If your system supports hardware virtualisation
That error message means that qemu is trying to use kvm for virtualisation and cannot access the kvm kernel device. You will probably find that the file /dev/kvm
is not present.
Your host needs the kvm
kernel module loaded.
You can check if the module is loaded by running:
lsmod|grep kvm
If that produces no output, you could execute the following command to load the module:
sudo modprobe kvm
If you are then able to run qemu, you can make the change persistent by adding the following line to the file /etc/modules
:
kvm
Otherwise
You can check the output of /proc/cpuinfo field flags for vt
or lbrv
or svm
, if none of those are present virtualisation may not be supported.
You may also need to first enable virtualisation in your BIOS.
If your computer does not support hardware virtualisation, this will still not work.
In which case you may need to force emulation, for example:
qemu -machine pc,accel=tcg (...other options...)
Note
This behaviour may be a function of the version of qemu and Ubuntu you are using; on Debian wheezy amd64 qemu seems to automatically fallback if kvm is not loaded.
[Edit - notes about hardware virtualisation, etc.]