Re: [PATCH v1 3/4] iommu/hyperv: Add para-virtualized IOMMU support for Hyper-V guest

[Yu Zhang]

On Wed, May 20, 2026 at 11:27:08AM -0700, Jacob Pan wrote:
> Hi Yu,
> 
> On Wed, 20 May 2026 23:25:43 +0800
> Yu Zhang <zhangyu1@xxxxxxxxxxxxxxxxxxx> wrote:
> 
> > > > +static const struct iommu_domain_ops
> > > > hv_iommu_identity_domain_ops = {
> > > > +	.attach_dev	= hv_iommu_attach_dev,
> > > > +};
> > > > +
> > > > +static const struct iommu_domain_ops
> > > > hv_iommu_blocking_domain_ops = {
> > > > +	.attach_dev	= hv_iommu_attach_dev,
> > > > +};  
> > > 
> > > Usually I would expect these to have their own attach
> > > functions. blocking in particular must have an attach op that cannot
> > > fail. It is used to recover the device back to a known translation
> > > in case of cascading other errors.
> > >   
> > 
> > For blocking domain, the hypercall handler of such attach essentially
> > disable the translation and IOPF for the device.
> I think this should disable all faults, including unrecoverable fault
> reporting. right?

Yes, it should (e.g., my understanding is it shall set the FPD in scalable
mode context entry). Will double confirm with hypervisor team and make
sure it behaves so.

B.R.
Yu