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Sunday, 19 June 2016 16:07

My VirtualBox Notes

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These are my VirtualBox notes.

Official Sites

General

  • Release the cursor from the VM 
    Right Ctrl key
  • Release the cursor from the VM when in scaled mode 
    Right Ctrl + C
  • Extension Pack
    The main installer has option for USB 3.0, so I am not sure if this will prompt to add the extension pack or if it part of the main program.
  • Guest Additions
  • phpvirtualbox
  • Cannot change Boot order in settings
    • Legacy BIOS VMs:
      • Press F12 during VM startup to select a boot device for that session 
    • If the VM uses EFI:
      • Use the ESC key during startup or adjust disk/controller order for a workaround.
      • If you're already using EFI/UEFI, this is different. The EFI firmware has its own NVRAM boot entries.
      • VirtualBox doesn't provide a normal GUI option for rearranging those EFI entries.
      • You need to modify the EFI variables/NVRAM, typically from inside the VM using efibootmgr on Linux, or using the UEFI shell. For example from Linux: efibootmgr
      • Adjust Disk/Controller Order: VirtualBox prioritizes the disk attached to Port 0 of a SATA/IDE controller. Moving your bootable disk to Port 0 can enforce boot priority.
  • Storage Devices are missing in settings (Settings --> Storage --> Devices)
    • At the top-left, select expert mode and the hidden stuff will appear
    • Sometimes there is a blank line at the top, in basic mode, which is the parent controller (buggy)
    • Try removing everything by clicking the button until it is greyed out, save settings and start again.
    • Additionally, after wiping all storage devices, save and then make your changes.
  • Virtualbox keeps toggling Num Lock
    • You will notice this if you have an on-screen display for Num Lock.
    • This is quite normal as the Num Lock state is swapped to match which machine(or host) has focus.
    • Disable the on-screen notification.
  • Windows XP taking forever to load / Crashes with a CPU error (Windows 11 host)
    • Cause:
      • This is caused by Core Isolation being enabled.
      • Hyper-V running underneath VirtualBox is the single most common cause of exactly this error on XP guests on modern Windows hosts.
    • Solution:
      • Disable Core Isolation / Disable Hyper-V 
      • Settings --> Device security --> Core Isolation --> Memory integrity: Off
        • You will need to reboot.
      • This resolves this exact symptom for a lot of people, because Hyper-V's virtualization-based security conflicts with how VirtualBox exposes the CPU to an XP guest.
    • Links:
  • Installation
  • mtrr: your CPUs had inconsistent variable MTRR settings
    • This error might be caused by `Core Isolation` settings.
  • Make a disk with fixed size and do snapshots ?
    • I guess when the snapshots are removed, the VM will revert to a single disk again. While there are snapshots, effectively a parallel dynamic disk/file will be run along side it as an overlay. This will affect performance.
    • Don't run snapshots on a live production server.
  • Copy and Paste
  • Preallocate or Fixed disk (move to disk image managment)
  • Missing Device icons at the bottom of the window
  • Parallel Port
    • Can't give VirtualBox guest OS access to host physical LPT1 port | Super Users
    • How to enable parallel port? | Reddit
      • I was running WinXP in VirtualBox v4.0.x. It is dedicated for a legacy parallel/LPT port device that only has drivers for WinXP 32bit.
      • The host is Win7 x64.
      • It was working just fine for a long time. Recently, I updated VirtualBox to the latest v6.1.0 and now when I startup the WinXP vm, I get this error about no parallel port. And I can't find any settings to enable it.
