From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.16]) (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 B5ED435942; Thu, 3 Apr 2025 12:35:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=192.198.163.16 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743683753; cv=fail; b=QG/iSZzMtWrN3nfCe3JTuWJL1SAXI6l1YS+G4OdvUFM+XssU66LMLIWJgKRnJZ/U4e6RwxLhlOZX9v6t6NNM6bxivkZyBbivuhb447i65nUoi3pNyo1EOWG2d7uxnSKvlKYzEaLo20k/S5ffQ/LDxBJOQZ2S/OkIdjP2l/uUMg0= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743683753; c=relaxed/simple; bh=5E9ZnQr2odQy6iU7mesCMakpIng4posiu0AYDmjet1s=; h=Date:From:To:CC:Subject:Message-ID:References:Content-Type: Content-Disposition:In-Reply-To:MIME-Version; b=cc+/3wSBgej7jCIktsjerP6yiIQo39/W1MuEsPCHWR3jCwnS8zCfSpXM9RJctqdLAFWqBbtOIHa4+soeszCJg/FX7zshOx4JkEIqz1GGU2mqKlG/vbk6U7NKxYDLu87CA9enZRGN8FW6KdBJi3m4qdSJypsKf1yHPqXQTu4i3kI= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=JX/F8wIr; arc=fail smtp.client-ip=192.198.163.16 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="JX/F8wIr" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1743683751; x=1775219751; h=date:from:to:cc:subject:message-id:reply-to:references: in-reply-to:mime-version; bh=5E9ZnQr2odQy6iU7mesCMakpIng4posiu0AYDmjet1s=; b=JX/F8wIrJzMImfZ93YrZURx+CR2Pcj3wB2PSSnbR/TXHUcflBzXzjqgj gOpGej306582xFV1s/vMxFMyXyQ3eZ25tPfcyN/wV94fwXn99QiXw7cjt RTPT0pkaEIR8AfGmf2WAGeU5yC3KnKG/HBK/jstbuki1/UWZKvigFOgZC QidNKO2SvXHqcB8VfB/lPUVZRw6YqrhqSnUj0aUK+KHRnjsI3ZtKbifNZ Kh5vT0lNLV0UnGQg2Ub8MsG6qi/MjgAGRZaIo3IN35wTQlQItTfH3cYsR YKD92ruX/Ti4Jozd/UQvTueqvd0kFZbQP/yn0JDbIcuYPwxSeMH9YtLlC g==; X-CSE-ConnectionGUID: 3ULPC+0HSOyoMuvtCb6OKw== X-CSE-MsgGUID: 1bwKIQMnTJqcqM0qoeUuxA== X-IronPort-AV: E=McAfee;i="6700,10204,11393"; a="32690771" X-IronPort-AV: E=Sophos;i="6.15,184,1739865600"; d="scan'208";a="32690771" Received: from orviesa006.jf.intel.com ([10.64.159.146]) by fmvoesa110.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 03 Apr 2025 05:35:50 -0700 X-CSE-ConnectionGUID: 9mPk6JAeRhOBuwSTL99Wrg== X-CSE-MsgGUID: /hyjbmdfT0muLNhTCCJ0uQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.15,184,1739865600"; d="scan'208";a="126950414" Received: from orsmsx902.amr.corp.intel.com ([10.22.229.24]) by orviesa006.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 03 Apr 2025 05:35:50 -0700 Received: from ORSMSX902.amr.corp.intel.com (10.22.229.24) by ORSMSX902.amr.corp.intel.com (10.22.229.24) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.14; Thu, 3 Apr 2025 05:35:49 -0700 Received: from orsedg603.ED.cps.intel.com (10.7.248.4) by ORSMSX902.amr.corp.intel.com (10.22.229.24) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.14 via Frontend Transport; Thu, 3 Apr 2025 05:35:49 -0700 Received: from NAM10-MW2-obe.outbound.protection.outlook.com (104.47.55.43) by edgegateway.intel.com (134.134.137.100) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.1.2507.44; Thu, 3 Apr 2025 05:35:48 -0700 ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=mE7l81BGjwH2DFr6UqglNoiEKNHAIuY1bhT8oEToEIHSx3Qp5XNvB8AfaZ7aeIXUaYBJqv4F1cZF4E2OYqRvrG+wkc4Ykq5LW0FKiebLIcLXUDEBzh6w1TZ1Qz69wcwa2Tn7JzqtdRl6NLdFuqTqBzwvMl/b54UPS9OQufdnoU7q8Eu0kFoL9TeQh5EVVOLjMePwHrJY9zZ8Z0E5lITDBz3QUIzdEr8RpBskwODuEy40LBsmd/B5qsJbaPMqLO7xfqIGh3kVBzTsXQ8hc/cVtEUQProxR7IZTnBbFpNsFBLl24qgbu8TYYFZAZSr0lijNfVl0dNDOs1qmkzrBiONcQ== 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=yAaUxmFIAK5aQVU9l6tdF8waL0Qk3EXWnYRE9O/24yk=; b=t23duYy91Yl1yof0LnjG5NXnOEV4g+13pJyCGFCUmzDzhaT+8umRHBKeUbS0VJ6UlywTsIQfqB40Tfy5aCqJtmOlaoSvyrJQby/dcxrzygx4PykoGc4a4oTidxivrFcRycWQmLLUbuanQmT0sVSrizPN7/mFJxmQHp3Ueh2F6rX+tsJwOA9XvNF9ixIPABGWlPz/1H+tH77h5zw3jPsqhgHMhD1TRrg5hjEArcGZQctILAEb7yFInbBWVXRJbS2HZswwNq6wosqVeXN1q0NzyX2YlgZFMT9+SMWfWcvdgC0rB5BAoVPbIIi6g40gZm/b9bS/GBAiMXeysSZ5EkUpbw== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=intel.com; dmarc=pass action=none header.from=intel.com; dkim=pass header.d=intel.com; arc=none Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=intel.com; Received: from DS7PR11MB5966.namprd11.prod.outlook.com (2603:10b6:8:71::6) by IA1PR11MB7919.namprd11.prod.outlook.com (2603:10b6:208:3fa::16) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.8534.44; Thu, 3 Apr 2025 12:35:19 +0000 Received: from DS7PR11MB5966.namprd11.prod.outlook.com ([fe80::e971:d8f4:66c4:12ca]) by DS7PR11MB5966.namprd11.prod.outlook.com ([fe80::e971:d8f4:66c4:12ca%6]) with mapi id 15.20.8583.041; Thu, 3 Apr 2025 12:35:19 +0000 Date: Thu, 3 Apr 2025 20:33:31 +0800 From: Yan Zhao To: Ackerley Tng CC: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , Subject: Re: [RFC PATCH 39/39] KVM: guest_memfd: Dynamically split/reconstruct HugeTLB page Message-ID: Reply-To: Yan Zhao References: <38723c5d5e9b530e52f28b9f9f4a6d862ed69bcd.1726009989.git.ackerleytng@google.com> Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <38723c5d5e9b530e52f28b9f9f4a6d862ed69bcd.1726009989.git.ackerleytng@google.com> X-ClientProxiedBy: SI2PR06CA0018.apcprd06.prod.outlook.com (2603:1096:4:186::8) To DS7PR11MB5966.namprd11.prod.outlook.com (2603:10b6:8:71::6) 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: DS7PR11MB5966:EE_|IA1PR11MB7919:EE_ X-MS-Office365-Filtering-Correlation-Id: d31d6b8f-b994-4bf9-1aba-08dd72abfe68 X-LD-Processed: 46c98d88-e344-4ed4-8496-4ed7712e255d,ExtAddr X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|366016|1800799024|376014|7416014; X-Microsoft-Antispam-Message-Info: =?us-ascii?Q?qXyx+j5Mo2J+jDkeoiApSW2C2qTuE4IPXSaVrEmcFbCywU/9AYhJmFmn3TSw?= =?us-ascii?Q?3xNbyXOae3412z7HsO2qvaWv/BuLBlPvuQdbqn1E/D+1NJ3ZOtE2ayfpJom1?= =?us-ascii?Q?VWJvtjcVUPWs6LnKcQkSynnXjUotLa6KVHyrlcJeFzZJbLljDor2fgG6/B8H?