Commit Graph

544 Commits

Author SHA1 Message Date
Jason Gunthorpe
0735c54804 iommu: Handle unmap error when iommu_debug is enabled
Sashiko noticed a latent bug where the map error flow called iommu_unmap()
which calls iommu_debug_unmap_begin()/iommu_debug_unmap_end() however
since this is an error path the map flow never actually established the
original iommu_debug_map() it will malfunction.

Lift the unmap error handling into iommu_map_nosync() and reorder it so
the trace_map()/iommu_debug_map() records the partial mapping and then
immediately unmaps it. This avoid creating the unbalanced tracking and
provides saner tracing instead of a unmap unmatched to any map.

Fixes: ccc21213f0 ("iommu: Add calls for IOMMU_DEBUG_PAGEALLOC")
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Pranjal Shrivastava <praan@google.com>
Reviewed-by: Samiullah Khawaja <skhawaja@google.com>
Reviewed-by: Mostafa Saleh <smostafa@google.com>
Tested-by: Josua Mayer <josua@solid-run.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2026-05-15 07:29:16 +02:00
Jason Gunthorpe
b948a87228 iommu: Fix up map/unmap debugging for iommupt domains
Sashiko noticed a few issues in this path, and a few more were
found on review. Tidy them up further. These are intertwined
because the debug code depends on some of the WARN_ONs to function
right:

Lift into iommu_map_nosync():
- The might_sleep_if()
- 0 pgsize_bitmap WARN_ON
- Promote the illegal domain->type to a WARN_ON
- WARN_ON for illegal gfp flags

Then remove the return 0 since it is now safe to call
iommu_debug_map().

Lift into __iommu_unmap():
- 0 pgsize_bitmap WARN_ON
- Promote the illegal domain->type to a WARN_ON
- iommu_debug_unmap_begin()

This now pairs with the unconditional iommu_debug_map() on the
mapping side. Thus iommu debugging now works for iommupt along
with some of the other debugging features.

Fixes: 99fb8afa16 ("iommupt: Directly call iommupt's unmap_range()")
Fixes: d6c65b0fd6 ("iommupt: Avoid rewalking during map")
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Pranjal Shrivastava <praan@google.com>
Reviewed-by: Samiullah Khawaja <skhawaja@google.com>
Reviewed-by: Mostafa Saleh <smostafa@google.com>
Tested-by: Josua Mayer <josua@solid-run.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2026-05-15 07:29:15 +02:00
Jason Gunthorpe
6fc7e8a3b8 iommu: Fix loss of errno on map failure for classic ops
A typo, likely from a rebase, inverted the condition and caused
errors to be lost. Fix it to be "if (ret)".

This was breaking iommu_create_device_direct_mappings() on drivers
that don't use iommupt and don't fully set up their domain in
alloc_pages() (i.e., SMMUv2). In this case the first call of
iommu_create_device_direct_mappings() should fail due to the
incompletely initialized domain. Since it wrongly returns success,
the second call to iommu_create_device_direct_mappings() doesn't
happen and IOMMU_RESV_DIRECT is never set up.

Cc: stable@vger.kernel.org
Fixes: d6c65b0fd6 ("iommupt: Avoid rewalking during map")
Reported-by: Josua Mayer <josua@solid-run.com>
Closes: https://lore.kernel.org/all/321c2e57-6a17-4aef-ba42-d2ebd577e472@solid-run.com/
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Pranjal Shrivastava <praan@google.com>
Reviewed-by: Samiullah Khawaja <skhawaja@google.com>
Reviewed-by: Mostafa Saleh <smostafa@google.com>
Tested-by: Josua Mayer <josua@solid-run.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2026-05-15 07:29:15 +02:00
Nicolin Chen
15dd29ca62 iommu: Warn on premature unblock during DMA aliased sibling reset
When two aliased siblings are in the same iommu_group, they might share the
same RID. The reset functions don't support this case, though it is unclear
whether there is a real case of having an ATS capable device on a PCI/PCI-X
bus.

Theoretically, however, if two aliased devices are resetting concurrently,
one might be unblocked prematurely in the middle of the reset by the other
sibling who completes the reset first.

This isn't a regression from this series but it's better to spit a warning,
so we can know if such use case is common enough for us to make subsequent
patches for its coverage.

Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2026-05-11 10:12:45 +02:00
Nicolin Chen
5474e6e17a iommu: Fix WARN_ON in __iommu_group_set_domain_nofail() due to reset
In __iommu_group_set_domain_internal(), concurrent domain attachments are
rejected when any device in the group is recovering. This is necessary to
fence concurrent attachments to a multi-device group where devices might
share the same RID due to PCI DMA alias quirks, but triggers the WARN_ON in
__iommu_group_set_domain_nofail().

Other IOMMU_SET_DOMAIN_MUST_SUCCEED callers in detach/teardown paths, such
as __iommu_group_set_core_domain and __iommu_release_dma_ownership, should
not be rejected, as the domain would be freed anyway in these nofail paths
while group->domain is still pointing to it. So pci_dev_reset_iommu_done()
could trigger a UAF when re-attaching group->domain.

Honor the IOMMU_SET_DOMAIN_MUST_SUCCEED flag, allowing the callers through
the group->recovery_cnt fence, so as to update the group->domain pointer.
Instead add a gdev->blocked check in the device iteration loop, to prevent
any concurrent per-device detachment.

Fixes: c279e83953 ("iommu: Introduce pci_dev_reset_iommu_prepare/done()")
Cc: stable@vger.kernel.org
Closes: https://sashiko.dev/#/patchset/20260407194644.171304-1-nicolinc%40nvidia.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: Joerg Roedel <joerg.roedel@amd.com>
2026-05-11 10:12:44 +02:00
Nicolin Chen
fc3523b16d iommu: Fix ATS invalidation timeouts during __iommu_remove_group_pasid()
If a device is blocked, its PASID domains are already detached. Repeating
iommu_remove_dev_pasid() is unnecessary and might trigger ATS invalidation
timeouts.

Skip the iommu_remove_dev_pasid() call upon gdev->blocked.

Fixes: c279e83953 ("iommu: Introduce pci_dev_reset_iommu_prepare/done()")
Cc: stable@vger.kernel.org
Closes: https://sashiko.dev/#/patchset/20260407194644.171304-1-nicolinc%40nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2026-05-11 10:12:44 +02:00
Nicolin Chen
0d5fd7a932 iommu: Fix nested pci_dev_reset_iommu_prepare/done()
Shuai found that cxl_reset_bus_function() calls pci_reset_bus_function()
internally while both are calling pci_dev_reset_iommu_prepare/done().

