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=-13.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 D402BC433DB for ; Mon, 18 Jan 2021 03:06:51 +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 2DF6C223DB for ; Mon, 18 Jan 2021 03:06:50 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2DF6C223DB 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]:44504 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1l1KsU-00009F-3a for qemu-devel@archiver.kernel.org; Sun, 17 Jan 2021 22:06:50 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:50218) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1l1KqS-0007fR-3x; Sun, 17 Jan 2021 22:04:44 -0500 Received: from bilbo.ozlabs.org ([2401:3900:2:1::2]:45513 helo=ozlabs.org) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1l1KqO-0002Om-KY; Sun, 17 Jan 2021 22:04:43 -0500 Received: by ozlabs.org (Postfix, from userid 1007) id 4DJxTZ1PcDz9sW8; Mon, 18 Jan 2021 14:04:34 +1100 (AEDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gibson.dropbear.id.au; s=201602; t=1610939074; bh=IY+EtdUcdbw4Y7gyTL/tzbEUdbfdDC6K5ehntJd5eb4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=dSlE3HKvknUv+8MfV/Pqiy4MaPK4emj2IILCD3Q1SX5VkQ8MOJlPY6Jr4tqsGsqpK tl/JT9eHq4ZTa/Oi+ygCA0pmx4ypgDtKLlcJU0KI6xGlr0smEYVlRnHgU72iR5UPmR N7nHmVxwOuO3s8KgJ/INPRCOFZqHMZGjbqERZub4= Date: Mon, 18 Jan 2021 13:59:15 +1100 From: David Gibson To: Cornelia Huck Subject: Re: [PATCH v7 03/13] sev: Remove false abstraction of flash encryption Message-ID: <20210118025915.GF2089552@yekko.fritz.box> References: <20210113235811.1909610-1-david@gibson.dropbear.id.au> <20210113235811.1909610-4-david@gibson.dropbear.id.au> <20210115135425.7fd94aed.cohuck@redhat.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="1Ow488MNN9B9o/ov" Content-Disposition: inline In-Reply-To: <20210115135425.7fd94aed.cohuck@redhat.com> Received-SPF: pass client-ip=2401:3900:2:1::2; envelope-from=dgibson@ozlabs.org; helo=ozlabs.org X-Spam_score_int: -17 X-Spam_score: -1.8 X-Spam_bar: - X-Spam_report: (-1.8 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, HEADER_FROM_DIFFERENT_DOMAINS=0.25, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=no autolearn_force=no X-Spam_action: no action 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, brijesh.singh@amd.com, kvm@vger.kernel.org, David Hildenbrand , qemu-devel@nongnu.org, frankja@linux.ibm.com, pragyansri.pathi@intel.com, mst@redhat.com, mdroth@linux.vnet.ibm.com, pasic@linux.ibm.com, borntraeger@de.ibm.com, andi.kleen@intel.com, thuth@redhat.com, Eduardo Habkost , Richard Henderson , dgilbert@redhat.com, Greg Kurz , qemu-s390x@nongnu.org, jun.nakajima@intel.com, berrange@redhat.com, Marcelo Tosatti , qemu-ppc@nongnu.org, Paolo Bonzini Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" --1Ow488MNN9B9o/ov Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Jan 15, 2021 at 01:54:25PM +0100, Cornelia Huck wrote: > On Thu, 14 Jan 2021 10:58:01 +1100 > David Gibson wrote: >=20 > > When AMD's SEV memory encryption is in use, flash memory banks (which a= re > > initialed by pc_system_flash_map()) need to be encrypted with the guest= 's > > key, so that the guest can read them. > >=20 > > That's abstracted via the kvm_memcrypt_encrypt_data() callback in the K= VM > > state.. except, that it doesn't really abstract much at all. > >=20 > > For starters, the only called is in code specific to the 'pc' family of >=20 > s/called/call site/ Fixed, thanks. >=20 > > machine types, so it's obviously specific to those and to x86 to begin > > with. But it makes a bunch of further assumptions that need not be true > > about an arbitrary confidential guest system based on memory encryption, > > let alone one based on other mechanisms: > >=20 > > * it assumes that the flash memory is defined to be encrypted with the > > guest key, rather than being shared with hypervisor > > * it assumes that that hypervisor has some mechanism to encrypt data i= nto > > the guest, even though it can't decrypt it out, since that's the who= le > > point > > * the interface assumes that this encrypt can be done in place, which > > implies that the hypervisor can write into a confidential guests's > > memory, even if what it writes isn't meaningful > >=20 > > So really, this "abstraction" is actually pretty specific to the way SEV > > works. So, this patch removes it and instead has the PC flash > > initialization code call into a SEV specific callback. > >=20 > > Signed-off-by: David Gibson > > --- > > accel/kvm/kvm-all.c | 31 ++----------------------------- > > accel/kvm/sev-stub.c | 9 ++------- > > accel/stubs/kvm-stub.c | 10 ---------- > > hw/i386/pc_sysfw.c | 17 ++++++----------- > > include/sysemu/kvm.h | 16 ---------------- > > include/sysemu/sev.h | 4 ++-- > > target/i386/sev-stub.c | 5 +++++ > > target/i386/sev.c | 24 ++++++++++++++---------- > > 8 files changed, 31 insertions(+), 85 deletions(-) >=20 > Reviewed-by: Cornelia Huck >=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 --1Ow488MNN9B9o/ov Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEEdfRlhq5hpmzETofcbDjKyiDZs5IFAmAE+YEACgkQbDjKyiDZ s5JqpxAA2JPKpVmOQc2xg4NC6iOvJisQ7ELyJmraenLUuf6UyaxJFrdMsuWAxQkF UNYhYqeFWv+d3wcC1Y98Yudqd7A+hlOrKkybwByD9XPr0iBTEFOXKvA1kVusYkPR 2QBL9YOPpiLoteG4kDIJXlCzL6AItS2N1PN4mraBE25JHLkvcedbQtzZkslB/+aF 8vJFpTkRCUnKvyROVC9uDU5bFlbYKX55seDZ2xDj2ezM1oPCVCdC0exMcUoIsBs2 Tw9BzNvavrwsBFaa2c8aG1uDGlJuo+O7wFbZg1SPx+p2apq0BYm74i7dY/5y62ne jU4xu3+pA53HlDM4KfH8xSyDTYkHSQ+gbTzxIvxjwu/vkkoN+fBGBrO7VrsVN+z+ 0GmW/xG6MdDps9fkvzhB5anc6MgZOaFGqWhCb6sxovf+EsvJ5IhG5k8n9C8Ap+r9 EYEbNzDxCO29UqzuYlGGUnsnRGdIjH6Ti5BnVH35wAteZCs9GA91nHEDT23gqoMV h6fbISfoT3yloLjQBP6bD+uIn79nD8V7uOuIxM4JyAuVScuWE7W6ojvq7KoQy9Wv tFKPeNH8dzR65AjvvONLJ261M6JxYsOJZtTX0tL92gFTYyQUD81SYFF2ZDGktFJw InUJptHHR1SxryMAc+4eiuwjePiPUXOdCb2uFkSR9vF+Jd3uBRg= =PCsc -----END PGP SIGNATURE----- --1Ow488MNN9B9o/ov--