Re: [Qemu-devel] [PATCH v4 2/3] memory: introduce IOMMUOps.notify_flag_changed

[Peter Xu]

On Wed, Sep 14, 2016 at 08:37:34PM +1000, David Gibson wrote:

[...]

> > This should not be related to the interface at all?
> > 
> > I was based on the assumption that "Power cannot support either one of
> > MAP/UNMAP, but only if both exist".
> 
> Huh? I have no idea what you mean by that.
> 
> Power can support notifying both map and unmap events just fine - but
> in order to provide *any* notifications, it has to disable KVM
> acceleration of the guest-side IOMMU (otherwise qemu won't know about
> any changes to the IOMMU state).
> 
> So the change you you suggested before to != IOMMU_NOTIFIER_NONE is
> exactly correct, anything else is not.

Sorry I was wrong. Yes user can register with only one (MAP or UNMAP)
notifier type for any platform.

Thanks.

-- peterx