As pci_dev_reset_iommu_prepare() doesn't support re-entry, the inner call
will trigger a WARN_ON and return -EBUSY, resulting in failing the entire
device reset.

On the other hand, removing the outer calls in the PCI callers is unsafe.
As pointed out by Kevin, device-specific quirks like reset_hinic_vf_dev()
execute custom firmware waits after their inner pcie_flr() completes. If
the IOMMU protection relies solely on the inner reset, the IOMMU will be
unblocked prematurely while the device is still resetting.

Instead, fix this by making pci_dev_reset_iommu_prepare/done() reentrant.

Introduce gdev->reset_depth to handle the re-entries on the same device.

Fixes: c279e83953 ("iommu: Introduce pci_dev_reset_iommu_prepare/done()")
Cc: stable@vger.kernel.org
Reported-by: Shuai Xue <xueshuai@linux.alibaba.com>
Closes: https://lore.kernel.org/all/absKsk7qQOwzhpzv@Asurada-Nvidia/
Suggested-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Shuai Xue <xueshuai@linux.alibaba.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: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2026-05-11 10:12:44 +02:00
Nicolin Chen
1615e8896a iommu: Fix pasid attach in pci_dev_reset_iommu_prepare/done()
Now the helpers handle per-gdev resets. Replace __iommu_set_group_pasid()
with set_dev_pasid() accordingly, in the pci_dev_reset_iommu_done().

Also add max_pasids check as other callers.

Fixes: c279e83953 ("iommu: Introduce pci_dev_reset_iommu_prepare/done()")
Cc: stable@vger.kernel.org
Reported-by: Shuai Xue <xueshuai@linux.alibaba.com>
Closes: https://lore.kernel.org/all/ad858513-09fc-455e-bbc5-fe38a225cc78@linux.alibaba.com/
Reviewed-by: Shuai Xue <xueshuai@linux.alibaba.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2026-05-11 10:12:44 +02:00
Nicolin Chen
b296ca1fb4 iommu: Replace per-group resetting_domain with per-gdev blocked flag
The core tracks device resetting states with a per-group resetting_domain,
while a reset is actually per group-device. Such a mismatch might lead to
confusion and even difficulty to untangle per-gdev handling requirement.

Shuai found that cxl_reset_bus_function() calls pci_reset_bus_function()
internally while both are calling pci_dev_reset_iommu_prepare/done(). And
the solution requires the core to track at the group_device level as well.

Introduce a 'blocked' flag to struct group_device, to allow a multi-device
group to isolate concurrent device resets independently.

As the reset routine is per gdev, it cannot clear group->resetting_domain
without iterating over the device list to ensure no other device is being
reset. Simplify it by replacing the resetting_domain with a 'recovery_cnt'
in the struct iommu_group.

No functional change. But this is essential to apply following bug fixes.

Fixes: c279e83953 ("iommu: Introduce pci_dev_reset_iommu_prepare/done()")
Cc: stable@vger.kernel.org
Reported-by: Shuai Xue <xueshuai@linux.alibaba.com>
Closes: https://lore.kernel.org/all/absKsk7qQOwzhpzv@Asurada-Nvidia/
Reviewed-by: Shuai Xue <xueshuai@linux.alibaba.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: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2026-05-11 10:12:43 +02:00
Nicolin Chen
834ab85aa9 iommu: Fix kdocs of pci_dev_reset_iommu_done()
Remove the duplicated word. No functional change.

Fixes: c279e83953 ("iommu: Introduce pci_dev_reset_iommu_prepare/done()")
Reviewed-by: Shuai Xue <xueshuai@linux.alibaba.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: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2026-05-11 10:12:43 +02:00
Nicolin Chen
d769711fcd iommu: Fix NULL group->domain dereference in pci_dev_reset_iommu_done()
Local sashiko review pointed it out that group->domain could be NULL when
a default domain fails to allocate during the first probe, which can crash
at domain->ops->attach_dev dereference in __iommu_attach_device() invoked
by pci_dev_reset_iommu_done().

pci_dev_reset_iommu_prepare() is fine as an old_domain pointer can be NULL.

Skip the re-attach in pci_dev_reset_iommu_done() to fix the bug.

Fixes: c279e83953 ("iommu: Introduce pci_dev_reset_iommu_prepare/done()")
Cc: stable@vger.kernel.org
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2026-05-11 10:12:43 +02:00
Will Deacon
f8d5e7066d Merge branches 'fixes', 'arm/smmu/updates', 'arm/smmu/bindings', 'riscv', 'intel/vt-d', 'amd/amd-vi' and 'core' into next 2026-04-09 13:18:27 +01:00
Robin Murphy
7e0548525a iommu: Ensure .iotlb_sync is called correctly
Many drivers have no reason to use the iotlb_gather mechanism, but do
still depend on .iotlb_sync being called to properly complete an unmap.
Since the core code is now relying on the gather to detect when there
is legitimately something to sync, it should also take care of encoding
a successful unmap when the driver does not touch the gather itself.

Fixes: 90c5def10b ("iommu: Do not call drivers for empty gathers")
Reported-by: Jon Hunter <jonathanh@nvidia.com>
Closes: https://lore.kernel.org/r/8800a38b-8515-4bbe-af15-0dae81274bf7@nvidia.com
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Tested-by: Jon Hunter <jonathanh@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Tested-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Will Deacon <will@kernel.org>
2026-04-09 13:07:13 +01:00
Jason Gunthorpe
d6c65b0fd6 iommupt: Avoid rewalking during map
Currently the core code provides a simplified interface to drivers where
it fragments a requested multi-page map into single page size steps after
doing all the calculations to figure out what page size is
appropriate. Each step rewalks the page tables from the start.

Since iommupt has a single implementation of the mapping algorithm it can
internally compute each step as it goes while retaining its current
position in the walk.

Add a new function pt_pgsz_count() which computes the same page size
fragement of a large mapping operations.

Compute the next fragment when all the leaf entries of the current
fragement have been written, then continue walking from the current
point.

The function pointer is run through pt_iommu_ops instead of
iommu_domain_ops to discourage using it outside iommupt. All drivers with
their own page tables should continue to use the simplified map_pages()
style interfaces.

Reviewed-by: Samiullah Khawaja <skhawaja@google.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2026-03-17 13:57:40 +01:00
Jason Gunthorpe
99fb8afa16 iommupt: Directly call iommupt's unmap_range()
The common algorithm in iommupt does not require the iommu_pgsize()
calculations, it can directly unmap any arbitrary range. Add a new function
pointer to directly call an iommupt unmap_range op and make
__iommu_unmap() call it directly.

