From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751922AbdAYNPq (ORCPT ); Wed, 25 Jan 2017 08:15:46 -0500 Received: from mx1.redhat.com ([209.132.183.28]:59664 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751496AbdAYNPo (ORCPT ); Wed, 25 Jan 2017 08:15:44 -0500 Subject: Re: [patch 2/4] KVM: x86: add KVM_HC_CLOCK_OFFSET hypercall To: Marcelo Tosatti References: <20170124170938.909652059@redhat.com> <20170124171020.377051231@redhat.com> <1c6182a5-9894-74c5-23bd-872d7e9e20b5@redhat.com> <20170125125505.GC10780@amt.cnet> <20170125130627.GB13444@amt.cnet> Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Radim Krcmar , Richard Cochran , Miroslav Lichvar From: Paolo Bonzini Message-ID: Date: Wed, 25 Jan 2017 14:15:40 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.5.1 MIME-Version: 1.0 In-Reply-To: <20170125130627.GB13444@amt.cnet> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.29]); Wed, 25 Jan 2017 13:15:45 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 25/01/2017 14:06, Marcelo Tosatti wrote: >>> Well you don't know: we could implement it in case of HPET clocksource >>> hosts. >> But then the guest wouldn't have a TSC value to use, would it? >> >> Also, how would it use more padding? > I don't know, maybe pass the TSC and host HPET read in the structure? > (after exposing the HPET to the guest). > > Or maybe you want to sync CLOCK_MONOTONIC and that requires other data. > > Not sure. > > Just some space if new features are necessary. Fair enough. Paolo