From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Kiszka Subject: Re: [PATCH 6/6] KVM: x86: Emulator support for TF Date: Tue, 23 Feb 2010 13:03:42 +0100 Message-ID: <4B83C41E.30207@siemens.com> References: <20100223095553.GC29041@redhat.com> <4B83A9B1.2060103@siemens.com> <20100223102620.GF29041@redhat.com> <4B83AFE1.3070905@siemens.com> <20100223110054.GI29041@redhat.com> <4B83BC53.6090102@siemens.com> <4B83BEF8.5050503@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: Gleb Natapov , Marcelo Tosatti , kvm To: Avi Kivity Return-path: Received: from goliath.siemens.de ([192.35.17.28]:17517 "EHLO goliath.siemens.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751861Ab0BWMEB (ORCPT ); Tue, 23 Feb 2010 07:04:01 -0500 In-Reply-To: <4B83BEF8.5050503@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: Avi Kivity wrote: > On 02/23/2010 01:30 PM, Jan Kiszka wrote: >>> How to detect that emulation is complete? emulate_instruction() should >>> return EMULATE_DONE in this case. >>> >> ...*and* RIP moved forward. >> > > A branch or rep instruction can successfully execute and not change rip. > > Btw, do we expect a #DB on every iteration of rep? In this case we need > to modify the code, currently we'll batch rep;ins and rep;outs up to a > page's worth. Right, TF triggers after each rep step. So we need to break this up when tracing is on. That's now definitely something we need a deeper emulator change. Jan -- Siemens AG, Corporate Technology, CT T DE IT 1 Corporate Competence Center Embedded Linux