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

[Tian, Kevin]

> From: Baolu Lu <baolu.lu@xxxxxxxxxxxxxxx>
> Sent: Wednesday, February 21, 2024 3:21 PM
> 
> 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?
> 

yes.