    • Enabling and Configuring Parallel (LPTx) Ports - virtualbox.org
      • On several occasions the mods have been asked for instructions on how to enable and configure LPT (parallel port) passthrough in a guest.
      • LPT passthrough is a feature which has been requested for years, and was finally implemented with very little fanfare in VirtualBox v4.2.0 (*).
      • The release logs and documentation make only passing mention of it, which possibly reflects a low level of confidence the devs have in this new feature.
      • Basically, it's an (almost) undocumented feature, so if you can't get it to work... well just don't expect too much.
    • Passthrough questions - virtualbox.org
      • Should I be able to do the USB to LPT on the host machine and just pass through the LPT port?
      • Should I be able to pass through an AGP or PCI video card to the guest while keeping the onboard video for the host?
        Anything else I'm not thinking of?
  • VirtualBox multicore issue
  • Snapshots
  • Virtuabox vs VMWare vs Hyper-V
  • Should I enable PAE/NX ?
    • Yes, for all modern OSes. This should only need turning of for really old OSes.
    • This option does control 2 separate but related features.
    • DEP requires NX
    • What is PAE/NX in VirtualBox? | Quora
      • PAE (Physical Address Extension)
      • NX (No-Execute), also called XD (eXecute Disable) on Intel
      • Default choice: Enable PAE/NX for modern guests unless you have a specific compatibility reason not to. It improves security (NX) and enables expanded memory for 32-bit guests (PAE).
      • Enable it for modern OSes and for 32-bit guests that must access >4 GiB or require PAE.
      • In-depth answer.
    • When do I have to use PAE/NX? | Super User
      • Now, let's return to the fact that the checkbox is for PAE/NX. The same tricks used to make more memory locations accessible can also be used to add in an NX-bit. Again from the second paragraph of the PAE Wikipedia article:
      • In-depth answer.
    • Unlocking the Power of PAE NX in VirtualBox: A Comprehensive Guide - SmartTechSavvy - In this article, we will delve into the world of PAE NX in VirtualBox, exploring what it is, how it works, and its benefits and limitations.
    • Physical Address Extension - Wikipedia
    • NX bit - Wikipedia
    • How to Enable Processor-Based Security: DEP, NX/XD, Memory Integrity | iTechguides
      • How to enable processor-based security in Windows: check and configure DEP with NX/XD and BCDEdit, then enable Memory integrity for VBS/HVCI when hardware and drivers support it.
      • Hardware DEP uses NX on AMD processors or XD on Intel processors to prevent code from executing in memory pages marked for data.
      • Older applications and drivers can fail when DEP or Memory integrity blocks behavior that is unsafe, obsolete, unsigned, or incompatible.
    • Windows DEP Explained: How It Protects Memory and How to Manage It | WindowsForum
      • Data Execution Prevention (DEP) is one of those quietly powerful Windows defenses that rarely makes headlines — until it blocks something you’re trying to run.
      • Built to stop code from executing in memory regions reserved for data, DEP reduces the damage that buffer overflows and similar memory exploits can cause.
      • This feature uses both CPU hardware flags (NX/XD) and software fallbacks to enforce execution policies, and it’s enabled by default on modern Windows installations.
      • For most users DEP should stay turned on; for administrators and power users, understanding how DEP works, how to check its status, and how to safely troubleshoot exceptions is essential to balancing compatibility and security.

