com
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2025-06-27 08:55:56 +02:00
Nicolin Chen
3e2a9811f6 iommufd: Apply the new iommufd_object_alloc_ucmd helper
Now the new ucmd-based object allocator eases the finalize/abort routine,
apply this to all existing allocators that aren't protected by any lock.

Upgrade the for-driver vIOMMU alloctor too, and pass down to all existing
viommu_alloc op accordingly.

Note that __iommufd_object_alloc_ucmd() builds in some static tests that
cover both static_asserts in the iommufd_viommu_alloc(). Thus drop them.

Link: https://patch.msgid.link/r/107b24a3b791091bb09c92ffb0081c56c413b26d.1749882255.git.nicolinc@nvidia.com
Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2025-06-19 15:43:30 -03:00
Nicolin Chen
c0d498a1b9 iommufd: Introduce iommufd_object_alloc_ucmd helper
An object allocator needs to call either iommufd_object_finalize() upon a
success or iommufd_object_abort_and_destroy() upon an error code.

To reduce duplication, store a new_obj in the struct iommufd_ucmd and call
iommufd_object_finalize/iommufd_object_abort_and_destroy() accordingly in
the main function.

Similar to iommufd_object_alloc() and __iommufd_object_alloc(), add a pair
of helpers: __iommufd_object_alloc_ucmd() and iommufd_object_alloc_ucmd().

Link: https://patch.msgid.link/r/e7206d4227844887cc8dbf0cc7b0242580fafd9d.1749882255.git.nicolinc@nvidia.com
Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Acked-by: Pranjal Shrivastava <praan@google.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2025-06-19 15:43:29 -03:00
Nicolin Chen
17a93473a5 iommufd: Move _iommufd_object_alloc out of driver.c
Now, all driver structures will be allocated by the core, i.e. no longer a
need of driver calling _iommufd_object_alloc. Thus, move it back.

Before:
   text	   data	    bss	    dec	    hex	filename
   3024	    180	      0	   3204	    c84	drivers/iommu/iommufd/driver.o
   9074	    610	     64	   9748	   2614	drivers/iommu/iommufd/main.o
After:
   text	   data	    bss	    dec	    hex	filename
   2665	    164	      0	   2829	    b0d	drivers/iommu/iommufd/driver.o
   9410	    618	     64	  10092	   276c	drivers/iommu/iommufd/main.o

Link: https://patch.msgid.link/r/79e630c7b911930cf36e3c8a775a04e66c528d65.1749882255.git.nicolinc@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2025-06-19 15:43:29 -03:00
Nicolin Chen
f842ea208e iommu: Deprecate viommu_alloc op
To ease the for-driver iommufd APIs, get_viommu_size and viommu_init ops
are introduced. Now, those existing vIOMMU supported drivers implemented
these two ops, replacing the viommu_alloc one. So, there is no use of it.

Remove it from the headers and the viommu core.

Link: https://patch.msgid.link/r/5b32d4499d7ed02a63e57a293c11b642d226ef8d.1749882255.git.nicolinc@nvidia.com
Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Pranjal Shrivastava <praan@google.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2025-06-19 15:43:29 -03:00
Nicolin Chen
683cff7c3b iommufd/selftest: Replace mock_viommu_alloc with mock_viommu_init
To ease the for-driver iommufd APIs, get_viommu_size and viommu_init ops
are introduced.

Sanitize the inputs and report the size of struct mock_viommu on success,
in mock_get_viommu_size().

The core will ensure the viommu_type is set to the core vIOMMU object, so
simply init the driver part in mock_viommu_init().

Remove the mock_viommu_alloc, completing the replacement.

Link: https://patch.msgid.link/r/993beabbb0bc9705d979a92801ea5ed5996a34eb.1749882255.git.nicolinc@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2025-06-19 15:43:29 -03:00
Nicolin Chen
5983d1e7d7 iommufd/selftest: Drop parent domain from mock_iommu_domain_nested
There is no use of this parent domain. Delete the dead code.

