Commit 0d609a14 authored by Jason Gunthorpe's avatar Jason Gunthorpe Committed by Joerg Roedel
Browse files

iommu: Add domain_alloc_identity() 



virtio-iommu has a mode where the IDENTITY domain is actually a paging
domain with an identity mapping covering some of the system address
space manually created.

To support this add a new domain_alloc_identity() op that accepts
the struct device so that virtio can allocate and fully finalize a
paging domain to return.

Signed-off-by: default avatarJason Gunthorpe <jgg@nvidia.com>
Reviewed-by: default avatarKevin Tian <kevin.tian@intel.com>
Link: https://lore.kernel.org/r/2-v4-ff5fb6b03bd1+288-iommu_virtio_domains_jgg@nvidia.com


Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
parent 0d76a6ed

drivers/iommu/iommu.c

+12 −8
Original line number Diff line number Diff line
@@ -1631,15 +1631,19 @@ static struct iommu_domain *__iommu_alloc_identity_domain(struct device *dev) 
	if (ops->identity_domain)

		return ops->identity_domain;



	/* Older drivers create the identity domain via ops->domain_alloc() */

	if (!ops->domain_alloc)

		return ERR_PTR(-EOPNOTSUPP);



	domain = ops->domain_alloc(IOMMU_DOMAIN_IDENTITY);

	if (ops->domain_alloc_identity) {

		domain = ops->domain_alloc_identity(dev);

		if (IS_ERR(domain))

			return domain;

	} else if (ops->domain_alloc) {

		domain = ops->domain_alloc(IOMMU_DOMAIN_IDENTITY);

		if (!domain)

			return ERR_PTR(-ENOMEM);

		if (IS_ERR(domain))

			return domain;

	} else {

		return ERR_PTR(-EOPNOTSUPP);

	}



	iommu_domain_init(domain, IOMMU_DOMAIN_IDENTITY, ops);

	return domain;

include/linux/iommu.h

+4 −0
Original line number Diff line number Diff line
@@ -567,6 +567,9 @@ iommu_copy_struct_from_full_user_array(void *kdst, size_t kdst_entry_size, 
 * @domain_alloc: allocate and return an iommu domain if success. Otherwise

 *                NULL is returned. The domain is not fully initialized until

 *                the caller iommu_domain_alloc() returns.

 * @domain_alloc_identity: allocate an IDENTITY domain. Drivers should prefer to

 *                         use identity_domain instead. This should only be used

 *                         if dynamic logic is necessary.

 * @domain_alloc_paging_flags: Allocate an iommu domain corresponding to the

 *                     input parameters as defined in

 *                     include/uapi/linux/iommufd.h. The @user_data can be
@@ -625,6 +628,7 @@ struct iommu_ops { 


	/* Domain allocation and freeing by the iommu driver */

	struct iommu_domain *(*domain_alloc)(unsigned iommu_domain_type);

	struct iommu_domain *(*domain_alloc_identity)(struct device *dev);

	struct iommu_domain *(*domain_alloc_paging_flags)(

		struct device *dev, u32 flags,

		const struct iommu_user_data *user_data);