From nobody Sun Oct 5 18:00:11 2025 Received: from NAM12-BN8-obe.outbound.protection.outlook.com (mail-bn8nam12on2079.outbound.protection.outlook.com [40.107.237.79]) (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 CFC052253A5; Wed, 30 Jul 2025 21:56:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=40.107.237.79 ARC-Seal: i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753912563; cv=fail; b=Ue25Jqyi8WqmzjUAHo309zjBy9n3UTXYZJIq//fPKUyx+tWlLSRaK+CCY1IPphV6uaFLspmaN2o/6Dp63Yyjs6lAfSpFiWjGgBrRFEpf35y0GkuNjfTpkLzA/ntY40NN8QoITYaw9fPdC4QhB/9o+xLoGxIGQ0/KNBhaBDiFzss= ARC-Message-Signature: i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753912563; c=relaxed/simple; bh=OcH9X7dq/I+HW23IiRDmWVmAruIfxwuNfvTYCGUZpvc=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=JAVZny9L0PQAXDvkC9mKaLFFdDForVeauJF0iUc/L7WjplbxsAVkNhfoaOOYcwLa0BWKKRA9RRMQkyRThaeE8/z1kZEp70nhVbOoBVfv/aT/48VQlI/uPzVnVa+hGzi8HYLD8yhoBVZja9LFMO1yBkJxsCgZenQdhFvNDw00FDE= 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=dWiDzrKa; arc=fail smtp.client-ip=40.107.237.79 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="dWiDzrKa" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=IWcAE+MkZYIxuBgIN6rtM/kCdewCu+K3FCxNXJ8j6b9F9CnbkhGPw+rUHs75yjreeprvFTrFPfjNgnJEDj0Z7cGPUcfjlLzptiduiU+Ki8TwVUu+M+eVqjFI+GXYMSvKKHVffA8r7/ImNsrhZdrBa1/EQNokeCYNDQL5VA8xRwiCt5RQ5wsa2S0Ktag/lznAxFCEj1492o+cGzTmrGYlItgSej1sXYPQ0emIahOx9hDXJWDhdE84kpeR1ThLx2enEBFmhR+IrKotpJHE/ShqfCNmG9SifoIAneMj6xOs7bxvDwvjzLPzP8Hsj30YMztzaC2cdSm62pcTpGzKsG+Eug== 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=UV/pvAIfGzSn8e8K9qgx+dRToXHMgz8oND1CxjcvJlM=; b=a3XpeR2zTXhh7Y8r9BGlMnAMX14J/QmPZDSnJrTIXJ5qcHYUxMbdD1+kzKo3HbEo+uMJxjaW2n08lCBHYOZYiJIm2/6FUQhzsHV3ZOWT+PCe9iIr4e6nfGrwKpmqsAAMMEUERSeZc124f2p/vUEDOT64uQfn6sQrYKxiYBo8wxermta0QXP6Qez6yNkYphAeEsybp6gEv8OZERiVq2GAGnsSnamCfRW/JtcBJXbQ4h0sl1A67l1VrN75/kEtxlZUoygAHKU5rS7/ZgY0nyOWk0IgsEG8RUh/VTh6gOvj07PS4+ok4rv4jR7yzpQpFW5uOjaABbiTepHltyvyknF05w== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass (sender ip is 165.204.84.17) smtp.rcpttodomain=8bytes.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=UV/pvAIfGzSn8e8K9qgx+dRToXHMgz8oND1CxjcvJlM=; b=dWiDzrKa9jeXohh8aLAbPt5vTXPLI/kubRIr+pbpPz4rVbfiZOzbZyWyiQpWEINyryQBdbTt1yJxU0ikEkVAhgOnyCzui6ekhJg+X7SI9395+U/Ct3fped/onHoMvHWMQo1jYgee7EgamM3fG1P/LfFGWx9NegCWN1eQvLBKL/0= Received: from BN1PR14CA0021.namprd14.prod.outlook.com (2603:10b6:408:e3::26) by IA0PR12MB8376.namprd12.prod.outlook.com (2603:10b6:208:40b::9) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.8964.26; Wed, 30 Jul 2025 21:55:57 +0000 Received: from BL6PEPF0001AB78.namprd02.prod.outlook.com (2603:10b6:408:e3:cafe::c1) by BN1PR14CA0021.outlook.office365.com (2603:10b6:408:e3::26) with Microsoft SMTP Server (version=TLS1_3, cipher=TLS_AES_256_GCM_SHA384) id 15.20.8989.12 via Frontend Transport; Wed, 30 Jul 2025 21:55:57 +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 BL6PEPF0001AB78.mail.protection.outlook.com (10.167.242.171) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.20.8989.10 via Frontend Transport; Wed, 30 Jul 2025 21:55:57 +0000 Received: from ethanolx7e2ehost.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; Wed, 30 Jul 2025 16:55:56 -0500 From: Ashish Kalra To: , , , , , CC: , , , , , , , , , , Subject: [PATCH v5 1/4] iommu/amd: Add support to remap/unmap IOMMU buffers for kdump Date: Wed, 30 Jul 2025 21:55:46 +0000 Message-ID: X-Mailer: git-send-email 2.34.1 In-Reply-To: References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable X-ClientProxiedBy: SATLEXMB03.amd.com (10.181.40.144) To SATLEXMB04.amd.com (10.181.40.145) X-EOPAttributedMessage: 0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: BL6PEPF0001AB78:EE_|IA0PR12MB8376:EE_ X-MS-Office365-Filtering-Correlation-Id: d0230620-6a6a-43d2-f1d4-08ddcfb3dd31 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|36860700013|1800799024|82310400026|7416014|376014|13003099007; X-Microsoft-Antispam-Message-Info: =?utf-8?B?WmxXRlBPZitRbENnUTNmMmJSbVd5U0RwUlRES0RkNkNOK0pGWUhCK21TS2RM?= =?utf-8?B?azFQaDJza3BmV3lFN0FzWThMaSthcFA5VEYrd24rUkpOSVpNZ0kweTBDSnp1?= =?utf-8?B?UEQzM0ZzWUV6c2haeDllSVVhbmEycC96UFFxOFQ3TzNlN2s3c0pzaldEY1V1?= =?utf-8?B?V2pPczNVc01HWUNtQWtwTVhXTWYvRXptUEhGRjBCaUl6RCtFdjIzY2oyZ3lW?= =?utf-8?B?WEJSVXh1a1pCeGxoVklseG8zU0ZDbUVaYzJWT0grRWh2ODBpaDBnamlENHhH?= =?utf-8?B?blhJL1crbXpSQms1Yks5bkE2NVNMWVVRRUwxdE1hLzNGK0hPalVETlpsREZZ?= =?utf-8?B?OXMvQS85ZlhMMzN1U2ZiQmUvcThjY2VBOUhUL05VOG9XYVVQaW83d0hCOVFD?= =?utf-8?B?YlE1eG5rVXNmQ0JaWkQ0bG9yQzhvOHdJcU9iVjBVZDZzblMrVzVuMitOYmo1?= =?utf-8?B?ajV0Rk53a1lmb0FoS2Z6UWpZTjdHUWtTZmRHVnRmcGhFNXFhamZvSjJhcVVD?= =?utf-8?B?RzUrTlJmUXBORDBSSHFZRURBMGJRQ2ljeUFKSmRqUmRRaHdCSGlDTGZoejM3?= =?utf-8?B?TG14UnVpbURScVkrU3pRTzcxd0EzbmNqVzRxUjJvbXNsZFBscWxsLzQzRHdj?= =?utf-8?B?MHZOUjlNTTVua2RBYU42Qm9rcWJNNnNsbXV6RzY5K2EwMkwvY2VVc0ZSL08z?= =?utf-8?B?dytWc1E1N3VQNXl0UTBac2REbDJSNW9DK1NUaVFnVlJHbnUwRzd1UXV0SE1m?= =?utf-8?B?UjBhWFhsOWhwSXVrZ09BRG45SmhMT1R4QkFKZllaZmxtdHFMUTRMZXNxT2dm?= =?utf-8?B?UFFmc3hKcndxNU81bUpSZCt3SklFbXB5R2N4ZGxNUlpnaHM5ZDU3UmsyNnFj?= =?utf-8?B?UjJmZHV4c0xUaGtqdWcveDFmOUh6THJDSFlZd09Ld3JHZHpoNzRBbjhTMFdQ?= =?utf-8?B?TmdWN2RBOUdqbm5jOCt4NE9rODFqUXkxaVBudy83a05JWmIxekMxRWZaRnBw?= =?utf-8?B?Q3RENnVLcVhNZnBWU1hKRjZ4ZHpBY3RCekVQaVBPTUtvenlrbi8zaUJLeWpL?= =?utf-8?B?QWZVS1NndGlVQVJyd3pJaW8reHhsajNTSlYxMFRGYWMvbW1sMUIxOEpJRmQr?= =?utf-8?B?aHphbjErczZhOTA5QmZGb0tmbVdQaTNtSXlFQ0pEMENpQjJRNk9ob2NselNr?= =?utf-8?B?S2dSalZXRXplbDZlRjFwTlM5dzNVMFRNSDI5RXNNSTY2ZjU3cWtEWHVTdlk2?= =?utf-8?B?Q1pvWWwvanZPekt0VWRPOUsvY3pzWE55WG15dFprQUdOeG1sOGFUM0tOalFG?= =?utf-8?B?dzJSakFmdnpmUUZBZktuVEpjNHFEODJxWHF5SE5KMTM3bmt6alR2N3pVdERa?