From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from NAM12-DM6-obe.outbound.protection.outlook.com (mail-dm6nam12on2049.outbound.protection.outlook.com [40.107.243.49]) (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 1EFE3481B3; Thu, 24 Oct 2024 04:01:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=40.107.243.49 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729742479; cv=fail; b=CA1uRZqSdj7wlD0117BnQjNlSWMAJztRpR6xIBfedZuI7Mdu2GqR8fas0tzUWE8vqKU5b9X+EmWe9LRNRGgRTLftMAdm0cLXa94GsWf9lV3lIoFB3UoCJ/bkBDq5pZBKO0fGDvIax5XGROzDJzMefo2hPYZTSzKcyzO83ZQdCuU= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729742479; c=relaxed/simple; bh=3k+yEtnABsq7WJYSNGDkafjfaAr37uoz1FRyx7SKEHI=; h=Message-ID:Date:Subject:To:Cc:References:From:In-Reply-To: Content-Type:MIME-Version; b=g1rkLwxqTn8Fx+SDTFguDcjY3jPG1WBnzdIHfME28O9am1o8/f538a1S1oYl5zGiarzw1yZUXYdCAiC56k3YVVlLxRbiy0gmklKCj/eczsspiKFEEbx4q8mhaifI2JsdLrBeSW3Q/3wWkAr68CTChM5K8pxKSli7ebD9Ny9w+gc= 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=Hw3dLPgk; arc=fail smtp.client-ip=40.107.243.49 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="Hw3dLPgk" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=ZU/lFHAjS/BPIZVqO/sQT5708U8mGB2rKV6oXtUp7CDLdZYnTXmLRoB4wvVIvvvBjqb5uNN1paajKCJ/S7RFOAOE9WEUePzevMledXnATlX1I27rQ6q5aRqI4F3VuQ+/nBGSOWUItMOFbLXmWYPdHYXuHtnKCzRNSo3TTfYTdTl0n5BKN/PnRM9KALzTax5Ls35U7wS5mA6ErhegegwCNayP1wpUFj8EMfiSQTnxm1wJqPhVavQsd8fV/b0xfkxWlUNVWOqWb2eJw6P9Vs47rnlzMa4hfbQN5AqYMJcCt8ea8OGOmAeevyQojPryCtOSqL+4SvoXQC7exq+1+WICDQ== 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=zj629QuraNxxO6GbeRTz0l7pFelQiOG3qWST6r/v/Ug=; b=GtnZFJrGjCG/PciO00tVOJEtXnJgyZgplUnkbVWz2LFkJdY17Jr4ASGsV/upuPAKw/hhYGQGQ4BPtoiYiS9w8khBAmbsPcsP6zQiElz9zKagGg8TCCNesaRZjiqFqEawIl2uBebXp5XlgLoj174NVI4bgQ0O8AAGp6Nf8w1ml58Hj9fjle2RCMf286L6KhrozKVcNFYuaMYp4IdGd+aeHJwWUdKxaK0Lds5c1iGAY6i6YsLPt0wSqARPmNVvGXMh2d8rEdyKigcjo03CBFOpsb/EhJIkmYPKfs7NF8ytOUZQIdO2TWKBDb+JYNqZo19Qs7i3HQhDtld35UD43+S0vA== 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=zj629QuraNxxO6GbeRTz0l7pFelQiOG3qWST6r/v/Ug=; b=Hw3dLPgk/h+8Pi7bIE0f4DgS8vFzD5NF/JvG8bHQ6Dn0SLOH7pj+G0cmvC0WxYq9g4kYoqHN+mp/smAOvz27WnFkS6RPp1crtIUDMTfjYzohKm7vjcQ/Zwd0gAd5OB/WQTYuJIgN10QTEbbaS0sgH6VvL912/NYTyOuUMdHJ7mU= Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=amd.com; Received: