From patchwork Fri Feb 14 22:26:28 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christian Borntraeger X-Patchwork-Id: 11383351 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 4FF85191F for ; Fri, 14 Feb 2020 22:27:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 38242222C4 for ; Fri, 14 Feb 2020 22:27:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727898AbgBNW1U (ORCPT ); Fri, 14 Feb 2020 17:27:20 -0500 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:43310 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727860AbgBNW1T (ORCPT ); Fri, 14 Feb 2020 17:27:19 -0500 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 01EMQtsq065815; Fri, 14 Feb 2020 17:27:18 -0500 Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com with ESMTP id 2y57au0nxn-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 14 Feb 2020 17:27:18 -0500 Received: from m0098396.ppops.net (m0098396.ppops.net [127.0.0.1]) by pps.reinject (8.16.0.36/8.16.0.36) with SMTP id 01EMRIdG067472; Fri, 14 Feb 2020 17:27:18 -0500 Received: from ppma02wdc.us.ibm.com (aa.5b.37a9.ip4.static.sl-reverse.com [169.55.91.170]) by mx0a-001b2d01.pphosted.com with ESMTP id 2y57au0nxa-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 14 Feb 2020 17:27:18 -0500 Received: from pps.filterd (ppma02wdc.us.ibm.com [127.0.0.1]) by ppma02wdc.us.ibm.com (8.16.0.27/8.16.0.27) with SMTP id 01EMRClx013698; Fri, 14 Feb 2020 22:27:17 GMT Received: from b03cxnp08025.gho.boulder.ibm.com (b03cxnp08025.gho.boulder.ibm.com [9.17.130.17]) by ppma02wdc.us.ibm.com with ESMTP id 2y5bc09wr2-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 14 Feb 2020 22:27:17 +0000 Received: from b03ledav002.gho.boulder.ibm.com (b03ledav002.gho.boulder.ibm.com [9.17.130.233]) by b03cxnp08025.gho.boulder.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 01EMRDYQ48431456 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 14 Feb 2020 22:27:13 GMT Received: from b03ledav002.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 41C35136091; Fri, 14 Feb 2020 22:27:13 +0000 (GMT) Received: from b03ledav002.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 860F0136096; Fri, 14 Feb 2020 22:27:12 +0000 (GMT) Received: from localhost.localdomain (unknown [9.114.17.106]) by b03ledav002.gho.boulder.ibm.com (Postfix) with ESMTP; Fri, 14 Feb 2020 22:27:12 +0000 (GMT) From: Christian Borntraeger To: Christian Borntraeger , Janosch Frank Cc: KVM , Cornelia Huck , David Hildenbrand , Thomas Huth , Ulrich Weigand , Claudio Imbrenda , linux-s390 , Michael Mueller , Vasily Gorbik Subject: [PATCH v2 12/42] KVM: s390/mm: Make pages accessible before destroying the guest Date: Fri, 14 Feb 2020 17:26:28 -0500 Message-Id: <20200214222658.12946-13-borntraeger@de.ibm.com> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200214222658.12946-1-borntraeger@de.ibm.com> References: <20200214222658.12946-1-borntraeger@de.ibm.com> MIME-Version: 1.0 X-TM-AS-GCONF: 00 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.138,18.0.572 definitions=2020-02-14_08:2020-02-14,2020-02-14 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 bulkscore=0 adultscore=0 malwarescore=0 priorityscore=1501 suspectscore=0 mlxscore=0 spamscore=0 phishscore=0 lowpriorityscore=0 mlxlogscore=845 impostorscore=0 clxscore=1015 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2001150001 definitions=main-2002140165 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Before we destroy the secure configuration, we better make all pages accessible again. This also happens during reboot, where we reboot into a non-secure guest that then can go again into secure mode. As this "new" secure guest will have a new ID we cannot reuse the old page state. Signed-off-by: Christian Borntraeger Reviewed-by: Thomas Huth Reviewed-by: Cornelia Huck Reviewed-by: David Hildenbrand --- arch/s390/include/asm/gmap.h | 1 + arch/s390/kvm/pv.c | 2 ++ arch/s390/mm/gmap.c | 35 +++++++++++++++++++++++++++++++++++ 3 files changed, 38 insertions(+) diff --git a/arch/s390/include/asm/gmap.h b/arch/s390/include/asm/gmap.h index 6f9ff7a69fa2..a816fb4734b8 100644 --- a/arch/s390/include/asm/gmap.h +++ b/arch/s390/include/asm/gmap.h @@ -149,4 +149,5 @@ int gmap_mprotect_notify(struct gmap *, unsigned long start, void gmap_sync_dirty_log_pmd(struct gmap *gmap, unsigned long dirty_bitmap[4], unsigned long gaddr, unsigned long vmaddr); int gmap_mark_unmergeable(void); +void s390_reset_acc(struct mm_struct *mm); #endif /* _ASM_S390_GMAP_H */ diff --git a/arch/s390/kvm/pv.c b/arch/s390/kvm/pv.c index bf00cde1ead8..09573e36c329 100644 --- a/arch/s390/kvm/pv.c +++ b/arch/s390/kvm/pv.c @@ -66,6 +66,8 @@ int kvm_s390_pv_destroy_vm(struct kvm *kvm, u16 *rc, u16 *rrc) { int cc; + /* make all pages accessible before destroying the guest */ + s390_reset_acc(kvm->mm); cc = uv_cmd_nodata(kvm_s390_pv_handle(kvm), UVC_CMD_DESTROY_SEC_CONF, rc, rrc); WRITE_ONCE(kvm->arch.gmap->guest_handle, 0); diff --git a/arch/s390/mm/gmap.c b/arch/s390/mm/gmap.c index 7291452fe5f0..27926a06df32 100644 --- a/arch/s390/mm/gmap.c +++ b/arch/s390/mm/gmap.c @@ -2650,3 +2650,38 @@ void s390_reset_cmma(struct mm_struct *mm) up_write(&mm->mmap_sem); } EXPORT_SYMBOL_GPL(s390_reset_cmma); + +/* + * make inaccessible pages accessible again + */ +static int __s390_reset_acc(pte_t *ptep, unsigned long addr, + unsigned long next, struct mm_walk *walk) +{ + pte_t pte = READ_ONCE(*ptep); + + if (pte_present(pte)) + WARN_ON_ONCE(uv_convert_from_secure(pte_val(pte) & PAGE_MASK)); + return 0; +} + +static const struct mm_walk_ops reset_acc_walk_ops = { + .pte_entry = __s390_reset_acc, +}; + +#include +void s390_reset_acc(struct mm_struct *mm) +{ + /* + * we might be called during + * reset: we walk the pages and clear + * close of all kvm file descriptors: we walk the pages and clear + * exit of process on fd closure: vma already gone, do nothing + */ + if (!mmget_not_zero(mm)) + return; + down_read(&mm->mmap_sem); + walk_page_range(mm, 0, TASK_SIZE, &reset_acc_walk_ops, NULL); + up_read(&mm->mmap_sem); + mmput(mm); +} +EXPORT_SYMBOL_GPL(s390_reset_acc);