= =?utf-8?B?bXp6WWF5ZERwa3R2eHd5MVAyZWhGRUM1ZUozS2oxUEVZYkxxTStNVndhUUFQ?= =?utf-8?B?MEQ2b3llS1NFYXFOYUpXWjBRY1lKN1REYjBOWmNUMXB3S1ZsYjE2cWF5emdD?= =?utf-8?B?ekZ0MlFKS3lybzMzL2c3TGh1UVN3YWlhMFEwNVVyRlhZQ0RFcVlCdXdsMVBy?= =?utf-8?B?YlhJOGo2bW5sUU92eGJDY0FjNFRUOUp0YzVRVFZIaDZMU253V2E2a2lYRlNl?= =?utf-8?B?d2JwNzdoRHJweXNLWnk1anRNNEsvQnZ6RmhOUEhuaFo1emdHT3Zja1FMRi9a?= =?utf-8?B?cHJOY1FWRU5iTHB6U3R4VFNGR1ZlRElKRW51MmliejN1WUc1c05IeWlacVVL?= =?utf-8?B?M3lCREh6Qno5SmJFR01RcEhlazlzV2dGaEQ2SjBNNXppbFEyN3JMdEt1UTdT?= =?utf-8?B?VjVnWmtHSFVHcjZXY2NKcTlsQjZYOSt0RFBCdnpqbWdrWU0xTjBIczJTNkJU?= =?utf-8?B?STFhVTlmTUQzRVdldlZZOEVnenJKekRYZDJCUU04L3Q4cVVBcnpLZkkxUVRK?= =?utf-8?B?M2Fza2psTEtIaW1MN203bC90WHNSenhPR015ejFaQk1pTjBFQjN6VVQwVitz?= =?utf-8?B?TmJ6UVd6Y3EzWHVjcFkxNHBkeVp3T2tob2pXZUFGZ0o5MXhYcW5NMWx2WHo5?= =?utf-8?B?KzRITmRubmF4cjRFU3FrZ2VFTUlQRW9sZnV5UT09?= 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)(36860700013)(1800799024)(82310400026)(7416014)(376014)(13003099007);DIR:OUT;SFP:1101; X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 30 Jul 2025 21:55:57.3173 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: d0230620-6a6a-43d2-f1d4-08ddcfb3dd31 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: BL6PEPF0001AB78.namprd02.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: IA0PR12MB8376 From: Ashish Kalra After a panic if SNP is enabled in the previous kernel then the kdump kernel boots with IOMMU SNP enforcement still enabled. IOMMU completion wait buffers (CWBs), command buffers and event buffer registers remain locked and exclusive to the previous kernel. Attempts to allocate and use new buffers in the kdump kernel fail, as hardware ignores writes to the locked MMIO registers as per AMD IOMMU spec Section 2.12.2.1. This results in repeated "Completion-Wait loop timed out" errors and a second kernel panic: "Kernel panic - not syncing: timer doesn't work through Interrupt-remapped IO-APIC" The list of MMIO registers locked and which ignore writes after failed SNP shutdown are mentioned in the AMD IOMMU specifications below: Section 2.12.2.1. https://docs.amd.com/v/u/en-US/48882_3.10_PUB Reuse the pages of the previous kernel for completion wait buffers, command buffers, event buffers and memremap them during kdump boot and essentially work with an already enabled IOMMU configuration and re-using the previous kernel=E2=80=99s data structures. Reusing of command buffers and event buffers is now done for kdump boot irrespective of SNP being enabled during kdump. Re-use of completion wait buffers is only done when SNP is enabled as the exclusion base register is used for the completion wait buffer (CWB) address only when SNP is enabled. Tested-by: Sairaj Kodilkar Signed-off-by: Ashish Kalra Reviewed-by: Vasant Hegde --- drivers/iommu/amd/amd_iommu_types.h | 5 + drivers/iommu/amd/init.c | 164 ++++++++++++++++++++++++++-- drivers/iommu/amd/iommu.c | 2 +- 3 files changed, 158 insertions(+), 13 deletions(-) diff --git a/drivers/iommu/amd/amd_iommu_types.h b/drivers/iommu/amd/amd_io= mmu_types.h index 5219d7ddfdaa..8a863cae99db 100644 --- a/drivers/iommu/amd/amd_iommu_types.h +++ b/drivers/iommu/amd/amd_iommu_types.h @@ -791,6 +791,11 @@ struct amd_iommu { u32 flags; volatile u64 *cmd_sem; atomic64_t cmd_sem_val; + /* + * Track physical address to directly use it in build_completion_wait() + * and avoid adding any special checks and handling for kdump. + */ + u64 cmd_sem_paddr; =20 #ifdef CONFIG_AMD_IOMMU_DEBUGFS /* DebugFS Info */ diff --git a/drivers/iommu/amd/init.c b/drivers/iommu/amd/init.c index 7b5af6176de9..aae1aa7723a5 100644 --- a/drivers/iommu/amd/init.c +++ b/drivers/iommu/amd/init.c @@ -710,6 +710,26 @@ static void __init free_alias_table(struct amd_iommu_p= ci_seg *pci_seg) pci_seg->alias_table =3D NULL; } =20 +static inline void *iommu_memremap(unsigned long paddr, size_t size) +{ + phys_addr_t phys; + + if (!paddr) + return NULL; + + /* + * Obtain true physical address in kdump kernel when SME is enabled. + * Currently, previous kernel with SME enabled and kdump kernel + * with SME support disabled is not supported. + */ + phys =3D __sme_clr(paddr); + + if (cc_platform_has(CC_ATTR_HOST_MEM_ENCRYPT)) + return (__force void *)ioremap_encrypted(phys, size); + else + return memremap(phys, size, MEMREMAP_WB); +} + /* * Allocates the command buffer. This buffer is per AMD IOMMU. We can * write commands to that buffer later and the IOMMU will execute them @@ -942,8 +962,103 @@ static int iommu_init_ga_log(struct amd_iommu *iommu) static int __init alloc_cwwb_sem(struct amd_iommu *iommu) { iommu->cmd_sem =3D iommu_alloc_4k_pages(iommu, GFP_KERNEL, 1); + if (!iommu->cmd_sem) + return -ENOMEM; + iommu->cmd_sem_paddr =3D iommu_virt_to_phys((void *)iommu->cmd_sem); + return 0; +} + +static int __init remap_event_buffer(struct amd_iommu *iommu) +{ + u64 paddr; + + pr_info_once("Re-using event buffer from the previous kernel\n"); + /* + * Read-back the event log base address register and apply + * PM_ADDR_MASK to obtain the event log base address. + */ + paddr =3D readq(iommu->mmio_base + MMIO_EVT_BUF_OFFSET) & PM_ADDR_MASK; + iommu->evt_buf =3D iommu_memremap(paddr, EVT_BUFFER_SIZE); =20 - return iommu->cmd_sem ? 0 : -ENOMEM; + return iommu->evt_buf ? 0 : -ENOMEM; +} + +static int __init remap_command_buffer(struct amd_iommu *iommu) +{ + u64 paddr; + + pr_info_once("Re-using command buffer from the previous kernel\n"); + /* + * Read-back the command buffer base address register and apply + * PM_ADDR_MASK to obtain the command buffer base address. + */ + paddr =3D readq(iommu->mmio_base + MMIO_CMD_BUF_OFFSET) & PM_ADDR_MASK; + iommu->cmd_buf =3D iommu_memremap(paddr, CMD_BUFFER_SIZE); + + return iommu->cmd_buf ? 