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path: root/drivers/iommu/amd/nested.c
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6 daysiommu/amd: Fix ineffective error check in nested domain allocationHemanth Selam
amd_iommu_pdom_id_alloc() returns an int: a domain ID on success, or the negative errno from ida_alloc_range() when the ID space is exhausted or memory is short. amd_iommu_alloc_domain_nested() stores that return value in gdom_info->hdom_id, which is a u32, and only then tests it: gdom_info->hdom_id = amd_iommu_pdom_id_alloc(); if (gdom_info->hdom_id <= 0) { The assignment discards the sign, so -ENOSPC becomes 0xffffffe4 and the test never fires. The nested domain is then set up with a host domain ID that was never allocated, instead of the allocation failing with -ENOSPC. Keep the value in an int, test it there, and store it only once it is known to be valid, which is what the other amd_iommu_pdom_id_alloc() callers already do. Fixes: 757d2b1fdf5b ("iommu/amd: Introduce gDomID-to-hDomID Mapping and handle parent domain invalidation") Signed-off-by: Hemanth Selam <hemanth.selam@gmail.com> Reviewed-by: Vasant Hegde <vasant.hegde@amd.com> Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2026-07-15iommu/amd: Fix nested domain leakTycho Andersen (AMD)
A couple of runs of different AI tools have generated something like the following bug report: In nested_domain_free(), when refcount_dec_and_test() returns false (other nested domains still reference the same gdom_info), the function returns without calling kfree(ndom), leaking the nested_domain structure. This problem wasn't introduced by this patch, but exists in the code from commit 757d2b1fdf5b that the patch modifies. Each nested_domain (ndom) is allocated individually in amd_iommu_alloc_domain_nested() via kzalloc_obj(*ndom). The .free callback is the sole point responsible for freeing this domain. When the refcount is > 0, only the xa_unlock_irqrestore is performed and the function returns, leaving ndom permanently allocated. This leak occurs every time a nested domain sharing a gDomID is destroyed while other domains still use that gDomID. There is a similar leak later in this function in the WARN_ON() test when the mapping is already NULL. Switch to a RAII-based cleanup for ndom, since it should always be freed in this function. Fixes: 757d2b1fdf5b ("iommu/amd: Introduce gDomID-to-hDomID Mapping and handle parent domain invalidation") Signed-off-by: Tycho Andersen (AMD) <tycho@kernel.org> Reviewed-by: Ankit Soni <Ankit.Soni@amd.com> Signed-off-by: Will Deacon <will@kernel.org>
2026-07-15iommu/amd: Fix IRQ unsafe locking in gdom allocationTycho Andersen (AMD)
Lockdep complains: [ 259.410489] ===================================================== [ 259.417287] WARNING: HARDIRQ-safe -> HARDIRQ-unsafe lock order detected [ 259.424667] 7.0.0-g51db1d8d2113 #54 Not tainted [ 259.429718] ----------------------------------------------------- [ 259.436516] qemu-system-x86/10143 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire: [ 259.444670] ff3b2b1c60305170 (&xa->xa_lock#25){+.+.}-{3:3}, at: __domain_flush_pages+0x17c/0x4b0 [ 259.454485] and this task is already holding: [ 259.460991] ff3b2b1c98504cc0 (&domain->lock){-.-.}-{3:3}, at: amd_iommu_iotlb_sync+0x25/0x60 [ 259.470408] which would create a new lock dependency: [ 259.476041] (&domain->lock){-.-.}-{3:3} -> (&xa->xa_lock#25){+.+.}-{3:3} [ 259.483615] but this new dependency connects a HARDIRQ-irq-safe lock: [ 259.492447] (&domain->lock){-.-.