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Although this is very exciting. Surely performance is not the benefit here? It won’t perform better than android app built not on top of the virtualisation tdchnology?
Although this is very exciting. Surely performance is not the benefit here? It won’t perform better than android app built not on top of the virtualisation tdchnology?
If AVF allows running native code, it might actually be cheaper than the current arrangement.
So what is something running in this virtual machine allowed to do? Talk to the Internet? Talk to the screen? Talk only to whatever started it? How much of this is closed source?
Earlier quoted context omitted.
I agree that being able to isolate things that have different security domains is a useful tool. That said, I am not really seeing how pKVM provides useful primitives for much other than DRM, which has historically been the primary usecase for trusted execution that isolated VMs seem to provide.
Consider that, I want to be able to use a regular android OS, but I don't completely trust it, either its purposely malicious or just accidently going to leak info. So isolation is good in this case, its much easier to audit the mechanism of isolation rather than the whole OS. The problem with DRM and "trusted computing" part is that it's under someone else's control, some central authority etc. From my reading of th…
Earlier quoted context omitted.
I agree that being able to isolate things that have different security domains is a useful tool. That said, I am not really seeing how pKVM provides useful primitives for much other than DRM, which has historically been the primary usecase for trusted execution that isolated VMs seem to provide.
I'd love for my banking app to be completely isolated from the rest of my phone OS, in case I get malware. I'm sure journalists at risk of targeting by NSO and its ilk would appreciate isolation or their messaging apps
Earlier quoted context omitted.
I agree that being able to isolate things that have different security domains is a useful tool. That said, I am not really seeing how pKVM provides useful primitives for much other than DRM, which has historically been the primary usecase for trusted execution that isolated VMs seem to provide.
As I said in my other response, I make heavy use of trusted (confidential) VMs for machine learning in cloud environments. There are also vendors that are doing smart contract execution in trusted computing devices so you can get the benefits of trusted execution without the overhead of everyone executing the same code.
Earlier quoted context omitted.
No, KVM is also a type 1 hypervisor but it doesn't attempt (with the exception of pKVM and of hardware protection features like SEV, neither of which is routinely used by cloud workloads) to protect the guest from a malicious host.
Where in my comment did I refer explicitly to KVM feature set, or that it is used by cloud vendors?
So it's true that "most cloud workloads run on type 1 hypervisors" (KVM is one) but not that most cloud vendors/workloads run on microkernel-like hypervisors, with the exception of Azure.
Earlier quoted context omitted.
The threat model you have in your head seems to imply that you don't trust your OS to not peek into what Whisper is doing? There are very few workloads that need or can operate under that model.
So I'm most familiar with using this in cases like machine learning on private data in cloud environments where you want to make it impossible for the cloud operator to see the data you are using. I think there are usecases like this outside the mobile _phone_ that are interesting. For example on-device learning for edge devices where the device is not under your control.
Earlier quoted context omitted.
No, KVM is also a type 1 hypervisor but it doesn't attempt (with the exception of pKVM and of hardware protection features like SEV, neither of which is routinely used by cloud workloads) to protect the guest from a malicious host.
KVM is a type 2 hypervisor as the "Dom 0" kernel has full HW access. Other guests are obviously isolated as configured and are like special processes to userspace. It gets a bit blurry on AArch64 without and with VHE (Virtual Host Extensions) as without VHE ( https://lwn.net/Articles/650524/ )
* VMM is treated as synonymous with hypervisor
* "Extended host" is defined as "A pseudo-machine [99], also called an extended machine [53] or a user machine [75], is a composite machine produced through a combination of hardware and software, in which the machine's apparent architecture has been changed slightly to make the machine more convenient to use. Typically these architectural changes have taken the form of removing I/O channels and devices, and adding system calls to perform I/O and and other operations"
In other words, type 1 ("bare machine hypervisor") runs in supervisor mode and type 2 runs in user mode. QEMU running in dynamic binary translation mode is a type 2 VMM.
KVM runs on a bare machine, but it delegates some services to a less privileged component such as QEMU or crosvm or Firecracker. This is not a type 2 hypervisor, it is a type 1 hypervisor that follows security principles such as privilege separation.