From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from NAM10-MW2-obe.outbound.protection.outlook.com (mail-mw2nam10on2071.outbound.protection.outlook.com [40.107.94.71]) (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 12EED2C187; Tue, 7 Jan 2025 19:46:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=40.107.94.71 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736279221; cv=fail; b=i4wlEf/Bk5BckRlJM6IUPIStO5UMM2SuD/pS+6ylSJA2x9puL7EezhfMf5GrphNO2vnRj2iKnEYXyqr8nGc63ZeyvYq3oIeOMWnHgSNeTjyH6UVwYLoTSCYgMj0W3kj713IJSf6n+lenWXzteEtwF4efxzGzheGi//dlfZMd09I= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736279221; c=relaxed/simple; bh=ypK9Yn0hRVXVDS5r8GTrA2LpeoTCEud40X95HBHgXHw=; h=Message-ID:Date:To:Cc:References:From:Subject:In-Reply-To: Content-Type:MIME-Version; b=aRguohSXrIAVtfK7D2QvUxEThJ0vntwO9yZGIg01BKSdnOpfjrS6M8yLkngi6kccLPINff2se8mRtpI/M2Z2NwN+yr1cg+8TEc8iTkzBkiIkE20MAHjwQMratEflqFwTbx7tIepqJbo31n5r62brEn4Dq4Wqn14UG8+IQTu3S7E= 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=5SsdiVqY; arc=fail smtp.client-ip=40.107.94.71 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="5SsdiVqY" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=cZMto6YIaRxC8+vckdAxHMunzAmrMPJgBl06o0g1dHiL3poyxQpFgnGEJcyYBGkD0X3sOhR7k4xlwFnjLKTkwsqq1UBHIcGveUb2EdbAzcVp/Ltc87rFQ9r+KTbFyz1gJu8kBgud5YzFcyI5syi+z7N3FSAtysx9r37/TKg3d+xbW36DsoTvvmFRRcubSRaEd3iP8Kfo0A1+xjDVdJkIPoCLrd/QtZwyNmRsr0G1/WbVS06WDr8A5fNMqkPsoxy53kcPRoxrWlBlAPVlYQF8R/dQU+wEH2LmWJxbywN/4Q8DqHYPBxHtFpLEhkP/gDg1hOFe3kBdB2hnjharC8NOwg== 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=BYbFLZj3aMW5HCFHnIfvkiAZfCElM/cBb1gizTx2sfQ=; b=Hc2JjGuw43B4hqJC0057uhTNpnBW7SCz1InFf6t6GsWm1EcVHMtDDT0CbQw25MpoY6nTqG6B0ToMXi70Y+24tZcoviYXc60w8XjLxTzxk7UO/GhYa/lEPUycEI+RV51kkmJA/sUPkuywFJb6MUqvwXZKVa18qRigNv+u9hbwqjyL+bnNI0jJ/mulTeXHjVyTDf7RD/M4vpPz/5oM7Nkg20koxM2q8S+N5flfp5ygZpn7YuNxwKa4puviOlT05B/FWEz4tXiHagVzQK36S5ZbgO4keq8+Z5dsbY14L4qAq1WnvnNf39++CzX8JW1zadgZEWnHzyySBJhO0mxf7VlCQw== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=amd.com; dmarc=pass action=none header.from=amd.com; dkim=pass header.d=amd.com; arc=none 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=BYbFLZj3aMW5HCFHnIfvkiAZfCElM/cBb1gizTx2sfQ=; b=5SsdiVqY+kK6gko7nLcR9B43n31oNcEmaZhweHlCDL0pihvAyVg+JHUR43FnUsfBneWanQBgAPMfUKYUDbpxD9bZI40dI8nz3yShMLldGEKn+td/xA/v5TDOUcEE8SGSpIeAJpxrlz24SWzwZ6fgR0kmW2Rd+6yjyHVWDJFtoFo= Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=amd.com; Received: