Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1764304AbZDCMSA (ORCPT ); Fri, 3 Apr 2009 08:18:00 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1760375AbZDCMRt (ORCPT ); Fri, 3 Apr 2009 08:17:49 -0400 Received: from mx2.redhat.com ([66.187.237.31]:57050 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757918AbZDCMRs (ORCPT ); Fri, 3 Apr 2009 08:17:48 -0400 Message-ID: <49D5FE42.5080100@redhat.com> Date: Fri, 03 Apr 2009 15:17:06 +0300 From: Avi Kivity User-Agent: Thunderbird 2.0.0.21 (X11/20090320) MIME-Version: 1.0 To: Ingo Molnar CC: Masami Hiramatsu , "H. Peter Anvin" , Frederic Weisbecker , Steven Rostedt , Ananth N Mavinakayanahalli , Andrew Morton , Andi Kleen , Jim Keniston , kvm@vger.kernel.org, systemtap-ml , LKML Subject: Re: [PATCH -tip 0/6 V4] tracing: kprobe-based event tracer References: <49D4F4B5.9040107@redhat.com> <20090403112639.GC31399@elte.hu> <49D5F80B.7000305@redhat.com> <20090403121202.GI31399@elte.hu> In-Reply-To: <20090403121202.GI31399@elte.hu> 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 Content-Length: 1222 Lines: 31 Ingo Molnar wrote: >> kvm has three requirements not needed by kprobes: >> - it wants to execute instructions, not just decode them, including >> generating faults where appropriate >> - it is performance critical >> - it needs to support 16-bit, 32-bit, and 64-bit instructions simultaneously >> >> If an arch/x86/ decoder/emulator gives me these I'll gladly switch >> to it. x86_emulate.c is high on my list of most disliked code. >> > > Well, this has to be driven from the KVM side as the kprobes use > will only be for decoding so if it's modified from the kprobes side > the KVM-only functionality might regress. > > So ... we can do the library decoder for kprobes purposes, and > someone versed in the KVM emulator can then combine the two. > Problem is, anyone versed in the kvm emulator will want to run as far away from this work as possible. -- I have a truly marvellous patch that fixes the bug which this signature is too narrow to contain. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/