Commit Graph

6033 Commits

Author SHA1 Message Date
Linus Torvalds
aa7243aaf1 dma-mapping fixes for Linux 6.18
- two last minute fixes for the recently modified DMA API infrastructure:
 a proper handling of DMA_ATTR_MMIO in dma_iova_unlink() function (me) and
 a regression fix for the code refactoring related to P2PDMA (Pranjal
 Shrivastava)
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Merge tag 'dma-mapping-6.18-2025-11-27' of git://git.kernel.org/pub/scm/linux/kernel/git/mszyprowski/linux

Pull dma-mapping fixes from Marek Szyprowski:
 "Two last minute fixes for the recently modified DMA API infrastructure:

   - proper handling of DMA_ATTR_MMIO in dma_iova_unlink() function (me)

   - regression fix for the code refactoring related to P2PDMA (Pranjal
     Shrivastava)"

* tag 'dma-mapping-6.18-2025-11-27' of git://git.kernel.org/pub/scm/linux/kernel/git/mszyprowski/linux:
  dma-direct: Fix missing sg_dma_len assignment in P2PDMA bus mappings
  iommu/dma: add missing support for DMA_ATTR_MMIO for dma_iova_unlink()
2025-11-27 17:29:15 -08:00
Marek Szyprowski
1a96f3a22f iommu/dma: add missing support for DMA_ATTR_MMIO for dma_iova_unlink()
Commit c288d657dd added support for DMA_ATTR_MMIO attribute in the
dma_iova_link() code path, but missed that the CPU cache is being also
touched in the dma_iova_unlink() path. Fix this.

Fixes: c288d657dd ("iommu/dma: implement DMA_ATTR_MMIO for dma_iova_link().")
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Leon Romanovsky <leon@kernel.org>
Link: https://lore.kernel.org/r/20251124170955.3884351-1-m.szyprowski@samsung.com
2025-11-24 22:15:11 +01:00
Gustavo A. R. Silva
b07bf253ef iommufd/iommufd_private.h: Avoid -Wflex-array-member-not-at-end warning
-Wflex-array-member-not-at-end was introduced in GCC-14, and we are
getting ready to enable it, globally.

Move the conflicting declaration to the end of the corresponding
structure. Notice that struct iommufd_vevent is a flexible
structure, this is a structure that contains a flexible-array
member.

Fix the following warning:

drivers/iommu/iommufd/iommufd_private.h:621:31: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]

Link: https://patch.msgid.link/r/aRHOAwpATIE0oajj@kspp
Signed-off-by: "Gustavo A. R. Silva" <gustavoars@kernel.org>
Fixes: e36ba5ab80 ("iommufd: Add IOMMUFD_OBJ_VEVENTQ and IOMMUFD_CMD_VEVENTQ_ALLOC")
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2025-11-21 15:38:27 -04:00
Gustavo A. R. Silva
ac84ff4533 iommufd/driver: Fix counter initialization for counted_by annotation
One of the requirements for counted_by annotations is that the counter
member must be initialized before the first reference to the
flexible-array member.

Move the vevent->data_len = data_len; initialization to before the
first access to flexible array vevent->event_data.

Link: https://patch.msgid.link/r/aRL7ZFFqM5bRTd2D@kspp
Cc: stable@vger.kernel.org
Fixes: e8e1ef9b77 ("iommufd/viommu: Add iommufd_viommu_report_event helper")
Signed-off-by: "Gustavo A. R. Silva" <gustavoars@kernel.org>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2025-11-21 15:38:27 -04:00
Jason Gunthorpe
afb47765f9 iommufd: Make vfio_compat's unmap succeed if the range is already empty
iommufd returns ENOENT when attempting to unmap a range that is already
empty, while vfio type1 returns success. Fix vfio_compat to match.

Fixes: d624d6652a ("iommufd: vfio container FD ioctl compatibility")
Link: https://patch.msgid.link/r/0-v1-76be45eff0be+5d-iommufd_unmap_compat_jgg@nvidia.com
Reviewed-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Alex Mastro <amastro@fb.com>
Reported-by: Alex Mastro <amastro@fb.com>
Closes: https://lore.kernel.org/r/aP0S5ZF9l3sWkJ1G@devgpu012.nha5.facebook.com
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2025-11-05 15:11:26 -04:00
Jason Gunthorpe
cb30dfa75d iommufd: Don't overflow during division for dirty tracking
If pgshift is 63 then BITS_PER_TYPE(*bitmap->bitmap) * pgsize will overflow
to 0 and this triggers divide by 0.

In this case the index should just be 0, so reorganize things to divide
by shift and avoid hitting any overflows.

Link: https://patch.msgid.link/r/0-v1-663679b57226+172-iommufd_dirty_div0_jgg@nvidia.com
Cc: stable@vger.kernel.org
Fixes: 58ccf0190d ("vfio: Add an IOVA bitmap support")
Reviewed-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reported-by: syzbot+093a8a8b859472e6c257@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=093a8a8b859472e6c257
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2025-10-20 19:58:37 -03:00
Linus Torvalds
e56ebe27a0 iommufd 6.18 merge window pull
Two minor fixes
 
 - Make the selftest work again on x86 platforms with iommus enabled
 
 - Fix a compiler warning in the userspace kselftest
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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 minor fixes:

   - Make the selftest work again on x86 platforms with iommus enabled

   - Fix a compiler warning in the userspace kselftest"

* tag 'for-linus-iommufd' of git://git.kernel.org/pub/scm/linux/kernel/git/jgg/iommufd:
  iommufd: Register iommufd mock devices with fwspec
  iommu/selftest: prevent use of uninitialized variable
2025-10-03 18:18:48 -07:00
Linus Torvalds
bed0653fe2 IOMMU Updates for Linux v6.18:
Including:
 
 	- Inte VT-d:
 	 - IOMMU driver updated to the latest VT-d specification.
 	 - Don't enable PRS if PDS isn't supported.
 	 - Replace snprintf with scnprintf.
 	 - Fix legacy mode page table dump through debugfs.
 	 - Miscellaneous cleanups.
 
 	- AMD-Vi:
 	  - Support kdump boot when SNP is enabled.
 
 	- Apple-DART:
 	  - 4-level page-table support.
 
 	- RISC-V IOMMU:
 	  - ACPI support.
 