Tutorials

Misc

Startup and shutdown

Mount a RAW drive

Backing Up a Live Server

Performance

Host Machine

  • Get a newer PC with at least 16GB RAM and a modern prosesor with loads of cores
  • Put Your Virtual Machines on a Solid-State Drive system rather than traitional drives for your host
  • Ensure Intel VT-x or AMD-V Is Enabled in the BIOS (VirtualBox wont run without this now)
    • This stops windows intercepting opcodes passed to the CPU by the virtualization technologies
  • Exclude Virtual Machine Directories In Your Antivirus   
  • Change Power Plan to High Performance 
    Control Panel --> Power Options --> Change Plan Settings   
  • Disable Hyper-V & Windows hypervisor (wintips)
    1. Navigate to Control Panel > Programs and Features > Turn Windows features on or off : Disable the following
      • Containers  *                   (off by default)
      • Hyper-V      *                  (off by default)
      • Virtual Machine Platform        (off by default)
      • Windows Hypervisor Platform     (off by default)
      • Windows Sandbox                 (off by default)
      • * Note: The 'Containers' and the 'Hyper-V' features exists only in Windows 10 PRO.
           
    2. bcdedit /set hypervisorlaunchtype off
  • make sure windows updates are all applied as these usually cause a general slow down in your PC.
    • My system will not download or install them unless I click to do so.
  • Having the latest VirtualBox is probably a good thing.
  • Disable `Core Isolation` as this has known performance issues especially with older OSes.
  • Use nVME drives as they are quicker adn can handle modern disk formats better.
  • The Complete Guide to Speeding Up Your Virtual Machines | How-To-Geek - Virtual machines are demanding beasts, providing virtual hardware and running multiple operating systems on your computer at once.
  • Speed up a VirtualBox Virtual Machine and make it run faster | The Windows Club
    • The speed and performance of a Virtual Machine depend on the specifications of the host machine like RAM, processor, etc.
    • But sometimes, despite having a powerful computer, the Virtual Machine runs slow.
    • In this article, we will describe some methods that will help you make your Virtual Machine run faster.
  • Virus scanning recommendations for Enterprise computers that are running Windows or Windows Server (KB822158) | Microsoft Support
    • Describes recommendations that might help you protect a computer that is running Windows from viruses.
    • Delves into issues you might have with software and how to apply exclusions safely.
  • Antivirus Slowing Your PC Down? Maybe You Should Use Exclusions | How-To-Geek - Protecting your computer with an antivirus solution is par for the course when you’re dealing with a Windows PC, but unfortunately it slows you down at the same time. Here’s how to improve your performance, at least a little bit.
  • FIX: VirtualBox Running Very Slow in Windows 10/11. (Solved) - WinTips.org - Several methods to optimize VirtualBox's performance under Windows 10/11 (FIX: VirtualBox is running very slow on Windows 11/10)
  • [Fixed] VirtualBox VMs are too Slow on Windows 11 Host - Sysprobs - VirtualBox VMs are too slow on Windows 11/10 with a green turtle? Here is the working solution to bring back the speed & V symbol. TURTLE
  • Fix VirtualBox VM Running Slow on Windows 11 (Step by Step) | MCSA Guru
    • VirtualBox crawling on Windows 11? Hyper-V, Memory Integrity, and WSL2 steal VT-x. Learn what to disable, how to allocate resources, and enable nested paging.
    • If VT-x or Nested Paging is greyed out or refuses to enable, either virtualization is turned off in the host’s UEFI/BIOS, or the Windows hypervisor is still holding the extensions. Enable Intel VT-x / AMD-V (sometimes called SVM) in firmware, and re-check that the Hyper-V stack is fully off per the steps above.
  • Working with Virtual Machines | Oracle
    • The colored bar in the icon indicates current processor activity. Red indicates high CPU usage, Green indicates low CPU usage. 
    • A green turtle icon indicates that a native hypervisor, such as Hyper-V, is running on the host.
    • Processing Cap: Note that limiting the execution time of the virtual CPUs may cause guest timing problems.

Guest VM

  • Create Fixed-Size Disks Instead of Dynamically Allocated Ones
  • The disk type/controller should be set as SSD
  • Disable 3D Acceleration in VM Settings
    • I think to use 3D acceleration you should use the VirtualBox driver.
    • And incidentally, 3D acceleration isn't just for 3D. It allows for faster (lower CPU overhead) graphics in general, which is important to cater for the trend to UHD+ high res (4K) displays.
  • Change Graphics Controller in VM Settings
    • VboxSVGA <--> VboxVGA <--> VMSVGA
    • use VMSVGA
    • https://forums.virtualbox.org/viewtopic.php?t=105010
      • VBoxVGA has been depreceated
      • VboxSVGA is recommended for Windows VMs, and VMSVGA is recommended for Linux VMs. VMSVGA is apparently provided as a compatibility provision for im/exported VMs to other hypervisors, if I remember correctly, so the VM OS won't have to endure a video card change. You're free to try anything you want, and some Linux VM users have anecdotally reported glitches with VMSVGA that go away with VboxSVGA.
      • How to Make Ubuntu 20.04 LTS VMs Smoother by Enabling 3D Acceleration on VirtualBox - 9to5Linux
        • A quick and painless tutorial to correctly enable 3D acceleration on Ubuntu 20.04 LTS and Ubuntu 18.04 LTS for VirtualBox virtual machines.
        • has a test to see if 3D acceleration is being used.
  • Disable Host I/O Cache in SATA Controller.
        Although the Host I/O Cache of the disk controller helps VirtualBox to run faster, in some cases it does not.
  • Install VirtualBox Guest Additions (optional)
    • for special drivers for better performance and allows stuff such as RAM monitoring
    • I would do this if it was just linux, might casue a mess but I am not an expert
    • i like to keep my installs vanilla
    • Remove & reinstall Guest Additions might help
  • Allocate more RAM to VM
  • Allocate more CPU to VM (Execution and cores)
        Generally not best to have a cap if you have enough resources
  • Increase the video memory
  • Suspend Instead of Shutting Down
        This is workaround and should not be a solution for better performance

