On Tue, Feb 21, 2017 at 17:33:54 CET, Daniel P. Berrange wrote: > On Tue, Feb 21, 2017 at 05:21:24PM +0100, Arno Wagner wrote: > > On Tue, Feb 21, 2017 at 14:58:07 CET, Daniel P. Berrange wrote: > > > On Tue, Feb 21, 2017 at 02:42:51PM +0100, michaelof@xxxxxxxxxxxxxx wrote: > > [...] > > > If the attacker has access to the physical host while your VM is running, > > > then (with current hardware) there is essentially nothing you can do to > > > prevent a skilled person getting your master key out of VM memory. AMD > > > recently announced a memory encryption feature that might make it possible > > > to protect guest keys from a host attacker, but its still very early days > > > in its developement & integration into virtualization technology, so a very > > > long way off being available in any public hosting provider. > > > > I think this is more about proteching VMs from each other than > > from the Hypervisor, think memory deduplication, copy-on-write > > and caches that leak information from one VM to another. > > Protecting the VM from the host is very much in scope of what AMD > is aiming to achieve with its SEV technology & KVM. The impl it > isn't there yet, but it is one of the intended targets. Well, _marketing_ may have put it in scope, but I very much doubt they can do it (because it is basically infeasible without taking control of the CPU away from its owner) and I expect AMD _engineering_ knows that. Regards, Arno -- Arno Wagner, Dr. sc. techn., Dipl. Inform., Email: arno@xxxxxxxxxxx GnuPG: ID: CB5D9718 FP: 12D6 C03B 1B30 33BB 13CF B774 E35C 5FA1 CB5D 9718 ---- A good decision is based on knowledge and not on numbers. -- Plato If it's in the news, don't worry about it. The very definition of "news" is "something that hardly ever happens." -- Bruce Schneier _______________________________________________ dm-crypt mailing list dm-crypt@xxxxxxxx http://www.saout.de/mailman/listinfo/dm-crypt