 	- Small number of miscellaneous cleanups and fixes.
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Merge tag 'iommu-updates-v6.18' of git://git.kernel.org/pub/scm/linux/kernel/git/iommu/linux

Pull iommu updates from Joerg Roedel:

 - Inte VT-d:
    - IOMMU driver updated to the latest VT-d specification
    - Don't enable PRS if PDS isn't supported
    - Replace snprintf with scnprintf
    - Fix legacy mode page table dump through debugfs
    - Miscellaneous cleanups

 - AMD-Vi:
     - Support kdump boot when SNP is enabled

 - Apple-DART:
     - 4-level page-table support

 - RISC-V IOMMU:
     - ACPI support

 - Small number of miscellaneous cleanups and fixes

* tag 'iommu-updates-v6.18' of git://git.kernel.org/pub/scm/linux/kernel/git/iommu/linux: (22 commits)
  iommu/vt-d: Disallow dirty tracking if incoherent page walk
  iommu/vt-d: debugfs: Avoid dumping context command register
  iommu/vt-d: Removal of Advanced Fault Logging
  iommu/vt-d: PRS isn't usable if PDS isn't supported
  iommu/vt-d: Remove LPIG from page group response descriptor
  iommu/vt-d: Drop unused cap_super_offset()
  iommu/vt-d: debugfs: Fix legacy mode page table dump logic
  iommu/vt-d: Replace snprintf with scnprintf in dmar_latency_snapshot()
  iommu/io-pgtable-dart: Fix off by one error in table index check
  iommu/riscv: Add ACPI support
  ACPI: scan: Add support for RISC-V in acpi_iommu_configure_id()
  ACPI: RISC-V: Add support for RIMT
  iommu/omap: Use int type to store negative error codes
  iommu/apple-dart: Clear stream error indicator bits for T8110 DARTs
  iommu/amd: Skip enabling command/event buffers for kdump
  crypto: ccp: Skip SEV and SNP INIT for kdump boot
  iommu/amd: Reuse device table for kdump
  iommu/amd: Add support to remap/unmap IOMMU buffers for kdump
  iommu/apple-dart: Add 4-level page table support
  iommu/io-pgtable-dart: Add 4-level page table support
  ...
2025-10-03 18:00:11 -07:00
Linus Torvalds
a498d59c46 dma-mapping updates for Linux 6.18:
- refactoring of DMA mapping API to physical addresses as the primary
 interface instead of page+offset parameters; this gets much closer to
 Matthew Wilcox's long term wish for struct-pageless IO to cacheable DRAM and is
 supporting memdesc project which seeks to substantially transform how
 struct page works; an advantage of this approach is the possibility of
 introducing DMA_ATTR_MMIO, which covers existing 'dma_map_resource' flow
 in the common paths, what in turn lets to use recently introduced
 dma_iova_link() API to map PCI P2P MMIO without creating struct page;
 developped by Leon Romanovsky and Jason Gunthorpe
 - minor clean-up by Petr Tesarik and Qianfeng Rong
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Merge tag 'dma-mapping-6.18-2025-09-30' of git://git.kernel.org/pub/scm/linux/kernel/git/mszyprowski/linux

Pull dma-mapping updates from Marek Szyprowski:

 - Refactoring of DMA mapping API to physical addresses as the primary
   interface instead of page+offset parameters

   This gets much closer to Matthew Wilcox's long term wish for
   struct-pageless IO to cacheable DRAM and is supporting memdesc
   project which seeks to substantially transform how struct page works.

   An advantage of this approach is the possibility of introducing
   DMA_ATTR_MMIO, which covers existing 'dma_map_resource' flow in the
   common paths, what in turn lets to use recently introduced
   dma_iova_link() API to map PCI P2P MMIO without creating struct page

   Developped by Leon Romanovsky and Jason Gunthorpe

 - Minor clean-up by Petr Tesarik and Qianfeng Rong

* tag 'dma-mapping-6.18-2025-09-30' of git://git.kernel.org/pub/scm/linux/kernel/git/mszyprowski/linux:
  kmsan: fix missed kmsan_handle_dma() signature conversion
  mm/hmm: properly take MMIO path
  mm/hmm: migrate to physical address-based DMA mapping API
  dma-mapping: export new dma_*map_phys() interface
  xen: swiotlb: Open code map_resource callback
  dma-mapping: implement DMA_ATTR_MMIO for dma_(un)map_page_attrs()
  kmsan: convert kmsan_handle_dma to use physical addresses
  dma-mapping: convert dma_direct_*map_page to be phys_addr_t based
  iommu/dma: implement DMA_ATTR_MMIO for iommu_dma_(un)map_phys()
  iommu/dma: rename iommu_dma_*map_page to iommu_dma_*map_phys
  dma-mapping: rename trace_dma_*map_page to trace_dma_*map_phys
  dma-debug: refactor to use physical addresses for page mapping
  iommu/dma: implement DMA_ATTR_MMIO for dma_iova_link().
  dma-mapping: introduce new DMA attribute to indicate MMIO memory
  swiotlb: Remove redundant __GFP_NOWARN
  dma-direct: clean up the logic in __dma_direct_alloc_pages()
2025-10-03 17:41:12 -07:00
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
Joerg Roedel
5f4b8c03f4 Merge branches 'apple/dart', 'ti/omap', 'riscv', 'intel/vt-d' and 'amd/amd-vi' into next 2025-09-26 10:03:33 +02:00
Lu Baolu
57f55048e5 iommu/vt-d: Disallow dirty tracking if incoherent page walk
Dirty page tracking relies on the IOMMU atomically updating the dirty bit
in the paging-structure entry. For this operation to succeed, the paging-
structure memory must be coherent between the IOMMU and the CPU. In
another word, if the iommu page walk is incoherent, dirty page tracking
doesn't work.

The Intel VT-d specification, Section 3.10 "Snoop Behavior" states:

"Remapping hardware encountering the need to atomically update A/EA/D bits
 in a paging-structure entry that is not snooped will result in a non-
 recoverable fault."

To prevent an IOMMU from being incorrectly configured for dirty page
tracking when it is operating in an incoherent mode, mark SSADS as
supported only when both ecap_slads and ecap_smpwc are supported.

