From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from MW6PR02CU001.outbound.protection.outlook.com (mail-westus2azon11012015.outbound.protection.outlook.com [52.101.48.15]) (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 550E3284672 for ; Tue, 24 Feb 2026 18:02:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=52.101.48.15 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771956164; cv=fail; b=BeXY3b7oTjYz+e1oIbXMeZWmunnbP7e+BVigUDLjtxuZnD2CybYzTw7Fu30hzf6OWXrTO7TzCXtRD0uJ4YRxP9IYfuGBpG+BYCNJsqntZpqkgxRcj9ESNTrYNrHWn5wBqvvyBr/Of4XwfZL+zbX23r+3ZYzO0ZEdB6V7AZH1GfY= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771956164; c=relaxed/simple; bh=CUZ0Yp8Ctj5iGXDOBzggNJqtDrYM6UhDGLbGltHeLtM=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=jyPYc/NfKrtS0nfBBdhvqYGdqkelaaO5T476mlJZa35vaq1hXhnQpHqUlg820BQLh9RsTRluQlpAHstRmfUnDuEvMeCxaBLEhTwr3l5xm75vLdFx6Xu8uuB3HuX26RfR+yIWRavMV4E9lcdSMm6iWCXD97igS4kmwMU4ALoHkU4= 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=3SGUz/vS; arc=fail smtp.client-ip=52.101.48.15 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="3SGUz/vS" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=HnRshgX2BGDippYtUHJaTgYqODBYcYb2++hLXn7uZTBzP6bzG2SCFrbptKQ7dl3iE9DO4dbuxP2xoGDzeK6qfSH/srpatpMOMfXWJS61i92GNR4yEQMQasv3t5Hsyi0sUNzb5EIn00+n0wIswuIjpDOKfc+62KDdRO9PTuz90kaFNCbIcc4m+nh1am8coUfkhQK8UjBv4jMHtygMwIsBzab6yDwmnLqNg4R9Fw9mpOUgE7RMsYmuyKrwrIhqwtuyDodPVzAZI8g5WgR1uhSczCItzBNYPytIbq5toQb0bjD3MrBr5a7SmRdMDsQybOJVQGn6rysH9t4nZJPq+OOD/g== 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=Cpez5mwt4d/Bf2YizbgXqk90L42ZNm+bNgHBZd7xUck=; b=UqLwpa5zqAaH8DpTe+ay7SI3dvWq+mUICTm7UWsfpPOthnbQW+3/Q9KLVMJukO5R1xIXMBuCWb0mxfvgvY314OA+KHCXB/pW1ZMCkncZ68YEPbCHEhnwN1PepWLSpfbIkEPMyLum8GmnlPHUEzmi+M96i0gGU9TNvhe2uuIq6oE84y/qQgrYmX+5AX69LDCYDYsK0yrkhLKDdIxkM4FpVwaRSTta6QHLdpNj+C7WUGt8Tv0TzTY2WMxb9k1oGuJsc2q+LiTK7Ke5OXjQIEJoMn5G0X9vLaTAiEFTu/cZ5UV1uUBpAViJXtCl0TU5fzwXaKcZqOvL3i0s5fKIv7ZAmw== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass (sender ip is 165.204.84.17) smtp.rcpttodomain=vger.kernel.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=Cpez5mwt4d/Bf2YizbgXqk90L42ZNm+bNgHBZd7xUck=; b=3SGUz/vSGLBz3HQXgRjyjzRYHXftD3TfgGYmclQjurGdS3yHLBaw7yEAOuTGt3zZCIiT8EbnEimiQF8K3CUcVUI4wSRvaWw6aBhd4lfFo4rk24s40yFwlf4H6ZoVEUpea53XAOjs7tFCci5/GErkIH8TEeFoeu6mJICd06RSK94= Received: from BN0PR04CA0090.namprd04.prod.outlook.com (2603:10b6:408:ea::35) by DM4PR12MB5961.namprd12.prod.outlook.com (2603:10b6:8:68::21) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9632.22; Tue, 24 Feb 2026 18:02:39 +0000 Received: from BL02EPF0002992E.namprd02.prod.outlook.com (2603:10b6:408:ea:cafe::91) by BN0PR04CA0090.outlook.office365.com (2603:10b6:408:ea::35) with Microsoft SMTP Server (version=TLS1_3, cipher=TLS_AES_256_GCM_SHA384) id 15.20.9632.22 via Frontend Transport; Tue, 24 Feb 2026 18:02:27 +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=satlexmb07.amd.com; pr=C Received: from satlexmb07.amd.com (165.204.84.17) by BL02EPF0002992E.mail.protection.outlook.com (10.167.249.59) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9632.12 