Commit 7d8b06ec authored by Suravee Suthikulpanit's avatar Suravee Suthikulpanit Committed by Joerg Roedel
Browse files

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: default avatarNicolin Chen <nicolinc@nvidia.com>
Reviewed-by: default avatarVasant Hegde <vasant.hegde@amd.com>
Reviewed-by: default avatarJason Gunthorpe <jgg@nvidia.com>
Signed-off-by: default avatarSuravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: default avatarJoerg Roedel <joerg.roedel@amd.com>
parent 2e666595

drivers/iommu/amd/Kconfig

+10 −0
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@@ -30,6 +30,16 @@ config AMD_IOMMU 
	  your BIOS for an option to enable it or if you have an IVRS ACPI

	  table.



config AMD_IOMMU_IOMMUFD

	bool "Enable IOMMUFD features for AMD IOMMU (EXPERIMENTAL)"

	depends on IOMMUFD

	depends on AMD_IOMMU

	help

	  Support for IOMMUFD features intended to support virtual machines

	  with accelerated virtual IOMMUs.



	  Say Y here if you are doing development and testing on this feature.



config AMD_IOMMU_DEBUGFS

	bool "Enable AMD IOMMU internals in DebugFS"

	depends on AMD_IOMMU && IOMMU_DEBUGFS

drivers/iommu/amd/Makefile

+1 −0
Original line number Diff line number Diff line 
# SPDX-License-Identifier: GPL-2.0-only

obj-y += iommu.o init.o quirks.o ppr.o pasid.o

obj-$(CONFIG_AMD_IOMMU_IOMMUFD) += iommufd.o

obj-$(CONFIG_AMD_IOMMU_DEBUGFS) += debugfs.o

drivers/iommu/amd/iommu.c

+2 −0
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@@ -43,6 +43,7 @@ 
#include <linux/generic_pt/iommu.h>



#include "amd_iommu.h"

#include "iommufd.h"

#include "../irq_remapping.h"

#include "../iommu-pages.h"
@@ -3083,6 +3084,7 @@ static bool amd_iommu_enforce_cache_coherency(struct iommu_domain *domain) 


const struct iommu_ops amd_iommu_ops = {

	.capable = amd_iommu_capable,

	.hw_info = amd_iommufd_hw_info,

	.blocked_domain = &blocked_domain,

	.release_domain = &blocked_domain,

	.identity_domain = &identity_domain.domain,

drivers/iommu/amd/iommufd.c

0 → 100644
+31 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0-only

/*

 * Copyright (C) 2025 Advanced Micro Devices, Inc.

 */



#include <linux/iommu.h>



#include "iommufd.h"

#include "amd_iommu.h"

#include "amd_iommu_types.h"



void *amd_iommufd_hw_info(struct device *dev, u32 *length, u32 *type)

{

	struct iommu_hw_info_amd *hwinfo;



	if (*type != IOMMU_HW_INFO_TYPE_DEFAULT &&

	    *type != IOMMU_HW_INFO_TYPE_AMD)

		return ERR_PTR(-EOPNOTSUPP);



	hwinfo = kzalloc(sizeof(*hwinfo), GFP_KERNEL);

	if (!hwinfo)

		return ERR_PTR(-ENOMEM);



	*length = sizeof(*hwinfo);

	*type = IOMMU_HW_INFO_TYPE_AMD;



	hwinfo->efr = amd_iommu_efr;

	hwinfo->efr2 = amd_iommu_efr2;



	return hwinfo;

}

drivers/iommu/amd/iommufd.h

0 → 100644
+15 −0
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/* SPDX-License-Identifier: GPL-2.0-only */

/*

 * Copyright (C) 2025 Advanced Micro Devices, Inc.

 */



#ifndef AMD_IOMMUFD_H

#define AMD_IOMMUFD_H



#if IS_ENABLED(CONFIG_AMD_IOMMU_IOMMUFD)

void *amd_iommufd_hw_info(struct device *dev, u32 *length, u32 *type);

#else

#define amd_iommufd_hw_info NULL

#endif /* CONFIG_AMD_IOMMU_IOMMUFD */



#endif /* AMD_IOMMUFD_H */