From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jaspal Subject: Re: [Qemu-devel] Memory Tracking API Date: Mon, 21 May 2012 08:58:58 +0530 Message-ID: <4FB9B67A.2020409@gmail.com> References: <4FB53E20.40600@gmail.com> <20120517184744.GA4377@amd.home.annexia.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: qemu-devel@nongnu.org, kvm@vger.kernel.org To: "Richard W.M. Jones" Return-path: Received: from mail-pz0-f46.google.com ([209.85.210.46]:33346 "EHLO mail-pz0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751728Ab2EUD3C (ORCPT ); Sun, 20 May 2012 23:29:02 -0400 Received: by dady13 with SMTP id y13so6216451dad.19 for ; Sun, 20 May 2012 20:29:02 -0700 (PDT) In-Reply-To: <20120517184744.GA4377@amd.home.annexia.org> Sender: kvm-owner@vger.kernel.org List-ID: On 05/18/2012 12:17 AM, Richard W.M. Jones wrote: > On Thu, May 17, 2012 at 11:36:24PM +0530, Jaspal wrote: >> Hi , >> >> Is it possible to keep a count of reads / writes taking place in a >> vm using qemu ( using kvm as hypervisor ) ? Is there a api ( or any >> patch ) for it ? > Memory reads and writes is surely going to generate a huge > amount of output! > > There are various DEBUG_* symbols at the top of exec.c and ioport.c. > I've only used a few of these: > > DEBUG_UNASSIGNED - prints a message when an unmapped page is > referenced (TCG only, presumably?) > > DEBUG_IOPORT - prints a message when any I/O port is referenced > > DEBUG_UNUSED_IOPORT - prints a message when a non-emulated I/O port > is referenced > > There are several more if you look at the code. > > Rich. > When are these functions called : kvm_read_guest_page , kvm_read_guest_atomic , kvm_write_guest_page present in kvm_main.c ? When qemu wants to read/write to a page ? If qemu has to read/write on the vm's memory ( RAM ) , does the process always involve kvm ? Thanks , Jaspal