WHvCapabilityCodeHypervisorPresent is FALSE! Make sure you have enabled the 'Windows Hypervisor Plat

[ahm_bj]

I am running Virtual Box 6.1 and trying to boot linux ubuntu 18.04 64bits on that but I am having this error :

Failed to open a session for the virtual machine ubuntu.

WHvCapabilityCodeHypervisorPresent is FALSE! Make sure you have enabled the 'Windows Hypervisor Platform' feature. (VERR_NEM_NOT_AVAILABLE).

VT-x is not available (VERR_VMX_NO_VMX).

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

I have tried many things like activating/DEactivating Hyper-V, virtualization is activated in BIOS.

Attached below is the vbox.log generated

But always same issue. Could you please help me on this ?

Kind regards,

[scottgus1]

Please zip and post a guest vbox.log, using the forum's Upload Attachment tab.

[ahm_bj]

Hello sir, the log is uploaded in the attachments

[fth0]

virtualization is activated in BIOS

It looks like VirtualBox disagrees here, since it cannot detect the VT-x bit in the CPUID (VERR_VMX_NO_VMX). Hyper-V seems to be disabled, which is good. The VBox.log file confirms the information from your initial post.

Can you install and execute the CPU-Z software on your Windows host (wrong forum BTW ), and post either a screenshot of the CPU page, or the txt file it can create? This would give us more information about your CPU, which would come in a later part of the VBox.log file.

[scottgus1]

00:00:59.577514 VirtualBox VM 6.1.4 r136177 win.amd64 (Feb 18 2020 17:19:29) release log
...
00:00:59.577533 OS Product: Windows 10

Definitely the wrong forum. The real PC is the 'host'. The virtual machine is the 'guest'. Differentiating whether to put a topic in the 'host' or the 'guest' subforum can be tricky sometimes. But if you can't get the guest started, and a Virtualbox error comes up, then the 'host' subforum is a good place. In this case, Windows Hosts.

This error might also arise (I think) if Hyper-V is enabled and taking VT-x. See I have a 64bit host, but can't install 64bit guests.This tutorial will cover both checking if the bit is enabled in the BIOS and turning off everything that might enable Hyper-V that the forum gurus know about. Read carefully, there's a lot to look into.

[fth0]

This error might also arise (I think) if Hyper-V is enabled and taking VT-x.

Just being curious: Have you seen any case with WHvCapabilityCodeHypervisorPresent being false when Hyper-V was active?

[scottgus1]

To be honest, I haven't noticed the true or false part. I could be and probably am wrong...

[fth0]

I could be [...] wrong

Maybe, maybe not. I'm not so sure either. Too bad, that the CPUID dump is missing from the VBox.log file when the abort takes place so early. That's why I'm trying to get a second opinion from CPU-Z.

[fth0]

@scottgus1:

To be honest, I haven't noticed the true or false part. I could be and probably am wrong...

After consulting the VirtualBox source code and some older posts from user socratis, you seem to be wrong in assuming to be wrong, because you're probably right.

00:00:59.872097 HM: HMR3Init: Attempting fall back to NEM: VT-x is not available
[...]
00:00:59.903329 VT-x is not available (VERR_VMX_NO_VMX)

1) The VMX bit in the CPUID is not set. This happens either when VT-x is not enabled in the (UEFI) BIOS, or when VirtualBox is running under another hypervisor (e.g. Hyper-V) that intercepts the CPUID command and hides the VMX bit in the response. Assuming the latter case as the only possibility to proceed, VirtualBox tries to use Hyper-V (NEM, Native Execution Mode).

00:00:59.901881 VMSetError: WHvCapabilityCodeHypervisorPresent is FALSE! Make sure you have enabled the 'Windows Hypervisor Platform' feature.

2) The Windows Hyper-V Capability HypervisorPresent is not available. This means that the API necessary to programmatically create a Hyper-V partition (VM) is not available, and since VirtualBox cannot proceed without this API, it asks for the Windows Hypervisor Platform to be installed (*). But before this check is made, ...

1.5) ... VirtualBox has already detected that it is running under another hypervisor (the HVP (HyperVisor Present) bit in the CPUID is set). This is not reflected by a log file message, because it is the expected situation after the decision to try Hyper-V.

*) Either the Windows Hypervisor Platform is not installed, or it doesn't exist at all in Windows 10 1803 used here.

---

@ahm_bj:
What does that all mean? We know that VirtualBox is running under another hypervisor (1.5). The hypervisor could be the expected one (Hyper-V) or another one (e.g. VMware ESXi), and it must be disabled for VirtualBox to proceed. For the methods if the hypervisor is Hyper-V, see the second-to-previous post by scottgus1: viewtopic.php?f=7&t=97134#p473652

[mpack]

Topic moved to "Windows Hosts".