= =?us-ascii?Q?CAZJO8gWRTPLrMGThh3cK3UpSpn8ENq+UTySMSOb42k9cz+eyQcZ0QGQOR4H?= =?us-ascii?Q?Il03wf72g6It1/Gz0/VS4Ax9uhwE0Jyj8cvRizbwj1dFtRT9G/oJS0oextQj?= =?us-ascii?Q?S0E6vquGlXAEkoSahLhgt5O/H49s6h/RgH0ToqaPdhbkP781Jgj3hiJ7s1I4?= =?us-ascii?Q?yHwmHUXvI5ivW4936YIsUd0RdnSmtu6IwAQo+wO8DSNEGzzzX2tM6OhFyhY4?= =?us-ascii?Q?z8rOfH7AlEiiZ9jrSk9ewQncacqKqTkPdSl56qEmyNaYumceDWeEiPUXkwEU?= =?us-ascii?Q?4IvbhYnDE+n9TEkURbgXy6roGwZGcmzdU/b6/7JSZKHdCp6lXLi9JBkW0nyx?= =?us-ascii?Q?SWnL2zrsRbQgd1MtoNSgYUOkFBByDcUrl7RWn2EtjeW3x6YYaabtBIqaQ2G4?= =?us-ascii?Q?uPWj2oDBYY8DdRWXq7x9SRckls0suvtj3Er715Qb4UDRUaAawAMX7QLtiDN4?= =?us-ascii?Q?pZqpp5KsKr0lcqmUhZsvEwe01iHhI4p1oVUwXlOf4LwdMi920vpj3lZGzzWI?= =?us-ascii?Q?2OvkoxIqW6b8D+3NqRUL+U+GyIqU+IGXHSZqZTsufPJKQrVNz+xp18ScuUtv?= =?us-ascii?Q?lpQZu70NPLgk886K/gGD6cSyH6Mri+USnbti2N6D5xCItkcIYB/iCIbDsOmV?= =?us-ascii?Q?6relM+MdPEPO7dNtZclQEqXTl0RyqFg1XTPts1FlBv+kdEmcf5AjqiL8wpEj?= =?us-ascii?Q?Bf0hrk2JGOL+mx90S569pWE0bvI7cPycSXmy0nH2XhKXuZfBHPUm8Bn80Yql?= =?us-ascii?Q?WenB3c375YadhQIiE8xbirrWbRw4GGVliPNZ3Aq5Xa8bHzN7/r/+Bi68HO7K?= =?us-ascii?Q?5httIPay5KE8IHYD8x3TT1spCHqflJufm+ejjDmhAf9AHlSjFhb2r0OTerv5?= =?us-ascii?Q?bV/E6teEHpMmo2DAYEE+rQRmGKo2SPF7K2G4vtcY0HLUmKELPRPsJs+B6ejW?= =?us-ascii?Q?V6FdSWSWoCMIPNOcmR6gMynRRCDL/TETJtcqd5aGnFZQDbfGQ+w4eDkbTI+S?= =?us-ascii?Q?/PW93f1D/+967X4McVS6qWOUlu+5Yu7bN3RCvhUtg/o184on422gbOuDYpOz?= =?us-ascii?Q?pmITw22GamvnZnHAlnSExvB7+mheG2SW/MH2iCOfblwxH/Ouz2UqO+bDqoEK?= =?us-ascii?Q?f+JLQKL1weWswRQCYfHex0smmXryq7R3s8CjDCN9N6OwKsvLt+FdZxtyfHF3?= =?us-ascii?Q?WZK8TExQnfhfQJoMIi5G/+0fuY+Y?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:DS7PR11MB5966.namprd11.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(366016)(1800799024)(376014)(7416014);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?6Xxf8yBcH5Etmo87onIGC/chovSrxFQ7cBOcwHpoO7IuTRZEMeNp3OX6l4a4?= =?us-ascii?Q?qQ15eaG/rrJhbjTVSV/tzHQttDynRuIEGECPaaQJw0gcqk8sPdXFyMTbWwrl?= =?us-ascii?Q?jgRNc8gqZRUbRg9t+Q8AmYDsY9aIwQ3/Ayh0GBlxZq3mtd8S3KEKf0nMf9/2?= =?us-ascii?Q?8WtetgsBrs0VAj60B50QT0BWiVk7hsUI6nB/rfcTrFLkqSLVEA9XqNoCCDhs?= =?us-ascii?Q?pKbmxSHTGOwI7vbmoKCh4rqSIlAhLm9zA/CUnYLNOL5vGihFW3mf9xisCJa9?= =?us-ascii?Q?fQ9Npe5oD3G7SxE321YBJDBnCiF0h+YnkKk8Vx4QOpCi90SG7wKqL/wPbE0f?= =?us-ascii?Q?j+yEMK5uvJj/2QMbjoqCAzm+BoQmV/fdZ4BOSX0+u0oTZlhOUw7ooRm4sd6W?= =?us-ascii?Q?y26n030fICvjYM5PbPI8yO+qLS84cWDx3bzJ0QvT3MjGgKchnu+1KF9WOkeS?= =?us-ascii?Q?fWshVCoT6LyIn0u7HKbJ/ZYq9pM6LGuie/Mh8UZMZV/W5ZlcI6/4yeeP0R9N?= =?us-ascii?Q?yV4iuVp8cu/Ku4NOPlpcsa0GwjrSwq4kRiB8xGJbJKGSIg3Eg1sYgrNS69ql?= =?us-ascii?Q?CV6NGXRgzN7IKZ0uYXun4YkMVaSb2prsoyyXfyBK67TssVjcSbf0S8/cs8+Q?= =?us-ascii?Q?33XCFkvdmLHftAJ9MCue7+SxjKhzfeNN5XqM//ZD6y66FHkoaKB1ns/4xEzs?= =?us-ascii?Q?O7f8c1nZMmRsrMFst93zb4PTpgQsQht1cvWU84Gx3KlJMWRGJL3rj1JV/ry0?= =?us-ascii?Q?1dOBtBrw6HXre5cexZmK25CukQasb6qrtqaw59UvGcDrjyA0/DsjURIz4ymO?