from DS0PR12MB6608.namprd12.prod.outlook.com (2603:10b6:8:d0::10) by SJ0PR12MB5662.namprd12.prod.outlook.com (2603:10b6:a03:429::9) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.8093.17; Thu, 24 Oct 2024 04:01:13 +0000 Received: from DS0PR12MB6608.namprd12.prod.outlook.com ([fe80::b71d:8902:9ab3:f627]) by DS0PR12MB6608.namprd12.prod.outlook.com ([fe80::b71d:8902:9ab3:f627%3]) with mapi id 15.20.8069.027; Thu, 24 Oct 2024 04:01:13 +0000 Message-ID: <12f51956-7c53-444d-a39b-8dc4aa40aa92@amd.com> Date: Thu, 24 Oct 2024 09:31:01 +0530 User-Agent: Mozilla Thunderbird Subject: Re: [RFC 02/14] x86/apic: Initialize Secure AVIC APIC backing page To: Borislav Petkov Cc: Dave Hansen , linux-kernel@vger.kernel.org, tglx@linutronix.de, mingo@redhat.com, dave.hansen@linux.intel.com, Thomas.Lendacky@amd.com, nikunj@amd.com, Santosh.Shukla@amd.com, Vasant.Hegde@amd.com, Suravee.Suthikulpanit@amd.com, David.Kaplan@amd.com, x86@kernel.org, hpa@zytor.com, peterz@infradead.org, seanjc@google.com, pbonzini@redhat.com, kvm@vger.kernel.org References: <20240913113705.419146-1-Neeraj.Upadhyay@amd.com> <20240913113705.419146-3-Neeraj.Upadhyay@amd.com> <9b943722-c722-4a38-ab17-f07ef6d5c8c6@intel.com> <4298b9e1-b60f-4b1c-876d-7ac71ca14f70@amd.com> <2436d521-aa4c-45ac-9ccc-be9a4b5cb391@intel.com> <20241023163029.GEZxkkpdfkxdHWTHAW@fat_crate.local> Content-Language: en-US From: Neeraj Upadhyay In-Reply-To: <20241023163029.GEZxkkpdfkxdHWTHAW@fat_crate.local> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-ClientProxiedBy: PN3PR01CA0045.INDPRD01.PROD.OUTLOOK.COM (2603:1096:c01:98::8) To DS0PR12MB6608.namprd12.prod.outlook.com (2603:10b6:8:d0::10) 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: DS0PR12MB6608:EE_|SJ0PR12MB5662:EE_ X-MS-Office365-Filtering-Correlation-Id: 5c9c650f-be12-4e81-479b-08dcf3e0804d X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|366016|7416014|1800799024|376014; X-Microsoft-Antispam-Message-Info: =?utf-8?B?V29Md0pBTWlXRFltVUJhaktxcnQ5S0FrOUpUSU9rMVd0TWFuS25VNGVwYlNi?= =?utf-8?B?ZUt1ZkdKUzFIaldWZG1qc0o5NCtUSDJUU2RETzNwR3V4YVlBaEFnaFpaUG1a?