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2026-03-04iommu/vt-d: Flush dev-IOTLB only when PCIe device is accessible in scalable modeJinhui Guo1-1/+1
[ Upstream commit 10e60d87813989e20eac1f3eda30b3bae461e7f9 ] Commit 4fc82cd907ac ("iommu/vt-d: Don't issue ATS Invalidation request when device is disconnected") relies on pci_dev_is_disconnected() to skip ATS invalidation for safely-removed devices, but it does not cover link-down caused by faults, which can still hard-lock the system. For example, if a VM fails to connect to the PCIe device, "virsh destroy" is executed to release resources and isolate the fault, but a hard-lockup occurs while releasing the group fd. Call Trace: qi_submit_sync qi_flush_dev_iotlb intel_pasid_tear_down_entry device_block_translation blocking_domain_attach_dev __iommu_attach_device __iommu_device_set_domain __iommu_group_set_domain_internal iommu_detach_group vfio_iommu_type1_detach_group vfio_group_detach_container vfio_group_fops_release __fput Although pci_device_is_present() is slower than pci_dev_is_disconnected(), it still takes only ~70 µs on a ConnectX-5 (8 GT/s, x2) and becomes even faster as PCIe speed and width increase. Besides, devtlb_invalidation_with_pasid() is called only in the paths below, which are far less frequent than memory map/unmap. 1. mm-struct release 2. {attach,release}_dev 3. set/remove PASID 4. dirty-tracking setup The gain in system stability far outweighs the negligible cost of using pci_device_is_present() instead of pci_dev_is_disconnected() to decide when to skip ATS invalidation, especially under GDR high-load conditions. Fixes: 4fc82cd907ac ("iommu/vt-d: Don't issue ATS Invalidation request when device is disconnected") Cc: stable@vger.kernel.org Signed-off-by: Jinhui Guo <guojinhui.liam@bytedance.com> Link: https://lore.kernel.org/r/20251211035946.2071-3-guojinhui.liam@bytedance.com Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-03-04iommu/amd: move wait_on_sem() out of spinlockAnkit Soni1-8/+17
[ Upstream commit d2a0cac10597068567d336e85fa3cbdbe8ca62bf ] With iommu.strict=1, the existing completion wait path can cause soft lockups under stressed environment, as wait_on_sem() busy-waits under the spinlock with interrupts disabled. Move the completion wait in iommu_completion_wait() out of the spinlock. wait_on_sem() only polls the hardware-updated cmd_sem and does not require iommu->lock, so holding the lock during the busy wait unnecessarily increases contention and extends the time with interrupts disabled. Signed-off-by: Ankit Soni <Ankit.Soni@amd.com> Reviewed-by: Vasant Hegde <vasant.hegde@amd.com> Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-03-04iommu/arm-smmu-v3: Improve CMDQ lock fairness and efficiencyAlexander Grest1-10/+21
[ Upstream commit df180b1a4cc51011c5f8c52c7ec02ad2e42962de ] The SMMU CMDQ lock is highly contentious when there are multiple CPUs issuing commands and the queue is nearly full. The lock has the following states: - 0: Unlocked - >0: Shared lock held with count - INT_MIN+N: Exclusive lock held, where N is the # of shared waiters - INT_MIN: Exclusive lock held, no shared waiters When multiple CPUs are polling for space in the queue, they attempt to grab the exclusive lock to update the cons pointer from the hardware. If they fail to get the lock, they will spin until either the cons pointer is updated by another CPU. The current code allows the possibility of shared lock starvation if there is a constant stream of CPUs trying to grab the exclusive lock. This leads to severe latency issues and soft lockups. Consider the following scenario where CPU1's attempt to acquire the shared lock is starved by CPU2 and CPU0 contending for the exclusive lock. CPU0 (exclusive) | CPU1 (shared) | CPU2 (exclusive) | `cmdq->lock` -------------------------------------------------------------------------- trylock() //takes | | | 0 | shared_lock() | | INT_MIN | fetch_inc() | | INT_MIN | no return | | INT_MIN + 1 | spins // VAL >= 0 | | INT_MIN + 1 unlock() | spins... | | INT_MIN + 1 set_release(0) | spins... | | 0 see[NOTE] (done) | (sees 0) | trylock() // takes | 0 | *exits loop* | cmpxchg(0, INT_MIN) | 0 | | *cuts in* | INT_MIN | cmpxchg(0, 1) | | INT_MIN | fails // != 0 | | INT_MIN | spins // VAL >= 0 | | INT_MIN | *starved* | | INT_MIN [NOTE] The current code resets the exclusive lock to 0 regardless of the state of the lock. This causes two problems: 1. It opens the possibility of back-to-back exclusive locks and the downstream effect of starving shared lock. 2. The count of shared lock waiters are lost. To mitigate this, we release the exclusive lock by only clearing the sign bit while retaining the shared lock waiter count as a way to avoid starving the shared lock waiters. Also deleted cmpxchg loop while trying to acquire the shared lock as it is not needed. The waiters can see the positive lock count and proceed immediately after the exclusive lock is released. Exclusive lock is not starved in that submitters will try exclusive lock first when new spaces become available. Reviewed-by: Mostafa Saleh <smostafa@google.com> Reviewed-by: Nicolin Chen <nicolinc@nvidia.com> Signed-off-by: Alexander Grest <Alexander.Grest@microsoft.com> Signed-off-by: Jacob Pan <jacob.pan@linux.microsoft.com> Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-03-04iommu/vt-d: Flush cache for PASID table before using itDmytro Maluka1-3/+4
[ Upstream commit 22d169bdd2849fe6bd18c2643742e1c02be6451c ] When writing the address of a freshly allocated zero-initialized PASID table to a PASID directory entry, do that after the CPU cache flush for this PASID table, not before it, to avoid the time window when this PASID table may be already used by non-coherent IOMMU hardware while its contents in RAM is still some random old data, not zero-initialized. Fixes: 194b3348bdbb ("iommu/vt-d: Fix PASID directory pointer coherency") Signed-off-by: Dmytro Maluka <dmaluka@chromium.org> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Link: https://lore.kernel.org/r/20251221123508.37495-1-dmaluka@chromium.org Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-11Revert "iommu/amd: Skip enabling command/event buffers for kdump"Greg Kroah-Hartman1-19/+9
This reverts commit 44a764aec64b3f3235b9cbac2525222f69685418 which is commit 9be15fbfc6c5c89c22cf6e209f66ea43ee0e58bb upstream. This causes problems in older kernel trees as SNP host kdump is not supported in them, so drop it from the stable branches. Reported-by: Ashish Kalra <ashish.kalra@amd.com> Link: https://lore.kernel.org/r/dacdff7f-0606-4ed5-b056-2de564404d51@amd.com Cc: Vasant Hegde <vasant.hegde@amd.com> Cc: Sairaj Kodilkar <sarunkod@amd.com> Cc: Joerg Roedel <joerg.roedel@amd.com> Cc: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-01-11iommu: disable SVA when CONFIG_X86 is setLu Baolu1-0/+3