from DM4PR12MB5070.namprd12.prod.outlook.com (2603:10b6:5:389::22) by SN7PR12MB6840.namprd12.prod.outlook.com (2603:10b6:806:264::14) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.8314.17; Tue, 7 Jan 2025 19:46:51 +0000 Received: from DM4PR12MB5070.namprd12.prod.outlook.com ([fe80::20a9:919e:fd6b:5a6e]) by DM4PR12MB5070.namprd12.prod.outlook.com ([fe80::20a9:919e:fd6b:5a6e%7]) with mapi id 15.20.8335.010; Tue, 7 Jan 2025 19:46:51 +0000 Message-ID: Date: Tue, 7 Jan 2025 13:46:49 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.15.1 Content-Language: en-US To: Nikunj A Dadhania , linux-kernel@vger.kernel.org, bp@alien8.de, x86@kernel.org Cc: kvm@vger.kernel.org, mingo@redhat.com, tglx@linutronix.de, dave.hansen@linux.intel.com, pgonda@google.com, seanjc@google.com, pbonzini@redhat.com, francescolavra.fl@gmail.com References: <20250106124633.1418972-1-nikunj@amd.com> <20250106124633.1418972-6-nikunj@amd.com> From: Tom Lendacky Subject: Re: [PATCH v16 05/13] x86/sev: Add Secure TSC support for SNP guests In-Reply-To: <20250106124633.1418972-6-nikunj@amd.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-ClientProxiedBy: SN7PR18CA0012.namprd18.prod.outlook.com (2603:10b6:806:f3::35) To DM4PR12MB5070.namprd12.prod.outlook.com (2603:10b6:5:389::22) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: DM4PR12MB5070:EE_|SN7PR12MB6840:EE_ X-MS-Office365-Filtering-Correlation-Id: 21019a70-810f-4286-24cd-08dd2f540805 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|366016|376014|7416014|1800799024; X-Microsoft-Antispam-Message-Info: =?utf-8?B?cXloYlNvRzlmRnptMFdWTHJVMWZ2RUovMFRzWEhIZDR0eG5RTWFIcWVaT2hs?= =?utf-8?B?dEhDM0dKT1JLSDlFYWk5TElYaVArK2QyMEd4OVVabDZ4eG5ibnhNNmtsZE1P?= =?utf-8?B?Vnk0NU1KVGpXcStSbG5vdkNuQTQxNnh0MUxXSUpFMWVVdUVSMWloUHdmZ1Iz?= =?utf-8?B?VGJXemdsVlVSUkZEQTRlNGh2RHFTNUo2VUdyZldsMjBMK0hWQ29wdFFIaWJH?= =?utf-8?B?WW9lNFIrRHZhSFZGb3VkVDFUZ0Q3UGZ3UzVzcTExT0ZyWHdxbWhEQWY2NGVX?= =?utf-8?B?djI4LzV5SThveFhkVkpiZVl5K0xLM0NFbWRQOWJxU0pzdHozMVVwTG5YanAz?= =?utf-8?B?clVZWDVmbWRETXlCYXJ5RHNKNDRtbFFETnRBOWhWMnBvcFF1SzVCbnVMZTVV?= =?utf-8?B?cFJ1WXF4L0VPVHlpT3Q1bTdWMnE1K0NmTXEwSU9ZQThxOURIZnRzakxndkgz?= =?utf-8?B?Wm45UkZLZDBsTGM3L2JIN2IyZnduOTVoK2hMS09lNjMxUmVicFM5QUJqSFl6?= =?utf-8?B?V3cvZTY4M1B2ZW1YTGZTQlRKUFhseURUSFNnV2N2WVhVR0d6TjcreWZSaU8v?= =?utf-8?B?aitVbjEyYUFCOHdKMVJPaUNXR0FxODU4QWV0WE9oOGJ4cWFMTDE3ZnZqWFR0?