Re: [PATCH v1 08/12] iommufd/viommu: Replace ops->viommu_alloc with ops->viommu_init

From: Baolu Lu
Date: Tue Jun 10 2025 - 01:56:18 EST


On 6/10/25 01:13, Nicolin Chen wrote:
To ease the for-driver iommufd APIs, get_viommu_size and viommu_init ops
are introduced. Now, those existing vIOMMU supported drivers implemented
these two ops too.

Relace the ops->viommu_alloc call with the two new ones.

Note that this will fail a !viommu->ops case from now on, since a vIOMMU
is expected to support alloc_domain_nested at least.

Does this mean that the viommu implementation in the iommu driver is
required to implement alloc_domain_nested? I suppose viommu should soon
be extended to support TEE/IO.


Suggested-by: Jason Gunthorpe<jgg@xxxxxxxxxx>
Signed-off-by: Nicolin Chen<nicolinc@xxxxxxxxxx>
---
drivers/iommu/iommufd/viommu.c | 30 +++++++++++++++++++++++++++---
1 file changed, 27 insertions(+), 3 deletions(-)


<...>

@@ -68,6 +82,16 @@ int iommufd_viommu_alloc_ioctl(struct iommufd_ucmd *ucmd)
*/
viommu->iommu_dev = __iommu_get_iommu_dev(idev->dev);
+ 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 = -EINVAL;
+ goto out_abort;
+ }
+
cmd->out_viommu_id = viommu->obj.id;
rc = iommufd_ucmd_respond(ucmd, sizeof(*cmd));
if (rc)

Thanks,
baolu