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Your CPU does not support KVM extention

asked 2019-08-24 11:26:27 -0500

anonymous user


updated 2019-08-24 19:28:57 -0500

On my host machine, I checked this command egrep -c '(vmx|svm)' /proc/cpuinfo and I got 12 which means KVM acceleration can be used. But In my Controller Node and Compute Node, I checked the same command but I got 0 which means KVM acceleration cannot be used. why this occurred? I am using VirtualBox to install multiple nodes

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answered 2019-08-24 18:22:07 -0500

You don't say it very clearly, but I understand that your cloud is implemented on VirtualBox VMs.

I wanted to say that VirtualBox does not support nested virtualization, i.e. guest CPUs don't inherit the virtualization features of their hosts, but VBox 6 seems to support it: I didn't check if VT-x has been implemented by now.

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Well the problem is that I am using VirtualBox 6.0.6 but I checked egrep -c '(vmx|svm)' /proc/cpuinfo still got 0 on my controller node and compute node.

Harry996 gravatar imageHarry996 ( 2019-08-24 19:27:12 -0500 )edit

Use the VirtualBox documentation to find out what you have to do. Personally, I learned about this new feature an hour ago and haven't used it yet. Perhaps Intel CPUs are not supported yet?

Alternatively, VMware products do support nested virtualization as far as I know. Again, I have not tried it.

Bernd Bausch gravatar imageBernd Bausch ( 2019-08-24 19:44:51 -0500 )edit


Oracle VM VirtualBox supports nested virtualization on host systems that run AMD CPUs

So, if your host uses Intel CPUs, VirtualBox is not for you.

Bernd Bausch gravatar imageBernd Bausch ( 2019-08-24 19:48:03 -0500 )edit

You're right! I am using Intel CPUs. But why I could run an instance in devstack installed another VM on VirtualBox but the multiple nodes could not.

Harry996 gravatar imageHarry996 ( 2019-08-24 19:58:41 -0500 )edit

Devstack configures qemu instead of kvm. I think that it automatically configures kvm when it detects that the CPU supports virtualization.

Bernd Bausch gravatar imageBernd Bausch ( 2019-08-24 21:24:27 -0500 )edit

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Asked: 2019-08-24 11:26:27 -0500

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Last updated: Aug 24 '19