From nobody Fri Oct 3 20:24:56 2025 Received: from NAM12-MW2-obe.outbound.protection.outlook.com (mail-mw2nam12on2065.outbound.protection.outlook.com [40.107.244.65]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 79131266F00 for ; Mon, 7 Jul 2025 18:33:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=40.107.244.65 ARC-Seal: i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751913224; cv=fail; b=lv4ns2GgOORzYHDan0fceJas1YT0zdVGsniAzlbIWxSBwhkUeHttqTKI+MKQIPHCkVoCHq4Um1h1ddJBbFJNFj7ZWbClFFU90ca8Zzz11YywYoEIEJb9eyALoq7e0GlqQpXipj0JvnLLMlQwWovNlEELRKyDXyBwyf7fYzgcw14= ARC-Message-Signature: i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751913224; c=relaxed/simple; bh=1qRTFegq6jbR35j+HO3dWt9MTr5BPSw61QhchgDSB5s=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=oGWhA3F+3JFpBf/ylk8PhKusE2fbg7UB2LQ/iQtKVn5/SWyTkeIeE2VQLiBbvuEGn9D1WN7/ria2+Tvh3v5lSl2GWnPump5NW0TSU3gsU4jZ+OjAl9uHNa5KEMsMvIguck+RU2MAXqmJpj0dFaJMBpIOxsbEVOIVPrx+ykHbXyA= ARC-Authentication-Results: i=2; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amd.com; spf=fail smtp.mailfrom=amd.com; dkim=pass (1024-bit key) header.d=amd.com header.i=@amd.com header.b=BJqbPDaP; arc=fail smtp.client-ip=40.107.244.65 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amd.com Authentication-Results: smtp.subspace.kernel.org; spf=fail smtp.mailfrom=amd.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=amd.com header.i=@amd.com header.b="BJqbPDaP" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=Jq+gyc0UUlDv71PnT+0e42k0CKsFi7N6GhjfPINuP9bxacXSk1BtxNE94WlzBuFTphh73g2/d+5iQ73Xmu+40Ms2LSEY+GtupXjCWh+MUqJvzJoOWhDrUJdOVXbrh3zCtEWyCyF/NC+cOro/UjdDzAUuG6MSYVc/xaMJ+gV4hbatU/QR8vm5DO/2GEUFK2GBit017dgkYRfkon1b8b9Ag/mylPsUd44EHTM64/f2jPvTn76FCLT80V+y1VMHIBsbcFG3EjqILVxK0Fav/4mlZcmGLWQnqV1n1NlmzZMijZWh9wQlT7A8U+DGhHQDI3zsChfsT0+b1lpnjeEIF+mFbg== 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=BNu0CsLHTiWN3YqjotAZi5qpWZvCZqbxwKeCGzQ2bRE=; b=OnPgR7H4F63nXaqrBA1LafJh9tf90LIQzPK89MycjWoD7/v8aYJgAqrbL53OWDMQws4s319gi5mhlE5OJpTRtp3tjRvzu9PQWyNYDLy+xQTy7zFdbwaihKo/YTo+K49ZyRRBgGpMyCQp2Hw5zFfYOXdST5xXgUAwCOUu2/3KdBSpNebhSCSSDIsVfmGPxQhgOplFK7Qx/ezasXKeCtYT8umFLXTsq4kLuSm/oXibTTcs3LlOtsNjjZswxByd2MM6xzaKgstN0XIJfY6O8s8NFjpVOyMUboY4X4KE1mxzHAilmn6hRxSZHAJJKJ+dzq6/GoplBTNhl3RV8S1kCnfBuw== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass (sender ip is 165.204.84.17) smtp.rcpttodomain=linutronix.de 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=BNu0CsLHTiWN3YqjotAZi5qpWZvCZqbxwKeCGzQ2bRE=; b=BJqbPDaPEoJ/u2IrYu5qO4acf08yA/JuoL++AKGkr3IWUWInh+DbVjTKni76eZ7mEduxvDHai0Poi03oHyriQ7G3cNwwVQhcAvNSmVrE+Yt6C47qFUCtVbBL0OGmGjoC7/dPtd++MoVqSITURsC3+zUEamfMPuntxS/88i7h/aw= Received: