kernel/linux.git/drivers/iommu/amd, branch v5.10.257

Revert "iommu/amd: Skip enabling command/event buffers for kdump"

2026-01-19T12:12:07+00:00

This reverts commit 30e91eeb0bc9b3daf402b26176d1d52c29ab53e4 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 Link: https://lore.kernel.org/r/dacdff7f-0606-4ed5-b056-2de564404d51@amd.com Cc: Vasant Hegde Cc: Sairaj Kodilkar Cc: Joerg Roedel Cc: Sasha Levin Signed-off-by: Greg Kroah-Hartman

iommu/amd: Skip enabling command/event buffers for kdump

2025-12-06T21:08:12+00:00

[ 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 Tested-by: Sairaj Kodilkar Signed-off-by: Ashish Kalra Link: https://lore.kernel.org/r/576445eb4f168b467b0fc789079b650ca7c5b037.1756157913.git.ashish.kalra@amd.com Signed-off-by: Joerg Roedel Signed-off-by: Sasha Levin

iommu/amd: Avoid stack buffer overflow from kernel cmdline

2025-08-28T14:22:59+00:00

[ 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 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 Reviewed-by: Ankit Soni Link: https://lore.kernel.org/r/20250804154023.work.970-kees@kernel.org Signed-off-by: Joerg Roedel Signed-off-by: Sasha Levin

iommu/amd: Ensure GA log notifier callbacks finish running before module unload

2025-06-27T10:04:19+00:00

[ 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 Link: https://lore.kernel.org/r/20250315031048.2374109-1-seanjc@google.com Signed-off-by: Joerg Roedel Signed-off-by: Sasha Levin

iommu/amd: Fix potential buffer overflow in parse_ivrs_acpihid

2025-06-04T12:36:51+00:00

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 Link: https://lore.kernel.org/r/20250325092259.392844-1-Pavel.Paklov@cyberprotect.ru Signed-off-by: Joerg Roedel Signed-off-by: Greg Kroah-Hartman

iommu/amd: Return an error if vCPU affinity is set for non-vCPU IRTE

2025-05-02T05:41:15+00:00

[ 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 Message-ID: <20250404193923.1413163-6-seanjc@google.com> Signed-off-by: Paolo Bonzini Signed-off-by: Sasha Levin

iommu/amd: Fix sysfs leak in iommu init

2024-07-05T07:12:27+00:00

[ Upstream commit a295ec52c8624883885396fde7b4df1a179627c3 ] During the iommu initialization, iommu_init_pci() adds sysfs nodes. However, these nodes aren't remove in free_iommu_resources() subsequently. Fixes: 39ab9555c241 ("iommu: Add sysfs bindings for struct iommu_device") Signed-off-by: Kun(llfl) Reviewed-by: Suravee Suthikulpanit Link: https://lore.kernel.org/r/c8e0d11c6ab1ee48299c288009cf9c5dae07b42d.1715215003.git.llfl@linux.alibaba.com Signed-off-by: Joerg Roedel Signed-off-by: Sasha Levin

iommu/amd: Introduce pci segment structure

2024-07-05T07:12:27+00:00

[ Upstream commit 404ec4e4c169fb64da6b2a38b471c13ac0897c76 ] Newer AMD systems can support multiple PCI segments, where each segment contains one or more IOMMU instances. However, an IOMMU instance can only support a single PCI segment. Current code assumes that system contains only one pci segment (segment 0) and creates global data structures such as device table, rlookup table, etc. Introducing per PCI segment data structure, which contains segment specific data structures. This will eventually replace the global data structures. Also update `amd_iommu->pci_seg` variable to point to PCI segment structure instead of PCI segment ID. Co-developed-by: Suravee Suthikulpanit Signed-off-by: Suravee Suthikulpanit Signed-off-by: Vasant Hegde Link: https://lore.kernel.org/r/20220706113825.25582-3-vasant.hegde@amd.com Signed-off-by: Joerg Roedel Stable-dep-of: a295ec52c862 ("iommu/amd: Fix sysfs leak in iommu init") Signed-off-by: Sasha Levin

