On 23.11.21 10:06, Paolo Bonzini wrote: > On 11/19/21 16:39, David Hildenbrand wrote: >>> If qmeu can put all the guest memory in a memfd and not map it, then >>> I'd also like to see that the IOMMU can use this interface too so we >>> can have VFIO working in this configuration. >> >> In QEMU we usually want to (and must) be able to access guest memory >> from user space, with the current design we wouldn't even be able to >> temporarily mmap it -- which makes sense for encrypted memory only. The >> corner case really is encrypted memory. So I don't think we'll see a >> broad use of this feature outside of encrypted VMs in QEMU. I might be >> wrong, most probably I am:) > > It's not _that_ crazy an idea, but it's going to be some work to teach > KVM that it has to kmap/kunmap around all memory accesses. I'm also concerned about userspace access. But you sound like you have a plan :) -- Thanks, David / dhildenb
