From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752818Ab0GEGYL (ORCPT ); Mon, 5 Jul 2010 02:24:11 -0400 Received: from mx1.redhat.com ([209.132.183.28]:64738 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751754Ab0GEGYK (ORCPT ); Mon, 5 Jul 2010 02:24:10 -0400 Date: Mon, 5 Jul 2010 09:23:57 +0300 From: Gleb Natapov To: Xiao Guangrong Cc: Avi Kivity , Marcelo Tosatti , LKML , KVM list , Jin Dongming Subject: Re: [PATCH v2] KVM: IOAPIC: only access APIC registers one dword at a time Message-ID: <20100705062357.GH4689@redhat.com> References: <4C2D6D4B.5060309@cn.fujitsu.com> <4C2D95EA.6080209@np.css.fujitsu.com> <4C2D975A.2050704@cn.fujitsu.com> <4C2D9C8C.8060401@cn.fujitsu.com> <4C2F0CC1.6020808@redhat.com> <4C3155BA.4070903@cn.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4C3155BA.4070903@cn.fujitsu.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jul 05, 2010 at 11:47:06AM +0800, Xiao Guangrong wrote: > > There might be guests that use incorrect access despite the > > documentation; if real hardware supports it, it should work. So we need > > to start with just a warning, and allow the access. Later we can drop > > the invalid access. > > If the OS contravene the spec, i thinks it's the OS's bug, also, i have tested some versions > windows/linux guests, it's no broken, can we directly drop the other wide access? > If reality contradicts spec we should emulate reality. I vaguely remember some guest using memcpy on apic page for instance. -- Gleb.