Gives about a 5% gain on single page unmappings.

The function pointer is run through pt_iommu_ops instead of
iommu_domain_ops to discourage using it outside iommupt. All drivers with
their own page tables should continue to use the simplified
map/unmap_pages() style interfaces.

Reviewed-by: Samiullah Khawaja <skhawaja@google.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2026-03-17 13:57:39 +01:00
Antheas Kapenekakis
0a4d00e2e9 iommu: Fix mapping check for 0x0 to avoid re-mapping it
Commit 789a5913b2 ("iommu/amd: Use the generic iommu page table")
introduces the shared iommu page table for AMD IOMMU. Some bioses
contain an identity mapping for address 0x0, which is not parsed
properly (e.g., certain Strix Halo devices). This causes the DMA
components of the device to fail to initialize (e.g., the NVMe SSD
controller), leading to a failed post.

Specifically, on the GPD Win 5, the NVME and SSD GPU fail to mount,
making collecting errors difficult. While debugging, it was found that
a -EADDRINUSE error was emitted and its source was traced to
iommu_iova_to_phys(). After adding some debug prints, it was found that
phys_addr becomes 0, which causes the code to try to re-map the 0
address and fail, causing a cascade leading to a failed post. This is
because the GPD Win 5 contains a 0x0-0x1 identity mapping for DMA
devices, causing it to be repeated for each device.

The cause of this failure is the following check in
iommu_create_device_direct_mappings(), where address aliasing is handled
via the following check:

```
phys_addr = iommu_iova_to_phys(domain, addr);
if (!phys_addr) {
        map_size += pg_size;
        continue;
}
````

Obviously, the iommu_iova_to_phys() signature is faulty and aliases
unmapped and 0 together, causing the allocation code to try to
re-allocate the 0 address per device. However, it has too many
instantiations to fix. Therefore, use a ternary so that when addr
is 0, the check is done for address 1 instead.

Suggested-by: Robin Murphy <robin.murphy@arm.com>
Fixes: 789a5913b2 ("iommu/amd: Use the generic iommu page table")
Signed-off-by: Antheas Kapenekakis <lkml@antheas.dev>
Reviewed-by: Vasant Hegde <vasant.hegde@amd.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2026-03-17 13:33:33 +01:00
Linus Torvalds
323bbfcf1e Convert 'alloc_flex' family to use the new default GFP_KERNEL argument
This is the exact same thing as the 'alloc_obj()' version, only much
smaller because there are a lot fewer users of the *alloc_flex()
interface.

As with alloc_obj() version, this was done entirely with mindless brute
force, using the same script, except using 'flex' in the pattern rather
than 'objs*'.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2026-02-21 17:09:51 -08:00
Linus Torvalds
bf4afc53b7 Convert 'alloc_obj' family to use the new default GFP_KERNEL argument
This was done entirely with mindless brute force, using

    git grep -l '\<k[vmz]*alloc_objs*(.*, GFP_KERNEL)' |
        xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/'

to convert the new alloc_obj() users that had a simple GFP_KERNEL
argument to just drop that argument.

Note that due to the extreme simplicity of the scripting, any slightly
more complex cases spread over multiple lines would not be triggered:
they definitely exist, but this covers the vast bulk of the cases, and
the resulting diff is also then easier to check automatically.

For the same reason the 'flex' versions will be done as a separate
conversion.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2026-02-21 17:09:51 -08:00
Kees Cook
69050f8d6d treewide: Replace kmalloc with kmalloc_obj for non-scalar types
This is the result of running the Coccinelle script from
scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to
avoid scalar types (which need careful case-by-case checking), and
instead replace kmalloc-family calls that allocate struct or union
object instances:

Single allocations:	kmalloc(sizeof(TYPE), ...)
are replaced with:	kmalloc_obj(TYPE, ...)

Array allocations:	kmalloc_array(COUNT, sizeof(TYPE), ...)
are replaced with:	kmalloc_objs(TYPE, COUNT, ...)

Flex array allocations:	kmalloc(struct_size(PTR, FAM, COUNT), ...)
are replaced with:	kmalloc_flex(*PTR, FAM, COUNT, ...)

(where TYPE may also be *VAR)

The resulting allocations no longer return "void *", instead returning
"TYPE *".

Signed-off-by: Kees Cook <kees@kernel.org>
2026-02-21 01:02:28 -08:00
Can Peng
16e3423fc7 iommu: simplify list initialization in iommu_create_device_direct_mappings()
Use LIST_HEAD() to declare and initialize the 'mappings' list head in
iommu_create_device_direct_mappings() instead of separate declaration and
INIT_LIST_HEAD(). This simplifies the code by combining declaration and
initialization into a single idiomatic form, improving readability without
changing functionality.

Signed-off-by: Can Peng <pengcan@kylinos.cn>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2026-01-10 10:58:54 +01:00
Mostafa Saleh
ccc21213f0 iommu: Add calls for IOMMU_DEBUG_PAGEALLOC
Add calls for the new iommu debug config IOMMU_DEBUG_PAGEALLOC:
- iommu_debug_init: Enable the debug mode if configured by the user.
- iommu_debug_map: Track iommu pages mapped, using physical address.
- iommu_debug_unmap_begin: Track start of iommu unmap operation, with
  IOVA and size.
- iommu_debug_unmap_end: Track the end of unmap operation, passing the
  actual unmapped size versus the tracked one at unmap_begin.

We have to do the unmap_begin/end as once pages are unmapped we lose
the information of the physical address.
This is racy, but the API is racy by construction as it uses refcounts
and doesn't attempt to lock/synchronize with the IOMMU API as that will
be costly, meaning that possibility of false negative exists.

Reviewed-by: Samiullah Khawaja <skhawaja@google.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Pranjal Shrivastava <praan@google.com>
Signed-off-by: Mostafa Saleh <smostafa@google.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2026-01-10 10:52:26 +01:00
Nicolin Chen
c279e83953 iommu: Introduce pci_dev_reset_iommu_prepare/done()
PCIe permits a device to ignore ATS invalidation TLPs while processing a
reset. This creates a problem visible to the OS where an ATS invalidation
command will time out. E.g. an SVA domain will have no coordination with a
reset event and can racily issue ATS invalidations to a resetting device.

The OS should do something to mitigate this as we do not want production
systems to be reporting critical ATS failures, especially in a hypervisor
environment. Broadly, OS could arrange to ignore the timeouts, block page
table mutations to prevent invalidations, or disable and block ATS.