= =?utf-8?B?SUlmQzNXZEQ4QXRWSXhKMlV3TUxNNm0zb1dtZFdRakhwbVR0bEV0KyswdEQy?= =?utf-8?B?WjdLR2RGT0FDc1ZhV2dreU53TGNhdCtTVzhtUUJKaXFMMmtSRVRNMVR4cEdh?= =?utf-8?B?Qjl2MUwxbHk0aUY1NlJQRDVlTnBYZFdxTlVyejhQdjM0MDJ0dGhYazF4Qkxj?= =?utf-8?B?TnZpMy9RQXFPbGRxYkNIR1o1L21uOWorY3dFdi9kbjhJU0oxd2YvQTMram93?= =?utf-8?B?aGhsZXM5UkpCVy8wVGJBQ09UTlFZaER6Y2cvN2tiZitObUdSODg3cnVWZmZy?= =?utf-8?B?UFo3NWFQYVA5bXRIZklsSTFBem42VmI0MkNRZ1lvdmg1dytUeXRUYUZ3YzNq?= =?utf-8?B?SWhHNUw1cit1REVxQ3ZUOUwyVndDNjJTR3hOT1k1YTRvd2V5dGNheWcrRXk0?= =?utf-8?B?S2plOVJ3RDk1ZVlLa1VEOGdCM3ZVYTZBSnV6djQxU2djYVJoRkNObkhPa0tG?= =?utf-8?B?L1hqajFKeHZDYkdwaW8rS01PMWxYRzZ1eHl2dXNLL25weGxtcXpNMk5mSjNz?= =?utf-8?B?WWhQbmYybDlrZ2RBMVpYamk0SUhORHRmVTdqNDc2TkpkV2w4aERXQnZJbVZx?= =?utf-8?B?Q1Z1eHVBQktXRWpaRHUreWFXUDBRcktmdys3YVRXUnNoUTNtUENWaFlLZVNa?= =?utf-8?B?Q25ZSjZUYzhZRzg1OFdPZjYrQTYzcWpiRE9DQy95VGNNSlo3b0VUUngvNmo4?= =?utf-8?B?dElVU0JvSHIvWmZVeVJEOFhFNkM1V0l5UHJpbFJpU0FJRldKYkxkcmVLbnlk?= =?utf-8?B?bndBdmxtWHJrL1ZCaGxPVEgvbXVwUVVGRFhnTmJaeWNJRHVtcklvSHV2K3dS?= =?utf-8?B?RnF2Y1FzeW9md1BXdGEzRHBrV0VPdEp0KzY5RlNmMjBkSGszeU1QZXpBMWJk?= =?utf-8?B?MEx4MmdzZVFyNnViNWRoZEFIK250OTNBdzBObWRLZlBzTEJGZWd6T2RLbHhC?= =?utf-8?B?V0hUK1FmNXRsT0hJYTFyQjJ1Y2krc1dJZmplK3VCMmJQdndvYm00RjA0RkEr?= =?utf-8?B?SHJlTGsrNnQ2ZW9kTXNKTGg3S212SEdpazJ2MHJlS0Z6d1RNOWZLQkxKTytp?= =?utf-8?B?SlJrN0xwdmczdmVaMlNQdlQ2ZUF5MzZoZzUyczhwaHl3MFY4M0dHcmY3R29t?= =?utf-8?B?cDduMmNWS01lWDdsalcyUk5Ndm9EMm1rV2pMcXJia25GYkk5dVRpQ2Y1Q1Fr?= =?utf-8?Q?S+Bc0gp7oU1F+?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:DM4PR12MB5070.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(366016)(376014)(7416014)(1800799024);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?MzI5Ukg2cjIyTE5LbkI5am9sc2hKN0ZGaEV6TFg1QkpUSnpKVkRCUGk3eXFi?= =?utf-8?B?bEsvVVhRUlIyWjdFb21ES2hnUjVmWXFtbkNleTFQVEVlUE1BZkFRY09Fb2c2?= =?utf-8?B?akhTdkYzRmtFd1ZLVXAvbU1HR2MrWjRMVVRCdnZjUHFxeUx2cUZIVVFDTUtv?= =?utf-8?B?K2NLa2pJcU9EVUFhVnhoZ2ExSSs4dnFnV0hNY3BxQ1FXNW0wbmJuRWFzdTQx?= =?utf-8?B?MlRWSlJEVCtEWnNiMHdxd0w4djlWK3NQYm9Yeit0eFFncWZlZXg1WFd4ZDhP?= =?utf-8?B?VnpIWGdaZk9SbG9pOHdGY21kYldHWXl0dkpTTWwxTFhTSTRWNlF5aWRJeGw1?= =?utf-8?B?aWJLWDVQN201MzRQTkMwaGZTRzIwUGVDTmNrS3VFMUZ1bUsvMEJlTDNBemQ0?= =?utf-8?B?TU02QTV0MGdCQkdiOUFieS9NVmFBaThvU2h2Z1BqZjIxVk5OblhJdHdYTzli?= =?utf-8?B?M2xhTW5JS1lJUklGVEQ1YkIvOEZVOUloTXZMTFJkZWZHTnlsaHo5WHYzamta?= =?utf-8?B?NXFCTktuYmFHZW1aWWp0WVcyWVFhTyt0Z1FRLzU3VUVMdWI2UGtZTU1CZm9x?