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=-13.6 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 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 7007FC433B4 for ; Mon, 26 Apr 2021 12:14:46 +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 D2A4F610A2 for ; Mon, 26 Apr 2021 12:14:45 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D2A4F610A2 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:59146 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lb08S-0006s6-I2 for qemu-devel@archiver.kernel.org; Mon, 26 Apr 2021 08:14:44 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:45042) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lb05e-0005Xp-Sn for qemu-devel@nongnu.org; Mon, 26 Apr 2021 08:11:50 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:32766) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lb05W-0004GK-Tu for qemu-devel@nongnu.org; Mon, 26 Apr 2021 08:11:46 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1619439101; 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=aTVjsEI7DFYcH8nDEpmRKpivu81F2ommPNOO1J3153I=; b=WW0cR6XrmsIklipFDeeoe6O+ssRDomgKhuZ+HwpJSfdx2x+gZan9ju+pbxE4dYQ+tx7r50 nB3GOuIpUKpM24PhG47jqfy/85mAdctkdRZ6vGyjP9xlDWtOaF4zieHViCae3BBGE8B+IG bIZNM8XrDPMNQUTLb2EF9PXUFn9xyu0= 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-238-Q18ctlhaNPK76f_egtiTQQ-1; Mon, 26 Apr 2021 08:11:39 -0400 X-MC-Unique: Q18ctlhaNPK76f_egtiTQQ-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 739B2107ACC7; Mon, 26 Apr 2021 12:11:38 +0000 (UTC) Received: from lacos-laptop-7.usersys.redhat.com (ovpn-115-153.ams2.redhat.com [10.36.115.153]) by smtp.corp.redhat.com (Postfix) with ESMTP id 3D58B10074F1; Mon, 26 Apr 2021 12:11:36 +0000 (UTC) Subject: Re: [PATCH v2 1/3] doc: Fix some mistakes in the SEV documentation To: Tom Lendacky , qemu-devel@nongnu.org References: From: Laszlo Ersek Message-ID: <78472e17-2efe-c06f-09aa-5f2da2381657@redhat.com> Date: Mon, 26 Apr 2021 14:11:35 +0200 MIME-Version: 1.0 In-Reply-To: X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=lersek@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=170.10.133.124; envelope-from=lersek@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -29 X-Spam_score: -3.0 X-Spam_bar: --- X-Spam_report: (-3.0 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.219, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham 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: Pavel Hrdina , "Daniel P . Berrange" , Eduardo Habkost , Michal Privoznik , "Dr. David Alan Gilbert" , Brijesh Singh , Paolo Bonzini Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 04/23/21 22:08, Tom Lendacky wrote: > From: Tom Lendacky > > Fix some spelling and grammar mistakes in the amd-memory-encryption.txt > file. No new information added. > > Signed-off-by: Tom Lendacky > --- > docs/amd-memory-encryption.txt | 59 +++++++++++++++++----------------- > 1 file changed, 29 insertions(+), 30 deletions(-) > > diff --git a/docs/amd-memory-encryption.txt b/docs/amd-memory-encryption.txt > index 145896aec7..ed85159ea7 100644 > --- a/docs/amd-memory-encryption.txt > +++ b/docs/amd-memory-encryption.txt > @@ -1,38 +1,38 @@ > Secure Encrypted Virtualization (SEV) is a feature found on AMD processors. > > SEV is an extension to the AMD-V architecture which supports running encrypted > -virtual machine (VMs) under the control of KVM. Encrypted VMs have their pages > +virtual machines (VMs) under the control of KVM. Encrypted VMs have their pages > (code and data) secured such that only the guest itself has access to the > unencrypted version. Each encrypted VM is associated with a unique encryption > -key; if its data is accessed to a different entity using a different key the > +key; if its data is accessed by a different entity using a different key the > encrypted guests data will be incorrectly decrypted, leading to unintelligible > data. > > -The key management of this feature is handled by separate processor known as > -AMD secure processor (AMD-SP) which is present in AMD SOCs. Firmware running > -inside the AMD-SP provide commands to support common VM lifecycle. This > +Key management for this feature is handled by a separate processor known as the > +AMD secure processor (AMD-SP), which is present in AMD SOCs. Firmware running > +inside the AMD-SP provides commands to support a common VM lifecycle. This > includes commands for launching, snapshotting, migrating and debugging the > -encrypted guest. Those SEV command can be issued via KVM_MEMORY_ENCRYPT_OP > +encrypted guest. These SEV commands can be issued via KVM_MEMORY_ENCRYPT_OP > ioctls. > > Launching > --------- > -Boot images (such as bios) must be encrypted before guest can be booted. > -MEMORY_ENCRYPT_OP ioctl provides commands to encrypt the images :LAUNCH_START, > +Boot images (such as bios) must be encrypted before a guest can be booted. The > +MEMORY_ENCRYPT_OP ioctl provides commands to encrypt the images: LAUNCH_START, > LAUNCH_UPDATE_DATA, LAUNCH_MEASURE and LAUNCH_FINISH. These four commands > together generate a fresh memory encryption key for the VM, encrypt the boot > -images and provide a measurement than can be used as an attestation of the > +images and provide a measurement than can be used as an attestation of a > successful launch. > > LAUNCH_START is called first to create a cryptographic launch context within > -the firmware. To create this context, guest owner must provides guest policy, > +the firmware. To create this context, guest owner must provide a guest policy, > its public Diffie-Hellman key (PDH) and session parameters. These inputs > -should be treated as binary blob and must be passed as-is to the SEV firmware. > +should be treated as a binary blob and must be passed as-is to the SEV firmware. > > -The guest policy is passed as plaintext and hypervisor may able to read it > +The guest policy is passed as plaintext. A hypervisor may choose to read it, > but should not modify it (any modification of the policy bits will result > in bad measurement). The guest policy is a 4-byte data structure containing > -several flags that restricts what can be done on running SEV guest. > +several flags that restricts what can be done on a running SEV guest. > See KM Spec section 3 and 6.2 for more details. > > The guest policy can be provided via the 'policy' property (see below) > @@ -40,31 +40,30 @@ The guest policy can be provided via the 'policy' property (see below) > # ${QEMU} \ > sev-guest,id=sev0,policy=0x1...\ > > -Guest owners provided DH certificate and session parameters will be used to > +The guest owner provided DH certificate and session parameters will be used to > establish a cryptographic session with the guest owner to negotiate keys used > for the attestation. > > -The DH certificate and session blob can be provided via 'dh-cert-file' and > -'session-file' property (see below > +The DH certificate and session blob can be provided via the 'dh-cert-file' and > +'session-file' properties (see below) > > # ${QEMU} \ > sev-guest,id=sev0,dh-cert-file=,session-file= > > LAUNCH_UPDATE_DATA encrypts the memory region using the cryptographic context > -created via LAUNCH_START command. If required, this command can be called > +created via the LAUNCH_START command. If required, this command can be called > multiple times to encrypt different memory regions. The command also calculates > the measurement of the memory contents as it encrypts. > > -LAUNCH_MEASURE command can be used to retrieve the measurement of encrypted > -memory. This measurement is a signature of the memory contents that can be > -sent to the guest owner as an attestation that the memory was encrypted > -correctly by the firmware. The guest owner may wait to provide the guest > -confidential information until it can verify the attestation measurement. > -Since the guest owner knows the initial contents of the guest at boot, the > -attestation measurement can be verified by comparing it to what the guest owner > -expects. > +LAUNCH_MEASURE can be used to retrieve the measurement of encrypted memory. > +This measurement is a signature of the memory contents that can be sent to the > +guest owner as an attestation that the memory was encrypted correctly by the > +firmware. The guest owner may wait to provide the guest confidential information > +until it can verify the attestation measurement. Since the guest owner knows the > +initial contents of the guest at boot, the attestation measurement can be > +verified by comparing it to what the guest owner expects. > > -LAUNCH_FINISH command finalizes the guest launch and destroy's the cryptographic > +LAUNCH_FINISH finalizes the guest launch and destroys the cryptographic > context. > > See SEV KM API Spec [1] 'Launching a guest' usage flow (Appendix A) for the > @@ -78,10 +77,10 @@ To launch a SEV guest > > Debugging > ----------- > -Since memory contents of SEV guest is encrypted hence hypervisor access to the > -guest memory will get a cipher text. If guest policy allows debugging, then > -hypervisor can use DEBUG_DECRYPT and DEBUG_ENCRYPT commands access the guest > -memory region for debug purposes. This is not supported in QEMU yet. > +Since the memory contents of a SEV guest are encrypted, hypervisor access to > +the guest memory will return cipher text. If the guest policy allows debugging, > +then a hypervisor can use the DEBUG_DECRYPT and DEBUG_ENCRYPT commands to access > +the guest memory region for debug purposes. This is not supported in QEMU yet. > > Snapshot/Restore > ----------------- > Reviewed-by: Laszlo Ersek