Fixes: f35f22cc76 ("iommu/vt-d: Access/Dirty bit support for SS domains")
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20250924083447.123224-1-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2025-09-26 10:02:26 +02:00
Linus Torvalds
d4c7fccfa7 iommufd 6.17 second rc pull
Two user triggerable UAFs:
 
 - Possible race UAF setting up mmaps
 
 - Syzkaller found UAF when erroring an file descriptor creation ioctl due
   to the fput() work queue.
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Merge tag 'for-linus-iommufd' of git://git.kernel.org/pub/scm/linux/kernel/git/jgg/iommufd

Pull iommufd fixes from Jason Gunthorpe:
 "Fix two user triggerable use-after-free issues:

   - Possible race UAF setting up mmaps

   - Syzkaller found UAF when erroring an file descriptor creation ioctl
     due to the fput() work queue"

* tag 'for-linus-iommufd' of git://git.kernel.org/pub/scm/linux/kernel/git/jgg/iommufd:
  iommufd/selftest: Update the fail_nth limit
  iommufd: WARN if an object is aborted with an elevated refcount
  iommufd: Fix race during abort for file descriptors
  iommufd: Fix refcounting race during mmap
2025-09-22 11:16:14 -07:00
Jason Gunthorpe
53d0584eeb iommufd: WARN if an object is aborted with an elevated refcount
If something holds a refcount then it is at risk of UAFing. For abort
paths we expect the caller to never share the object with a parallel
thread and to clean up any refcounts it obtained on its own.

Add the missing dec inside iommufd_hwpt_paging_alloc() during error unwind
by making iommufd_hw_pagetable_attach/detach() proper pairs.

Link: https://patch.msgid.link/r/2-v1-02cd136829df+31-iommufd_syz_fput_jgg@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2025-09-19 10:34:49 -03:00
Jason Gunthorpe
4e034bf045 iommufd: Fix race during abort for file descriptors
fput() doesn't actually call file_operations release() synchronously, it
puts the file on a work queue and it will be released eventually.

This is normally fine, except for iommufd the file and the iommufd_object
are tied to gether. The file has the object as it's private_data and holds
a users refcount, while the object is expected to remain alive as long as
the file is.

When the allocation of a new object aborts before installing the file it
will fput() the file and then go on to immediately kfree() the obj. This
causes a UAF once the workqueue completes the fput() and tries to
decrement the users refcount.

Fix this by putting the core code in charge of the file lifetime, and call
__fput_sync() during abort to ensure that release() is called before
kfree. __fput_sync() is a bit too tricky to open code in all the object
implementations. Instead the objects tell the core code where the file
pointer is and the core will take care of the life cycle.

If the object is successfully allocated then the file will hold a users
refcount and the iommufd_object cannot be destroyed.

It is worth noting that close(); ioctl(IOMMU_DESTROY); doesn't have an
issue because close() is already using a synchronous version of fput().

The UAF looks like this:

    BUG: KASAN: slab-use-after-free in iommufd_eventq_fops_release+0x45/0xc0 drivers/iommu/iommufd/eventq.c:376
    Write of size 4 at addr ffff888059c97804 by task syz.0.46/6164

    CPU: 0 UID: 0 PID: 6164 Comm: syz.0.46 Not tainted syzkaller #0 PREEMPT(full)
    Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
    Call Trace:
     <TASK>
     __dump_stack lib/dump_stack.c:94 [inline]
     dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
     print_address_description mm/kasan/report.c:378 [inline]
     print_report+0xcd/0x630 mm/kasan/report.c:482
     kasan_report+0xe0/0x110 mm/kasan/report.c:595
     check_region_inline mm/kasan/generic.c:183 [inline]
     kasan_check_range+0x100/0x1b0 mm/kasan/generic.c:189
     instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
     atomic_fetch_sub_release include/linux/atomic/atomic-instrumented.h:400 [inline]
     __refcount_dec include/linux/refcount.h:455 [inline]
     refcount_dec include/linux/refcount.h:476 [inline]
     iommufd_eventq_fops_release+0x45/0xc0 drivers/iommu/iommufd/eventq.c:376
     __fput+0x402/0xb70 fs/file_table.c:468
     task_work_run+0x14d/0x240 kernel/task_work.c:227
     resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
     exit_to_user_mode_loop+0xeb/0x110 kernel/entry/common.c:43
     exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
     syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
     syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
     do_syscall_64+0x41c/0x4c0 arch/x86/entry/syscall_64.c:100
     entry_SYSCALL_64_after_hwframe+0x77/0x7f

Link: https://patch.msgid.link/r/1-v1-02cd136829df+31-iommufd_syz_fput_jgg@nvidia.com
Cc: stable@vger.kernel.org
Fixes: 07838f7fd5 ("iommufd: Add iommufd fault object")
Reviewed-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Nirmoy Das <nirmoyd@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Reported-by: syzbot+80620e2d0d0a33b09f93@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/r/68c8583d.050a0220.2ff435.03a2.GAE@google.com
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2025-09-19 10:34:49 -03:00
Jason Gunthorpe
7a425ec75d iommufd: Fix refcounting race during mmap
The owner object of the imap can be destroyed while the imap remains in
the mtree. So access to the imap pointer without holding locks is racy
with destruction.

The imap is safe to access outside the lock once a users refcount is
obtained, the owner object cannot start destruction until users is 0.

Thus the users refcount should not be obtained at the end of
iommufd_fops_mmap() but instead inside the mtree lock held around the
mtree_load(). Move the refcount there and use refcount_inc_not_zero() as
we can have a 0 refcount inside the mtree during destruction races.

Link: https://patch.msgid.link/r/0-v1-e6faace50971+3cc-iommufd_mmap_fix_jgg@nvidia.com
Cc: stable@vger.kernel.org
Fixes: 56e9a0d8e5 ("iommufd: Add mmap interface")
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2025-09-19 10:34:49 -03:00
Lu Baolu
5bd5ab53e7 iommu/vt-d: debugfs: Avoid dumping context command register
The register-based cache invalidation interface is in the process of being
replaced by the queued invalidation interface. The VT-d architecture
allows hardware implementations with a queued invalidation interface to
not implement the registers used for cache invalidation. Currently, the
debugfs interface dumps the Context Command Register unconditionally,
which is not reasonable.

