From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marcelo Tosatti Subject: Re: [PATCH 2/2] KVM: Trace emulated instructions Date: Tue, 6 Apr 2010 15:52:27 -0300 Message-ID: <20100406185227.GA6971@amt.cnet> References: <1269529376-17650-1-git-send-email-avi@redhat.com> <1269529376-17650-3-git-send-email-avi@redhat.com> <20100405184438.GA7141@amt.cnet> <4BBA5838.6080603@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: kvm@vger.kernel.org, Gleb Natapov To: Avi Kivity Return-path: Received: from mx1.redhat.com ([209.132.183.28]:55682 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757519Ab0DFSxB (ORCPT ); Tue, 6 Apr 2010 14:53:01 -0400 Received: from int-mx02.intmail.prod.int.phx2.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id o36Ir07H030397 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Tue, 6 Apr 2010 14:53:00 -0400 Content-Disposition: inline In-Reply-To: <4BBA5838.6080603@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On Tue, Apr 06, 2010 at 12:38:00AM +0300, Avi Kivity wrote: > On 04/05/2010 09:44 PM, Marcelo Tosatti wrote: > >On Thu, Mar 25, 2010 at 05:02:56PM +0200, Avi Kivity wrote: > >>Log emulated instructions in ftrace, especially if they failed. > >Why not log all emulated instructions? Seems useful to me. > > > > That was the intent, but it didn't pan out. I tried to avoid > double-logging where an mmio read is dispatched to userspace, and > the instruction is re-executed. > > Perhaps we should split it into a decode trace and execution result > trace? Less easy to use but avoids confusion due to duplication. I don't think duplication introduces confusion, as long as one can see rip on the trace entry (the duplication can actually be useful).