= =?utf-8?B?U1FxNnhkcUU2aW5XamdSMlliKysyVHFWK3J0ZzJFM3lEOTJHUm94RzFUOVhK?= =?utf-8?B?TkkxUndzWXNBQzdYd3pIUk5DL2dHRDhUc0RocngvZkVUZW16VWs3M0UwUWZk?= =?utf-8?B?ZjJEZUhGQklCZ0ZXZjYwWlpiUHdlYWNjdW4vTUptNG9ZUlYxazMwWnhnTXZS?= =?utf-8?B?ZjJGcVFTNTJ0S2NzTTNLU1EvWHA1U1A2VllWSFBwT2tHa253YmZjYUI1Rk9I?= =?utf-8?B?aEFreWZuWmR0UldrdHFIN01lNTFWb281cW44ZXlPVW9OQjNDUWRVaGMyM2ky?= =?utf-8?B?R3RiR1hnZUl4d3FOZTNqU2h0MVZPa3laMUpqV25Rb0E2Q1U3dy91YitDLzF0?= =?utf-8?B?TE1Pdm5HZVpOVFhJM1BjWThYaVVPdU9pUm1jSjdMU1lFY0lnNnU2YVJKbFhu?= =?utf-8?B?YkZmQjU5NDRyTnJDU1RVMUxHQkZKTzNIOHppa2NBNW5XQ250UE5vUTl2UXdx?= =?utf-8?B?UFBnWFBoajJDTDE1ZXF6bkxwbDJuVFU3OTdST0VaZ044c2taWjArMkJZQ1dY?= =?utf-8?B?UGlOdWxUaDV5VVNGN1c2YUE5aER4aWU2WGcwQ0RQQjdaMldnL3UvL3YrdHhN?= =?utf-8?B?ZWFLUkYxdUorWGJlWm0zVzR5RjNYQkVCYWdYakdPNFZjZS9oN2wwbWUvRnV4?= =?utf-8?B?U25MMkNRUXZmSVA4VlhpcnZESVhYUXY3QXM4N0R3aWpURE9FTWY4UW5FQ0JC?= =?utf-8?B?WFNKci9qc3BKWEZvQlNjc2hzWFFqRUpjdDhyNUtqUTdtaGJydnNrR0MwWkU4?= =?utf-8?B?M2t4N0hacmIvSG9ERjljUjVjWkJNQjhTZ0Z3M0hQamZNektnb0RQZkZadUUr?= =?utf-8?B?V2FZRkl6ZDU0TVlDOUdVMVJCM1VYZEJ6WGlWRGFpMjhJaWNXTFBxYTE0cHZX?= =?utf-8?B?ZjdsQUZwRDZ3eURUeEQ1bGE2VnB3b3VMYkZ0eW5rcXNoV29CVU9SbWhjbnYv?= =?utf-8?B?SDN3WXRBNG9PeTQzQ3FEbU5ISVRTM2FIVU9DRFNJUDF2cENxSjNIcm1RTEFj?= =?utf-8?B?NXpCMkJtZDhRaDZocWc2Rk5sQkxnY0tHa1NDQk9RVDZPSHJ5UmFPN01zMnBE?= =?utf-8?B?blRRRytCMUZCbkhPTW9OamVLUjBWWkNobTRQa1kxNmVqbFhNeG5jNHpFemtE?= =?utf-8?B?UHlqbkwwTHpqVERzejliQlA5UjBEeEZXUkRqa0ZBSDdqMGNvZUVrV1Nqd0Fn?= =?utf-8?B?aTE2Wmd1VGNVTGlEbHh1My9CUVZOTjFQT2J2UVRhUHhkc2hSM0JBSmpzUmdK?= =?utf-8?B?ZFpvS0t1TXJHQlA4Qld3Z2wrc2pOZEcwekFuL2xMcWd0ekhBWmdEMWtkNTJD?= =?utf-8?B?MlZJUlZkMWFIMVFyOVpzemNZVk1RUTZqZmdJdlVlVlY3TzNIbCtKZ2pkVzE5?= =?utf-8?B?NVBCaG1MTzlpbjgwbGlZS08xT1NqM2t2VVpXblZxbEwzRUJqUmxtMUtlalRr?= =?utf-8?B?bnFTamZoMW9qd2JrM0tWYUNPVXNueVdRL3ZFckZZLzlONFkrZ1hQQ1ZJcEsy?= =?utf-8?Q?mnliylTCVJamoTqMp9ZzOYVzA?= X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-Network-Message-Id: 21019a70-810f-4286-24cd-08dd2f540805 X-MS-Exchange-CrossTenant-AuthSource: DM4PR12MB5070.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 07 Jan 2025 19:46:51.6467 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: 2csoCM16qCaQ7hr8qMrrHgEbLW+NfpDx34cHj8nPNq8RsxYwkH3sBVNgjziItwjIZfn5WmtclG3irwTPiPyYEg== X-MS-Exchange-Transport-CrossTenantHeadersStamped: SN7PR12MB6840 On 1/6/25 06:46, Nikunj A Dadhania wrote: > Add support for Secure TSC in SNP-enabled