= =?utf-8?B?dmQ5WGRHWDVnenlMSFpTZnNmRzJuOEF4NnkwNGxHYXhQcWFlbUZCaVFYeWI2?= =?utf-8?B?WnRZK2p1RU5lSFd4UTZUQkNpSkh1RjF6QmxYaUVEVjJtSXpLcmRFaHdPSXlF?= =?utf-8?B?T3pTL1ZrbUw5c2ZTWjlYbnBQeTNiang5K0hMSWZFSFJRWWtYNnROdG8vNDZS?= =?utf-8?B?anRzem1vTE91eDY2S1pXTnZZb3BRYW1uRk4xRjVrb2FUU2JJUklNMzNhT3J4?= =?utf-8?B?QStld0FQNkxMN2tvZEUrVlF5em8vc1hhb2hEcXJWV1RGWTIzYzg1azdrd2Jx?= =?utf-8?B?NDNqQlJnYjFXNXFSeU12bE1vYVdIMUhWQU44TFI0Tml2Mkx4ZG1QZ0VyZGZa?= =?utf-8?B?ejIxd1pKbGpWTkk0Nk5mZVNSSk9PbUZLZjRUcFFMMnVuVGtDUzVrZlpWNUVW?= =?utf-8?B?STF0S0xJV3U4aVp2Qy9FTVcwNmMvdXNBbHgzdE1GSXcvLzV5Rm05OGxiSjY3?= =?utf-8?B?Z2g4Q1NBODF4ZmZDdmhuVkJrVzc1R2VnbFpZVlZwYW5mQW5WdEdXbGtXaUZt?= =?utf-8?B?MUlVY204K3lUZm13SFJRcWJDYUxVQzhTcWRoWkVOcVkyVHpKYlZhcm0vRUZn?= =?utf-8?B?Wkw5bnB2UWJmQXhCUldvdjdaTlZoR2FIN3JmeXlJTENnNklZdFBNNlBweXBh?= =?utf-8?B?Q3JRSWt2YzlYeHNBUWtCSFNjb0crL2VyMnRPc2VrYjVidmtnT2ptQmlHMS9K?= =?utf-8?B?RHBxZEdwNTVrUkJQeE1oVW1kVWxuU3duTE8wQzdRcG5HcnIzUDY3b093SUZM?= =?utf-8?B?NzBURTdKV1lVZzdmdlhESGh5dFRpQ0NZMW5IVHd0RXc4YTM5MnFtd0RVUkpF?= =?utf-8?B?eUYzNVdGYnQ1TFhLRGY3NXF0OFc1cHZmemZ0dGkwTFk0OHVVTEJJQUw5K1NC?= =?utf-8?B?NDk3WTJYeE4xMDIzUUhqNGpVZ0dJQlJPZjB2cmNZenArVEJZcHN5c1drMENP?= =?utf-8?B?VjVUOW9ZWnJHUDZYTkNjVGhvRm12M2w2VUFzSmFlL2FVVDlEMzU5TUlSQVBU?= =?utf-8?B?eWRHbG5yYnNhUkJNQ3BTakVtNnJzT0JweEM2RnJOc3VLSlpIYjdVaW80NFBY?= =?utf-8?B?elV6ZFNkTHh5T2VVYWhiaHpERUR1VXR3TDJPYm55MUd4WnVnTGhCZFE3MTd6?= =?utf-8?B?bnBnTjNSREtUQkdqZzdhSXVGZVc0cXltTmZ3WlJaTHRSdnRBamU1RjNqSHMr?= =?utf-8?B?d3NpTy9jRi9ZaG9ZMEhPRjJvajlwRnNtZUJjZlpsVGE5L3lXQ0NnbkZqZ1hi?= =?utf-8?B?UGQ0elRmemJvK0J0Wk0raXhTQk9EV1NUU3VxZHNOWFd6V2JwUURXL3FNS3Rr?= =?utf-8?B?VnZ3dlhVdmtkL2NRMjZGV2htSGl2dlplcEFQNWlGaGNrRXU5bkNBUGJ4UGhh?= =?utf-8?B?dW0wOEk1bUJTWjJnM3NNaW01d3VvSDlwVzI4WG1FUnVlMjhpenYrU2Jwb0Jq?= =?utf-8?B?bTdqTUozSVFNK3hyTk9TckRtUEg2MW9mZGNMSnkvVmpscnZhalVsc3NlUzRG?= =?utf-8?B?K1h0Um03Q0V3cjk4VUlRc2ZsVytzUS9yYmhqcUlxTmlPOFp4VXdGRUVBTk9T?= =?utf-8?B?SmxUejNjeUtCM2xBNW81bHlYZUpGcUt4ZmVpTVVpTEd4bUJOTEdRU0trSmRL?= =?utf-8?Q?d1LEzUhshKPbDrD1kI72OE6LmExhQRfCy9AHHgl?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:DS0PR12MB6608.