Note that the s2_parent in struct mock_viommu will be a deadcode too. Yet,
keep it because it will be soon used by HW queue objects, i.e. no point in
adding it back and forth in such a short window. Besides, keeping it could
cover the majority of vIOMMU use cases where a driver-level structure will
be larger in size than the core structure.

Link: https://patch.msgid.link/r/0f155a7cd71034a498448fe4828fb4aaacdabf95.1749882255.git.nicolinc@nvidia.com
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2025-06-19 15:43:29 -03:00
Nicolin Chen
63141fa741 iommufd/viommu: Support get_viommu_size and viommu_init ops
To ease the for-driver iommufd APIs, get_viommu_size and viommu_init ops
are introduced to replace the viommu_init op.

Let the new viommu_init pathway coexist with the old viommu_alloc one.

Since the viommu_alloc op and its pathway will be soon deprecated, try to
minimize the code difference between them by adding a tentative jump tag.

Note that this fails a !viommu->ops case from now on with a WARN_ON_ONCE
since a vIOMMU is expected to support an alloc_domain_nested op for now,
or some sort of a viommu op in the foreseeable future. This WARN_ON_ONCE
can be lifted, if some day there is a use case wanting !viommu->ops.

Link: https://patch.msgid.link/r/35c5fa5926be45bda82f5fc87545cd3180ad4c9c.1749882255.git.nicolinc@nvidia.com
Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2025-06-19 15:43:28 -03:00
Nicolin Chen
0c6e0ae7a7 iommufd: Return EOPNOTSUPP for failures due to driver bugs
It's more accurate to report EOPNOTSUPP when an ioctl failed due to driver
bug, since there is nothing wrong with the user space side.

Link: https://patch.msgid.link/r/623bb6f0e8fdd7b9c5745a2f99f280163f9f1f5a.1749882255.git.nicolinc@nvidia.com
Signed-off-by: Nicolin Chen <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: Jason Gunthorpe <jgg@nvidia.com>
2025-06-19 15:43:28 -03:00
Nicolin Chen
62b62a55bd iommufd: Use enum iommu_veventq_type for type in struct iommufd_veventq
Replace unsigned int, to make it clear. No functional changes.

Link: https://patch.msgid.link/r/208a260c100a00667d3799feaad1260745f96c6b.1749882255.git.nicolinc@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Pranjal Shrivastava <praan@google.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2025-06-19 15:43:28 -03:00
Nicolin Chen
6e235a7721 iommufd: Drop unused ictx in struct iommufd_vdevice
The core code can always get the ictx pointer via vdev->viommu->ictx, thus
drop this unused one.

Link: https://patch.msgid.link/r/6cbb65e8df433de45b6c3a4bb2c5df09faca8a7c.1749882255.git.nicolinc@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2025-06-19 15:43:27 -03:00
Nicolin Chen
ea92128fe7 iommufd: Apply obvious cosmetic fixes
Run clang-format but exclude those not so obvious ones, which leaves us:
 - Align indentations
 - Add missing spaces
 - Remove unnecessary spaces
 - Remove unnecessary line wrappings

Link: https://patch.msgid.link/r/9132e1ab45690ab1959c66bbb51ac5536a635388.1749882255.git.nicolinc@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2025-06-19 15:43:27 -03:00
Lu Baolu
be2a24322c iommufd: Remove unnecessary IOMMU_DEV_FEAT_IOPF
The iopf enablement has been moved to the iommu drivers. It is unnecessary
for iommufd to handle iopf enablement. Remove the iopf enablement logic to
avoid duplication.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Tested-by: Zhangfei Gao <zhangfei.gao@linaro.org>
Link: https://lore.kernel.org/r/20250418080130.1844424-8-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2025-04-28 13:04:34 +02:00
Lu Baolu
c2fa4d4cce iommufd/selftest: Put iopf enablement in domain attach path
Update iopf enablement in the iommufd mock device driver to use the new
method, similar to the arm-smmu-v3 driver. Enable iopf support when any
domain with an iopf_handler is attached, and disable it when the domain
is removed.

