From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753817AbZDTI0W (ORCPT ); Mon, 20 Apr 2009 04:26:22 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751984AbZDTI0L (ORCPT ); Mon, 20 Apr 2009 04:26:11 -0400 Received: from mx2.redhat.com ([66.187.237.31]:48376 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751814AbZDTI0J (ORCPT ); Mon, 20 Apr 2009 04:26:09 -0400 Message-ID: <49EC3198.9070902@redhat.com> Date: Mon, 20 Apr 2009 11:26:00 +0300 From: Avi Kivity User-Agent: Thunderbird 2.0.0.21 (X11/20090320) MIME-Version: 1.0 To: Gerd Hoffmann CC: Anthony Liguori , Huang Ying , "kvm@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Andi Kleen Subject: Re: [PATCH] Add MCE support to KVM References: <1239155601.6384.3.camel@yhuang-dev.sh.intel.com> <49DE195D.1020303@redhat.com> <1239332455.6384.108.camel@yhuang-dev.sh.intel.com> <49E08762.1010206@redhat.com> <1239590499.6384.4016.camel@yhuang-dev.sh.intel.com> <49E337D7.5050502@redhat.com> <49EA515C.9000507@codemonkey.ws> <49EAE1F6.9050205@redhat.com> <49EC29D1.8040407@redhat.com> In-Reply-To: <49EC29D1.8040407@redhat.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Gerd Hoffmann wrote: >> Right now everything in the vcpu is emulated in the kernel. Everything >> else is emulated either in the kernel (irqchip) or in userspace. This >> makes things easier to understand, and is more future friendly if more >> cpu features become virtualized by hardware. >> >> While these are not compelling reasons, they at least lean the balance >> in favour of a kernel implementation. > > The xen pv-on-hvm drivers use an msr to indicate "please place the > hypercall page here". Handling that in kernel isn't an option IMHO. The contents of the hypercall page are vendor specific. This can be handled from userspace (though ideally we'd abstract the cpu vendor away). The Hyper-V hypercall page is more problematic, as it's specified to be an overlay; the page doesn't have to exist in guest RAM. -- error compiling committee.c: too many arguments to function