commit 72f98ef9a4be30d2a60136dd6faee376f780d06c upstream. Patch series "Fix stale IOTLB entries for kernel address space", v7. This proposes a fix for a security vulnerability related to IOMMU Shared Virtual Addressing (SVA). In an SVA context, an IOMMU can cache kernel page table entries. When a kernel page table page is freed and reallocated for another purpose, the IOMMU might still hold stale, incorrect entries. This can be exploited to cause a use-after-free or write-after-free condition, potentially leading to privilege escalation or data corruption. This solution introduces a deferred freeing mechanism for kernel page table pages, which provides a safe window to notify the IOMMU to invalidate its caches before the page is reused. This patch (of 8): In the IOMMU Shared Virtual Addressing (SVA) context, the IOMMU hardware shares and walks the CPU's page tables. The x86 architecture maps the kernel's virtual address space into the upper portion of every process's page table. Consequently, in an SVA context, the IOMMU hardware can walk and cache kernel page table entries. The Linux kernel currently lacks a notification mechanism for kernel page table changes, specifically when page table pages are freed and reused. The IOMMU driver is only notified of changes to user virtual address mappings. This can cause the IOMMU's internal caches to retain stale entries for kernel VA. Use-After-Free (UAF) and Write-After-Free (WAF) conditions arise when kernel page table pages are freed and later reallocated. The IOMMU could misinterpret the new data as valid page table entries. The IOMMU might then walk into attacker-controlled memory, leading to arbitrary physical memory DMA access or privilege escalation. This is also a Write-After-Free issue, as the IOMMU will potentially continue to write Accessed and Dirty bits to the freed memory while attempting to walk the stale page tables. Currently, SVA contexts are unprivileged and cannot access kernel mappings. However, the IOMMU will still walk kernel-only page tables all the way down to the leaf entries, where it realizes the mapping is for the kernel and errors out. This means the IOMMU still caches these intermediate page table entries, making the described vulnerability a real concern. Disable SVA on x86 architecture until the IOMMU can receive notification to flush the paging cache before freeing the CPU kernel page table pages. Link: https://lkml.kernel.org/r/20251022082635.2462433-1-baolu.lu@linux.intel.com Link: https://lkml.kernel.org/r/20251022082635.2462433-2-baolu.lu@linux.intel.com Fixes: 26b25a2b98e4 ("iommu: Bind process address spaces to devices") Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> Suggested-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Betkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jann Horn <jannh@google.com> Cc: Jean-Philippe Brucker <jean-philippe@linaro.org> Cc: Joerg Roedel <joro@8bytes.org> Cc: Kevin Tian <kevin.tian@intel.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Mike Rapoport <rppt@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Robin Murohy <robin.murphy@arm.com> Cc: Thomas Gleinxer <tglx@linutronix.de> Cc: "Uladzislau Rezki (Sony)" <urezki@gmail.com> Cc: Vasant Hegde <vasant.hegde@amd.com> Cc: Vinicius Costa Gomes <vinicius.gomes@intel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Cc: Yi Lai <yi1.lai@intel.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-01-11iommu/tegra: fix device leak on probe_device()Johan Hovold1-3/+2
commit c08934a61201db8f1d1c66fcc63fb2eb526b656d upstream. Make sure to drop the reference taken to the iommu platform device when looking up its driver data during probe_device(). Note that commit 9826e393e4a8 ("iommu/tegra-smmu: Fix missing put_device() call in tegra_smmu_find") fixed the leak in an error path, but the reference is still leaking on success. Fixes: 891846516317 ("memory: Add NVIDIA Tegra memory controller support") Cc: stable@vger.kernel.org # 3.19: 9826e393e4a8 Cc: Miaoqian Lin <linmq006@gmail.com> Acked-by: Robin Murphy <robin.murphy@arm.com> Acked-by: Thierry Reding <treding@nvidia.com> Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-01-11iommu/sun50i: fix device leak on of_xlate()Johan Hovold1-0/+2
commit f916109bf53864605d10bf6f4215afa023a80406 upstream. Make sure to drop the reference taken to the iommu platform device when looking up its driver data during of_xlate(). Fixes: 4100b8c229b3 ("iommu: Add Allwinner H6 IOMMU driver") Cc: stable@vger.kernel.org # 5.8 Cc: Maxime Ripard <mripard@kernel.org> Acked-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-01-11iommu/qcom: fix device leak on of_xlate()Johan Hovold1-6/+4
commit 6a3908ce56e6879920b44ef136252b2f0c954194 upstream. Make sure to drop the reference taken to the iommu platform device when looking up its driver data during of_xlate(). Note that commit e2eae09939a8 ("iommu/qcom: add missing put_device() call in qcom_iommu_of_xlate()") fixed the leak in a couple of error paths, but the reference is still leaking on success and late failures. Fixes: 0ae349a0f33f ("iommu/qcom: Add qcom_iommu") Cc: stable@vger.kernel.org # 4.14: e2eae09939a8 Cc: Rob Clark <robin.clark@oss.qualcomm.com> Cc: Yu Kuai <yukuai3@huawei.com> Acked-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-01-11iommu/omap: fix device leaks on probe_device()Johan Hovold2-3/+1
commit b5870691065e6bbe6ba0650c0412636c6a239c5a upstream. Make sure to drop the references taken to the iommu platform devices when looking up their driver data during probe_device(). Note that the arch data device pointer added by commit 604629bcb505 ("iommu/omap: add support for late attachment of iommu devices") has never been used. Remove it to underline that the references are not needed. Fixes: 9d5018deec86 ("iommu/omap: Add support to program multiple iommus") Fixes: 7d6827748d54 ("iommu/omap: Fix iommu archdata name for DT-based devices") Cc: stable@vger.kernel.org # 3.18 Cc: Suman Anna <s-anna@ti.com> Acked-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-01-11iommu/mediatek: fix device leak on of_xlate()Johan Hovold1-0/+2