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(366016)(7416014)(1800799024)(376014);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?SWhJa3Q3cmZ6OGZBbnVQMFc3akw5U051Yy9iNVlYVjFQak5CWmtSQUs0MWtU?= =?utf-8?B?Uk5RUVQrNUcxeUNmWHI2a3c4NGRGZ25JQkRPZVdhYTdFR2tJVUdRZ3hHOXhR?= =?utf-8?B?L2IxMnRnWCs5UVhqbEJ1c3YxaDNQb09iTk1OVzJnbFUrN3M3VnBSNHZFeC9r?= =?utf-8?B?NitvK0ZpTEpxdUpNVG1xTTlrZ2dQYTRnejdOOEpWYUtNV25PSFJ2NmswQWVR?= =?utf-8?B?R1FSUW1zQW5MSVRlMFhpUHdqZ2RQR1puOXVoeU10LzIwbW9BQlhEZnNWTUpr?= =?utf-8?B?UlhBM21JdEpRSmVjTGRiVDM3Y2EybmFEVWh1MUY4Sm9qRjJxd0JCYmQ3U3RT?= =?utf-8?B?TFVUU3VXenNtbjhZMVRscVZ4cUhCdytBb2pNeVU5SU5qSUV0aVNzT0Q0TG1L?= =?utf-8?B?bXk0K3gxb2oyajZUSXdBS2lMNmJOQlFHcndOMnAwV2lhMWhsa3libUVyU1c1?= =?utf-8?B?dVZHOEg1N3lBRVlQU0FGNnJzalpGSzM3WloraTdlem94NlNuNGREOVBmUEow?= =?utf-8?B?aXdpdndIVHRyeExBZlNBUkkrZFVBTmQ1YXExSis3OW9LMmJRN2NrRFpwSk50?= =?utf-8?B?ZlNreDEzTUg0SGNra1pRUFN1VWxNZzZVcm1oMEdhWk04TjlWZW9SNitRRklm?= =?utf-8?B?NkhmWWlNM29IYThvV3B6YW1FQTZJbndUUU91SUQwUDdodFNIa1hjc1ZaUitw?= =?utf-8?B?MGxCejJPcjg2QVFaOGgrODd5SmtUTkN6NkhpYkYxMnN6cmJ6VTNPOVBrNVZa?= =?utf-8?B?Tjc2SUVQd05valR6UWNOd2dQbDR5NExCMEN4QWFzU3VjTXlwTnNzdmZVMDMw?= =?utf-8?B?d1A2SERoK0x1WXNTWUJkYWJGVUlmNG5PSEQrVEQ0L0NvZ0tIV2VqMytHT2VU?= =?utf-8?B?ZE4yYmdqZHNqRHFQQTFySG1uUWsxcE9JSEJkMlo5c01JaFY4T3JDR1h6M09x?= =?utf-8?B?NzVBcElBQ2dOZWc4UE5Gd0IyZnhMWFo0eGxFZUFoUS9USTU1YlVxbVFJaE81?= =?utf-8?B?TTU1Q0U4eHlPb1hpZDluM0lJSExFdkZDZDFLejd5TUNlSkd3cHA5djBYUFBn?= =?utf-8?B?NDdTdHBqL0ZSRHBmK0g2cmM2aFFMbEhCTUxmWHI0YitIVzRNVGNmcmt4TkFI?= =?utf-8?B?SlFiV3lKd3IzUWZ6eDlUcjh5eDZnZllaQ2dTbDV3eDV6dEN1UjJnMzN0VE9X?= =?utf-8?B?dkU2RUxGaWdXYjVCMTByR0k5bWpOMFh5SUdjSEpmSW1Rb1BkQVNIMmxuSFdk?= =?utf-8?B?NnRXS1prTXM0WE5tTmxHUnNQcEpSQVBNN1hRQk05TGVvczJhYmwrTjlOWHcw?= =?utf-8?B?ajVNV3lFZlRiSE1Gbm5JMHU1bDFkMFhsL3ovZnEwOExsTWY2MWd2SjRsNDlt?= =?utf-8?B?cm80OTA1Y0haZEhNZnF1VmxWdC9ncnZPM0trWXVQQS94RVdCcVNQWGR2UCtx?= =?utf-8?B?L1hJMkVVZ2NTZG96bUVEWFYzaVZYLysvdXlndXp3YnM0ZzNTOVZKL3ZPdmNj?= =?utf-8?B?ZHVIQjQ0WnQ2WC95MEZFZkVzQ1NaOWNucGc2WklIWmRURmRscGVDS1Bkc1FQ?= =?utf-8?B?T2ROTGZCWHdDcmQ3N2FVS2ZyRU1waFhYUVIxcVg0RjVEZkZUY084ZThMcG1p?= =?utf-8?B?WmhQZGQxeUozZU5TbDlJRXBGMGlwaVJXWERlQjl3WkRZVWpCRVRCSG1wRG5N?= =?utf-8?B?K3FBcFBQdXRVU3dtQUl4V2x4MEdqR2ZuOSsxcUFmV3c5ZzZNZm9lQThwNmQz?= =?utf-8?B?NElhRlV2RU81encydTBDTG00Wm5tTDB3UW1QUTY1b1k3QXp4anJVN1ZpbnFQ?