From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: KVMClock skew Date: Wed, 07 Mar 2012 12:46:49 +0200 Message-ID: <4F573C99.4060107@redhat.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: kvm@vger.kernel.org To: Prateek Sharma Return-path: Received: from mx1.redhat.com ([209.132.183.28]:24190 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753205Ab2CGKqw (ORCPT ); Wed, 7 Mar 2012 05:46:52 -0500 In-Reply-To: Sender: kvm-owner@vger.kernel.org List-ID: On 02/20/2012 11:14 AM, Prateek Sharma wrote: > Hello all, > If i use KVMclock as the clock source in the guest, the guest clock > 'lags behind' the host clock by a big margin (1 second or more). The > time difference is not consistent, but i am seeing it in the range of > 1-2 seconds. > Is this by design? No. > I need an simple clocksource which is consistent > between the host and the guest. Is using HPET in the guest a good idea > for this, or is that also emulated by KVM ? > It is also emulated. The discrepancy may be due to ntp adjusting the time, and kvmclock not compensating. Are you running ntp on your host? What about the guest? -- error compiling committee.c: too many arguments to function