from MW4PR04CA0263.namprd04.prod.outlook.com (2603:10b6:303:88::28) by DS0PR12MB9398.namprd12.prod.outlook.com (2603:10b6:8:1b3::19) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.8901.24; Mon, 7 Jul 2025 18:33:40 +0000 Received: from MWH0EPF000989E9.namprd02.prod.outlook.com (2603:10b6:303:88:cafe::d1) by MW4PR04CA0263.outlook.office365.com (2603:10b6:303:88::28) with Microsoft SMTP Server (version=TLS1_3, cipher=TLS_AES_256_GCM_SHA384) id 15.20.8901.26 via Frontend Transport; Mon, 7 Jul 2025 18:33:39 +0000 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 (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 Received: from SATLEXMB04.amd.com (165.204.84.17) by MWH0EPF000989E9.mail.protection.outlook.com (10.167.241.136) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.20.8901.15 via Frontend Transport; Mon, 7 Jul 2025 18:33:39 +0000 Received: from tiny.amd.com (10.180.168.240) 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 13:33:34 -0500 From: David Kaplan To: Thomas Gleixner , Borislav Petkov , Peter Zijlstra , Josh Poimboeuf , Pawan Gupta , Ingo Molnar , Dave Hansen , , "H . Peter Anvin" CC: Subject: [PATCH v6 10/21] x86/bugs: Add attack vector controls for GDS Date: Mon, 7 Jul 2025 13:33:05 -0500 Message-ID: <20250707183316.1349127-11-david.kaplan@amd.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20250707183316.1349127-1-david.kaplan@amd.com> References: <20250707183316.1349127-1-david.kaplan@amd.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-ClientProxiedBy: SATLEXMB04.amd.com (10.181.40.145) To SATLEXMB04.amd.com (10.181.40.145) X-EOPAttributedMessage: 0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: MWH0EPF000989E9:EE_|DS0PR12MB9398:EE_ X-MS-Office365-Filtering-Correlation-Id: e486af17-ba94-4d29-62a2-08ddbd84cb00 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|376014|7416014|82310400026|36860700013|1800799024; X-Microsoft-Antispam-Message-Info: =?us-ascii?Q?orSrSoNxBA+E+hkgCrOT5gWhBzV1j88HFPA3t8Ag5K3r35Hnlvin7l7hgMJ1?= =?us-ascii?Q?7ITXYUsphVfuNPKOrLYPgzMer2QhTA6eQ6cP9wUkK3a8ZB2cN7fnn7H8di+f?= =?us-ascii?Q?5porpD4amCd2P7qbOG70H5qYXsUkEiOA3izIkvxJ330p92lrCOYuZq5AjASs?= =?us-ascii?Q?0p1+fGHWLvmICUCK1igFh3h9Yk0i+er38hAjQPaOgxicmqZdFosEcGWuVrNN?= =?us-ascii?Q?vszjyZ8BO/NGBZRFwblFyIK6zLMUTRFmEPMmCJfRr8l7+4zNi194iIXrUCzP?= =?us-ascii?Q?cjxerp46ZRKRdPv2mqxKe0bTW2frDXiZteVtCwc2gg1gCCVnj73gK0BeMzom?= =?us-ascii?Q?SfaQaldaiS2Vi04SLYE4vxjYhG38ieXbptiVPelQ1HFISyc6Ru43AskK8D6G?= =?us-ascii?Q?or4xMarwQhT26CsN4sARQewdwafS3zOMyD4VyPWajWHDmh/oqBgpk2uhcEhv?= =?us-ascii?Q?6ON7mgm+l0BtxkqacQ4j1uzZ/bdd8q15fy5+tTXLZucbUr5OjbV9Q/JkqZhZ?