From patchwork Wed Mar 30 12:25:53 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Claudio Imbrenda X-Patchwork-Id: 12795763 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C3437C433FE for ; Wed, 30 Mar 2022 12:37:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345044AbiC3Mj1 (ORCPT ); Wed, 30 Mar 2022 08:39:27 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46170 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344383AbiC3Mh2 (ORCPT ); Wed, 30 Mar 2022 08:37:28 -0400 Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com [148.163.156.1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B8CEE90FDE; Wed, 30 Mar 2022 05:26:21 -0700 (PDT) Received: from pps.filterd (m0098396.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.1.2/8.16.1.2) with SMTP id 22UBt3kS023265; 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Wed, 30 Mar 2022 12:26:14 +0000 (GMT) Received: from localhost.localdomain (unknown [9.145.13.95]) by d06av25.portsmouth.uk.ibm.com (Postfix) with ESMTP; Wed, 30 Mar 2022 12:26:14 +0000 (GMT) From: Claudio Imbrenda To: kvm@vger.kernel.org Cc: borntraeger@de.ibm.com, frankja@linux.ibm.com, thuth@redhat.com, pasic@linux.ibm.com, david@redhat.com, linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, scgl@linux.ibm.com, mimu@linux.ibm.com, nrb@linux.ibm.com Subject: [PATCH v9 06/18] KVM: s390: pv: add export before import Date: Wed, 30 Mar 2022 14:25:53 +0200 Message-Id: <20220330122605.247613-7-imbrenda@linux.ibm.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220330122605.247613-1-imbrenda@linux.ibm.com> References: <20220330122605.247613-1-imbrenda@linux.ibm.com> MIME-Version: 1.0 X-TM-AS-GCONF: 00 X-Proofpoint-GUID: gXfqcyKsWvIY-rVXczVJefZCFHB-FqPH X-Proofpoint-ORIG-GUID: Gpz6IQZB2U2gh3mYuP3AaMQhglV5nKKI X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.850,Hydra:6.0.425,FMLib:17.11.64.514 definitions=2022-03-30_04,2022-03-30_01,2022-02-23_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 phishscore=0 mlxlogscore=999 mlxscore=0 clxscore=1015 impostorscore=0 bulkscore=0 priorityscore=1501 lowpriorityscore=0 malwarescore=0 suspectscore=0 spamscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2202240000 definitions=main-2203300062 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Due to upcoming changes, it will be possible to temporarily have multiple protected VMs in the same address space, although only one will be actually active. In that scenario, it is necessary to perform an export of every page that is to be imported, since the hardware does not allow a page belonging to a protected guest to be imported into a different protected guest. This also applies to pages that are shared, and thus accessible by the host. Signed-off-by: Claudio Imbrenda Reviewed-by: Janosch Frank --- arch/s390/kernel/uv.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/arch/s390/kernel/uv.c b/arch/s390/kernel/uv.c index 2754471cc789..e358b8bd864b 100644 --- a/arch/s390/kernel/uv.c +++ b/arch/s390/kernel/uv.c @@ -234,6 +234,12 @@ static int make_secure_pte(pte_t *ptep, unsigned long addr, return uvcb->rc == 0x10a ? -ENXIO : -EINVAL; } +static bool should_export_before_import(struct uv_cb_header *uvcb, struct mm_struct *mm) +{ + return uvcb->cmd != UVC_CMD_UNPIN_PAGE_SHARED && + atomic_read(&mm->context.protected_count) > 1; +} + /* * Requests the Ultravisor to make a page accessible to a guest. * If it's brought in the first time, it will be cleared. If @@ -277,6 +283,8 @@ int gmap_make_secure(struct gmap *gmap, unsigned long gaddr, void *uvcb) lock_page(page); ptep = get_locked_pte(gmap->mm, uaddr, &ptelock); + if (should_export_before_import(uvcb, gmap->mm)) + uv_convert_from_secure(page_to_phys(page)); rc = make_secure_pte(ptep, uaddr, page, uvcb); pte_unmap_unlock(ptep, ptelock); unlock_page(page);