via Frontend Transport; Tue, 24 Feb 2026 18:02:39 +0000 Received: from dryer.amd.com (10.180.168.240) by satlexmb07.amd.com (10.181.42.216) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.2562.17; Tue, 24 Feb 2026 12:02:37 -0600 From: Kim Phillips To: , , , CC: Sean Christopherson , Paolo Bonzini , K Prateek Nayak , "Nikunj A Dadhania" , Tom Lendacky , "Michael Roth" , Borislav Petkov , Borislav Petkov , Naveen Rao , David Kaplan , Pawan Gupta , "Kim Phillips" , Subject: [PATCH 2/3] cpu/bugs: Allow spectre_v2=ibrs on x86 vendors other than Intel Date: Tue, 24 Feb 2026 12:01:56 -0600 Message-ID: <20260224180157.725159-3-kim.phillips@amd.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260224180157.725159-1-kim.phillips@amd.com> References: <20260224180157.725159-1-kim.phillips@amd.com> Precedence: bulk X-Mailing-List: linux-coco@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain X-ClientProxiedBy: satlexmb08.amd.com (10.181.42.217) To satlexmb07.amd.com (10.181.42.216) X-EOPAttributedMessage: 0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: BL02EPF0002992E:EE_|DM4PR12MB5961:EE_ X-MS-Office365-Filtering-Correlation-Id: 5bde4f99-bc26-45e0-b7c3-08de73cee5ec X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|36860700013|82310400026|376014|1800799024; X-Microsoft-Antispam-Message-Info: =?us-ascii?Q?gykOjVudNgotv66cQhr0q4Htuq73rRXgsbtWShhxewochyvWouTp0hLTGodM?= =?us-ascii?Q?M6gqg91WZaq/FqfwADclETP6G5Z1UmTtKwUUSXtAQHTfZkFz0qXr2uJoQbm6?= =?us-ascii?Q?oqLEyHXgJh3sGEc7eiKUfYjT5rzHjXZ4pH4GHk7oyRtf4hqv/wVvZLj7YBlS?= =?us-ascii?Q?o0ApYwWd8cANKKB0CHbXxKO58ctQEjgI41llb0LGM2V4o8P5lgjTrjOxXVXg?= =?us-ascii?Q?y6BtGL68iowK9khlyP1ugDyxoukcyawXZDiWRQM8KgOv+01L+/jfcHU6auh9?= =?us-ascii?Q?8p9jI2vBjQ27mT6tF2JgUEOK3IvzMVMx63a80KIiCLDGmmkjQRzhZGkcXPAj?= =?us-ascii?Q?TlCrwqTyPmmpifx/ZvbDXAVsZWWOnbG8tP4+/dywx6RhAuz8pwXuUQS9uHCs?= =?us-ascii?Q?wMzDVPsAoWXB9ZYdfFq7zlm9Xog9aQHO28VIWAtVDpvn0JXAaLHu6M0YM3ej?= =?us-ascii?Q?l9MtOZKFk/AotZzuwvkhkRL5sKlA5Lcv2WF8ebii0IUw2UXxNClt4e18OLKl?= =?us-ascii?Q?YaRIOu5V1tFipMZfljG8B2ROkoBEtDCSpigcfvITYoRhFcItGqx9F3+k/0qu?= =?us-ascii?Q?tIPv27MIrKmyorwjYZAuRUbOfner2gB/8YQlnTqiUmap2qRVNRS/SJrAZOv6?= =?us-ascii?Q?YU8FifXX8GRHpz/XNjScxR6HPCIYe5j6+qLdCboVPTBHEUqZGbUYW2ceiyn3?= =?us-ascii?Q?cdfwYaq/gyhlhseaHQp1PDCpqn16mwaDT8WcsYT0wg1eE+s9+M63fu3XtQDt?= =?us-ascii?Q?W/F54uOW9bPuUnKFNQ6rRByh8+3GFSQXHtrWyMYidyepbfRtaFRFY93xfUaU?= =?us-ascii?Q?jR7cHCKrBIx2jdVxQVAr7QvafLDYzaWMCC3ojP4rf6P67aMFon+BDi2cEg1T?= =?us-ascii?Q?I1EA1B4S174toakH2zosovS4l9qVIr84K8utBVUb73t51rKaoVz8S0sy+Fh4?= =?us-ascii?Q?5+pFGcFwYJ58QYQiJ/6GeX1nsgpHoSheW6tFVr9cr51Bnn/dosD5ZeIDJAc3?= =?us-ascii?Q?hrRaIuwZEGNwyX7pvhfZg0jx1paWk/rnUT7QSgI0MQZa7fuuvoG2pjtWXSi5?= =?us-ascii?Q?NNLEUgPPi6kEf9n2k30/9bI4As9nTM0a0ppE7oP8yeTIaUSEUpmqPgi2fU2S?= =?us-ascii?Q?1r80Q1jDZDGT0WiF5hksqkbzQVcXRBx+Y9vgHv/TdJtCrO1IyhhvMuowNTI2?= =?us-ascii?Q?8tl7jKhVGR2kHBGbxkWnCGpmc6/IUecCApjI3WcNH845kpOtOK7ht7BZwwCr?= =?us-ascii?Q?tiT7XFKnE/KPrZWVL0IP+foLuOzmSvxWimHI9f4HB/sBBW0c/qS0SzQkw4nC?= =?us-ascii?Q?ksdsJMinjSbSMc/lknOUXnRGlHM1NO0V+ljaakvOA/lfEf0ZVwrwNd3gCjpB?