}-{3:3} [ 259.492449] ... which became HARDIRQ-irq-safe at: [ 259.503705] lock_acquire+0xb6/0x2e0 [ 259.507790] _raw_spin_lock_irqsave+0x3e/0x60 [ 259.512748] amd_iommu_flush_iotlb_all+0x20/0x50 [ 259.517996] iommu_dma_free_iova.isra.0+0x1b8/0x1e0 [ 259.523534] __iommu_dma_unmap+0xc2/0x140 [ 259.528100] iommu_dma_unmap_phys+0x55/0xc0 [ 259.532863] dma_unmap_phys+0x274/0x2e0 [ 259.537238] dma_unmap_page_attrs+0x17/0x30 [ 259.542000] nvme_unmap_data+0x13e/0x280 [ 259.546473] nvme_pci_complete_batch+0x45/0x70 [ 259.551524] nvme_irq+0x83/0x90 [ 259.555123] __handle_irq_event_percpu+0x92/0x360 [ 259.560466] handle_irq_event+0x39/0x80 [ 259.564841] handle_edge_irq+0xb2/0x1a0 [ 259.569214] __common_interrupt+0x4e/0x130 [ 259.573882] common_interrupt+0x88/0xa0 [ 259.578256] asm_common_interrupt+0x27/0x40 [ 259.583019] cpuidle_enter_state+0x119/0x5d0 [ 259.587877] cpuidle_enter+0x2e/0x50 [ 259.591962] do_idle+0x153/0x2c0 [ 259.595657] cpu_startup_entry+0x29/0x30 [ 259.600128] start_secondary+0x118/0x150 [ 259.604601] common_startup_64+0x13e/0x141 [ 259.609266] to a HARDIRQ-irq-unsafe lock: [ 259.615384] (&xa->xa_lock#25){+.+.}-{3:3} [ 259.615386] ... which became HARDIRQ-irq-unsafe at: [ 259.627039] ... [ 259.627039] lock_acquire+0xb6/0x2e0 [ 259.633071] _raw_spin_lock+0x2f/0x50 [ 259.637250] amd_iommu_alloc_domain_nested+0x140/0x3c0 [ 259.643078] iommufd_hwpt_alloc+0x272/0x800 [iommufd] [ 259.648813] iommufd_fops_ioctl+0x14e/0x200 [iommufd] [ 259.654547] __x64_sys_ioctl+0x9d/0xf0 ... Since amd_iommu_domain_flush_pages() necessarily holds domain->lock to do the flush, switch the allocation side in gdom_info_load_or_alloc_locked() to HARDIRQ-safe allocation. The IOMMU_DESTROY->free path has the same issue, so switch that path to HARDIRQ-safe locking as well. Fixes: 757d2b1fdf5b ("iommu/amd: Introduce gDomID-to-hDomID Mapping and handle parent domain invalidation") Signed-off-by: Tycho Andersen (AMD) <tycho@kernel.org> Reviewed-by: Ankit Soni <Ankit.Soni@amd.com> Signed-off-by: Will Deacon <will@kernel.org>
2026-02-21Convert 'alloc_obj' family to use the new default GFP_KERNEL argumentLinus Torvalds
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>
2026-02-21treewide: Replace kmalloc with kmalloc_obj for non-scalar typesKees Cook
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>
2026-01-18iommu/amd: Add support for nested domain attach/detachSuravee Suthikulpanit
Introduce set_dte_nested() to program guest translation settings in the host DTE when attaches the nested domain to a device. Reviewed-by: Nicolin Chen <nicolinc@nvidia.com> Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com> Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2026-01-18iommu/amd: Introduce gDomID-to-hDomID Mapping and handle parent domain ↵Suravee Suthikulpanit
invalidation Each nested domain is assigned guest domain ID (gDomID), which guest OS programs into guest Device Table Entry (gDTE). For each gDomID, the driver assigns a corresponding host domain ID (hDomID), which will be programmed into the host Device Table Entry (hDTE). The hDomID is allocated during amd_iommu_alloc_domain_nested(), and free during nested_domain_free(). The gDomID-to-hDomID mapping info (struct guest_domain_mapping_info) is stored in a per-viommu xarray (struct amd_iommu_viommu.gdomid_array), which is indexed by gDomID. Note also that parent domain can be shared among struct iommufd_viommu. Therefore, when hypervisor invalidates the nest parent domain, the AMD IOMMU command INVALIDATE_IOMMU_PAGES must be issued for each hDomID in the gdomid_array. This is handled by the iommu_flush_pages_v1_hdom_ids(), where it iterates through struct protection_domain.viommu_list. Suggested-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com> Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2026-01-18iommu/amd: Add support for nested domain allocationSuravee Suthikulpanit
The nested domain is allocated with IOMMU_DOMAIN_NESTED type to store stage-1 translation (i.e. GVA->GPA). This includes the GCR3 root pointer table along with guest page tables. The struct iommu_hwpt_amd_guest contains this information, and is passed from user-space as a parameter of the struct iommu_ops.domain_alloc_nested(). Reviewed-by: Nicolin Chen <nicolinc@nvidia.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com> Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>