commit b3f1ee18280363ef17f82b564fc379ceba9ec86f upstream. Make sure to drop the reference taken to the iommu platform device when looking up its driver data during of_xlate(). Fixes: 0df4fabe208d ("iommu/mediatek: Add mt8173 IOMMU driver") Cc: stable@vger.kernel.org # 4.6 Acked-by: Robin Murphy <robin.murphy@arm.com> Reviewed-by: Yong Wu <yong.wu@mediatek.com> Signed-off-by: Johan Hovold <johan@kernel.org> Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com> Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-01-11iommu/mediatek-v1: fix device leaks on probe()Johan Hovold1-5/+18
commit 46207625c9f33da0e43bb4ae1e91f0791b6ed633 upstream. Make sure to drop the references taken to the larb devices during probe on probe failure (e.g. probe deferral) and on driver unbind. Fixes: b17336c55d89 ("iommu/mediatek: add support for mtk iommu generation one HW") Cc: stable@vger.kernel.org # 4.8 Cc: Honghui Zhang <honghui.zhang@mediatek.com> Acked-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Johan Hovold <johan@kernel.org> Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com> Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-01-11iommu/mediatek-v1: fix device leak on probe_device()Johan Hovold1-0/+2
commit c77ad28bfee0df9cbc719eb5adc9864462cfb65b upstream. Make sure to drop the reference taken to the iommu platform device when looking up its driver data during probe_device(). Fixes: b17336c55d89 ("iommu/mediatek: add support for mtk iommu generation one HW") Cc: stable@vger.kernel.org # 4.8 Cc: Honghui Zhang <honghui.zhang@mediatek.com> Acked-by: Robin Murphy <robin.murphy@arm.com> Reviewed-by: Yong Wu <yong.wu@mediatek.com> Signed-off-by: Johan Hovold <johan@kernel.org> Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com> Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-01-11iommu/ipmmu-vmsa: fix device leak on of_xlate()Johan Hovold1-0/+2
commit 80aa518452c4aceb9459f9a8e3184db657d1b441 upstream. Make sure to drop the reference taken to the iommu platform device when looking up its driver data during of_xlate(). Fixes: 7b2d59611fef ("iommu/ipmmu-vmsa: Replace local utlb code with fwspec ids") Cc: stable@vger.kernel.org # 4.14 Cc: Magnus Damm <damm+renesas@opensource.se> Acked-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-01-11iommu/exynos: fix device leak on of_xlate()Johan Hovold1-6/+3
commit 05913cc43cb122f9afecdbe775115c058b906e1b upstream. Make sure to drop the reference taken to the iommu platform device when looking up its driver data during of_xlate(). Note that commit 1a26044954a6 ("iommu/exynos: add missing put_device() call in exynos_iommu_of_xlate()") fixed the leak in a couple of error paths, but the reference is still leaking on success. Fixes: aa759fd376fb ("iommu/exynos: Add callback for initializing devices from device tree") Cc: stable@vger.kernel.org # 4.2: 1a26044954a6 Cc: Yu Kuai <yukuai3@huawei.com> Acked-by: Robin Murphy <robin.murphy@arm.com> Acked-by: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-01-11iommu/apple-dart: fix device leak on of_xlate()Johan Hovold1-0/+2
commit a6eaa872c52a181ae9a290fd4e40c9df91166d7a upstream. Make sure to drop the reference taken to the iommu platform device when looking up its driver data during of_xlate(). Fixes: 46d1fb072e76 ("iommu/dart: Add DART iommu driver") Cc: stable@vger.kernel.org # 5.15 Cc: Sven Peter <sven@kernel.org> Acked-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-01-11iommu/amd: Fix pci_segment memleak in alloc_pci_segment()Jinhui Guo1-3/+12
commit 75ba146c2674ba49ed8a222c67f9abfb4a4f2a4f upstream. Fix a memory leak of struct amd_iommu_pci_segment in alloc_pci_segment() when system memory (or contiguous memory) is insufficient. Fixes: 04230c119930 ("iommu/amd: Introduce per PCI segment device table") Fixes: eda797a27795 ("iommu/amd: Introduce per PCI segment rlookup table") Fixes: 99fc4ac3d297 ("iommu/amd: Introduce per PCI segment alias_table") Cc: stable@vger.kernel.org Signed-off-by: Jinhui Guo <guojinhui.liam@bytedance.com> Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-01-11iommu/mediatek: fix use-after-free on probe deferralJohan Hovold1-7/+18
commit de83d4617f9fe059623e97acf7e1e10d209625b5 upstream. The driver is dropping the references taken to the larb devices during probe after successful lookup as well as on errors. This can potentially lead to a use-after-free in case a larb device has not yet been bound to its driver so that the iommu driver probe defers. Fix this by keeping the references as expected while the iommu driver is bound. Fixes: 26593928564c ("iommu/mediatek: Add error path for loop of mm_dts_parse") Cc: stable@vger.kernel.org Cc: Yong Wu <yong.wu@mediatek.com> Acked-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Johan Hovold <johan@kernel.org> Reviewed-by: Yong Wu <yong.wu@mediatek.com> Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com> Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-01-11iommufd/selftest: Check for overflow in IOMMU_TEST_OP_ADD_RESERVEDJason Gunthorpe1-1/+7
[ Upstream commit e6a973af11135439de32ece3b9cbe3bfc043bea8 ] syzkaller found it could overflow math in the test infrastructure and cause a WARN_ON by corrupting the reserved interval tree. This only effects test kernels with CONFIG_IOMMUFD_TEST. Validate the user input length in the test ioctl. Fixes: f4b20bb34c83 ("iommufd: Add kernel support for testing iommufd") Link: https://patch.msgid.link/r/0-v1-cd99f6049ba5+51-iommufd_syz_add_resv_jgg@nvidia.com Reviewed-by: Samiullah Khawaja <skhawaja@google.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Tested-by: Yi Liu <yi.l.liu@intel.com> Reported-by: syzbot+57fdb0cf6a0c5d1f15a2@syzkaller.appspotmail.com Closes: https://lore.kernel.org/all/69368129.a70a0220.38f243.008f.GAE@google.com Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-11iommu/arm-smmu-qcom: Enable use of all SMR groups when running bare-metalStephan Gerhold1-10/+17
[ Upstream commit 5583a55e074b33ccd88ac0542fd7cd656a7e2c8c ] Some platforms (e.g. SC8280XP and X1E) support more than 128 stream matching groups. This is more than what is defined as maximum by the ARM SMMU architecture specification. Commit 122611347326 ("iommu/arm-smmu-qcom: Limit the SMR groups to 128") disabled use of the additional groups because they don't exhibit the same behavior as the architecture supported ones. It seems like this is just another quirk of the hypervisor: When running bare-metal without the hypervisor, the additional groups appear to behave just like all others. The boot firmware uses some of the additional groups, so ignoring them in this situation leads to stream match conflicts whenever we allocate a new SMR group for the same SID. The workaround exists primarily because the bypass quirk detection fails when using a S2CR register from the additional matching groups, so let's perform the test with the last reliable S2CR (127) and then limit the number of SMR groups only if we detect that we are running below the hypervisor (because of the bypass quirk). Fixes: 122611347326 ("iommu/arm-smmu-qcom: Limit the SMR groups to 128") Signed-off-by: Stephan Gerhold <stephan.gerhold@linaro.org> Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-11-24iommufd: Make vfio_compat's unmap succeed if the range is already emptyJason Gunthorpe2-9/+7