Remove it to avoid potential access to non-present registers.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20250917025051.143853-1-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2025-09-19 09:43:21 +02:00
Lu Baolu
7d4e404102 iommu/vt-d: Removal of Advanced Fault Logging
The advanced fault logging has been removed from the specification since
v4.0. Linux doesn't implement advanced fault logging functionality, but
it currently dumps the advanced logging registers through debugfs. Remove
the dumping of these advanced fault logging registers through debugfs to
avoid potential access to non-present registers.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20250917024850.143801-1-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2025-09-19 09:43:21 +02:00
Lu Baolu
5ef7e24c74 iommu/vt-d: PRS isn't usable if PDS isn't supported
The specification, Section 7.10, "Software Steps to Drain Page Requests &
Responses," requires software to submit an Invalidation Wait Descriptor
(inv_wait_dsc) with the Page-request Drain (PD=1) flag set, along with
the Invalidation Wait Completion Status Write flag (SW=1). It then waits
for the Invalidation Wait Descriptor's completion.

However, the PD field in the Invalidation Wait Descriptor is optional, as
stated in Section 6.5.2.9, "Invalidation Wait Descriptor":

"Page-request Drain (PD): Remapping hardware implementations reporting
 Page-request draining as not supported (PDS = 0 in ECAP_REG) treat this
 field as reserved."

This implies that if the IOMMU doesn't support the PDS capability, software
can't drain page requests and group responses as expected.

Do not enable PCI/PRI if the IOMMU doesn't support PDS.

Reported-by: Joel Granados <joel.granados@kernel.org>
Closes: https://lore.kernel.org/r/20250909-jag-pds-v1-1-ad8cba0e494e@kernel.org
Fixes: 66ac4db36f ("iommu/vt-d: Add page request draining support")
Cc: stable@vger.kernel.org
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20250915062946.120196-1-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2025-09-19 09:43:21 +02:00
Lu Baolu
4402e8f39d iommu/vt-d: Remove LPIG from page group response descriptor
Bit 66 in the page group response descriptor used to be the LPIG (Last
Page in Group), but it was marked as Reserved since Specification 4.0.
Remove programming on this bit to make it consistent with the latest
specification.

Existing hardware all treats bit 66 of the page group response descriptor
as "ignored", therefore this change doesn't break any existing hardware.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20250901053943.1708490-1-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2025-09-19 09:43:20 +02:00
Yury Norov (NVIDIA)
4c48101364 iommu/vt-d: Drop unused cap_super_offset()
The macro is unused. Drop the dead code.

Signed-off-by: Yury Norov (NVIDIA) <yury.norov@gmail.com>
Link: https://lore.kernel.org/r/20250913015024.81186-1-yury.norov@gmail.com
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2025-09-19 09:43:20 +02:00
Vineeth Pillai (Google)
fbe6070c73 iommu/vt-d: debugfs: Fix legacy mode page table dump logic
In legacy mode, SSPTPTR is ignored if TT is not 00b or 01b. SSPTPTR
maybe uninitialized or zero in that case and may cause oops like:

 Oops: general protection fault, probably for non-canonical address
       0xf00087d3f000f000: 0000 [#1] SMP NOPTI
 CPU: 2 UID: 0 PID: 786 Comm: cat Not tainted 6.16.0 #191 PREEMPT(voluntary)
 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.17.0-5.fc42 04/01/2014
 RIP: 0010:pgtable_walk_level+0x98/0x150
 RSP: 0018:ffffc90000f279c0 EFLAGS: 00010206
 RAX: 0000000040000000 RBX: ffffc90000f27ab0 RCX: 000000000000001e
 RDX: 0000000000000003 RSI: f00087d3f000f000 RDI: f00087d3f0010000
 RBP: ffffc90000f27a00 R08: ffffc90000f27a98 R09: 0000000000000002
 R10: 0000000000000000 R11: 0000000000000000 R12: f00087d3f000f000
 R13: 0000000000000000 R14: 0000000040000000 R15: ffffc90000f27a98
 FS:  0000764566dcb740(0000) GS:ffff8881f812c000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000764566d44000 CR3: 0000000109d81003 CR4: 0000000000772ef0
 PKRU: 55555554
 Call Trace:
  <TASK>
  pgtable_walk_level+0x88/0x150
  domain_translation_struct_show.isra.0+0x2d9/0x300
  dev_domain_translation_struct_show+0x20/0x40
  seq_read_iter+0x12d/0x490
...

Avoid walking the page table if TT is not 00b or 01b.

Fixes: 2b437e8045 ("iommu/vt-d: debugfs: Support dumping a specified page table")
Signed-off-by: Vineeth Pillai (Google) <vineeth@bitbyteword.org>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Link: https://lore.kernel.org/r/20250814163153.634680-1-vineeth@bitbyteword.org
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2025-09-19 09:43:20 +02:00
Seyediman Seyedarab
75c02a0376 iommu/vt-d: Replace snprintf with scnprintf in dmar_latency_snapshot()
snprintf() returns the number of bytes that would have been written, not
the number actually written. Using this for offset tracking can cause
buffer overruns if truncation occurs.

Replace snprintf() with scnprintf() to ensure the offset stays within
bounds.

Since scnprintf() never returns a negative value, and zero is not possible
in this context because 'bytes' starts at 0 and 'size - bytes' is
DEBUG_BUFFER_SIZE in the first call, which is large enough to hold the
string literals used, the return value is always positive. An integer
overflow is also completely out of reach here due to the small and fixed
buffer size. The error check in latency_show_one() is therefore
unnecessary. Remove it and make dmar_latency_snapshot() return void.

Signed-off-by: Seyediman Seyedarab <ImanDevel@gmail.com>
Link: https://lore.kernel.org/r/20250731225048.131364-1-ImanDevel@gmail.com
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2025-09-19 09:43:19 +02:00
Vasant Hegde
1e56310b40 iommu/amd/pgtbl: Fix possible race while increase page table level
The AMD IOMMU host page table implementation supports dynamic page table levels
(up to 6 levels), starting with a 3-level configuration that expands based on
IOVA address. The kernel maintains a root pointer and current page table level
to enable proper page table walks in alloc_pte()/fetch_pte() operations.

The IOMMU IOVA allocator initially starts with 32-bit address and onces its
exhuasted it switches to 64-bit address (max address is determined based
on IOMMU and device DMA capability). To support larger IOVA, AMD IOMMU
driver increases page table level.

