VMX (outside TXT) : disabled by bios

Question

When I boot into Ubuntu 20.04, I get

VMX (outside TXT) disabled by bios
Ubuntu20.10 :clean,... files,...blocks

It's little annoying

What this message means and how can I remove it?

score 38 · Accepted Answer · edited Apr 29 '25 at 23:47

Quick fix

Enable virtualization technology in BIOS.

Details

What this message means?

This message means actually what it says: VMX is disabled in BIOS.

VMX stands for Virtual Machine Extensions and it is a virtualization technology. More info on Wikipedia: X86 virtualization.

How can I remove it?

There is one quick way (workaround) to remove the message: Go to your BIOS settings and enable the virtualization technology. This BlueStacks article has some screenshots of how to do it in an Asus BIOS for both Intel and AMD processors.

More about the issue

The reason you probably didn't see this message up until now is that the logging of it got into a quite recent Linux kernel and it is an 'error' in journal. Apparently this annoys other people as well, there is a bug report on it already:

I found the solution for you here on openSUSE forums

If you feel that enabling a processor feature that you don't use just to make an error message go away is wrong then read on.

The reason why this issue is happening

Based on the discussion on the above mentioned SUSE thread and my other findings, it seems that this virtualization technology is used by the so-called KVM (Kernel-based Virtual Machine) which is built into the Linux kernel.

Upon boot, this generates an error in the logs that it cannot be initialized because the hardware capabilities are disabled in BIOS.

These are the actual commits that introduce this change:

Proper (not yet known) solution

Now if KVM itself is disabled in some way then I think that would also make this error message go away because the kernel would not even bother trying to load it. (Second commit above and mailing list discussion about it

I really did my homework and searched how to disable this kernel feature yet I could not find any relevant information how to do it and I am really not sure that it is a good idea to disable "ad hoc" kernel features just because they are unable to load themselves because of disabled hardware features.

score 1 · Answer 2 · edited Apr 29 '25 at 23:52

I had the same issue/error. In my case, it worked only after I emptied some space. OS could not boot itself.

I have only 250 GB of storage and memory was almost full, and I started to download a big file (~10 GB) and went to work. Laptop was on battery. After it turned off, I couldn't boot it anymore.

I entered the recovery mode, and tried to make a "repair broken packages". There I got the error related to "not enough space". It proposed me to delete some files and get 700 MB of space. It booted normally after this.