From patchwork Mon Jul 25 12:09:12 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jan Beulich X-Patchwork-Id: 12927998 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 lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id AA7FAC43334 for ; Mon, 25 Jul 2022 12:09:30 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.374544.606605 (Exim 4.92) (envelope-from ) id 1oFwti-0006ME-Rd; Mon, 25 Jul 2022 12:09:18 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 374544.606605; Mon, 25 Jul 2022 12:09:18 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1oFwti-0006M5-Om; Mon, 25 Jul 2022 12:09:18 +0000 Received: by outflank-mailman (input) for mailman id 374544; Mon, 25 Jul 2022 12:09:17 +0000 Received: from se1-gles-flk1-in.inumbo.com ([94.247.172.50] helo=se1-gles-flk1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1oFwth-0006Lv-Jy for xen-devel@lists.xenproject.org; Mon, 25 Jul 2022 12:09:17 +0000 Received: from EUR04-HE1-obe.outbound.protection.outlook.com (mail-eopbgr70050.outbound.protection.outlook.com [40.107.7.50]) by se1-gles-flk1.inumbo.com (Halon) with ESMTPS id 9a36fdcc-0c12-11ed-924f-1f966e50362f; Mon, 25 Jul 2022 14:09:15 +0200 (CEST) Received: from VE1PR04MB6560.eurprd04.prod.outlook.com (2603:10a6:803:122::25) by AM5PR0401MB2434.eurprd04.prod.outlook.com (2603:10a6:203:35::15) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.5458.24; Mon, 25 Jul 2022 12:09:14 +0000 Received: from VE1PR04MB6560.eurprd04.prod.outlook.com ([fe80::d4c4:d01d:5d39:920c]) by VE1PR04MB6560.eurprd04.prod.outlook.com ([fe80::d4c4:d01d:5d39:920c%7]) with mapi id 15.20.5458.019; Mon, 25 Jul 2022 12:09:14 +0000 X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 9a36fdcc-0c12-11ed-924f-1f966e50362f ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=Ohx1BLH9T55WAC6EnItWbmBSSSvAKIY7vRT3PYfFShYfvGXingPhyAfVFfYwNesEyQ+iplQs5C1ysAzIQkVA9VNM4EA2NprJE3ZylnxC3VBdyhBlC4LKbeQ2KA6K496V4a6flMF6Yus2J0GTqh2HeQhW44PYxddsrhlLXVj19kfU6/qtWB7biSgp3LNjQv3CfeNcW4O1RTjukWRdoNXDyxlwID73Snp/Hymgi6pxCjvHo1EMuPq33lKNEhhm8oldLSQ/KskykXfnIjle7kgJdF73kv7dtLp+OUUAMjSbCpmC7K8uohpOTQ/kWSl0FsksaZoknu6YCc8ESBVFF9kzIw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=1yXpgIEPCLYefS8RgPyuvc9ydQjRfy2PsDfZ9Qamkm0=; b=hEpVXk3P+TAndDrk1rIUcwEW1+ChCtznmLS9bTFzbU5yWo3JZln2lFPCjwmlkhZ/4kwgsZ9/+ExQaVGeIWGDfINSoF+AZZ8eVv6gSkfQezyDhqY+EDssuRY5L0Tl4ydBaIkMEjmAN8nJOpuzAqnn8Nt+Sf9riHmXeD/1C15u+zHfczA3YrHXvJZx0eGXmEUVrmQUxxz8sWQ+qfRa2Eb4antNAlo0sW82PPQz4czpWo9IPNwCBE3J9TdF6z8RVG/IPWdDd2QdB0VJU+LN+znupgNzQGv4NQZePxPZM2B+ciWAUmpt5X8J25Uv2v24AnOqZafKmVBGGO4gv1PzEU5EKQ== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=suse.com; dmarc=pass action=none header.from=suse.com; dkim=pass header.d=suse.