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=-1.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 38E8DC433DF for ; Wed, 24 Jun 2020 07:07:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 051CC20823 for ; Wed, 24 Jun 2020 07:07:11 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="K22e0jNM" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389430AbgFXHHJ (ORCPT ); Wed, 24 Jun 2020 03:07:09 -0400 Received: from us-smtp-2.mimecast.com ([207.211.31.81]:45342 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S2389349AbgFXHHJ (ORCPT ); Wed, 24 Jun 2020 03:07:09 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1592982428; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Vuoo9Wk/qRlj5IesQ7i9MM7vgq2ZkA6l9+chYSUsDoU=; b=K22e0jNMwAdaBbY4YokC3eZShbX1md+RaPddvYPBfP7BjRTQHlW0FYGnRvUkOe3LwDiqlD ZXRnE2dt9znyywCQMkakkZWiGJv60FuRiEjlfi2m9o04+QsRVG3dh7iKMGgS8U9Xi5hg2y gEHXwydKPLu+i9UCEzAdDbiW4e4AUUg= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-289-ZV4iU5pCMhaB_Q7W4Oka8w-1; Wed, 24 Jun 2020 03:07:04 -0400 X-MC-Unique: ZV4iU5pCMhaB_Q7W4Oka8w-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 96B22800C60; Wed, 24 Jun 2020 07:07:01 +0000 (UTC) Received: from gondolin (ovpn-113-3.ams2.redhat.com [10.36.113.3]) by smtp.corp.redhat.com (Postfix) with ESMTP id 1654A100238C; Wed, 24 Jun 2020 07:06:50 +0000 (UTC) Date: Wed, 24 Jun 2020 09:06:48 +0200 From: Cornelia Huck To: Christian Borntraeger Cc: David Gibson , qemu-devel@nongnu.org, brijesh.singh@amd.com, pair@us.ibm.com, pbonzini@redhat.com, dgilbert@redhat.com, frankja@linux.ibm.com, Eduardo Habkost , kvm@vger.kernel.org, mst@redhat.com, david@redhat.com, mdroth@linux.vnet.ibm.com, pasic@linux.ibm.com, qemu-s390x@nongnu.org, qemu-ppc@nongnu.org, Marcel Apfelbaum , Richard Henderson Subject: Re: [PATCH v3 0/9] Generalize memory encryption models Message-ID: <20200624090648.6bdf82bd.cohuck@redhat.com> In-Reply-To: <2fa7c84a-6929-ef04-1d61-f76a4cac35f5@de.ibm.com> References: <20200619020602.118306-1-david@gibson.dropbear.id.au> <2fa7c84a-6929-ef04-1d61-f76a4cac35f5@de.ibm.com> Organization: Red Hat GmbH MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Mon, 22 Jun 2020 16:27:28 +0200 Christian Borntraeger wrote: > On 19.06.20 04:05, David Gibson wrote: > > A number of hardware platforms are implementing mechanisms whereby the > > hypervisor does not have unfettered access to guest memory, in order > > to mitigate the security impact of a compromised hypervisor. > > > > AMD's SEV implements this with in-cpu memory encryption, and Intel has > > its own memory encryption mechanism. POWER has an upcoming mechanism > > to accomplish this in a different way, using a new memory protection > > level plus a small trusted ultravisor. s390 also has a protected > > execution environment. > > > > The current code (committed or draft) for these features has each > > platform's version configured entirely differently. That doesn't seem > > ideal for users, or particularly for management layers. > > > > AMD SEV introduces a notionally generic machine option > > "machine-encryption", but it doesn't actually cover any cases other > > than SEV. > > > > This series is a proposal to at least partially unify configuration > > for these mechanisms, by renaming and generalizing AMD's > > "memory-encryption" property. It is replaced by a > > "host-trust-limitation" property pointing to a platform specific > > object which configures and manages the specific details. > > > > For now this series covers just AMD SEV and POWER PEF. I'm hoping it > > can be extended to cover the Intel and s390 mechanisms as well, > > though. > > Let me try to summarize what I understand what you try to achieve: > one command line parameter for all platforms that > > common across all platforms: > - disable KSM > - by default enables iommu_platform > > > per platform: > - setup the necessary encryption scheme when appropriate > - block migration > -.... > > > The tricky part is certainly the per platform thing. For example on > s390 we just have a cpumodel flag that provides interfaces to the guest > to switch into protected mode via the ultravisor. This works perfectly > fine with the host model, so no need to configure anything. The platform > code then disables KSM _on_switchover_ and not in general. Because the > guest CAN switch into protected, but it does not have to. > > So this feels really hard to do right. Would a virtual BoF on KVM forum > be too late? We had a BoF on protected guests last year and that was > valuable. Maybe we can do some kind of call to discuss this earlier? (Maybe in the KVM call slot on Tuesdays?) I think it would be really helpful if everybody would have at least a general understanding about how encryption/protection works on the different architectures.