iommu/amd: Mark interrupt as managed

2024-03-26T22:21:50+00:00

[ Upstream commit 0feda94c868d396fac3b3cb14089d2d989a07c72 ] On many systems that have an AMD IOMMU the following sequence of warnings is observed during bootup. ``` pci 0000:00:00.2 can't derive routing for PCI INT A pci 0000:00:00.2: PCI INT A: not connected ``` This series of events happens because of the IOMMU initialization sequence order and the lack of _PRT entries for the IOMMU. During initialization the IOMMU driver first enables the PCI device using pci_enable_device(). This will call acpi_pci_irq_enable() which will check if the interrupt is declared in a PCI routing table (_PRT) entry. According to the PCI spec [1] these routing entries are only required under PCI root bridges: The _PRT object is required under all PCI root bridges The IOMMU is directly connected to the root complex, so there is no parent bridge to look for a _PRT entry. The first warning is emitted since no entry could be found in the hierarchy. The second warning is then emitted because the interrupt hasn't yet been configured to any value. The pin was configured in pci_read_irq() but the byte in PCI_INTERRUPT_LINE return 0xff which means "Unknown". After that sequence of events pci_enable_msi() is called and this will allocate an interrupt. That is both of these warnings are totally harmless because the IOMMU uses MSI for interrupts. To avoid even trying to probe for a _PRT entry mark the IOMMU as IRQ managed. This avoids both warnings. Link: https://uefi.org/htmlspecs/ACPI_Spec_6_4_html/06_Device_Configuration/Device_Configuration.html?highlight=_prt#prt-pci-routing-table [1] Signed-off-by: Mario Limonciello Fixes: cffe0a2b5a34 ("x86, irq: Keep balance of IOAPIC pin reference count") Reviewed-by: Vasant Hegde Link: https://lore.kernel.org/r/20240122233400.1802-1-mario.limonciello@amd.com Signed-off-by: Joerg Roedel Signed-off-by: Sasha Levin

iommu/amd: Don't block updates to GATag if guest mode is on

2023-06-09T08:30:04+00:00

[ Upstream commit ed8a2f4ddef2eaaf864ab1efbbca9788187036ab ] On KVM GSI routing table updates, specially those where they have vIOMMUs with interrupt remapping enabled (to boot >255vcpus setups without relying on KVM_FEATURE_MSI_EXT_DEST_ID), a VMM may update the backing VF MSIs with a new VCPU affinity. On AMD with AVIC enabled, the new vcpu affinity info is updated via: avic_pi_update_irte() irq_set_vcpu_affinity() amd_ir_set_vcpu_affinity() amd_iommu_{de}activate_guest_mode() Where the IRTE[GATag] is updated with the new vcpu affinity. The GATag contains VM ID and VCPU ID, and is used by IOMMU hardware to signal KVM (via GALog) when interrupt cannot be delivered due to vCPU is in blocking state. The issue is that amd_iommu_activate_guest_mode() will essentially only change IRTE fields on transitions from non-guest-mode to guest-mode and otherwise returns *with no changes to IRTE* on already configured guest-mode interrupts. To the guest this means that the VF interrupts remain affined to the first vCPU they were first configured, and guest will be unable to issue VF interrupts and receive messages like this from spurious interrupts (e.g. from waking the wrong vCPU in GALog): [ 167.759472] __common_interrupt: 3.34 No irq handler for vector [ 230.680927] mlx5_core 0000:00:02.0: mlx5_cmd_eq_recover:247:(pid 3122): Recovered 1 EQEs on cmd_eq [ 230.681799] mlx5_core 0000:00:02.0: wait_func_handle_exec_timeout:1113:(pid 3122): cmd[0]: CREATE_CQ(0x400) recovered after timeout [ 230.683266] __common_interrupt: 3.34 No irq handler for vector Given the fact that amd_ir_set_vcpu_affinity() uses amd_iommu_activate_guest_mode() underneath it essentially means that VCPU affinity changes of IRTEs are nops. Fix it by dropping the check for guest-mode at amd_iommu_activate_guest_mode(). Same thing is applicable to amd_iommu_deactivate_guest_mode() although, even if the IRTE doesn't change underlying DestID on the host, the VFIO IRQ handler will still be able to poke at the right guest-vCPU. Fixes: b9c6ff94e43a ("iommu/amd: Re-factor guest virtual APIC (de-)activation code") Signed-off-by: Joao Martins Reviewed-by: Suravee Suthikulpanit Link: https://lore.kernel.org/r/20230419201154.83880-2-joao.m.martins@oracle.com Signed-off-by: Joerg Roedel Signed-off-by: Sasha Levin