0 : -ENOMEM; +} + +static int __init remap_or_alloc_cwwb_sem(struct amd_iommu *iommu) +{ + u64 paddr; + + if (check_feature(FEATURE_SNP)) { + /* + * When SNP is enabled, the exclusion base register is used for the + * completion wait buffer (CWB) address. Read and re-use it. + */ + pr_info_once("Re-using CWB buffers from the previous kernel\n"); + /* + * Read-back the exclusion base register and apply PM_ADDR_MASK + * to obtain the exclusion range base address. + */ + paddr =3D readq(iommu->mmio_base + MMIO_EXCL_BASE_OFFSET) & PM_ADDR_MASK; + iommu->cmd_sem =3D iommu_memremap(paddr, PAGE_SIZE); + if (!iommu->cmd_sem) + return -ENOMEM; + iommu->cmd_sem_paddr =3D paddr; + } else { + return alloc_cwwb_sem(iommu); + } + + return 0; +} + +static int __init alloc_iommu_buffers(struct amd_iommu *iommu) +{ + int ret; + + /* + * Reuse/Remap the previous kernel's allocated completion wait + * command and event buffers for kdump boot. + */ + if (is_kdump_kernel()) { + ret =3D remap_or_alloc_cwwb_sem(iommu); + if (ret) + return ret; + + ret =3D remap_command_buffer(iommu); + if (ret) + return ret; + + ret =3D remap_event_buffer(iommu); + if (ret) + return ret; + } else { + ret =3D alloc_cwwb_sem(iommu); + if (ret) + return ret; + + ret =3D alloc_command_buffer(iommu); + if (ret) + return ret; + + ret =3D alloc_event_buffer(iommu); + if (ret) + return ret; + } + + return 0; } =20 static void __init free_cwwb_sem(struct amd_iommu *iommu) @@ -951,6 +1066,38 @@ static void __init free_cwwb_sem(struct amd_iommu *io= mmu) if (iommu->cmd_sem) iommu_free_pages((void *)iommu->cmd_sem); } +static void __init unmap_cwwb_sem(struct amd_iommu *iommu) +{ + if (iommu->cmd_sem) { + if (check_feature(FEATURE_SNP)) + memunmap((void *)iommu->cmd_sem); + else + iommu_free_pages((void *)iommu->cmd_sem); + } +} + +static void __init unmap_command_buffer(struct amd_iommu *iommu) +{ + memunmap((void *)iommu->cmd_buf); +} + +static void __init unmap_event_buffer(struct amd_iommu *iommu) +{ + memunmap(iommu->evt_buf); +} + +static void __init free_iommu_buffers(struct amd_iommu *iommu) +{ + if (is_kdump_kernel()) { + unmap_cwwb_sem(iommu); + unmap_command_buffer(iommu); + unmap_event_buffer(iommu); + } else { + free_cwwb_sem(iommu); + free_command_buffer(iommu); + free_event_buffer(iommu); + } +} =20 static void iommu_enable_xt(struct amd_iommu *iommu) { @@ -1655,9 +1802,7 @@ static void __init free_sysfs(struct amd_iommu *iommu) static void __init free_iommu_one(struct amd_iommu *iommu) { free_sysfs(iommu); - free_cwwb_sem(iommu); - free_command_buffer(iommu); - free_event_buffer(iommu); + free_iommu_buffers(iommu); amd_iommu_free_ppr_log(iommu); free_ga_log(iommu); iommu_unmap_mmio_space(iommu); @@ -1821,14 +1966,9 @@ static int __init init_iommu_one_late(struct amd_iom= mu *iommu) { int ret; =20 - if (alloc_cwwb_sem(iommu)) - return -ENOMEM; - - if (alloc_command_buffer(iommu)) - return -ENOMEM; - - if (alloc_event_buffer(iommu)) - return -ENOMEM; + ret =3D alloc_iommu_buffers(iommu); + if (ret) + return ret; =20 iommu->int_enabled =3D false; =20 diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c index eb348c63a8d0..05a9ab3da1a3 100644 --- a/drivers/iommu/amd/iommu.c +++ b/drivers/iommu/amd/iommu.c @@ -1195,7 +1195,7 @@ static void build_completion_wait(struct iommu_cmd *c= md, struct amd_iommu *iommu, u64 data) { - u64 paddr =3D iommu_virt_to_phys((void *)iommu->cmd_sem); + u64 paddr =3D iommu->cmd_sem_paddr; =20 memset(cmd, 0, sizeof(*cmd)); cmd->data[0] =3D lower_32_bits(paddr) | CMD_COMPL_WAIT_STORE_MASK; --=20 2.34.1 From nobody Sun Oct 5 18:00:11 2025 Received: from NAM02-DM3-obe.outbound.protection.outlook.com (mail-dm3nam02on2052.outbound.protection.outlook.com [40.107.95.52]) (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 93CF12253A5; Wed, 30 Jul 2025 21:56:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=40.107.95.52 ARC-Seal: i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753912581; cv=fail; b=Vf+OJ/qinKlmjkXC/mfTkkjzkEnl382UImnv+p4wLfEinS71YuLpUNpIc2tZIDx4sNIhlh1nyvM13v8zQRTuffo8gNSpKI5PAuqE4PXodXvsHc5GC13OVasf2oVZUFseID55juQVSgE22GQYDxlHhR87wtc0mn28/ptbHEOapa8= ARC-Message-Signature: i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753912581; c=relaxed/simple; bh=EXw6VZVFPUUcn1knUuLGa1OAD06Gd5QzP8BUIHB4IV4=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=jY22ugzQWYsf9mVqPoIT1/fwnS+tWmdr6l5UKwCijNfhB7p+6nmTNmasArzmKnAjp680lLf2O2vs/lzZu8G4StlKyUnh+7jKmsZrqovnY/pujVZrQ2Xq70X3l2uZsoJshvFGzJSM/EFdkgMOpxsljGniP/OFEU+NXc9LFSgb7yQ= 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=oSd7mJZn; arc=fail smtp.client-ip=40.107.95.52 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="oSd7mJZn" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=WV2cLxbL/hbhQB/ia2ed22/IvHAwwf41IrxH9GjIiUN6b/DDfjoeUU8OMM2PMz6lEyjedCGk3YsRQJVod8LDmNpwra2idH6SPV7cv8uE0NiDLNocCo2LnW4SlytFGbvMUrb1W0lP4zP8QBNXynpvnRQQEONv9vOLbaFDi/fZCcDPf89OxoOgCKCIXAy4GB8FrNIuskjWY43K5nL79rHs7GLRLc8/x4w0WpFXCFjDERQ6fRhzzGdWjOAWZ5EmaZDwYfungXc8fthqdTB/WICaruNikFTXRaq6ohhfsF21w8TCLGfTLEqwvbRQHL7Bm9vYd+MYmY9x4SpjXQAK2ENI7g== 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=mjpIzl6GTk6LVgR9xegp4Iez4yKdbg3+go6bGePvKLU=; b=G/unb8t/q/ZPCi5N7uXEZoYw2qW3HTFxbgApXzBqtD9mm8M22OnYE7wJdSdtR+vLK3ua/GmGp02rbLNuVkoyuHse4HzTK80d+ypcNm1LNRK3n7gL8ugOgN4O0V9hrs1qosJFOyvQQXASiKikbALmnCXvm1yYV4AfH/ZB+LNN9jBK6L5diHGT08ecRzNa+aV3Brv4tUNfH0SzZkRq5+3NaY/hYQwmhd1sgdl9ee2gMlqsk6GC42b7BOYg/JO//U5zLWbZtScfpzXW7deQGabAVOTkWmZFeQdpnN+gk7nGW/hMc/5nCniB/vudwvcFZTSW3zeJugeOTsyYkwFTxa50iA== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass (sender ip is 165.204.84.17) smtp.rcpttodomain=8bytes.