From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:55232) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Sz0rC-0007Rl-KW for qemu-devel@nongnu.org; Wed, 08 Aug 2012 03:39:07 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Sz0rB-0006nh-Ge for qemu-devel@nongnu.org; Wed, 08 Aug 2012 03:39:06 -0400 Received: from csmailer.cs.nctu.edu.tw ([140.113.235.130]:45759) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Sz0rB-0006n9-0J for qemu-devel@nongnu.org; Wed, 08 Aug 2012 03:39:05 -0400 Received: from csmailer.cs.nctu.edu.tw (localhost [127.0.0.1]) by csmailer.cs.nctu.edu.tw (Postfix) with ESMTP id 5143FE51 for ; Wed, 8 Aug 2012 15:38:57 +0800 (CST) Received: from alumni.cs.nctu.edu.tw (alumni.cs.nctu.edu.tw [140.113.235.116]) by csmailer.cs.nctu.edu.tw (Postfix) with ESMTP id 3CE58E50 for ; Wed, 8 Aug 2012 15:38:57 +0800 (CST) Received: (from chenwj@localhost) by alumni.cs.nctu.edu.tw (8.14.4/8.14.4/Submit) id q787cunD086215 for qemu-devel@nongnu.org; Wed, 8 Aug 2012 15:38:56 +0800 (CST) (envelope-from chenwj) Date: Wed, 8 Aug 2012 15:38:56 +0800 From: =?utf-8?B?6Zmz6Z+L5Lu7IChXZWktUmVuIENoZW4p?= Message-ID: <20120808073856.GA84469@cs.nctu.edu.tw> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Subject: [Qemu-devel] Is it possible to detect guest OS modifying pte inside QEMU? List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Hi all, Just for research, we are studying if we can leave the guest page table walk to underlying hardware rather than using software emulation (like current approach). So, maybe (if *doable*) we can use x86 hardware to help us to walk guest (like ARM) page table. The rough idea is we have to maintain a x86-format shadow page table for the corresponding ARM page table, point host cr3 to the shadow page table, and let x86 hardware do its job. The problem is, we have to aware that guest is modifying its guest page table entry so that we can sync its corrsponding shadow page table. But, we still haven't find a good way to know when the guest OS is modifying guest page table entry. Any idea is welcomed. Thanks. Regards, chenwj --=20 Wei-Ren Chen (=E9=99=B3=E9=9F=8B=E4=BB=BB) Computer Systems Lab, Institute of Information Science, Academia Sinica, Taiwan (R.O.C.) Tel:886-2-2788-3799 #1667 Homepage: http://people.cs.nctu.edu.tw/~chenwj