From patchwork Tue May 5 08:35:15 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christian Borntraeger X-Patchwork-Id: 11528419 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id B2B6D912 for ; Tue, 5 May 2020 08:35:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A4728206B9 for ; Tue, 5 May 2020 08:35:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728114AbgEEIfW (ORCPT ); Tue, 5 May 2020 04:35:22 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:48750 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725320AbgEEIfW (ORCPT ); Tue, 5 May 2020 04:35:22 -0400 Received: from pps.filterd (m0098394.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 0458XNOJ105030; Tue, 5 May 2020 04:35:21 -0400 Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com with ESMTP id 30twhwtw7p-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 05 May 2020 04:35:21 -0400 Received: from m0098394.ppops.net (m0098394.ppops.net [127.0.0.1]) by pps.reinject (8.16.0.36/8.16.0.36) with SMTP id 0458Z9PF116172; Tue, 5 May 2020 04:35:21 -0400 Received: from ppma04fra.de.ibm.com (6a.4a.5195.ip4.static.sl-reverse.com [149.81.74.106]) by mx0a-001b2d01.pphosted.com with ESMTP id 30twhwtw6p-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 05 May 2020 04:35:21 -0400 Received: from pps.filterd (ppma04fra.de.ibm.com [127.0.0.1]) by ppma04fra.de.ibm.com (8.16.0.27/8.16.0.27) with SMTP id 0458UVQO007078; Tue, 5 May 2020 08:35:19 GMT Received: from b06cxnps4075.portsmouth.uk.ibm.com (d06relay12.portsmouth.uk.ibm.com [9.149.109.197]) by ppma04fra.de.ibm.com with ESMTP id 30s0g62mqn-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 05 May 2020 08:35:18 +0000 Received: from d06av22.portsmouth.uk.ibm.com (d06av22.portsmouth.uk.ibm.com [9.149.105.58]) by b06cxnps4075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 0458ZG9r25166036 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 5 May 2020 08:35:16 GMT Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 3A84A4C04E; Tue, 5 May 2020 08:35:16 +0000 (GMT) Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 32C6F4C046; Tue, 5 May 2020 08:35:16 +0000 (GMT) Received: from tuxmaker.boeblingen.de.ibm.com (unknown [9.152.85.9]) by d06av22.portsmouth.uk.ibm.com (Postfix) with ESMTPS; Tue, 5 May 2020 08:35:16 +0000 (GMT) Received: by tuxmaker.boeblingen.de.ibm.com (Postfix, from userid 25651) id BE122E0605; Tue, 5 May 2020 10:35:15 +0200 (CEST) From: Christian Borntraeger To: Janosch Frank Cc: KVM , Cornelia Huck , Christian Borntraeger , David Hildenbrand , linux-s390 , Qian Cai , Pierre Morel , Tony Krowiak Subject: [PATCH v2] KVM: s390: Remove false WARN_ON_ONCE for the PQAP instruction Date: Tue, 5 May 2020 10:35:15 +0200 Message-Id: <20200505083515.2720-1-borntraeger@de.ibm.com> X-Mailer: git-send-email 2.25.4 MIME-Version: 1.0 X-TM-AS-GCONF: 00 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.138,18.0.676 definitions=2020-05-05_04:2020-05-04,2020-05-05 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 mlxlogscore=999 priorityscore=1501 lowpriorityscore=0 bulkscore=0 spamscore=0 phishscore=0 malwarescore=0 impostorscore=0 suspectscore=0 mlxscore=0 clxscore=1015 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2003020000 definitions=main-2005050069 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org In LPAR we will only get an intercept for FC==3 for the PQAP instruction. Running nested under z/VM can result in other intercepts as well as ECA_APIE is an effective bit: If one hypervisor layer has turned this bit off, the end result will be that we will get intercepts for all function codes. Usually the first one will be a query like PQAP(QCI). So the WARN_ON_ONCE is not right. Let us simply remove it. Cc: Pierre Morel Cc: Tony Krowiak Cc: stable@vger.kernel.org Link: https://lore.kernel.org/kvm/20200505073525.2287-1-borntraeger@de.ibm.com Reported-by: Qian Cai Signed-off-by: Christian Borntraeger Reviewed-by: David Hildenbrand Reviewed-by: Cornelia Huck --- arch/s390/kvm/priv.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/arch/s390/kvm/priv.c b/arch/s390/kvm/priv.c index 69a824f9ef0b..893893642415 100644 --- a/arch/s390/kvm/priv.c +++ b/arch/s390/kvm/priv.c @@ -626,10 +626,12 @@ static int handle_pqap(struct kvm_vcpu *vcpu) * available for the guest are AQIC and TAPQ with the t bit set * since we do not set IC.3 (FIII) we currently will only intercept * the AQIC function code. + * Note: running nested under z/VM can result in intercepts for other + * function codes, e.g. PQAP(QCI). We do not support this and bail out. */ reg0 = vcpu->run->s.regs.gprs[0]; fc = (reg0 >> 24) & 0xff; - if (WARN_ON_ONCE(fc != 0x03)) + if (fc != 0x03) return -EOPNOTSUPP; /* PQAP instruction is allowed for guest kernel only */