The PCIe r6.0, sec 10.3.1 IMPLEMENTATION NOTE recommends SW to disable and
block ATS before initiating a Function Level Reset. It also mentions that
other reset methods could have the same vulnerability as well.

Provide a callback from the PCI subsystem that will enclose the reset and
have the iommu core temporarily change all the attached RID/PASID domains
group->blocking_domain so that the IOMMU hardware would fence any incoming
ATS queries. And IOMMU drivers should also synchronously stop issuing new
ATS invalidations and wait for all ATS invalidations to complete. This can
avoid any ATS invaliation timeouts.

However, if there is a domain attachment/replacement happening during an
ongoing reset, ATS routines may be re-activated between the two function
calls. So, introduce a new resetting_domain in the iommu_group structure
to reject any concurrent attach_dev/set_dev_pasid call during a reset for
a concern of compatibility failure. Since this changes the behavior of an
attach operation, update the uAPI accordingly.

Note that there are two corner cases:
 1. Devices in the same iommu_group
    Since an attachment is always per iommu_group, this means that any
    sibling devices in the iommu_group cannot change domain, to prevent
    race conditions.
 2. An SR-IOV PF that is being reset while its VF is not
    In such case, the VF itself is already broken. So, there is no point
    in preventing PF from going through the iommu reset.

Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Tested-by: Dheeraj Kumar Srivastava <dheerajkumar.srivastava@amd.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2026-01-10 10:26:44 +01:00
Nicolin Chen
a75b2be249 iommu: Add iommu_driver_get_domain_for_dev() helper
There is a need to stage a resetting PCI device to temporarily the blocked
domain and then attach back to its previously attached domain after reset.

This can be simply done by keeping the "previously attached domain" in the
iommu_group->domain pointer while adding an iommu_group->resetting_domain,
which gives troubles to IOMMU drivers using the iommu_get_domain_for_dev()
for a device's physical domain in order to program IOMMU hardware.

And in such for-driver use cases, the iommu_group->mutex must be held, so
it doesn't fit in external callers that don't hold the iommu_group->mutex.

Introduce a new iommu_driver_get_domain_for_dev() helper, exclusively for
driver use cases that hold the iommu_group->mutex, to separate from those
external use cases.

Add a lockdep_assert_not_held to the existing iommu_get_domain_for_dev()
and highlight that in a kdoc.

Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Tested-by: Dheeraj Kumar Srivastava <dheerajkumar.srivastava@amd.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2026-01-10 10:26:43 +01:00
Nicolin Chen
4a73abb965 iommu: Tidy domain for iommu_setup_dma_ops()
This function can only be called on the default_domain. Trivally pass it
in. In all three existing cases, the default domain was just attached to
the device.

This avoids iommu_setup_dma_ops() calling iommu_get_domain_for_dev() that
will be used by external callers.

Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Tested-by: Dheeraj Kumar Srivastava <dheerajkumar.srivastava@amd.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2026-01-10 10:26:43 +01:00
Nicolin Chen
5d5388b0e1 iommu: Lock group->mutex in iommu_deferred_attach()
The iommu_deferred_attach() function invokes __iommu_attach_device(), but
doesn't hold the group->mutex like other __iommu_attach_device() callers.

Though there is no pratical bug being triggered so far, it would be better
to apply the same locking to this __iommu_attach_device(), since the IOMMU
drivers nowaday are more aware of the group->mutex -- some of them use the
iommu_group_mutex_assert() function that could be potentially in the path
of an attach_dev callback function invoked by the __iommu_attach_device().

Worth mentioning that the iommu_deferred_attach() will soon need to check
group->resetting_domain that must be locked also.

Thus, grab the mutex to guard __iommu_attach_device() like other callers.

Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Tested-by: Dheeraj Kumar Srivastava <dheerajkumar.srivastava@amd.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Samiullah Khawaja <skhawaja@google.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2026-01-10 10:26:42 +01:00
Nicolin Chen
fd714986e4 iommu: Pass in old domain to attach_dev callback functions
The IOMMU core attaches each device to a default domain on probe(). Then,
every new "attach" operation has a fundamental meaning of two-fold:
 - detach from its currently attached (old) domain
 - attach to a given new domain

Modern IOMMU drivers following this pattern usually want to clean up the
things related to the old domain, so they call iommu_get_domain_for_dev()
to fetch the old domain.

Pass in the old domain pointer from the core to drivers, aligning with the
set_dev_pasid op that does so already.

Ensure all low-level attach fcuntions in the core can forward the correct
old domain pointer. Thus, rework those functions as well.

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>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2025-10-27 13:55:35 +01:00
Nicolin Chen
2b33598e66 iommu: Do not revert set_domain for the last gdev
The last gdev is the device that failed the __iommu_device_set_domain().
So, it doesn't need to be reverted, given it's attached to group->domain
already.

This is not a problem currently, since it's a simply re-attach. However,
the core will need to pass in the old domain to __iommu_device_set_domain
so the old domain pointers would be inconsistent between a failed device
and all its prior succeeded devices, as all the prior devices need to be
reverted.

Avoid the re-attach for the last gdev, by breaking before the revert.

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: Joerg Roedel <joerg.roedel@amd.com>
2025-10-27 13:55:35 +01:00
Jason Gunthorpe
e94160488e iommu: Generic support for RMRs during device release
Generally an IOMMU driver should leave the translation as BLOCKED until the
translation entry is probed onto a struct device. When the struct device is
removed, the translation should be put back to BLOCKED.

Drivers that are able to work like this can set their release_domain to the
blocking domain, and the core code handles this work.

The exception is when the device has an IOMMU_RESV_DIRECT region, in which
case the OS should continuously allow translations for the given range. And
the core code generally prevents using a BLOCKED domain with this device.

Continue this logic for the device release and hoist some open coding from
drivers. If the device has dev->iommu->require_direct and the driver uses a
BLOCKED release_domain, override it to IDENTITY to preserve the semantics.

The only remaining required driver code for IOMMU_RESV_DIRECT should preset
an IDENTITY translation during early IOMMU startup for those devices.

Signed-off-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: Joerg Roedel <joerg.roedel@amd.com>
2025-10-27 13:55:34 +01:00
Guixin Liu
2a918911ed iommufd: Register iommufd mock devices with fwspec
Since the bus ops were retired the iommu subsystem changed to using fwspec
to match the iommu driver to the iommu device. If a device has a NULL
fwspec then it is matched to the first iommu driver with a NULL fwspec,
effectively disabling support for systems with more than one non-fwspec
iommu driver.

Thus, if the iommufd selfest are run in an x86 system that registers a
non-fwspec iommu driver they fail to bind their mock devices to the mock
iommu driver.

