On Thu, Aug 21, 2025 at 11:30:43AM +0200, David Hildenbrand wrote: > > I will add this xen/apply_to_page_range() thing to my TODOs, which atm > > would invovle changing these drivers to use vmf_insert_pfn_prot() instead. > > > > Busy today (want to reply to Christian) but > > a) Re: performance, we would want something like > vmf_insert_pfns_prot(), similar to vm_insert_pages(), to bulk-insert > multiple PFNs. > > b) Re: PAT, we'll have to figure out why PAT information is wrong here > (was there no previous PAT reservation from the driver?), but IF we > really have to override, we'd want a way to tell > vmf_insert_pfn_prot() to force the selected caching mode. >
Ack, ok good that we have a feasible way forward. FYI, spoke to Peter off-list and he mentioned he had a more general series to get rid of this kind of [ab]use of apply_to_page_range() (see [0]), I gather he hasn't the time to resurrect but perhaps one of us can at some point? Perhaps we need a shorter term fix to _this_ issue (which involves not using this interface), and then follow it up with an adaptation of the below? Cheers, Lorenzo [0]:https://lore.kernel.org/all/20210412080012.357146...@infradead.org/ > -- > Cheers > > David / dhildenb
