Commit 5dfaeb00 authored by Jean-Philippe Brucker's avatar Jean-Philippe Brucker Committed by Zheng Zengkai
Browse files

iommu: Add group variant for SVA bind/unbind 

maillist inclusion
category: feature
bugzilla: 51855
CVE: NA

Reference: https://jpbrucker.net/git/linux/commit/?h=sva/2021-03-01&id=7984f27d63b2f56dcdc106be9484061b3a13df0b



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

VFIO works directly with IOMMU groups rather than devices. Even if groups
ar still required to only contain one device in order to use SVA, add a
set of helpers for VFIO.

Signed-off-by: default avatarJean-Philippe Brucker <jean-philippe@linaro.org>
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 a3bc5676

drivers/iommu/iommu.c

+51 −21
Original line number Diff line number Diff line
@@ -3067,6 +3067,55 @@ int iommu_aux_get_pasid(struct iommu_domain *domain, struct device *dev) 
}

EXPORT_SYMBOL_GPL(iommu_aux_get_pasid);



struct iommu_sva_bind_group_data {

	struct mm_struct *mm;

	struct iommu_sva *handle;

	void *drvdata;

};



static int iommu_group_do_bind_dev(struct device *dev, void *data)

{

	struct iommu_sva_bind_group_data *bind = data;

	const struct iommu_ops *ops = dev->bus->iommu_ops;



	if (!ops || !ops->sva_bind)

		return -ENODEV;



	bind->handle = ops->sva_bind(dev, bind->mm, bind->drvdata);

	return PTR_ERR_OR_ZERO(bind->handle);

}



struct iommu_sva *

iommu_sva_bind_group(struct iommu_group *group, struct mm_struct *mm,

		     void *drvdata)

{

	int ret = -EINVAL;

	struct iommu_sva_bind_group_data data = {

		.mm = mm,

		.drvdata = drvdata,

	};



	/* Ensure device count and domain don't change while we're binding */

	mutex_lock(&group->mutex);



	/*

	 * To keep things simple, SVA currently doesn't support IOMMU groups

	 * with more than one device. Existing SVA-capable systems are not

	 * affected by the problems that required IOMMU groups (lack of ACS

	 * isolation, device ID aliasing and other hardware issues).

	 */

	if (iommu_group_device_count(group) != 1)

		goto out_unlock;



	ret = __iommu_group_for_each_dev(group, &data,

					 iommu_group_do_bind_dev);

out_unlock:

	mutex_unlock(&group->mutex);



	return ret ? ERR_PTR(ret) : data.handle;

}

EXPORT_SYMBOL_GPL(iommu_sva_bind_group);



/**

 * iommu_sva_bind_device() - Bind a process address space to a device

 * @dev: the device
@@ -3085,33 +3134,14 @@ EXPORT_SYMBOL_GPL(iommu_aux_get_pasid); 
struct iommu_sva *

iommu_sva_bind_device(struct device *dev, struct mm_struct *mm, void *drvdata)

{

	struct iommu_sva *handle;

	struct iommu_group *group;

	struct iommu_sva *handle = ERR_PTR(-EINVAL);

	const struct iommu_ops *ops = dev->bus->iommu_ops;



	if (!ops || !ops->sva_bind)

		return ERR_PTR(-ENODEV);



	group = iommu_group_get(dev);

	if (!group)

		return ERR_PTR(-ENODEV);



	/* Ensure device count and domain don't change while we're binding */

	mutex_lock(&group->mutex);



	/*

	 * To keep things simple, SVA currently doesn't support IOMMU groups

	 * with more than one device. Existing SVA-capable systems are not

	 * affected by the problems that required IOMMU groups (lack of ACS

	 * isolation, device ID aliasing and other hardware issues).

	 */

	if (iommu_group_device_count(group) != 1)

		goto out_unlock;



	handle = ops->sva_bind(dev, mm, drvdata);



out_unlock:

	mutex_unlock(&group->mutex);

	handle = iommu_sva_bind_group(group, mm, drvdata);

	iommu_group_put(group);



	return handle;

include/linux/iommu.h

+10 −0
Original line number Diff line number Diff line
@@ -666,6 +666,9 @@ int iommu_aux_get_pasid(struct iommu_domain *domain, struct device *dev); 
struct iommu_sva *iommu_sva_bind_device(struct device *dev,

					struct mm_struct *mm,

					void *drvdata);

extern struct iommu_sva *

iommu_sva_bind_group(struct iommu_group *group, struct mm_struct *mm,

		     void *drvdata);

void iommu_sva_unbind_device(struct iommu_sva *handle);

u32 iommu_sva_get_pasid(struct iommu_sva *handle);
@@ -1107,6 +1110,13 @@ int iommu_attach_pasid_table(struct iommu_domain *domain, 
static inline

void iommu_detach_pasid_table(struct iommu_domain *domain) {}



static inline struct iommu_sva *

iommu_sva_bind_group(struct iommu_group *group, struct mm_struct *mm,

		     void *drvdata)

{

	return -ENODEV;

}



#endif /* CONFIG_IOMMU_API */



/**