From nobody Fri Oct 31 04:31:53 2025 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org; arc=pass (i=1 dmarc=pass fromdomain=amd.com); dmarc=pass(p=quarantine dis=none) header.from=amd.com ARC-Seal: i=2; a=rsa-sha256; t=1751933268; cv=pass; d=zohomail.com; s=zohoarc; b=VChIfvw3HBaCqG3qJnlRyno9np4whRoF0d4uIyyLjQ4zYVRxX8eBD3oMmwGHbx28AyoTUOJ434wYgYvDlHEg7ZEtEyrXOJQX9Ir/4z5HaeqT4VrnK+7SBPhCELVpnk27Kp8Gnf/3rGM6HtrPT8+kR/Mz2QWH0/l4cGZj0UCfKgI= ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1751933268; h=Content-Type:Content-Transfer-Encoding:Cc:Cc:Date:Date:From:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:Subject:To:To:Message-Id:Reply-To; bh=ZQgClbWGpr0ReiNMGJQkgrRBR0Oeh+B5V1gh+NMd/0c=; b=fF5wCQyxkDm5+lGLKEIxk78LsSu3Q2UftQqSohIVLfcBF9CFKckN5vSt/JFw8KF3fTMzrCwHno4+sIS/U9VIIrUIh6c6KRIGLJPwjDZnHpnqfNZpJ12DF1Xu2ow9IUKHblcdmql01pUVTnmQQVdOMdcfivStzU/ZH9Uw5fa1viI= ARC-Authentication-Results: i=2; mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org; arc=pass (i=1 dmarc=pass fromdomain=amd.com); dmarc=pass header.from= (p=quarantine dis=none) Return-Path: Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) by mx.zohomail.com with SMTPS id 1751933268232518.6863252417046; Mon, 7 Jul 2025 17:07:48 -0700 (PDT) Received: from list by lists.xenproject.org with outflank-mailman.1035888.1408302 (Exim 4.92) (envelope-from ) id 1uYvs2-0000Q2-9o; Tue, 08 Jul 2025 00:07:38 +0000 Received: by outflank-mailman (output) from mailman id 1035888.1408302; Tue, 08 Jul 2025 00:07:38 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1uYvs2-0000Pv-6r; Tue, 08 Jul 2025 00:07:38 +0000 Received: by outflank-mailman (input) for mailman id 1035888; Tue, 08 Jul 2025 00:07:36 +0000 Received: from se1-gles-sth1-in.inumbo.com ([159.253.27.254] helo=se1-gles-sth1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1uYvs0-0008Ok-Og for xen-devel@lists.xenproject.org; Tue, 08 Jul 2025 00:07:36 +0000 Received: from NAM12-BN8-obe.outbound.protection.outlook.com (mail-bn8nam12on2060c.outbound.protection.outlook.com [2a01:111:f403:2418::60c]) by se1-gles-sth1.inumbo.com (Halon) with ESMTPS id 8cd8c27e-5b8f-11f0-a316-13f23c93f187; Tue, 08 Jul 2025 02:07:36 +0200 (CEST) Received: from BN0PR04CA0007.namprd04.prod.outlook.com (2603:10b6:408:ee::12) by LV3PR12MB9265.namprd12.prod.outlook.com (2603:10b6:408:215::14) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.8901.22; Tue, 8 Jul 2025 00:07:32 +0000 Received: from BN3PEPF0000B374.namprd21.prod.outlook.com (2603:10b6:408:ee:cafe::b1) by BN0PR04CA0007.outlook.office365.com (2603:10b6:408:ee::12) with Microsoft SMTP Server (version=TLS1_3, cipher=TLS_AES_256_GCM_SHA384) id 15.20.8901.27 via Frontend Transport; Tue, 8 Jul 2025 00:07:32 +0000 Received: from SATLEXMB04.amd.com (165.204.84.17) by BN3PEPF0000B374.mail.protection.outlook.com (10.167.243.171) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.20.8943.1 via Frontend Transport; Tue, 8 Jul 2025 00:07:31 +0000 Received: from SATLEXMB03.amd.com (10.181.40.144) by SATLEXMB04.amd.com (10.181.40.145) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.39; Mon, 7 Jul 2025 19:07:31 -0500 Received: from SATLEXMB04.amd.com (10.180.168.240) by SATLEXMB03.amd.com (10.181.40.144) with Microsoft SMTP Server id 15.1.2507.39 via Frontend Transport; Mon, 7 Jul 2025 19:07:30 -0500 X-Outflank-Mailman: Message body and most headers restored to incoming version 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: 8cd8c27e-5b8f-11f0-a316-13f23c93f187 ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=gHiStk4PWORhutOfSpL0C392e9LoSpLYaY3/x1D0ZjvjM+9Id/3KVkuoe3/hodWlIXw9l9vWALi/LAO4+lLJzfHNREzDQ3y85CIAjApVgtJpPBWhN6KX3wcOXWdlcKKxPF6E7hygbBR+jz26q01roD5wuXw5lXPbdOIAyqBsOkAZm2Bv7JOflIad8qeB01q8X9PZAOiZXOstGwPmfHJCHonNUrA6Ec2zpLjJJKO32Td+onMhOzZMog+ZVIAz5jkYvp2E/90bhuXPM9dxVJ8fzOQ0zOZDxwIEOnklCdwx7t4wsnUmjXc74AsNiHM26JxvQKcKKaGPnnGbBWoJ4VD5bg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector10001; 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=ZQgClbWGpr0ReiNMGJQkgrRBR0Oeh+B5V1gh+NMd/0c=; b=ja0rIqwLda4cQq1mdroEMO/jQv8msZnk2mKQKtkxPvYpWcVyRZdhu6FnjLXvbQW0gnvzQoefWD+Z0BJOfC7z8FxaLff0sbLJIGGwui5X++V0kGjjbVbI0KWuqBCm9+rdAX2phWK2g6OjE1b45atRxYyFE0Bzx0JGJJRl/Ub/J17nlRevEiEh46vXJ4AjLMUOeE5oYG+N2j6n2Lv2dsbL1mLFYXzsYbjfTZu3dsWGzWeHYve3TzI1PlmD5tITR6aBMu3CtRyB3ytA1FEKeEY3Tcqs4vw71B1N61Bs3YLbm8jUO3qCfapbnxUS7GG9pp/Ah/qcdihQQ5pgO2caWaL+gA== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass (sender ip is 165.204.84.17) smtp.rcpttodomain=lists.xenproject.org smtp.mailfrom=amd.com; dmarc=pass (p=quarantine sp=quarantine pct=100) action=none header.from=amd.com; dkim=none (message not signed); arc=none (0) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amd.com; s=selector1; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=ZQgClbWGpr0ReiNMGJQkgrRBR0Oeh+B5V1gh+NMd/0c=; b=KJdrVwu9MumK2z+NJEIQFj53VmtDpRxNJHIy8iadm+7IPSKh3te7f116itO3M9pJw6SL4a3xtG3Mkq14su2XLG+C+HomNKc2B1CjbaySXO8RKsZrUQiGZ4yA3Y6ZORb+Bfg1we/y8CpXfCJPQRaK/rJrOpgub50b6elKW1W/upo= X-MS-Exchange-Authentication-Results: spf=pass (sender IP is 165.204.84.17) smtp.mailfrom=amd.com; dkim=none (message not signed) header.d=none;dmarc=pass action=none header.from=amd.com; Received-SPF: pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) client-ip=192.237.175.120; envelope-from=xen-devel-bounces@lists.xenproject.org; helo=lists.xenproject.org; Received-SPF: Pass (protection.outlook.com: domain of amd.com designates 165.204.84.17 as permitted sender) receiver=protection.outlook.com; client-ip=165.204.84.17; helo=SATLEXMB04.amd.com; pr=C From: Stefano Stabellini To: CC: , , , , , , Subject: [PATCH 1/2] xen/x86: don't send IPI to sync TSC when it is reliable Date: Mon, 7 Jul 2025 17:07:11 -0700 Message-ID: <20250708000712.2731666-1-stefano.stabellini@amd.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Received-SPF: None (SATLEXMB04.amd.com: stefano.stabellini@amd.com does not designate permitted sender hosts) X-EOPAttributedMessage: 0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: BN3PEPF0000B374:EE_|LV3PR12MB9265:EE_ X-MS-Office365-Filtering-Correlation-Id: 587f837e-7313-475c-5a4d-08ddbdb36f44 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|376014|82310400026|36860700013|1800799024; X-Microsoft-Antispam-Message-Info: =?us-ascii?Q?czYLjlllCruUXCjRFl0vYmPUjCJlr7kYMokO8VOzzubM48TK9PeA2fantpBB?= =?us-ascii?Q?bfJgzO4yTDKT3iUIHLdALbX5EO5oWjP1/nzWlk029qnPyD48HE4Z6ZrLBCls?= =?us-ascii?Q?hlUSZKBBMJNHm0h6tZOMudBY2jYOLB/0T1Da/9LRNRzkmuDo2R4mpPscJzxd?= =?us-ascii?Q?753fZol9pYuJvI3+6Q+DTWuP1l8CbkPrW+NQHh0FOMd8WiaOxUYSE5UlP7G1?= =?us-ascii?Q?I8oqNgy6ep19p6d/ySwbQwNV2Ha+N/PM31tLUiuJMkGp0BAVX/9v0ZimI2ZL?