Sorry for the late reply, I was on leave last week. On Tue, Apr 29, 2025 at 06:46:59AM -0700, Vishal Annapurve wrote: > On Mon, Apr 28, 2025 at 5:52 PM Yan Zhao <yan.y.zhao@xxxxxxxxx> wrote: > > So, we plan to remove folio_ref_add()/folio_put_refs() in future, only invoking > > folio_ref_add() in the event of a removal failure. > > In my opinion, the above scheme can be deployed with this series > itself. guest_memfd will not take away memory from TDX VMs without an I initially intended to add a separate patch at the end of this series to implement invoking folio_ref_add() only upon a removal failure. However, I decided against it since it's not a must before guest_memfd supports in-place conversion. We can include it in the next version If you think it's better. > invalidation. folio_ref_add() will not work for memory not backed by > page structs, but that problem can be solved in future possibly by With current TDX code, all memory must be backed by a page struct. Both tdh_mem_page_add() and tdh_mem_page_aug() require a "struct page *" rather than a pfn. > notifying guest_memfd of certain ranges being in use even after > invalidation completes. A curious question: To support memory not backed by page structs in future, is there any counterpart to the page struct to hold ref count and map count?
