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=-0.8 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 30262ECE560 for ; Mon, 24 Sep 2018 18:44:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D231D2098A for ; Mon, 24 Sep 2018 18:44:06 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D231D2098A 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 S2387739AbeIYArf (ORCPT ); Mon, 24 Sep 2018 20:47:35 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:53702 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730253AbeIYAre (ORCPT ); Mon, 24 Sep 2018 20:47:34 -0400 Received: from pps.filterd (m0098409.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w8OIi2X9031491 for ; Mon, 24 Sep 2018 14:44:03 -0400 Received: from e32.co.us.ibm.com (e32.co.us.ibm.com [32.97.110.150]) by mx0a-001b2d01.pphosted.com with ESMTP id 2mq3jsvyv9-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Mon, 24 Sep 2018 14:44:03 -0400 Received: from localhost by e32.co.us.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) Mon, 24 Sep 2018 12:43:50 -0600 Received: from b03ledav005.gho.boulder.ibm.com (b03ledav005.gho.boulder.ibm.com [9.17.130.236]) by b03cxnp08025.gho.boulder.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id w8OIhm8523134452 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Mon, 24 Sep 2018 11:43:48 -0700 Received: from b03ledav005.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 0A8B4BE054; Mon, 24 Sep 2018 12:43:48 -0600 (MDT) Received: from b03ledav005.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 116A7BE051; Mon, 24 Sep 2018 12:43:43 -0600 (MDT) Received: from oc8043147753.ibm.com (unknown [9.85.130.123]) by b03ledav005.gho.boulder.ibm.com (Postfix) with ESMTP; Mon, 24 Sep 2018 12:43:43 -0600 (MDT) Subject: Re: [PATCH v10 11/26] s390: vfio-ap: implement mediated device open callback To: David Hildenbrand , Tony Krowiak , linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: freude@de.ibm.com, schwidefsky@de.ibm.com, heiko.carstens@de.ibm.com, borntraeger@de.ibm.com, cohuck@redhat.com, kwankhede@nvidia.com, bjsdjshi@linux.vnet.ibm.com, pbonzini@redhat.com, alex.williamson@redhat.com, pmorel@linux.vnet.ibm.com, alifm@linux.vnet.ibm.com, mjrosato@linux.vnet.ibm.com, jjherne@linux.vnet.ibm.com, thuth@redhat.com, pasic@linux.vnet.ibm.com, berrange@redhat.com, fiuczy@linux.vnet.ibm.com, buendgen@de.ibm.com, frankja@linux.ibm.com References: <1536781396-13601-1-git-send-email-akrowiak@linux.vnet.ibm.com> <1536781396-13601-12-git-send-email-akrowiak@linux.vnet.ibm.com> <09a6b9e5-e335-14cf-debd-de0f92dafd5e@redhat.com> <69b5e3d3-5d44-37c0-ca10-720345852134@redhat.com> From: Tony Krowiak Date: Mon, 24 Sep 2018 14:43:43 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.2.0 MIME-Version: 1.0 In-Reply-To: <69b5e3d3-5d44-37c0-ca10-720345852134@redhat.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 x-cbid: 18092418-0004-0000-0000-00001490F06F X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00009764; HX=3.00000242; KW=3.00000007; PH=3.00000004; SC=3.00000267; SDB=6.01093071; UDB=6.00564923; IPR=6.00873108; MB=3.00023485; MTD=3.00000008; XFM=3.00000015; UTC=2018-09-24 18:43:54 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18092418-0005-0000-0000-000088ECC539 Message-Id: <9f227089-8135-922c-fbe0-015085767a18@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2018-09-24_11:,, 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-1809240178 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 09/24/2018 02:40 PM, David Hildenbrand wrote: > On 24/09/2018 18:07, Tony Krowiak wrote: >> On 09/24/2018 04:40 AM, David Hildenbrand wrote: >>> >>>> /** >>>> - * Verify that the AP instructions are available on the guest. This is >>>> indicated >>>> - * via the KVM_S390_VM_CPU_FEAT_AP CPU model feature. >>>> + * Verify that the AP instructions are being interpreted by firmware >>>> for the >>>> + * guest. This is indicated by the kvm->arch.crypto.apie flag. >>>> */ >>>> static int kvm_ap_validate_crypto_setup(struct kvm *kvm) >>>> { >>>> - if (test_bit_inv(KVM_S390_VM_CPU_FEAT_AP, kvm->arch.cpu_feat)) >>>> + if (kvm->arch.crypto.apie) >>>> return 0; >>> >>> I wonder if this check makes sense, because apie can be toggled during >>> runtime. I guess it would be sufficient to check if the ap control block >>> is available and apie is supported by the HW. >> >> I am not clear about what you are getting at here, but I'll attempt >> to respond. There is no need to check if the AP control block (CRYCB) >> is available as the address is set in the CRYCBD three instructions >> above, even if AP instructions are not available. Regarding whether apie >> is supported by the hardware, the value of vcpu->kvm->arch.crypto.apie >> can not be set unless it is supported by the HW. In the patch (24/26) >> that provides the VM attributes to toggle this value, it can only be >> turned on if the AP instructions are available. I might also note that >> the kvm_ap_validate_crypto_setup() function is called whenever one of >> the VM crypto attributes is changed, so it makes sense that decisions >> made in this function are based on a change to a VM crypto attribute. In >> my first pass at changing this function, I checked >> ap_instructions_available() here, but after considering all of the >> above, it made sense to me to check the apie flag. >> > > I prefer ap_instructions_available(). As I said, kvm->arch.crypto.apie > is a moving target. Okay then. >