can't run virtualbox 6.1.4 with hyper-v

Question

I'm running VirtualBox 6.1.4 with Hyper-V but when I try to open up a VM I get the following error:

Failed to open a session for the virtual machine vagrant_default_1583698990398_29087.

VMMR0_DO_NEM_INIT_VM failed: VERR_NEM_MISSING_KERNEL_API (VERR_NEM_MISSING_KERNEL_API).

VT-x is not available (VERR_VMX_NO_VMX).

Result Code: E_FAIL (0x80004005)
Component: ConsoleWrap
Interface: IConsole {872da645-4a9b-1727-bee2-5585105b9eed}

According to https://www.virtualbox.org/wiki/Changelog-6.0 VirtualBox 6.0.0 introduced Hyper-V support. Quoting it:

Added support for using Hyper-V as the fallback execution core on Windows host, to avoid inability to run VMs at the price of reduced performance

So what gives? Is Hyper-V supported or not?

I'm running Microsoft Windows [Version 10.0.18363.657]. Here is what "Apps & Features" says I have installed: https://pastebin.com/dJrg7yD8. Here's what "Turn Windows features on or off" says: https://pastebin.com/6RT0xeN0

Solution 1

I have virtualbox 6.1.26 installed and it runs perfectly with Hyper-V enabled, which I require because I also run Docker.

I made the mistake by upgrading my virtualbox version (to 6.1.28) and next thing you know is I cannot run with Hyper-V enabled. Had to downgrade again to get it working.

The takeaway is perhaps, don't rush to update your virtualbox if it is already working.

--

I remember now why years ago I started using VMWare, because updating virtualbox usually breaks my VMs. This is sad given they advertise a new version always on startup.

Solution 2

The issue is due to the enablement of Core Isolation features within Windows that automatically get enabled with several versions of Windows feature pack updates, including Windows Update Pack 20H2 and others.

If you do not have the hardware to support Core Isolation, Virtualbox will function with the Hyper-V role enabled on any system with VT-x enabled as normal, which explains why many users do not encounter the issue you have. However, if your system supports even some of many hardware security features (like any Windows 11-capable systems with TPM 2.0 hardware security), you can encounter this problem because when the Core isolation feature is enabled, Windows will obfuscate the existence of the VT-x hardware virtualization support from the primary running windows environment (known as "dom0" in the old Xen parlance, which Hyper-V was originally based on).

The easiest method is to disable the necessary hardware security features is by using the Device Guard and Credential Guard hardware readiness tool available from Microsoft here: https://www.microsoft.com/en-us/download/details.aspx?id=53337

Then disabling with:

DG_Readiness_Tool_v3.5.ps1 -Disable -AutoReboot

You can find additional information on the feature here: https://support.microsoft.com/en-us/windows/device-protection-in-windows-security-afa11526-de57-b1c5-599f-3a4c6a61c5e2#hardwarescore

Note this will however disable these security features, which come with the expected risks that you will have to evaluate for yourself (but place your system in the identical state it was in prior to the enablement of these features).

Comments

[Ramhound]

Does this answer your question? Virtual box is not working on windows 10

[essjae]

There are bugs with it, there's at least one ticket with VirtualBox. It may work, but a lot of people have issues with it: virtualbox.org/ticket/18387

[neubert]

@Ramhound - I edited my post.

[Ramhound]

The startup and relevant information from the other VirtualBox log files will be required to help you.

[jrh]

I couldn't run it with Hyper-V either in the latest version of VirtualBox at the time of writing, the only thing that got it working was to completely disable Hyper-V, which means more than just turning Hyper-V off in Programs and Features because it appears that now HyperV is used as a security feature in Windows 10 (as of 1909).