But in unmap path (iommu_v1_unmap_pages()), fetch_pte() reads
pgtable->[root/mode] without lock. So its possible that in exteme corner case,
when increase_address_space() is updating pgtable->[root/mode], fetch_pte()
reads wrong page table level (pgtable->mode). It does compare the value with
level encoded in page table and returns NULL. This will result is
iommu_unmap ops to fail and upper layer may retry/log WARN_ON.

CPU 0                                         CPU 1
------                                       ------
map pages                                    unmap pages
alloc_pte() -> increase_address_space()      iommu_v1_unmap_pages() -> fetch_pte()
  pgtable->root = pte (new root value)
                                             READ pgtable->[mode/root]
					       Reads new root, old mode
  Updates mode (pgtable->mode += 1)

Since Page table level updates are infrequent and already synchronized with a
spinlock, implement seqcount to enable lock-free read operations on the read path.

Fixes: 754265bcab ("iommu/amd: Fix race in increase_address_space()")
Reported-by: Alejandro Jimenez <alejandro.j.jimenez@oracle.com>
Cc: stable@vger.kernel.org
Cc: Joao Martins <joao.m.martins@oracle.com>
Cc: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Vasant Hegde <vasant.hegde@amd.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2025-09-19 09:39:40 +02:00
Vasant Hegde
a0c17ed907 iommu/amd: Fix alias device DTE setting
Commit 7bea695ada restructured DTE flag handling but inadvertently changed
the alias device configuration logic. This may cause incorrect DTE settings
for certain devices.

Add alias flag check before calling set_dev_entry_from_acpi(). Also move the
device iteration loop inside the alias check to restrict execution to cases
where alias devices are present.

Fixes: 7bea695ada ("iommu/amd: Introduce struct ivhd_dte_flags to store persistent DTE flags")
Cc: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Vasant Hegde <vasant.hegde@amd.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2025-09-13 08:11:30 +02:00
Janne Grunau
a2d2e6ea18 iommu/io-pgtable-dart: Fix off by one error in table index check
The check for the dart table index allowed values of
(1 << data->tbl_bits) while only as many entries are initialized in
apple_dart_alloc_pgtable. This results in an array out of bounds access
when data->tbl_bits is at its maximal value of 2. When data->tbl_bits is
0 or 1 an unset (initialized to zero) data->pgd[] entry is used. In both
cases the value is used as pointer to read page table entries and
results in dereferencing invalid pointers.
There is no prior check that the passed iova is inside the iommu's IAS
so invalid values can be passed from driver's calling iommu_map().

Fixes: 74a0e72f03 ("iommu/io-pgtable-dart: Add 4-level page table support")
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/asahi/aMACFlJjrZHs_Yf-@stanley.mountain/
Signed-off-by: Janne Grunau <j@jannau.net>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2025-09-13 08:07:25 +02:00
Leon Romanovsky
f7326196a7 dma-mapping: export new dma_*map_phys() interface
Introduce new DMA mapping functions dma_map_phys() and dma_unmap_phys()
that operate directly on physical addresses instead of page+offset
parameters. This provides a more efficient interface for drivers that
already have physical addresses available.

The new functions are implemented as the primary mapping layer, with
the existing dma_map_page_attrs()/dma_map_resource() and
dma_unmap_page_attrs()/dma_unmap_resource() functions converted to simple
wrappers around the phys-based implementations.

In case dma_map_page_attrs(), the struct page is converted to physical
address with help of page_to_phys() function and dma_map_resource()
provides physical address as is together with addition of DMA_ATTR_MMIO
attribute.

The old page-based API is preserved in mapping.c to ensure that existing
code won't be affected by changing EXPORT_SYMBOL to EXPORT_SYMBOL_GPL
variant for dma_*map_phys().

Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Link: https://lore.kernel.org/r/54cc52af91777906bbe4a386113437ba0bcfba9c.1757423202.git.leonro@nvidia.com
2025-09-12 00:18:21 +02:00
Leon Romanovsky
f9374de14c iommu/dma: implement DMA_ATTR_MMIO for iommu_dma_(un)map_phys()
Make iommu_dma_map_phys() and iommu_dma_unmap_phys() respect
DMA_ATTR_MMIO.

DMA_ATTR_MMIO makes the functions behave the same as
iommu_dma_(un)map_resource():
 - No swiotlb is possible
 - No cache flushing is done (ATTR_MMIO should not be cached memory)
 - prot for iommu_map() has IOMMU_MMIO not IOMMU_CACHE

This is preparation for replacing iommu_dma_map_resource() callers
with iommu_dma_map_phys(DMA_ATTR_MMIO) and removing
iommu_dma_(un)map_resource().

Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Link: https://lore.kernel.org/r/acc255bee358fec9c7da6b2a5904ee50abcd09f1.1757423202.git.leonro@nvidia.com
2025-09-12 00:18:20 +02:00
Leon Romanovsky
513559f737 iommu/dma: rename iommu_dma_*map_page to iommu_dma_*map_phys
Rename the IOMMU DMA mapping functions to better reflect their actual
calling convention. The functions iommu_dma_map_page() and
iommu_dma_unmap_page() are renamed to iommu_dma_map_phys() and
iommu_dma_unmap_phys() respectively, as they already operate on physical
addresses rather than page structures.

The calling convention changes from accepting (struct page *page,
unsigned long offset) to (phys_addr_t phys), which eliminates the need
for page-to-physical address conversion within the functions. This
renaming prepares for the broader DMA API conversion from page-based
to physical address-based mapping throughout the kernel.

All callers are updated to pass physical addresses directly, including
dma_map_page_attrs(), scatterlist mapping functions, and DMA page
allocation helpers. The change simplifies the code by removing the
page_to_phys() + offset calculation that was previously done inside
the IOMMU functions.

Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Link: https://lore.kernel.org/r/ed172f95f8f57782beae04f782813366894e98df.1757423202.git.leonro@nvidia.com
2025-09-12 00:18:20 +02:00
Leon Romanovsky
c288d657dd iommu/dma: implement DMA_ATTR_MMIO for dma_iova_link().
This will replace the hacky use of DMA_ATTR_SKIP_CPU_SYNC to avoid
touching the possibly non-KVA MMIO memory.

