Commit 63141fa7 authored by Nicolin Chen's avatar Nicolin Chen Committed by Jason Gunthorpe
Browse files

iommufd/viommu: Support get_viommu_size and viommu_init ops 

To ease the for-driver iommufd APIs, get_viommu_size and viommu_init ops
are introduced to replace the viommu_init op.

Let the new viommu_init pathway coexist with the old viommu_alloc one.

Since the viommu_alloc op and its pathway will be soon deprecated, try to
minimize the code difference between them by adding a tentative jump tag.

Note that this fails a !viommu->ops case from now on with a WARN_ON_ONCE
since a vIOMMU is expected to support an alloc_domain_nested op for now,
or some sort of a viommu op in the foreseeable future. This WARN_ON_ONCE
can be lifted, if some day there is a use case wanting !viommu->ops.

Link: https://patch.msgid.link/r/35c5fa5926be45bda82f5fc87545cd3180ad4c9c.1749882255.git.nicolinc@nvidia.com


Suggested-by: default avatarJason Gunthorpe <jgg@nvidia.com>
Signed-off-by: default avatarNicolin Chen <nicolinc@nvidia.com>
Reviewed-by: default avatarJason Gunthorpe <jgg@nvidia.com>
Reviewed-by: default avatarKevin Tian <kevin.tian@intel.com>
Reviewed-by: default avatarLu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: default avatarJason Gunthorpe <jgg@nvidia.com>
parent 187f146d

drivers/iommu/iommufd/viommu.c

+39 −3
Original line number Diff line number Diff line
@@ -21,6 +21,7 @@ int iommufd_viommu_alloc_ioctl(struct iommufd_ucmd *ucmd) 
	struct iommufd_viommu *viommu;

	struct iommufd_device *idev;

	const struct iommu_ops *ops;

	size_t viommu_size;

	int rc;



	if (cmd->flags || cmd->type == IOMMU_VIOMMU_TYPE_DEFAULT)
@@ -31,11 +32,29 @@ int iommufd_viommu_alloc_ioctl(struct iommufd_ucmd *ucmd) 
		return PTR_ERR(idev);



	ops = dev_iommu_ops(idev->dev);

	if (!ops->viommu_alloc) {

	if (!ops->get_viommu_size || !ops->viommu_init) {

		if (ops->viommu_alloc)

			goto get_hwpt_paging;

		rc = -EOPNOTSUPP;

		goto out_put_idev;

	}



	viommu_size = ops->get_viommu_size(idev->dev, cmd->type);

	if (!viommu_size) {

		rc = -EOPNOTSUPP;

		goto out_put_idev;

	}



	/*

	 * It is a driver bug for providing a viommu_size smaller than the core

	 * vIOMMU structure size

	 */

	if (WARN_ON_ONCE(viommu_size < sizeof(*viommu))) {

		rc = -EOPNOTSUPP;

		goto out_put_idev;

	}



get_hwpt_paging:

	hwpt_paging = iommufd_get_hwpt_paging(ucmd, cmd->hwpt_id);

	if (IS_ERR(hwpt_paging)) {

		rc = PTR_ERR(hwpt_paging);
@@ -47,8 +66,13 @@ int iommufd_viommu_alloc_ioctl(struct iommufd_ucmd *ucmd) 
		goto out_put_hwpt;

	}



	viommu = ops->viommu_alloc(idev->dev, hwpt_paging->common.domain,

	if (ops->viommu_alloc)

		viommu = ops->viommu_alloc(idev->dev,

					   hwpt_paging->common.domain,

					   ucmd->ictx, cmd->type);

	else

		viommu = (struct iommufd_viommu *)_iommufd_object_alloc(

			ucmd->ictx, viommu_size, IOMMUFD_OBJ_VIOMMU);

	if (IS_ERR(viommu)) {

		rc = PTR_ERR(viommu);

		goto out_put_hwpt;
@@ -68,6 +92,18 @@ int iommufd_viommu_alloc_ioctl(struct iommufd_ucmd *ucmd) 
	 */

	viommu->iommu_dev = __iommu_get_iommu_dev(idev->dev);



	if (!ops->viommu_alloc) {

		rc = ops->viommu_init(viommu, hwpt_paging->common.domain);

		if (rc)

			goto out_abort;

	}



	/* It is a driver bug that viommu->ops isn't filled */

	if (WARN_ON_ONCE(!viommu->ops)) {

		rc = -EOPNOTSUPP;

		goto out_abort;

	}



	cmd->out_viommu_id = viommu->obj.id;

	rc = iommufd_ucmd_respond(ucmd, sizeof(*cmd));

	if (rc)