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=mjpIzl6GTk6LVgR9xegp4Iez4yKdbg3+go6bGePvKLU=; b=oSd7mJZnFgjd1mc1g3haZ2HNK//LFBWjBQirRF9CSjABS1R05HgIQE6vewtNgThf8OoX7pDhhvJ9+ptI/OV3LJ4VfICUJ+a/5BSKWVmolAD5Iv8L68hDLSSIhbiYzjl8tW5R29JsxSQYrryax94CjDIkkSo6BLr59IIcjO48l2k= Received: from BN9PR03CA0543.namprd03.prod.outlook.com (2603:10b6:408:138::8) by DS5PPFD22966BE3.namprd12.prod.outlook.com (2603:10b6:f:fc00::662) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.8989.13; Wed, 30 Jul 2025 21:56:13 +0000 Received: from BL6PEPF0001AB71.namprd02.prod.outlook.com (2603:10b6:408:138:cafe::e4) by BN9PR03CA0543.outlook.office365.com (2603:10b6:408:138::8) with Microsoft SMTP Server (version=TLS1_3, cipher=TLS_AES_256_GCM_SHA384) id 15.20.8943.29 via Frontend Transport; Wed, 30 Jul 2025 21:56:13 +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 BL6PEPF0001AB71.mail.protection.outlook.com (10.167.242.164) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.20.8989.10 via Frontend Transport; Wed, 30 Jul 2025 21:56:13 +0000 Received: from ethanolx7e2ehost.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; Wed, 30 Jul 2025 16:56:12 -0500 From: Ashish Kalra To: , , , , , CC: , , , , , , , , , , Subject: [PATCH v5 2/4] iommu/amd: Reuse device table for kdump Date: Wed, 30 Jul 2025 21:56:03 +0000 Message-ID: <5ad4c4525a2fd673cabcc763f0ccdb9b3595aaf4.1753911773.git.ashish.kalra@amd.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: References: 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: SATLEXMB03.amd.com (10.181.40.144) To SATLEXMB04.amd.com (10.181.40.145) X-EOPAttributedMessage: 0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: BL6PEPF0001AB71:EE_|DS5PPFD22966BE3:EE_ X-MS-Office365-Filtering-Correlation-Id: 452811cb-9bb9-4633-681d-08ddcfb3e6bb X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|82310400026|36860700013|1800799024|376014|7416014; X-Microsoft-Antispam-Message-Info: =?us-ascii?Q?4uVJ2FiNSkBt7JhN2F5G/e5KQ1s2eRIDjqIOBHGPCmVs4sYX7jgPB7viDTXu?= =?us-ascii?Q?NkTJvVQzpImzxOX19DrzC6V84d35Zk6IZ8NMXr7YKQMgvua4MLLHmu9PEQSE?= =?us-ascii?Q?lJWEugfmq5m1J6fYCu9vcs+q3o13V6+d+SaltRN/vNQlbNchID4lj7wy3qdQ?= =?us-ascii?Q?+8zB9uk4WvjIeg5DTQ+gL082T09kUiT8NVfYjpJrxrx466rZQHJqxRHwk+BL?= =?us-ascii?Q?CASWVPL6+7Z0ZA9g1VeGiQx1wFwsXSrC7L15Rg6j3r6fF7oaBlb523VqG16C?= =?us-ascii?Q?E578JQiMQgdeX58pRS0B7UJohD3+UmhSSilrkola/ex18q30RBDu7MY/DEnn?= =?us-ascii?Q?bxF6Jk4ixP4oFkfViHBOapUWvdjbvS+jXGuoBb3hxtgemmCtWv8p4jzianPP?= =?us-ascii?Q?ZN05Q2Awwe7PmBHW1ry3xlCAlhWOz74JrfFUgiW8p+zCkZZq73Prv5wkjeLj?= =?us-ascii?Q?E6obWzrCYBM7WlLkiSQuMpcG63zaSK+RAcHmIfaecjVR69Q6w22cwXPJwF5N?= =?us-ascii?Q?wJ8hWh/WHbIrNzXFgqi+/vRQIaWizZVSPw2JuMSn0FKXUt8HUR3ZV62tS4Zg?= =?us-ascii?Q?e1WCua+hyxlWGV1z98BZnEbCS6HX/dljFR2VEWWVfVdgBSrh/F7Sv18Xf1v7?= =?us-ascii?Q?LpFiIHaDe5OOvfDdsccMtiRgpcrh+3snJa+xCRlgaNhWb/S1iVztKoeE350o?= =?us-ascii?Q?SVt0uwbII359sSCbS/jzyGIn+hERdgjeasagroW+HJcWZsCoORo6+pfosvY6?= =?us-ascii?Q?zsJ4hkS94jbGJbAYGNuN17JVhdjl9EJseVX9sRvw9M98aV3RXV+ABYnlGgDs?= =?us-ascii?Q?069aEcRrI+CUH+dyEr8Dh/FoJNrw4GFAQBz9+wx0aF89RasTxJ/eTZtkR6ks?= =?us-ascii?Q?7ewuMme7AeiASJOoNzT6INB8yR5sMvw/ScORtzNpOBk5LG2dwztTQfAn2Qa0?= =?us-ascii?Q?aJLfqlXKSbGf1v8cEXsj/UiFDj9UrZfOhzV+5wYGc6w5qlZno6J90a8ZLGzw?= =?us-ascii?Q?85E27Cvqhpb9UnieGxrArNsUQ00t6HxLDUxfPMUi7qCzjPPQfYgboLN6Lod4?= =?us-ascii?Q?YumDPH8Rg7POHbOOgjeysbGKpr7ye5pjOcg4fo6KONBf6iCw8XDIs6vUb8h7?= =?us-ascii?Q?dRFfCqQqb7RDxkXpPb9db66uvyw7o9vE27kaugxpA0vrlwi7xsqSxO2iEAGI?= =?us-ascii?Q?3NZ5ZFiWvVL7xGJyC7QoqDDsm8nxN38QcrnfEO6IO4WMTiKUxF99vIYOEzk9?= =?us-ascii?Q?ZrDaGtletbPEFWAhpJot0oDycExfw8n0489ALSdYHFKnSok5DyKP0nekHXrV?= =?us-ascii?Q?ZB/X1rqU9dUk2Ab8KjuM2hBkd1xyDep0jVb7iIb9F3+A2tPRksaoy0E3lv7o?= =?us-ascii?Q?TQMB8lQRT5PZ1wrF1qnyku/QwOHx+NZLXcyZ9RdTiK1zhXI858lLP+VQldRz?= =?us-ascii?Q?pQXxPAmcdhX5NSsnpfqIXtKySD+Jb7dMDcdbvGNmG4KOYCCoXs00WPTN0jBb?= =?us-ascii?Q?Bkse1NnvKDPgqfmfdFFqmJup/AXYHiypNhhe?= 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)(36860700013)(1800799024)(376014)(7416014);DIR:OUT;SFP:1101; X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 30 Jul 2025 21:56:13.3159 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: 452811cb-9bb9-4633-681d-08ddcfb3e6bb 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: BL6PEPF0001AB71.namprd02.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: DS5PPFD22966BE3 Content-Type: text/plain; charset="utf-8" From: Ashish Kalra After a panic if SNP is enabled in the previous kernel then the kdump kernel boots with IOMMU SNP enforcement still enabled. IOMMU device table register is locked and exclusive to the previous kernel. Attempts to copy old device table from the previous kernel fails in kdump kernel as hardware ignores writes to the locked device table base address register as per AMD IOMMU spec Section 2.12.2.1. This results in repeated "Completion-Wait loop timed out" errors and a second kernel panic: "Kernel panic - not syncing: timer doesn't work through Interrupt-remapped IO-APIC". Reuse device table instead of copying device table in case of kdump boot and remove all copying device table code. =20 Tested-by: Sairaj Kodilkar Signed-off-by: Ashish Kalra Reviewed-by: Vasant Hegde --- drivers/iommu/amd/init.c | 106 +++++++++++++-------------------------- 1 file changed, 36 insertions(+), 70 deletions(-) diff --git a/drivers/iommu/amd/init.c b/drivers/iommu/amd/init.c index aae1aa7723a5..05d9c1764883 100644 --- a/drivers/iommu/amd/init.c +++ b/drivers/iommu/amd/init.c @@ -406,6 +406,9 @@ static void iommu_set_device_table(struct amd_iommu *io= mmu) =20 BUG_ON(iommu->mmio_base =3D=3D