[PATCH v3 1/5] iommu: Return -EMEDIUMTYPE for incompatible domain and device/group

[Jason Gunthorpe]

On Fri, Jun 24, 2022 at 06:35:49PM +0800, Yong Wu wrote:

> > > It's not used in VFIO context. "return 0" just satisfy the iommu
> > > framework to go ahead. and yes, here we only allow the shared
> > > "mapping-domain" (All the devices share a domain created
> > > internally).

What part of the iommu framework is trying to attach a domain and
wants to see success when the domain was not actually attached ?

> > What prevent this driver from being used in VFIO context?
> 
> Nothing prevent this. Just I didn't test.

This is why it is wrong to return success here.

Jason