[Solved] VT-x is not available, no solutions have worked

[CowsayRoot]

Hello Everyone,

I recently received a new laptop and have been trying to get some VMs up and running on it. I've been through Google and the forums trying to find the solution, and have seen multiple suggestions, but nothing has worked for me. Each time I try to start a VM, I get the following error:

Code: Select all

Failed to open a session for the virtual machine Kali-Linux-2018.4-vbox-amd64.

 (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}

Now my searches have told me that this is most commonly due to either virtualization not being enabled in BIOS, or Hyper-V running and not allowing VirtualBox access to VMX.
I have checked my machine's BIOS and confirmed that virtualization is enabled.
I have also checked my CPU (Intel Core i7-8550U) and ensured that it supports VT-x.
I have tried many things with Hyper-V including the following:

• Removing Hyper-V through Enable/Disable Features and conducting complete power-cycle
• Running the following command in an admin powershell (per <link removed, haven't been a member long enough>):

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  bcdedit /set hypervisorlaunchtype off

• Running the following command in an admin powershell (per <link removed, haven't been a member long enough>):

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  dism.exe /Online /Disable-Feature:Microsoft-Hyper-V

Versioning and other specs follow:
VirtualBox Version: 6.0.0
(I removed 6.0.0 and tried 5.2.22 and got the same error)
Host: Windows 10 Pro x64 v 1803
Guest: Kali Linux x64 v 2018.4 (logs provided)
Guest: Kali Linux x86 v 2018.4
Host Memory: 16GB
Guest Memory 2GB

At this point I'm at a loss, if anyone can provide me any guidance, I would appreciate it! And if this has already been solved somewhere else, and I missed it, I apologize for the redundant post.

[socratis]

You don't have a hardening problem, the availability of VT-x is not related to hardening. Something is using your VT-x. And it's not just the things that you mentioned. There's Device Guard for example...

After making 110% sure that Hyper-V is disabled in the Windows Features, you might want to make sure that Fast Boot is disabled and do a cold boot (i.e. shut down the host for a minute or two). You also must make sure that nothing else is using Hyper-V, things like antivirus, debuggers, emulators, etc. Check out the article "I have a 64bit host, but can't install 64bit guests" to get some ideas...

Also, Microsoft article on Credential Guard: Manage Windows Defender Credential Guard.

[CowsayRoot]

Yeah I didn't think it was a hardening problem, the forum guides just said to include it so I did. I've already been through those links that you sent, but I'll try what you recommended and report back with the results. Appreciate the response!

[CowsayRoot]

Well, I turned off fast boot, made sure that credential guard was disabled, then uninstalled the following: Sophos Home, Malwarebytes, Comodo Firewall, and did a complete power cycle. At this point, I am still getting the same error, and have very little left installed on my computer

[socratis]

and have very little left installed on my computer

It's either one of the installed remaining software, or a Win feature that you may have missed.

The problem is that there's no mechanism (yet) to tell which application/service is using VT-x, you have to try it by trial and error. That's also the reason that we cant offer you more than generic advice. You got to find what's "wrong" with your setup...

[CowsayRoot]

Understood, thanks for the help

[SurgeonX1]

I have exactly the same problem on a windows 8.1 machine.
But only after updating virtualbox.
Before everything works fine !
No change on the PC !
Can sb explaine what is vt -x ?? And what is ver vmx no vmx ???

Why does this happen only after update of virtualbox ??

Most faults i experienced were after simple update !

[CowsayRoot]

For those who have this problem, and none of the solutions are working, I ended up going into the BIOS, enabling virtualization (even though it was already disabled), saving and exiting. On my Lenovo x1, this led to two prompts asking me if I wanted to disable credentialguard and deviceguard, which I of course said to disable for each. Upon logging in and reinstalling virtualbox, everything worked like it should.

[socratis]

Great, thanks for the feedback. And thank you for marking the topic as [Solved]...

[sasos90]

I have Virtualization enabled, but still doesn't work. Any other ideas? Windows 10 with Hyper-V enabled (I need it for Docker).

[BillG]

No. If Hyper-V is enabled, VT-x is locked to the Windows hypervisor.

In version 6 of VirtualBox there is an option to run a vm (slowly) even if Hyper-V is enabled, but it is not operational yet.

[sasos90]

And when is this expected to be working correctly, if even?

[socratis]

When Microsoft stops being selfish! Complain to them!

The trick with VT-x is that it has to be shared, since it's "only one" available slot for its use. For example, VMware and VirtualBox (and until recently, KVM) do not use VT-x at the same time, but rather take turns. To put it simply, every program that uses VT-x should do this:

• VT-x lock
• Execute privileged VT-x code
• VT-x unlock

This way other processes can use VT-x in turns.

On the other hand, Hyper-V permanently takes over VT-x and doesn't let anyone else use it. If a program uses VT-x from the moment it is loaded, and doesn't let go till the moment it dies, you have a problem. So, please complain to Microsoft about that.

[swakop_toe]

There is ANOTHER option to disable in the Windows Features:
"Virtual Machine Platform"

[andyp73]

There is ANOTHER option to disable in the Windows Features: "Virtual Machine Platform"

It has been on the list of known culprits for a while which has appeared on many threads related to this subject in the list that looks like:

• Application Guard
• Credential Guard
• Device Guard
• <any> * Guard
• Containers
• Hyper-V
• Virtual Machine Platform
• Windows Hypervisor Platform
• Windows Sandbox

-Andy.