Links

Network Settings

Where have the VirtualBox Drivers gone?

When you first setup a VirtualBox PC you might find the drivers are missing. These are not easy to find unless you know where they are.

  • The windows Files are on a iso file which might not be present until you install "Guest Additions"
  • C:\Program files\Oracle\VirtualBox\VBoxGuestAdditions.iso
  • So you mount this image which has the drivers.
  • see https://www.virtualbox.org/manual/ch04.html
  • I have also found that the drivers that are supplied do not cover all operating systems.

** Notes off the CD ? **

Oracle VM VirtualBox Guest Additions

  • Where have the Windows drivers gone?
    The Windows Guest Additions drivers were removed from this directory to save space on your hard drive. To get the files you have to extract them from the Windows Guest Additions installers:
  • To extract the 32-bit drivers to "C:\Drivers", do the following:
    VBoxWindowsAdditions-x86 /extract /D=C:\Drivers
  • For the 64-bit drivers:
    VBoxWindowsAdditions-amd64 /extract /D=C:\Drivers
  • Note: The extraction routine will create an additional sub directory with the selected architecture (x86 or amd64) to prevent mixing up the drivers.
  • To get further help with the command line parameters of the installer,
    type: VBoxWindowsAdditions-<arch> /?

Notes

  • The video drivers are present but the network card is not. The link below suggest changing the network card hardware type until you find one that works.
  • https://ubuntuforums.org/showthread.php?t=1106684  
    • "In the Virtualbox Control Panel thing (where you can specify your machines hardware configuration), you click on the network adapter category and then change the interface type. There are four to select from. Simply try a different interface type until one works. I didn't need to give windows any drivers for the PCnet-PCI II device (the screenshot shows the PCnew-FAST III device, and that's what I use on my home computer... this other persons computer...well, it probably would have worked too, but the I picked the PCI device out of the list of four available and it work with no issues or prompts to install any drivers). "
  • Try "PCnet-PCI II device"
  • Intel Pro/1000 MT (82540EM)

Driver Links

Troubleshooting

Cannot access Guest OS from Host when using Bridged networking, but it has internet

