From patchwork Tue Jan 12 04:45:04 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Gibson X-Patchwork-Id: 12012375 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 87EC8C433E0 for ; Tue, 12 Jan 2021 04:46:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 542F0221FE for ; Tue, 12 Jan 2021 04:46:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732238AbhALEqB (ORCPT ); Mon, 11 Jan 2021 23:46:01 -0500 Received: from bilbo.ozlabs.org ([203.11.71.1]:54409 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732097AbhALEqA (ORCPT ); Mon, 11 Jan 2021 23:46:00 -0500 Received: by ozlabs.org (Postfix, from userid 1007) id 4DFJ0S1qsDz9t15; Tue, 12 Jan 2021 15:45:12 +1100 (AEDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gibson.dropbear.id.au; s=201602; t=1610426712; bh=XAe7Xx+YpNUPHcyhxW/cHKgMuEbgQoNbc1c/1ol/ah8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=gsgUbwoe/uiSnZj4VGfKpGe5Ib+aKheRMxqeX9Ln6sYcVvmJg1D53AAky24w2MF96 VvM0yqUgiQzuZbqTtB08ba0jsQBdyg8VlrWvHr6WVAKfeNyns5k4kRX/oyZwG5X4Ox QE3wVg4PCZ3eUco9uBmCLYgUm08Epv/kF+W/HQTA= From: David Gibson To: pasic@linux.ibm.com, brijesh.singh@amd.com, pair@us.ibm.com, dgilbert@redhat.com, qemu-devel@nongnu.org Cc: andi.kleen@intel.com, qemu-ppc@nongnu.org, Paolo Bonzini , Marcelo Tosatti , David Gibson , Greg Kurz , frankja@linux.ibm.com, thuth@redhat.com, Christian Borntraeger , mdroth@linux.vnet.ibm.com, richard.henderson@linaro.org, kvm@vger.kernel.org, =?utf-8?q?Daniel_P=2E_Be?= =?utf-8?q?rrang=C3=A9?= , Marcel Apfelbaum , Eduardo Habkost , david@redhat.com, Cornelia Huck , mst@redhat.com, qemu-s390x@nongnu.org, pragyansri.pathi@intel.com, jun.nakajima@intel.com Subject: [PATCH v6 09/13] confidential guest support: Update documentation Date: Tue, 12 Jan 2021 15:45:04 +1100 Message-Id: <20210112044508.427338-10-david@gibson.dropbear.id.au> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210112044508.427338-1-david@gibson.dropbear.id.au> References: <20210112044508.427338-1-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 --- 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 @@ -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.