On Thu, 30 Jul 2026 at 11:27, Michael S. Tsirkin <[email protected]> wrote: > > On Thu, Jul 30, 2026 at 10:24:32AM +0100, Peter Maydell wrote: > > The idea is rather just to ignore the unaligned-access-to-not-RAM > > case as "only a theoretical issue" and default it to memmove(). > > If anybody reports an actual problem we can think about it then :-)
> Well given the only reported case of virtio DMA into vfio memory we have is > GH100 and that one is mapped MT_NORMAL, I'm fine with that. > I feel extending vfio to report the mapping type to userspace might > not be a bad idea down the road, though. "Directly accessible" > is a very rough approximation to the rich variety of mappings > available across architectures. Yes, this sounds like a good longer term idea. If userspace doesn't have a way to know what the mapping behind something it's mmap()ed is then it can't know what operations it can and can't safely do. -- PMM
