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client-ip=165.204.84.17; helo=SATLEXMB04.amd.com; pr=C Received: from SATLEXMB04.amd.com (165.204.84.17) by BL6PEPF00022573.mail.protection.outlook.com (10.167.249.41) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.20.8534.20 via Frontend Transport; Mon, 10 Mar 2025 16:40:50 +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, 10 Mar 2025 11:40:48 -0500 From: David Kaplan To: Thomas Gleixner , Borislav Petkov , Peter Zijlstra , Josh Poimboeuf , Pawan Gupta , Ingo Molnar , Dave Hansen , , "H . Peter Anvin" CC: , Brendan Jackman , Derek Manwaring Subject: [PATCH v4 15/36] x86/bugs: Restructure l1tf mitigation Date: Mon, 10 Mar 2025 11:40:02 -0500 Message-ID: <20250310164023.779191-16-david.kaplan@amd.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20250310164023.779191-1-david.kaplan@amd.com> References: <20250310164023.779191-1-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: BL6PEPF00022573:EE_|IA0PPF12042BF6F:EE_ X-MS-Office365-Filtering-Correlation-Id: 4dc71f47-69e0-476a-96fa-08dd5ff25114 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|82310400026|7416014|376014|1800799024|36860700013; X-Microsoft-Antispam-Message-Info: =?us-ascii?Q?wiCuAkqGFLM/1YvE3b846VnbcXRyGQ2i+f9XdoOE0JE/fiJuIKhJfzMYHDDi?= =?us-ascii?Q?7WSeV1GENZEUvE9KO4hIvKLnwKYwILAfHBeFUSHr482eNBSirndvNRCHoy9U?= =?us-ascii?Q?syc9lCcBwHMyN3DoXQ3H9wC9YZPVAZeukqc14igyx1kOF2y8xFPyJcRp2azG?= =?us-ascii?Q?p7k9Y5RsAg5xfSDufA/cXf5oW0CE451sS5dQz/cn7DZ1+rvojpsdnvBEPHBi?= =?us-ascii?Q?2ZgFKPE0VdqvN2jT8I9cdP+dx0H8QSEg8CICN0ehReN0DH19g31tsrkpaWhC?= =?us-ascii?Q?UE1sO4AHsl/vZhijBkWis3HbSmsjVVD+7LaQv4LyTUCWuWjuxdAMrl32h3DX?= =?us-ascii?Q?OSG2eotJ3vzR1z8mBqtW6oSwkSGGSRueueIY076agFkkvfaMGwq3gxarLt0b?= =?us-ascii?Q?MPfYl7XGZoWwBus5khvFtjB2KREFIXyyEeSozdB/b6y+Xwp+yW6p3pAzifOM?= =?us-ascii?Q?45PywVs3um+35J0vxY84CM9z7A50YIP9hqTdZW/6TkSHDvmzdl7oS3/E6wKe?= =?us-ascii?Q?J5Z8ffz9C8fDK1Bo9/MfzCySfNrkWDyb240e3GAcCGrI57jCFxLECucoXc3K?= =?us-ascii?Q?2T7ns3XgVGXWB6Y17UpoTWlMy8TFFJPJxD7IaCbFl2J194c/sYniKNncU4rj?= =?us-ascii?Q?LCe72wuW5ezeHqcYwO7AXpEJshngcfU0nvzh+IotXvlaEQ/WmBSYmV90feyD?= =?us-ascii?Q?jVG3KDaEYA4XOU60rg/d2rjvU4m3E3+MocENMQ36O4oQ4o/nY2Nd7C9KUKfp?= =?us-ascii?Q?9VOgGB1ZiMwsc9qoWrgFXNpi4T0Ij71njehnhF2zo4XeBXSJOj7RwEksn7GZ?= =?us-ascii?Q?HnjkPIdH5moGzay4U9T0IsiM8Fx9d/yHSaiqB77y89UntxYx++6b8pOyrbhc?= =?us-ascii?Q?iRKwxHlpV2bCGb5zQXd6fYb/6ILk1c2g4Uf4rQ5LNWjhHQtUV1150RRq6cKd?= =?us-ascii?Q?dhjXRSKYtdkos6AdsxHGoYb0vgUQ9ixW1iP20gI2ePsyT3i9Nx+oq6koT/KD?= =?us-ascii?Q?r9aOrJJ+h1dKXRV99saUpfQaX0/tdBum4ZSQG59OHhU2aXKmsPiUb1+k8cTi?= =?us-ascii?Q?x13PP8VX1qRMmU4y6hKwaskiZijGrDwbhN3Fe3l5O1+oRjD8ZMbNPfLyGQQ6?= =?us-ascii?Q?Nd6MYVd1Sj3MAGU/MeCf97IrUiA7pkHsABzymVyM767jrxQN8auePdFin4jk?= =?us-ascii?Q?N2uyXx8xCn2tZBv3swxebRnaLjVu2036HVTGCD9sVnzNXhwz38gddPQVlKeT?= =?us-ascii?Q?RVxSRK7Q8rk+UngMwe6pLnat9jGV+z9OmiwfkQFX8vyxmA7yPeyxbuwBocqP?= =?us-ascii?Q?L3TAt7ZHaDELY+/Uc34DCgEi3P7kk1rFhjM881zdi6SLizNKNCwTju9JHgxk?= =?us-ascii?Q?zMZg/WCq22D7bafyMFZK7mjzfMnJoSoMsCLVw6CRk5iHJYRZdvZb4c+WnmLQ?= =?us-ascii?Q?+CidMFQqZ8vzjRu5MHH4PMF7Ans3cJNaACVlyRnSq4bbr+x546vgHLkS3HdU?= =?us-ascii?Q?7TynGgpRQIRyxos=3D?= 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)(82310400026)(7416014)(376014)(1800799024)(36860700013);DIR:OUT;SFP:1101; X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 10 Mar 2025 16:40:50.3037 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: 4dc71f47-69e0-476a-96fa-08dd5ff25114 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: BL6PEPF00022573.namprd02.