Commit bdfae1c9 authored by Lu Baolu's avatar Lu Baolu Committed by Alex Williamson
Browse files

vfio/type1: Add vfio_group_iommu_domain() 



Add the API for getting the domain from a vfio group. This could be used
by the physical device drivers which rely on the vfio/mdev framework for
mediated device user level access. The typical use case like below:

	unsigned int pasid;
	struct vfio_group *vfio_group;
	struct iommu_domain *iommu_domain;
	struct device *dev = mdev_dev(mdev);
	struct device *iommu_device = mdev_get_iommu_device(dev);

	if (!iommu_device ||
	    !iommu_dev_feature_enabled(iommu_device, IOMMU_DEV_FEAT_AUX))
		return -EINVAL;

	vfio_group = vfio_group_get_external_user_from_dev(dev);
	if (IS_ERR_OR_NULL(vfio_group))
		return -EFAULT;

	iommu_domain = vfio_group_iommu_domain(vfio_group);
	if (IS_ERR_OR_NULL(iommu_domain)) {
		vfio_group_put_external_user(vfio_group);
		return -EFAULT;
	}

	pasid = iommu_aux_get_pasid(iommu_domain, iommu_device);
	if (pasid < 0) {
		vfio_group_put_external_user(vfio_group);
		return -EFAULT;
	}

	/* Program device context with pasid value. */
	...

Signed-off-by: default avatarLu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: default avatarAlex Williamson <alex.williamson@redhat.com>
parent bccce80b

drivers/vfio/vfio.c

+18 −0
Original line number Diff line number Diff line
@@ -2331,6 +2331,24 @@ int vfio_unregister_notifier(struct device *dev, enum vfio_notify_type type, 
}

EXPORT_SYMBOL(vfio_unregister_notifier);



struct iommu_domain *vfio_group_iommu_domain(struct vfio_group *group)

{

	struct vfio_container *container;

	struct vfio_iommu_driver *driver;



	if (!group)

		return ERR_PTR(-EINVAL);



	container = group->container;

	driver = container->iommu_driver;

	if (likely(driver && driver->ops->group_iommu_domain))

		return driver->ops->group_iommu_domain(container->iommu_data,

						       group->iommu_group);



	return ERR_PTR(-ENOTTY);

}

EXPORT_SYMBOL_GPL(vfio_group_iommu_domain);



/**

 * Module/class support

 */

drivers/vfio/vfio_iommu_type1.c

+24 −0
Original line number Diff line number Diff line
@@ -2980,6 +2980,29 @@ static int vfio_iommu_type1_dma_rw(void *iommu_data, dma_addr_t user_iova, 
	return ret;

}



static struct iommu_domain *

vfio_iommu_type1_group_iommu_domain(void *iommu_data,

				    struct iommu_group *iommu_group)

{

	struct iommu_domain *domain = ERR_PTR(-ENODEV);

	struct vfio_iommu *iommu = iommu_data;

	struct vfio_domain *d;



	if (!iommu || !iommu_group)

		return ERR_PTR(-EINVAL);



	mutex_lock(&iommu->lock);

	list_for_each_entry(d, &iommu->domain_list, next) {

		if (find_iommu_group(d, iommu_group)) {

			domain = d->domain;

			break;

		}

	}

	mutex_unlock(&iommu->lock);



	return domain;

}



static const struct vfio_iommu_driver_ops vfio_iommu_driver_ops_type1 = {

	.name			= "vfio-iommu-type1",

	.owner			= THIS_MODULE,
@@ -2993,6 +3016,7 @@ static const struct vfio_iommu_driver_ops vfio_iommu_driver_ops_type1 = { 
	.register_notifier	= vfio_iommu_type1_register_notifier,

	.unregister_notifier	= vfio_iommu_type1_unregister_notifier,

	.dma_rw			= vfio_iommu_type1_dma_rw,

	.group_iommu_domain	= vfio_iommu_type1_group_iommu_domain,

};



static int __init vfio_iommu_type1_init(void)

include/linux/vfio.h

+4 −0
Original line number Diff line number Diff line
@@ -90,6 +90,8 @@ struct vfio_iommu_driver_ops { 
					       struct notifier_block *nb);

	int		(*dma_rw)(void *iommu_data, dma_addr_t user_iova,

				  void *data, size_t count, bool write);

	struct iommu_domain *(*group_iommu_domain)(void *iommu_data,

						   struct iommu_group *group);

};



extern int vfio_register_iommu_driver(const struct vfio_iommu_driver_ops *ops);
@@ -126,6 +128,8 @@ extern int vfio_group_unpin_pages(struct vfio_group *group, 
extern int vfio_dma_rw(struct vfio_group *group, dma_addr_t user_iova,

		       void *data, size_t len, bool write);



extern struct iommu_domain *vfio_group_iommu_domain(struct vfio_group *group);



/* each type has independent events */

enum vfio_notify_type {

	VFIO_IOMMU_NOTIFY = 0,

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