Also correct the incorrect caching attribute for the IOMMU, MMIO
memory should not be cachable inside the IOMMU mapping or it can
possibly create system problems. Set IOMMU_MMIO for DMA_ATTR_MMIO.

Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Link: https://lore.kernel.org/r/17ba63991aeaf8a80d5aca9ba5d028f1daa58f62.1757423202.git.leonro@nvidia.com
2025-09-12 00:08:07 +02:00
Niklas Schnelle
9ffaf52290 iommu/s390: Make attach succeed when the device was surprise removed
When a PCI device is removed with surprise hotplug, there may still be
attempts to attach the device to the default domain as part of tear down
via (__iommu_release_dma_ownership()), or because the removal happens
during probe (__iommu_probe_device()). In both cases zpci_register_ioat()
fails with a cc value indicating that the device handle is invalid. This
is because the device is no longer part of the instance as far as the
hypervisor is concerned.

Currently this leads to an error return and s390_iommu_attach_device()
fails. This triggers the WARN_ON() in __iommu_group_set_domain_nofail()
because attaching to the default domain must never fail.

With the device fenced by the hypervisor no DMAs to or from memory are
possible and the IOMMU translations have no effect. Proceed as if the
registration was successful and let the hotplug event handling clean up
the device.

This is similar to how devices in the error state are handled since
commit 59bbf59679 ("iommu/s390: Make attach succeed even if the device
is in error state") except that for removal the domain will not be
registered later. This approach was also previously discussed at the
link.

Handle both cases, error state and removal, in a helper which checks if
the error needs to be propagated or ignored. Avoid magic number
condition codes by using the pre-existing, but never used, defines for
PCI load/store condition codes and rename them to reflect that they
apply to all PCI instructions.

Cc: stable@vger.kernel.org # v6.2
Link: https://lore.kernel.org/linux-iommu/20240808194155.GD1985367@ziepe.ca/
Suggested-by: Jason Gunthorpe <jgg@ziepe.ca>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Link: https://lore.kernel.org/r/20250904-iommu_succeed_attach_removed-v1-1-e7f333d2f80f@linux.ibm.com
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2025-09-05 15:11:09 +02:00
Eugene Koira
dce043c07c iommu/vt-d: Fix __domain_mapping()'s usage of switch_to_super_page()
switch_to_super_page() assumes the memory range it's working on is aligned
to the target large page level. Unfortunately, __domain_mapping() doesn't
take this into account when using it, and will pass unaligned ranges
ultimately freeing a PTE range larger than expected.

Take for example a mapping with the following iov_pfn range [0x3fe400,
0x4c0600), which should be backed by the following mappings:

   iov_pfn [0x3fe400, 0x3fffff] covered by 2MiB pages
   iov_pfn [0x400000, 0x4bffff] covered by 1GiB pages
   iov_pfn [0x4c0000, 0x4c05ff] covered by 2MiB pages

Under this circumstance, __domain_mapping() will pass [0x400000, 0x4c05ff]
to switch_to_super_page() at a 1 GiB granularity, which will in turn
free PTEs all the way to iov_pfn 0x4fffff.

Mitigate this by rounding down the iov_pfn range passed to
switch_to_super_page() in __domain_mapping()
to the target large page level.

Additionally add range alignment checks to switch_to_super_page.

Fixes: 9906b9352a ("iommu/vt-d: Avoid duplicate removing in __domain_mapping()")
Signed-off-by: Eugene Koira <eugkoira@amazon.com>
Cc: stable@vger.kernel.org
Reviewed-by: Nicolas Saenz Julienne <nsaenz@amazon.com>
Reviewed-by: David Woodhouse <dwmw@amazon.co.uk>
Link: https://lore.kernel.org/r/20250826143816.38686-1-eugkoira@amazon.com
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2025-09-05 15:11:08 +02:00
Matthew Rosato
b3506e9bcc iommu/s390: Fix memory corruption when using identity domain
zpci_get_iommu_ctrs() returns counter information to be reported as part
of device statistics; these counters are stored as part of the s390_domain.
The problem, however, is that the identity domain is not backed by an
s390_domain and so the conversion via to_s390_domain() yields a bad address
that is zero'd initially and read on-demand later via a sysfs read.
These counters aren't necessary for the identity domain; just return NULL
in this case.

This issue was discovered via KASAN with reports that look like:
BUG: KASAN: global-out-of-bounds in zpci_fmb_enable_device
when using the identity domain for a device on s390.

Cc: stable@vger.kernel.org
Fixes: 64af12c6ec ("iommu/s390: implement iommu passthrough via identity domain")
Reported-by: Cam Miller <cam@linux.ibm.com>
Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
Tested-by: Cam Miller <cam@linux.ibm.com>
Reviewed-by: Farhan Ali <alifm@linux.ibm.com>
Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com>
Link: https://lore.kernel.org/r/20250827210828.274527-1-mjrosato@linux.ibm.com
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2025-09-05 15:11:07 +02:00
Zhen Ni
923b70581c iommu/amd: Fix ivrs_base memleak in early_amd_iommu_init()
Fix a permanent ACPI table memory leak in early_amd_iommu_init() when
CMPXCHG16B feature is not supported

Fixes: 82582f85ed ("iommu/amd: Disable AMD IOMMU if CMPXCHG16B feature is not supported")
Cc: stable@vger.kernel.org
Signed-off-by: Zhen Ni <zhen.ni@easystack.cn>
Reviewed-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Link: https://lore.kernel.org/r/20250822024915.673427-1-zhen.ni@easystack.cn
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2025-09-05 15:11:07 +02:00
Sunil V L
4f901b3dce iommu/riscv: Add ACPI support
RISC-V IO Mapping Table (RIMT) provides the information about the IOMMU
to the OS in ACPI. Add support for ACPI in RISC-V IOMMU drivers by using
RIMT data.

The changes at high level are,

a) Register the IOMMU with RIMT data structures.
b) Enable probing of platform IOMMU in ACPI way using the ACPIID defined
   for the RISC-V IOMMU in the BRS spec [1]. Configure the MSI domain if
   the platform IOMMU uses MSIs.

