From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E6E40C0044D for ; Mon, 16 Mar 2020 03:18:09 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id ABFDC20679 for ; Mon, 16 Mar 2020 03:18:09 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=gibson.dropbear.id.au header.i=@gibson.dropbear.id.au header.b="IcJzuZbQ" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org ABFDC20679 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=gibson.dropbear.id.au Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:33634 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jDgGW-0002Vx-Ja for qemu-devel@archiver.kernel.org; Sun, 15 Mar 2020 23:18:08 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:37281) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jDgAp-00011L-32 for qemu-devel@nongnu.org; Sun, 15 Mar 2020 23:12:16 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1jDgAm-0007NR-MW for qemu-devel@nongnu.org; Sun, 15 Mar 2020 23:12:14 -0400 Received: from ozlabs.org ([203.11.71.1]:34995) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1jDgAm-0007BP-85; Sun, 15 Mar 2020 23:12:12 -0400 Received: by ozlabs.org (Postfix, from userid 1007) id 48ghDS5ph4z9sP7; Mon, 16 Mar 2020 14:12:08 +1100 (AEDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gibson.dropbear.id.au; s=201602; t=1584328328; bh=rWp0kCwF/mgRUOryiJHj0URSWLD+4CW9MiMnqlu1W/M=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=IcJzuZbQGDu+xHnj177JQXN+YCrttZOahUSfAOUrLo4Ii8rt7gtAEQQEL58Rr3Pgt aV7Whp5prgeX347XieICvB91GLDFhfRggla6t09IQLnncpsH96FBJ2KAAq6w4LHs2l B43PjAFLwlh4OnWvtM8+wrHSoTEgEhEoysvMi7gQ= Date: Mon, 16 Mar 2020 14:06:46 +1100 From: David Gibson To: "Michael S. Tsirkin" Subject: Re: Upstream QEMU guest support policy ? Re: [PATCH v3 0/2] spapr: Use vIOMMU translation for virtio by default Message-ID: <20200316030646.GH2013@umbus.fritz.box> References: <20200305043009.611636-1-david@gibson.dropbear.id.au> <20200310114343.GD3234052@redhat.com> <20200311011247.GT660117@umbus.fritz.box> <20200311031202-mutt-send-email-mst@kernel.org> <20200312011049.GC711223@umbus.fritz.box> <20200312023041-mutt-send-email-mst@kernel.org> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="dDnEQgWzhgf+8aPe" Content-Disposition: inline In-Reply-To: <20200312023041-mutt-send-email-mst@kernel.org> X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 203.11.71.1 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: pair@us.ibm.com, Daniel =?iso-8859-1?Q?P=2E_Berrang=E9?= , aik@ozlabs.ru, groug@kaod.org, qemu-devel@nongnu.org, paulus@samba.org, clg@kaod.org, mdroth@us.ibm.com, qemu-ppc@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" --dDnEQgWzhgf+8aPe Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Mar 12, 2020 at 02:32:11AM -0400, Michael S. Tsirkin wrote: > On Thu, Mar 12, 2020 at 12:10:49PM +1100, David Gibson wrote: > > On Wed, Mar 11, 2020 at 03:33:59AM -0400, Michael S. Tsirkin wrote: > > > On Wed, Mar 11, 2020 at 12:12:47PM +1100, David Gibson wrote: > > > > I am wondering if we have to introduce an "svm=3Don" flag anyway. = It's > > > > pretty ugly, since all it would be doing is changing defaults here = and > > > > there for compatibilty with a possible future SVM transition, but > > > > maybe it's the best we can do :/. > > >=20 > > > Frankly I'm surprised there's no way for the hypervisor to block VM > > > transition to secure mode. To me an inability to disable DRM looks li= ke > > > a security problem. > >=20 > > Uh.. I don't immediately see how it's a security problem, though I'm > > certainly convinced it's a problem in other ways. >=20 > Well for one it breaks introspection, allowing guests to hide > malicious code from hypervisors. Hm, ok. Is that much used in practice? (Aside: I don't think I'd call that "introspection" since it's one thing examining another, not something examining itself). >=20 > > > Does not the ultravisor somehow allow > > > enabling/disabling this functionality from the hypervisor? > >=20 > > Not at present, but as mentioned on the other thread, Paul and I came > > up with a tentative plan to change that. > >=20 > > > It would be > > > even better if the hypervisor could block the guest from poking at the > > > ultravisor completely but I guess that would be too much to hope for. > >=20 > > Yeah, probably :/. > >=20 >=20 >=20 --=20 David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson --dDnEQgWzhgf+8aPe Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEEdfRlhq5hpmzETofcbDjKyiDZs5IFAl5u7UUACgkQbDjKyiDZ s5K4lhAAsH+/+1eM/obXI6wAXaRv9WUWALHMVNzFxhHcBHdVZmgKObIS9Xduvsmn UypNqeaAehJZsyaI8bjUMCG0cHgEljpOpPx4Rujm9CwXBxiiJW6LbqoWjsxJLbX6 OHdfa+cWZ9fM6t/GHPoxC7OFA/UGxqzRC4zy2ScrjN4ncTLS5Uo7JRAhwfyej2S7 d+oYhMbEUkAdKUXAT/a6l+Se2/5L3N5icT3c0VR5BWMj9Dx0pb598WlWt24GAS6I vOS1Y/i36xbWUsfLeNyWlAuBRUfjH12Hp/yVujCI3P4Wm1JodakdVhAkJKYvM8Bu Txsun3QW/bH2R9HX8HDmzbKKuI85YYA84RiyUg9Y/S9nqTF3tQaMIkW1DxuOgI9j 9eR7xbaagJ8oMMJEkyaOdLNLPfX7LF1qx6ahYKi0O3kWe1hzFXrv1gIyhEHhpI60 UB+2DXD26tekTDxs6sv3jVz3tPyIhvDRNC5WP44sSDnvfVj6Lb87tgcZoKYuix3V 8LLuFjiBd8AvCcZVnjVdBTjtZgdbFl/qzBHXsvhmAbYTttLGNYt48yO6NIgq+ere O4pduUuHXjqR/OtS3uyd3AD3wdKh2kz5uRClqNW+96h9GL+Yl6giBG9IO33RvhkF mJxMzFKVGq/PesB77FAxOL9JJrmnfkO+rYSoD+Osi34lw6gO0Vo= =Nalz -----END PGP SIGNATURE----- --dDnEQgWzhgf+8aPe--