  • Guest OS can access the internet and can be pinged
  • All other PCs on the network can access the Guest OS
  • My router can ping the Guest OS
  • Wireless Limitations
    • Bridging over Wi-Fi has limitations on most hosts because not all wireless support promiscuous mode. 
    • Use Ethernet instead
  • The VM cannot ping the host, the host cannot ping the VM.
  • Things I have tried (that did not work for me)
    • Turned off all firewalls
    • Uninstalled
      • OpenVPN GUI
      • WireShark + all dependencies
    • Tried all `Promiscuous Modes`
    • Remove network hubs/switches between my PC and the router
    • Swapped to using my physical ethernet rather than a WiFi connection
      • NB: this might be a solution for you.
    • I have been using virtio-net, so i tried`Intel PRO/1000MT Desktop (8254OEM)`
    • in network devices, disabling `VirtualBox NDIS6 Bridged Networking Drive` on NICs that I was not using
    • Checked Hyper-V or the sandbox feature is not installed.
    • Reverted VirtualBox 7.2.16 to 7.1.18. I did a full uninstall and reboot before putting the old version back on.
    • I had 2 host-only adapters, so i reinstalled VirtualBox without them
    • Swapped Network profile type to private
      • Settings → Network & internet → Wi‑Fi or Ethernet → your connected network → Network profile type → Private
      • This allowed me to ping the host from an external PC.
    • Reset all network adapters through settings GUI
      • Although this did not work, it did cleaned up my network devices
    • Disabled IPv6 in the NICs
    • VirtualBox Bridged Networking – Guest Can't Reach Host at All (But Internet Works) - virtualbox.org - has a big list of things he tried and came to the same conclusion as I did.
  • Diagnostic commands
    • arp -a
      • this will give a list of mac against IP, including Guest OS
      • If you see something like: 
        10.0.0.190    xx-xx-xx-xx-xx-xx    dynamic
        • then the host can reach the VM at Layer 2, and we should investigate Windows filtering/firewall/routing.
    • arp -d
      • Empties the ARP cache
    • ping 10.0.0.190
      • obvious
    • ping 10.0.0.190 -S 10.0.0.166
      • ping the first IP starting its journey with the second IP
    • tracert -d 10.0.0.190
      • obvious
    • Get-NetConnectionProfile
      • If it shows Public for the adapter in question, that alone explains total inbound blocking, not just ICMP.
    • Test-NetConnection 10.0.0.190 -Port 22
      • can test any service with this powershell
    • Test-NetConnection 10.0.0.190 -InformationLevel Detailed
      • more advanced results of above
    • route print
      • Check the host’s route - The route should use the host’s normal LAN interface, not a VPN, Docker, WSL, or VirtualBox host-only interface.
    • route print 10.0.0.190
      • as above but only for the specified IP
    • Get-NetRoute -DestinationPrefix "10.0.0.190/32"
      • did not work for me
    • Get-NetAdapter | Format-Table ifIndex,Name,InterfaceDescription,Status,MacAddress,LinkSpeed
      • Nice table of adapters and their mac addresses
    • Get-NetAdapterBinding -Name "Ethernet 2" | Format-Table DisplayName,ComponentID,Enabled
      • List the NIC plugins (Eg Internet Protocol Version 4 (TCP/IPv4)
    • Get-NetFirewallProfile | Format-Table Name,Enabled,DefaultInboundAction,DefaultOutboundAction
      • check whether Windows is blocking the traffic
    • Get-NetFirewallRule -Direction Outbound -Enabled True -Action Block |  Select-Object DisplayName,Profile,Program
      • check whether Windows is blocking the traffic
    • Get-NetAdapterBinding -Name "Ethernet 2" | Where-Object {$_.Enabled -eq $true} | Format-Table DisplayName,ComponentID
      • not sure what this does
  • Cause
    • The network card is mangling the packets so they cannot be routed correctly. 
  • Solution(s)
    • These settings are only present on Ethernet cards so you cannot use a WiFi card to resolve this issue.
    • Edit the network card driver as follows (settings may vary)
        Default New setting Notes
      IPv4 Checksum Offload Rx & Tx Enabled Rx Enabled Allows ping
      Large Send Offload V2 (IPv4) Enabled Enabled Leave as is
      TCP Checkum Offload (IPv4) Rx & Tx Enabled Rx Enabled  
      UDP Checkum Offload (IPv4) Rx & Tx Enabled Rx Enabled Based on TCP results
      • You might need to apply these settings to IPv6

Error - Rapport Trusteer blocking VM from running

You are getting these errors

Failed to open a session for the virtual machine PM Cons.

The virtual machine 'PM Cons' has terminated unexpectedly during startup with exit code 1 (0x1).  More details may be available in 'C:\Users\Paul\VirtualBox VMs\PM Cons\Logs\VBoxHardening.log'.

