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Parag Katoch
Asked: 2020-12-05 04:53:43 +0800 CST

VMX (outside TXT) : disabled by bios

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I got

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

when I boot into Ubuntu 20.04.

It's little annoying

What this message means and how can I remove it?

boot 20.10

1 Answers

  1. Best Answer

    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 here.

    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 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

    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: https://github.com/torvalds/linux/commit/ef4d3bf19855641fc8a1f621eaf06e2a2bb872b https://github.com/torvalds/linux/commit/bb02e2cb715a3f3552dbe765ea4a07799e4dff43

    Proper (not yet known) solution

    Now if KVM itself is disabled in some way than 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.

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