From patchwork Fri Jun 3 06:56:37 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Claudio Imbrenda X-Patchwork-Id: 12868681 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 76F1BC43334 for ; Fri, 3 Jun 2022 06:58:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241990AbiFCG57 (ORCPT ); Fri, 3 Jun 2022 02:57:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33636 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241810AbiFCG5F (ORCPT ); Fri, 3 Jun 2022 02:57:05 -0400 Received: from mx0b-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 89D8D1108; Thu, 2 Jun 2022 23:56:58 -0700 (PDT) Received: from pps.filterd (m0127361.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.17.1.5/8.17.1.5) with ESMTP id 2536hqJ7031311; 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Fri, 3 Jun 2022 06:56:50 +0000 (GMT) Received: from p-imbrenda.boeblingen.de.ibm.com (unknown [9.152.224.40]) by d06av24.portsmouth.uk.ibm.com (Postfix) with ESMTP; Fri, 3 Jun 2022 06:56:50 +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 v11 11/19] s390/mm: KVM: pv: when tearing down, try to destroy protected pages Date: Fri, 3 Jun 2022 08:56:37 +0200 Message-Id: <20220603065645.10019-12-imbrenda@linux.ibm.com> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220603065645.10019-1-imbrenda@linux.ibm.com> References: <20220603065645.10019-1-imbrenda@linux.ibm.com> MIME-Version: 1.0 X-TM-AS-GCONF: 00 X-Proofpoint-ORIG-GUID: cp_swF1N08g-gO1BeF3q4fCItdgS-Xpk X-Proofpoint-GUID: Jt0sJL2iXNP5Iptr1oscGA5zCOA-1Vxa X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.874,Hydra:6.0.517,FMLib:17.11.64.514 definitions=2022-06-03_02,2022-06-02_01,2022-02-23_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 impostorscore=0 phishscore=0 adultscore=0 clxscore=1015 mlxscore=0 spamscore=0 malwarescore=0 priorityscore=1501 suspectscore=0 mlxlogscore=861 bulkscore=0 lowpriorityscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2204290000 definitions=main-2206030027 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org When ptep_get_and_clear_full is called for a mm teardown, we will now attempt to destroy the secure pages. This will be faster than export. In case it was not a teardown, or if for some reason the destroy page UVC failed, we try with an export page, like before. Signed-off-by: Claudio Imbrenda Acked-by: Janosch Frank Reviewed-by: Nico Boehr --- arch/s390/include/asm/pgtable.h | 19 ++++++++++++++++--- 1 file changed, 16 insertions(+), 3 deletions(-) diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h index f16403ba81ec..cf81acf3879c 100644 --- a/arch/s390/include/asm/pgtable.h +++ b/arch/s390/include/asm/pgtable.h @@ -1182,9 +1182,22 @@ static inline pte_t ptep_get_and_clear_full(struct mm_struct *mm, } else { res = ptep_xchg_lazy(mm, addr, ptep, __pte(_PAGE_INVALID)); } - /* At this point the reference through the mapping is still present */ - if (mm_is_protected(mm) && pte_present(res)) - uv_convert_owned_from_secure(pte_val(res) & PAGE_MASK); + /* Nothing to do */ + if (!mm_is_protected(mm) || !pte_present(res)) + return res; + /* + * At this point the reference through the mapping is still present. + * The notifier should have destroyed all protected vCPUs at this + * point, so the destroy should be successful. + */ + if (full && !uv_destroy_owned_page(pte_val(res) & PAGE_MASK)) + return res; + /* + * If something went wrong and the page could not be destroyed, or + * if this is not a mm teardown, the slower export is used as + * fallback instead. + */ + uv_convert_owned_from_secure(pte_val(res) & PAGE_MASK); return res; }