On Wed, Oct 16, 2024 at 07:51:57PM -0300, Jason Gunthorpe wrote: > 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. Does it mean anonymous memory guests will not be supported at all for iommufd? Indeed it's very rare now, lose quite some flexibility (v.s. fd based), and I can't think of a lot besides some default configs or KSM users (which I would expect rare), but still I wonder there're other use cases that people would still need to stick with anon, hence fd isn't around. Thanks, -- Peter Xu
