RE: [PATCH v1 09/16] iommufd/viommmu: Add IOMMUFD_CMD_VCMDQ_ALLOC ioctl

Tian, Kevin
2025-04-21T08:05:44Z

> From: Nicolin Chen <nicolinc@nvidia.com>
> Sent: Friday, April 11, 2025 2:38 PM
>
> +
> +/**
> + * enum iommu_vcmdq_type - Virtual Queue Type

"Virtual Command Queue Type"

> + * @IOMMU_VCMDQ_TYPE_DEFAULT: Reserved for future use
> + */
> +enum iommu_vcmdq_data_type {
> + IOMMU_VCMDQ_TYPE_DEFAULT = 0,
> +};
> +
> +/**
> + * struct iommu_vcmdq_alloc - ioctl(IOMMU_VCMDQ_ALLOC)
> + * @size: sizeof(struct iommu_vcmdq_alloc)
> + * @flags: Must be 0
> + * @viommu_id: viommu ID to associate the virtual queue with
> + * @type: One of enum iommu_vcmdq_type

s/ iommu_vcmdq_type/ iommu_vcmdq_data_type/

> +int iommufd_vcmdq_alloc_ioctl(struct iommufd_ucmd *ucmd)
> +{
> + struct iommu_vcmdq_alloc *cmd = ucmd->cmd;
> + const struct iommu_user_data user_data = {
> + .type = cmd->type,
> + .uptr = u64_to_user_ptr(cmd->data_uptr),
> + .len = cmd->data_len,
> + };
> + struct iommufd_vcmdq *vcmdq;
> + struct iommufd_viommu *viommu;
> + int rc;
> +
> + if (cmd->flags || cmd->type == IOMMU_VCMDQ_TYPE_DEFAULT)
> + return -EOPNOTSUPP;
> + if (!cmd->data_len)
> + return -EINVAL;
> +
> + viommu = iommufd_get_viommu(ucmd, cmd->viommu_id);
> + if (IS_ERR(viommu))
> + return PTR_ERR(viommu);
> +
> + if (!viommu->ops || !viommu->ops->vcmdq_alloc) {
> + rc = -EOPNOTSUPP;
> + goto out_put_viommu;
> + }
> +
> + vcmdq = viommu->ops->vcmdq_alloc(viommu,
> + user_data.len ? &user_data : NULL);

the length cannot be zero at this point due to earlier check.