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: IA0PPF12042BF6F Content-Type: text/plain; charset="utf-8" Restructure l1tf to use select/apply functions to create consistent vulnerability handling. Define new AUTO mitigation for l1tf. Signed-off-by: David Kaplan --- arch/x86/include/asm/processor.h | 1 + arch/x86/kernel/cpu/bugs.c | 25 +++++++++++++++++++------ arch/x86/kvm/vmx/vmx.c | 2 ++ 3 files changed, 22 insertions(+), 6 deletions(-) diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/proces= sor.h index 5d2f7e5aff26..0973bed22172 100644 --- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -734,6 +734,7 @@ void store_cpu_caps(struct cpuinfo_x86 *info); =20 enum l1tf_mitigations { L1TF_MITIGATION_OFF, + L1TF_MITIGATION_AUTO, L1TF_MITIGATION_FLUSH_NOWARN, L1TF_MITIGATION_FLUSH, L1TF_MITIGATION_FLUSH_NOSMT, diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c index 1d77747e0f74..b9b7f5967f1e 100644 --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -67,6 +67,7 @@ static void __init spectre_v2_user_apply_mitigation(void); static void __init ssb_select_mitigation(void); static void __init ssb_apply_mitigation(void); static void __init l1tf_select_mitigation(void); +static void __init l1tf_apply_mitigation(void); static void __init mds_select_mitigation(void); static void __init mds_update_mitigation(void); static void __init mds_apply_mitigation(void); @@ -234,6 +235,7 @@ void __init cpu_select_mitigations(void) retbleed_apply_mitigation(); spectre_v2_user_apply_mitigation(); ssb_apply_mitigation(); + l1tf_apply_mitigation(); mds_apply_mitigation(); taa_apply_mitigation(); mmio_apply_mitigation(); @@ -2554,7 +2556,7 @@ EXPORT_SYMBOL_GPL(itlb_multihit_kvm_mitigation); =20 /* Default mitigation for L1TF-affected CPUs */ enum l1tf_mitigations l1tf_mitigation __ro_after_init =3D - IS_ENABLED(CONFIG_MITIGATION_L1TF) ? L1TF_MITIGATION_FLUSH : L1TF_MITIGAT= ION_OFF; + IS_ENABLED(CONFIG_MITIGATION_L1TF) ? L1TF_MITIGATION_AUTO : L1TF_MITIGATI= ON_OFF; #if IS_ENABLED(CONFIG_KVM_INTEL) EXPORT_SYMBOL_GPL(l1tf_mitigation); #endif @@ -2601,23 +2603,34 @@ static void override_cache_bits(struct cpuinfo_x86 = *c) } =20 static void __init l1tf_select_mitigation(void) +{ + if (!boot_cpu_has_bug(X86_BUG_L1TF) || cpu_mitigations_off()) { + l1tf_mitigation =3D L1TF_MITIGATION_OFF; + return; + } + + if (l1tf_mitigation =3D=3D L1TF_MITIGATION_AUTO) { + if (cpu_mitigations_auto_nosmt()) + l1tf_mitigation =3D L1TF_MITIGATION_FLUSH_NOSMT; + else + l1tf_mitigation =3D L1TF_MITIGATION_FLUSH; + } +} + +static void __init l1tf_apply_mitigation(void) { u64 half_pa; =20 if (!boot_cpu_has_bug(X86_BUG_L1TF)) return; =20 - if (cpu_mitigations_off()) - l1tf_mitigation =3D L1TF_MITIGATION_OFF; - else if (cpu_mitigations_auto_nosmt()) - l1tf_mitigation =3D L1TF_MITIGATION_FLUSH_NOSMT; - override_cache_bits(&boot_cpu_data); =20 switch (l1tf_mitigation) { case L1TF_MITIGATION_OFF: case L1TF_MITIGATION_FLUSH_NOWARN: case L1TF_MITIGATION_FLUSH: + case L1TF_MITIGATION_AUTO: break; case L1TF_MITIGATION_FLUSH_NOSMT: case L1TF_MITIGATION_FULL: diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 3dd9007ae685..bd61e88ba445 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -273,6 +273,7 @@ static int vmx_setup_l1d_flush(enum vmx_l1d_flush_state= l1tf) case L1TF_MITIGATION_OFF: l1tf =3D VMENTER_L1D_FLUSH_NEVER; break; + case L1TF_MITIGATION_AUTO: case L1TF_MITIGATION_FLUSH_NOWARN: case L1TF_MITIGATION_FLUSH: case L1TF_MITIGATION_FLUSH_NOSMT: @@ -7652,6 +7653,7 @@ int vmx_vm_init(struct kvm *kvm) case L1TF_MITIGATION_FLUSH_NOWARN: /* 'I explicitly don't care' is set */ break; + case L1TF_MITIGATION_AUTO: case L1TF_MITIGATION_FLUSH: case L1TF_MITIGATION_FLUSH_NOSMT: case L1TF_MITIGATION_FULL: --=20 2.34.1