On Thu, Oct 17, 2024 at 11:17:19AM GMT, David Hildenbrand wrote: > On 16.10.24 20:39, Shakeel Butt wrote: > > Ccing couple more folks who are doing similar work (ASI, guest_memfd) > > > > Folks, what is the generic way to check if a given mapping has folios > > unmapped from kernel address space? > > > Can't we just lookup the mapping and refuse these folios that really > shouldn't be looked at? > > See gup_fast_folio_allowed() where we refuse secretmem_mapping(). That is exactly what this patch is doing. See [1]. The reason I asked this question was because I see parallel efforts related to guest_memfd and ASI are going to unmap folios from direct map. (Yosry already explained ASI is a bit different). We want a more robust and future proof solution. [1] https://lore.kernel.org/all/20241014235631.1229438-1-andrii@xxxxxxxxxx/ > > > -- > Cheers, > > David / dhildenb >