[ Upstream commit afb47765f9235181fddc61c8633b5a8cfae29fd2 ] iommufd returns ENOENT when attempting to unmap a range that is already empty, while vfio type1 returns success. Fix vfio_compat to match. Fixes: d624d6652a65 ("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> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-11-24iommu/vt-d: Replace snprintf with scnprintf in dmar_latency_snapshot()Seyediman Seyedarab3-17/+8
[ Upstream commit 75c02a037609f34db17e91be195cedb33b61bae0 ] 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> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-11-24iommu/apple-dart: Clear stream error indicator bits for T8110 DARTsHector Martin1-0/+5
[ Upstream commit ecf6508923f87e4597228f70cc838af3d37f6662 ] 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> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-11-24iommu/amd: Skip enabling command/event buffers for kdumpAshish Kalra1-9/+19
[ Upstream commit 9be15fbfc6c5c89c22cf6e209f66ea43ee0e58bb ] 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> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-10-19iommu/vt-d: PRS isn't usable if PDS isn't supportedLu Baolu1-1/+1
commit 5ef7e24c742038a5d8c626fdc0e3a21834358341 upstream. 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: 66ac4db36f4c ("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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-09-25iommu/amd/pgtbl: Fix possible race while increase page table levelVasant Hegde2-4/+23
[ Upstream commit 1e56310b40fd2e7e0b9493da9ff488af145bdd0c ] 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: 754265bcab7 ("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> [ Adapted pgtable->mode and pgtable->root to use domain->iop.mode and domain->iop.root ] Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-09-25iommu/vt-d: Fix __domain_mapping()'s usage of switch_to_super_page()Eugene Koira1-1/+6
commit dce043c07ca1ac19cfbe2844a6dc71e35c322353 upstream. 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: 9906b9352a35 ("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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-28iommu/amd: Avoid stack buffer overflow from kernel cmdlineKees Cook1-2/+2
[ Upstream commit 8503d0fcb1086a7cfe26df67ca4bd9bd9e99bdec ] While the kernel command line is considered trusted in most environments, avoid writing 1 byte past the end of "acpiid" if the "str" argument is maximum length. Reported-by: Simcha Kosman <simcha.kosman@cyberark.com> Closes: https://lore.kernel.org/all/AS8P193MB2271C4B24BCEDA31830F37AE84A52@AS8P193MB2271.EURP193.PROD.OUTLOOK.COM Fixes: b6b26d86c61c ("iommu/amd: Add a length limitation for the ivrs_acpihid command-line parameter") Signed-off-by: Kees Cook <kees@kernel.org> Reviewed-by: Ankit Soni <Ankit.Soni@amd.com> Link: https://lore.kernel.org/r/20250804154023.work.970-kees@kernel.org Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-08-28iommufd: Prevent ALIGN() overflowJason Gunthorpe1-16/+25
commit b42497e3c0e74db061eafad41c0cd7243c46436b upstream. When allocating IOVA the candidate range gets aligned to the target alignment. If the range is close to ULONG_MAX then the ALIGN() can wrap resulting in a corrupted iova. Open code the ALIGN() using get_add_overflow() to prevent this. This simplifies the checks as we don't need to check for length earlier either. Consolidate the two copies of this code under a single helper. This bug would allow userspace to create a mapping that overlaps with some other mapping or a reserved range. Cc: stable@vger.kernel.org Fixes: 51fe6141f0f6 ("iommufd: Data structure to provide IOVA to PFN mapping") Reported-by: syzbot+c2f65e2801743ca64e08@syzkaller.appspotmail.com Closes: https://lore.kernel.org/r/685af644.a00a0220.2e5631.0094.GAE@google.com Reviewed-by: Yi Liu <yi.l.liu@intel.com> Reviewed-by: Nicolin Chen <nicolinc@nvidia.com> Link: https://patch.msgid.link/all/1-v1-7b4a16fc390b+10f4-iommufd_alloc_overflow_jgg@nvidia.com/ Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-28iommufd: Report unmapped bytes in the error path of iopt_unmap_iova_rangeNicolin Chen1-2/+5
commit b23e09f9997771b4b739c1c694fa832b5fa2de02 upstream. There are callers that read the unmapped bytes even when rc != 0. Thus, do not forget to report it in the error path too. Fixes: 8d40205f6093 ("iommufd: Add kAPI toward external drivers for kernel access") Link: https://patch.msgid.link/r/e2b61303bbc008ba1a4e2d7c2a2894749b59fdac.1752126748.git.nicolinc@nvidia.com Cc: stable@vger.kernel.org Reviewed-by: Kevin Tian <kevin.tian@intel.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Nicolin Chen <nicolinc@nvidia.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-28iommu/arm-smmu-qcom: Add SM6115 MDSS compatibleAlexey Klimov1-0/+1
commit f7fa8520f30373ce99c436c4d57c76befdacbef3 upstream. Add the SM6115 MDSS compatible to clients compatible list, as it also needs that workaround. Without this workaround, for example, QRB4210 RB2 which is based on SM4250/SM6115 generates a lot of smmu unhandled context faults during boot: arm_smmu_context_fault: 116854 callbacks suppressed arm-smmu c600000.iommu: Unhandled context fault: fsr=0x402, iova=0x5c0ec600, fsynr=0x320021, cbfrsynra=0x420, cb=5 arm-smmu c600000.iommu: FSR = 00000402 [Format=2 TF], SID=0x420 arm-smmu c600000.iommu: FSYNR0 = 00320021 [S1CBNDX=50 PNU PLVL=1] arm-smmu c600000.iommu: Unhandled context fault: fsr=0x402, iova=0x5c0d7800, fsynr=0x320021, cbfrsynra=0x420, cb=5 arm-smmu c600000.iommu: FSR = 00000402 [Format=2 TF], SID=0x420 and also failed initialisation of lontium lt9611uxc, gpu and dpu is observed: (binding MDSS components triggered by lt9611uxc have failed) ------------[ cut here ]------------ !aspace WARNING: CPU: 6 PID: 324 at drivers/gpu/drm/msm/msm_gem_vma.c:130 msm_gem_vma_init+0x150/0x18c [msm] Modules linked in: ... (long list of modules) CPU: 6 UID: 0 PID: 324 Comm: (udev-worker) Not tainted 6.15.0-03037-gaacc73ceeb8b #4 PREEMPT Hardware name: Qualcomm Technologies, Inc. QRB4210 RB2 (DT) pstate: 80000005 (Nzcv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : msm_gem_vma_init+0x150/0x18c [msm] lr : msm_gem_vma_init+0x150/0x18c [msm] sp : ffff80008144b280 ... Call trace: msm_gem_vma_init+0x150/0x18c [msm] (P) get_vma_locked+0xc0/0x194 [msm] msm_gem_get_and_pin_iova_range+0x4c/0xdc [msm] msm_gem_kernel_new+0x48/0x160 [msm] msm_gpu_init+0x34c/0x53c [msm] adreno_gpu_init+0x1b0/0x2d8 [msm] a6xx_gpu_init+0x1e8/0x9e0 [msm] adreno_bind+0x2b8/0x348 [msm] component_bind_all+0x100/0x230 msm_drm_bind+0x13c/0x3d0 [msm] try_to_bring_up_aggregate_device+0x164/0x1d0 __component_add+0xa4/0x174 component_add+0x14/0x20 dsi_dev_attach+0x20/0x34 [msm] dsi_host_attach+0x58/0x98 [msm] devm_mipi_dsi_attach+0x34/0x90 lt9611uxc_attach_dsi.isra.0+0x94/0x124 [lontium_lt9611uxc] lt9611uxc_probe+0x540/0x5fc [lontium_lt9611uxc] i2c_device_probe+0x148/0x2a8 really_probe+0xbc/0x2c0 __driver_probe_device+0x78/0x120 driver_probe_device+0x3c/0x154 __driver_attach+0x90/0x1a0 bus_for_each_dev+0x68/0xb8 driver_attach+0x24/0x30 bus_add_driver+0xe4/0x208 driver_register+0x68/0x124 i2c_register_driver+0x48/0xcc lt9611uxc_driver_init+0x20/0x1000 [lontium_lt9611uxc] do_one_initcall+0x60/0x1d4 do_init_module+0x54/0x1fc load_module+0x1748/0x1c8c init_module_from_file+0x74/0xa0 __arm64_sys_finit_module+0x130/0x2f8 invoke_syscall+0x48/0x104 el0_svc_common.constprop.0+0xc0/0xe0 do_el0_svc+0x1c/0x28 el0_svc+0x2c/0x80 el0t_64_sync_handler+0x10c/0x138 el0t_64_sync+0x198/0x19c ---[ end trace 0000000000000000 ]--- msm_dpu 5e01000.display-controller: [drm:msm_gpu_init [msm]] *ERROR* could not allocate memptrs: -22 msm_dpu 5e01000.display-controller: failed to load adreno gpu platform a400000.remoteproc:glink-edge:apr:service@7:dais: Adding to iommu group 19 msm_dpu 5e01000.display-controller: failed to bind 5900000.gpu (ops a3xx_ops [msm]): -22 msm_dpu 5e01000.display-controller: adev bind failed: -22 lt9611uxc 0-002b: failed to attach dsi to host lt9611uxc 0-002b: probe with driver lt9611uxc failed with error -22 Suggested-by: Bjorn Andersson <andersson@kernel.org> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com> Fixes: 3581b7062cec ("drm/msm/disp/dpu1: add support for display on SM6115") Cc: stable@vger.kernel.org Signed-off-by: Alexey Klimov <alexey.klimov@linaro.org> Link: https://lore.kernel.org/r/20250613173238.15061-1-alexey.klimov@linaro.org Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-15iommu/amd: Fix geometry.aperture_end for V2 tablesJason Gunthorpe1-2/+15
[ Upstream commit 8637afa79cfa6123f602408cfafe8c9a73620ff1 ] The AMD IOMMU documentation seems pretty clear that the V2 table follows the normal CPU expectation of sign extension. This is shown in Figure 25: AMD64 Long Mode 4-Kbyte Page Address Translation Where bits Sign-Extend [63:57] == [56]. This is typical for x86 which would have three regions in the page table: lower, non-canonical, upper. The manual describes that the V1 table does not sign extend in section 2.2.4 Sharing AMD64 Processor and IOMMU Page Tables GPA-to-SPA Further, Vasant has checked this and indicates the HW has an addtional behavior that the manual does not yet describe. The AMDv2 table does not have the sign extended behavior when attached to PASID 0, which may explain why this has gone unnoticed. The iommu domain geometry does not directly support sign extended page tables. The driver should report only one of the lower/upper spaces. Solve this by removing the top VA bit from the geometry to use only the lower space. This will also make the iommu_domain work consistently on all PASID 0 and PASID != 1. Adjust dma_max_address() to remove the top VA bit. It now returns: 5 Level: Before 0x1ffffffffffffff After 0x0ffffffffffffff 4 Level: Before 0xffffffffffff After 0x7fffffffffff Fixes: 11c439a19466 ("iommu/amd/pgtbl_v2: Fix domain max address") Link: https://lore.kernel.org/all/8858d4d6-d360-4ef0-935c-bfd13ea54f42@amd.com/ Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Vasant Hegde <vasant.hegde@amd.com> Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com> Link: https://lore.kernel.org/r/0-v2-0615cc99b88a+1ce-amdv2_geo_jgg@nvidia.com Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-07-10iommu/rockchip: prevent iommus dead loop when two masters share one IOMMUSimon Xue1-1/+2
commit 62e062a29ad5133f67c20b333ba0a952a99161ae upstream. When two masters share an IOMMU, calling ops->of_xlate during the second master's driver init may overwrite iommu->domain set by the first. This causes the check if (iommu->domain == domain) in rk_iommu_attach_device() to fail, resulting in the same iommu->node being added twice to &rk_domain->iommus, which can lead to an infinite loop in subsequent &rk_domain->iommus operations. Cc: <stable@vger.kernel.org> Fixes: 25c2325575cc ("iommu/rockchip: Add missing set_platform_dma_ops callback") Signed-off-by: Simon Xue <xxm@rock-chips.com> Reviewed-by: Robin Murphy <robin.murphy@arm.com> Link: https://lore.kernel.org/r/20250623020018.584802-1-xxm@rock-chips.com Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-06-27iommu/amd: Ensure GA log notifier callbacks finish running before module unloadSean Christopherson1-0/+8
[ Upstream commit 94c721ea03c7078163f41dbaa101ac721ddac329 ] Synchronize RCU when unregistering KVM's GA log notifier to ensure all in-flight interrupt handlers complete before KVM-the module is unloaded. Signed-off-by: Sean Christopherson <seanjc@google.com> Link: https://lore.kernel.org/r/20250315031048.2374109-1-seanjc@google.com Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-06-19iommu: remove duplicate selection of DMAR_TABLERolf Eike Beer1-1/+0
[ Upstream commit 9548feff840a05d61783e6316d08ed37e115f3b1 ] This is already done in intel/Kconfig. Fixes: 70bad345e622 ("iommu: Fix compilation without CONFIG_IOMMU_INTEL") Signed-off-by: Rolf Eike Beer <eb@emlix.com> Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com> Link: https://lore.kernel.org/r/2232605.Mh6RI2rZIc@devpool92.emlix.com Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-06-19iommu: Protect against overflow in iommu_pgsize()Jason Gunthorpe1-1/+3
[ Upstream commit e586e22974d2b7acbef3c6c3e01b2d5ce69efe33 ] 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: b1d99dc5f983 ("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> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-06-04genirq/msi: Store the IOMMU IOVA directly in msi_desc instead of iommu_cookieJason Gunthorpe1-15/+13
