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=-11.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 AD96AC432BE for ; Wed, 18 Aug 2021 13:26:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9824360F4C for ; Wed, 18 Aug 2021 13:26:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237130AbhHRN1I (ORCPT ); Wed, 18 Aug 2021 09:27:08 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:32826 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S237008AbhHRN1F (ORCPT ); Wed, 18 Aug 2021 09:27:05 -0400 Received: from pps.filterd (m0098419.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.43/8.16.0.43) with SMTP id 17ID2unw131842; Wed, 18 Aug 2021 09:26:28 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=from : to : cc : subject : date : message-id : mime-version : content-transfer-encoding; s=pp1; bh=mUOjUwhOg1TZwyuf8+PsacD68XEMl2xjesMrps7k50c=; b=mq0PAKjbq+jRma050zrpbvRRAcTjVxCIlN0Fauqg8IKeynwddgE8/HfW6/x5eDyWjgJM z7DoSoacuVL2unfe91H8l6+NCdPViFwN4MySYYhyDLm6FgjMT70BBIfPdRHj1y01rEDe KPHa4iLlCzyFK8rOim9SU9Dobo8Gj8rwkQRBials3BhKb9Qg5tewSxt/UW6VP37pOCV7 PWHjAvuDrHfgKKac2hOWkGl0nx+P/ZTq3DCTTgJI4Q8mfXFli6Kt7UOyp+BJ6fcxIMEZ mdppecdNKgvqQeAwIGWepcLorQt0yMMkVKJXcGnqaK4BLaZ+SPEajzo6QRaW3dHeB5Qe 0A== Received: from pps.reinject (localhost [127.0.0.1]) by mx0b-001b2d01.pphosted.com with ESMTP id 3agp1yknj2-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 18 Aug 2021 09:26:27 -0400 Received: from m0098419.ppops.net (m0098419.ppops.net [127.0.0.1]) by pps.reinject (8.16.0.43/8.16.0.43) with SMTP id 17ID3S7Y137158; Wed, 18 Aug 2021 09:26:27 -0400 Received: from ppma06fra.de.ibm.com (48.49.7a9f.ip4.static.sl-reverse.com [159.122.73.72]) by mx0b-001b2d01.pphosted.com with ESMTP id 3agp1yknh3-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 18 Aug 2021 09:26:27 -0400 Received: from pps.filterd (ppma06fra.de.ibm.com [127.0.0.1]) by ppma06fra.de.ibm.com (8.16.1.2/8.16.1.2) with SMTP id 17IDCPRS007447; Wed, 18 Aug 2021 13:26:25 GMT Received: from b06cxnps3075.portsmouth.uk.ibm.com (d06relay10.portsmouth.uk.ibm.com [9.149.109.195]) by ppma06fra.de.ibm.com with ESMTP id 3ae53hdrjq-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 18 Aug 2021 13:26:25 +0000 Received: from d06av22.portsmouth.uk.ibm.com (d06av22.portsmouth.uk.ibm.com [9.149.105.58]) by b06cxnps3075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 17IDQLG256754586 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 18 Aug 2021 13:26:21 GMT Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 0318F4C062; Wed, 18 Aug 2021 13:26:21 +0000 (GMT) Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 7219F4C059; Wed, 18 Aug 2021 13:26:20 +0000 (GMT) Received: from p-imbrenda.bredband2.com (unknown [9.145.14.177]) by d06av22.portsmouth.uk.ibm.com (Postfix) with ESMTP; Wed, 18 Aug 2021 13:26:20 +0000 (GMT) From: Claudio Imbrenda To: kvm@vger.kernel.org Cc: cohuck@redhat.com, borntraeger@de.ibm.com, frankja@linux.ibm.com, thuth@redhat.com, pasic@linux.ibm.com, david@redhat.com, linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, Ulrich.Weigand@de.ibm.com Subject: [PATCH v4 00/14] KVM: s390: pv: implement lazy destroy for reboot Date: Wed, 18 Aug 2021 15:26:06 +0200 Message-Id: <20210818132620.46770-1-imbrenda@linux.ibm.com> X-Mailer: git-send-email 2.31.