Result Code: E_FAIL (0x80004005)
Component: MachineWrap
Interface: IMachine {85632c68-b5bb-4316-a900-5eb28d3413df}

Solutions

  • Solution 1
    • Uninstall vb
    • Reboot
    • Install vb
    • Set that service state to ...  (vboxdrv service ?)
  • Solution 2
    • Remove trusteer/rapport
    • Reboot and check
    • Remove other security products
    • Reboot and check

Notes

Windows XP will not boot completely or takes a long time

  • This is cause by `Core isolation --> Memory intergrity`.
  • Disable in windows and the Windows XP guest will boot correctly/

Nested VT-x/AMD-V Greyed out

  • TL;DR
    • I am running Windows 11 Pro
    • I disabled: Windows Security --> Device security --> Core isolation --> Memory integrity
    • I enabled the VT-x/AMD-V setting by using the command line: 
      VBoxManage modifyvm "<VM name>" --nested-hw-virt on

Nested virtualisation in VirtualBox can be unavailable for many reasons and we will work through them in a logical order below. The image blow shows you the setting we will be discussing

Hardware Support

As of VirtualBox 6.1.0, support for hosts that don't have VT-x or AMD-v have been dropped, and VT-x/AMD-v is required for all VMs.

Causes

  • Causes
    • Does your CPU support virtualisation.
      • It is very likely, as most modern processors have this feature.
      • VT-x / AMD-v has been added to CPUs thing since around 2010.
      • Intel 2nd Gen (VT-x, VT-d) + Ryzen 1000 series (AMD-V, IOMMU) and up = have the VT technologies.
    • Does Your CPU support Nested Virtualisation.
    • In the early days this was not a feature.
  • Checks
  • Notes
    • If you are running a VM in VirtualBox, then the answer is yes, but it might not support nested virtualisation.

Enabled in the BIOS?

  • Causes
    • Is it enabled in the BIOS?
    • Some BIOSes have a separate options for nested virtualisation.
  • Checks
    • Login to the BIOS and make sure all virtualisation options are on.

Check for Virtualisation support in Windows

So now we have verified our hardware supports the virtualisation features we need, we should now check Windows and VirtualBox.

Check VirtualBox mode (is there a green turtle)

  • This is a very simple check to see where the virtualisation is at for VirtualBox
  • Table 5-1 Virtual Machine Status Bar Icons - Working with Virtual Machines - You can see the icons up close here.
  • VirtualBox has 2 modes it can un its "Execution Engine" in, and this is easily shown by the CPU icon in the status bar at the bottom when you start a virtual machine up.
    • Execution Engine: VT-x/AMD-V
      • VirtualBox is using native hardware virtualization.
      • This is the "normal" mode and all CPU features are exposed to VirtualBox.
    • Execution Engine: native API
      • Some Hyper-V component is active, VirtualBox tries to use the Native Execution Manager (NEM) mode.
      • A green turtle icon indicates that a native hypervisor, such as Hyper-V, is running on the host.
      • This is where the reference to the green turtle comes from. Implication it is working but slower that it could.
      • This will mode runs slower than the native mode.
      • It allows you to keep core isolation on for more security but you cannot do nested virtualsation.
      • Using Hyper-V with Oracle VirtualBox - Advanced Topics | Oracle
        • Oracle VirtualBox can be used on a Windows host where Hyper-V is running but host systems might experience significant Oracle VirtualBox performance degradation.
        • Assuming Windows Hypervisor Platform is running, Oracle VirtualBox detects Hyper-V automatically and uses Hyper-V as the virtualization engine for the host system.
        • The CPU icon in the VM window status bar indicates that Hyper-V is being used.(i.e. it is a turtle)

What is causing Hyper-V to be running in Windows?

  • Hyper-V can be running for many reasons, not just for directly running VMs.
    • Hyper-V for directly running VMs (not sure what the name is)
    • Virtual Machine Plattform
    • Windows-Hypervisor-Platform
    • Windows Sandbox
    • Windows-Subsystem for Linux (WSL2)
    • Virtualization-based security (VBS/Core isolation)
      • This can get enabled when people upgrade their Windows 11.
    • Docker
  • There might be a way to get Nested Virtualisation working with Hyper-V and VirtualBox, I just have not found it yet.

Diagnostics

We can now use these techniques and software below to help identify the cause of Hyper-V to be running.