Fix this by allocating a software fwnode for mock iommu driver's
iommu_device, and set it to the device which mock iommu driver created.

This is done by adding a new helper iommu_mock_device_add() which abuses
the internals of the fwspec system to establish a fwspec before the device
is added and is careful not to leak it. A matching dummy fwspec is
automatically added to the mock iommu driver.

Test by "make -C toosl/testing/selftests TARGETS=iommu run_tests":
PASSED: 229 / 229 tests passed.

In addition, this issue is also can be found on amd platform, and
also tested on a amd machine.

Link: https://patch.msgid.link/r/20250925054730.3877-1-kanie@linux.alibaba.com
Fixes: 17de3f5fdd ("iommu: Retire bus ops")
Signed-off-by: Guixin Liu <kanie@linux.alibaba.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Tested-by: Qinyun Tan <qinyuntan@linux.alibaba.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2025-09-30 09:54:12 -03:00
Jason Gunthorpe
792ea7b6ca iommu: Remove ops->pgsize_bitmap
No driver uses it now, remove the core code.

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>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Link: https://lore.kernel.org/r/7-v2-68a2e1ba507c+1fb-iommu_rm_ops_pgsize_jgg@nvidia.com
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2025-06-27 17:34:11 +02:00
Linus Torvalds
8477ab1430 IOMMU Updates for Linux v6.16:
Including:
 
 	- Core:
 	  - Introduction of iommu-pages infrastructure to consolitate page-table
 	    allocation code among hardware drivers. This is ground-work for more
 	    generalization in the future.
 	  - Remove IOMMU_DEV_FEAT_SVA and IOMMU_DEV_FEAT_IOPF feature flags.
 	  - Convert virtio-iommu to domain_alloc_paging().
 	  - KConfig cleanups.
 	  - Some small fixes for possible overflows and race conditions.
 
 	- Intel VT-d driver:
 	   - Restore WO permissions on second-level paging entries.
 	   - Use ida to manage domain id.
 	   - Miscellaneous cleanups.
 
 	- AMD-Vi:
 	  - Make sure notifiers finish running before module unload.
 	  - Add support for HTRangeIgnore feature.
 	  - Allow matching ACPI HID devices without matching UIDs.
 
 	- ARM-SMMU:
 	  - SMMUv2:
 	    - Recognise the compatible string for SAR2130P MDSS in the Qualcomm
 	      driver, as this device requires an identity domain.
 	    - Fix Adreno stall handling so that GPU debugging is more robust and
 	      doesn't e.g. result in deadlock.
 	  - SMMUv3:
 	    - Fix ->attach_dev() error reporting for unrecognised domains.
 	  - IO-pgtable:
 	    - Allow clients (notably, drivers that process requests from
 	      userspace) to silence warnings when mapping an already-mapped IOVA.
 
 	- S390:
 	  - Add support for additional table regions.
 
 	- Mediatek:
 	  - Add support for MT6893 MM IOMMU.
 
 	- Some smaller fixes and improvements in various other drivers.
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Merge tag 'iommu-updates-v6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/iommu/linux

Pull iommu updates from Joerg Roedel:
 "Core:
   - Introduction of iommu-pages infrastructure to consolitate
     page-table allocation code among hardware drivers. This is
     ground-work for more generalization in the future
   - Remove IOMMU_DEV_FEAT_SVA and IOMMU_DEV_FEAT_IOPF feature flags
   - Convert virtio-iommu to domain_alloc_paging()
   - KConfig cleanups
   - Some small fixes for possible overflows and race conditions

  Intel VT-d driver:
   - Restore WO permissions on second-level paging entries
   - Use ida to manage domain id
   - Miscellaneous cleanups

  AMD-Vi:
   - Make sure notifiers finish running before module unload
   - Add support for HTRangeIgnore feature
   - Allow matching ACPI HID devices without matching UIDs

  ARM-SMMU:
   - SMMUv2:
      - Recognise the compatible string for SAR2130P MDSS in the
        Qualcomm driver, as this device requires an identity domain
      - Fix Adreno stall handling so that GPU debugging is more robust
        and doesn't e.g. result in deadlock
   - SMMUv3:
      - Fix ->attach_dev() error reporting for unrecognised domains
   - IO-pgtable:
      - Allow clients (notably, drivers that process requests from
        userspace) to silence warnings when mapping an already-mapped
        IOVA

  S390:
   - Add support for additional table regions

  Mediatek:
   - Add support for MT6893 MM IOMMU

  And some smaller fixes and improvements in various other drivers"

* tag 'iommu-updates-v6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/iommu/linux: (75 commits)
  iommu/vt-d: Restore context entry setup order for aliased devices
  iommu/mediatek: Fix compatible typo for mediatek,mt6893-iommu-mm
  iommu/arm-smmu-qcom: Make set_stall work when the device is on
  iommu/arm-smmu: Move handing of RESUME to the context fault handler
  iommu/arm-smmu-qcom: Enable threaded IRQ for Adreno SMMUv2/MMU500
  iommu/io-pgtable-arm: Add quirk to quiet WARN_ON()
  iommu: Clear the freelist after iommu_put_pages_list()
  iommu/vt-d: Change dmar_ats_supported() to return boolean
  iommu/vt-d: Eliminate pci_physfn() in dmar_find_matched_satc_unit()
  iommu/vt-d: Replace spin_lock with mutex to protect domain ida
  iommu/vt-d: Use ida to manage domain id
  iommu/vt-d: Restore WO permissions on second-level paging entries
  iommu/amd: Allow matching ACPI HID devices without matching UIDs
  iommu: make inclusion of arm/arm-smmu-v3 directory conditional
  iommu: make inclusion of riscv directory conditional
  iommu: make inclusion of amd directory conditional
  iommu: make inclusion of intel directory conditional
  iommu: remove duplicate selection of DMAR_TABLE
  iommu/fsl_pamu: remove trailing space after \n
  iommu/arm-smmu-qcom: Add SAR2130P MDSS compatible
  ...
2025-05-30 10:44:20 -07:00
Linus Torvalds
23022f5456 dma-mapping updates for Linux 6.16:
- new two step DMA mapping API, which is is a first step to a long path
   to provide alternatives to scatterlist and to remove hacks, abuses and
   design mistakes related to scatterlists; this new approach optimizes
   some calls to DMA-IOMMU layer and cache maintenance by batching them,
   reduces memory usage as it is no need to store mapped DMA addresses to
   unmap them, and reduces some function call overhead; it is a combination
   effort of many people, lead and developed by Christoph Hellwig and Leon
   Romanovsky
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Merge tag 'dma-mapping-6.16-2025-05-26' of git://git.kernel.org/pub/scm/linux/kernel/git/mszyprowski/linux

Pull dma-mapping updates from Marek Szyprowski:
 "New two step DMA mapping API, which is is a first step to a long path
  to provide alternatives to scatterlist and to remove hacks, abuses and
  design mistakes related to scatterlists.