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=selector1; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=1yXpgIEPCLYefS8RgPyuvc9ydQjRfy2PsDfZ9Qamkm0=; b=X7o9ssrAsyK1uqv00ytPYMRv+yXVyOAb0zLodItaf0aNNXqyUyh/EP7MGm65u3YUGjokB4p4CONLoMlBj2dz7pp87OdAVh1X5L6FahylNdIIBni1DslVixev8d9ih1f53tfoGQqH/lsms0a+KTn8uTVru0YkQnh6CKWzuQpl1NWQbcH6HNjivr5QBmmW3lhBf/1CWbVlgUqpw0hz1QqHOss+YTeWzZHmJSOEeYNeY/8mFZqBaCrzPYr7Sek8QBvQRw+1w3LSVECwZKUjpUSs/HEUDtswGwsRnjrBLGxTeZXOWjQFr101jAziZyC1Lacp0yrCKJG3QhaQP599alQUYQ== Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=suse.com; Message-ID: <3327586c-1489-4af9-0fa2-29f48d957954@suse.com> Date: Mon, 25 Jul 2022 14:09:12 +0200 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.11.0 Content-Language: en-US To: "xen-devel@lists.xenproject.org" Cc: Andrew Cooper , Wei Liu , =?utf-8?q?Roger_Pau_Monn=C3=A9?= From: Jan Beulich Subject: [PATCH] x86: limit issuing of IBPB during context switch X-ClientProxiedBy: FR0P281CA0062.DEUP281.PROD.OUTLOOK.COM (2603:10a6:d10:49::23) To VE1PR04MB6560.eurprd04.prod.outlook.com (2603:10a6:803:122::25) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-Correlation-Id: 3dafc363-c6eb-4e01-b5e7-08da6e367d7b X-MS-TrafficTypeDiagnostic: AM5PR0401MB2434:EE_ X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: 9IHe25fSq52+X3qntK22Oz+oinjTB/vvKMN4Y1fd84JwL3TXh2cdfv5aMQDENl6iugWIUyx6yBunzO+iV1KyX2tivWdm+k/FdCgWtmo+PyzSGMVFW9Qodg8jq6YcMqpLsgySo9ksqS1JuaPFfG6PLCVoJ/ir2gnhaf3ziG/DmIte2IY8MfaubSoT03RqvBq0lOQMM3ay+AVbyDLc6UcejC+SybCRzYKRC00TfHhN98a/pAJd8T8ue97weVZka4CgYt0fhjoBZDL6F+Cu5tQkco8nz+N4qkVH0nFAC6M5ryDPwzw1xvG8ADEfykGML50dOyvCworBD/2OWPpqfBiQowh0jdHgs14k1G2tspjJDPcp08UNNye20qipJhUlyIuSuFlhdjqHiCYZSkwR3Nf17vi316H9SAM/5CKIiZZIzDLQ7DVjriPIICMYvwf/fZ5EbF7fSSaT0H2kFOVA0/Pt8vf2N3JJX8UWo/EvBDE1lCau+KuzbWwQf5P11uBz0Y6oP9jCYocBN3Z5zOayWLoMfj1+W2VAya5xjmkiUhCfEyJIEnxo+UOpGoHQFcM6icms5gwUqE7dVYxmvflQqSgpzJP7DYgv3LwwCLFW/3bW4BCBBGq6xC+3+BiQ/AgeghpGwq4FgHtNpREj+wttf4+IU5Gm2ZM/T7x6VZTeI2u4VGptGbsCFUdDwcyuTaNIldqfQf0BaiIM45WJVJfc/JQEDnZJt9IjLNEifx2FG7gEXxZjB1IxyyKUTvXRn4DP1VLttZR8Zoe9Nk9edanTxp8Y63HIEKopl7irHoLvHCVU/JjPQtMMRY1ah+qbtaRQWfnuRfp+eA3A1pMXX4LQdPS+HQ== X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:VE1PR04MB6560.eurprd04.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230016)(396003)(366004)(39860400002)(346002)(376002)(136003)(186003)(36756003)(2616005)(66946007)(54906003)(6916009)(66556008)(4326008)(6506007)(8676002)(31686004)(66476007)(6512007)(41300700001)(26005)(2906002)(38100700002)(31696002)(86362001)(5660300002)(4744005)(8936002)(316002)(6486002)(478600001)(43740500002)(45980500001);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?q?NifiTA8/lwHHInzNnFMVatoEHHq+?= =?utf-8?q?yFOTy5P7txZ72dDt4gFpMz2T0i/3xCaB30/dBpB0hW+XLZB/cJi3g1Zae0JEqr4CH?= =?utf-8?q?jt4X0oYKAa3Jj3qDnspsQM/atj81GFMG4T6Tc5gboravBRP7IYk6qgh6BWMNGCbNq?