Re: [RFC 04/20] iommu: Add iommu_device_get_info interface

Lu Baolu
2021-09-29T09:29:30Z

On 2021/9/29 17:25, Lu Baolu wrote:
> Hi David,
>
> On 2021/9/29 10:52, David Gibson wrote:
>> On Sun, Sep 19, 2021 at 02:38:32PM +0800, Liu Yi L wrote:
>>> From: Lu Baolu<baolu.lu@linux.intel.com>
>>>
>>> This provides an interface for upper layers to get the per-device iommu
>>> attributes.
>>>
>>>      int iommu_device_get_info(struct device *dev,
>>>                                enum iommu_devattr attr, void *data);
>> That fact that this interface doesn't let you know how to size the
>> data buffer, other than by just knowing the right size for each attr
>> concerns me.
>>
>
> We plan to address this by following the comments here.
>
> https://lore.kernel.org/linux-iommu/20210921161930.GP327412@nvidia.com/

And Christoph gave another option as well.

https://lore.kernel.org/linux-iommu/20210922050746.GA12921@lst.de/

Best regards,
baolu