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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 83127C61DA4 for ; Mon, 6 Mar 2023 15:13:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229732AbjCFPNl (ORCPT ); Mon, 6 Mar 2023 10:13:41 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33406 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229770AbjCFPNj (ORCPT ); Mon, 6 Mar 2023 10:13:39 -0500 Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com [148.163.156.1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7BBC017CD4 for ; Mon, 6 Mar 2023 07:13:38 -0800 (PST) Received: from pps.filterd (m0098404.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 326EwPnr023319 for ; Mon, 6 Mar 2023 15:13:38 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : content-transfer-encoding : mime-version; s=pp1; bh=0BnADujkeHlDSfH1mIBNsfYo0ccU8SGB8I7oZSo/juk=; b=jq+7Jct+6+kzFurH2d0+cfD172DCh0YOJV6CX8TvUkgjp7k0AKLUKO4L9DXUjSajggt4 0YrXM1uzZLb3OKc3cX9isDfnmkgTsauZ/90MpN8VtYKQK+T4ucE6mzCoIzDfIb4nMKnC xFv1roc0i7t/byODblFwsHVBl2phAthJbMgZCIxve/di3WFWLaI4kg1rljwVq6JA3QbW qYd009qEHfz5vzkz+ZhD4duWMJMoauL65jShcVUsTkEuRvtaR25iziFBAWYTbxwoSYlt 1wG8Y26NUlCAA0LigxD05b3n65NHcqtwZSpdV/6T30Vp7731qnBrYi6l4p27i/7nXtDs lA== Received: from ppma04fra.de.ibm.com (6a.4a.5195.ip4.static.sl-reverse.com [149.81.74.106]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 3p500dpe4j-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT) for ; Mon, 06 Mar 2023 15:13:37 +0000 Received: from pps.filterd (ppma04fra.de.ibm.com [127.0.0.1]) by ppma04fra.de.ibm.com (8.17.1.19/8.17.1.19) with ESMTP id 325KPkYL012299 for ; Mon, 6 Mar 2023 15:13:35 GMT Received: from smtprelay06.fra02v.mail.ibm.com ([9.218.2.230]) by ppma04fra.de.ibm.com (PPS) with ESMTPS id 3p41b0ta04-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT) for ; Mon, 06 Mar 2023 15:13:35 +0000 Received: from smtpav06.fra02v.mail.ibm.com (smtpav06.fra02v.mail.ibm.com [10.20.54.105]) by smtprelay06.fra02v.mail.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 326FDV6g31064682 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 6 Mar 2023 15:13:31 GMT Received: from smtpav06.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id C8CD520049; Mon, 6 Mar 2023 15:13:31 +0000 (GMT) Received: from smtpav06.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 9B2C320043; Mon, 6 Mar 2023 15:13:31 +0000 (GMT) Received: from t35lp63.lnxne.boe (unknown [9.152.108.100]) by smtpav06.fra02v.mail.ibm.com (Postfix) with ESMTP; Mon, 6 Mar 2023 15:13:31 +0000 (GMT) From: Nico Boehr To: stable@vger.kernel.org Cc: frankja@linux.ibm.com, imbrenda@linux.ibm.com Subject: [PATCH 5.4.y] KVM: s390: disable migration mode when dirty tracking is disabled Date: Mon, 6 Mar 2023 16:13:31 +0100 Message-Id: <20230306151331.4531-1-nrb@linux.ibm.com> X-Mailer: git-send-email 2.39.1 In-Reply-To: <167810000636131@kroah.com> References: <167810000636131@kroah.com> X-TM-AS-GCONF: 00 X-Proofpoint-ORIG-GUID: _lQlWI9sbeVdnu1stAwpA694pGP-nON6 X-Proofpoint-GUID: _lQlWI9sbeVdnu1stAwpA694pGP-nON6 Content-Transfer-Encoding: 8bit X-Proofpoint-UnRewURL: 0 URL was un-rewritten MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.219,Aquarius:18.0.942,Hydra:6.0.573,FMLib:17.11.170.22 definitions=2023-03-06_08,2023-03-06_01,2023-02-09_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 phishscore=0 impostorscore=0 clxscore=1015 lowpriorityscore=0 bulkscore=0 suspectscore=0 adultscore=0 malwarescore=0 priorityscore=1501 mlxlogscore=938 mlxscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2212070000 definitions=main-2303060133 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org Migration mode is a VM attribute which enables tracking of changes in storage attributes (PGSTE). It assumes dirty tracking is enabled on all memslots to keep a dirty bitmap of pages with changed storage attributes. When enabling migration mode, we currently check that dirty tracking is enabled for all memslots. However, userspace can disable dirty tracking without disabling migration mode. Since migration mode is pointless with dirty tracking disabled, disable migration mode whenever userspace disables dirty tracking on any slot. Also update the documentation to clarify that dirty tracking must be enabled when enabling migration mode, which is already enforced by the code in kvm_s390_vm_start_migration(). Also highlight in the documentation