From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marcelo Tosatti Subject: Re: [PATCH v2 1/2] Do not register kvmclock savevm section if kvmclock is disabled. Date: Mon, 6 Dec 2010 19:55:58 -0200 Message-ID: <20101206215558.GB15299@amt.cnet> References: <1291644227-22923-1-git-send-email-glommer@redhat.com> <1291644227-22923-2-git-send-email-glommer@redhat.com> <20101206210401.GB14704@amt.cnet> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: kvm@vger.kernel.org, qemu-devel@nongnu.org, avi@redhat.com To: Glauber Costa Return-path: Received: from mx1.redhat.com ([209.132.183.28]:8508 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752325Ab0LFV5S (ORCPT ); Mon, 6 Dec 2010 16:57:18 -0500 Content-Disposition: inline In-Reply-To: <20101206210401.GB14704@amt.cnet> Sender: kvm-owner@vger.kernel.org List-ID: On Mon, Dec 06, 2010 at 07:04:01PM -0200, Marcelo Tosatti wrote: > On Mon, Dec 06, 2010 at 09:03:46AM -0500, Glauber Costa wrote: > > Usually nobody usually thinks about that scenario (me included and specially), > > but kvmclock can be actually disabled in the host. > > > > It happens in two scenarios: > > 1. host too old. > > 2. we passed -kvmclock to our -cpu parameter. > > > > In both cases, we should not register kvmclock savevm section. This patch > > achives that by registering this section only if kvmclock is actually > > currently enabled in cpuid. > > > > The only caveat is that we have to register the savevm section a little bit > > later, since we won't know the final kvmclock state before cpuid gets parsed. > > What is the problem of registering the section? Restoring the value if > the host does not support it returns an error? > > Can't you ignore the error if kvmclock is not reported in cpuid, in the > restore handler? > > Also, please generate against uq/master. Sorry, this is not upstream yet, so ignore the uq/master part.