1.2. KVM Hypervisor Requirements
The KVM hypervisor requires:
- an Intel processor with the Intel VT-x and Intel 64 virtualization extensions for x86-based systems; or
- an AMD processor with the AMD-V and the AMD64 virtualization extensions.
Virtualization extensions (Intel VT-x or AMD-V) are required for full virtualization. Enter the following commands to determine whether your system has the hardware virtualization extensions, and that they are enabled.
Procedure 1.1. Verifying virtualization extensions
Verify the CPU virtualization extensions are available
enter the following command to verify the CPU virtualization extensions are available:$
grep -E 'svm|vmx' /proc/cpuinfo
Analyze the output
- The following example output contains a
vmx
entry, indicating an Intel processor with the Intel VT-x extension:flags : fpu tsc msr pae mce cx8
vmx
apic mtrr mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm syscall lm constant_tsc pni monitor ds_cpl vmx est tm2 cx16 xtpr lahf_lm - The following example output contains an
svm
entry, indicating an AMD processor with the AMD-V extensions:flags : fpu tsc msr pae mce cx8 apic mtrr mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx mmxext
svm
fxsr_opt lm 3dnowext 3dnow pni cx16 lahf_lm cmp_legacy svm cr8legacy ts fid vid ttp tm stc
If thegrep -E 'svm|vmx' /proc/cpuinfo
command returns any output, the processor contains the hardware virtualization extensions. In some circumstances, manufacturers disable the virtualization extensions in the BIOS. If the extensions do not appear, or full virtualization does not work, see Procedure A.3, “Enabling virtualization extensions in BIOS” for instructions on enabling the extensions in your BIOS configuration utility.Ensure the KVM kernel modules are loaded
As an additional check, verify that thekvm
modules are loaded in the kernel with the following command:#
lsmod | grep kvm
If the output includeskvm_intel
orkvm_amd
, thekvm
hardware virtualization modules are loaded.
Note
The
virsh
utility (provided by the libvirt-client package) can output a full list of your system's virtualization capabilities with the following command:
# virsh capabilities