NULL); =20 + if (is_kdump_kernel()) + return; + entry =3D iommu_virt_to_phys(dev_table); entry |=3D (dev_table_size >> 12) - 1; memcpy_toio(iommu->mmio_base + MMIO_DEV_TABLE_OFFSET, @@ -646,7 +649,10 @@ static inline int __init alloc_dev_table(struct amd_io= mmu_pci_seg *pci_seg) =20 static inline void free_dev_table(struct amd_iommu_pci_seg *pci_seg) { - iommu_free_pages(pci_seg->dev_table); + if (is_kdump_kernel()) + memunmap((void *)pci_seg->dev_table); + else + iommu_free_pages(pci_seg->dev_table); pci_seg->dev_table =3D NULL; } =20 @@ -1129,15 +1135,12 @@ static void set_dte_bit(struct dev_table_entry *dte= , u8 bit) dte->data[i] |=3D (1UL << _bit); } =20 -static bool __copy_device_table(struct amd_iommu *iommu) +static bool __reuse_device_table(struct amd_iommu *iommu) { - u64 int_ctl, int_tab_len, entry =3D 0; struct amd_iommu_pci_seg *pci_seg =3D iommu->pci_seg; - struct dev_table_entry *old_devtb =3D NULL; - u32 lo, hi, devid, old_devtb_size; + u32 lo, hi, old_devtb_size; phys_addr_t old_devtb_phys; - u16 dom_id, dte_v, irq_v; - u64 tmp; + u64 entry; =20 /* Each IOMMU use separate device table with the same size */ lo =3D readl(iommu->mmio_base + MMIO_DEV_TABLE_OFFSET); @@ -1162,66 +1165,22 @@ static bool __copy_device_table(struct amd_iommu *i= ommu) pr_err("The address of old device table is above 4G, not trustworthy!\n"= ); return false; } - old_devtb =3D (cc_platform_has(CC_ATTR_HOST_MEM_ENCRYPT) && is_kdump_kern= el()) - ? (__force void *)ioremap_encrypted(old_devtb_phys, - pci_seg->dev_table_size) - : memremap(old_devtb_phys, pci_seg->dev_table_size, MEMREMAP_WB); - - if (!old_devtb) - return false; =20 - pci_seg->old_dev_tbl_cpy =3D iommu_alloc_pages_sz( - GFP_KERNEL | GFP_DMA32, pci_seg->dev_table_size); + /* + * IOMMU Device Table Base Address MMIO register is locked + * if SNP is enabled during kdump, reuse the previous kernel's + * device table. + */ + pci_seg->old_dev_tbl_cpy =3D iommu_memremap(old_devtb_phys, pci_seg->dev_= table_size); if (pci_seg->old_dev_tbl_cpy =3D=3D NULL) { - pr_err("Failed to allocate memory for copying old device table!\n"); - memunmap(old_devtb); + pr_err("Failed to remap memory for reusing old device table!\n"); return false; } =20 - for (devid =3D 0; devid <=3D pci_seg->last_bdf; ++devid) { - pci_seg->old_dev_tbl_cpy[devid] =3D old_devtb[devid]; - dom_id =3D old_devtb[devid].data[1] & DEV_DOMID_MASK; - dte_v =3D old_devtb[devid].data[0] & DTE_FLAG_V; - - if (dte_v && dom_id) { - pci_seg->old_dev_tbl_cpy[devid].data[0] =3D old_devtb[devid].data[0]; - pci_seg->old_dev_tbl_cpy[devid].data[1] =3D old_devtb[devid].data[1]; - /* Reserve the Domain IDs used by previous kernel */ - if (ida_alloc_range(&pdom_ids, dom_id, dom_id, GFP_ATOMIC) !=3D dom_id)= { - pr_err("Failed to reserve domain ID 0x%x\n", dom_id); - memunmap(old_devtb); - return false; - } - /* If gcr3 table existed, mask it out */ - if (old_devtb[devid].data[0] & DTE_FLAG_GV) { - tmp =3D (DTE_GCR3_30_15 | DTE_GCR3_51_31); - pci_seg->old_dev_tbl_cpy[devid].data[1] &=3D ~tmp; - tmp =3D (DTE_GCR3_14_12 | DTE_FLAG_GV); - pci_seg->old_dev_tbl_cpy[devid].data[0] &=3D ~tmp; - } - } - - irq_v =3D old_devtb[devid].data[2] & DTE_IRQ_REMAP_ENABLE; - int_ctl =3D old_devtb[devid].data[2] & DTE_IRQ_REMAP_INTCTL_MASK; - int_tab_len =3D old_devtb[devid].data[2] & DTE_INTTABLEN_MASK; - if (irq_v && (int_ctl || int_tab_len)) { - if ((int_ctl !=3D DTE_IRQ_REMAP_INTCTL) || - (int_tab_len !=3D DTE_INTTABLEN_512 && - int_tab_len !=3D DTE_INTTABLEN_2K)) { - pr_err("Wrong old irq remapping flag: %#x\n", devid); - memunmap(old_devtb); - return false; - } - - pci_seg->old_dev_tbl_cpy[devid].data[2] =3D old_devtb[devid].data[2]; - } - } - memunmap(old_devtb); - return true; } =20 -static bool copy_device_table(void) +static bool reuse_device_table(void) { struct amd_iommu *iommu; struct amd_iommu_pci_seg *pci_seg; @@ -1229,17 +1188,17 @@ static bool copy_device_table(void) if (!amd_iommu_pre_enabled) return false; =20 - pr_warn("Translation is already enabled - trying to copy translation stru= ctures\n"); + pr_warn("Translation is already enabled - trying to reuse translation str= uctures\n"); =20 /* * All IOMMUs within PCI segment shares common device table. - * Hence copy device table only once per PCI segment. + * Hence reuse device table only once per PCI segment. */ for_each_pci_segment(pci_seg) { for_each_iommu(iommu) { if (pci_seg->id !=3D iommu->pci_seg->id) continue; - if (!__copy_device_table(iommu)) + if (!__reuse_device_table(iommu)) return false; break; } @@ -2918,8 +2877,8 @@ static void early_enable_iommu(struct amd_iommu *iomm= u) * This function finally enables all IOMMUs found in the system after * they have been initialized. * - * Or if in kdump kernel and IOMMUs are all pre-enabled, try to copy - * the old content of device table entries. Not this case or copy failed, + * Or if in kdump kernel and IOMMUs are all pre-enabled, try to reuse + * the old content of device table entries. Not this case or reuse failed, * just continue as normal kernel does. */ static void early_enable_iommus(void) @@ -2927,18 +2886,25 @@ static void early_enable_iommus(void) struct amd_iommu *iommu; struct amd_iommu_pci_seg *pci_seg; =20 - if (!copy_device_table()) { + if (!reuse_device_table()) { /* - * If come here because of failure in copying device table from old + * If come here because of failure in reusing device table from old * kernel with all IOMMUs enabled, print error message and try to * free allocated old_dev_tbl_cpy. */ - if (amd_iommu_pre_enabled) - pr_err("Failed to copy DEV table from previous kernel.\n"); + if (amd_iommu_pre_enabled) { + pr_err("Failed to reuse DEV table from previous kernel.