On Tue, Jan 29, 2019 at 01:39:49PM -0700, Logan Gunthorpe wrote: > implement the mapping. And I don't think we should have 'special' vma's > for this (though we may need something to ensure we don't get mapping > requests mixed with different types of pages...). I think Jerome explained the point here is to have a 'special vma' rather than a 'special struct page' as, really, we don't need a struct page at all to make this work. If I recall your earlier attempts at adding struct page for BAR memory, it ran aground on issues related to O_DIRECT/sgls, etc, etc. This does seem to avoid that pitfall entirely as we can never accidently get into the SGL system with this kind of memory or VMA? Jason
