On Fri, Aug 01, 2014 at 11:15:29AM +0800, Gareth wrote: > Hi all > > What does '-enable-kvm' option mean? I have heard two versions of answers:
It's a shortcut for: $qemu -machine accel=kvm > a) guest OS would have /dev/kvm device and which could help vm in guest OS > (nested vm) That's nested KVM, which is enabled as a module option in the kernel module (on the host), eg: # modprobe kvm_intel nested=1 On AMD it's enabled by default. > b) use /dev/kvm and intel-vt on host OS which could help vm run more fast > than pure emulator. Nearly. It uses /dev/kvm on the host, which may or may not be implemented using Intel VT, or a variety of other techniques. You can also have fallbacks to software emulation (TCG): $qemu -machine accel=kvm:tcg Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming and virtualization blog: http://rwmj.wordpress.com virt-builder quickly builds VMs from scratch http://libguestfs.org/virt-builder.1.html
