Commit 9ce88066 authored by Jacob Pan's avatar Jacob Pan Committed by Zheng Zengkai
Browse files

iommu: Introduce attach/detach_pasid_table API 

maillist inclusion
category: feature
bugzilla: 51855
CVE: NA

Reference: https://jpbrucker.net/git/linux/commit/?h=sva/2021-03-01&id=ff9d3ac0df919b780a81ccfa54b4dc2eb69175a8



---------------------------------------------

In virtualization use case, when a guest is assigned
a PCI host device, protected by a virtual IOMMU on the guest,
the physical IOMMU must be programmed to be consistent with
the guest mappings. If the physical IOMMU supports two
translation stages it makes sense to program guest mappings
onto the first stage/level (ARM/Intel terminology) while the host
owns the stage/level 2.

In that case, it is mandated to trap on guest configuration
settings and pass those to the physical iommu driver.

This patch adds a new API to the iommu subsystem that allows
to set/unset the pasid table information.

A generic iommu_pasid_table_config struct is introduced in
a new iommu.h uapi header. This is going to be used by the VFIO
user API.

Reviewed-by: default avatarJean-Philippe Brucker <jean-philippe.brucker@arm.com>
Signed-off-by: default avatarJean-Philippe Brucker <jean-philippe.brucker@arm.com>
Signed-off-by: default avatarLiu, Yi L <yi.l.liu@linux.intel.com>
Signed-off-by: default avatarAshok Raj <ashok.raj@intel.com>
Signed-off-by: default avatarJacob Pan <jacob.jun.pan@linux.intel.com>
Signed-off-by: default avatarEric Auger <eric.auger@redhat.com>
Signed-off-by: default avatarLijun Fang <fanglijun3@huawei.com>
Reviewed-by: default avatarWeilong Chen <chenweilong@huawei.com>
Signed-off-by: default avatarZheng Zengkai <zhengzengkai@huawei.com>
parent 0c271f90

drivers/iommu/iommu.c

+19 −0
Original line number Diff line number Diff line
@@ -2173,6 +2173,25 @@ int iommu_uapi_sva_unbind_gpasid(struct iommu_domain *domain, struct device *dev 
}

EXPORT_SYMBOL_GPL(iommu_uapi_sva_unbind_gpasid);



int iommu_attach_pasid_table(struct iommu_domain *domain,

			     struct iommu_pasid_table_config *cfg)

{

	if (unlikely(!domain->ops->attach_pasid_table))

		return -ENODEV;



	return domain->ops->attach_pasid_table(domain, cfg);

}

EXPORT_SYMBOL_GPL(iommu_attach_pasid_table);



void iommu_detach_pasid_table(struct iommu_domain *domain)

{

	if (unlikely(!domain->ops->detach_pasid_table))

		return;



	domain->ops->detach_pasid_table(domain);

}

EXPORT_SYMBOL_GPL(iommu_detach_pasid_table);



static void __iommu_detach_device(struct iommu_domain *domain,

				  struct device *dev)

{

include/linux/iommu.h

+19 −0
Original line number Diff line number Diff line
@@ -241,6 +241,8 @@ struct iommu_iotlb_gather { 
 *		- IOMMU_DOMAIN_IDENTITY: must use an identity domain

 *		- IOMMU_DOMAIN_DMA: must use a dma domain

 *		- 0: use the default setting

 * @attach_pasid_table: attach a pasid table

 * @detach_pasid_table: detach the pasid table

 * @pgsize_bitmap: bitmap of all possible supported page sizes

 * @owner: Driver module providing these ops

 */
@@ -312,6 +314,9 @@ struct iommu_ops { 
			struct device *dev, struct iommu_gpasid_bind_data *data);



	int (*sva_unbind_gpasid)(struct device *dev, u32 pasid);

	int (*attach_pasid_table)(struct iommu_domain *domain,

				  struct iommu_pasid_table_config *cfg);

	void (*detach_pasid_table)(struct iommu_domain *domain);



	int (*def_domain_type)(struct device *dev);
@@ -451,6 +456,9 @@ extern int iommu_uapi_sva_unbind_gpasid(struct iommu_domain *domain, 
					struct device *dev, void __user *udata);

extern int iommu_sva_unbind_gpasid(struct iommu_domain *domain,

				   struct device *dev, ioasid_t pasid);

extern int iommu_attach_pasid_table(struct iommu_domain *domain,

				    struct iommu_pasid_table_config *cfg);

extern void iommu_detach_pasid_table(struct iommu_domain *domain);

extern struct iommu_domain *iommu_get_domain_for_dev(struct device *dev);

extern struct iommu_domain *iommu_get_dma_domain(struct device *dev);

extern int iommu_map(struct iommu_domain *domain, unsigned long iova,
@@ -1084,6 +1092,17 @@ static inline struct iommu_fwspec *dev_iommu_fwspec_get(struct device *dev) 
{

	return NULL;

}



static inline

int iommu_attach_pasid_table(struct iommu_domain *domain,

			     struct iommu_pasid_table_config *cfg)

{

	return -ENODEV;

}



static inline

void iommu_detach_pasid_table(struct iommu_domain *domain) {}



#endif /* CONFIG_IOMMU_API */



/**

include/uapi/linux/iommu.h

+51 −0
Original line number Diff line number Diff line
@@ -338,4 +338,55 @@ struct iommu_gpasid_bind_data { 
	} vendor;

};



/**

 * struct iommu_pasid_smmuv3 - ARM SMMUv3 Stream Table Entry stage 1 related

 *     information

 * @version: API version of this structure

 * @s1fmt: STE s1fmt (format of the CD table: single CD, linear table

 *         or 2-level table)

 * @s1dss: STE s1dss (specifies the behavior when @pasid_bits != 0

 *         and no PASID is passed along with the incoming transaction)

 * @padding: reserved for future use (should be zero)

 *

 * The PASID table is referred to as the Context Descriptor (CD) table on ARM

 * SMMUv3. Please refer to the ARM SMMU 3.x spec (ARM IHI 0070A) for full

 * details.

 */

struct iommu_pasid_smmuv3 {

#define PASID_TABLE_SMMUV3_CFG_VERSION_1 1

	__u32	version;

	__u8	s1fmt;

	__u8	s1dss;

	__u8	padding[2];

};



/**

 * struct iommu_pasid_table_config - PASID table data used to bind guest PASID

 *     table to the host IOMMU

 * @version: API version to prepare for future extensions

 * @format: format of the PASID table

 * @base_ptr: guest physical address of the PASID table

 * @pasid_bits: number of PASID bits used in the PASID table

 * @config: indicates whether the guest translation stage must

 *          be translated, bypassed or aborted.

 * @padding: reserved for future use (should be zero)

 * @smmuv3: table information when @format is %IOMMU_PASID_FORMAT_SMMUV3

 */

struct iommu_pasid_table_config {

#define PASID_TABLE_CFG_VERSION_1 1

	__u32	version;

#define IOMMU_PASID_FORMAT_SMMUV3	1

	__u32	format;

	__u64	base_ptr;

	__u8	pasid_bits;

#define IOMMU_PASID_CONFIG_TRANSLATE	1

#define IOMMU_PASID_CONFIG_BYPASS	2

#define IOMMU_PASID_CONFIG_ABORT	3

	__u8	config;

	__u8    padding[6];

	union {

		struct iommu_pasid_smmuv3 smmuv3;

	};

};



#endif /* _UAPI_IOMMU_H */