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

[Tian, Kevin]

> From: Nicolin Chen <nicolinc@xxxxxxxxxx>
> 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