= =?us-ascii?Q?hWUxPBbXJyjRUoFfg8QJawyxngZ0mkzKsio+UkZHzAqehw8Zhh+aRUCpQzJd?= =?us-ascii?Q?b4Vd7Q6zJ65Eb2T2zyXPHLnKc4vab4QyhvTaGuvX7ckPCPzgMBFiraDE8SBb?= =?us-ascii?Q?E/zcNaMX0k28K4UUprOq8vX8uVuqTKWSQcDd1anAOHfBlcwpxiT1Dx5qu4x1?= =?us-ascii?Q?qpU59BcFx9BAvITTqdsdm1mH/+SFlAzENU8IWwMSZtdl05f1F4Hpbth+ySzY?= =?us-ascii?Q?7A/7O1u0wfJZX0MtA9r+s2YXtraSKcKzgHkwJjyXoEbgCPgVGec3MwLV/ijO?= =?us-ascii?Q?FhkCR8PLUlg/4a1rLLEXnwpuqiP1sJOkyujxGiDxlwxEfH8++kTkt9axvyLS?= =?us-ascii?Q?CnBJdoJ3EDh+Ess77HEcOVNi2YEWJ3O2NY+AyrKhn36ppb7ZEwhzRbZBunhB?= =?us-ascii?Q?PoZetYLk0W99ubvgS7iaEPT0PMDiwzzVgamzde6noRG58JCsXPKMeA5yC1kG?= =?us-ascii?Q?GNmjuHHMqJu9orlRPS0RQB0DAwZUf1lw+cFKztdI54uxQpFQwdpC4UjUK0/t?= =?us-ascii?Q?CpmeZccve4QnFTtteR6VYnNXVweB4WpkCG76IKhzv71LifXU4aBhSEbkRu7z?= =?us-ascii?Q?qAFlkVI4XaBJ1CBDYMkR6g7LRYIxKNsYUr31KvTqOeL7TyZQa2gKp5YJjRG+?= =?us-ascii?Q?G0EcYsIRV7zyGDi+LCJ4SJRa3hNDgGP0Dfg6sUVC78ugLBDGAWqdaexUP3IE?= =?us-ascii?Q?vsLq+bLYdq0AI8kZaND0J9itRLs3FTQZCPNJHIhpAeUsY6swOzLDYjX0T/7p?= =?us-ascii?Q?JWsoHwBfuSBBepq/5twhBeAvFH4Sy7nuAjBTrxgUBt2UETuaAxsBJY0yxjyi?= =?us-ascii?Q?wyatVMdergwyhP5rW8uo1NxhTu/SlDCyrBHk4UJ945h3KMlNflZPviw282B0?= =?us-ascii?Q?+wsf8ZivTjxrqunC71XQtsTyLt/tv3YXdsecwnSKvJX21rr48ypeNmInJYbB?= =?us-ascii?Q?zsZqayvCGqsW0tYeb5xUaJJgWoUQIruh/g2I?= 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)(7416014)(82310400026)(36860700013)(1800799024);DIR:OUT;SFP:1101; X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 07 Jul 2025 18:33:39.4272 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: e486af17-ba94-4d29-62a2-08ddbd84cb00 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: MWH0EPF000989E9.namprd02.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: DS0PR12MB9398 Content-Type: text/plain; charset="utf-8" Use attack vector controls to determine if GDS mitigation is required. Signed-off-by: David Kaplan --- arch/x86/kernel/cpu/bugs.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c index e01fb83daa07..dc3f9a2e6984 100644 --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -1026,12 +1026,15 @@ static void __init gds_select_mitigation(void) return; } =20 - if (cpu_mitigations_off()) - gds_mitigation =3D GDS_MITIGATION_OFF; /* Will verify below that mitigation _can_ be disabled */ - - if (gds_mitigation =3D=3D GDS_MITIGATION_AUTO) - gds_mitigation =3D GDS_MITIGATION_FULL; + if (gds_mitigation =3D=3D GDS_MITIGATION_AUTO) { + if (should_mitigate_vuln(X86_BUG_GDS)) + gds_mitigation =3D GDS_MITIGATION_FULL; + else { + gds_mitigation =3D GDS_MITIGATION_OFF; + return; + } + } =20 /* No microcode */ if (!(x86_arch_cap_msr & ARCH_CAP_GDS_CTRL)) { --=20 2.34.1