\n"); + /* + * Bail out early if unable to remap/reuse DEV table from + * previous kernel if SNP enabled as IOMMU commands will + * time out without DEV table and cause kdump boot panic. + */ + BUG_ON(check_feature(FEATURE_SNP)); + } =20 for_each_pci_segment(pci_seg) { if (pci_seg->old_dev_tbl_cpy !=3D NULL) { - iommu_free_pages(pci_seg->old_dev_tbl_cpy); + memunmap((void *)pci_seg->old_dev_tbl_cpy); pci_seg->old_dev_tbl_cpy =3D NULL; } } @@ -2948,7 +2914,7 @@ static void early_enable_iommus(void) early_enable_iommu(iommu); } } else { - pr_info("Copied DEV table from previous kernel.\n"); + pr_info("Reused DEV table from previous kernel.\n"); =20 for_each_pci_segment(pci_seg) { iommu_free_pages(pci_seg->dev_table); --=20 2.34.1 From nobody Sun Oct 5 18:00:11 2025 Received: from NAM10-BN7-obe.outbound.protection.outlook.com (mail-bn7nam10on2049.outbound.protection.outlook.com [40.107.92.49]) (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 C667D2253FE; Wed, 30 Jul 2025 21:56:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=40.107.92.49 ARC-Seal: i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753912601; cv=fail; b=ZMkKKjh19URcgiwbrTKZoRiMiIcoAdeTtaWJLT++oX31Sfm8qDDFZai4MQo1WK28B2gimoxQj/8tSJincpbJ4j46rYfL+JIhaPSQoecuu29XhFs4HyGQMwN5tT6JeOb7wh1amdEW9HJ0X+POk7/nM4J4Xj0tYtocrFiFiLE2AS0= ARC-Message-Signature: i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753912601; c=relaxed/simple; bh=zAowIoaqt+tdF/GEqGWn+VlfRq5YA1Ze4y7Ixx8UqM0=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=nJ3uNd0dZ6ei5RqQl4r7p0pSoZyC7+ox8quj3q8YVyerVwh+SPQnf0TWHOGt7Eptoh1c1FCOBTqkyXZ9BW2KmuOVKew5bFKunIV19DDiKIZw/HPxoJoxKGFZxKvk2KmK76N6C1s1TxGvWRopwBovdU76Xaxrj+1Pjy3SRbzJz5Q= 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=37CUkCVw; arc=fail smtp.client-ip=40.107.92.49 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="37CUkCVw" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=IYGktKY4H+Faacd24QjB2i1MQWpMnPfV+AcX/CE3JDc5CIJen79qXoTxmu1dw/c7jGWwVovZgMMWFpYX3EJ0uV7aDB62MWI9qSQIJOMe6daZqiyg86ZUgerKbca/LB+AbTbAUsB4p0XVtpmMY/VNBgWUDNVZxuNz1Py1vWoOooO2vSg7QOd7d5RoH1S+IEpi4+CJ7Jql2w5zaKpJxEBu1uHser4BATgYp5r2y4q8qwQ/z7MMsXhOG4/goRkfb3Q3RVk6A2IK9ibrwkiBYH9lwZDYdMIW3ml4GW+crswNSd0WvyvU4iyMxcHxPHH6zcw3LdIvq3FXJZJ9dRWO65ZwqQ== 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=jEP0xQSiAuu1Cn7QtSnps5Slla6O9boP5vbIvIbzVQ4=; b=zVJIJKYhz1XtQeAzyV2MtO65/dS/v+JaR0zcxnnyeMVBOKGhlg3zRft9x0UDyWdprU4CID+0HxUemqSJAtAQhVzs3My/ordnhzLOUQv2p2opS5C/wtVsUslr+sXju5WTRmiVTStBqkojZAulbNsfAKanu5mEU4+WE71cWOW8v/nCxGJLMb2hs046DGKOG3M2OWSVElpyr9/IpKY6iXE42VyxTDavV/F+zCwu8nwviOSAitBNacktUHyzq4Ugo9oovd359K7S5RYKh6X/3GaPxdpvxbCYejoEZeFrJv5NVvgO1xzr9WUx7eBxdaSig4biXV/eMAlsTHvPKFQyJgAC9A== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass (sender ip is 165.204.84.17) smtp.rcpttodomain=8bytes.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=jEP0xQSiAuu1Cn7QtSnps5Slla6O9boP5vbIvIbzVQ4=; b=37CUkCVwxj3hNvx2ac+/jr1QTn11hmov6BObbxPymDBa55hfVsRrE7E7+qXVQgjA4Zh1rF8hwbs+K0E/rGIvJiOl+LvEzxXIxOo8h2mu7+zACx+0s/14KM3EHtCO88IfuaM4DbARjo0QFXms/1N69f8zxS1gg8UWS0UNxNPIQZg= Received: from BN1PR14CA0027.namprd14.prod.outlook.com (2603:10b6:408:e3::32) by CH2PR12MB4312.namprd12.prod.outlook.com (2603:10b6:610:af::14) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.8964.25; Wed, 30 Jul 2025 21:56:35 +0000 Received: from BL6PEPF0001AB78.namprd02.prod.outlook.com (2603:10b6:408:e3:cafe::71) by BN1PR14CA0027.outlook.office365.com (2603:10b6:408:e3::32) with Microsoft SMTP Server (version=TLS1_3, cipher=TLS_AES_256_GCM_SHA384) id 15.20.8989.12 via Frontend Transport; Wed, 30 Jul 2025 21:56:34 +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 BL6PEPF0001AB78.mail.protection.outlook.com (10.167.242.171) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.20.8989.10 via Frontend Transport; Wed, 30 Jul 2025 21:56:34 +0000 Received: from ethanolx7e2ehost.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; Wed, 30 Jul 2025 16:56:33 -0500 From: Ashish Kalra To: , , , , , CC: , , , , , , , , , , Subject: [PATCH v5 3/4] crypto: ccp: Skip SEV and SNP INIT for kdump boot Date: Wed, 30 Jul 2025 21:56:24 +0000 Message-ID: <71e80dca138ed59bd2a948d7b79c01c30515d789.1753911773.git.ashish.kalra@amd.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: References: 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: SATLEXMB03.amd.com (10.181.40.144) To SATLEXMB04.amd.com (10.181.40.145) X-EOPAttributedMessage: 0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: BL6PEPF0001AB78:EE_|CH2PR12MB4312:EE_ X-MS-Office365-Filtering-Correlation-Id: e7e9923e-4ad4-4971-d29f-08ddcfb3f384 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|36860700013|1800799024|82310400026|7416014|376014; X-Microsoft-Antispam-Message-Info: =?us-ascii?Q?IXizqRY1EhAJG0rCVBaArstRYbgJPWRa5g2SflTSl4LU5pY9dHtpwRUI9RAE?= =?us-ascii?Q?uYvjr5Wsg5E7e84fc3rIwN7Osvhtq9BjD6VDM8b4Lyiq3G5dtNb0hUK/mbBA?= =?us-ascii?Q?VFpyqLZRP6f9GvdsnBDIA3o3jayrwWG/vI1LBraFLL4qpvcWZIQk56tmXOHV?= =?us-ascii?Q?LPIJDQetdaHF1GgkXh48fnhbiWh+VoQhnUGeMyTMlHBBYPlKNLqgFCavIME+?= =?us-ascii?Q?/kxLjNd0QPH9nv9ljHt0OFjdzc7zixtwygd8/4kXr6gCQxEpRAplbvsTV77e?= =?us-ascii?Q?1sjmcBdoq1drhIfKcacieyKTIhbsuDSpe29mLVsnMxIdeS2pd4RyqYeiGfP8?= =?us-ascii?Q?/OpGt4IqYA4NXyQRNXcXEZ1VothaKsg6yhd7CbuCM+Mbx94en4D5EyXgxhKK?= =?us-ascii?Q?QLFecp9CfT8U8uyoh9HX7nTny/etDmet2DiwExjGHOzQ71+diGMiO01d8kgN?= =?us-ascii?Q?1QzMAWS6oL75LzVUsrtFtzKurH7fYYNhB/hQjfmE0eNMHJ3nRVJmnEexUsFe?= =?us-ascii?Q?Q67pqX1/8NZHCKDJoRSIzsWSOHNAPffq+egd6tzjqV0eJNSMhYJvrA7c/fMC?= =?us-ascii?Q?jPMmBbxpFx4I0b6ulvEz/jyQJS0+BVnjDLbv3sqJogYUluYBEDKZVbte5uHA?