= =?us-ascii?Q?cG42vKiuZBP3TrGxiRgBMLpZ7QszegsAFSdFUPB5v3Ko4UgIKqA6GqlWRgqd?= =?us-ascii?Q?ATPktBvRIjiVifkEZrkLQzHgwysCzqd/u92v1BAQ3NKm8vVu66OrjWAb/Ha7?= =?us-ascii?Q?USD0OuUld2Czxpjzj/4Mv9evaktnHiR5UM22pHX+k01Hlg7QJWR8nuOjA14o?= =?us-ascii?Q?02gg9YLkDCjwJjt85UzOG4OozFUisnOg2RHScADhCXQVNPetzajJEMfjPION?= =?us-ascii?Q?OMWP1aAjHNb//FWR/7v4lRZCd8isPrSpzjqYpeOyfyPLjdsGuJCK0IpoUTDQ?= =?us-ascii?Q?Q44Ztw=3D=3D?= X-Forefront-Antispam-Report: CIP:165.204.84.17;CTRY:US;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:satlexmb07.amd.com;PTR:InfoDomainNonexistent;CAT:NONE;SFS:(13230040)(36860700013)(82310400026)(376014)(1800799024);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: cnH2Vlt+RsXF8e6MrOGZ0kxqgImBI+nf4E57GJeu8ra1mlOSdJw/UEY/TmsD0H2E6vceHjGmRI7R0wzn8k45GjEL5wnv0IGm1jBGaNylI+kwkb6KBuSlFHgdN07vhnYtMKNWx8U+8z8isKFhhY5mqlL0xhhtvyg9D/vKZzIwBbCSgphtTRVN98+wLT2wFpmiamIXzLJSDQl28Ent6Ht4Y1SmW/gdZP/yUNXZMSpdN23yfb3T2RRJ4IBa6ercL859hamsx3dgSJ7dfD7hbjrYB16cyDrhTBUfY8FR6Do6iKbWOQSkKFcKQ+fbGpQVCGmLp2i7G1T+k3BTwVwwPGQegAvsgUr2AXVM9IjCmoFeNs4ap51+p5wZAAPLk0oSjEs2uH5vMQf97bRjj76Hnj62ntMEZulhs1leC0WAVWWpxC2v+U1iArniXH3433PxMXOS X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 24 Feb 2026 18:02:39.0712 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: 5bde4f99-bc26-45e0-b7c3-08de73cee5ec 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=[satlexmb07.amd.com] X-MS-Exchange-CrossTenant-AuthSource: BL02EPF0002992E.namprd02.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: DM4PR12MB5961 This is to prepare to allow legacy IBRS toggling on AMD systems, where the BTB Isolation SEV-SNP feature can use it to optimize the quick VM exit to re-entry path. There is no reason this wasn't allowed in the first place, therefore adding the cc: stable and Fixes: tags. Fixes: 7c693f54c873 ("x86/speculation: Add spectre_v2=ibrs option to support Kernel IBRS") Reported-by: Tom Lendacky Cc: Pawan Gupta Cc: Borislav Petkov (AMD) Cc: stable@kernel.org Signed-off-by: Kim Phillips --- arch/x86/kernel/cpu/bugs.c | 7 +------ 1 file changed, 1 insertion(+), 6 deletions(-) diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c index 4eefbff4b19a..67eff5fba629 100644 --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -2154,11 +2154,6 @@ static void __init spectre_v2_select_mitigation(void) spectre_v2_cmd = SPECTRE_V2_CMD_AUTO; } - if (spectre_v2_cmd == SPECTRE_V2_CMD_IBRS && boot_cpu_data.x86_vendor != X86_VENDOR_INTEL) { - pr_err("IBRS selected but not Intel CPU. Switching to AUTO select\n"); - spectre_v2_cmd = SPECTRE_V2_CMD_AUTO; - } - if (spectre_v2_cmd == SPECTRE_V2_CMD_IBRS && !boot_cpu_has(X86_FEATURE_IBRS)) { pr_err("IBRS selected but CPU doesn't have IBRS. Switching to AUTO select\n"); spectre_v2_cmd = SPECTRE_V2_CMD_AUTO; @@ -2247,7 +2242,7 @@ static void __init spectre_v2_apply_mitigation(void) pr_err(SPECTRE_V2_EIBRS_EBPF_MSG); if (spectre_v2_in_ibrs_mode(spectre_v2_enabled)) { - if (boot_cpu_has(X86_FEATURE_AUTOIBRS)) { + if (boot_cpu_has(X86_FEATURE_AUTOIBRS) && spectre_v2_enabled != SPECTRE_V2_IBRS) { msr_set_bit(MSR_EFER, _EFER_AUTOIBRS); } else { x86_spec_ctrl_base |= SPEC_CTRL_IBRS; -- 2.43.0