  This new approach optimizes some calls to DMA-IOMMU layer and cache
  maintenance by batching them, reduces memory usage as it is no need to
  store mapped DMA addresses to unmap them, and reduces some function
  call overhead.  It is a combination effort of many people, lead and
  developed by Christoph Hellwig and Leon Romanovsky"

* tag 'dma-mapping-6.16-2025-05-26' of git://git.kernel.org/pub/scm/linux/kernel/git/mszyprowski/linux:
  docs: core-api: document the IOVA-based API
  dma-mapping: add a dma_need_unmap helper
  dma-mapping: Implement link/unlink ranges API
  iommu/dma: Factor out a iommu_dma_map_swiotlb helper
  dma-mapping: Provide an interface to allow allocate IOVA
  iommu: add kernel-doc for iommu_unmap_fast
  iommu: generalize the batched sync after map interface
  dma-mapping: move the PCI P2PDMA mapping helpers to pci-p2pdma.h
  PCI/P2PDMA: Refactor the p2pdma mapping helpers
2025-05-27 20:09:06 -07:00
Joerg Roedel
879b141b7c Merge branches 'fixes', 'apple/dart', 'arm/smmu/updates', 'arm/smmu/bindings', 'fsl/pamu', 'mediatek', 'renesas/ipmmu', 's390', 'intel/vt-d', 'amd/amd-vi' and 'core' into next 2025-05-23 17:14:32 +02:00
Tushar Dave
b3f6fcd840 iommu: Skip PASID validation for devices without PASID capability
Generally PASID support requires ACS settings that usually create
single device groups, but there are some niche cases where we can get
multi-device groups and still have working PASID support. The primary
issue is that PCI switches are not required to treat PASID tagged TLPs
specially so appropriate ACS settings are required to route all TLPs to
the host bridge if PASID is going to work properly.

pci_enable_pasid() does check that each device that will use PASID has
the proper ACS settings to achieve this routing.

However, no-PASID devices can be combined with PASID capable devices
within the same topology using non-uniform ACS settings. In this case
the no-PASID devices may not have strict route to host ACS flags and
end up being grouped with the PASID devices.

This configuration fails to allow use of the PASID within the iommu
core code which wrongly checks if the no-PASID device supports PASID.

Fix this by ignoring no-PASID devices during the PASID validation. They
will never issue a PASID TLP anyhow so they can be ignored.

Fixes: c404f55c26 ("iommu: Validate the PASID in iommu_attach_device_pasid()")
Cc: stable@vger.kernel.org
Signed-off-by: Tushar Dave <tdave@nvidia.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Vasant Hegde <vasant.hegde@amd.com>
Link: https://lore.kernel.org/r/20250520011937.3230557-1-tdave@nvidia.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2025-05-22 09:10:00 +02:00
Leon Romanovsky
dc2e692943 iommu: add kernel-doc for iommu_unmap_fast
Add kernel-doc section for iommu_unmap_fast to document existing
limitation of underlying functions which can't split individual ranges.

Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Acked-by: Will Deacon <will@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Tested-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
2025-05-06 08:36:53 +02:00
Christoph Hellwig
5c87cffe2d iommu: generalize the batched sync after map interface
For the upcoming IOVA-based DMA API we want to batch the
ops->iotlb_sync_map() call after mapping multiple IOVAs from
dma-iommu without having a scatterlist. Improve the API.

Add a wrapper for the map_sync as iommu_sync_map() so that callers
don't need to poke into the methods directly.

Formalize __iommu_map() into iommu_map_nosync() which requires the
caller to call iommu_sync_map() after all maps are completed.

Refactor the existing sanity checks from all the different layers
into iommu_map_nosync().

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Will Deacon <will@kernel.org>
Tested-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
2025-05-06 08:36:53 +02:00
Jason Gunthorpe
e586e22974 iommu: Protect against overflow in iommu_pgsize()
On a 32 bit system calling:
 iommu_map(0, 0x40000000)

When using the AMD V1 page table type with a domain->pgsize of 0xfffff000
causes iommu_pgsize() to miscalculate a result of:
  size=0x40000000 count=2

count should be 1. This completely corrupts the mapping process.

This is because the final test to adjust the pagesize malfunctions when
the addition overflows. Use check_add_overflow() to prevent this.

Fixes: b1d99dc5f9 ("iommu: Hook up '->unmap_pages' driver callback")
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/0-v1-3ad28fc2e3a3+163327-iommu_overflow_pgsize_jgg@nvidia.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2025-04-28 13:33:30 +02:00
Robin Murphy
da33e87bd2 iommu: Handle yet another race around registration
Next up on our list of race windows to close is another one during
iommu_device_register() - it's now OK again for multiple instances to
run their bus_iommu_probe() in parallel, but an iommu_probe_device() can
still also race against a running bus_iommu_probe(). As Johan has
managed to prove, this has now become a lot more visible on DT platforms
wth driver_async_probe where a client driver is attempting to probe in
parallel with its IOMMU driver - although commit b46064a188 ("iommu:
Handle race with default domain setup") resolves this from the client
driver's point of view, this isn't before of_iommu_configure() has had
the chance to attempt to "replay" a probe that the bus walk hasn't even
tried yet, and so still cause the out-of-order group allocation
behaviour that we're trying to clean up (and now warning about).

The most reliable thing to do here is to explicitly keep track of the
"iommu_device_register() is still running" state, so we can then
special-case the ops lookup for the replay path (based on dev->iommu
again) to let that think it's still waiting for the IOMMU driver to
appear at all. This still leaves the longstanding theoretical case of
iommu_bus_notifier() being triggered during bus_iommu_probe(), but it's
not so simple to defer a notifier, and nobody's ever reported that being
a visible issue, so let's quietly kick that can down the road for now...