= =?us-ascii?Q?0WWQJiyo9CQyDIGHX1EYCsSQ2KUO98HnS3c1SgVVRrYB4LzjHudjeKQ8wxle?= =?us-ascii?Q?u/P7fe9kAId2qF9DksVVk9BDSnRfB0j2QeKD+r9SmryFWFNXc5pSlGfk8HrF?= =?us-ascii?Q?B0hOArJT8KJOahzIlMocp6YcqgWwqXFN4AIwI3I4EWiwC9LMt8XmOhOhYov8?= =?us-ascii?Q?OBR5j+Zhp/QNImidrWZIlwA3AVwtbRsY7FDuRDjxUhMgfJZQAgR5VnCa6kCS?= =?us-ascii?Q?PUzLQNDNIMusWzgORmDQUKjHFnPW6o3jqgzeeBuFfb5oNb9deOGvZkWmz/Ha?= =?us-ascii?Q?Nmypj7L7o+6OL7MLOozZLxIiJZD6Z1kp1gIPz4nVQFEZzJk8Hq3CnTH9Bz9W?= =?us-ascii?Q?wGyD5k+ax0mf00/FbSFfDIN8znzD5hO4kXrL4ZMlop+DHll3HwhTFKpqsP1l?= =?us-ascii?Q?ndG8AN+gEfKwWnaAbtlzzNoheeEGfpO7wYg1Xiv+lIufDgGazp9y46lv4SXs?= =?us-ascii?Q?0y3XjDvpXKBauqmUsAn8oHUElzmKQ1nnFGZXe/zMxS5rDZ68tuluDLwrh33i?= =?us-ascii?Q?kF4ycxT1b/3OlW4q62qwWJ+UzHsxGsSLcJHPDQAymAWpJVBp9R4K/QJgi7Cf?= =?us-ascii?Q?eyg1ycKEJtlMNPKhXWw6/0y9eLEDwi8h2AyvQFfxCZZPfa73Zvtarqm32rXF?= =?us-ascii?Q?JSzvMXX4zeQTz1p94rS9kBBihfUTlR7HzWzuWO9nSy1ivBq+ollUW9a7m8WU?= =?us-ascii?Q?b+ciiy+fdqDpSAzSBsm3Rkb098CrLtmtkT2Zo4DMN77wd9mL0/xeZikRyncX?= =?us-ascii?Q?nIgNnFuHcccYAFagp/8e8QGyBFCItCnJ/RbnsieoPCD47ghctrIoV+0oUb+y?= =?us-ascii?Q?fpveX65xVGZovtfV7tV5AYkWufpc789rrpqn?= 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)(36860700013)(1800799024)(82310400026)(7416014)(376014);DIR:OUT;SFP:1101; X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 30 Jul 2025 21:56:34.7696 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: e7e9923e-4ad4-4971-d29f-08ddcfb3f384 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: BL6PEPF0001AB78.namprd02.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: CH2PR12MB4312 Content-Type: text/plain; charset="utf-8" From: Ashish Kalra If SNP is enabled and initialized in the previous kernel then SNP is already initialized for kdump boot and attempting SNP INIT again during kdump boot causes SNP INIT failure and eventually leads to IOMMU failures. For SEV avoid SEV INIT failure warnings during kdump boot if SEV is enabled and initialized in the previous kernel. Skip SNP and SEV INIT if doing kdump boot. Tested-by: Sairaj Kodilkar Signed-off-by: Ashish Kalra --- drivers/crypto/ccp/sev-dev.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c index e058ba027792..c204831ca4a6 100644 --- a/drivers/crypto/ccp/sev-dev.c +++ b/drivers/crypto/ccp/sev-dev.c @@ -28,6 +28,7 @@ #include #include #include +#include =20 #include #include @@ -1345,6 +1346,13 @@ static int _sev_platform_init_locked(struct sev_plat= form_init_args *args) if (!psp_master || !psp_master->sev_data) return -ENODEV; =20 + /* + * Skip SNP/SEV INIT for kdump boot as SEV/SNP is already initialized + * in previous kernel if SEV/SNP is enabled. + */ + if (is_kdump_kernel()) + return 0; + sev =3D psp_master->sev_data; =20 if (sev->state =3D=3D SEV_STATE_INIT) --=20 2.34.1 From nobody Sun Oct 5 18:00:11 2025 Received: from NAM11-DM6-obe.outbound.protection.outlook.com (mail-dm6nam11on2045.outbound.protection.outlook.com [40.107.223.45]) (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 2E1512253A5; Wed, 30 Jul 2025 21:56:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=40.107.223.45 ARC-Seal: i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753912618; cv=fail; b=hoExGDbLQm2lp7w3U4ZSh4KnetysYvk1CnLMDF0F8+QfmiwnBvEzt9FNKCDymZrVBrfhMo8+SoaZj4fT+fXoglrthYZiSgpcpRMMr0sDsmTfj8vlWCBbysJR3ycj6/CcqvQe73w6rPMTLfy6Lx1jxTzvIIuA9CWggq++1NV4RtU= ARC-Message-Signature: i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753912618; c=relaxed/simple; bh=jD80cfeyDdfMkUOf12qhy4DK91Ob+1Sr40vtozTC3hg=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=I04t3M7jAC7whCNlEl9VstiB/JIAunhMqnXTbDfVY2KcUIbvR27u1/1LpsI29oI/2mz2poPaTzB2akoUFQGbQIh6fVaPS1FJVASJ/aYlTdKR53wrVMr7tJuSUC8EapbwW5p2Lc3ViIsKx5+Gd+XDrEEleq+8J0K6dAd7Y0wCrdw= 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=tmSYqtMr; arc=fail smtp.client-ip=40.107.223.45 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="tmSYqtMr" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=F6V3DeQ2+PhZoGYgn63ZO8ux3p0n/Sb/TRyonsn39D+si4EBNAasLIsy6D4QJRhuyFrRMQwX08bUMHQ8HSIhKm9xbBrq3yeIZ+0giU8/gqSSZmtJKzNSrB+8y2ChZWW+nbzSMG3dhLVeMwoEhOhxpyIDz0mOMfP9ZJpwNg6w/YajXq7Fj2FSyklxDPRNjA4GRNJNxGzaY80qGvrcZ/RFj+sNxCxbeuYtWQ8LD1os5QkquMpH1e/rh0CQiBzzoZiTVfhgD0gMWWHUeaRbOKGHs92CKtod3C517mkZFq5fZnaTheQ6zJhJbvxIT8VhLfiTfopVwqz4BvmXqmmzH+WKfA== 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=lEx0hoEubJC858v5cvGzNdq9jtTc+gVAF7L8ksbVhB8=; b=Vm8HtQEFn83mFVgLnJQvOprJvxNWofAOsFEBOCKXk4kr7KyxsxuNbbsz6Kwl9CqhD7KFKnFbRS0GhaE+5aEtJxJzM+irJnsfRg4jp2xQU3EWTsgrs2KnxG52bEumKMaGllpja6G4UT5LKIuUkxc2lIcwuHTjEgrJs+USHpmtZZrAOJaLMT8a1ac7z98pTvJMQZEzChe4myegyiptkNb8CUtYWWWbbGQQtoLdX7GDifXlpS581k60mhYAhK8AEWISXbX6OaJBUl0fxjMeAJwKlMy7vSHjV5u9XxRRM4ePor0mty/afnCLUvYmZNteAZeAZA4CybJ/G2Gicx8+9y4ppw== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass (sender ip is 165.204.84.17) smtp.rcpttodomain=8bytes.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=lEx0hoEubJC858v5cvGzNdq9jtTc+gVAF7L8ksbVhB8=; b=tmSYqtMr6qseWy9plFF/hY+ECBruR08ZkOKHgge12ifO06AW2TjqZVQDrVlzN0/u07TQxRjAykIuYRA/vFk5dWy4VQOsBhA/sg1Ew9lQpZxJoBVugZIGmfUd95umcOfHumWvdMK0dgXkipiXw5lh1xqcGAgnNrHYvLZzXjO0lnY= Received: from BN1PR14CA0018.namprd14.prod.outlook.com (2603:10b6:408:e3::23) by SA1PR12MB7444.namprd12.prod.outlook.com (2603:10b6:806:2b3::16) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.8989.11; Wed, 30 Jul 2025 21:56:52 +0000 Received: from BL6PEPF0001AB78.namprd02.prod.outlook.com (2603:10b6:408:e3:cafe::c6) by BN1PR14CA0018.outlook.office365.com (2603:10b6:408:e3::23) with Microsoft SMTP Server (version=TLS1_3, cipher=TLS_AES_256_GCM_SHA384) id 15.20.8989.11 via Frontend Transport; Wed, 30 Jul 2025 21:56:50 +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 BL6PEPF0001AB78.mail.protection.outlook.com (10.167.242.171) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.20.8989.10 via Frontend Transport; Wed, 30 Jul 2025 21:56:50 +0000 Received: from ethanolx7e2ehost.