On Thu, Aug 8, 2024 at 5:15 AM Wang, Wei W <wei.w.wang@xxxxxxxxx> wrote: > > On Thursday, August 8, 2024 1:22 AM, James Houghton wrote: > > 1. For guest_memfd, stage 2 mapping installation will never go through GUP / > > virtual addresses to do the GFN --> PFN translation, including when it supports > > non-private memory. > > 2. Something like KVM Userfault is indeed necessary to handle post-copy for > > guest_memfd VMs, especially when guest_memfd supports non-private > > memory. > > 3. We should not hook into the overall GFN --> HVA translation, we should > > only be hooking the GFN --> PFN translation steps to figure out how to create > > stage 2 mappings. That is, KVM's own accesses to guest memory should just go > > through mm/userfaultfd. > > Sorry.. still a bit confused about this one: will gmem finally support GUP and VMA? > For 1. above, seems no, but for 3. here, KVM's own accesses to gmem will go > through userfaultfd via GUP? > Also, how would vhost's access to gmem get faulted to userspace? Hi Wei,
