We already knew how to check if a Linux OS is 32 bit or 64 bit and how to find if a Linux system is physical or virtual machine. Today, we are going to learn yet another useful topic i.e. how to find if a CPU supports virtualization technology (VT) or not. This is the first step that you should do before installing virtualization applications such as KVM, Proxmox, Gnome Boxes, Quickemu, VirtualBox and VMWare workstation to run virtual machines on your Linux system. Now let us go ahead and find out if our CPU supports VT or not.
Table of Contents
Find If A CPU Supports Virtualization Technology (VT) In Linux
We can check if our CPU supports VT in various methods. Here I've listed four methods.
Method 1: Using egrep command
Egrep is one of the variant of Grep command line utility which is used to search text files with regular expressions.
To find out if your CPU supports VT using egrep command, run:
$ egrep "(svm|vmx)" /proc/cpuinfo
This command will grep /cpu/procinfo
file and display if the CPU supports VT or not.
Sample output:
You will get either "vmx" (Intel-VT technology) or "svm" (AMD-V support) in the output.
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx rdtscp lm constant_tsc arch_perfmon pebs bts rep_good nopl xtopology nonstop_tsc cpuid aperfmperf pni pclmulqdq dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm pcid sse4_1 sse4_2 x2apic popcnt tsc_deadline_timer xsave avx lahf_lm epb pti tpr_shadow vnmi flexpriority ept vpid xsaveopt dtherm arat pln pts
[...]
Since the output is very long, it might be bit hard to find the words "vmx" or "svm". No worries! You can distinguish those terms with colors like below.
$ egrep --color -i "svm|vmx" /proc/cpuinfo
Sample output:
If you don't get any output, it means that your system doesn't support virtualization.
Please note that these CPU flags (vmx or svm) in the /proc/cpuinfo
file indicates that your system will support VT. In some CPU models, the VT support might be disabled in the BIOS, by default. In such cases, you should check your BIOS settings to enable VT support.
Method 2 - Using lscpu command
The lscpu
command is used to display the information about your CPU architecture. It gathers information from sysfs
, /proc/cpuinfo
file and displays the number of CPUs, threads, cores, sockets, and Non-Uniform Memory Access (NUMA) nodes of your host system.
To find out if the VT support is enabled or not, simply run:
$ lscpu
Method 3 - Using Cpu-checker utility
Cpu-checker is yet another useful utility to test your CPU for virtualization support. As far as I searched on the web, this utility is available only for Ubuntu-based systems. To install it, run:
$ sudo apt-get install cpu-checker
Once cpu-checker package is installed, run the following command to check whether VT support is enable or not:
$ kvm-ok
If your CPU supports VT, you will get the following output:
INFO: /dev/kvm exists KVM acceleration can be used
If your CPU doesn't support VT, you will see an output something like below.
INFO: Your CPU does not support KVM extensions KVM acceleration can NOT be used
Method 4 - Using virt-host-validate tool
This tool is specifically for RHEL based distros like CentOS and Scientific Linux. The libvirt-client package provides virt-host-validate binary. So you need to install "libvert-client" package to use this tool.
$ sudo yum install libvirt-client
Now, run "virt-host-validate" command to find if VT is enabled or not in your RHEL-based systems.
$ sudo virt-host-validate
If you get pass for all results, your system supports VT.
QEMU: Checking for hardware virtualization : PASS
QEMU: Checking if device /dev/vhost-net exists : PASS
QEMU: Checking if device /dev/net/tun exists : PASS
QEMU: Checking for cgroup 'memory' controller support : PASS
QEMU: Checking for cgroup 'memory' controller mount-point : PASS
QEMU: Checking for cgroup 'cpu' controller support : PASS
QEMU: Checking for cgroup 'cpu' controller mount-point : PASS
QEMU: Checking for cgroup 'cpuacct' controller support : PASS
QEMU: Checking for cgroup 'cpuacct' controller mount-point : PASS
QEMU: Checking for cgroup 'cpuset' controller support : PASS
QEMU: Checking for cgroup 'cpuset' controller mount-point : PASS
QEMU: Checking for cgroup 'devices' controller support : PASS
QEMU: Checking for cgroup 'devices' controller mount-point : PASS
QEMU: Checking for cgroup 'blkio' controller support : PASS
QEMU: Checking for cgroup 'blkio' controller mount-point : PASS
QEMU: Checking for device assignment IOMMU support : PASS
LXC: Checking for Linux >= 2.6.26 : PASS
LXC: Checking for namespace ipc : PASS
LXC: Checking for namespace mnt : PASS
LXC: Checking for namespace pid : PASS
LXC: Checking for namespace uts : PASS
LXC: Checking for namespace net : PASS
LXC: Checking for namespace user : PASS
LXC: Checking for cgroup 'memory' controller support : PASS
LXC: Checking for cgroup 'memory' controller mount-point : PASS
LXC: Checking for cgroup 'cpu' controller support : PASS
LXC: Checking for cgroup 'cpu' controller mount-point : PASS
LXC: Checking for cgroup 'cpuacct' controller support : PASS
LXC: Checking for cgroup 'cpuacct' controller mount-point : PASS
LXC: Checking for cgroup 'cpuset' controller support : PASS
LXC: Checking for cgroup 'cpuset' controller mount-point : PASS
LXC: Checking for cgroup 'devices' controller support : PASS
LXC: Checking for cgroup 'devices' controller mount-point : PASS
LXC: Checking for cgroup 'blkio' controller support : PASS
LXC: Checking for cgroup 'blkio' controller mount-point : PASS
If your system doesn't support VT, you will see an output like below.
QEMU: Checking for hardware virtualization : FAIL (Only emulated CPUs are available, performance will be significantly limited)
[...]
Conclusion
In this guide, we have discussed various methods to find if a CPU supports VT or not. As mentioned already, it is mandatory to verify if your processor supports hardware virtualization before installing any hypervisors.