[1] - https://github.com/riscv-non-isa/riscv-brs/blob/main/acpi-id.adoc

Signed-off-by: Sunil V L <sunilvl@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20250818045807.763922-4-sunilvl@ventanamicro.com
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2025-09-05 15:06:06 +02:00
Qianfeng Rong
e520b2520c iommu/omap: Use int type to store negative error codes
Change the 'ret' variable from u32 to int to store negative error codes
or zero;

Storing the negative error codes in unsigned type, doesn't cause an issue
at runtime but it's ugly. Additionally, assigning negative error codes to
unsigned type may trigger a GCC warning when the -Wsign-conversion flag
is enabled.

No effect on runtime.

Signed-off-by: Qianfeng Rong <rongqianfeng@vivo.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20250829140219.121783-1-rongqianfeng@vivo.com
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2025-09-05 14:58:26 +02:00
Hector Martin
ecf6508923 iommu/apple-dart: Clear stream error indicator bits for T8110 DARTs
These registers exist and at least on the t602x variant the IRQ only
clears when theses are cleared.

Signed-off-by: Hector Martin <marcan@marcan.st>
Signed-off-by: Janne Grunau <j@jannau.net>
Reviewed-by: Sven Peter <sven@kernel.org>
Reviewed-by: Neal Gompa <neal@gompa.dev>
Link: https://lore.kernel.org/r/20250826-dart-t8110-stream-error-v1-1-e33395112014@jannau.net
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2025-09-05 14:47:16 +02:00
Ashish Kalra
9be15fbfc6 iommu/amd: Skip enabling command/event buffers for kdump
After a panic if SNP is enabled in the previous kernel then the kdump
kernel boots with IOMMU SNP enforcement still enabled.

IOMMU command buffers and event buffer registers remain locked and
exclusive to the previous kernel. Attempts to enable command and event
buffers in the kdump kernel will fail, as hardware ignores writes to
the locked MMIO registers as per AMD IOMMU spec Section 2.12.2.1.

Skip enabling command buffers and event buffers for kdump boot as they
are already enabled in the previous kernel.

Reviewed-by: Vasant Hegde <vasant.hegde@amd.com>
Tested-by: Sairaj Kodilkar <sarunkod@amd.com>
Signed-off-by: Ashish Kalra <ashish.kalra@amd.com>
Link: https://lore.kernel.org/r/576445eb4f168b467b0fc789079b650ca7c5b037.1756157913.git.ashish.kalra@amd.com
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2025-09-05 14:45:17 +02:00
Ashish Kalra
38e5f33ee3 iommu/amd: Reuse device table for kdump
After a panic if SNP is enabled in the previous kernel then the kdump
kernel boots with IOMMU SNP enforcement still enabled.

IOMMU device table register is locked and exclusive to the previous
kernel. Attempts to copy old device table from the previous kernel
fails in kdump kernel as hardware ignores writes to the locked device
table base address register as per AMD IOMMU spec Section 2.12.2.1.

This causes the IOMMU driver (OS) and the hardware to reference
different memory locations. As a result, the IOMMU hardware cannot
process the command which results in repeated "Completion-Wait loop
timed out" errors and a second kernel panic: "Kernel panic - not
syncing: timer doesn't work through Interrupt-remapped IO-APIC".

Reuse device table instead of copying device table in case of kdump
boot and remove all copying device table code.

Reviewed-by: Vasant Hegde <vasant.hegde@amd.com>
Tested-by: Sairaj Kodilkar <sarunkod@amd.com>
Signed-off-by: Ashish Kalra <ashish.kalra@amd.com>
Link: https://lore.kernel.org/r/3a31036fb2f7323e6b1a1a1921ac777e9f7bdddc.1756157913.git.ashish.kalra@amd.com
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2025-09-05 14:44:32 +02:00
Ashish Kalra
f32fe7cb01 iommu/amd: Add support to remap/unmap IOMMU buffers for kdump
After a panic if SNP is enabled in the previous kernel then the kdump
kernel boots with IOMMU SNP enforcement still enabled.

IOMMU completion wait buffers (CWBs), command buffers and event buffer
registers remain locked and exclusive to the previous kernel. Attempts
to allocate and use new buffers in the kdump kernel fail, as hardware
ignores writes to the locked MMIO registers as per AMD IOMMU spec
Section 2.12.2.1.

This results in repeated "Completion-Wait loop timed out" errors and a
second kernel panic: "Kernel panic - not syncing: timer doesn't work
through Interrupt-remapped IO-APIC"

The list of MMIO registers locked and which ignore writes after failed
SNP shutdown are mentioned in the AMD IOMMU specifications below:

Section 2.12.2.1.
https://docs.amd.com/v/u/en-US/48882_3.10_PUB

Reuse the pages of the previous kernel for completion wait buffers,
command buffers, event buffers and memremap them during kdump boot
and essentially work with an already enabled IOMMU configuration and
re-using the previous kernel’s data structures.

Reusing of command buffers and event buffers is now done for kdump boot
irrespective of SNP being enabled during kdump.

Re-use of completion wait buffers is only done when SNP is enabled as
the exclusion base register is used for the completion wait buffer
(CWB) address only when SNP is enabled.

Reviewed-by: Vasant Hegde <vasant.hegde@amd.com>
Tested-by: Sairaj Kodilkar <sarunkod@amd.com>
Signed-off-by: Ashish Kalra <ashish.kalra@amd.com>
Link: https://lore.kernel.org/r/ff04b381a8fe774b175c23c1a336b28bc1396511.1756157913.git.ashish.kalra@amd.com
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2025-09-05 14:44:30 +02:00
Hector Martin
5229bd5f9e iommu/apple-dart: Add 4-level page table support
The T8110 variant DART implementation on T602x SoCs indicates an IAS of
42, which requires an extra page table level. The extra level is
optional, but let's implement it.

Later it might be useful to restrict this based on the actual attached
devices, since most won't need that much address space anyway.

Signed-off-by: Hector Martin <marcan@marcan.st>
Signed-off-by: Janne Grunau <j@jannau.net>
Reviewed-by: Sven Peter <sven@kernel.org>
Reviewed-by: Neal Gompa <neal@gompa.dev>
Link: https://lore.kernel.org/r/20250821-apple-dart-4levels-v2-3-e39af79daa37@jannau.net
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2025-09-05 14:27:32 +02:00
Hector Martin
74a0e72f03 iommu/io-pgtable-dart: Add 4-level page table support
DARTs on t602x SoCs are of the t8110 variant but have an IAS of 42,
which means optional support for an extra page table level.

