> From: Baolu Lu <baolu.lu@xxxxxxxxxxxxxxx> > Sent: Thursday, March 16, 2023 4:30 PM > > On 2023/3/16 16:16, Tian, Kevin wrote: > >> + * allocated in the IOMMU driver and the caller should free it > >> + * after use. Return the data buffer if success, or ERR_PTR on > >> + * failure. > >> * @domain_alloc: allocate iommu domain > >> * @probe_device: Add device to iommu driver handling > >> * @release_device: Remove device from iommu driver handling > >> @@ -246,11 +252,17 @@ struct iommu_iotlb_gather { > >> * @remove_dev_pasid: Remove any translation configurations of a > specific > >> * pasid, so that any DMA transactions with this pasid > >> * will be blocked by the hardware. > >> + * @driver_type: One of enum iommu_hw_info_type. This is used in the > >> hw_info > >> + * reporting path. For the drivers that supports it, a unique > >> + * type should be defined. For the driver that does not support > >> + * it, this field is the IOMMU_HW_INFO_TYPE_DEFAULT that is 0. > >> + * Hence, such drivers do not need to care this field. > > The meaning of "driver_type" is much broader than reporting hw_info. > > > > let's be accurate to call it as "hw_info_type". and while we have two > > separate fields for one feature where is the check enforced on whether > > both are provided? > > > > Is it simpler to return the type directly in @hw_info? > > If I remember correctly, the vendor iommu type and hardware info are > reported to user space separately. > there is only one IOMMU_DEVICE_GET_HW_INFO cmd. It's written as: data = ops->hw_info(idev->dev, &data_len); copy_to_user(u64_to_user_ptr(cmd->data_ptr), data, length); cmd->out_data_type = ops->driver_type;