From patchwork Mon Feb 8 06:05:34 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Gibson X-Patchwork-Id: 12073973 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=-18.8 required=3.0 tests=BAYES_00,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, USER_AGENT_GIT autolearn=ham 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 761F4C433DB for ; Mon, 8 Feb 2021 06:06:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3ED4664E27 for ; Mon, 8 Feb 2021 06:06:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229727AbhBHGGq (ORCPT ); Mon, 8 Feb 2021 01:06:46 -0500 Received: from ozlabs.org ([203.11.71.1]:47473 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229698AbhBHGGd (ORCPT ); Mon, 8 Feb 2021 01:06:33 -0500 Received: by ozlabs.org (Postfix, from userid 1007) id 4DYwVt0gk7z9sWH; Mon, 8 Feb 2021 17:05:41 +1100 (AEDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gibson.dropbear.id.au; s=201602; t=1612764342; bh=EX4Wo8XL9ghYEf3SyZWEad+uxvbQlvG/RZ3Zj48wzzQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=TwjqbefQmNWML/ImcTbkH1rIKtOcSXXRm7iAyTUFW1nG2sNQCsLEjxrMCUQfENFDJ msRcSNrb3JyCsFor9P38i/qHvdzT2VfIXMLMpnh9JiL5W34a5FPRjkiVJ3wJlPbq2g 2/HZJipqr2hYL/ekWbTwhmDGb+pCHVqW7nQS5ZLo= From: David Gibson To: pasic@linux.ibm.com, dgilbert@redhat.com, pair@us.ibm.com, qemu-devel@nongnu.org, brijesh.singh@amd.com Cc: ehabkost@redhat.com, mtosatti@redhat.com, mst@redhat.com, jun.nakajima@intel.com, kvm@vger.kernel.org, Richard Henderson , qemu-s390x@nongnu.org, Marcel Apfelbaum , pbonzini@redhat.com, frankja@linux.ibm.com, andi.kleen@intel.com, cohuck@redhat.com, Thomas Huth , borntraeger@de.ibm.com, mdroth@linux.vnet.ibm.com, David Gibson , =?utf-8?q?Daniel_P=2E_Berrang=C3=A9?= , qemu-ppc@nongnu.org, David Hildenbrand , Greg Kurz , pragyansri.pathi@intel.com Subject: [PULL v9 09/13] confidential guest support: Update documentation Date: Mon, 8 Feb 2021 17:05:34 +1100 Message-Id: <20210208060538.39276-10-david@gibson.dropbear.id.au> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210208060538.39276-1-david@gibson.dropbear.id.au> References: <20210208060538.39276-1-david@gibson.dropbear.id.au> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org 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 Reviewed-by: Greg Kurz --- 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..bd439ac800 --- /dev/null +++ b/docs/confidential-guest-support.txt @@ -0,0 +1,43 @@ +Confidential Guest Support +========================== + +Traditionally, hypervisors such as QEMU have complete access to a +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.