Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Virtual Machine as a core Android Primitive

android-developers.googleblog.com

Post reply on HN
Print view View original

71–80 of 177 posts

Re: Virtual Machine as a core Android Primitive

#71

Post by bonzini »

pjmlp wrote: post #70
jbott wrote: post #62

Earlier quoted context omitted.

It looks like the host kernel is not in full control – there is a EL2-level hypervisor, pKVM [1] that is actually the highest-privilege domain. This is pretty similar to the Xen architecture [1] where the dom0 linux os in charge of managing the machine is running as a guest of the hypervisor. 1. https://source.android.com/docs/core/virtualization/architec... 2. https://wiki.xenproject.org/wiki/Xen_Project_Software_Ov…

Commonly known as type 1 hypervisor architecture, by opposition to type 2 hypervisor, which run as OS services. Ironically the revenge of microkernels, as most cloud workloads run on type 1 hypervisors.

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.

Re: Virtual Machine as a core Android Primitive

#73

Post by ungamedplayer »

bonzini wrote: post #42
fleventynine wrote: post #22

Earlier quoted context omitted.

> if I spin up a VM with networking disabled I feel pretty confident I can run anything safely, even malware is not going to escape. You are putting too much faith in your VM monitor to keep you safe. There's a lot of attack surface in (for example) QEMU peripherals, and there's plenty of examples of VM escape [1]. CrosVM is probably the only publicly available VMM I'd be willing to trust, and even then I'd be nervou…

While QEMU uses C, which is not great, it has on its side 15+ years of hardening by the KVM developers. The problem with QEMU is not so much insecurity, it's that it contains the kitchen sink. However, most of the exploits you'll find in QEMU are against configurations that are never used in real world virtualization scenarios where guests are untrusted. You can recognize them because hardware not commonly used with…

> You can recognize them because hardware not commonly used with untrusted guests does not get a CVE.

This is not true. Even non default configuration of any software or hardware that contains a security vulnerability can get a CVE. It has in the past and will again in the future.

Source: I have assigned over 2000 cves for the kernel.

Re: Virtual Machine as a core Android Primitive

#75

Post by jeffrallen »

transpute wrote: post #72
jeffrallen wrote: post #69

Another salvo in the war on general purpose computing.( https://lwn.net/Articles/473794/ )

If Android phones can run non-Android VMs of the user's choice, the phones will gain new purpose.

Ok cool.

But you and I both know that this feature was designed for the DMCA-lovin' Hollywood types and the control-freak enterprise IT BOFHs, not for your cool hack.

Let's use their tools of oppression against them! (fist emoji)

Re: Virtual Machine as a core Android Primitive

#78

Post by pjmlp »

bonzini wrote: post #71
pjmlp wrote: post #70

Earlier quoted context omitted.

Commonly known as type 1 hypervisor architecture, by opposition to type 2 hypervisor, which run as OS services. Ironically the revenge of microkernels, as most cloud workloads run on type 1 hypervisors.

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?

Re: Virtual Machine as a core Android Primitive

#80

Post by Vogtinator »

bonzini wrote: post #71
pjmlp wrote: post #70

Earlier quoted context omitted.

Commonly known as type 1 hypervisor architecture, by opposition to type 2 hypervisor, which run as OS services. Ironically the revenge of microkernels, as most cloud workloads run on type 1 hypervisors.

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/)

Post reply on HN