[ Upstream commit 1f7df3a691740a7736bbc99dc4ed536120eb4746 ] The IOMMU translation for MSI message addresses has been a 2-step process, separated in time: 1) iommu_dma_prepare_msi(): A cookie pointer containing the IOVA address is stored in the MSI descriptor when an MSI interrupt is allocated. 2) iommu_dma_compose_msi_msg(): this cookie pointer is used to compute a translated message address. This has an inherent lifetime problem for the pointer stored in the cookie that must remain valid between the two steps. However, there is no locking at the irq layer that helps protect the lifetime. Today, this works under the assumption that the iommu domain is not changed while MSI interrupts being programmed. This is true for normal DMA API users within the kernel, as the iommu domain is attached before the driver is probed and cannot be changed while a driver is attached. Classic VFIO type1 also prevented changing the iommu domain while VFIO was running as it does not support changing the "container" after starting up. However, iommufd has improved this so that the iommu domain can be changed during VFIO operation. This potentially allows userspace to directly race VFIO_DEVICE_ATTACH_IOMMUFD_PT (which calls iommu_attach_group()) and VFIO_DEVICE_SET_IRQS (which calls into iommu_dma_compose_msi_msg()). This potentially causes both the cookie pointer and the unlocked call to iommu_get_domain_for_dev() on the MSI translation path to become UAFs. Fix the MSI cookie UAF by removing the cookie pointer. The translated IOVA address is already known during iommu_dma_prepare_msi() and cannot change. Thus, it can simply be stored as an integer in the MSI descriptor. The other UAF related to iommu_get_domain_for_dev() will be addressed in patch "iommu: Make iommu_dma_prepare_msi() into a generic operation" by using the IOMMU group mutex. Link: https://patch.msgid.link/r/a4f2cd76b9dc1833ee6c1cf325cba57def22231c.1740014950.git.nicolinc@nvidia.com Signed-off-by: Nicolin Chen <nicolinc@nvidia.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-06-04iommu/amd/pgtbl_v2: Improve error handlingVasant Hegde1-1/+1
[ Upstream commit 36a1cfd497435ba5e37572fe9463bb62a7b1b984 ] Return -ENOMEM if v2_alloc_pte() fails to allocate memory. Signed-off-by: Vasant Hegde <vasant.hegde@amd.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Link: https://lore.kernel.org/r/20250227162320.5805-4-vasant.hegde@amd.com Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-05-09iommu/arm-smmu-v3: Fix iommu_device_probe bug due to duplicated stream idsNicolin Chen1-4/+15
[ Upstream commit b00d24997a11c10d3e420614f0873b83ce358a34 ] ASPEED VGA card has two built-in devices: 0008:06:00.0 PCI bridge: ASPEED Technology, Inc. AST1150 PCI-to-PCI Bridge (rev 06) 0008:07:00.0 VGA compatible controller: ASPEED Technology, Inc. ASPEED Graphics Family (rev 52) Its toplogy looks like this: +-[0008:00]---00.0-[01-09]--+-00.0-[02-09]--+-00.0-[03]----00.0 Sandisk Corp Device 5017 | +-01.0-[04]-- | +-02.0-[05]----00.0 NVIDIA Corporation Device | +-03.0-[06-07]----00.0-[07]----00.0 ASPEED Technology, Inc. ASPEED Graphics Family | +-04.0-[08]----00.0 Renesas Technology Corp. uPD720201 USB 3.0 Host Controller | \-05.0-[09]----00.0 Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller \-00.1 PMC-Sierra Inc. Device 4028 The IORT logic populaties two identical IDs into the fwspec->ids array via DMA aliasing in iort_pci_iommu_init() called by pci_for_each_dma_alias(). Though the SMMU driver had been able to handle this situation since commit 563b5cbe334e ("iommu/arm-smmu-v3: Cope with duplicated Stream IDs"), that got broken by the later commit cdf315f907d4 ("iommu/arm-smmu-v3: Maintain a SID->device structure"), which ended up with allocating separate streams with the same stuffing. On a kernel prior to v6.15-rc1, there has been an overlooked warning: pci 0008:07:00.0: vgaarb: setting as boot VGA device pci 0008:07:00.0: vgaarb: bridge control possible pci 0008:07:00.0: vgaarb: VGA device added: decodes=io+mem,owns=none,locks=none pcieport 0008:06:00.0: Adding to iommu group 14 ast 0008:07:00.0: stream 67328 already in tree <===== WARNING ast 0008:07:00.0: enabling device (0002 -> 0003) ast 0008:07:00.0: Using default configuration ast 0008:07:00.0: AST 2600 detected ast 0008:07:00.0: [drm] Using analog VGA ast 0008:07:00.0: [drm] dram MCLK=396 Mhz type=1 bus_width=16 [drm] Initialized ast 0.1.0 for 0008:07:00.0 on minor 0 ast 0008:07:00.0: [drm] fb0: astdrmfb frame buffer device With v6.15-rc, since the commit bcb81ac6ae3c ("iommu: Get DT/ACPI parsing into the proper probe path"), the error returned with the warning is moved to the SMMU device probe flow: arm_smmu_probe_device+0x15c/0x4c0 __iommu_probe_device+0x150/0x4f8 probe_iommu_group+0x44/0x80 bus_for_each_dev+0x7c/0x100 bus_iommu_probe+0x48/0x1a8 iommu_device_register+0xb8/0x178 arm_smmu_device_probe+0x1350/0x1db0 which then fails the entire SMMU driver probe: pci 0008:06:00.0: Adding to iommu group 21 pci 0008:07:00.0: stream 67328 already in tree arm-smmu-v3 arm-smmu-v3.9.auto: Failed to register iommu arm-smmu-v3 arm-smmu-v3.9.auto: probe with driver arm-smmu-v3 failed with error -22 Since SMMU driver had been already expecting a potential duplicated Stream ID in arm_smmu_install_ste_for_dev(), change the arm_smmu_insert_master() routine to ignore a duplicated ID from the fwspec->sids array as well. Note: this has been failing the iommu_device_probe() since 2021, although a recent iommu commit in v6.15-rc1 that moves iommu_device_probe() started to fail the SMMU driver probe. Since nobody has cared about DMA Alias support, leave that as it was but fix the fundamental iommu_device_probe() breakage. Fixes: cdf315f907d4 ("iommu/arm-smmu-v3: Maintain a SID->device structure") Cc: stable@vger.kernel.org Suggested-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Nicolin Chen <nicolinc@nvidia.com> Link: https://lore.kernel.org/r/20250415185620.504299-1-nicolinc@nvidia.com Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-05-09iommu/arm-smmu-v3: Use the new rb tree helpersJason Gunthorpe1-37/+31
[ Upstream commit a2bb820e862d61f9ca1499e500915f9f505a2655 ] Since v5.12 the rbtree has gained some simplifying helpers aimed at making rb tree users write less convoluted boiler plate code. Instead the caller provides a single comparison function and the helpers generate the prior open-coded stuff. Update smmu->streams to use rb_find_add() and rb_find(). Tested-by: Nicolin Chen <nicolinc@nvidia.com> Reviewed-by: Mostafa Saleh <smostafa@google.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Link: https://lore.kernel.org/r/1-v3-9fef8cdc2ff6+150d1-smmuv3_tidy_jgg@nvidia.com Signed-off-by: Will Deacon <will@kernel.org> Stable-dep-of: b00d24997a11 ("iommu/arm-smmu-v3: Fix iommu_device_probe bug due to duplicated stream ids") Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-05-09iommu: Handle race with default domain setupRobin Murphy1-0/+18
