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=-16.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,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 50B7AC433DB for ; Fri, 15 Jan 2021 15:38:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1B5D723888 for ; Fri, 15 Jan 2021 15:38:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726370AbhAOPib (ORCPT ); Fri, 15 Jan 2021 10:38:31 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:52654 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725910AbhAOPia (ORCPT ); Fri, 15 Jan 2021 10:38:30 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1610725023; 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=BfcFWEUkq1XDvrKtOfvXgBhHwBlztowWw4UTv6iuSJY=; b=iDUWGMJ36bFEaOZ3JD6E9wZXd/fHCTY85PGaswM2etl5f+p7ktBOOe4Gl9dw7ZttcTpcg8 fk/SZJzfPld+zFpWXJ/1yncR2q7BmUiPKLfAhhnesZ3bdCsV665Ztz878+kr/+tA95LQVf JzcUGt5IxkJQziG2DYaEF/UEKj6+nR0= 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-86-7_VsT0NsPqC4bV3TWIZRhg-1; Fri, 15 Jan 2021 10:37:02 -0500 X-MC-Unique: 7_VsT0NsPqC4bV3TWIZRhg-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id A667C80A5C0; Fri, 15 Jan 2021 15:36:59 +0000 (UTC) Received: from gondolin (ovpn-114-124.ams2.redhat.com [10.36.114.124]) by smtp.corp.redhat.com (Postfix) with ESMTP id 1405E5C3E9; Fri, 15 Jan 2021 15:36:48 +0000 (UTC) Date: Fri, 15 Jan 2021 16:36:46 +0100 From: Cornelia Huck To: David Gibson Cc: brijesh.singh@amd.com, pair@us.ibm.com, dgilbert@redhat.com, pasic@linux.ibm.com, qemu-devel@nongnu.org, Richard Henderson , Marcelo Tosatti , David Hildenbrand , borntraeger@de.ibm.com, Marcel Apfelbaum , Paolo Bonzini , mst@redhat.com, jun.nakajima@intel.com, thuth@redhat.com, pragyansri.pathi@intel.com, kvm@vger.kernel.org, Eduardo Habkost , qemu-s390x@nongnu.org, qemu-ppc@nongnu.org, frankja@linux.ibm.com, Greg Kurz , mdroth@linux.vnet.ibm.com, berrange@redhat.com, andi.kleen@intel.com Subject: Re: [PATCH v7 09/13] confidential guest support: Update documentation Message-ID: <20210115163646.2ecdc329.cohuck@redhat.com> In-Reply-To: <20210113235811.1909610-10-david@gibson.dropbear.id.au> References: <20210113235811.1909610-1-david@gibson.dropbear.id.au> <20210113235811.1909610-10-david@gibson.dropbear.id.au> Organization: Red Hat GmbH MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Thu, 14 Jan 2021 10:58:07 +1100 David Gibson wrote: > Now that we've implemented a generic machine option for configuring various > confidential guest support mechanisms: > 1. Update docs/amd-memory-encryption.txt to reference this rather than > the earlier SEV specific option > 2. Add a docs/confidential-guest-support.txt to cover the generalities of > the confidential guest support scheme > > Signed-off-by: David Gibson > --- > docs/amd-memory-encryption.txt | 2 +- > docs/confidential-guest-support.txt | 43 +++++++++++++++++++++++++++++ > 2 files changed, 44 insertions(+), 1 deletion(-) > create mode 100644 docs/confidential-guest-support.txt > > diff --git a/docs/amd-memory-encryption.txt b/docs/amd-memory-encryption.txt > index 80b8eb00e9..145896aec7 100644 > --- a/docs/amd-memory-encryption.txt > +++ b/docs/amd-memory-encryption.txt > @@ -73,7 +73,7 @@ complete flow chart. > To launch a SEV guest > > # ${QEMU} \ > - -machine ...,memory-encryption=sev0 \ > + -machine ...,confidential-guest-support=sev0 \ > -object sev-guest,id=sev0,cbitpos=47,reduced-phys-bits=1 > > Debugging > diff --git a/docs/confidential-guest-support.txt b/docs/confidential-guest-support.txt > new file mode 100644 > index 0000000000..2790425b38 > --- /dev/null > +++ b/docs/confidential-guest-support.txt Maybe make this a proper .rst from the start and hook this up into the system guide? It is already almost there. > @@ -0,0 +1,43 @@ > +Confidential Guest Support > +========================== > + > +Traditionally, hypervisors such as qemu have complete access to a s/qemu/QEMU/ ? > +guest's memory and other state, meaning that a compromised hypervisor > +can compromise any of its guests. A number of platforms have added > +mechanisms in hardware and/or firmware which give guests at least some > +protection from a compromised hypervisor. This is obviously > +especially desirable for public cloud environments. > + > +These mechanisms have different names and different modes of > +operation, but are often referred to as Secure Guests or Confidential > +Guests. We use the term "Confidential Guest Support" to distinguish > +this from other aspects of guest security (such as security against > +attacks from other guests, or from network sources). > + > +Running a Confidential Guest > +---------------------------- > + > +To run a confidential guest you need to add two command line parameters: > + > +1. Use "-object" to create a "confidential guest support" object. The > + type and parameters will vary with the specific mechanism to be > + used > +2. Set the "confidential-guest-support" machine parameter to the ID of > + the object from (1). > + > +Example (for AMD SEV):: > + > + qemu-system-x86_64 \ > + \ > + -machine ...,confidential-guest-support=sev0 \ > + -object sev-guest,id=sev0,cbitpos=47,reduced-phys-bits=1 > + > +Supported mechanisms > +-------------------- > + > +Currently supported confidential guest mechanisms are: > + > +AMD Secure Encrypted Virtualization (SEV) > + docs/amd-memory-encryption.txt > + > +Other mechanisms may be supported in future. LGTM.