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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=ham 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 A00D1C4321D for ; Thu, 23 Aug 2018 11:47:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 35870208DC for ; Thu, 23 Aug 2018 11:47:31 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 35870208DC Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.ibm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732206AbeHWPQt (ORCPT ); Thu, 23 Aug 2018 11:16:49 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:45374 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730163AbeHWPQm (ORCPT ); Thu, 23 Aug 2018 11:16:42 -0400 Received: from pps.filterd (m0098396.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w7NBiIl5072066 for ; Thu, 23 Aug 2018 07:47:21 -0400 Received: from e06smtp02.uk.ibm.com (e06smtp02.uk.ibm.com [195.75.94.98]) by mx0a-001b2d01.pphosted.com with ESMTP id 2m1svfxaam-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Thu, 23 Aug 2018 07:47:20 -0400 Received: from localhost by e06smtp02.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) Thu, 23 Aug 2018 12:47:14 +0100 Received: from d06av22.portsmouth.uk.ibm.com (d06av22.portsmouth.uk.ibm.com [9.149.105.58]) by b06cxnps4076.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id w7NBlCQL42926200 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Thu, 23 Aug 2018 11:47:12 GMT Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id D9E644C046; Thu, 23 Aug 2018 14:47:13 +0100 (BST) Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 71CE44C04E; Thu, 23 Aug 2018 14:47:13 +0100 (BST) Received: from [9.152.224.92] (unknown [9.152.224.92]) by d06av22.portsmouth.uk.ibm.com (Postfix) with ESMTP; Thu, 23 Aug 2018 14:47:13 +0100 (BST) Reply-To: pmorel@linux.ibm.com Subject: Re: [PATCH v3 3/3] KVM: s390: vsie: Make use of CRYCB FORMAT2 clear To: Janosch Frank , David Hildenbrand Cc: linux-kernel@vger.kernel.org, cohuck@redhat.com, linux-s390@vger.kernel.org, kvm@vger.kernel.org, akrowiak@linux.ibm.com, borntraeger@de.ibm.com, schwidefsky@de.ibm.com, heiko.carstens@de.ibm.com References: <1535019956-23539-1-git-send-email-pmorel@linux.ibm.com> <1535019956-23539-4-git-send-email-pmorel@linux.ibm.com> <912d013c-c925-fb3e-ed1d-2d778a60c189@linux.ibm.com> <58427761-072c-e420-a881-4decbe9088bb@linux.ibm.com> From: Pierre Morel Date: Thu, 23 Aug 2018 13:47:11 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <58427761-072c-e420-a881-4decbe9088bb@linux.ibm.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 x-cbid: 18082311-0008-0000-0000-00000265AB5E X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18082311-0009-0000-0000-000021CDF235 Message-Id: X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2018-08-23_05:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1807170000 definitions=main-1808230126 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 23/08/2018 13:33, Janosch Frank wrote: > On 8/23/18 1:21 PM, David Hildenbrand wrote: >> On 23.08.2018 13:05, Janosch Frank wrote: >>> On 8/23/18 12:25 PM, Pierre Morel wrote: >>>> The comment preceding the shadow_crycb function is >>>> misleading, we effectively accept FORMAT2 CRYCB in the >>>> guest. >>> >>> I beg to differ: >>> >>> if (!(crycbd_o & vcpu->arch.sie_block->crycbd & CRYCB_FORMAT1)) >>> return 0; >> >> FORMAT2 includes bit FORMAT1 (backwards compatible) > > Right, this check is very misleading because of the constant, we > effectively test against Format 0 and Format 2. > > Can we make this clearer by explicitly ANDing 0x01 or adding a comment? yes, done, I modified the comment in front of the function. > > Code makes sense: > Reviewed-by: Janosch Frank Thanks, regards, Pierre > >> >>> >>>> >>>> When using FORMAT2 in the host we do not need to or with >>>> FORMAT1. >>>> >>>> Signed-off-by: Pierre Morel >>>> --- >>>> arch/s390/kvm/vsie.c | 6 +++--- >>>> 1 file changed, 3 insertions(+), 3 deletions(-) >>>> >>>> diff --git a/arch/s390/kvm/vsie.c b/arch/s390/kvm/vsie.c >>>> index 38ea5da..e0e6fbf 100644 >>>> --- a/arch/s390/kvm/vsie.c >>>> +++ b/arch/s390/kvm/vsie.c >>>> @@ -140,7 +140,8 @@ static int prepare_cpuflags(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) >>>> * Create a shadow copy of the crycb block and setup key wrapping, if >>>> * requested for guest 3 and enabled for guest 2. >>>> * >>>> - * We only accept format-1 (no AP in g2), but convert it into format-2 >>>> + * We accept format-1 or format-2, but we treat it as a format-1 (no AP in g2), >>>> + * and we convert it into format-2 in the shadow CRYCB. >>>> * There is nothing to do for format-0. >>>> * >>>> * Returns: - 0 if shadowed or nothing to do >>>> @@ -179,8 +180,7 @@ static int shadow_crycb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) >>>> return set_validity_icpt(scb_s, 0x0035U); >>>> >>>> scb_s->ecb3 |= ecb3_flags; >>>> - scb_s->crycbd = ((__u32)(__u64) &vsie_page->crycb) | CRYCB_FORMAT1 | >>>> - CRYCB_FORMAT2; >>>> + scb_s->crycbd = ((__u32)(__u64) &vsie_page->crycb) | CRYCB_FORMAT2; >>> >>> That's purely cosmetic but valid. >>> >>>> >>>> /* xor both blocks in one run */ >>>> b1 = (unsigned long *) vsie_page->crycb.dea_wrapping_key_mask; >> >> Reviewed-by: David Hildenbrand >> > > -- Pierre Morel Linux/KVM/QEMU in Böblingen - Germany