Reported-by: Johan Hovold <johan@kernel.org>
Fixes: bcb81ac6ae ("iommu: Get DT/ACPI parsing into the proper probe path")
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/88d54c1b48fed8279aa47d30f3d75173685bb26a.1745516488.git.robin.murphy@arm.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2025-04-28 13:31:18 +02:00
Lu Baolu
6f7340120a iommu: Allow attaching static domains in iommu_attach_device_pasid()
The idxd driver attaches the default domain to a PASID of the device to
perform kernel DMA using that PASID. The domain is attached to the
device's PASID through iommu_attach_device_pasid(), which checks if the
domain->owner matches the iommu_ops retrieved from the device. If they
do not match, it returns a failure.

        if (ops != domain->owner || pasid == IOMMU_NO_PASID)
                return -EINVAL;

The static identity domain implemented by the intel iommu driver doesn't
specify the domain owner. Therefore, kernel DMA with PASID doesn't work
for the idxd driver if the device translation mode is set to passthrough.

Generally the owner field of static domains are not set because they are
already part of iommu ops. Add a helper domain_iommu_ops_compatible()
that checks if a domain is compatible with the device's iommu ops. This
helper explicitly allows the static blocked and identity domains associated
with the device's iommu_ops to be considered compatible.

Fixes: 2031c469f8 ("iommu/vt-d: Add support for static identity domain")
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=220031
Cc: stable@vger.kernel.org
Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/linux-iommu/20250422191554.GC1213339@ziepe.ca/
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Vasant Hegde <vasant.hegde@amd.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Link: https://lore.kernel.org/r/20250424034123.2311362-1-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2025-04-28 13:23:35 +02:00
Jason Gunthorpe
21c03574df iommu: Hide ops.domain_alloc behind CONFIG_FSL_PAMU
fsl_pamu is the last user of domain_alloc(), and it is using it to create
something weird that doesn't really fit into the iommu subsystem
architecture. It is a not a paging domain since it doesn't have any
map/unmap ops. It may be some special kind of identity domain.

For now just leave it as is. Wrap it's definition in CONFIG_FSL_PAMU to
discourage any new drivers from attempting to use it.

Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Link: https://lore.kernel.org/r/5-v4-ff5fb6b03bd1+288-iommu_virtio_domains_jgg@nvidia.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2025-04-28 13:14:59 +02:00
Jason Gunthorpe
07107e7444 iommu/virtio: Move to domain_alloc_paging()
virtio has the complication that it sometimes wants to return a paging
domain for IDENTITY which makes this conversion a little different than
other drivers.

Add a viommu_domain_alloc_paging() that combines viommu_domain_alloc() and
viommu_domain_finalise() to always return a fully initialized and
finalized paging domain.

Use viommu_domain_alloc_identity() to implement the special non-bypass
IDENTITY flow by calling viommu_domain_alloc_paging() then
viommu_domain_map_identity().

Remove support for deferred finalize and the vdomain->mutex.

Remove core support for domain_alloc() IDENTITY as virtio was the last
driver using it.

Reviewed-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Link: https://lore.kernel.org/r/3-v4-ff5fb6b03bd1+288-iommu_virtio_domains_jgg@nvidia.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2025-04-28 13:14:58 +02:00
Jason Gunthorpe
0d609a1450 iommu: Add domain_alloc_identity()
virtio-iommu has a mode where the IDENTITY domain is actually a paging
domain with an identity mapping covering some of the system address
space manually created.

To support this add a new domain_alloc_identity() op that accepts
the struct device so that virtio can allocate and fully finalize a
paging domain to return.

Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Link: https://lore.kernel.org/r/2-v4-ff5fb6b03bd1+288-iommu_virtio_domains_jgg@nvidia.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2025-04-28 13:14:57 +02:00
Lu Baolu
f984fb09e6 iommu: Remove iommu_dev_enable/disable_feature()
No external drivers use these interfaces anymore. Furthermore, no existing
iommu drivers implement anything in the callbacks. Remove them to avoid
dead code.

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>
Reviewed-by: Nicolin Chen <nicolinc@nvidia.com>
Link: https://lore.kernel.org/r/20250418080130.1844424-9-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2025-04-28 13:04:35 +02:00
Robin Murphy
0c8e9c148e iommu: Avoid introducing more races
Although the lock-juggling is only a temporary workaround, we don't want
it to make things avoidably worse. Jason was right to be nervous, since
bus_iommu_probe() doesn't care *which* IOMMU instance it's probing for,
so it probably is possible for one walk to finish a probe which a
different walk started, thus we do want to check for that.

Also there's no need to drop the lock just to have of_iommu_configure()
do nothing when a fwspec already exists; check that directly and avoid
opening a window at all in that (still somewhat likely) case.

Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/09d901ad11b3a410fbb6e27f7d04ad4609c3fe4a.1741706365.git.robin.murphy@arm.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2025-04-17 16:31:07 +02:00
Robin Murphy
280e5a3010 iommu: Clear iommu-dma ops on cleanup
If iommu_device_register() encounters an error, it can end up tearing
down already-configured groups and default domains, however this
currently still leaves devices hooked up to iommu-dma (and even
historically the behaviour in this area was at best inconsistent across
architectures/drivers...) Although in the case that an IOMMU is present
whose driver has failed to probe, users cannot necessarily expect DMA to
work anyway, it's still arguable that we should do our best to put
things back as if the IOMMU driver was never there at all, and certainly
the potential for crashing in iommu-dma itself is undesirable. Make sure
we clean up the dev->dma_iommu flag along with everything else.

Reported-by: Chen-Yu Tsai <wenst@chromium.org>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Closes: https://lore.kernel.org/all/CAGXv+5HJpTYmQ2h-GD7GjyeYT7bL9EBCvu0mz5LgpzJZtzfW0w@mail.gmail.com/
Tested-by: Chen-Yu Tsai <wenst@chromium.org>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/e788aa927f6d827dd4ea1ed608fada79f2bab030.1744284228.git.robin.murphy@arm.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2025-04-11 09:15:59 +02:00
Fedor Pchelkin
df4bf3fa1b iommu: Fix crash in report_iommu_fault()
The following crash is observed while handling an IOMMU fault with a
recent kernel:

kernel tried to execute NX-protected page - exploit attempt? (uid: 0)
BUG: unable to handle page fault for address: ffff8c708299f700
PGD 19ee01067 P4D 19ee01067 PUD 101c10063 PMD 80000001028001e3
Oops: Oops: 0011 [#1] SMP NOPTI
CPU: 4 UID: 0 PID: 139 Comm: irq/25-AMD-Vi Not tainted 6.15.0-rc1+ #20 PREEMPT(lazy)
Hardware name: LENOVO 21D0/LNVNB161216, BIOS J6CN50WW 09/27/2024
RIP: 0010:0xffff8c708299f700
Call Trace:
 <TASK>
 ? report_iommu_fault+0x78/0xd3
 ? amd_iommu_report_page_fault+0x91/0x150
 ? amd_iommu_int_thread+0x77/0x180
 ? __pfx_irq_thread_fn+0x10/0x10
 ? irq_thread_fn+0x23/0x60
 ? irq_thread+0xf9/0x1e0
 ? __pfx_irq_thread_dtor+0x10/0x10
 ? __pfx_irq_thread+0x10/0x10
 ? kthread+0xfc/0x240
 ? __pfx_kthread+0x10/0x10
 ? ret_from_fork+0x34/0x50
 ? __pfx_kthread+0x10/0x10
 ? ret_from_fork_asm+0x1a/0x30
 </TASK>

report_iommu_fault() checks for an installed handler comparing the
corresponding field to NULL. It can (and could before) be called for a
domain with a different cookie type - IOMMU_COOKIE_DMA_IOVA, specifically.
Cookie is represented as a union so we may end up with a garbage value
treated there if this happens for a domain with another cookie type.

