How do I enable hardware virtualization technology (VT-x) for use in Virtualbox?

Question

So I am trying to run Ubuntu in a virtualbox but on installing 12.10 from the .iso I was greeted by a warning telling me that audio wouldn't work then I pressed next and this popped up:

Failed to open a session for the virtual machine Tux 3
VT-x features locked or unavailable in MSR
(VERR_VMX_MSR_LOCKED_OR_DISABLED)
Details

Result Code: 
E_FAIL (0x80004005)
Component: 
Console
Interface: 
IConsole {db7ab4ca-2a3f-4183-9243-c1208da92392}

And then it doesn't work.

I assigned 4GB of my 8GB to Ubuntu, 100 dynamically allocated GB of space, and 12MB of graphics memory. I'm running an Asus p8z77 V LX mobo with an Intel i5 3550 processor.

Downloaded 12.04.2 on my PC and tried again. Still getting the same message.

Solution 1

Before changing BIOS settings we may want to see if hardware virtualization (VT-x for Intel, AMD-V for AMD processors) is supported by our CPU.

From a terminal issue

grep --color vmx /proc/cpuinfo ## for an Intel processor
grep --color svm /proc/cpuinfo ## for an AMD processor

If virtualization was supported the flag vmx (for Intel CPUs) or svm (for AMD CPUs) will be colored.

In case the CPU supports hardware virtualization, we need to enable it in the computer BIOS to be able to use it.

Also read How to determine if CPU VT extensions are enabled in bios? for other approaches.

Enter the BIOS (often pressing Del or F12 while booting) and see with the manual how it is named there. Each BIOS appears to have a different name fror this. Search for Virtualization, Virtualization Technology (VT-x), SVM, VMX, or similar, here shown for an Award BIOS:

For an example screenshot of an Asus EFI-BIOS see this answer on SU.

Set this entry to Enabled in case it was not done yet. Some BIOS need a cold boot (i.e. boot from power off state) to be able to use hardware virtualization.

Hardware virtualization can then be chosen in the virtual machine's System -> Acceleration settings:

By this the VM uses hardware virtualization for optimal performance. We would even be able to run a 64-bit guest OS on a 32-bit host for testing.

Solution 2

I had the same exact error, and fixed it by dropping the 4095 GB to 3072 MB (3 GB). This is because it was 32-bit. I think the more than 3 GB is throwing it off.

Comments

[Admin]

Related: Cannot install Ubuntu in VirtualBox due to " this kernel requires an x86-64 CPU, but only detects an i686 CPU, unable to boot" error

[Ads20000]

I still get this problem. My 'vmx' is coloured when running the command above and I've gone and enabled 'virtualisation' in the BIOS as well.

[Boris Churzin]

After changing the bios setting to ON, don't just restart your computer, turn it off and then on! Apparently just restart doesn't do the thing :/

[Kaushik Acharya]

In my case 'vmx' was colored. But when I checked BIOS 'virtualisation' wasn't enabled. So it seems checking terminal command suggested by Takkat isn't a confirmation that 'virtualisation' is enabled.

[Takkat]

@KaushikAcharya: thank you for pointing this out.. The terminal commands for CPU flags were suggested by an edit from another user. I admit I had not tested them thoroughly - my bad. Nevertheless they are useful to see whether the CPU in our system does support virtualization at all.

[nealmcb]

See more details on distinguishing cpu support from bios support via th kvm-ok command in the qemu-kvm package. Read more at askubuntu.com/questions/103965/…

[user1350992]

Just in case anyone has an HP computer, VT-x is in BIOS/Security/System Security.

[PromInc]

I had the same experience - despite the articles I was finding saying that the BIOS needs to be modified, the issue apparently lied in that I tried upping the memory for the virtual machine and it apparently was more than the 32-bit system could handle.

[jave.web]

@BorisChurzin solution actually worked - the computer must have to be firstly completely turned off/shut down after saving the bios settings

[Takkat]

@jave.web: thanks for the feedback - I edited this into the answer as it appears to affect many people.