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

[Baolu Lu]

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