kernel/linux.git/drivers/iommu, branch v6.6.155

iommu/sva: move x86 disable check before allocation

2026-08-09T18:22:00+00:00

Backport of commit 72f98ef9a4be ("iommu: disable SVA when CONFIG_X86 is set") placed the IS_ENABLED(CONFIG_X86) early-return in iommu_sva_bind_device() after iommu_sva_alloc_pasid() and kzalloc(handle), while upstream puts it at the function start. On x86 this leaks the kzalloc'd struct iommu_sva (early return skips kfree) and a globally allocated PASID (mm->pasid wrongly set, never unbound). Move the check before any allocation/side effect. Fixes: 240cd7f2812c ("iommu: disable SVA when CONFIG_X86 is set") Signed-off-by: Wei Yang Acked-by: Lu Baolu Signed-off-by: Sasha Levin

iommu/amd: Don't split flush for amd_iommu_domain_flush_all()

2026-08-03T09:15:33+00:00

[ Upstream commit 69fe699afe1afcb730164b86c228483c2da05f94 ] We have observed multiple full invalidations occurring during device detach when we are done using the vfio-device. blocked_domain_attach_device() -> detach_device() -> amd_iommu_domain_flush_all() -> amd_iommu_domain_flush_pages(..., CMD_INV_IOMMU_ALL_PAGES_ADDRESS) while (size != 0) { -> __domain_flush_pages( flush_size /* power of 2 flush_size */) -> domain_flush_pages_v1() -> build_inv_iommu_pages() -> build_inv_address() } build_inv_address() will trigger a full invalidation if the chunk size > (1 << 51). Consequently, the guest will issue multiple full invalidations for a single call to amd_iommu_domain_flush_all() Without this patch, we will see 10 time instead of 1 time full invalidations for every amd_iommu_domain_flush_all(). Cc: stable@vger.kernel.org Fixes: a270be1b3fdf ("iommu/amd: Use only natural aligned flushes in a VM") Suggested-by: Josef Bacik Suggested-by: Jason Gunthorpe Signed-off-by: Weinan Liu Reviewed-by: Wei Wang Reviewed-by: Jason Gunthorpe Reviewed-by: Samiullah Khawaja Reviewed-by: Suravee Suthikulpanit Reviewed-by: Vasant Hegde Signed-off-by: Joerg Roedel Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

iommu/vt-d: Disallow SVA if page walk is not coherent

2026-08-03T09:15:30+00:00

commit 780dfed688622ea01be3c9c2c55eec2207f05e04 upstream. Hardware implementations report Scalable-Mode Page-walk Coherency Support via the SMPWCS field in the extended capability register. If the hardware does not support page-walk coherency, a clflush is required every time the page table entries (which are walked by the IOMMU hardware) are updated. In the SVA case, page tables are managed by the CPU mm core, not by the IOMMU driver. Because the IOMMU driver has no way of knowing whether the CPU page table management code has ensured coherency via clflush, the driver must deny SVA if the hardware does not support coherent paging. Fixes: ff3dc6521f78 ("iommu/vt-d: Fix CPU and IOMMU SVM feature matching checks") Cc: stable@vger.kernel.org Signed-off-by: Lu Baolu Reviewed-by: Kevin Tian Reviewed-by: Samiullah Khawaja Reviewed-by: Jason Gunthorpe Signed-off-by: Will Deacon Signed-off-by: Greg Kroah-Hartman

iommu/intel: Fix out-of-bounds memset in dmar_latency_disable()

2026-08-03T09:15:20+00:00

[ Upstream commit 754f8efe45f87e3a9c6871b645b2f9d46d1b407b ] dmar_latency_disable() intends to zero out only the single latency_statistic entry for the given type, but the memset size was computed as sizeof(*lstat) * DMAR_LATENCY_NUM, which clears the entire array starting from &lstat[type]. When type > 0, this writes beyond the end of the allocated array, corrupting adjacent memory. Fix by using sizeof(*lstat) to clear only the target entry. Fixes: 55ee5e67a59a ("iommu/vt-d: Add common code for dmar latency performance monitors") Signed-off-by: Li RongQing Signed-off-by: Will Deacon Signed-off-by: Sasha Levin

iommu/amd: Bound the early ACPI HID map

2026-08-03T09:15:20+00:00

[ Upstream commit fb80117fddb5b477218dc99bb53911b72c3847f8 ] The ivrs_acpihid command-line parser appends entries to a fixed four-element early_acpihid_map array. Unlike the sibling IOAPIC and HPET parsers, it does not reject a fifth entry before incrementing the map size. Check the capacity at the common found label before parsing the HID and UID or writing the entry. Fixes: ca3bf5d47cec ("iommu/amd: Introduces ivrs_acpihid kernel parameter") Signed-off-by: Pengpeng Hou Reviewed-by: Ankit Soni Signed-off-by: Will Deacon Signed-off-by: Sasha Levin

iommu/amd: Wait for completion instead of returning early in iommu_completion_wait()

