Re: [RFC PATCH 26/39] KVM: guest_memfd: Track faultability within a struct kvm_gmem_private

Jason Gunthorpe
2024-10-16T22:52:02Z

On Wed, Oct 16, 2024 at 04:16:17PM -0400, Peter Xu wrote:
>
> Is there chance that when !CoCo will be supported, then external modules
> (e.g. VFIO) can reuse the old user mappings, just like before gmemfd?
>
> To support CoCo, I understand gmem+offset is required all over the places.
> However in a non-CoCo context, I wonder whether the other modules are
> required to stick with gmem+offset, or they can reuse the old VA ways,
> because how it works can fundamentally be the same as before, except that
> the folios now will be managed by gmemfd.

My intention with iommufd was to see fd + offest as the "new" way
to refer to all guest memory and discourage people from using VMA
handles.

Jason