= =?utf-8?q?Nz+YVeujigN9vU2wwjA7riG+xNMs6CZ4O03TqQcc4+6Wfk2uIrgyzzLOYnV98aMMj?= =?utf-8?q?7xS6ppHE6ym9cn6WVK06nJ0gk4MJ8J8KqKCRDKtSTH8xpUBeuqbg9lcwFw9BXOlaV?= =?utf-8?q?V69dVgYVnO2VSH1fITGAzmy0x+YcwHBUmj5N2Tu157a3cjmhqwM/QAwtOF5dJNRAB?= =?utf-8?q?iiZ+UnJvzS80lgn12tj+ILRgpAeztYGmJ5t6RquybA8XP+9I8c/b01v/dmTASnPly?= =?utf-8?q?bOwMBzr6mAkk2d3BwptCaD0gdH1PQj1X0XPDg6/MI+7yV/fBEsi/wX6yAuVV/aeP8?= =?utf-8?q?70gmAoOjy/JeAJp1BtrPlPZMTfwsMuXIAumK7BQq9vcYnUBhaDmrDNSrERa4q7C2r?= =?utf-8?q?7BhiNzy1hFbtZUe+ufpEpiP2yeAxuLXhTX+X75cOHcjxo5LjesmcO7iDq8NSU41Fj?= =?utf-8?q?d+1CDUMNKqAxrSCBYfEOANkQXP9H+ss0/1s9QonEyn0B982783BYgzL8WqUWsxy06?= =?utf-8?q?bmYEYvO9xeCKappHemOfdx/Qn74GOKaN8K1RQIlIwqa15k/MvsWLxpHnCWsYATt7M?= =?utf-8?q?0LJopL/e8bpulkCEioRLQi3iP0K6MeKt0ZfZV32KtmubVwyerBcKp5nMbvcuXpICQ?= =?utf-8?q?9RoGgZxCkhVWltxX9bApzwOCW0KEAj1C1Hsb0qo8y4fUpxoejNtlGB49QE1VaNyOy?= =?utf-8?q?Jmda2P1p1S8R1MGhis1fyz3We3l8vXXcPZMwbjUzjjf+6aK0X8exwiF/d05kML6e5?= =?utf-8?q?en2VL6rYuRe5J3oW1hrzWNOV/nG2Z7Bb7iRIfne/YqBXXArJ7pntTIXlpA8+3LRBe?= =?utf-8?q?P5FAMbds7T9qWaNN8LsfckJcQiDxwf2P372wrJAmXwa2hpFzCnTMpnYn5xsdLAxVC?= =?utf-8?q?JOi/yEdYsPB0tiHtFRCxIN+SHHGQ2l/AUZLyVcMpEexnb6L7aWXh+vCCYmjhRqElb?= =?utf-8?q?kN8ejx1pcH+sRbrv1bX9hu2F2sCSeDsAPkR/4jJRWpg1P+iBOuzNvC0KR7xMuZg0M?= =?utf-8?q?JqNrdzdBgZbjmiCTnv3wbifvBxXCBIq18XyKD8MGpTdEccAvUcgulAKHxMQEdoVM9?= =?utf-8?q?u9Q6Sq6X+4PVipx7OZDTnrLEx2NoSZhSAMR+iZqyoNkXfopva2SP5k4jSmA75tfjj?= =?utf-8?q?kmGEBwWONgv4uYqtPBNSdD4T3i6ouGseP9rCL+WCuUhYDgqVIAT02lnPJ2v95tebo?= =?utf-8?q?TiE9WJ9FZHLbpUIM9DizCz98NZ1VJTMZgcJkzqZHXrdpur1KfJ/yp5a4ehYP10SpD?= =?utf-8?q?16cf5IClL6nNwAbc276nQ8iBpHPQrL5x6GibgGGIccAV2fUdFJtEgPATgaL1LyFL3?= =?utf-8?q?ghTXq0g6Z8yc6okqbqRPPzD9B+7no3WT12pBlSM94ALkxCYO+/82rj6IJb5YTU/rs?= =?utf-8?q?rxbGEgijf/JO?= X-OriginatorOrg: suse.com X-MS-Exchange-CrossTenant-Network-Message-Id: 3dafc363-c6eb-4e01-b5e7-08da6e367d7b X-MS-Exchange-CrossTenant-AuthSource: VE1PR04MB6560.eurprd04.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 25 Jul 2022 12:09:14.0613 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: f7a17af6-1c5c-4a36-aa8b-f5be247aa4ba X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: YdykzJ86Bdydfa4rwsWsnrNZi5rgvp9flFtFAV5dvrEvAn8ZWIcfQekG7vYIo72CNki6sVOJxAW9fDSFMSfsrg== X-MS-Exchange-Transport-CrossTenantHeadersStamped: AM5PR0401MB2434 When the outgoing vCPU had IBPB issued upon entering Xen there's no need for a 2nd barrier during context switch. Signed-off-by: Jan Beulich --- a/xen/arch/x86/domain.c +++ b/xen/arch/x86/domain.c @@ -2098,7 +2098,8 @@ void context_switch(struct vcpu *prev, s ctxt_switch_levelling(next); - if ( opt_ibpb_ctxt_switch && !is_idle_domain(nextd) ) + if ( opt_ibpb_ctxt_switch && !is_idle_domain(nextd) && + !(prevd->arch.spec_ctrl_flags & SCF_entry_ibpb) ) { static DEFINE_PER_CPU(unsigned int, last); unsigned int *last_id = &this_cpu(last);