From patchwork Wed Mar 18 14:30:46 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Janosch Frank X-Patchwork-Id: 1257546 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=linux.ibm.com 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 ozlabs.org (Postfix) with ESMTPS id 48jCL41kKLz9sRf for ; Thu, 19 Mar 2020 01:37:16 +1100 (AEDT) Received: from localhost ([::1]:51560 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jEZon-0002IF-EX for incoming@patchwork.ozlabs.org; Wed, 18 Mar 2020 10:37:13 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:58967) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jEZjW-0003Er-8d for qemu-devel@nongnu.org; Wed, 18 Mar 2020 10:31:47 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1jEZjU-0002Qq-Nt for qemu-devel@nongnu.org; Wed, 18 Mar 2020 10:31:46 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:31270) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1jEZjU-0001xb-E9 for qemu-devel@nongnu.org; Wed, 18 Mar 2020 10:31:44 -0400 Received: from pps.filterd (m0187473.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 02IEU9bp142788 for ; Wed, 18 Mar 2020 10:31:33 -0400 Received: from e06smtp04.uk.ibm.com (e06smtp04.uk.ibm.com [195.75.94.100]) by mx0a-001b2d01.pphosted.com with ESMTP id 2yu8ad9tuy-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Wed, 18 Mar 2020 10:31:33 -0400 Received: from localhost by e06smtp04.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, 18 Mar 2020 14:31:28 -0000 Received: from d06av24.portsmouth.uk.ibm.com (d06av24.portsmouth.uk.ibm.com [9.149.105.60]) by b06cxnps4074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 02IEVR5F48496802 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 18 Mar 2020 14:31:27 GMT Received: from d06av24.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 7A6DB42049; Wed, 18 Mar 2020 14:31:27 +0000 (GMT) Received: from d06av24.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 689524204D; Wed, 18 Mar 2020 14:31:26 +0000 (GMT) Received: from localhost.localdomain (unknown [9.145.78.199]) by d06av24.portsmouth.uk.ibm.com (Postfix) with ESMTP; Wed, 18 Mar 2020 14:31:26 +0000 (GMT) From: Janosch Frank To: qemu-devel@nongnu.org Subject: [PATCH v10 15/16] docs: system: Add protvirt docs Date: Wed, 18 Mar 2020 10:30:46 -0400 X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200318143047.2335-1-frankja@linux.ibm.com> References: <20200318143047.2335-1-frankja@linux.ibm.com> MIME-Version: 1.0 X-TM-AS-GCONF: 00 x-cbid: 20031814-0016-0000-0000-000002F33EB3 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 20031814-0017-0000-0000-00003356C41C Message-Id: <20200318143047.2335-16-frankja@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.138, 18.0.645 definitions=2020-03-18_06:2020-03-18, 2020-03-18 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 adultscore=0 lowpriorityscore=0 mlxscore=0 clxscore=1015 priorityscore=1501 spamscore=0 malwarescore=0 impostorscore=0 suspectscore=1 bulkscore=0 mlxlogscore=999 phishscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2003020000 definitions=main-2003180067 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+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" Let's add some documentation for the Protected VM functionality. Signed-off-by: Janosch Frank Acked-by: David Hildenbrand Reviewed-by: Claudio Imbrenda Acked-by: Christian Borntraeger Reviewed-by: Cornelia Huck --- docs/system/s390x/protvirt.rst | 59 ++++++++++++++++++++++++++++++++++ docs/system/target-s390x.rst | 5 +++ 2 files changed, 64 insertions(+) create mode 100644 docs/system/s390x/protvirt.rst diff --git a/docs/system/s390x/protvirt.rst b/docs/system/s390x/protvirt.rst new file mode 100644 index 0000000000000000..71172511632f7bcb --- /dev/null +++ b/docs/system/s390x/protvirt.rst @@ -0,0 +1,59 @@ +Protected Virtualization on s390x +================================= + +The memory and most of the registers of Protected Virtual Machines +(PVMs) are encrypted or 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, represented by an +entity called Ultravisor, of specific IBM Z machines. + + +Prerequisites +------------- + +To run PVMs, a machine with the Protected Virtualization feature, as +indicated by the Ultravisor Call facility (stfle bit 158), is +required. The Ultravisor needs to be initialized at boot by setting +`prot_virt=1` on the host's kernel command line. + +Running PVMs requires using the KVM hypervisor. + +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 transition into protected mode, the +`Unpack facility` (stfle bit 161 represented by the feature +`unpack`/`S390_FEAT_UNPACK`) 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. However guests can use huge +pages as indicated by its facilities. + + +Boot Process +------------ + +A secure guest image can either be loaded from disk or supplied on the +QEMU command line. Booting from disk is done by the unmodified +s390-ccw BIOS. I.e., the bootmap is interpreted, multiple components +are read into memory and control is transferred to one of the +components (zipl stage3). Stage3 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) that uses the new diag308 subcodes 8 and 10 to trigger the +transition into secure mode. + +Booting from the image supplied on the QEMU 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 a PVM +image is done via the `genprotimg` tool from the s390-tools package. diff --git a/docs/system/target-s390x.rst b/docs/system/target-s390x.rst index 4c8b7cdd66154d26..8d97158dc804af1c 100644 --- a/docs/system/target-s390x.rst +++ b/docs/system/target-s390x.rst @@ -24,3 +24,8 @@ or vfio-ap is also available. .. toctree:: s390x/vfio-ap +Architectural features +~~~~~~~~ + +.. toctree:: + s390x/protvirt