for KVM_S390_GET_CMMA_BITS that it can now fail with -EINVAL when dirty tracking is disabled while migration mode is on. Move all the error codes to a table so this stays readable. To disable migration mode, slots_lock should be held, which is taken in kvm_set_memory_region() and thus held in kvm_arch_prepare_memory_region(). Restructure the prepare code a bit so all the sanity checking is done before disabling migration mode. This ensures migration mode isn't disabled when some sanity check fails. Cc: stable@vger.kernel.org Fixes: 190df4a212a7 ("KVM: s390: CMMA tracking, ESSA emulation, migration mode") Signed-off-by: Nico Boehr Reviewed-by: Janosch Frank Reviewed-by: Claudio Imbrenda Link: https://lore.kernel.org/r/20230127140532.230651-2-nrb@linux.ibm.com Message-Id: <20230127140532.230651-2-nrb@linux.ibm.com> [frankja@linux.ibm.com: fixed commit message typo, moved api.rst error table upwards] Signed-off-by: Janosch Frank (cherry picked from commit f2d3155e2a6bac44d16f04415a321e8707d895c6) Signed-off-by: Nico Boehr --- Documentation/virt/kvm/api.txt | 18 ++++++++++++------ Documentation/virt/kvm/devices/vm.txt | 4 ++++ arch/s390/kvm/kvm-s390.c | 16 ++++++++++++++++ 3 files changed, 32 insertions(+), 6 deletions(-) diff --git a/Documentation/virt/kvm/api.txt b/Documentation/virt/kvm/api.txt index fd22224853e5..180475bcd671 100644 --- a/Documentation/virt/kvm/api.txt +++ b/Documentation/virt/kvm/api.txt @@ -3615,6 +3615,18 @@ Type: vm ioctl Parameters: struct kvm_s390_cmma_log (in, out) Returns: 0 on success, a negative value on error +Errors: + + ====== ============================================================= + ENOMEM not enough memory can be allocated to complete the task + ENXIO if CMMA is not enabled + EINVAL if KVM_S390_CMMA_PEEK is not set but migration mode was not enabled + EINVAL if KVM_S390_CMMA_PEEK is not set but dirty tracking has been + disabled (and thus migration mode was automatically disabled) + EFAULT if the userspace address is invalid or if no page table is + present for the addresses (e.g. when using hugepages). + ====== ============================================================= + This ioctl is used to get the values of the CMMA bits on the s390 architecture. It is meant to be used in two scenarios: - During live migration to save the CMMA values. Live migration needs @@ -3691,12 +3703,6 @@ mask is unused. values points to the userspace buffer where the result will be stored. -This ioctl can fail with -ENOMEM if not enough memory can be allocated to -complete the task, with -ENXIO if CMMA is not enabled, with -EINVAL if -KVM_S390_CMMA_PEEK is not set but migration mode was not enabled, with --EFAULT if the userspace address is invalid or if no page table is -present for the addresses (e.g. when using hugepages). - 4.108 KVM_S390_SET_CMMA_BITS Capability: KVM_CAP_S390_CMMA_MIGRATION diff --git a/Documentation/virt/kvm/devices/vm.txt b/Documentation/virt/kvm/devices/vm.txt index 4ffb82b02468..38ec142a4a84 100644 --- a/Documentation/virt/kvm/devices/vm.txt +++ b/Documentation/virt/kvm/devices/vm.txt @@ -254,6 +254,10 @@ Allows userspace to start migration mode, needed for PGSTE migration. Setting this attribute when migration mode is already active will have no effects. +Dirty tracking must be enabled on all memslots, else -EINVAL is returned. When +dirty tracking is disabled on any memslot, migration mode is automatically +stopped. + Parameters: none Returns: -ENOMEM if there is not enough free memory to start migration mode -EINVAL if the state of the VM is invalid (e.g. no memory defined) diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index 49dc00d82e5e..9ade970b4232 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -4527,6 +4527,22 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm, if (mem->guest_phys_addr + mem->memory_size > kvm->arch.mem_limit) return -EINVAL; + if (!kvm->arch.migration_mode) + return 0; + + /* + * Turn off migration mode when: + * - userspace creates a new memslot with dirty logging off, + * - userspace modifies an existing memslot (MOVE or FLAGS_ONLY) and + * dirty logging is turned off. + * Migration mode expects dirty page logging being enabled to store + * its dirty bitmap. + */ + if (change != KVM_MR_DELETE && + !(mem->flags & KVM_MEM_LOG_DIRTY_PAGES)) + WARN(kvm_s390_vm_stop_migration(kvm), + "Failed to stop migration mode"); + return 0; } -- 2.39.1