Defender Application Guard requires CPU virtualization extensions?

Question

I'm looking at the Defender Secure Score setting "Turn on Microsoft Defender Application Guard managed mode". I found an MS article to understand the requirements.

Upon reading the article, it has a hardware requirement called CPU virtualization extensions which includes (image below):

1. Extended page tables, also called Second Level Address Translation (SLAT)
2. Virtual extensions

My questions are:

1. I tried systeminfo (cmd.exe) and I'm getting "A hypervisor has been detected. Features required for Hyper-V will not be displayed." Any other places I can find SLAT?
2. Are virtual extensions just referring to virtualization technology (i.e. vmware, hyper-v, virtualbox, etc.)? If so, is Hyper-v required to be enabled? I could see it clashing with other virtualization technology if so.

Answer 1

I tried systeminfo (cmd.exe) and I'm getting "A hypervisor has been detected. Features required for Hyper-V will not be displayed." Any other places I can find SLAT?

If it's an Intel CPU, look it up on Intel's ARK product information page – it'll be listed as "Intel® VT-x with Extended Page Tables (EPT)".

The reason WDAG requires SLAT is because Hyper-V requires SLAT, so if the system has Hyper-V working then you probably have the feature. (The message you're seeing is fairly typical for a system that's already running on top of Hyper-V.)

Are virtual extensions just referring to virtualization technology (i.e. vmware, hyper-v, virtualbox, etc.)? If so, is Hyper-v required to be enabled? I could see it clashing with other virtualization technology if so.

Yes, it's referring to the CPU feature that allows all those systems to work. WDAG requires the same CPU virtualization support – I believe it literally uses the same "Windows Hypervisor" as Hyper-V does, so it has the same hardware requirements. (It's not the full Hyper-V, just the "backend" that's shared between Hyper-V, WDAG, and WHP.)

You're right that multiple such virtualization apps can't use the VT-x feature at the same time. However, WDAG actually uses the same hypervisor as Hyper-V does, so the two won't conflict. These days VirtualBox is also able to use Hyper-V's hypervisor (the "Windows Virtualization Platform") instead of its own, so it should be compatible with WDAG, mostly.