From patchwork Tue Apr 7 11:42:39 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christian Borntraeger X-Patchwork-Id: 11477965 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 114AD1893 for ; Tue, 7 Apr 2020 11:42:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E4C582063A for ; Tue, 7 Apr 2020 11:42:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728179AbgDGLmu (ORCPT ); Tue, 7 Apr 2020 07:42:50 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:33054 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728152AbgDGLmu (ORCPT ); Tue, 7 Apr 2020 07:42:50 -0400 Received: from pps.filterd (m0098396.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 037BYXbe126845 for ; Tue, 7 Apr 2020 07:42:49 -0400 Received: from e06smtp02.uk.ibm.com (e06smtp02.uk.ibm.com [195.75.94.98]) by mx0a-001b2d01.pphosted.com with ESMTP id 306mjdmsnv-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Tue, 07 Apr 2020 07:42:48 -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) Tue, 7 Apr 2020 12:42:25 +0100 Received: from d06av26.portsmouth.uk.ibm.com (d06av26.portsmouth.uk.ibm.com [9.149.105.62]) by b06cxnps4074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 037BggC347841516 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 7 Apr 2020 11:42:42 GMT Received: from d06av26.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 21EAEAE051; Tue, 7 Apr 2020 11:42:42 +0000 (GMT) Received: from d06av26.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 102A5AE053; Tue, 7 Apr 2020 11:42:42 +0000 (GMT) Received: from tuxmaker.boeblingen.de.ibm.com (unknown [9.152.85.9]) by d06av26.portsmouth.uk.ibm.com (Postfix) with ESMTPS; Tue, 7 Apr 2020 11:42:42 +0000 (GMT) Received: by tuxmaker.boeblingen.de.ibm.com (Postfix, from userid 25651) id C71EEE08E5; Tue, 7 Apr 2020 13:42:41 +0200 (CEST) From: Christian Borntraeger To: Paolo Bonzini Cc: KVM , Janosch Frank , David Hildenbrand , Cornelia Huck , linux-s390 , Christian Borntraeger , Claudio Imbrenda Subject: [GIT PULL 2/3] KVM: s390: vsie: Fix delivery of addressing exceptions Date: Tue, 7 Apr 2020 13:42:39 +0200 X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200407114240.156419-1-borntraeger@de.ibm.com> References: <20200407114240.156419-1-borntraeger@de.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 20040711-0008-0000-0000-0000036C1F79 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 20040711-0009-0000-0000-00004A8DB8D8 Message-Id: <20200407114240.156419-3-borntraeger@de.ibm.com> X-Proofpoint-UnRewURL: 0 URL was un-rewritten MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.138,18.0.676 definitions=2020-04-07_03:2020-04-07,2020-04-07 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 adultscore=0 mlxlogscore=999 clxscore=1015 lowpriorityscore=0 mlxscore=0 priorityscore=1501 suspectscore=0 malwarescore=0 phishscore=0 spamscore=0 bulkscore=0 impostorscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2003020000 definitions=main-2004070095 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: David Hildenbrand Whenever we get an -EFAULT, we failed to read in guest 2 physical address space. Such addressing exceptions are reported via a program intercept to the nested hypervisor. We faked the intercept, we have to return to guest 2. Instead, right now we would be returning -EFAULT from the intercept handler, eventually crashing the VM. the correct thing to do is to return 1 as rc == 1 is the internal representation of "we have to go back into g2". Addressing exceptions can only happen if the g2->g3 page tables reference invalid g2 addresses (say, either a table or the final page is not accessible - so something that basically never happens in sane environments. Identified by manual code inspection. Fixes: a3508fbe9dc6 ("KVM: s390: vsie: initial support for nested virtualization") Cc: # v4.8+ Signed-off-by: David Hildenbrand Link: https://lore.kernel.org/r/20200403153050.20569-3-david@redhat.com Reviewed-by: Claudio Imbrenda Reviewed-by: Christian Borntraeger [borntraeger@de.ibm.com: fix patch description] Signed-off-by: Christian Borntraeger --- arch/s390/kvm/vsie.c | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/s390/kvm/vsie.c b/arch/s390/kvm/vsie.c index 076090f9e666..4f6c22d72072 100644 --- a/arch/s390/kvm/vsie.c +++ b/arch/s390/kvm/vsie.c @@ -1202,6 +1202,7 @@ static int vsie_run(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) scb_s->iprcc = PGM_ADDRESSING; scb_s->pgmilc = 4; scb_s->gpsw.addr = __rewind_psw(scb_s->gpsw, 4); + rc = 1; } return rc; }