kernel/drivers/iommu/intel/dmar.c, branch master

iommu/vt-d: Fix intel iommu iotlb sync hardlockup and retry

2026-03-17T12:20:06Z

During the qi_check_fault process after an IOMMU ITE event, requests at odd-numbered positions in the queue are set to QI_ABORT, only satisfying single-request submissions. However, qi_submit_sync now supports multiple simultaneous submissions, and can't guarantee that the wait_desc will be at an odd-numbered position. Therefore, if an item times out, IOMMU can't re-initiate the request, resulting in an infinite polling wait. This modifies the process by setting the status of all requests already fetched by IOMMU and recorded as QI_IN_USE status (including wait_desc requests) to QI_ABORT, thus enabling multiple requests to be resubmitted. Fixes: 8a1d82462540 ("iommu/vt-d: Multiple descriptors per qi_submit_sync()") Cc: stable@vger.kernel.org Signed-off-by: Guanghui Feng Tested-by: Shuai Xue Reviewed-by: Shuai Xue Reviewed-by: Samiullah Khawaja Link: https://lore.kernel.org/r/20260306101516.3885775-1-guanghuifeng@linux.alibaba.com Signed-off-by: Lu Baolu Fixes: 8a1d82462540 ("iommu/vt-d: Multiple descriptors per qi_submit_sync()") Signed-off-by: Joerg Roedel

Convert 'alloc_obj' family to use the new default GFP_KERNEL argument

2026-02-22T01:09:51Z

This was done entirely with mindless brute force, using git grep -l '\

treewide: Replace kmalloc with kmalloc_obj for non-scalar types

2026-02-21T09:02:28Z

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

iommu/vt-d: Remove the CONFIG_X86 wrapping from iommu init hook

2025-07-14T10:18:03Z

iommu init hook is wrapped in CONFI_X86 and is a remnant of dmar.c when it was a common code in "drivers/pci/dmar.c". This was added in commit (9d5ce73a64be2 x86: intel-iommu: Convert detect_intel_iommu to use iommu_init hook) Now this is built only for x86. This config wrap could be removed. Signed-off-by: Vineeth Pillai (Google) Reviewed-by: Jason Gunthorpe Link: https://lore.kernel.org/r/20250616131740.3499289-1-vineeth@bitbyteword.org Signed-off-by: Lu Baolu Link: https://lore.kernel.org/r/20250714045028.958850-2-baolu.lu@linux.intel.com Signed-off-by: Will Deacon

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

2025-05-23T15:14:32Z

iommu/vt-d: Replace spin_lock with mutex to protect domain ida

2025-05-16T06:49:28Z

The domain ID allocator is currently protected by a spin_lock. However, ida_alloc_range can potentially block if it needs to allocate memory to grow its internal structures. Replace the spin_lock with a mutex which allows sleep on block. Thus, the memory allocation flags can be updated from GFP_ATOMIC to GFP_KERNEL to allow blocking memory allocations if necessary. Introduce a new mutex, did_lock, specifically for protecting the domain ida. The existing spinlock will remain for protecting other intel_iommu fields. Signed-off-by: Lu Baolu Reviewed-by: Kevin Tian Reviewed-by: Jason Gunthorpe Link: https://lore.kernel.org/r/20250430021135.2370244-3-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel

iommu/vt-d: Use ida to manage domain id

2025-05-16T06:49:27Z

Switch the intel iommu driver to use the ida mechanism for managing domain IDs, replacing the previous fixed-size bitmap. The previous approach allocated a bitmap large enough to cover the maximum number of domain IDs supported by the hardware, regardless of the actual number of domains in use. This led to unnecessary memory consumption, especially on systems supporting a large number of iommu units but only utilizing a small number of domain IDs. The ida allocator dynamically manages the allocation and freeing of integer IDs, only consuming memory for the IDs that are currently in use. This significantly optimizes memory usage compared to the fixed-size bitmap. Signed-off-by: Lu Baolu Reviewed-by: Kevin Tian Reviewed-by: Jason Gunthorpe Link: https://lore.kernel.org/r/20250430021135.2370244-2-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel

iommu: Update various drivers to pass in lg2sz instead of order to iommu pages

2025-04-17T14:22:48Z

Convert most of the places calling get_order() as an argument to the iommu-pages allocator into order_base_2() or the _sz flavour instead. These places already have an exact size, there is no particular reason to use order here. Reviewed-by: Lu Baolu Tested-by: Nicolin Chen Tested-by: Alejandro Jimenez Signed-off-by: Jason Gunthorpe Link: https://lore.kernel.org/r/19-v4-c8663abbb606+3f7-iommu_pages_jgg@nvidia.com Signed-off-by: Joerg Roedel

iommu/pages: Remove iommu_free_page()

2025-04-17T14:22:36Z

Use iommu_free_pages() instead. Reviewed-by: Lu Baolu Reviewed-by: Mostafa Saleh Tested-by: Alejandro Jimenez Signed-off-by: Jason Gunthorpe Link: https://lore.kernel.org/r/6-v4-c8663abbb606+3f7-iommu_pages_jgg@nvidia.com Signed-off-by: Joerg Roedel

iommu/vt-d: Fix suspicious RCU usage

2025-02-28T11:19:01Z

Commit ("iommu/vt-d: Allocate DMAR fault interrupts locally") moved the call to enable_drhd_fault_handling() to a code path that does not hold any lock while traversing the drhd list. Fix it by ensuring the dmar_global_lock lock is held when traversing the drhd list. Without this fix, the following warning is triggered: ============================= WARNING: suspicious RCU usage 6.14.0-rc3 #55 Not tainted ----------------------------- drivers/iommu/intel/dmar.c:2046 RCU-list traversed in non-reader section!! other info that might help us debug this: rcu_scheduler_active = 1, debug_locks = 1 2 locks held by cpuhp/1/23: #0: ffffffff84a67c50 (cpu_hotplug_lock){++++}-{0:0}, at: cpuhp_thread_fun+0x87/0x2c0 #1: ffffffff84a6a380 (cpuhp_state-up){+.+.}-{0:0}, at: cpuhp_thread_fun+0x87/0x2c0 stack backtrace: CPU: 1 UID: 0 PID: 23 Comm: cpuhp/1 Not tainted 6.14.0-rc3 #55 Call Trace: dump_stack_lvl+0xb7/0xd0 lockdep_rcu_suspicious+0x159/0x1f0 ? __pfx_enable_drhd_fault_handling+0x10/0x10 enable_drhd_fault_handling+0x151/0x180 cpuhp_invoke_callback+0x1df/0x990 cpuhp_thread_fun+0x1ea/0x2c0 smpboot_thread_fn+0x1f5/0x2e0 ? __pfx_smpboot_thread_fn+0x10/0x10 kthread+0x12a/0x2d0 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x4a/0x60 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1a/0x30 Holding the lock in enable_drhd_fault_handling() triggers a lockdep splat about a possible deadlock between dmar_global_lock and cpu_hotplug_lock. This is avoided by not holding dmar_global_lock when calling iommu_device_register(), which initiates the device probe process. Fixes: d74169ceb0d2 ("iommu/vt-d: Allocate DMAR fault interrupts locally") Reported-and-tested-by: Ido Schimmel Closes: https://lore.kernel.org/linux-iommu/Zx9OwdLIc_VoQ0-a@shredder.mtl.com/ Tested-by: Breno Leitao Cc: stable@vger.kernel.org Signed-off-by: Lu Baolu Reviewed-by: Kevin Tian Link: https://lore.kernel.org/r/20250218022422.2315082-1-baolu.lu@linux.intel.com Tested-by: Ido Schimmel Signed-off-by: Joerg Roedel