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 578E8C4167D for ; Thu, 9 Nov 2023 13:11:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232103AbjKINL7 (ORCPT ); Thu, 9 Nov 2023 08:11:59 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50286 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230218AbjKINL5 (ORCPT ); Thu, 9 Nov 2023 08:11:57 -0500 Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com [148.163.156.1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0D5A81FEB; Thu, 9 Nov 2023 05:11:54 -0800 (PST) Received: from pps.filterd (m0356517.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 3A9DBBOP010759; Thu, 9 Nov 2023 13:11:54 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=message-id : date : mime-version : subject : to : cc : references : from : in-reply-to : content-type : content-transfer-encoding; s=pp1; bh=8G0FDVfBrCxKOxsk8y+IddWYDC94RL4fGkRSMZeh3WM=; b=tqTf21ISCNcldh/pEP3qu8kjI//Sn3eP49Ib4LeBQltts2xYJT6DHo8IXR9WrMK/t+Kr Prdnnobmuc93Z1W1dDDFaSC/ZZfMh7WMH8WtWYK5LSXD/lpvpuCb+Tfm0zH8tuZdvEPX A8CRoy3ypvYFm9olDiRmZii+bly6NkmxI9e2KdPJXWCYAm4FeFHnlU1/nROe4TvAfttE XFStR5a7BO4mKYL5hx8+UlwWM+0QlOd7/DWpPIcHxJYuD/Jsx+fZeEqcCiM/66pDL7pm r9Ue2zg4FcXjGzejkWPL5A8pNKjf2skrExODOipcQuh0HZ3tGejXNT39p8n4oNPPLrky gw== Received: from ppma22.wdc07v.mail.ibm.com (5c.69.3da9.ip4.static.sl-reverse.com [169.61.105.92]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 3u8ykeh1j6-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 09 Nov 2023 13:11:54 +0000 Received: from pps.filterd (ppma22.wdc07v.mail.ibm.com [127.0.0.1]) by ppma22.wdc07v.mail.ibm.com (8.17.1.19/8.17.1.19) with ESMTP id 3A9B12CJ028310; Thu, 9 Nov 2023 13:11:53 GMT Received: from smtprelay02.fra02v.mail.ibm.com ([9.218.2.226]) by ppma22.wdc07v.mail.ibm.com (PPS) with ESMTPS id 3u7w22kvxp-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 09 Nov 2023 13:11:53 +0000 Received: from smtpav06.fra02v.mail.ibm.com (smtpav06.fra02v.mail.ibm.com [10.20.54.105]) by smtprelay02.fra02v.mail.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 3A9DBolJ28181240 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 9 Nov 2023 13:11:50 GMT Received: from smtpav06.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id EB5D22004B; Thu, 9 Nov 2023 13:11:49 +0000 (GMT) Received: from smtpav06.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id AC7C720049; Thu, 9 Nov 2023 13:11:49 +0000 (GMT) Received: from [9.152.224.228] (unknown [9.152.224.228]) by smtpav06.fra02v.mail.ibm.com (Postfix) with ESMTP; Thu, 9 Nov 2023 13:11:49 +0000 (GMT) Message-ID: Date: Thu, 9 Nov 2023 14:11:48 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.15.1 Subject: Re: [PATCH v1 1/1] KVM: s390/mm: Properly reset no-dat Content-Language: en-US To: Claudio Imbrenda , kvm@vger.kernel.org Cc: linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org, frankja@linux.ibm.com, nrb@linux.ibm.com, nsg@linux.ibm.com, hca@linux.ibm.com, gor@linux.ibm.com, svens@linux.ibm.com, agordeev@linux.ibm.com, Gerald Schaefer References: <20231109123624.37314-1-imbrenda@linux.ibm.com> From: Christian Borntraeger In-Reply-To: <20231109123624.37314-1-imbrenda@linux.ibm.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 X-Proofpoint-ORIG-GUID: UrG5xTsnPoYJzUOA-xWRw1aNA0J6OCA7 X-Proofpoint-GUID: UrG5xTsnPoYJzUOA-xWRw1aNA0J6OCA7 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.272,Aquarius:18.0.987,Hydra:6.0.619,FMLib:17.11.176.26 definitions=2023-11-09_10,2023-11-09_01,2023-05-22_02 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 mlxscore=0 suspectscore=0 malwarescore=0 impostorscore=0 mlxlogscore=686 lowpriorityscore=0 clxscore=1011 adultscore=0 phishscore=0 priorityscore=1501 spamscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2311060000 definitions=main-2311090099 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Am 09.11.23 um 13:36 schrieb Claudio Imbrenda: > When the CMMA state needs to be reset, the no-dat bit also needs to be > reset. Failure to do so could cause issues in the guest, since the > guest expects the bit to be cleared after a reset. This happens during reset of a guest (or whenever QEMU calls the CLR_CMMA thingi). I think after reset a normal Linux guest has no DAT tables and very likely a cpu reset (with explicit full guest flush) will happen. It will very likely also set the CMMA state during boot before setting up its DAT tables. So for the normal reboot this should be ok. But I can imagine cases that would not be ok. So maybe add cc stable?