= =?us-ascii?Q?mcDwDMwrtoGpd/BKYmeFDJX0Ri8b6zbZGe419NRDRjxiY9pHI2VQRELt0KaU?= =?us-ascii?Q?uwMoiNUWzLPjaPEW3YoUTD0Gt5E0Gq1rMnfrNeL3lFXnyW8ZcrmNBXXswUzD?= =?us-ascii?Q?UfXfFOZphNX1DrVP9cwYBB3w9yGvduXEJMTKCvksNuVc/4/Le+68vwNVikXk?= =?us-ascii?Q?GBr2R5x9qMO5+OQEQ35qSpXNyzioAbMV6UoZF8nqw8P10cjrxMduRsSyovsp?= =?us-ascii?Q?72Y/VvXyZg9iW0eMPpK0prf9DexquB0NWqmRKnCCHCa6Ycemw8YKNb3JGmRF?= =?us-ascii?Q?GF0OiZE1PEcYOuQogsEFJfrG8XWioE4VKXM3r9maolc/7G7QSdl/LwCZLZxU?= =?us-ascii?Q?XM4tp7nghh8MJB2rVS/gAvcrRpPh5m2LRcFYqn+eMW9HGULHG0Uyqsi7pd2L?= =?us-ascii?Q?GEsqSxdgW/24J8wGy6Nxke7uUmPnbACc7U65/xcyuGihFYUT5n4hlVpbaEI3?= =?us-ascii?Q?L80d/pD3rV8eX2fnBgodZFMDcaZKDxsA0NKzoLAnQb8coKYQ/a1OpL0zocYQ?= =?us-ascii?Q?CeXZt9d6jYqHP9CDb32jzrNCdN6NFSPLulMtuAMpDHNu6lPkSU/PrakE0QX7?= =?us-ascii?Q?xXzUZXa26vW/v+I4YMq4GVEi50jdpAm+GjfQLEeFz/bA7VnmNnjqhnBU9eGe?= =?us-ascii?Q?hlKDNIEW9NCYm6o+Iy/yYn3HPC68HuofzgAkFDlgfUEClhyZ2C/neuE/t3OQ?= =?us-ascii?Q?wx6VmDlaeBHNw2iViG+iuG2jy63b4DO1bTnAgB9G?= X-MS-Exchange-CrossTenant-Network-Message-Id: d31d6b8f-b994-4bf9-1aba-08dd72abfe68 X-MS-Exchange-CrossTenant-AuthSource: DS7PR11MB5966.namprd11.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 03 Apr 2025 12:35:19.1862 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 46c98d88-e344-4ed4-8496-4ed7712e255d X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: fjwQ6GnSKDDwqPx6pq0VTTcW87goFidti/+BoZebVG4flvtFpb2qJWsqm9qZdWnVqwmvALbhLJd9JffaO7y3Tw== X-MS-Exchange-Transport-CrossTenantHeadersStamped: IA1PR11MB7919 X-OriginatorOrg: intel.com On Tue, Sep 10, 2024 at 11:44:10PM +0000, Ackerley Tng wrote: > +/* > + * Allocates and then caches a folio in the filemap. Returns a folio with > + * refcount of 2: 1 after allocation, and 1 taken by the filemap. > + */ > +static struct folio *kvm_gmem_hugetlb_alloc_and_cache_folio(struct inode *inode, > + pgoff_t index) > +{ > + struct kvm_gmem_hugetlb *hgmem; > + pgoff_t aligned_index; > + struct folio *folio; > + int nr_pages; > + int ret; > + > + hgmem = kvm_gmem_hgmem(inode); > + folio = kvm_gmem_hugetlb_alloc_folio(hgmem->h, hgmem->spool); > + if (IS_ERR(folio)) > + return folio; > + > + nr_pages = 1UL << huge_page_order(hgmem->h); > + aligned_index = round_down(index, nr_pages); Maybe a gap here. When a guest_memfd is bound to a slot where slot->base_gfn is not aligned to 2M/1G and slot->gmem.pgoff is 0, even if an index is 2M/1G aligned, the corresponding GFN is not 2M/1G aligned. However, TDX requires that private huge pages be 2M aligned in GFN. > + ret = kvm_gmem_hugetlb_filemap_add_folio(inode->i_mapping, folio, > + aligned_index, > + htlb_alloc_mask(hgmem->h)); > + WARN_ON(ret); > + > spin_lock(&inode->i_lock); > inode->i_blocks += blocks_per_huge_page(hgmem->h); > spin_unlock(&inode->i_lock); > > - return page_folio(requested_page); > + return folio; > +}