Add a refcount in the mock device state structure to keep track of the
number of domains set to the device and PASIDs that require iopf.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Yi Liu <yi.l.liu@intel.com>
Reviewed-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Zhangfei Gao <zhangfei.gao@linaro.org>
Link: https://lore.kernel.org/r/20250418080130.1844424-5-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2025-04-28 13:04:33 +02:00
Yi Liu
7be11d34f6 iommufd: Test attach before detaching pasid
Check if the pasid has been attached before going further in the detach
path. This fixes a crash found by syzkaller. Add a selftest as well.

   Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASI
   KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
   CPU: 1 UID: 0 PID: 668 Comm: repro Not tainted 6.14.0-next-20250325-eb4bc4b07f66 #1 PREEMPT(voluntary)
   Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org4
   RIP: 0010:iommufd_hw_pagetable_detach+0x8a/0x4d0
   Code: 00 00 00 44 89 ee 48 89 c7 48 89 75 c8 48 89 45 c0 e8 ca 55 17 02 48 89 c2 49 89 c4 48 b8 00 00 00b
   RSP: 0018:ffff888021b17b78 EFLAGS: 00010246
   RAX: dffffc0000000000 RBX: ffff888014b5a000 RCX: ffff888021b17a64
   RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88801dad07fc
   RBP: ffff888021b17bc8 R08: 0000000000000001 R09: 0000000000000001
   R10: 0000000000000001 R11: ffff88801dad0e58 R12: 0000000000000000
   R13: 0000000000000001 R14: ffff888021b17e18 R15: ffff8880132d3008
   FS:  00007fca52013600(0000) GS:ffff8880e3684000(0000) knlGS:0000000000000000
   CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
   CR2: 00000000200006c0 CR3: 00000000112d0005 CR4: 0000000000770ef0
   DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
   DR3: 0000000000000000 DR6: 00000000ffff07f0 DR7: 0000000000000400
   PKRU: 55555554
   Call Trace:
    <TASK>
    iommufd_device_detach+0x2a/0x2e0
    iommufd_test+0x2f99/0x5cd0
    iommufd_fops_ioctl+0x38e/0x520
    __x64_sys_ioctl+0x1ba/0x220
    x64_sys_call+0x122e/0x2150
    do_syscall_64+0x6d/0x150
    entry_SYSCALL_64_after_hwframe+0x76/0x7e

Link: https://patch.msgid.link/r/20250328133448.22052-1-yi.l.liu@intel.com
Reported-by: Lai Yi <yi1.lai@linux.intel.com>
Closes: https://lore.kernel.org/linux-iommu/Z+X0tzxhiaupJT7b@ly-workstation
Fixes: c0e301b297 ("iommufd/device: Add pasid_attach array to track per-PASID attach")
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2025-03-28 11:40:41 -03:00
Yi Liu
6fc85bbbea iommufd: Balance veventq->num_events inc/dec
iommufd_veventq_fops_read() decrements veventq->num_events when a vevent
is read out. However, the report path ony increments veventq->num_events
for normal events. To be balanced, make the read path decrement num_events
only for normal vevents.

Fixes: e36ba5ab80 ("iommufd: Add IOMMUFD_OBJ_VEVENTQ and IOMMUFD_CMD_VEVENTQ_ALLOC")
Link: https://patch.msgid.link/r/20250324120034.5940-3-yi.l.liu@intel.com
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Reviewed-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2025-03-28 10:07:23 -03:00
Yi Liu
41464a4628 iommufd: Initialize the flags of vevent in iommufd_viommu_report_event()
The vevent->header.flags is not initialized per allocation, hence the
vevent read path may treat the vevent as lost_events_header wrongly.
Use kzalloc() to alloc memory for new vevent.

