What's the differences between Xen, QEMU and KVM?

virtualization qemu xen kvm
Xorax picture Xorax · Apr 25, 2012 · Viewed 49.7k times · Source

I know QEMU is used by Xen, and KVM is a fork of QEMU.

So, KVM includes that Xen adds to QEMU ? What is the name ?

Thanks

Answer

Todd Deshane picture Todd Deshane · Apr 26, 2012

QEMU is a powerful emulator, which means that it can emulate a variety of processor types.

Xen uses QEMU for HVM guests, more specifically for the HVM guest's device model. The Xen-specific QEMU is called qemu-dm (short for QEMU device model)

QEMU uses emulation; KVM uses processor extensions (HVM) for virtualization.

Both Xen and KVM merge their various functionality to upstream QEMU, that way upstream QEMU can be used directly to accomplish Xen device model emulation, etc.

Xen is unique in that it has paravirtualized guests that don't require hardware virtualization.

Both Xen and KVM have paravirtualized device drivers that can run on top of the HVM guests.

Related questions

How to convert flat raw disk image to vmdk for virtualbox or vmplayer?

I have some old images of old Linux filesystems in flat file format. they can be used by Bochs, but I need to run them with Virtual Box. Virtual Box cannot use images in this format, so I need to …

Read More
qemu KVM kernel module no such file or directory

I am currently taking an operating systems class and I need to use qemu to run a small operating system that my professor provided. I am trying to use qemu within an ubuntu 12.04 virtual machine on virtualbox on my macbook …

Read More
How to set boot order on KVM (libvirt/virsh)?

How would you set the boot order on KVM when using libvirt/virsh? (Either via config or command)

Read More