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 33CE6C43381 for ; Thu, 21 Feb 2019 12:40:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 02B552086C for ; Thu, 21 Feb 2019 12:40:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727970AbfBUMkm (ORCPT ); Thu, 21 Feb 2019 07:40:42 -0500 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:39774 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725845AbfBUMkl (ORCPT ); Thu, 21 Feb 2019 07:40:41 -0500 Received: from pps.filterd (m0098394.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x1LCda1r061663 for ; Thu, 21 Feb 2019 07:40:41 -0500 Received: from e06smtp01.uk.ibm.com (e06smtp01.uk.ibm.com [195.75.94.97]) by mx0a-001b2d01.pphosted.com with ESMTP id 2qsupvhapj-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Thu, 21 Feb 2019 07:40:40 -0500 Received: from localhost by e06smtp01.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 21 Feb 2019 12:40:38 -0000 Received: from b06cxnps4074.portsmouth.uk.ibm.com (9.149.109.196) by e06smtp01.uk.ibm.com (192.168.101.131) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Thu, 21 Feb 2019 12:40:36 -0000 Received: from d06av22.portsmouth.uk.ibm.com (d06av22.portsmouth.uk.ibm.com [9.149.105.58]) by b06cxnps4074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x1LCeYnK30408786 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 21 Feb 2019 12:40:34 GMT Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id A30894C062; Thu, 21 Feb 2019 12:40:34 +0000 (GMT) Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id F27EF4C04E; Thu, 21 Feb 2019 12:40:33 +0000 (GMT) Received: from [9.152.224.140] (unknown [9.152.224.140]) by d06av22.portsmouth.uk.ibm.com (Postfix) with ESMTP; Thu, 21 Feb 2019 12:40:33 +0000 (GMT) Reply-To: pmorel@linux.ibm.com Subject: Re: [PATCH v3 2/9] s390: ap: kvm: setting a hook for PQAP instructions To: Tony Krowiak , Cornelia Huck Cc: 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> <74d812c6-bf83-0fb0-8fc3-af1341b0ae3c@linux.ibm.com> From: Pierre Morel Date: Thu, 21 Feb 2019 13:40:33 +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: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 x-cbid: 19022112-4275-0000-0000-000003123B14 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19022112-4276-0000-0000-000038206EE6 Message-Id: <50339bc0-50da-1a38-53a4-cf173fc387ea@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-02-21_07:,, 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=553 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1902210094 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 19/02/2019 23:36, Tony Krowiak wrote: > On 2/19/19 2:50 PM, Pierre Morel wrote: >> 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. > > I do not understand why you would have to export KVM functions to place > the check for FC 0x03 in the pqap hook? What am I missing here? Maybe > you misunderstood my comment? No I did not but in between I discovered an error in the handling of the interception of PQAP/AQIC. QEMU and KVM can both accept PQAP/AQIC even if the vfio_ap driver is not loaded. However now that the guest officially get the PQAP/AQIC instruction we need to handle the specification and operation exceptions inside KVM _before_ testing and even calling the driver hook. I will make the changes in the next iteration. Regards, Pierre -- Pierre Morel Linux/KVM/QEMU in Böblingen - Germany