Re: [PATCH v2 10/22] iommufd/viommmu: Add IOMMUFD_CMD_VCMDQ_ALLOC ioctl

[Baolu Lu <baolu.lu@xxxxxxxxxxxxxxx>]

On 4/26/25 13:58, Nicolin Chen wrote:
> diff --git a/drivers/iommu/iommufd/viommu.c b/drivers/iommu/iommufd/viommu.c
> index a65153458a26..02a111710ffe 100644
> --- a/drivers/iommu/iommufd/viommu.c
> +++ b/drivers/iommu/iommufd/viommu.c
> @@ -170,3 +170,97 @@ int iommufd_vdevice_alloc_ioctl(struct iommufd_ucmd *ucmd)
>   	iommufd_put_object(ucmd->ictx, &viommu->obj);
>   	return rc;
>   }
> +
> +void iommufd_vcmdq_destroy(struct iommufd_object *obj)
> +{
> +	struct iommufd_vcmdq *vcmdq =
> +		container_of(obj, struct iommufd_vcmdq, obj);
> +	struct iommufd_viommu *viommu = vcmdq->viommu;
> +
> +	if (viommu->ops->vcmdq_destroy)
> +		viommu->ops->vcmdq_destroy(vcmdq);
> +	iopt_unpin_pages(&viommu->hwpt->ioas->iopt, vcmdq->addr, vcmdq->length);
> +	refcount_dec(&viommu->obj.users);
> +}
> +
> +int iommufd_vcmdq_alloc_ioctl(struct iommufd_ucmd *ucmd)
> +{
> +	struct iommu_vcmdq_alloc *cmd = ucmd->cmd;
> +	struct iommufd_viommu *viommu;
> +	struct iommufd_vcmdq *vcmdq;
> +	struct page **pages;
> +	int max_npages, i;
> +	dma_addr_t end;
> +	int rc;
> +
> +	if (cmd->flags || cmd->type == IOMMU_VCMDQ_TYPE_DEFAULT)

I don't follow the check of 'cmd->type == IOMMU_VCMDQ_TYPE_DEFAULT'
here. My understanding is that it states that "other values of type are
not supported". If so, shouldn't it be,

	if (cmd->flags || cmd->type != IOMMU_VCMDQ_TYPE_DEFAULT)

?

> +		return -EOPNOTSUPP;
> +	if (!cmd->addr || !cmd->length)
> +		return -EINVAL;
> +	if (check_add_overflow(cmd->addr, cmd->length - 1, &end))
> +		return -EOVERFLOW;

Thanks,
baolu