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; Wed, 30 Jul 2025 16:56:49 -0500 From: Ashish Kalra To: , , , , , CC: , , , , , , , , , , Subject: [PATCH v5 4/4] iommu/amd: Skip enabling command/event buffers for kdump Date: Wed, 30 Jul 2025 21:56:39 +0000 Message-ID: X-Mailer: git-send-email 2.34.1 In-Reply-To: References: 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: SATLEXMB03.amd.com (10.181.40.144) To SATLEXMB04.amd.com (10.181.40.145) X-EOPAttributedMessage: 0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: BL6PEPF0001AB78:EE_|SA1PR12MB7444:EE_ X-MS-Office365-Filtering-Correlation-Id: 15def575-a883-4091-9e01-08ddcfb3fcb3 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|82310400026|36860700013|1800799024|7416014|376014; X-Microsoft-Antispam-Message-Info: =?us-ascii?Q?1sgl3UXkS3UF7bueEfjevyTYEk4PhYtBPyh+TQdKHnr4gmxxexnD35lzg4a7?= =?us-ascii?Q?0xKK3QiJOr4YXaAxsrNsY/7KETVRRQAOwQXeuyOh2vJ0PTktvfTjfv+EXeUp?= =?us-ascii?Q?pALQg3fu62JOZB37+ruiPq6iqi+Eq3zg0OM+WegczIJ4+syZ9WJhiv7eMEb7?= =?us-ascii?Q?qYB2PrPGz9TbfoNLBd4aoiE6Gm+bu/zQUECAelmzS3vVolTrDKPJ9Wp1x5YF?= =?us-ascii?Q?41MY9xWptJ1fK8E4aQLszMFT++sClJZviWR2fFTFa8lFSBA+ieGSZ4VM1rDE?= =?us-ascii?Q?X77pM087sbPAB4vxjCN9LPx6y8MHO8T523Im0cS5vx1VTV8jmjVnX9biLTX6?= =?us-ascii?Q?XYe/NL9YwwabYHtXJkXStAXy4dP+M0Hn3mVMDx1shlSCa1/tXK7tRVyKW4wL?= =?us-ascii?Q?bTMQBLeejjRniKbzy2bE6hY+jW1csBiptdnPU8IWp5SMyVUr5ltIAicLbOAh?= =?us-ascii?Q?lHWFhHLA1i7TW/fDsLe2AlXoNoNngo/FrPscYM3aBP+UJntnWg6Xmg//LoWD?= =?us-ascii?Q?PUYjnfrDgRAkz9LXm93M6aXieZGBn9Phu2MkcgEzWTAIN3dtShzohFw6lo2g?= =?us-ascii?Q?J9y2nlm/GgPbS9Zf64sPqTFmB8+/V+sOkQVNExDdcdbFL3/F4W1B3u4vKJRm?= =?us-ascii?Q?QTjXw+g/DKfjO5hE3/tWYsYXBR+2utMsavnwCAiNGgkUpFJzCRCnc/CbhfTq?= =?us-ascii?Q?9Pm04Er+m1YW5Ljw5But1Fdh7Hu4bM4QXpeFobdZbBAdDjVJ6FyLLQGAEPZF?= =?us-ascii?Q?adV+PE0Isc+/FdFa8f9PC4DWNE0xJeBgEK5BJeuwt/EmiV/OG8eZI9h4QcDl?= =?us-ascii?Q?SajKcL1rch6D2q2+51o8C9L2YTKFRpwaCGF2UG3hlUZL7GyJqAucCS4aw4F7?= =?us-ascii?Q?pyjH0iqXxBsYXBfTlBglr5oz0+lJ5s4FWKlF94Pr+ruU8CBUocScsTSfjKz5?= =?us-ascii?Q?+kS/oo0EO/qNHBvrMq4QUm0rxfTYqfiWSh0WXFV0S9/XPFBJx5HbNrIVghy+?= =?us-ascii?Q?avdXZmhMWOSgkNxFaTw0hMH3QN7pvwcmGpkJqS4ZzCw8NClGq9umySPv46o4?= =?us-ascii?Q?OmOL90pE78FOTjqMH5eZNN+SNIrlNXSum6eB9+eY+Ew0ltMPyWjXriZdN7Wp?= =?us-ascii?Q?PRC08YoII3BeWBraUNGndS9wjtSLOFVG8OsXtGhQ/sk9L6x1buGVS/e04bQq?= =?us-ascii?Q?CpBBNdgoa2w45eb2g1LKv6UmV3shgAf6MMyt7So32kb/kL0K81cLJPcm/NgZ?= =?us-ascii?Q?7pbtb7cFSsG4Ic+00tczJA+oOuKFdDWumaElxkRmHyE3On1nvwLCYzwDKO7D?= =?us-ascii?Q?j5qmWVir8hLf+9MGSeIcLzHfQkK7ut1Q4/q326LFXgrN6ToBUdTys59FtDxA?= =?us-ascii?Q?Qg8p+hka+Uuq1nTAPlpcasHjB2GuZevUAx5yUyqRhTuXwE8PL27v2pzAVopJ?= =?us-ascii?Q?2MPOSKJ57BxOh6cAKhweQDRF0FNEmdDyoCbZ9cTO2s5O5M9zolUdRvsuyAop?= =?us-ascii?Q?bKqo/nMOKJpNXDLDvXx8QN9GJhUzuUA2EvbR?= 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)(36860700013)(1800799024)(7416014)(376014);DIR:OUT;SFP:1101; X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 30 Jul 2025 21:56:50.1766 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: 15def575-a883-4091-9e01-08ddcfb3fcb3 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: BL6PEPF0001AB78.namprd02.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: SA1PR12MB7444 Content-Type: text/plain; charset="utf-8" From: Ashish Kalra After a panic if SNP is enabled in the previous kernel then the kdump kernel boots with IOMMU SNP enforcement still enabled. IOMMU command buffers and event buffer registers remain locked and exclusive to the previous kernel. Attempts to enable command and event buffers in the kdump kernel will fail, as hardware ignores writes to the locked MMIO registers as per AMD IOMMU spec Section 2.12.2.1. Skip enabling command buffers and event buffers for kdump boot as they are already enabled in the previous kernel. Tested-by: Sairaj Kodilkar Signed-off-by: Ashish Kalra Reviewed-by: Vasant Hegde --- drivers/iommu/amd/init.c | 28 +++++++++++++++++++--------- 1 file changed, 19 insertions(+), 9 deletions(-) diff --git a/drivers/iommu/amd/init.c b/drivers/iommu/amd/init.c index 05d9c1764883..4e792a112b48 100644 --- a/drivers/iommu/amd/init.c +++ b/drivers/iommu/amd/init.c @@ -821,11 +821,16 @@ static void iommu_enable_command_buffer(struct amd_io= mmu *iommu) =20 BUG_ON(iommu->cmd_buf =3D=3D NULL); =20 - entry =3D iommu_virt_to_phys(iommu->cmd_buf); - entry |=3D MMIO_CMD_SIZE_512; - - memcpy_toio(iommu->mmio_base + MMIO_CMD_BUF_OFFSET, - &entry, sizeof(entry)); + if (!is_kdump_kernel()) { + /* + * Command buffer is re-used for kdump kernel and setting + * of MMIO register is not required. + */ + entry =3D iommu_virt_to_phys(iommu->cmd_buf); + entry |=3D MMIO_CMD_SIZE_512; + memcpy_toio(iommu->mmio_base + MMIO_CMD_BUF_OFFSET, + &entry, sizeof(entry)); + } =20 amd_iommu_reset_cmd_buffer(iommu); } @@ -876,10 +881,15 @@ static void iommu_enable_event_buffer(struct amd_iomm= u *iommu) =20 BUG_ON(iommu->evt_buf =3D=3D NULL); =20 - entry =3D iommu_virt_to_phys(iommu->evt_buf) | EVT_LEN_MASK; - - memcpy_toio(iommu->mmio_base + MMIO_EVT_BUF_OFFSET, - &entry, sizeof(entry)); + if (!is_kdump_kernel()) { + /* + * Event buffer is re-used for kdump kernel and setting + * of MMIO register is not required. + */ + entry =3D iommu_virt_to_phys(iommu->evt_buf) | EVT_LEN_MASK; + memcpy_toio(iommu->mmio_base + MMIO_EVT_BUF_OFFSET, + &entry, sizeof(entry)); + } =20 /* set head and tail to zero manually */ writel(0x00, iommu->mmio_base + MMIO_EVT_HEAD_OFFSET); --=20 2.34.1