From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [Qemu-devel] Re: [PATCH 3/3] Add KVM support to QEMU Date: Wed, 29 Oct 2008 16:09:26 +0200 Message-ID: <49086E96.80809@redhat.com> References: <1225224814-9875-1-git-send-email-aliguori@us.ibm.com> <1225224814-9875-2-git-send-email-aliguori@us.ibm.com> <1225224814-9875-3-git-send-email-aliguori@us.ibm.com> <49078707.5000109@redhat.com> <49078955.2090109@codemonkey.ws> <5d6222a80810281604g39708040kf710725dce6413dd@mail.gmail.com> <4907A1FA.2060106@codemonkey.ws> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: qemu-devel@nongnu.org, Glauber Costa , Glauber Costa , kvm-devel , Gerd Hoffmann To: hollis@alumni.cmu.edu Return-path: Received: from mx2.redhat.com ([66.187.237.31]:35555 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752869AbYJ2OJk (ORCPT ); Wed, 29 Oct 2008 10:09:40 -0400 In-Reply-To: Sender: kvm-owner@vger.kernel.org List-ID: Hollis Blanchard wrote: > On Tue, Oct 28, 2008 at 6:36 PM, Anthony Liguori wrote: > >> Something I was thinking about this morning, and I think the first place >> where we'll definitely need a hook, is how to deal with >> kvm_load_registers(). I think there's overlap between KVM and the IO thread >> here. >> >> There are two reasons (I can think of) that most of the device model code >> can't run in conjunction with TCG. The first is that TCG may modify >> CPUState in a non-atomic way. The device model may need to access CPUState >> although there are very few places that it does. >> > > Out of curiosity, where are those places? > local apic -- needs to access interrupt disable flag acpi sleep -- halts the current processor, so tied to cpustate vmport -- bad ABI requires access to registers -- error compiling committee.c: too many arguments to function