From mboxrd@z Thu Jan 1 00:00:00 1970 From: Zachary Amsden Subject: Re: TSC host kernel message with kvm.git as host kernel and qemu-kvm.git as userspace Date: Thu, 21 Oct 2010 10:56:18 -1000 Message-ID: <4CC0A8F2.1050501@redhat.com> References: <1287690549.3125.27.camel@freedom> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Cc: KVM mailing list To: Lucas Meneghel Rodrigues Return-path: Received: from mx1.redhat.com ([209.132.183.28]:37802 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753420Ab0JUU4U (ORCPT ); Thu, 21 Oct 2010 16:56:20 -0400 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id o9LKuKgK028816 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Thu, 21 Oct 2010 16:56:20 -0400 In-Reply-To: <1287690549.3125.27.camel@freedom> Sender: kvm-owner@vger.kernel.org List-ID: On 10/21/2010 09:49 AM, Lucas Meneghel Rodrigues wrote: > Hi folks, > > I was doing some work at one of our host machines, the one that runs > upstream (Fedora 14, kvm.git as the kernel and qemu-kvm.git as > userspace), and I noticed the kernel message: > > kvm: unreliable cycle conversion on adjustable rate TSC > kvm: SMP vm created on host with unstable TSC: guest TSC will not be > reliable > Yes, the message is a warning; without TSC trapping, SMP VMs will have unreliable TSC. In this case, you are advised to use kvmclock or another non-TSC clocksource in the guest. Zach