guests. Secure TSC allows guests > to securely use RDTSC/RDTSCP instructions, ensuring that the parameters > used cannot be altered by the hypervisor once the guest is launched. > > Secure TSC-enabled guests need to query TSC information from the AMD > Security Processor. This communication channel is encrypted between the AMD > Security Processor and the guest, with the hypervisor acting merely as a > conduit to deliver the guest messages to the AMD Security Processor. Each > message is protected with AEAD (AES-256 GCM). > > Signed-off-by: Nikunj A Dadhania Reviewed-by: Tom Lendacky Although if you have to re-spin, it might make sense to use the __free() support to reduce the number of gotos and labels in snp_get_tsc_info(). You could also use kfree_sensitive() to automatically do the memzero_explicit(), too. > --- > arch/x86/include/asm/sev-common.h | 1 + > arch/x86/include/asm/sev.h | 21 ++++++ > arch/x86/include/asm/svm.h | 6 +- > include/linux/cc_platform.h | 8 +++ > arch/x86/coco/core.c | 4 ++ > arch/x86/coco/sev/core.c | 107 ++++++++++++++++++++++++++++++ > arch/x86/mm/mem_encrypt.c | 2 + > 7 files changed, 147 insertions(+), 2 deletions(-) > > diff --git a/arch/x86/include/asm/sev-common.h b/arch/x86/include/asm/sev-common.h > index 50f5666938c0..6ef92432a5ce 100644 > --- a/arch/x86/include/asm/sev-common.h > +++ b/arch/x86/include/asm/sev-common.h > @@ -206,6 +206,7 @@ struct snp_psc_desc { > #define GHCB_TERM_NO_SVSM 7 /* SVSM is not advertised in the secrets page */ > #define GHCB_TERM_SVSM_VMPL0 8 /* SVSM is present but has set VMPL to 0 */ > #define GHCB_TERM_SVSM_CAA 9 /* SVSM is present but CAA is not page aligned */ > +#define GHCB_TERM_SECURE_TSC 10 /* Secure TSC initialization failed */ > > #define GHCB_RESP_CODE(v) ((v) & GHCB_MSR_INFO_MASK) > > diff --git a/arch/x86/include/asm/sev.h b/arch/x86/include/asm/sev.h > index 0937ac7a96db..bdcdaac4df1c 100644 > --- a/arch/x86/include/asm/sev.h > +++ b/arch/x86/include/asm/sev.h > @@ -146,6 +146,9 @@ enum msg_type { > SNP_MSG_VMRK_REQ, > SNP_MSG_VMRK_RSP, > > + SNP_MSG_TSC_INFO_REQ = 17, > + SNP_MSG_TSC_INFO_RSP, > + > SNP_MSG_TYPE_MAX > }; > > @@ -174,6 +177,21 @@ struct snp_guest_msg { > u8 payload[PAGE_SIZE - sizeof(struct snp_guest_msg_hdr)]; > } __packed; > > +#define SNP_TSC_INFO_REQ_SZ 128 > + > +struct snp_tsc_info_req { > + u8 rsvd[SNP_TSC_INFO_REQ_SZ]; > +} __packed; > + > +struct snp_tsc_info_resp { > + u32 status; > + u32 rsvd1; > + u64 tsc_scale; > + u64 tsc_offset; > + u32 tsc_factor; > + u8 rsvd2[100]; > +} __packed; > + > struct snp_guest_req { > void *req_buf; > size_t req_sz; > @@ -463,6 +481,8 @@ void snp_msg_free(struct snp_msg_desc *mdesc); > int snp_send_guest_request(struct snp_msg_desc *mdesc, struct snp_guest_req *req, > struct snp_guest_request_ioctl *rio); > > +void __init snp_secure_tsc_prepare(void); > + > #else /* !CONFIG_AMD_MEM_ENCRYPT */ > > #define snp_vmpl 0 > @@ -503,6 +523,7 @@ static inline struct snp_msg_desc *snp_msg_alloc(void) { return NULL; } > static inline void snp_msg_free(struct snp_msg_desc *mdesc) { } > static inline int snp_send_guest_request(struct snp_msg_desc *mdesc, struct snp_guest_req *req, > struct snp_guest_request_ioctl *rio) { return -ENODEV; } > +static inline void __init snp_secure_tsc_prepare(void) { } > > #endif /* CONFIG_AMD_MEM_ENCRYPT */ > > diff --git a/arch/x86/include/asm/svm.h b/arch/x86/include/asm/svm.h > index 2b59b9951c90..92e18798f197 100644 > --- a/arch/x86/include/asm/svm.h > +++ b/arch/x86/include/asm/svm.h > @@ -417,7 +417,9 @@ struct sev_es_save_area { > u8 reserved_0x298[80]; > u32 pkru; > u32 tsc_aux; > - u8 reserved_0x2f0[24]; > + u64 tsc_scale; > + u64 tsc_offset; > + u8 reserved_0x300[8]; > u64 rcx; > u64 rdx; > u64 rbx; > @@ -564,7 +566,7 @@ static inline void __unused_size_checks(void) > BUILD_BUG_RESERVED_OFFSET(sev_es_save_area, 0x1c0); > BUILD_BUG_RESERVED_OFFSET(sev_es_save_area, 0x248); > BUILD_BUG_RESERVED_OFFSET(sev_es_save_area, 0x298); > - BUILD_BUG_RESERVED_OFFSET(sev_es_save_area, 0x2f0); > + BUILD_BUG_RESERVED_OFFSET(sev_es_save_area, 0x300); > BUILD_BUG_RESERVED_OFFSET(sev_es_save_area, 0x320); > BUILD_BUG_RESERVED_OFFSET(sev_es_save_area, 0x380); > BUILD_BUG_RESERVED_OFFSET(sev_es_save_area, 0x3f0); > diff --git a/include/linux/cc_platform.h b/include/linux/cc_platform.h > index caa4b4430634..0bf7d33a1048 100644 > --- a/include/linux/cc_platform.h > +++ b/include/linux/cc_platform.h > @@ -81,6 +81,14 @@ enum cc_attr { > */ > CC_ATTR_GUEST_SEV_SNP, > > + /** > + * @CC_ATTR_GUEST_SNP_SECURE_TSC: SNP Secure TSC is active. > + * > + * The platform/OS is running as a guest/virtual machine and actively > + * using AMD SEV-SNP Secure TSC feature. > + */ > + CC_ATTR_GUEST_SNP_SECURE_TSC, > + > /** > * @CC_ATTR_HOST_SEV_SNP: AMD SNP enabled on the host. > * > diff --git a/arch/x86/coco/core.c