From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 71CC1C83029 for ; Mon, 30 Jun 2025 14:05:46 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id E4A4A6B00CC; Mon, 30 Jun 2025 10:05:45 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id DF9C76B00CD; Mon, 30 Jun 2025 10:05:45 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id CE9106B00CF; Mon, 30 Jun 2025 10:05:45 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id BF1566B00CC for ; Mon, 30 Jun 2025 10:05:45 -0400 (EDT) Received: from smtpin05.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id 88A03BA0C3 for ; Mon, 30 Jun 2025 14:05:45 +0000 (UTC) X-FDA: 83612240250.05.02C6EF1 Received: from NAM12-MW2-obe.outbound.protection.outlook.com (mail-mw2nam12on2041.outbound.protection.outlook.com [40.107.244.41]) by imf15.hostedemail.com (Postfix) with ESMTP id DC50EA0004 for ; Mon, 30 Jun 2025 14:05:42 +0000 (UTC) Authentication-Results: imf15.hostedemail.com; dkim=pass header.d=Nvidia.com header.s=selector2 header.b=r3v3OKIJ; dmarc=pass (policy=reject) header.from=nvidia.com; arc=pass ("microsoft.com:s=arcselector10001:i=1"); spf=pass (imf15.hostedemail.com: domain of jgg@nvidia.com designates 40.107.244.41 as permitted sender) smtp.mailfrom=jgg@nvidia.com ARC-Seal: i=2; s=arc-20220608; d=hostedemail.com; t=1751292343; a=rsa-sha256; cv=pass; b=PJ7W78uscJkTTeE8QjLWTXN4HXO5wt/6TZrQT6DOthsmQaLXanoBPLcf6+PsfCF/KEU0Ir D7R35f+bzwQACrerJ71FkScCa2ncXP1ebo7QR1TezSCCqWNn0fZGNcUIkv1e/F1LpqJd2J 90+haWMZkJSWrZaE7cQwkZHCzeeHbQg= ARC-Authentication-Results: i=2; imf15.hostedemail.com; dkim=pass header.d=Nvidia.com header.s=selector2 header.b=r3v3OKIJ; dmarc=pass (policy=reject) header.from=nvidia.com; arc=pass ("microsoft.com:s=arcselector10001:i=1"); spf=pass (imf15.hostedemail.com: domain of jgg@nvidia.com designates 40.107.244.41 as permitted sender) smtp.mailfrom=jgg@nvidia.com ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1751292343; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=4/KdEzzURSfQczH+RWTMDG580fTYDJA/Wb7a4rd0mps=; b=KclU+FzF7viwi6DLSlbRZYl5AkxHWjyK/cMK9b5q8AdbBaGKIrLZm0exxknMwyKQCUg2FB ZqLz0JYErqgxYUeHojM3HXwIo3Q7JDBcj+HDLymUGlnSHQ78fFiTorhTcRbdEyWwa1pwfD 9OwFuYHVQaFs367bIfHrlPXZ6a4CRS8= ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=CFeZGBC44Eru4540YjSpKW26l0BgqYm455UNs4fTgzNtWGzF/E/7LhqT9ZfaqEHm874QgprMrdQsLPZAoMWaG05tYrQJAkjV1r3PeTzpN4nSAJ8CmF8yGQeqEssXv24NIa+zxRsVT2sf2znTUabllEYV3gl9glR3dJPFQKTpDjkU36GIY9Phao58F2sv4jomuJCqfYRYaA0cpbLzTsHJ+jVAO6MsFREdV2/2mTwLhpVk6WDuVbaLDwZW0uUKKVZaskQ55U/+F5zpyL/gKuqGGtEwKuvyVeGFl/CsPlNb4IhqJ0f8UkiFhyFmabAXC4rMlc3Mv9N7tnDxFGbzs0uCjQ== 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=4/KdEzzURSfQczH+RWTMDG580fTYDJA/Wb7a4rd0mps=; b=HWigZbvWXY8WJnDe/6HyLQ0SR1Mul3lrjK8dL2cBWRYv54x5UXlN/KRmFvXUOozkEaI3IekMQAdQvyA3fHDsxctzTiFNakY52SrpGi0IL92XXv0xYqttCczkL5GEVajoBKeT4NPKB5N6PmS27jf/FwYTeoYmJVVl9cYB//6xjgjoaWBLWks8OiJgeCRTeq3yWWo2CGyw+ypIjn6MXa4geB9PD6rJ7EgINMqO+n2YE3V7U0LdGP7WOWDxjZud1ClVM+QD1B2CBCF9q7iwuKPwfKFzjaBuSUAy5WBE/LGac2k9CCdKX+i4WQneQ9qceEKwR9BpVH0NH4HkQkEMZzPV2g== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=nvidia.com; dmarc=pass action=none header.from=nvidia.com; dkim=pass header.d=nvidia.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=Nvidia.com; s=selector2; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=4/KdEzzURSfQczH+RWTMDG580fTYDJA/Wb7a4rd0mps=; b=r3v3OKIJAS13FBFqMVjkLbB9+gOXPkyRoSeq1UVvHbgtcqFaG6quDJ+LcRPkEcULNwqqfoxFoqMM63xPooi2DyDf7QQmkcSZvhryzYFI1kSI1QTXshd0iwygU1NeMBFmFx6zl/9Uu53derfS5lC+uNf2nBf7biaSXzyYC5qf9KBVW5u5apBYCO0scNR4Oe0GxoEODxA8HI+GyqbvzEo3fiIAQ5sum684/oVwA34RuOtDyLgl2gnOdmFMKsd44pEm3YMjDb2gf54cWUI9UB7OMToNPEsLkNrWVdgbEdIU80OTXkONF+2AwD1qKL8UPI56GRbK8xAXt08HD68pYCSqfA== Received: from CH3PR12MB8659.namprd12.prod.outlook.com (2603:10b6:610:17c::13) by SJ2PR12MB8035.namprd12.prod.outlook.com (2603:10b6:a03:4d3::13) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.8857.28; Mon, 30 Jun 2025 14:05:39 +0000 Received: from CH3PR12MB8659.namprd12.prod.outlook.com ([fe80::6eb6:7d37:7b4b:1732]) by CH3PR12MB8659.namprd12.prod.outlook.com ([fe80::6eb6:7d37:7b4b:1732%7]) with mapi id 15.20.8880.030; Mon, 30 Jun 2025 14:05:39 +0000 Date: Mon, 30 Jun 2025 11:05:37 -0300 From: Jason Gunthorpe To: Peter Xu Cc: "Liam R. Howlett" , Lorenzo Stoakes , linux-kernel@vger.kernel.org, linux-mm@kvack.org, kvm@vger.kernel.org, Andrew Morton , Alex Williamson , Zi Yan , Alex Mastro , David Hildenbrand , Nico Pache Subject: Re: [PATCH 5/5] vfio-pci: Best-effort huge pfnmaps with !MAP_FIXED mappings Message-ID: <20250630140537.GW167785@nvidia.com> References: <20250619135852.GC1643312@nvidia.com> <20250619184041.GA10191@nvidia.com> <20250624234032.GC167785@nvidia.com> <20250625130711.GH167785@nvidia.com> <20250625184154.GI167785@nvidia.com> Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-ClientProxiedBy: SA0PR11CA0153.namprd11.prod.outlook.com (2603:10b6:806:1bb::8) To CH3PR12MB8659.namprd12.prod.outlook.com (2603:10b6:610:17c::13) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: CH3PR12MB8659:EE_|SJ2PR12MB8035:EE_ X-MS-Office365-Filtering-Correlation-Id: 6718bb7c-90ff-4613-68fd-08ddb7df3128 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|376014|7416014|366016|1800799024; X-Microsoft-Antispam-Message-Info: =?us-ascii?Q?XyUbJzKq6sjNvu8H4dsTArBcxEQMKC72uQrZcjIgh3xVLwrkAvWfJqzXpukX?= =?us-ascii?Q?B8SUr1GKvAjaCMCUNikAtQ6zLafHg2ETWOtKRNYfZYUjNTANrO1CkuCz93Ba?= =?us-ascii?Q?2Kcw7GwM7BcAyU5BRZb/rS5gXHtDh0gwIwu40IOHBWB6b3Yvd9u1fjDvXpTz?= =?us-ascii?Q?MEWnvX/1aJiU88niabF3RR28pl9/DBVjA1RoucNxITbfF/t0i33jJS5lnPvZ?= =?us-ascii?Q?W8AWSGFNdmz08U48T+pi80TiMS2tp8ST09zD3qPeIeb9Y1ExzqsOYi4emU4n?= =?us-ascii?Q?FczuqlRPiRBjBD0SRrSWrNVGq2PTD1Of5qA8o3TEdF5ETheu5SVfps+kWDdQ?= =?us-ascii?Q?osOoSOCnk+kP5Ne1MmAnLXitnwSlsTn6wp3QjJhOWErBbdExaQOUllHHfDl2?= =?us-ascii?Q?a4o3Dgza3B/U2M3gUbBS0xXE/PCytf6W0Lj6zkAd3KqCVpvd+hiZWhLikmn5?= =?us-ascii?Q?1fmdTHVK/Q3Xz+22MVnKuuaq2JjxOg5cQN32vpV1qsm6GAjWorqY8/z0P+O0?= =?us-ascii?Q?Sj86I5txqUMf5NwOkUHjETM6FI5QZunz1/yxeCtUPLxSL9m+k5lzgj7a/lHv?= =?us-ascii?Q?phh3bqjEP36yN6BdDX0YNePDHb1rkmjgotyyELRepJXV6e20J0D7yk5AANMJ?= =?us-ascii?Q?ORCY9Gja/LVx2+pWprLP3iRGKojRyygQrIoyAWPFRurVFTL1GeYUgGN+ZnMu?= =?us-ascii?Q?8gvVBdCqO7jWogWfS8DcR0slY5Q5gwxSVyFDVLZt4tH+zB79+GY6S55p1LEX?= =?us-ascii?Q?jeqhDyzmYP48WdIbSSqoEOAfXj/o2Iv6aOjULTPHDMVaY2Q8sznqmO1Ij5Ru?= =?us-ascii?Q?oRQHhDcRdpBGMV7bkg3KMTOTop037593CPaakFSNMDod/+toFh4KePTgaC1e?= =?us-ascii?Q?V3AzuaTjCvbdDy2P/KzdC+kyYJiI1gXmFEwtKR3WBXKAx2XlsU6yyhglp8dH?= =?us-ascii?Q?9/WpdVxBPkB8xydLlUad3nky/AoLk6RDdC3abbU81KwuxAtPxo158kaAo+Ap?= =?us-ascii?Q?ZI71Mz/lvcVfzyfPc7D+IaSEWcFKCCNjr9BN606zWxrnNj5u3jMIZPg4rBui?= =?us-ascii?Q?S0igI/FhqDbj/uMWR9RqpeVdrYLZ2E2W1rBWqYCkXHIx+ph9FAErfK/E9AYv?= =?us-ascii?Q?kYYLTxfHXdLNHfPDeRSHWeKvibzK5SzkGLaNN0ufnKKa0eLitsXy4SkcJsZh?= =?us-ascii?Q?4QM4fR6SU5d7X8XIlcQGmbT1CE0L+PGEbQ6bpGTFkb4fgjQPEzoqxw75Qmvj?= =?us-ascii?Q?n1KMRJyZwLrJU8vHAZg5MNp7fV8rQimp3TnWd6jFQn9R66GoSnnsXwDPXG22?= =?us-ascii?Q?tWV9Xnzeh7vfh7sKEgDE0ZbHBevY6lTK0Jfuaoqa6E/nlMFlAgIIjGl3OYCz?= =?us-ascii?Q?dknjffzonDV1mWQwH333cP43Bi9CerWeqEcKSZn4xqk7Ty0qLzVUBn8upKXb?= =?us-ascii?Q?IfJbDxHpTdk=3D?