= =?us-ascii?Q?RUWP4fIaHt1oSzqNQNT/slNVjFZAcTVkVpDEAydSjXEa7oIl/aSWqfWUzxPP?= =?us-ascii?Q?gLvfFtRdr0uDJyLrvU0iNEf8p3QkjpNZ20jqhfGD7iOQoHbAti87DvGN2VtJ?= =?us-ascii?Q?wJres6zLq3jCOC8u1wCU5ZEX74aE+mdvvjUGjBFETb8e3Pzo6JF0xaI5Oj/R?= =?us-ascii?Q?X6FuLZsWrBdPJx4Ft0R6+dVsVatqovGaZJOUHXGndVtbfgVmgoisx0cicrfZ?= =?us-ascii?Q?ZD9+YJswunoXHdlU32RZ5Re0GsEqYLeu0/pV6rPcDpUnFgamF9QTwqcrG/dj?= =?us-ascii?Q?osacmQYNBBIsnZgaEe96DSQgU/NFwfXUlmX8oKOxf+ND1fmV81v4tm5V8NRq?= =?us-ascii?Q?P5J7zoO56+aXfPAvqOONnuiIGPHM2TK23XGz5leDVB6Ituz0vc9EgyDUdv33?= =?us-ascii?Q?ORV2E4ijClBoSx+pV664hWO0kOoDIuKkdrGBFXfuWNnc2XAiu/qPHSIiMa1b?= =?us-ascii?Q?NjgWc1jAL3YdgbxWavomIkMGKbm0bdaPIwsPxItInpa2geuEUe1REwe9LLfA?= =?us-ascii?Q?VBoWUqQjKf68DIIjzkspuKi5zG2dQIrL6ji5nFTa9PqlUXpA+8qPdnQeooDZ?= =?us-ascii?Q?wppQeCDrai13qjE/QEc5K2m7QYcKZiQHgX4cwvE/ab8vHxGpq+eAU1VnrnkU?= =?us-ascii?Q?4MHGJZFSeLgKNz46AzJEyoNPzt7Wj8fAmuPTd5o5t/clgeJ9fLJCm8x/Ms4G?= =?us-ascii?Q?Z0TlzULuCeej2Lq4AunNrdHgqayokFuL5tyXfTQ+yQRAcpTGIZt6ZQZllWyH?= =?us-ascii?Q?f1nOH/wCNdlfooVBU6XuAxnNCsLnBpmLKfA561f2iAvnoICFb5auSO5xjfsy?= =?us-ascii?Q?eI4CHKXzXjKTxZcp5LZYPusUZeqVlGn+F4yR08cH0Z4R4FFbZGfEhNSPm8Fs?= =?us-ascii?Q?Q5s/2GJ9hvOvJSloze83ROIf69W9/LVsaMWobt3R0oNpAxGtsDzdKf1GW5ha?= =?us-ascii?Q?7qqw3LogwI5jhITS1xZv3stwIjQeWjS1AoaLSllcdmui/qBcsh6ML3yXM/yR?= =?us-ascii?Q?1qA3wxriZPElZJVgYUtDIY2nK6FR10gIUKhi94cMywDgsYmhJwK3QsNn43XG?= =?us-ascii?Q?JwxBUZU93UqAP5ys9O2ZGVL+zm37WNcFk2Buud44Z6/fs3CH1UpVHLv3ZYjC?= =?us-ascii?Q?ugkXwR/XeJx0ULMw0ZVyEOE6EDkIOgyj9D6D5Bcos1c21q3z2acqmEv/N278?= =?us-ascii?Q?gWxSNWA/vQMghD/fUInIDU2yjwyXrd1rt9OC?= X-Forefront-Antispam-Report: CIP:165.204.84.17;CTRY:US;LANG:en;SCL:1;SRV:;IPV:CAL;SFV:NSPM;H:SATLEXMB04.amd.com;PTR:InfoDomainNonexistent;CAT:NONE;SFS:(13230040)(376014)(82310400026)(36860700013)(1800799024);DIR:OUT;SFP:1101; X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 08 Jul 2025 00:07:31.9609 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: 587f837e-7313-475c-5a4d-08ddbdb36f44 X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=3dd8961f-e488-4e60-8e11-a82d994e183d;Ip=[165.204.84.17];Helo=[SATLEXMB04.amd.com] X-MS-Exchange-CrossTenant-AuthSource: BN3PEPF0000B374.namprd21.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: LV3PR12MB9265 X-ZohoMail-DKIM: pass (identity @amd.com) X-ZM-MESSAGEID: 1751933268983116600 Content-Type: text/plain; charset="utf-8" On real time configuration with the null scheduler, we shouldn't interrupt the guest execution unless strictly necessary: the guest could be a real time guest (e.g. FreeRTOS) and interrupting its execution could lead to a missed deadline. The principal source of interruptions is IPIs. Remove the unnecessary IPI on all physical CPUs to sync the TSC when the TSC is known to be reliable. Signed-off-by: Stefano Stabellini --- xen/arch/x86/time.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/xen/arch/x86/time.c b/xen/arch/x86/time.c index 59129f419d..bfd022174a 100644 --- a/xen/arch/x86/time.c +++ b/xen/arch/x86/time.c @@ -2303,6 +2303,10 @@ static void cf_check time_calibration(void *unused) local_irq_enable(); } =20 + if ( boot_cpu_has(X86_FEATURE_CONSTANT_TSC) && + boot_cpu_has(X86_FEATURE_TSC_RELIABLE) ) + return; + cpumask_copy(&r.cpu_calibration_map, &cpu_online_map); =20 /* @wait=3D1 because we must wait for all cpus before freeing @r. */ --=20 2.25.1