Re: QEMU vs KVM

[Avi Kivity <avi-atKUWr5tajBWk0Htik3J/w@public.gmane.org>]

gerryw-dHy0zPTSVEVBDgjK7y7TUQ@public.gmane.org wrote:
>
> Hello All,
>
> I am a bit unclear about the differences between QEMU and KVM. If I 
> understand correctly, QEMU can run in a mode on an x86 where it 
> executes user space code directly on the cpu without emulation. This 
> seems to be very similar to what KVM is doing with the exception of 
> using the virtualization capability of the cpu. I would think there 
> would be very little difference in performance between the two in this 
> case. Please forgive my ignorance, because I don't know that much 
> about the new VT cpus yet. What is the actual difference / objective 
> of the KVM project?

You're describing kqemu, not qemu.

Qemu is an emulator; it can emualte a large number of guests on a large 
number of hosts, albeit at fairly slow speeds.

kqemu is a "qemu accelerator" which can be used to speed up qemu 
emulation if the guest and host are the same.

kvm is a hardware virtualization system that is part of the Linux 
kernel.  While at present the only serious user is a modified qemu, it 
is not tied to qemu.  It is faster than either qemu of kqemu.  The 
downside is that it requires hardware virtualization extensions for 
fully virtualized guests.



-- 
error compiling committee.c: too many arguments to function


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