From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dor Laor Subject: Re: recommended clock source Date: Mon, 03 Aug 2009 10:01:15 +0300 Message-ID: <4A768B3B.6050402@redhat.com> References: Reply-To: dlaor@redhat.com Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: kvm@vger.kernel.org To: Kent Tong Return-path: Received: from mx2.redhat.com ([66.187.237.31]:51599 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752316AbZHCHEu (ORCPT ); Mon, 3 Aug 2009 03:04:50 -0400 In-Reply-To: Sender: kvm-owner@vger.kernel.org List-ID: On 08/03/2009 04:52 AM, Kent Tong wrote: > Hi, > > It seems to be an unsettled issue, but, would any kind soul suggest the current > best practice for setting the clock in Ubuntu Linux and Windows guests? For Linux the best source clock is the kvm pv clock (exist from 2.6.27 and above). For windows, standard acpi HAL uses the rtc clock by default. As long as you use the -rtc-td-hack it won't drift. When the tsc is not stable on the host or the host cpu might get into deep sleep state (c2), you better use another source clock in the guest - for windows it should be the pmtimer (using the boot.ini). > > Thanks! > > -- > To unsubscribe from this list: send the line "unsubscribe kvm" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html