Refactor the PTE management to support an arbitrary level count, and
then calculate how many levels we need for any given configuration.

Signed-off-by: Hector Martin <marcan@marcan.st>
Signed-off-by: Janne Grunau <j@jannau.net>
Reviewed-by: Sven Peter <sven@kernel.org>
Reviewed-by: Neal Gompa <neal@gompa.dev>
Link: https://lore.kernel.org/r/20250821-apple-dart-4levels-v2-2-e39af79daa37@jannau.net
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2025-09-05 14:27:31 +02:00
Hector Martin
1268890086 iommu/apple-dart: Make the hw register fields u32s
The registers are 32-bit and the offsets definitely don't need 64 bits
either, these should've been u32s.

Signed-off-by: Hector Martin <marcan@marcan.st>
Signed-off-by: Janne Grunau <j@jannau.net>
Reviewed-by: Sven Peter <sven@kernel.org>
Reviewed-by: Neal Gompa <neal@gompa.dev>
Link: https://lore.kernel.org/r/20250821-apple-dart-4levels-v2-1-e39af79daa37@jannau.net
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2025-09-05 14:27:31 +02:00
Xichao Zhao
d3d3b60427 iommu/amd: use str_plural() to simplify the code
Use the string choice helper function str_plural() to simplify the code.

Signed-off-by: Xichao Zhao <zhao.xichao@vivo.com>
Reviewed-by: Ankit Soni <Ankit.Soni@amd.com>
Link: https://lore.kernel.org/r/20250818070556.458271-1-zhao.xichao@vivo.com
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2025-09-05 14:25:32 +02:00
Linus Torvalds
471b25a2fc iommufd 6.17 first rc pull
- Fix mismatched kvalloc()/kfree()
 
 - Spelling fixes in documentation
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Merge tag 'for-linus-iommufd' of git://git.kernel.org/pub/scm/linux/kernel/git/jgg/iommufd

Pull iommufd fixes from Jason Gunthorpe:
 "Two very minor fixes:

   - Fix mismatched kvalloc()/kfree()

   - Spelling fixes in documentation"

* tag 'for-linus-iommufd' of git://git.kernel.org/pub/scm/linux/kernel/git/jgg/iommufd:
  iommufd: Fix spelling errors in iommufd.rst
  iommufd: viommu: free memory allocated by kvcalloc() using kvfree()
2025-08-22 17:24:48 -04:00
XianLiang Huang
99d4d1a070 iommu/riscv: prevent NULL deref in iova_to_phys
The riscv_iommu_pte_fetch() function returns either NULL for
unmapped/never-mapped iova, or a valid leaf pte pointer that
requires no further validation.

riscv_iommu_iova_to_phys() failed to handle NULL returns.
Prevent null pointer dereference in
riscv_iommu_iova_to_phys(), and remove the pte validation.

Fixes: 488ffbf181 ("iommu/riscv: Paging domain support")
Cc: Tomasz Jeznach <tjeznach@rivosinc.com>
Signed-off-by: XianLiang Huang <huangxianliang@lanxincomputing.com>
Link: https://lore.kernel.org/r/20250820072248.312-1-huangxianliang@lanxincomputing.com
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2025-08-22 08:51:49 +02:00
Robin Murphy
72b6f7cd89 iommu/virtio: Make instance lookup robust
Much like arm-smmu in commit 7d835134d4 ("iommu/arm-smmu: Make
instance lookup robust"), virtio-iommu appears to have the same issue
where iommu_device_register() makes the IOMMU instance visible to other
API callers (including itself) straight away, but internally the
instance isn't ready to recognise itself for viommu_probe_device() to
work correctly until after viommu_probe() has returned. This matters a
lot more now that bus_iommu_probe() has the DT/VIOT knowledge to probe
client devices the way that was always intended. Tweak the lookup and
initialisation in much the same way as for arm-smmu, to ensure that what
we register is functional and ready to go.

Cc: stable@vger.kernel.org
Fixes: bcb81ac6ae ("iommu: Get DT/ACPI parsing into the proper probe path")
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Tested-by: Eric Auger <eric.auger@redhat.com>
Link: https://lore.kernel.org/r/308911aaa1f5be32a3a709996c7bd6cf71d30f33.1755190036.git.robin.murphy@arm.com
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2025-08-22 08:43:23 +02:00
Nicolin Chen
685ca577b4 iommu/arm-smmu-v3: Fix smmu_domain->nr_ats_masters decrement
The arm_smmu_attach_commit() updates master->ats_enabled before calling
arm_smmu_remove_master_domain() that is supposed to clean up everything
in the old domain, including the old domain's nr_ats_masters. So, it is
supposed to use the old ats_enabled state of the device, not an updated
state.

This isn't a problem if switching between two domains where:
 - old ats_enabled = false; new ats_enabled = false
 - old ats_enabled = true;  new ats_enabled = true
but can fail cases where:
 - old ats_enabled = false; new ats_enabled = true
   (old domain should keep the counter but incorrectly decreased it)
 - old ats_enabled = true;  new ats_enabled = false
   (old domain needed to decrease the counter but incorrectly missed it)

Update master->ats_enabled after arm_smmu_remove_master_domain() to fix
this.

Fixes: 7497f4211f ("iommu/arm-smmu-v3: Make changing domains be hitless for ATS")
Cc: stable@vger.kernel.org
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Acked-by: Will Deacon <will@kernel.org>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Pranjal Shrivastava <praan@google.com>
Link: https://lore.kernel.org/r/20250801030127.2006979-1-nicolinc@nvidia.com
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2025-08-22 08:41:20 +02:00
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
Nicolin Chen
41f0200c71 iommu/tegra241-cmdqv: Fix missing cpu_to_le64 at lvcmdq_err_map
Sparse reported a warning:
drivers/iommu/arm/arm-smmu-v3/tegra241-cmdqv.c:305:47:
	sparse:     expected restricted __le64
	sparse:     got unsigned long long

Add cpu_to_le64() to fix that.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202508142105.Jb5Smjsg-lkp@intel.com/
Suggested-by: Pranjal Shrivastava <praan@google.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Link: https://lore.kernel.org/r/20250814193039.2265813-1-nicolinc@nvidia.com
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2025-08-15 12:02:24 +02:00