Formerly there were two exclusive cookie types in the union.
IOMMU_DOMAIN_SVA has a dedicated iommu_report_device_fault().

Call the fault handler only if the passed domain has a required cookie
type.

Found by Linux Verification Center (linuxtesting.org).

Fixes: 6aa63a4ec9 ("iommu: Sort out domain user data")
Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20250408213342.285955-1-pchelkin@ispras.ru
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2025-04-11 09:03:44 +02:00
Linus Torvalds
48552153cf iommufd 6.15 merge window pull
Two significant new items:
 
 - Allow reporting IOMMU HW events to userspace when the events are clearly
   linked to a device. This is linked to the VIOMMU object and is intended to
   be used by a VMM to forward HW events to the virtual machine as part of
   emulating a vIOMMU. ARM SMMUv3 is the first driver to use this
   mechanism. Like the existing fault events the data is delivered through
   a simple FD returning event records on read().
 
 - PASID support in VFIO. "Process Address Space ID" is a PCI feature that
   allows the device to tag all PCI DMA operations with an ID. The IOMMU
   will then use the ID to select a unique translation for those DMAs. This
   is part of Intel's vIOMMU support as VT-D HW requires the hypervisor to
   manage each PASID entry. The support is generic so any VFIO user could
   attach any translation to a PASID, and the support should work on ARM
   SMMUv3 as well. AMD requires additional driver work.
 
 Some minor updates, along with fixes:
 
 - Prevent using nested parents with fault's, no driver support today
 
 - Put a single "cookie_type" value in the iommu_domain to indicate what
   owns the various opaque owner fields
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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:
 "Two significant new items:

   - Allow reporting IOMMU HW events to userspace when the events are
     clearly linked to a device.

     This is linked to the VIOMMU object and is intended to be used by a
     VMM to forward HW events to the virtual machine as part of
     emulating a vIOMMU. ARM SMMUv3 is the first driver to use this
     mechanism. Like the existing fault events the data is delivered
     through a simple FD returning event records on read().

   - PASID support in VFIO.

     The "Process Address Space ID" is a PCI feature that allows the
     device to tag all PCI DMA operations with an ID. The IOMMU will
     then use the ID to select a unique translation for those DMAs. This
     is part of Intel's vIOMMU support as VT-D HW requires the
     hypervisor to manage each PASID entry.

     The support is generic so any VFIO user could attach any
     translation to a PASID, and the support should work on ARM SMMUv3
     as well. AMD requires additional driver work.

  Some minor updates, along with fixes:

   - Prevent using nested parents with fault's, no driver support today

   - Put a single "cookie_type" value in the iommu_domain to indicate
     what owns the various opaque owner fields"

* tag 'for-linus-iommufd' of git://git.kernel.org/pub/scm/linux/kernel/git/jgg/iommufd: (49 commits)
  iommufd: Test attach before detaching pasid
  iommufd: Fix iommu_vevent_header tables markup
  iommu: Convert unreachable() to BUG()
  iommufd: Balance veventq->num_events inc/dec
  iommufd: Initialize the flags of vevent in iommufd_viommu_report_event()
  iommufd/selftest: Add coverage for reporting max_pasid_log2 via IOMMU_HW_INFO
  iommufd: Extend IOMMU_GET_HW_INFO to report PASID capability
  vfio: VFIO_DEVICE_[AT|DE]TACH_IOMMUFD_PT support pasid
  vfio-iommufd: Support pasid [at|de]tach for physical VFIO devices
  ida: Add ida_find_first_range()
  iommufd/selftest: Add coverage for iommufd pasid attach/detach
  iommufd/selftest: Add test ops to test pasid attach/detach
  iommufd/selftest: Add a helper to get test device
  iommufd/selftest: Add set_dev_pasid in mock iommu
  iommufd: Allow allocating PASID-compatible domain
  iommu/vt-d: Add IOMMU_HWPT_ALLOC_PASID support
  iommufd: Enforce PASID-compatible domain for RID
  iommufd: Support pasid attach/replace
  iommufd: Enforce PASID-compatible domain in PASID path
  iommufd/device: Add pasid_attach array to track per-PASID attach
  ...
2025-04-01 18:03:46 -07:00
Yi Liu
8a9e1e773f iommu: Introduce a replace API for device pasid
Provide a high-level API to allow replacements of one domain with another
for specific pasid of a device. This is similar to
iommu_replace_group_handle() and it is expected to be used only by IOMMUFD.

Link: https://patch.msgid.link/r/20250321171940.7213-3-yi.l.liu@intel.com
Co-developed-by: Lu Baolu <baolu.lu@linux.intel.com>
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>
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 10:18:30 -03:00
Yi Liu
ada14b9f1a iommu: Require passing new handles to APIs supporting handle
Add kdoc to highligt the caller of iommu_[attach|replace]_group_handle()
and iommu_attach_device_pasid() should always provide a new handle. This
can avoid race with lockless reference to the handle. e.g. the
find_fault_handler() and iommu_report_device_fault() in the PRI path.

Link: https://patch.msgid.link/r/20250321171940.7213-2-yi.l.liu@intel.com
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Jason Gunthorpe <jgg@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 10:18:30 -03:00
Nicolin Chen
06d54f00f3 iommu: Drop sw_msi from iommu_domain
There are only two sw_msi implementations in the entire system, thus it's
not very necessary to have an sw_msi pointer.

Instead, check domain->cookie_type to call the two sw_msi implementations
directly from the core code.

Link: https://patch.msgid.link/r/7ded87c871afcbaac665b71354de0a335087bf0f.1742871535.git.nicolinc@nvidia.com
Suggested-by: Robin Murphy <robin.murphy@arm.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.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>
2025-03-25 10:18:19 -03:00