b/arch/x86/coco/core.c > index 0f81f70aca82..715c2c09582f 100644 > --- a/arch/x86/coco/core.c > +++ b/arch/x86/coco/core.c > @@ -97,6 +97,10 @@ static bool noinstr amd_cc_platform_has(enum cc_attr attr) > case CC_ATTR_GUEST_SEV_SNP: > return sev_status & MSR_AMD64_SEV_SNP_ENABLED; > > + case CC_ATTR_GUEST_SNP_SECURE_TSC: > + return (sev_status & MSR_AMD64_SEV_SNP_ENABLED) && > + (sev_status & MSR_AMD64_SNP_SECURE_TSC); > + > case CC_ATTR_HOST_SEV_SNP: > return cc_flags.host_sev_snp; > > diff --git a/arch/x86/coco/sev/core.c b/arch/x86/coco/sev/core.c > index feb145df6bf7..00a0ac3baab7 100644 > --- a/arch/x86/coco/sev/core.c > +++ b/arch/x86/coco/sev/core.c > @@ -96,6 +96,14 @@ static u64 sev_hv_features __ro_after_init; > /* Secrets page physical address from the CC blob */ > static u64 secrets_pa __ro_after_init; > > +/* > + * For Secure TSC guests, the BSP fetches TSC_INFO using SNP guest messaging and > + * initializes snp_tsc_scale and snp_tsc_offset. These values are replicated > + * across the APs VMSA fields (TSC_SCALE and TSC_OFFSET). > + */ > +static u64 snp_tsc_scale __ro_after_init; > +static u64 snp_tsc_offset __ro_after_init; > + > /* #VC handler runtime per-CPU data */ > struct sev_es_runtime_data { > struct ghcb ghcb_page; > @@ -1272,6 +1280,12 @@ static int wakeup_cpu_via_vmgexit(u32 apic_id, unsigned long start_ip) > vmsa->vmpl = snp_vmpl; > vmsa->sev_features = sev_status >> 2; > > + /* Populate AP's TSC scale/offset to get accurate TSC values. */ > + if (cc_platform_has(CC_ATTR_GUEST_SNP_SECURE_TSC)) { > + vmsa->tsc_scale = snp_tsc_scale; > + vmsa->tsc_offset = snp_tsc_offset; > + } > + > /* Switch the page over to a VMSA page now that it is initialized */ > ret = snp_set_vmsa(vmsa, caa, apic_id, true); > if (ret) { > @@ -3121,3 +3135,96 @@ int snp_send_guest_request(struct snp_msg_desc *mdesc, struct snp_guest_req *req > return 0; > } > EXPORT_SYMBOL_GPL(snp_send_guest_request); > + > +static int __init snp_get_tsc_info(void) > +{ > + struct snp_guest_request_ioctl *rio; > + struct snp_tsc_info_resp *tsc_resp; > + struct snp_tsc_info_req *tsc_req; > + struct snp_msg_desc *mdesc; > + struct snp_guest_req *req; > + int rc = -ENOMEM; > + > + tsc_req = kzalloc(sizeof(*tsc_req), GFP_KERNEL); > + if (!tsc_req) > + return rc; > + > + /* > + * The intermediate response buffer is used while decrypting the > + * response payload. Make sure that it has enough