check if VT-x is activated without having to reboo

Question

I have a laptop with Intel Core i5 M 450 @ 2.40GHz which apparently has VT-x but not VT-d. I have Ubuntu 12.04 32bit but would like to have a virtual 64bit terminal-based Linux running on it. How do I know if the BIOS has this VT-x feature activated without having to reboot?

Answer 1

You can use

sudo kvm-ok

from cpu-checker. On Intel, which has the most complicated logic, kvm-ok checks that if bit 0 of rdmsr 0x3a (the lock bit) is set, bit 2 (which allows virt use outside of SMX mode, something to do with trusted boot) must also be set. If the output of rdmsr 0x3a is anything but 1 or 3, you will be able to use kvm. kvm will set bit 2 of the msr if necessary, I expect virtualbox and the rest have the same logic.

Answer 2

Install cpu-checker and run "kvm-ok"

If the CPU is enabled, you should see something like:

INFO: /dev/kvm exists
KVM acceleration can be used

othewise

INFO: /dev/kvm does not exist
HINT:   sudo modprobe kvm_intel
INFO: Your CPU supports KVM extensions
INFO: KVM (vmx) is disabled by your BIOS
HINT: Enter your BIOS setup and enable Virtualization Technology (VT),
   and then hard poweroff/poweron your system
KVM acceleration can NOT be used