From mboxrd@z Thu Jan 1 00:00:00 1970 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 EA362C47088 for ; Fri, 25 Nov 2022 12:43:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229631AbiKYMnN (ORCPT ); Fri, 25 Nov 2022 07:43:13 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44362 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230009AbiKYMnK (ORCPT ); Fri, 25 Nov 2022 07:43:10 -0500 Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AD42D1ADB6; Fri, 25 Nov 2022 04:43:08 -0800 (PST) Received: from pps.filterd (m0098420.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 2APCPqh7012686; Fri, 25 Nov 2022 12:43:08 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : content-transfer-encoding : mime-version; s=pp1; bh=irjOIF8M8yp3sZ3PswIo74jjI9gPXW3VvYUxA64Wrmc=; b=o0YKEX3JUhs2O+bRLyjTbx6clpDYmIMntV9Odimcgz97pLKWoDm5Igtc5WcYB5Td3Vwc W6j2mwBEdgi7fGCLUVVk4rcZjWYaeq/G+7ZcZC4PeN+0t9eXuMO8vWu/8vEzDCCL8Kx+ QejEH5dfAw/jDLd65cBzu1kgpUpb+aCOsCx3YQ+jquBOh/kfiIhxhh1guEMfruC0iQJt pdlqOMivt0yISY08ExhhITLOuLMwxURwCT6fKPYak5T0b7UIKP/7/QmS3YxoqQxPUdRS F/BrA7iPBHDbfONpxrt4bIzcsf3hosdRQYTYGJz6OGRFtdJDXMuiMv3VxHHnspLQZ7uR 6g== Received: from pps.reinject (localhost [127.0.0.1]) by mx0b-001b2d01.pphosted.com (PPS) with ESMTPS id 3m2wq1ga61-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 25 Nov 2022 12:43:07 +0000 Received: from m0098420.ppops.net (m0098420.ppops.net [127.0.0.1]) by pps.reinject (8.17.1.5/8.17.1.5) with ESMTP id 2APCWFGM002595; Fri, 25 Nov 2022 12:43:07 GMT Received: from ppma06ams.nl.ibm.com (66.31.33a9.ip4.static.sl-reverse.com [169.51.49.102]) by mx0b-001b2d01.pphosted.com (PPS) with ESMTPS id 3m2wq1ga5d-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 25 Nov 2022 12:43:07 +0000 Received: from pps.filterd (ppma06ams.nl.ibm.com [127.0.0.1]) by ppma06ams.nl.ibm.com (8.16.1.2/8.16.1.2) with SMTP id 2APCZZIV029884; Fri, 25 Nov 2022 12:43:05 GMT Received: from b06cxnps4075.portsmouth.uk.ibm.com (d06relay12.portsmouth.uk.ibm.com [9.149.109.197]) by ppma06ams.nl.ibm.com with ESMTP id 3kxpdj1mb4-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 25 Nov 2022 12:43:05 +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 2APCh2cL60293538 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 25 Nov 2022 12:43:02 GMT Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 141214C050; Fri, 25 Nov 2022 12:43:02 +0000 (GMT) Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 96B8D4C044; Fri, 25 Nov 2022 12:43:01 +0000 (GMT) Received: from li-9fd7f64c-3205-11b2-a85c-df942b00d78d.ibm.com.com (unknown [9.171.63.115]) by d06av22.portsmouth.uk.ibm.com (Postfix) with ESMTP; Fri, 25 Nov 2022 12:43:01 +0000 (GMT) From: Janosch Frank To: pbonzini@redhat.com Cc: kvm@vger.kernel.org, frankja@linux.ibm.com, david@redhat.com, borntraeger@de.ibm.com, cohuck@redhat.com, linux-s390@vger.kernel.org, imbrenda@linux.ibm.com, Nico Boehr , Steffen Eiden Subject: [GIT PULL 11/15] KVM: s390: pv: avoid export before import if possible Date: Fri, 25 Nov 2022 13:39:43 +0100 Message-Id: <20221125123947.31047-12-frankja@linux.ibm.com> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221125123947.31047-1-frankja@linux.ibm.com> References: <20221125123947.31047-1-frankja@linux.ibm.com> X-TM-AS-GCONF: 00 X-Proofpoint-GUID: ToOC2cojhyUvHnPWTtMWllZ8yiZzeAnZ X-Proofpoint-ORIG-GUID: D1GNRZneW7Old1UBANVyZbRjONFLveyW Content-Transfer-Encoding: 8bit X-Proofpoint-UnRewURL: 0 URL was un-rewritten MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.219,Aquarius:18.0.895,Hydra:6.0.545,FMLib:17.11.122.1 definitions=2022-11-25_04,2022-11-25_01,2022-06-22_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 mlxscore=0 mlxlogscore=999 lowpriorityscore=0 clxscore=1015 spamscore=0 phishscore=0 impostorscore=0 suspectscore=0 priorityscore=1501 adultscore=0 bulkscore=0 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2210170000 definitions=main-2211250098 Precedence: bulk List-ID: X-Mailing-List: linux-s390@vger.kernel.org From: Claudio Imbrenda If the appropriate UV feature bit is set, there is no need to perform an export before import. The misc feature indicates, among other things, that importing a shared page from a different protected VM will automatically also transfer its ownership. Signed-off-by: Claudio Imbrenda Reviewed-by: Nico Boehr Reviewed-by: Janosch Frank Reviewed-by: Steffen Eiden Link: https://lore.kernel.org/r/20221111170632.77622-5-imbrenda@linux.ibm.com Message-Id: <20221111170632.77622-5-imbrenda@linux.ibm.com> Signed-off-by: Janosch Frank --- arch/s390/kernel/uv.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/arch/s390/kernel/uv.c b/arch/s390/kernel/uv.c index f9810d2a267c..9f18a4af9c13 100644 --- a/arch/s390/kernel/uv.c +++ b/arch/s390/kernel/uv.c @@ -255,6 +255,13 @@ static int make_secure_pte(pte_t *ptep, unsigned long addr, */ static bool should_export_before_import(struct uv_cb_header *uvcb, struct mm_struct *mm) { + /* + * The misc feature indicates, among other things, that importing a + * shared page from a different protected VM will automatically also + * transfer its ownership. + */ + if (test_bit_inv(BIT_UV_FEAT_MISC, &uv_info.uv_feature_indications)) + return false; if (uvcb->cmd == UVC_CMD_UNPIN_PAGE_SHARED) return false; return atomic_read(&mm->context.protected_count) > 1; -- 2.38.1