Commit 22195cbd authored by Jike Song's avatar Jike Song Committed by Alex Williamson
Browse files

vfio: vfio_register_notifier: classify iommu notifier 



Currently vfio_register_notifier assumes that there is only one
notifier chain, which is in vfio_iommu. However, the user might
also be interested in events other than vfio_iommu, for example,
vfio_group. Refactor vfio_{un}register_notifier implementation
to make it feasible.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Reviewed-by: default avatarKirti Wankhede <kwankhede@nvidia.com>
Signed-off-by: default avatarJike Song <jike.song@intel.com>
[aw: merge with commit 816ca69ea9c7 ("vfio: Fix handling of error returned by 'vfio_group_get_from_dev()'"), remove typedef]
Signed-off-by: default avatarAlex Williamson <alex.williamson@redhat.com>
parent d256459f

drivers/vfio/vfio.c

+59 −25
Original line number Diff line number Diff line
@@ -2008,59 +2008,44 @@ err_unpin_pages: 
}

EXPORT_SYMBOL(vfio_unpin_pages);



int vfio_register_notifier(struct device *dev, struct notifier_block *nb)

static int vfio_register_iommu_notifier(struct vfio_group *group,

					unsigned long *events,

					struct notifier_block *nb)

{

	struct vfio_container *container;

	struct vfio_group *group;

	struct vfio_iommu_driver *driver;

	int ret;



	if (!dev || !nb)

		return -EINVAL;



	group = vfio_group_get_from_dev(dev);

	if (!group)

		return -ENODEV;



	ret = vfio_group_add_container_user(group);

	if (ret)

		goto err_register_nb;

		return -EINVAL;



	container = group->container;

	down_read(&container->group_lock);



	driver = container->iommu_driver;

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

		ret = driver->ops->register_notifier(container->iommu_data, nb);

		ret = driver->ops->register_notifier(container->iommu_data,

						     events, nb);

	else

		ret = -ENOTTY;



	up_read(&container->group_lock);

	vfio_group_try_dissolve_container(group);



err_register_nb:

	vfio_group_put(group);

	return ret;

}

EXPORT_SYMBOL(vfio_register_notifier);



int vfio_unregister_notifier(struct device *dev, struct notifier_block *nb)

static int vfio_unregister_iommu_notifier(struct vfio_group *group,

					  struct notifier_block *nb)

{

	struct vfio_container *container;

	struct vfio_group *group;

	struct vfio_iommu_driver *driver;

	int ret;



	if (!dev || !nb)

		return -EINVAL;



	group = vfio_group_get_from_dev(dev);

	if (!group)

		return -ENODEV;



	ret = vfio_group_add_container_user(group);

	if (ret)

		goto err_unregister_nb;

		return -EINVAL;



	container = group->container;

	down_read(&container->group_lock);
@@ -2075,7 +2060,56 @@ int vfio_unregister_notifier(struct device *dev, struct notifier_block *nb) 
	up_read(&container->group_lock);

	vfio_group_try_dissolve_container(group);



err_unregister_nb:

	return ret;

}



int vfio_register_notifier(struct device *dev, enum vfio_notify_type type,

			   unsigned long *events, struct notifier_block *nb)

{

	struct vfio_group *group;

	int ret;



	if (!dev || !nb || !events || (*events == 0))

		return -EINVAL;



	group = vfio_group_get_from_dev(dev);

	if (!group)

		return -ENODEV;



	switch (type) {

	case VFIO_IOMMU_NOTIFY:

		ret = vfio_register_iommu_notifier(group, events, nb);

		break;

	default:

		ret = -EINVAL;

	}



	vfio_group_put(group);

	return ret;

}

EXPORT_SYMBOL(vfio_register_notifier);



int vfio_unregister_notifier(struct device *dev, enum vfio_notify_type type,

			     struct notifier_block *nb)

{

	struct vfio_group *group;

	int ret;



	if (!dev || !nb)

		return -EINVAL;



	group = vfio_group_get_from_dev(dev);

	if (!group)

		return -ENODEV;



	switch (type) {

	case VFIO_IOMMU_NOTIFY:

		ret = vfio_unregister_iommu_notifier(group, nb);

		break;

	default:

		ret = -EINVAL;

	}



	vfio_group_put(group);

	return ret;

}

drivers/vfio/vfio_iommu_type1.c

+8 −0
Original line number Diff line number Diff line
@@ -1584,10 +1584,18 @@ static long vfio_iommu_type1_ioctl(void *iommu_data, 
}



static int vfio_iommu_type1_register_notifier(void *iommu_data,

					      unsigned long *events,

					      struct notifier_block *nb)

{

	struct vfio_iommu *iommu = iommu_data;



	/* clear known events */

	*events &= ~VFIO_IOMMU_NOTIFY_DMA_UNMAP;



	/* refuse to register if still events remaining */

	if (*events)

		return -EINVAL;



	return blocking_notifier_chain_register(&iommu->notifier, nb);

}

include/linux/vfio.h

+11 −2
Original line number Diff line number Diff line
@@ -81,6 +81,7 @@ struct vfio_iommu_driver_ops { 
	int		(*unpin_pages)(void *iommu_data,

				       unsigned long *user_pfn, int npage);

	int		(*register_notifier)(void *iommu_data,

					     unsigned long *events,

					     struct notifier_block *nb);

	int		(*unregister_notifier)(void *iommu_data,

					       struct notifier_block *nb);
@@ -107,12 +108,20 @@ extern int vfio_pin_pages(struct device *dev, unsigned long *user_pfn, 
extern int vfio_unpin_pages(struct device *dev, unsigned long *user_pfn,

			    int npage);



#define VFIO_IOMMU_NOTIFY_DMA_UNMAP	(1)

/* each type has independent events */

enum vfio_notify_type {

	VFIO_IOMMU_NOTIFY = 0,

};



/* events for VFIO_IOMMU_NOTIFY */

#define VFIO_IOMMU_NOTIFY_DMA_UNMAP	BIT(0)



extern int vfio_register_notifier(struct device *dev,

				  enum vfio_notify_type type,

				  unsigned long *required_events,

				  struct notifier_block *nb);



extern int vfio_unregister_notifier(struct device *dev,

				    enum vfio_notify_type type,

				    struct notifier_block *nb);



/*

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