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:CH3PR12MB8659.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(376014)(7416014)(366016)(1800799024);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?6dDg1lTVI7Q8teQlTE6L45VvkgrJzda6vW/Us7bWi6Ck9xlHNl23fQMO0T7m?= =?us-ascii?Q?XurX5k7eleh34nFiLeSk9IM6azOzhAOPsk7FiNl8AmYGHQgFocdh0vrEm+an?= =?us-ascii?Q?TjxRP6eFAACNF2DiLhQeUxtZI0reqx5hl6yIW9wKnPgG8cQHv8OWfyUEc3io?= =?us-ascii?Q?67Pf6mzFDaixdGsD4KdSPL+Mf/FRK/QZKJYSsSPvSxSbU3M9xPm+QtPKax7Y?= =?us-ascii?Q?Ac4Q3XYezUAuDBRtExmeniKaQIV7QUZa2R/gcnAjOmqdtKTLZavHRSqSHZdP?= =?us-ascii?Q?rh6buc1LcDudfkCbHjWhlKpA7T3RKRfSxI48LjEVc4rLGvVD7NEOY/a9rqja?= =?us-ascii?Q?RCoq9PGoqJXehPPNxy7s/BEJw2ZZZxLJYZNSpi7sVhTiwK+WwgVdrkb0YvZa?= =?us-ascii?Q?h4f7133r4CKoI3zQW5emcRBsj8hgbO22mouW6O2ax9pGN6OZzvowEcaKF16i?= =?us-ascii?Q?y+/1eQ8NcGhh0tYKaNU+CogWQI6CcSjbNAUXJAAG11LmdjzoZE0Zlx8atejj?= =?us-ascii?Q?IyroL6j95poQkcuaCipus1o0DgzVNMeAlMOhG25RmD098p8AWPIaabL5r3vU?= =?us-ascii?Q?VY/6E7DZgKPTO4EVKz1pD6quNMRXncPaQxwNuEEkxpVzFcOw9G0b+TYB0N9e?= =?us-ascii?Q?dzDkI6Hmggwx+5i7TlTKazgRlOqr6J+wfIIN9MBW4OOL26V9ZajjIr5MFej1?= =?us-ascii?Q?YlAJppUbarZNnYXH7ceSA2869/Gw8721ADFMnbNYLnV1CsChTldz6naxsSn+?= =?us-ascii?Q?kn73F/BW+ENg/IVT8W9wk0JLzV5g6/z7EEMI2rTdA/tb8Nj/m17hNfEAB74C?= =?us-ascii?Q?fYciMxkMpwQaxld+S334RaUpEeq86/NTlnrM39XKv3d3XE595moslH3+wyS7?= =?us-ascii?Q?U+djZgCQNaSiADb9I0E/j3Pq/eH/PC/Ba9CfEFOVeN0uKjIwTz0zzNlEZe2g?= =?us-ascii?Q?/Mv1gk1adqEEIHihi+zjH27eHPTxFVyiWcruQBhBCx2AMb1iOgyoSJOwUWgs?= =?us-ascii?Q?CSPil0s3VL5kXbbhmM5K8PFBg5vmo/qjLHUnctqBRBnrLlYdFzPQJJgEyB2O?= =?us-ascii?Q?i1grj4FrxvZDuX8MA1RH5Y7p3+qN1xaLL8T6zGI8c6es5ehoJXIhnurx2s5S?= =?us-ascii?Q?OHsun+f7TjKvHxbyzVt9x0gYPZ6d4W/7AEZLFmGq2qR9USSwN81F5NLAailL?= =?us-ascii?Q?AEK/ipnAvTXnqURkWhqofmNiS7Sz1GM8wOYZ8NTRfuf/Hb70IT0tqhzu/8KS?= =?us-ascii?Q?UcWpu1zCSRaePVXSiuqkpBDjPEHmbSLocpQ3W9TTphXhJl6E2wNve6R33Os1?= =?us-ascii?Q?7HfJtI5Gyv6GIL5DDWtgayMWWAZiFBghFjPswr1E/u+FU3EEmSXioecu6nHj?= =?us-ascii?Q?SpM9jZxkj1mP1qrLaM2NblKRKAarbtmQ98tU8THiAzdUnfUMljWMYD2S9BJQ?= =?us-ascii?Q?dGx0Ddwu3zMZQgPfbNE9zJCoGjhx+D3jfBlcufcjXLNfW7+eNLkEyUZwZ7RK?= =?us-ascii?Q?4G6c98nsOx9kGmbD1m8FcxIwf10wQxej+kMAoXut5OR3HmqgFv5vKlCRH/El?= =?us-ascii?Q?ZlzErfqEnZERL7O8QrSS24ayNA4/lj83iTBkNb1V?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 6718bb7c-90ff-4613-68fd-08ddb7df3128 X-MS-Exchange-CrossTenant-AuthSource: CH3PR12MB8659.