Re: [PATCH v3 1/8] iommu: Add iopf domain attach/detach/replace interface

[Baolu Lu <baolu.lu@linux.intel.com>]

On 2024/2/21 14:49, Tian, Kevin wrote:
>>>> +struct iopf_attach_cookie {
>>>> +	struct iommu_domain *domain;
>>>> +	struct device *dev;
>>>> +	unsigned int pasid;
>>>> +	refcount_t users;
>>>> +
>>>> +	void *private;
>>>> +	void (*release)(struct iopf_attach_cookie *cookie);
>>>> +};
>>> this cookie has nothing specific to iopf.
>>>
>>> it may makes more sense to build a generic iommu_attach_device_cookie()
>>> helper so the same object can be reused in future other usages too.
>>>
>>> within iommu core it can check domain iopf handler and this generic cookie
>>> to update iopf specific data e.g. the pasid_cookie xarray.
>> This means attaching an iopf-capable domain follows two steps:
>>
>> 1) Attaching the domain to the device.
>> 2) Setting up the iopf data, necessary for handling iopf data.
>>
>> This creates a time window during which the iopf is enabled, but the
>> software cannot handle it. Or not?
>>
> why two steps? in attach you can setup the iopf data when recognizing
> that the domain is iopf capable...

Oh, maybe I misunderstood. So your proposal is to make the new interface
generic, not for iopf only?

Best regards,
baolu