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 1B6B2C43381 for ; Tue, 19 Feb 2019 19:51:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DD5E02146F for ; Tue, 19 Feb 2019 19:51:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727426AbfBSTvJ (ORCPT ); Tue, 19 Feb 2019 14:51:09 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:50900 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725963AbfBSTvI (ORCPT ); Tue, 19 Feb 2019 14:51:08 -0500 Received: from pps.filterd (m0098419.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x1JJjZQu054798 for ; Tue, 19 Feb 2019 14:51:07 -0500 Received: from e06smtp05.uk.ibm.com (e06smtp05.uk.ibm.com [195.75.94.101]) by mx0b-001b2d01.pphosted.com with ESMTP id 2qrqx3913t-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Tue, 19 Feb 2019 14:51:07 -0500 Received: from localhost by e06smtp05.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) Tue, 19 Feb 2019 19:51:01 -0000 Received: from d06av26.portsmouth.uk.ibm.com (d06av26.portsmouth.uk.ibm.com [9.149.105.62]) by b06cxnps4076.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x1JJoxPi21102746 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Tue, 19 Feb 2019 19:50:59 GMT Received: from d06av26.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id C4E57AE04D; Tue, 19 Feb 2019 19:50:59 +0000 (GMT) Received: from d06av26.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 12F28AE05D; Tue, 19 Feb 2019 19:50:59 +0000 (GMT) Received: from [9.145.25.7] (unknown [9.145.25.7]) by d06av26.portsmouth.uk.ibm.com (Postfix) with ESMTP; Tue, 19 Feb 2019 19:50:59 +0000 (GMT) Reply-To: pmorel@linux.ibm.com Subject: Re: [PATCH v3 2/9] s390: ap: kvm: setting a hook for PQAP instructions To: Cornelia Huck Cc: Tony Krowiak , borntraeger@de.ibm.com, alex.williamson@redhat.com, linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org, kvm@vger.kernel.org, frankja@linux.ibm.com, pasic@linux.ibm.com, david@redhat.com, schwidefsky@de.ibm.com, heiko.carstens@de.ibm.com, freude@linux.ibm.com, mimu@linux.ibm.com References: <1550152269-6317-1-git-send-email-pmorel@linux.ibm.com> <1550152269-6317-3-git-send-email-pmorel@linux.ibm.com> <4b21f059-1d37-f341-bac7-5b1fe0d06521@linux.ibm.com> <20190218234235.7d9f547c.cohuck@redhat.com> From: Pierre Morel Date: Tue, 19 Feb 2019 20:50:58 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.4.0 MIME-Version: 1.0 In-Reply-To: <20190218234235.7d9f547c.cohuck@redhat.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: 19021919-0020-0000-0000-00000318BF24 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19021919-0021-0000-0000-0000216A06F4 Message-Id: <74d812c6-bf83-0fb0-8fc3-af1341b0ae3c@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-02-19_13:,, 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=544 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1902190139 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 18/02/2019 23:42, Cornelia Huck wrote: > On Mon, 18 Feb 2019 19:29:10 +0100 > Pierre Morel wrote: > >> On 15/02/2019 23:02, Tony Krowiak wrote: >>> On 2/14/19 8:51 AM, Pierre Morel wrote: > >>>> +/* >>>> + * handle_pqap: Handling pqap interception >>>> + * @vcpu: the vcpu having issue the pqap instruction >>>> + * >>>> + * This callback only handles PQAP/AQIC instruction and >>>> + * calls a dedicated callback for this instruction if >>>> + * a driver did register one in the CRYPTO satellite of the >>>> + * SIE block. >>>> + * >>>> + * Do not change the behavior if, return -EOPNOTSUPP if: >>>> + * - the hook is not used do not change the behavior. >>>> + * - AP instructions are not available or not available to the guest >>>> + * - the instruction is not PQAP with function code indicating >>>> + *   AQIC do not change the previous behavior. >>>> + * >>>> + * For PQAP/AQIC instruction, verify privilege and specifications >>>> + * >>>> + * return the value returned by the callback. >>>> + */ >>>> +static int handle_pqap(struct kvm_vcpu *vcpu) >>>> +{ >>>> +    uint8_t fc; >>>> + >>>> +    /* Verify that the hook callback is registered */ >>>> +    if (!vcpu->kvm->arch.crypto.pqap_hook) >>>> +        return -EOPNOTSUPP; >>>> +    /* Verify that the AP instruction are available */ >>>> +    if (!ap_instructions_available()) >>>> +        return -EOPNOTSUPP; >>>> +    /* Verify that the guest is allowed to use AP instructions */ >>>> +    if (!(vcpu->arch.sie_block->eca & ECA_APIE)) >>>> +        return -EOPNOTSUPP; >>>> +    /* Verify that the function code is AQIC */ >>>> +    fc = vcpu->run->s.regs.gprs[0] >> 24; >>>> +    if (fc != 0x03) >>>> +        return -EOPNOTSUPP; >>> >>> This does not belong here. Function code 3 is one of 7 function codes >>> that can be sent with the PQAP instruction. This belongs in the PQAP >>> hook code. >> >> On one hand, effectively I would prefer to put the code in the VFIO >> driver code. >> On the other hand, doing this would lead to export the code for >> test_kvm_facility() and kvm_s390_inject_program_int() from the kvm-s390.h >> >> I choose not to export these functions from the KVM code. >> >> Would like opinion from KVM maintainers? > > Looking at this (and without access to the specification...), I think > the check for problem state makes sense in here (if this applies to all > PQAP functions equally, which seems likely). The check for the facility > makes more sense in the handler. You can probably still inject the > specification exception here if you use a clever return code. > If there is no objection on exporting the KVM functions... I can do this. > Another option: Provide a way to register a callback per function code; > this allows you to still do the check here and extend it later for > other function codes (which will probably be indicated by another > facility). I like this option even better. Regards, Pierre -- Pierre Morel Linux/KVM/QEMU in Böblingen - Germany