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 30 Jun 2025 14:05:39.1007 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: f/o2mCclrBU7G3sVSyrWr6bvj5XszJQoQIxPFDeKKFR/i2x9JJzosqxz4nuJJCsF X-MS-Exchange-Transport-CrossTenantHeadersStamped: SJ2PR12MB8035 X-Stat-Signature: gb57respeksezaznfi9or54rbfy5mscp X-Rspamd-Server: rspam01 X-Rspamd-Queue-Id: DC50EA0004 X-Rspam-User: X-HE-Tag: 1751292342-152783 X-HE-Meta: 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 BNnUIk9Y v2bjqMoVXoCUzh8l8nKFtn6MN1k0HA2wVMtDNTyDAsuper4BXdGyHtSSRjw== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Wed, Jun 25, 2025 at 03:26:44PM -0400, Peter Xu wrote: > On Wed, Jun 25, 2025 at 03:41:54PM -0300, Jason Gunthorpe wrote: > > On Wed, Jun 25, 2025 at 01:12:11PM -0400, Peter Xu wrote: > > > > > After I read the two use cases, I mostly agree. Just one trivial thing to > > > mention, it may not be direct map but vmap() (see io_region_init_ptr()). > > > > If it is vmapped then this is all silly, you should vmap and mmmap > > using the same cache colouring and, AFAIK, pgoff is how this works for > > purely userspace. > > > > Once vmap'd it should determine the cache colour and set the pgoff > > properly, then everything should already work no? > > I don't yet see how to set the pgoff. Here pgoff is passed from the > userspace, which follows io_uring's definition (per io_uring_mmap). That's too bad So you have to do it the other way and pass the pgoff to the vmap so the vmap ends up with the same colouring as a user VMa holding the same pages.. > So if we want the new API to be proposed here, and make VFIO use it first > (while consider it to be applicable to all existing MMU users at least, > which I checked all of them so far now), I'd think this proper: > > int (*mmap_va_hint)(struct file *file, unsigned long *pgoff, size_t len); > > The changes comparing to previous: > > (1) merged pgoff and *phys_pgoff parameters into one unsigned long, so > the hook can adjust the pgoff for the va allocator to be used. The > adjustment will not be visible to future mmap() when VMA is created. It seems functional, but the above is better, IMHO. > (2) I renamed it to mmap_va_hint(), because *pgoff will be able to be > updated, so it's not only about ordering, but "order" and "pgoff > adjustment" hints that the core mm will use when calculating the VA. Where does order come back though? Returns order? It seems viable Jason