Enable nested virtualization

[felipecrs]

I don't know which is the hypervisor used to spin the VMs, but enabling nested virtualization would be a great enhancement. For example, this way we could build Vagrant boxes in GitHub Actions.

[felipecrs]

This feature is enabled by default in Travis CI. So I wonder why not here?

[dalehamel]

It looks like this is likely because azure only supports nested virtualization on dv3 or above https://azure.microsoft.com/en-ca/blog/nested-virtualization-in-azure/ but azure runs on ds2 instances: https://help.github.com/en/actions/automating-your-workflow-with-github-actions/virtual-environments-for-github-hosted-runners#cloud-hosts-for-github-hosted-runners

This seems to be older than dv3 from the catalogue: https://docs.microsoft.com/en-us/azure/virtual-machines/windows/sizes-general#dsv2-series vs https://docs.microsoft.com/en-us/azure/virtual-machines/windows/sizes-general#dv3-series-1

I haven't checked the exact CPU features, but i wonder if Hyper-V powering azure needs to work with a specific CPU family / featureset?

Has anyone tried just running KVM on azure? What happens? Is there even support for it in the stock azure / ubuntu kernel for bionic?

[dalehamel]

My use-case is I'd like to run an android emulator on Github Actions btw, like with https://github.com/google/android-emulator-container-scripts

[dalehamel]

When I run:

$egrep -c '(vmx|svm)' /proc/cpuinfo
0

This indicates there isn't CPU support, at least not passed through to the guest.

I installed kvm packages and was able to modprobe kvm, but there is no /dev/kvm, which is what I would expect.

Unless Azure adds support for this, or github actions switches / offers other machine classes, I don't think nested virtualization can be done.

[felipecrs]

Travis supports not only nested virtualization but also xvfb, that I guess you also need to run your Android tests.

https://github.com/felipecassiors/ubuntu1804-4dev/blob/master/.travis.yml

The support for nested virtualization is out-of-the-box there, where I use to build a Vagrant box using VirtualBox.

[AkihiroSuda]

https://github.com/actions/virtual-environments/blob/master/images/macos/macos-10.15-Readme.md

Intel x86 Emulator Accelerator (HAXM installer) | 7.5.1

macOS instances seem to support nested virtualization?
(I couldn't install VirtualBox though: #429)

[hannes]

+1, I would also really like to see this. I wonder what went wrong, if I manually spin up an equivalent Azure VM, it has vmx set and VirtualBox works fine with hardware acceleration.

[felipecrs]

Seems like it is possible indeed: https://docs.microsoft.com/en-us/azure/virtual-machines/windows/nested-virtualization

[dalehamel]

Yes azure supports it but not the instance type GitHub actions runs on

[hannes]

Works fine on Travis ^^