Re: [Qemu-devel] qemu-kvm faster that qemu?

[Anthony Liguori]

On 08/25/2010 02:37 PM, walt wrote:
> Hi qemu team,
>
> I just discovered that qemu now offers kvm support, so I decided to
> compare it to qemu-kvm.
>
> I'm running the latest git versions of both programs on an AMD64
> host running the latest kernel from Linus.git.
>
> The guest is Windows 7 on a qcow2 disk image and one kvm64 cpu.
>
> Using the same qcow2 image for both qemu and qemu-kvm, I find that
> qemu-kvm boots to the Win7 login prompt in 25 seconds, but qemu
> with kvm enabled takes about 45 seconds.


make sure you build qemu with --enable-io-thread.  Also, what's your 
full command line?

Regards,

Anthony Liguori

> Is this an expected outcome, or must I be doing something wrong
> with qemu?
>
> BTW, I tried reverting the qcow2 patch being discussed in another
> thread but it made no difference.  Perhaps there's not much writing
> to disk during bootup?
>
> Thanks!