  • VBoxManage list hostinfo can be used to show exactly what features VirtualBox  can see 
    C:\Program Files\VirtualBox>VBoxManage list hostinfo
Host Information:

Host time: 2026-08-31T07:38:38.409000000Z
Processor online count: 8
Processor count: 8
Processor online core count: 4
Processor core count: 4
Processor supports HW virtualization: yes
Processor supports PAE: yes
Processor supports long mode: yes
Processor supports nested paging: yes
Processor supports unrestricted guest: no
Processor supports nested HW virtualization: no
Processor supports virt. vmsave/vmload: no
Processor#0 speed: unknown
Processor#0 description: 11th Gen Intel(R) Core(TM) i5-1135G7 @ 2.40GHz
Processor#1 speed: unknown
Processor#1 description: 11th Gen Intel(R) Core(TM) i5-1135G7 @ 2.40GHz
Processor#2 speed: unknown
Processor#2 description: 11th Gen Intel(R) Core(TM) i5-1135G7 @ 2.40GHz
Processor#3 speed: unknown
Processor#3 description: 11th Gen Intel(R) Core(TM) i5-1135G7 @ 2.40GHz
Processor#4 speed: unknown
Processor#4 description: 11th Gen Intel(R) Core(TM) i5-1135G7 @ 2.40GHz
Processor#5 speed: unknown
Processor#5 description: 11th Gen Intel(R) Core(TM) i5-1135G7 @ 2.40GHz
Processor#6 speed: unknown
Processor#6 description: 11th Gen Intel(R) Core(TM) i5-1135G7 @ 2.40GHz
Processor#7 speed: unknown
Processor#7 description: 11th Gen Intel(R) Core(TM) i5-1135G7 @ 2.40GHz
Memory size: 16103 MByte
Memory available: 5099 MByte
Operating system: Windows 11
Operating system version: 10.0.26200.8655

C:\Program Files\VirtualBox>     
    • The example above was run with Core Isolation on.
  • Windows Task Manager
    • Open up Task Manager
    • Got to the Performance tab
    • Select CPU
    • At the bottom right you will see a "Virtulaisation" setting displayed.
  • msinfo32
    • Shows Virtualisation-based security (VBS) is running
  • Coreinfo
    • CoreinfoEx64.exe (from Windows)
      • Shows the status of various CPU and windows features including if the Hypervisor is present.
    • coreinfo -v (from the command prompt) 
      D:\>coreinfo -v

Coreinfo v4.02 - Dump information on system CPU and memory topology
Copyright (C) 2008-2026 Mark Russinovich
Sysinternals - www.sysinternals.com


Note: Coreinfo must be executed on a system without a hypervisor running for
accurate results.
11th Gen Intel(R) Core(TM) i5-1135G7 @ 2.40GHz
Intel64 Family 6 Model 140 Stepping 1, GenuineIntel

Microcode signature: 000000BE
Processor signature: 000806C1

Maximum implemented CPUID leaves: 0000001B (Basic), 80000008 (Extended).
Maximum implemented address width: 48 bits (virtual), 39 bits (physical).

HYPERVISOR      *       Hypervisor is present
VMX             -       Supports Intel hardware-assisted virtualization
EPT             -       Supports Intel extended page tables (SLAT)
URG             -       Supports Intel unrestricted guest