commit b46064a18810bad3aea089a79993ca5ea7a3d2b2 upstream. It turns out that deferred default domain creation leaves a subtle race window during iommu_device_register() wherein a client driver may asynchronously probe in parallel and get as far as performing DMA API operations with dma-direct, only to be switched to iommu-dma underfoot once the default domain attachment finally happens, with obviously disastrous consequences. Even the wonky of_iommu_configure() path is at risk, since iommu_fwspec_init() will no longer defer client probe as the instance ops are (necessarily) already registered, and the "replay" iommu_probe_device() call can see dev->iommu_group already set and so think there's nothing to do either. Fortunately we already have the right tool in the right place in the form of iommu_device_use_default_domain(), which just needs to ensure that said default domain is actually ready to *be* used. Deferring the client probe shouldn't have too much impact, given that this only happens while the IOMMU driver is probing, and thus due to kick the deferred probe list again once it finishes. Reported-by: Charan Teja Kalla <quic_charante@quicinc.com> Fixes: 98ac73f99bc4 ("iommu: Require a default_domain for all iommu drivers") Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Robin Murphy <robin.murphy@arm.com> Link: https://lore.kernel.org/r/e88b94c9b575034a2c98a48b3d383654cbda7902.1740753261.git.robin.murphy@arm.com Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Robin Murphy <robin.murphy@arm.com>
2025-05-09iommu/vt-d: Apply quirk_iommu_igfx for 8086:0044 (QM57/QS57)Mingcong Bai1-1/+3
commit 2c8a7c66c90832432496616a9a3c07293f1364f3 upstream. On the Lenovo ThinkPad X201, when Intel VT-d is enabled in the BIOS, the kernel boots with errors related to DMAR, the graphical interface appeared quite choppy, and the system resets erratically within a minute after it booted: DMAR: DRHD: handling fault status reg 3 DMAR: [DMA Write NO_PASID] Request device [00:02.0] fault addr 0xb97ff000 [fault reason 0x05] PTE Write access is not set Upon comparing boot logs with VT-d on/off, I found that the Intel Calpella quirk (`quirk_calpella_no_shadow_gtt()') correctly applied the igfx IOMMU disable/quirk correctly: pci 0000:00:00.0: DMAR: BIOS has allocated no shadow GTT; disabling IOMMU for graphics Whereas with VT-d on, it went into the "else" branch, which then triggered the DMAR handling fault above: ... else if (!disable_igfx_iommu) { /* we have to ensure the gfx device is idle before we flush */ pci_info(dev, "Disabling batched IOTLB flush on Ironlake\n"); iommu_set_dma_strict(); } Now, this is not exactly scientific, but moving 0x0044 to quirk_iommu_igfx seems to have fixed the aforementioned issue. Running a few `git blame' runs on the function, I have found that the quirk was originally introduced as a fix specific to ThinkPad X201: commit 9eecabcb9a92 ("intel-iommu: Abort IOMMU setup for igfx if BIOS gave no shadow GTT space") Which was later revised twice to the "else" branch we saw above: - 2011: commit 6fbcfb3e467a ("intel-iommu: Workaround IOTLB hang on Ironlake GPU") - 2024: commit ba00196ca41c ("iommu/vt-d: Decouple igfx_off from graphic identity mapping") I'm uncertain whether further testings on this particular laptops were done in 2011 and (honestly I'm not sure) 2024, but I would be happy to do some distro-specific testing if that's what would be required to verify this patch. P.S., I also see IDs 0x0040, 0x0062, and 0x006a listed under the same `quirk_calpella_no_shadow_gtt()' quirk, but I'm not sure how similar these chipsets are (if they share the same issue with VT-d or even, indeed, if this issue is specific to a bug in the Lenovo BIOS). With regards to 0x0062, it seems to be a Centrino wireless card, but not a chipset? I have also listed a couple (distro and kernel) bug reports below as references (some of them are from 7-8 years ago!), as they seem to be similar issue found on different Westmere/Ironlake, Haswell, and Broadwell hardware setups. Cc: stable@vger.kernel.org Fixes: 6fbcfb3e467a ("intel-iommu: Workaround IOTLB hang on Ironlake GPU") Fixes: ba00196ca41c ("iommu/vt-d: Decouple igfx_off from graphic identity mapping") Link: https://groups.google.com/g/qubes-users/c/4NP4goUds2c?pli=1 Link: https://bugs.archlinux.org/task/65362 Link: https://bbs.archlinux.org/viewtopic.php?id=230323 Reported-by: Wenhao Sun <weiguangtwk@outlook.com> Closes: https://bugzilla.kernel.org/show_bug.cgi?id=197029 Signed-off-by: Mingcong Bai <jeffbai@aosc.io> Link: https://lore.kernel.org/r/20250415133330.12528-1-jeffbai@aosc.io Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-05-09iommu/amd: Fix potential buffer overflow in parse_ivrs_acpihidPavel Paklov1-0/+8
commit 8dee308e4c01dea48fc104d37f92d5b58c50b96c upstream. There is a string parsing logic error which can lead to an overflow of hid or uid buffers. Comparing ACPIID_LEN against a total string length doesn't take into account the lengths of individual hid and uid buffers so the check is insufficient in some cases. For example if the length of hid string is 4 and the length of the uid string is 260, the length of str will be equal to ACPIID_LEN + 1 but uid string will overflow uid buffer which size is 256. The same applies to the hid string with length 13 and uid string with length 250. Check the length of hid and uid strings separately to prevent buffer overflow. Found by Linux Verification Center (linuxtesting.org) with SVACE. Fixes: ca3bf5d47cec ("iommu/amd: Introduces ivrs_acpihid kernel parameter") Cc: stable@vger.kernel.org Signed-off-by: Pavel Paklov <Pavel.Paklov@cyberprotect.ru> Link: https://lore.kernel.org/r/20250325092259.392844-1-Pavel.Paklov@cyberprotect.ru Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-05-02iommu/amd: Return an error if vCPU affinity is set for non-vCPU IRTESean Christopherson1-1/+1
[ Upstream commit 07172206a26dcf3f0bf7c3ecaadd4242b008ea54 ] Return -EINVAL instead of success if amd_ir_set_vcpu_affinity() is invoked without use_vapic; lying to KVM about whether or not the IRTE was configured to post IRQs is all kinds of bad. Fixes: d98de49a53e4 ("iommu/amd: Enable vAPIC interrupt remapping mode by default") Signed-off-by: Sean Christopherson <seanjc@google.com> Message-ID: <20250404193923.1413163-6-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-04-25iommufd: Fail replace if device has not been attachedYi Liu1-0/+16