= =?utf-8?B?ZVNFWFVPQkowczJkR2QvcXJRanppam53NmNPcFhmY1gvK3AzQjl4aDIvUk91?= =?utf-8?B?MTZ5UHV5N3RYVWVla2tTSGJtQUdRWldNcXpNUTMxb3ZYV1l2cFRubWJrcUc5?= =?utf-8?B?OFR6NVBNUlA1QXNRcXJ1Y21IMDJhRVY2U1NiYlJLUHJKVkVuVThXYUQ5UUQw?= =?utf-8?B?Z0szQ1B1Wm5xMDRNNFNGdlRhZEFHekw5eGxSNXZWdnVDMTZnemVHL0NiYnpX?= =?utf-8?B?dERKNmI1cWUwSlBsSXI0WVI0SXIvRjRSL2x0ZXdYRUxzUE53dE5lRXorVUFk?= =?utf-8?Q?5Lx3pDTjFu+lb9Tv8HOfMkHV7?= X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-Network-Message-Id: 5c9c650f-be12-4e81-479b-08dcf3e0804d X-MS-Exchange-CrossTenant-AuthSource: DS0PR12MB6608.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 24 Oct 2024 04:01:13.4636 (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: qkYOOfRYpse3zgLPNqARHHLVhiCDSemxRz0/dJsxtXbU/0aDGVhv+nBZ7KxIQRlzItXdN2Ob21Cm20gwEYqf0g== X-MS-Exchange-Transport-CrossTenantHeadersStamped: SJ0PR12MB5662 On 10/23/2024 10:00 PM, Borislav Petkov wrote: > On Wed, Oct 09, 2024 at 11:22:58PM +0530, Neeraj Upadhyay wrote: >> I will start with 4K. For later, I will get the performance numbers to propose >> a change in allocation scheme - for ex, allocating a bigger contiguous >> batch from the total allocation required for backing pages (num_possible_cpus() * 4K) >> without doing 2M reservation. > > Why does performance matter here if you're going to allocate simply a 4K page > per vCPU and set them all up in the APIC setup path? And then you can do the > page conversion to guest-owned as part of the guest vCPU init path? > Please let me know if I didn't understand your questions correctly. The performance concerns here are w.r.t. these backing page allocations being part of a single hugepage. Grouping of allocation together allows these pages to be part of the same 2M NPT and RMP table entry, which can provide better performance compared to having separate 4K entries for each backing page. For example, to send IPI to target CPUs, ->send_IPI callback (executing on source CPU) in Secure AVIC driver writes to the backing page of target CPU. Having these backing pages as part of the single 2M entry could provide better caching of the translation and require single entry in TLB at the source CPU. - Neeraj