D:\>
      • Information returned is limited to virtualisation.
      • As you can see here the hypervisor is present and the other virtualisation options are not available.
      • coreinfo without the -v switch will show a lot more info.
  • systeminfo.exe 
    Virtualization-based security: Status: Running
                               Required Security Properties:
                               Available Security Properties:
                                     Base Virtualization Support
                                     DMA Protection
                                     UEFI Code Readonly
                                     SMM Security Mitigations 1.0
                                     Mode Based Execution Control
                                     APIC Virtualization
                               Services Configured:
                                     Hypervisor enforced Code Integrity
                               Services Running:
                                     Hypervisor enforced Code Integrity
                               App Control for Business policy: Enforced
                               App Control for Business user mode policy: Off
                               Security Features Enabled:
Hyper-V Requirements:          A hypervisor has been detected. Features required for Hyper-V will not be displayed. 
    • In the results you will see these 2 sections that can be used to see if Hyper-V and Virtualization-based security (VBS/Core isolation) are running.
    • "A hypervisor has been detected. Features required for Hyper-V will not be displayed" - This means Hyper-V is running and this will prevent nested virtualization.
    • You can also get a shorter version using systeminfo | find "Virtualization"
  • bcdedit /enum
    • run this from the command prompt.
    • Look for hypervisorlaunchtype — Auto means Windows' hypervisor is set to launch at boot.
  • Rule out third-party hypervisors
    • If you run VMware Workstation, VirtualBox, Docker Desktop, or WSL2, any of those can install/enable a hypervisor layer too. Check: 
      Get-Service | Where-Object {$_.Name -match 'vmms|vmcompute|WSL|VBoxSVC|vmware'}
    • and Task Manager → Performance tab → CPU should show "Virtualization: Enabled" — not diagnostic on its own, but if Hyper-V/WSL2 is installed you'll also see it under: 
      Get-WindowsOptionalFeature -Online | Where-Object {$_.FeatureName -match 'Hyper-V|VirtualMachinePlatform|Containers'} 

Disable all instances of Hyper-V

If you go through the tutorials at the end they will direct you any additional processes you might need, but the one I did.

This allows the relevant CPU functions to be passed directly to VirtualBox rather than being grabbed by Hyper-V which in turn does not supply nested virtulisation.

  • Disable Core isolation
    • Windows Security --> Device security --> Core isolation --> Memory integrity
      • Modern Windows systems use this tech for security. Core Isolation and Memory Integrity give hypervisor-based protection. This makes threats like rootkits harder to execute.
      • But these features may conflict with some VM software. For example, VirtualBox can produce an error with Memory Integrity on. In that case, you can turn it off temporarily. But accept the security risk.
      • Keep Core Isolation off on dev machines. I leave it on for production systems. This balance gives both performance and safety.

Cannot enable VT-x/AMD-V in the VirtualBox GUI

We have to enable the setting using the command line. From the outside this does seem like a bug, but perhaps my new laptop is not new enough.

Fix

  • Enable the VT-x/AMD-V setting by using the command line: 
    VBoxManage modifyvm "<VM name>" --nested-hw-virt on

Cause

  • Virtualbox enable nested vtx/amd-v greyed out | Stack Overflow
    • From Ticket : This behavior is actually a known issue for your kind of CPU.
    • These models lack a certain feature called VMCS shadowing which improves nested HW virt performance tremendously, it will be terrible otherwise. That is the reason it is not available from the GUI.
    • VBoxManage however is meant as a tool to even make VM config changes which can break the VM and it is assumed the user knows what he or she is doing. Thats why it is possible to enable it from VBoxManage but performance is expected to be abysmal.
  • https://forums.virtualbox.org/viewtopic.php?f=1&t=98708&p=478598#p478598
    • The VirtualBox Manager allows the user to change the Enable Nested VT-x/AMD-V checkbox (under System > Processor), only if the VMCS Shadowing CPU feature is available, and prevents the user from doing so otherwise. (Actually, the VirtualBox Manager checks the availability of all 4 CPU features involved, but this distinction is not important here.) In consequence, VirtualBox V1 can run VirtualBox V2 with G2 efficiently.
    • The VBoxManage modifyvm <VM name> --nested-hw-virt on command enables Nested VT-x, irrespectively of the availability of the VMCS Shadowing CPU feature, and can therefore be used to circumvent the restrictions of the VirtualBox Manager method. This is equivalent to saying "I know what I'm doing!". In consequence, VirtualBox V1 cannot run VirtualBox V2 with G2 efficiently if the VMCS Shadowing CPU feature is not available.

Research Links

While researching this I came across these articles.

Questions

  • Is it possible to keep the Hyper-V running to allow for the benefits of core isolation but with the ability to use nested virtualisation? Speed is nto an issue.
Read 4344 times Last modified on Wednesday, 02 September 2026 15:53
Published in Virtual Machines
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