QEMU和KVM问题

Question

I tried to install qemu, but I should install the kvm first, and I have checked that my cpu supports virtualization, so I don't know why. Here is the error, when I input kvm.

open /dev/kvm: No such file or directory
Could not initialize KVM, will disable KVM support

And a new window for qemu comes out, but the boot failed....could not read the boot disk, could not read from CDROM(code 0003)

What can I do?

Answer 1

First, check if your CPU support VMX or SVM having a look at /proc/cpuinfo. If yes, you have to load the KVM kernel modules:

modprobe kvm-amd  #if you have AMD
modprobe kvm-intel  #if you have Intel

Then Qemu/Kvm command should start without complaining about /dev/kvm. If you still have problems, may be virtualization is disabled in the BIOS. I had some machines that reportes virtualization support in the /proc/cpuinfo but it was disabled in the BIOS.

Then to boot KVM from a ISO image:

kvm -cdrom img.iso -hda disk.img -boot d

Answer 2

请尝试“dmesg | grep kvm”找到原因

Answer 3

Try to use this command sudo modprobe kvm-intel . You lacked privilege to insert KVM modules.

Answer 4

The first things to check is that your CPU has virtualization extensions and that the extensions are enabled in the BIOS/EUFI menus. These extensions are required in order to run KVM. Pretty much all modern AMD 64bit cpus will have it. Some older/lower-end Intel processes do not have it, but most will.

egrep -o 'vmx|svm' /proc/cpuinfo

'vmx' will show up for Intel. 'svm' for AMD.

If your cpu supports the extensions the next thing to check is your BIOS/EUFI settings. Many times these extensions are disabled by default. You will want to look for the 'chipset' or 'cpu' settings and it should mention something about 'virtualization'. Make sure that those settings are enabled.

After that is done then you should have KVM modules inserted automatically after a reboot. If they don't then try the 'modprobe kvm-amd' or 'modprobe kvm-intel' as suggested by Diego Woitasen. Check the 'dmesg |grep kvm' output as well.