On Tue, Jan 25, 2022 at 10:40:01AM +0100, Eugenio Perez Martin wrote: > So I think that the first step to remove complexity from the old one > is to remove iova_begin and iova_end. > > As Jason points out, removing iova_end is easier. It has the drawback > of having to traverse all the list beyond iova_end, but a well formed > iova tree should contain none. If the guest can manipulate it, it's > only hurting itself adding nodes to it. > > It's possible to extract the check for hole_right (or this in Jason's > proposal) as a special case too. > > But removing the iova_begin parameter is more complicated. We cannot > know if it's a valid hole without knowing iova_begin, and we cannot > resume traversing. Could we assume iova_begin will always be 0? I > think not, the vdpa device can return anything through syscall. Frankly I don't know what's the syscall you're talking about, but after a 2nd thought and after I went back and re-read your previous version more carefully (the one without the list) I think it seems working to me in general. I should have tried harder when reviewing the first time! I mean this one: https://lore.kernel.org/qemu-devel/20211029183525.1776416-24-eperezma@xxxxxxxxxx/ Though this time I have some comments on the details. Personally I like that one (probably with some amendment upon the old version) more than the current list-based approach. But I'd like to know your thoughts too (including Jason). I'll further comment in that thread soon. Thanks, -- Peter Xu _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
