From mboxrd@z Thu Jan  1 00:00:00 1970
From: Zachary Amsden <zamsden@redhat.com>
Subject: Re: qemu-kvm 0.12.3, Slackware 13 host and Windows XP guest - time
 	drift a lot
Date: Wed, 17 Mar 2010 12:45:10 -1000
Message-ID: <4BA15B76.2080203@redhat.com>
References: <1f0fa7ae1003171222i37b81306ye860d40390511459@mail.gmail.com>	 <4BA12E9C.4030601@redhat.com> <1f0fa7ae1003171517hec6bf0fj1f9bdc17b2566290@mail.gmail.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=ISO-8859-1;
	format=flowed
Content-Transfer-Encoding: QUOTED-PRINTABLE
Cc: kvm@vger.kernel.org
To: =?ISO-8859-1?Q?Thomas_L=F8cke?= <thomas.granvej6@gmail.com>
Return-path: <kvm-owner@vger.kernel.org>
Received: from mx1.redhat.com ([209.132.183.28]:63426 "EHLO mx1.redhat.com"
	rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP
	id S1755393Ab0CQWpO (ORCPT <rfc822;kvm@vger.kernel.org>);
	Wed, 17 Mar 2010 18:45:14 -0400
In-Reply-To: <1f0fa7ae1003171517hec6bf0fj1f9bdc17b2566290@mail.gmail.com>
Sender: kvm-owner@vger.kernel.org
List-ID: <kvm.vger.kernel.org>

On 03/17/2010 12:17 PM, Thomas L=F8cke wrote:
> On Wed, Mar 17, 2010 at 8:33 PM, Zachary Amsden<zamsden@redhat.com>  =
wrote:
>   =20
>> What's your host CPU load get up to.  You only have a single core?
>>     =20
> Dual core.
>
> If I only run a single Windows VM, the host load is pretty low. Sure
> it goes up a bit when for example copying a file, but it's nothing
> serious. It's not getting hammered in any way.
>
>   =20
>> Including -rtc-td-hack ?
>>     =20
> Yup, tried that as per suggested by one of the #kvm users. Didn't fix
> it. But come to think of it, I didn't change any of the other options=
=2E
> Should I have dropped -localtime and/or -tdf options? I will try agai=
n
> tomorrow.
>   =20

-rtc localtime

is required for Windows to get the proper RTC time, and -tdf should hav=
e=20
no effect on Windows guests.

You might try

-rtc localtime,clock=3Dhost,driftfix=3Dslew

>
>   =20
>> As always, make sure you are running the latest and greatest modules=
, those
>> matter even more than the kernel, and check for any warning messages=
 in
>> dmesg and qemu output.
>>     =20
>
> But don't the latest kvm modules come with the kernel? So if I compil=
e
> a new kernel, the kvm modules should be updated too, yes?
>
> I will try the latest qemu-kvm.
>   =20

I use git://git.kernel.org/pub/scm/virt/kvm/kvm-kmod.git and track a 2.=
6=20
kernel branch directly so I always have latest module source regardless=
=20
of host kernel.

Zach