space to cover > + * the authtag. > + */ > + tsc_resp = kzalloc(sizeof(*tsc_resp) + AUTHTAG_LEN, GFP_KERNEL); > + if (!tsc_resp) > + goto e_free_tsc_req; > + > + req = kzalloc(sizeof(*req), GFP_KERNEL); > + if (!req) > + goto e_free_tsc_resp; > + > + rio = kzalloc(sizeof(*rio), GFP_KERNEL); > + if (!rio) > + goto e_free_req; > + > + mdesc = snp_msg_alloc(); > + if (IS_ERR_OR_NULL(mdesc)) > + goto e_free_rio; > + > + rc = snp_msg_init(mdesc, snp_vmpl); > + if (rc) > + goto e_free_mdesc; > + > + req->msg_version = MSG_HDR_VER; > + req->msg_type = SNP_MSG_TSC_INFO_REQ; > + req->vmpck_id = snp_vmpl; > + req->req_buf = tsc_req; > + req->req_sz = sizeof(*tsc_req); > + req->resp_buf = (void *)tsc_resp; > + req->resp_sz = sizeof(*tsc_resp) + AUTHTAG_LEN; > + req->exit_code = SVM_VMGEXIT_GUEST_REQUEST; > + > + rc = snp_send_guest_request(mdesc, req, rio); > + if (rc) > + goto e_request; > + > + pr_debug("%s: response status 0x%x scale 0x%llx offset 0x%llx factor 0x%x\n", > + __func__, tsc_resp->status, tsc_resp->tsc_scale, tsc_resp->tsc_offset, > + tsc_resp->tsc_factor); > + > + if (!tsc_resp->status) { > + snp_tsc_scale = tsc_resp->tsc_scale; > + snp_tsc_offset = tsc_resp->tsc_offset; > + } else { > + pr_err("Failed to get TSC info, response status 0x%x\n", tsc_resp->status); > + rc = -EIO; > + } > + > +e_request: > + /* The response buffer contains sensitive data, explicitly clear it. */ > + memzero_explicit(tsc_resp, sizeof(*tsc_resp) + AUTHTAG_LEN); > +e_free_mdesc: > + snp_msg_free(mdesc); > +e_free_rio: > + kfree(rio); > +e_free_req: > + kfree(req); > + e_free_tsc_resp: > + kfree(tsc_resp); > +e_free_tsc_req: > + kfree(tsc_req); > + > + return rc; > +} > + > +void __init snp_secure_tsc_prepare(void) > +{ > + if (!cc_platform_has(CC_ATTR_GUEST_SNP_SECURE_TSC)) > + return; > + > + if (snp_get_tsc_info()) { > + pr_alert("Unable to retrieve Secure TSC info from ASP\n"); > + sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_SECURE_TSC); > + } > + > + pr_debug("SecureTSC enabled"); > +} > diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c > index 0a120d85d7bb..95bae74fdab2 100644 > --- a/arch/x86/mm/mem_encrypt.c > +++ b/arch/x86/mm/mem_encrypt.c > @@ -94,6 +94,8 @@ void __init mem_encrypt_init(void) > /* Call into SWIOTLB to update the SWIOTLB DMA buffers */ > swiotlb_update_mem_attributes(); > > + snp_secure_tsc_prepare(); > + > print_mem_encrypt_feature_info(); > } >