Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
iommu/amd: Add support for hw_info for iommu capability query
AMD IOMMU Extended Feature (EFR) and Extended Feature 2 (EFR2) registers
specify features supported by each IOMMU hardware instance.
The IOMMU driver checks each feature-specific bits before enabling
each feature at run time.
For IOMMUFD, the hypervisor passes the raw value of amd_iommu_efr and
amd_iommu_efr2 to VMM via iommufd IOMMU_DEVICE_GET_HW_INFO ioctl.
Reviewed-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Vasant Hegde <vasant.hegde@amd.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>
authored by
Suravee Suthikulpanit
and committed by
Joerg Roedel
7d8b06ec
2e666595
+87
+10
drivers/iommu/amd/Kconfig
+10
drivers/iommu/amd/Kconfig
···
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your BIOS for an option to enable it or if you have an IVRS ACPI
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table.
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config AMD_IOMMU_IOMMUFD
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bool "Enable IOMMUFD features for AMD IOMMU (EXPERIMENTAL)"
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depends on IOMMUFD
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depends on AMD_IOMMU
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help
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Support for IOMMUFD features intended to support virtual machines
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with accelerated virtual IOMMUs.
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Say Y here if you are doing development and testing on this feature.
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config AMD_IOMMU_DEBUGFS
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bool "Enable AMD IOMMU internals in DebugFS"
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depends on AMD_IOMMU && IOMMU_DEBUGFS
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drivers/iommu/amd/Makefile
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drivers/iommu/amd/Makefile
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drivers/iommu/amd/iommu.c
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drivers/iommu/amd/iommu.c
···
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#include <linux/generic_pt/iommu.h>
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#include "amd_iommu.h"
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#include "iommufd.h"
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#include "../irq_remapping.h"
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#include "../iommu-pages.h"
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···
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const struct iommu_ops amd_iommu_ops = {
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.capable = amd_iommu_capable,
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.hw_info = amd_iommufd_hw_info,
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.blocked_domain = &blocked_domain,
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.release_domain = &blocked_domain,
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.identity_domain = &identity_domain.domain,
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drivers/iommu/amd/iommufd.c
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drivers/iommu/amd/iommufd.c
···
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// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Copyright (C) 2025 Advanced Micro Devices, Inc.
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*/
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#include <linux/iommu.h>
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#include "iommufd.h"
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#include "amd_iommu.h"
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#include "amd_iommu_types.h"
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void *amd_iommufd_hw_info(struct device *dev, u32 *length, u32 *type)
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{
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struct iommu_hw_info_amd *hwinfo;
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if (*type != IOMMU_HW_INFO_TYPE_DEFAULT &&
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*type != IOMMU_HW_INFO_TYPE_AMD)
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return ERR_PTR(-EOPNOTSUPP);
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hwinfo = kzalloc(sizeof(*hwinfo), GFP_KERNEL);
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if (!hwinfo)
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return ERR_PTR(-ENOMEM);
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*length = sizeof(*hwinfo);
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*type = IOMMU_HW_INFO_TYPE_AMD;
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hwinfo->efr = amd_iommu_efr;
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hwinfo->efr2 = amd_iommu_efr2;
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return hwinfo;
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}
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drivers/iommu/amd/iommufd.h
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drivers/iommu/amd/iommufd.h
···
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/* SPDX-License-Identifier: GPL-2.0-only */
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/*
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* Copyright (C) 2025 Advanced Micro Devices, Inc.
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*/
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#ifndef AMD_IOMMUFD_H
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#define AMD_IOMMUFD_H
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#if IS_ENABLED(CONFIG_AMD_IOMMU_IOMMUFD)
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void *amd_iommufd_hw_info(struct device *dev, u32 *length, u32 *type);
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#else
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#define amd_iommufd_hw_info NULL
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#endif /* CONFIG_AMD_IOMMU_IOMMUFD */
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#endif /* AMD_IOMMUFD_H */
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include/uapi/linux/iommufd.h
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include/uapi/linux/iommufd.h
···
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};
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/**
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* struct iommu_hw_info_amd - AMD IOMMU device info
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*
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* @efr : Value of AMD IOMMU Extended Feature Register (EFR)
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* @efr2: Value of AMD IOMMU Extended Feature 2 Register (EFR2)
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*
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* Please See description of these registers in the following sections of
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* the AMD I/O Virtualization Technology (IOMMU) Specification.
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* (https://docs.amd.com/v/u/en-US/48882_3.10_PUB)
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*
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* - MMIO Offset 0030h IOMMU Extended Feature Register
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* - MMIO Offset 01A0h IOMMU Extended Feature 2 Register
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*
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* Note: The EFR and EFR2 are raw values reported by hardware.
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* VMM is responsible to determine the appropriate flags to be exposed to
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* the VM since cetertain features are not currently supported by the kernel
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* for HW-vIOMMU.
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*
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* Current VMM-allowed list of feature flags are:
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* - EFR[GTSup, GASup, GioSup, PPRSup, EPHSup, GATS, GLX, PASmax]
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*/
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struct iommu_hw_info_amd {
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__aligned_u64 efr;
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__aligned_u64 efr2;
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};
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/**
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* enum iommu_hw_info_type - IOMMU Hardware Info Types
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* @IOMMU_HW_INFO_TYPE_NONE: Output by the drivers that do not report hardware
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* info
···
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* @IOMMU_HW_INFO_TYPE_ARM_SMMUV3: ARM SMMUv3 iommu info type
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* @IOMMU_HW_INFO_TYPE_TEGRA241_CMDQV: NVIDIA Tegra241 CMDQV (extension for ARM
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* SMMUv3) info type
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* @IOMMU_HW_INFO_TYPE_AMD: AMD IOMMU info type
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*/
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enum iommu_hw_info_type {
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IOMMU_HW_INFO_TYPE_NONE = 0,
···
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IOMMU_HW_INFO_TYPE_INTEL_VTD = 1,
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IOMMU_HW_INFO_TYPE_ARM_SMMUV3 = 2,
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IOMMU_HW_INFO_TYPE_TEGRA241_CMDQV = 3,
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IOMMU_HW_INFO_TYPE_AMD = 4,
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};
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/**