Fixes: e8e1ef9b77 ("iommufd/viommu: Add iommufd_viommu_report_event helper")
Link: https://patch.msgid.link/r/20250324120034.5940-2-yi.l.liu@intel.com
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Reviewed-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2025-03-28 10:07:23 -03:00
Yi Liu
803f97298e iommufd: Extend IOMMU_GET_HW_INFO to report PASID capability
PASID usage requires PASID support in both device and IOMMU. Since the
iommu drivers always enable the PASID capability for the device if it
is supported, this extends the IOMMU_GET_HW_INFO to report the PASID
capability to userspace. Also, enhances the selftest accordingly.

Link: https://patch.msgid.link/r/20250321180143.8468-5-yi.l.liu@intel.com
Cc: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Tested-by: Zhangfei Gao <zhangfei.gao@linaro.org> #aarch64 platform
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2025-03-28 10:07:23 -03:00
Yi Liu
c1b52b0a97 iommufd/selftest: Add test ops to test pasid attach/detach
This adds 4 test ops for pasid attach/replace/detach testing. There are
ops to attach/detach pasid, and also op to check the attached hwpt of a
pasid.

Link: https://patch.msgid.link/r/20250321171940.7213-18-yi.l.liu@intel.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2025-03-25 10:18:31 -03:00
Yi Liu
068e140251 iommufd/selftest: Add a helper to get test device
There is need to get the selftest device (sobj->type == TYPE_IDEV) in
multiple places, so have a helper to for it.

Link: https://patch.msgid.link/r/20250321171940.7213-17-yi.l.liu@intel.com
Reviewed-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2025-03-25 10:18:31 -03:00
Yi Liu
9eb59204d5 iommufd/selftest: Add set_dev_pasid in mock iommu
The callback is needed to make pasid_attach/detach path complete for mock
device. A nop is enough for set_dev_pasid.

A MOCK_FLAGS_DEVICE_PASID is added to indicate a pasid-capable mock device
for the pasid test cases. Other test cases will still create a non-pasid
mock device. While the mock iommu always pretends to be pasid-capable.

Link: https://patch.msgid.link/r/20250321171940.7213-16-yi.l.liu@intel.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2025-03-25 10:18:31 -03:00
Yi Liu
dbc5f37b4f iommufd: Allow allocating PASID-compatible domain
The underlying infrastructure has supported the PASID attach and related
enforcement per the requirement of the IOMMU_HWPT_ALLOC_PASID flag. This
extends iommufd to support PASID compatible domain requested by userspace.

Link: https://patch.msgid.link/r/20250321171940.7213-15-yi.l.liu@intel.com
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2025-03-25 10:18:31 -03:00
Yi Liu
4c3f4f432c iommufd: Enforce PASID-compatible domain for RID
Per the definition of IOMMU_HWPT_ALLOC_PASID, iommufd needs to enforce
the RID to use PASID-compatible domain if PASID has been attached, and
vice versa. The PASID path has already enforced it. This adds the
enforcement in the RID path.

This enforcement requires a lock across the RID and PASID attach path,
the idev->igroup->lock is used as both the RID and the PASID path holds
it.

Link: https://patch.msgid.link/r/20250321171940.7213-13-yi.l.liu@intel.com
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2025-03-25 10:18:31 -03:00
Yi Liu
2fb69c602d iommufd: Support pasid attach/replace
This extends the below APIs to support PASID. Device drivers to manage pasid
attach/replace/detach.

    int iommufd_device_attach(struct iommufd_device *idev,
			      ioasid_t pasid, u32 *pt_id);
    int iommufd_device_replace(struct iommufd_device *idev,
			       ioasid_t pasid, u32 *pt_id);
    void iommufd_device_detach(struct iommufd_device *idev,
			       ioasid_t pasid);

The pasid operations share underlying attach/replace/detach infrastructure
with the device operations, but still have some different implications:

 - no reserved region per pasid otherwise SVA architecture is already
   broken (CPU address space doesn't count device reserved regions);

 - accordingly no sw_msi trick;

Cache coherency enforcement is still applied to pasid operations since
it is about memory accesses post page table walking (no matter the walk
is per RID or per PASID).

Link: https://patch.msgid.link/r/20250321171940.7213-12-yi.l.liu@intel.com
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2025-03-25 10:18:31 -03:00