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 X-Proofpoint-ORIG-GUID: JR3QSBUheSgf3km6gZoA80_7BqPyroUP X-Proofpoint-GUID: o2RMMCMGx3hGSPMf39ierqi7Wijms6LO X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.391,18.0.790 definitions=2021-08-18_04:2021-08-17,2021-08-18 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 mlxlogscore=999 clxscore=1015 priorityscore=1501 lowpriorityscore=0 phishscore=0 malwarescore=0 mlxscore=0 bulkscore=0 impostorscore=0 suspectscore=0 spamscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2107140000 definitions=main-2108180082 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Previously, when a protected VM was rebooted or when it was shut down, its memory was made unprotected, and then the protected VM itself was destroyed. Looping over the whole address space can take some time, considering the overhead of the various Ultravisor Calls (UVCs). This means that a reboot or a shutdown would take a potentially long amount of time, depending on the amount of used memory. This patchseries implements a deferred destroy mechanism for protected guests. When a protected guest is destroyed, its memory is cleared in background, allowing the guest to restart or terminate significantly faster than before. There are 2 possibilities when a protected VM is torn down: * it still has an address space associated (reboot case) * it does not have an address space anymore (shutdown case) For the reboot case, the reference count of the mm is increased, and then a background thread is started to clean up. Once the thread went through the whole address space, the protected VM is actually destroyed. This means that the same address space can have memory belonging to more than one protected guest, although only one will be running, the others will in fact not even have any CPUs. The shutdown case is more controversial, and it will be dealt with in a future patchseries. When a guest is destroyed, its memory still counts towards its memory control group until it's actually freed (I tested this experimentally) v3->v4 * added patch 2 * split patch 3 * removed the shutdown part -- will be a separate patchseries * moved the patch introducing the module parameter v2->v3 * added definitions for CC return codes for the UVC instruction * improved make_secure_pte: - renamed rc to cc - added comments to explain why returning -EAGAIN is ok * fixed kvm_s390_pv_replace_asce and kvm_s390_pv_remove_old_asce: - renamed - added locking - moved to gmap.c * do proper error management in do_secure_storage_access instead of trying again hoping to get a different exception * fix outdated patch descriptions v1->v2 * rebased on a more recent kernel * improved/expanded some patch descriptions * improves/expanded some comments * added patch 1, which prevents stall notification when the system is under heavy load. * rename some members of struct deferred_priv to improve readability * avoid an use-after-free bug of the struct mm in case of shutdown * add missing return when lazy destroy is disabled * add support for OOM notifier Claudio Imbrenda (14): KVM: s390: pv: add macros for UVC CC values KVM: s390: pv: avoid double free of sida page KVM: s390: pv: avoid stalls for kvm_s390_pv_init_vm KVM: s390: pv: avoid stalls when making pages secure KVM: s390: pv: leak the ASCE page when destroy fails KVM: s390: pv: properly handle page flags for protected guests KVM: s390: pv: handle secure storage violations for protected guests KVM: s390: pv: handle secure storage exceptions for normal guests KVM: s390: pv: refactor s390_reset_acc KVM: s390: pv: usage counter instead of flag KVM: s390: pv: add export before import KVM: s390: pv: module parameter to fence lazy destroy KVM: s390: pv: lazy destroy for reboot KVM: s390: pv: avoid export before import if possible arch/s390/include/asm/gmap.h | 6 +- arch/s390/include/asm/pgtable.h | 9 +- arch/s390/include/asm/uv.h | 16 ++- arch/s390/kernel/uv.c | 115 ++++++++++++++++++-- arch/s390/kvm/kvm-s390.c | 6 +- arch/s390/kvm/kvm-s390.h | 2 +- arch/s390/kvm/pv.c | 185 ++++++++++++++++++++++++++++---- arch/s390/mm/fault.c | 20 +++- arch/s390/mm/gmap.c | 141 +++++++++++++++++++----- 9 files changed, 434 insertions(+), 66 deletions(-) -- 2.31.1