What I'm missing here is what software currently supports this format. Can I use it with QEMU? KVM? VirtualBox? VMware? If so, how? If not yet, when? If never, what's the actual use case?

This looks like OVA, firmware can be bundled inside along with additional disks, networking config, machine type and so on.

So essentially a virtual appliance package

I think people these days know better than to adopt Microslop standards

It would be nice to see a design document where the alternatives were considered and why this was invented to fill a gap. Otherwise, this just looks like reinventing the 20+ year old libvirt XML VM format.

There's an XKCD for this. https://xkcd.com/927/

Jesus Christ, Microsoft just can't quit doing this shit, can they?

cat CODEOWNERS

> * @microsoft/igvm-maintainers

... How is this "Independent"?

Looks like it means ‘Independent’ of the hypervisor used, I don’t think it’s a reference to it being an independent project. The QEMU post on this is a better read, I couldn’t tell from the GitHub what this was supposed to be. https://www.qemu.org/docs/master/system/igvm.html