RE: [PATCH v5 01/13] iommufd/viommu: Add IOMMUFD_OBJ_VDEVICE and IOMMU_VDEVICE_ALLOC ioctl

From: Nicolin Chen nicolinc@nvidia.com Sent: Saturday, October 26, 2024 7:51 AM

+/**

• • struct iommu_vdevice_alloc - ioctl(IOMMU_VDEVICE_ALLOC)
• • @size: sizeof(struct iommu_vdevice_alloc)
• • @viommu_id: vIOMMU ID to associate with the virtual device
• • @dev_id: The pyhsical device to allocate a virtual instance on the

vIOMMU

s/pyhsical/physical/, or just say 'iommufd device"

+int iommufd_vdevice_alloc_ioctl(struct iommufd_ucmd *ucmd) +{

• struct iommu_vdevice_alloc *cmd = ucmd->cmd;
• struct iommufd_vdevice *vdev, *curr;
• struct iommufd_viommu *viommu;
• struct iommufd_device *idev;
• u64 virt_id = cmd->virt_id;
• int rc = 0;
• if (virt_id > ULONG_MAX)

• return -EINVAL;
  

• viommu = iommufd_get_viommu(ucmd, cmd->viommu_id);
• if (IS_ERR(viommu))

• return PTR_ERR(viommu);
  

• idev = iommufd_get_device(ucmd, cmd->dev_id);
• if (IS_ERR(idev)) {

• rc = PTR_ERR(idev);
  

• goto out_put_viommu;
  

• }
• mutex_lock(&idev->igroup->lock);
• if (idev->vdev) {

• rc = -EEXIST;
  

• goto out_unlock_igroup;
  

• }
• vdev = iommufd_object_alloc(ucmd->ictx, vdev,

IOMMUFD_OBJ_VDEVICE);

• if (IS_ERR(vdev)) {

• rc = PTR_ERR(vdev);
  

• goto out_unlock_igroup;
  

• }

also need to check that the device and the viommu are associated to a same physical iommu.

• rc = iommufd_verify_unfinalized_object(ucmd->ictx, &vdev->obj);
• if (rc) {

• kfree(vdev);
  

• goto out_unlock_igroup;
  

• }
• vdev->idev = idev;
• vdev->id = virt_id;
• vdev->viommu = viommu;
• idev->vdev = vdev;
• refcount_inc(&idev->obj.users);
• refcount_inc(&viommu->obj.users);
• curr = xa_cmpxchg(&viommu->vdevs, virt_id, NULL, vdev,

GFP_KERNEL);

• if (curr) {

• rc = xa_err(curr) ?: -EBUSY;
  

• goto out_abort;
  

• }
• cmd->out_vdevice_id = vdev->obj.id;
• rc = iommufd_ucmd_respond(ucmd, sizeof(*cmd));
• if (rc)

• goto out_abort;
  

• iommufd_object_finalize(ucmd->ictx, &vdev->obj);
• goto out_unlock_igroup;

+out_abort:

• iommufd_object_abort_and_destroy(ucmd->ictx, &vdev->obj);

+out_unlock_igroup:

• mutex_unlock(&idev->igroup->lock);
• iommufd_put_object(ucmd->ictx, &idev->obj);

+out_put_viommu:

• iommufd_put_object(ucmd->ictx, &viommu->obj);
• return rc;

+}

2.43.0