From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:54393) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bjdSi-0008By-EY for qemu-devel@nongnu.org; Mon, 12 Sep 2016 22:28:41 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bjdSc-0002f2-Dt for qemu-devel@nongnu.org; Mon, 12 Sep 2016 22:28:39 -0400 Received: from mx1.redhat.com ([209.132.183.28]:35176) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bjdSc-0002dy-8Q for qemu-devel@nongnu.org; Mon, 12 Sep 2016 22:28:34 -0400 Date: Tue, 13 Sep 2016 10:28:27 +0800 From: Fam Zheng Message-ID: <20160913022827.GD15800@lemon> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Subject: Re: [Qemu-devel] (no subject) List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Stephen Bates Cc: qemu-devel@nongnu.org On Mon, 09/12 16:23, Stephen Bates wrote: > Hi Hi Stephen, > > I sent this to qemu-discuss with no success so resending to qemu-devel. > > I am doing some very low level OS design work and wanted to be able to > alter some values in the physical memory of my QEMU guest. I can see quite > a few ways to print/dump both physical and virtual addresses but nothing > that can alter arbitrary physical/virtual addresses? > > Does such a feature exist in Qemu and if it does are there pointers to > documentation for it? Have you tried the builtin gdbstub in QEMU? You can add "-s" to the QEMU command line and then connect to it from gdb with "target remote :1234". There you can inspect or change memory more easily. Fam > > I do see that we can use file backing for very large memory regions via > the memory-backing-file option but I am not really trying to alter massive > regions of memory in this case. > > Cheers > > Stephen Bates >