From patchwork Wed Feb 26 12:20:38 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Janosch Frank X-Patchwork-Id: 11406417 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 9CF32159A for ; Wed, 26 Feb 2020 12:30:43 +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 7D55520838 for ; Wed, 26 Feb 2020 12:30:43 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7D55520838 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.ibm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Received: from localhost ([::1]:43636 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1j6vpq-00035O-Mo for patchwork-qemu-devel@patchwork.kernel.org; Wed, 26 Feb 2020 07:30:42 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:54057) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1j6vh1-00040q-UY for qemu-devel@nongnu.org; Wed, 26 Feb 2020 07:21:37 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1j6vh0-0001Yz-NI for qemu-devel@nongnu.org; Wed, 26 Feb 2020 07:21:35 -0500 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:49006) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1j6vh0-0000ix-F2 for qemu-devel@nongnu.org; Wed, 26 Feb 2020 07:21:34 -0500 Received: from pps.filterd (m0098410.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 01QCKt6n139085 for ; Wed, 26 Feb 2020 07:21:23 -0500 Received: from e06smtp07.uk.ibm.com (e06smtp07.uk.ibm.com [195.75.94.103]) by mx0a-001b2d01.pphosted.com with ESMTP id 2ydq6guhrh-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Wed, 26 Feb 2020 07:21:22 -0500 Received: from localhost by e06smtp07.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Wed, 26 Feb 2020 12:21:03 -0000 Received: from d06av25.portsmouth.uk.ibm.com (d06av25.portsmouth.uk.ibm.com [9.149.105.61]) by b06cxnps3074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 01QCL2W32031958 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 26 Feb 2020 12:21:02 GMT Received: from d06av25.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 8BB2211C054; Wed, 26 Feb 2020 12:21:02 +0000 (GMT) Received: from d06av25.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id D36C611C04A; Wed, 26 Feb 2020 12:21:01 +0000 (GMT) Received: from localhost.localdomain (unknown [9.152.224.212]) by d06av25.portsmouth.uk.ibm.com (Postfix) with ESMTP; Wed, 26 Feb 2020 12:21:01 +0000 (GMT) From: Janosch Frank To: qemu-devel@nongnu.org Subject: [PATCH v5 18/18] docs: Add protvirt docs Date: Wed, 26 Feb 2020 07:20:38 -0500 X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200226122038.61481-1-frankja@linux.ibm.com> References: <20200226122038.61481-1-frankja@linux.ibm.com> MIME-Version: 1.0 X-TM-AS-GCONF: 00 x-cbid: 20022612-0028-0000-0000-000003DE2597 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 20022612-0029-0000-0000-000024A3415D Message-Id: <20200226122038.61481-19-frankja@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.138, 18.0.572 definitions=2020-02-26_04:2020-02-26, 2020-02-26 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 phishscore=0 adultscore=0 spamscore=0 impostorscore=0 suspectscore=1 bulkscore=0 mlxlogscore=999 clxscore=1015 priorityscore=1501 malwarescore=0 mlxscore=0 lowpriorityscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2001150001 definitions=main-2002260092 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x [generic] X-Received-From: 148.163.156.1 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: borntraeger@de.ibm.com, qemu-s390x@nongnu.org, cohuck@redhat.com, david@redhat.com Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" Lets add some documentation for the Protected VM functionality. Signed-off-by: Janosch Frank --- docs/system/index.rst | 1 + docs/system/protvirt.rst | 57 ++++++++++++++++++++++++++++++++++++++++ 2 files changed, 58 insertions(+) create mode 100644 docs/system/protvirt.rst diff --git a/docs/system/index.rst b/docs/system/index.rst index 1a4b2c82ac..d2dc63b973 100644 --- a/docs/system/index.rst +++ b/docs/system/index.rst @@ -16,3 +16,4 @@ Contents: qemu-block-drivers vfio-ap + protvirt diff --git a/docs/system/protvirt.rst b/docs/system/protvirt.rst new file mode 100644 index 0000000000..a1902cc47c --- /dev/null +++ b/docs/system/protvirt.rst @@ -0,0 +1,57 @@ +Protected Virtualization on s390x +================================= + +The memory and most of the register contents of Protected Virtual +Machines (PVMs) are inaccessible to the hypervisor, effectively +prohibiting VM introspection when the VM is running. At rest, PVMs are +encrypted and can only be decrypted by the firmware of specific IBM Z +machines. + + +Prerequisites +------------- + +To run PVMs, you need to have a machine with the Protected +Virtualization feature, which is indicated by the Ultravisor Call +facility (stfle bit 158). This is a KVM only feature, therefore you +need a KVM which is able to support PVMs and activate the Ultravisor +initialization by setting `prot_virt=1` on the kernel command line. + +If those requirements are met, the capability `KVM_CAP_S390_PROTECTED` +will indicate that KVM can support PVMs on that LPAR. + + +QEMU Settings +------------- + +To indicate to the VM that it can move into protected mode, the +`Unpack facility` (stfle bit 161) needs to be part of the cpu model of +the VM. + +All I/O devices need to use the IOMMU. +Passthrough (vfio) devices are currently not supported. + +Host huge page backings are not supported. The guest however can use +huge pages as indicated by its facilities. + + +Boot Process +------------ + +A secure guest image can be both booted from disk and using the QEMU +command line. Booting from disk is done by the unmodified s390-ccw +BIOS. I.e., the bootmap is interpreted and a number of components is +read into memory and control is transferred to one of the components +(zipl stage3), which does some fixups and then transfers control to +some program residing in guest memory, which is normally the OS +kernel. The secure image has another component prepended (stage3a) +which uses the new diag308 subcodes 8 and 10 to trigger the transition +into secure mode. + +Booting from the command line requires that the file passed +via -kernel has the same memory layout as would result from the disk +boot. This memory layout includes the encrypted components (kernel, +initrd, cmdline), the stage3a loader and metadata. In case this boot +method is used, the command line options -initrd and -cmdline are +ineffective. The preparation of secure guest image is done by a +program (name tbd) of the s390-tools package.