commit 55c85fa7579dc2e3f5399ef5bad67a44257c1a48 upstream. The current implementation of iommufd_device_do_replace() implicitly assumes that the input device has already been attached. However, there is no explicit check to verify this assumption. If another device within the same group has been attached, the replace operation might succeed, but the input device itself may not have been attached yet. As a result, the input device might not be tracked in the igroup->device_list, and its reserved IOVA might not be added. Despite this, the caller might incorrectly assume that the device has been successfully replaced, which could lead to unexpected behavior or errors. To address this issue, add a check to ensure that the input device has been attached before proceeding with the replace operation. This check will help maintain the integrity of the device tracking system and prevent potential issues arising from incorrect assumptions about the device's attachment status. Fixes: e88d4ec154a8 ("iommufd: Add iommufd_device_replace()") Link: https://patch.msgid.link/r/20250306034842.5950-1-yi.l.liu@intel.com Cc: stable@vger.kernel.org Reviewed-by: Kevin Tian <kevin.tian@intel.com> Signed-off-by: Yi Liu <yi.l.liu@intel.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-04-25iommufd: Fix uninitialized rc in iommufd_access_rw()Nicolin Chen1-1/+1
commit a05df03a88bc1088be8e9d958f208d6484691e43 upstream. Reported by smatch: drivers/iommu/iommufd/device.c:1392 iommufd_access_rw() error: uninitialized symbol 'rc'. Fixes: 8d40205f6093 ("iommufd: Add kAPI toward external drivers for kernel access") Link: https://patch.msgid.link/r/20250227200729.85030-1-nicolinc@nvidia.com Cc: stable@vger.kernel.org Reported-by: kernel test robot <lkp@intel.com> Reported-by: Dan Carpenter <error27@gmail.com> Closes: https://lore.kernel.org/r/202502271339.a2nWr9UA-lkp@intel.com/ [nicolinc: can't find an original report but only in "old smatch warnings"] Signed-off-by: Nicolin Chen <nicolinc@nvidia.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-04-25iommu/mediatek: Fix NULL pointer deference in mtk_iommu_device_groupLouis-Alexis Eyraud1-13/+13
[ Upstream commit 38e8844005e6068f336a3ad45451a562a0040ca1 ] Currently, mtk_iommu calls during probe iommu_device_register before the hw_list from driver data is initialized. Since iommu probing issue fix, it leads to NULL pointer dereference in mtk_iommu_device_group when hw_list is accessed with list_first_entry (not null safe). So, change the call order to ensure iommu_device_register is called after the driver data are initialized. Fixes: 9e3a2a643653 ("iommu/mediatek: Adapt sharing and non-sharing pgtable case") Fixes: bcb81ac6ae3c ("iommu: Get DT/ACPI parsing into the proper probe path") Reviewed-by: Yong Wu <yong.wu@mediatek.com> Tested-by: Chen-Yu Tsai <wenst@chromium.org> # MT8183 Juniper, MT8186 Tentacruel Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com> Tested-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com> Signed-off-by: Louis-Alexis Eyraud <louisalexis.eyraud@collabora.com> Link: https://lore.kernel.org/r/20250403-fix-mtk-iommu-error-v2-1-fe8b18f8b0a8@collabora.com Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-02-17iommu/arm-smmu-v3: Clean up more on probe failureRobin Murphy1-5/+12
[ Upstream commit fcbd621567420b3a2f21f49bbc056de8b273c625 ] kmemleak noticed that the iopf queue allocated deep down within arm_smmu_init_structures() can be leaked by a subsequent error return from arm_smmu_device_probe(). Furthermore, after arm_smmu_device_reset() we will also leave the SMMU enabled with an empty Stream Table, silently blocking all DMA. This proves rather annoying for debugging said probe failure, so let's handle it a bit better by putting the SMMU back into (more or less) the same state as if it hadn't probed at all. Signed-off-by: Robin Murphy <robin.murphy@arm.com> Link: https://lore.kernel.org/r/5137901958471cf67f2fad5c2229f8a8f1ae901a.1733406914.git.robin.murphy@arm.com Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-02-17iommu/arm-smmu-qcom: add sdm670 adreno iommu compatibleRichard Acayan1-0/+1
[ Upstream commit 42314738906380cbd3b6e9caf3ad34e1b2d66035 ] Add the compatible for the separate IOMMU on SDM670 for the Adreno GPU. This IOMMU has the compatible strings: "qcom,sdm670-smmu-v2", "qcom,adreno-smmu", "qcom,smmu-v2" While the SMMU 500 doesn't need an entry for this specific SoC, the SMMU v2 compatible should have its own entry, as the fallback entry in arm-smmu.c handles "qcom,smmu-v2" without per-process page table support unless there is an entry here. This entry can't be the "qcom,adreno-smmu" compatible because dedicated GPU IOMMUs can also be SMMU 500 with different handling. Signed-off-by: Richard Acayan <mailingradian@gmail.com> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> Link: https://lore.kernel.org/r/20241114004713.42404-6-mailingradian@gmail.com Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-12-14iommu/arm-smmu: Defer probe of clients after smmu device boundPratyush Brahma1-0/+11
commit 229e6ee43d2a160a1592b83aad620d6027084aad upstream. Null pointer dereference occurs due to a race between smmu driver probe and client driver probe, when of_dma_configure() for client is called after the iommu_device_register() for smmu driver probe has executed but before the driver_bound() for smmu driver has been called. Following is how the race occurs: T1:Smmu device probe T2: Client device probe really_probe() arm_smmu_device_probe() iommu_device_register() really_probe() platform_dma_configure() of_dma_configure() of_dma_configure_id() of_iommu_configure() iommu_probe_device() iommu_init_device() arm_smmu_probe_device() arm_smmu_get_by_fwnode() driver_find_device_by_fwnode() driver_find_device() next_device() klist_next() /* null ptr assigned to smmu */ /* null ptr dereference while smmu->streamid_mask */ driver_bound() klist_add_tail() When this null smmu pointer is dereferenced later in arm_smmu_probe_device, the device crashes. Fix this by deferring the probe of the client device until the smmu device has bound to the arm smmu driver. Fixes: 021bb8420d44 ("iommu/arm-smmu: Wire up generic configuration support") Cc: stable@vger.kernel.org Co-developed-by: Prakash Gupta <quic_guptap@quicinc.com> Signed-off-by: Prakash Gupta <quic_guptap@quicinc.com> Signed-off-by: Pratyush Brahma <quic_pbrahma@quicinc.com> Link: https://lore.kernel.org/r/20241004090428.2035-1-quic_pbrahma@quicinc.com [will: Add comment] Signed-off-by: Will Deacon <will@kernel.org> [rm: backport for context conflict prior to 6.8] Signed-off-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>