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: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
This commit is contained in:
Lu Baolu 2020-12-09 09:44:44 +08:00 committed by Alex Williamson
parent bccce80bbd
commit bdfae1c9a9
3 changed files with 46 additions and 0 deletions

View file

@ -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
*/

View file

@ -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)

View file

@ -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,