2026-08-03T09:15:19+00:00

[ Upstream commit 1e75a8255f11c81fb07e81e5029cfd75804350a0 ] need_sync is a per-IOMMU flag shared by all domains and devices behind that IOMMU. It is set whenever a command is queued with sync == true and cleared when a completion-wait (CWAIT) command is queued. However, a cleared need_sync only means that a covering CWAIT has been queued, not that all previously queued commands have actually completed in hardware. iommu_completion_wait() read need_sync locklessly and returned early when it was false. This breaks the "block until all previously queued commands have completed" contract in a multi-CPU scenario: CPU2: queue inv-B => need_sync = true CPU1: queue CWAIT(N); need_sync = false; then wait_on_sem(N) CPU2: read need_sync == false => return 0 (no wait!) CPU2 returns without waiting for any sequence number even though its inv-B may not have completed yet (CWAIT(N), queued after inv-B, has not been signaled). CPU2 then proceeds to, for example, free page-table pages while the IOMMU can still walk stale translations, opening a use-after-free window. This is a logical race in the meaning of the flag, not a memory-visibility issue, so barriers alone do not help. Fix it without losing the optimization of avoiding redundant CWAIT commands: take iommu->lock before testing need_sync, and when it is false do not return early but wait for the last allocated sequence number (cmd_sem_val). Since need_sync == false implies no sync command was queued after the last CWAIT, that CWAIT is FIFO-ordered after every not-yet-completed command, so waiting for its sequence number guarantees all prior commands (possibly queued by another CPU) have completed. The common path with pending work is unchanged and no extra hardware command is issued. Signed-off-by: Guanghui Feng Fixes: 815b33fdc279 ("x86/amd-iommu: Cleanup completion-wait handling") Reviewed-by: Vasant Hegde Signed-off-by: Will Deacon Signed-off-by: Sasha Levin

iommu/amd: Fix a stale comment about which legacy mode is user visible

2026-07-24T14:03:00+00:00

[ Upstream commit 4bf53c2d0c08bbdaa32f2114281f1ddab61902bf ] Update a stale comment about which of the legacy modes is visible to the user, i.e. can be forced via amd_iommu_intr=legacy. Fixes: b74aa02d7a30 ("iommu/amd: Fix legacy interrupt remapping for x2APIC-enabled system") Signed-off-by: Sean Christopherson Reviewed-by: Vasant Hegde Reviewed-by: Wei Wang Signed-off-by: Joerg Roedel Signed-off-by: Sasha Levin

iommu, debugobjects: avoid gcc-16.1 section mismatch warnings

2026-06-19T11:39:19+00:00

commit 4c9ad387aa2d6785299722e54224d34764edaeb3 upstream. gcc-16 has gained some more advanced inter-procedual optimization techniques that enable it to inline the dummy_tlb_add_page() and dummy_tlb_flush() function pointers into a specialized version of __arm_v7s_unmap: WARNING: modpost: vmlinux: section mismatch in reference: __arm_v7s_unmap+0x2cc (section: .text) -> dummy_tlb_add_page (section: .init.text) ERROR: modpost: Section mismatches detected. >From what I can tell, the transformation is correct, as this is only called when __arm_v7s_unmap() is called from arm_v7s_do_selftests(), which is also __init. Since __arm_v7s_unmap() however is not __init, gcc cannot inline the inner function calls directly. In debug_objects_selftest(), the same thing happens. Both the caller and the leaf function are __init, but the IPA pulls it into a non-init one: WARNING: modpost: vmlinux: section mismatch in reference: lookup_object_or_alloc+0x7c (section: .text.lookup_object_or_alloc) -> is_static_object (section: .init.text) Marking the affected functions as not "__init" would reliably avoid this issue but is not a good solution because it removes an otherwise correct annotation. I tried marking the functions as 'noinline', but that ended up not covering all the affected configurations. With some more experimenting, I found that marking these functions as __attribute__((noipa)) is both logical and reliable. In order to keep the syntax readable, add a custom macro for this in include/linux/compiler_attributes.h next to other related macros and use it to annotate both files. Link: https://lore.kernel.org/all/abRB6g-48ZX6Yl2r@willie-the-truck/ Cc: Will Deacon Cc: Thomas Gleixner Cc: Andrew Morton Cc: Miguel Ojeda Cc: linux-kbuild@vger.kernel.org Cc: stable@vger.kernel.org Signed-off-by: Arnd Bergmann Acked-by: Will Deacon Acked-by: Thomas Gleixner Acked-by: Miguel Ojeda Signed-off-by: Joerg Roedel Signed-off-by: Greg Kroah-Hartman

iommu/vt-d: Disable DMAR for Intel Q35 IGFX

2026-05-23T11:03:34+00:00

commit 2cda2e10dc8343ae01eae9e999a876b7e7d37861 upstream. Intel Q35 integrated graphics (8086:29b2) exhibits broken DMAR behaviour similar to other G4x/GM45 devices for which DMAR is already disabled via quirks. When DMAR is enabled, the system may hard lock up during boot or early device initialization, requiring a reset. Add the missing PCI ID to the existing quirk list to disable DMAR for this device. Fixes: 1f76249cc3be ("iommu/vt-d: Declare Broadwell igfx dmar support snafu") Cc: stable@vger.kernel.org Closes: https://bugzilla.kernel.org/show_bug.cgi?id=201185 Closes: https://bugzilla.kernel.org/show_bug.cgi?id=216064 Signed-off-by: Naval Alcalá Link: https://lore.kernel.org/r/20260410161622.13549-1-ari@naval.cat Signed-off-by: Lu Baolu Signed-off-by: Joerg Roedel Signed-off-by: Greg Kroah-Hartman

iommufd: vfio compatibility extension check for noiommu mode

2026-05-23T11:03:16+00:00

[ Upstream commit 7147ec874ea08c322d779d8eba28946e294ed1f3 ] VFIO_CHECK_EXTENSION should return false for TYPE1_IOMMU variants when in NO-IOMMU mode and IOMMUFD compat container is set. This change makes the behavior match VFIO_CONTAINER in noiommu mode. It also prevents userspace from incorrectly attempting to use TYPE1 IOMMU operations in a no-iommu context. Fixes: d624d6652a65 ("iommufd: vfio container FD ioctl compatibility") Link: https://patch.msgid.link/r/20260213183636.3340-1-jacob.pan@linux.microsoft.com Signed-off-by: Jacob Pan Signed-off-by: Jason Gunthorpe Signed-off-by: Sasha Levin