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]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 66218FD0062 for ; Sun, 1 Mar 2026 19:22:49 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id ADE9A6B00B3; Sun, 1 Mar 2026 14:22:48 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id A8BF96B00B9; Sun, 1 Mar 2026 14:22:48 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9609C6B00BB; Sun, 1 Mar 2026 14:22:48 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id 844506B00B3 for ; Sun, 1 Mar 2026 14:22:48 -0500 (EST) Received: from smtpin19.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 22D1C160728 for ; Sun, 1 Mar 2026 19:22:48 +0000 (UTC) X-FDA: 84498466416.19.815ABD2 Received: from DM1PR04CU001.outbound.protection.outlook.com (mail-centralusazon11010056.outbound.protection.outlook.com [52.101.61.56]) by imf23.hostedemail.com (Postfix) with ESMTP id 64D6D140007 for ; Sun, 1 Mar 2026 19:22:45 +0000 (UTC) Authentication-Results: imf23.hostedemail.com; dkim=pass header.d=Nvidia.com header.s=selector2 header.b=c2+ypVPX; spf=pass (imf23.hostedemail.com: domain of jgg@nvidia.com designates 52.101.61.56 as permitted sender) smtp.mailfrom=jgg@nvidia.com; arc=pass ("microsoft.com:s=arcselector10001:i=1"); dmarc=pass (policy=reject) header.from=nvidia.com ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1772392965; 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=viYAM9CMMrheWaoJAuhbUd7ugZDuQps4PQRsLmCMHtY=; b=jL+G3h0b7kfLZaCKYHBF6af3NZ5BYs8s8V5t0ItGfNAt+d8esqooOuhzMcSLPHCSfzkXaY ZqyeLpGO4FpKY7G7rroZbftqVct4HuQkVVd9rtufLFuBb/sCEccIamsIaTBxqnPZ+ay7Nq 2llPmnoCkIaASneEmQkLq/qWuEFIjkA= ARC-Seal: i=2; s=arc-20220608; d=hostedemail.com; t=1772392965; a=rsa-sha256; cv=pass; b=Dzw3N6FqB4sItfY1yKLLpCFUx+RO6yh4R3l/+k7XnmbWw3xrzesCtlA59/iU88sw54knkX Avz+SiMuhB99f6foMilAUcPtlAQfvJP+rue1q2Ea+yySpZSWiHEBWKTvMNuXvXo0mCEkJd xMcLiqYzJSFYJ/thwPpF5MGb7XlAvnM= ARC-Authentication-Results: i=2; imf23.hostedemail.com; dkim=pass header.d=Nvidia.com header.s=selector2 header.b=c2+ypVPX; spf=pass (imf23.hostedemail.com: domain of jgg@nvidia.com designates 52.101.61.56 as permitted sender) smtp.mailfrom=jgg@nvidia.com; arc=pass ("microsoft.com:s=arcselector10001:i=1"); dmarc=pass (policy=reject) header.from=nvidia.com ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=dkWNq30D194C6xvSahys8Tqf3HbejmBTTsnPGc44ZNPKiM1EJawSSzZdz+R4tP0Er5S2Mln4XBct3sxHnUl3z4Eq8E6w6y6nYN/77MttZcS7x2FJt8hlz+myupAIIjX96tb0+zi/PaCVhxpjjv8+ZX4qoRn+qCrvCwVG1rBqZ/5SRakuzoy+Xos0tAJWlSx9R8CrCYcZEccw1XbNZ77aZkO85JYhWBDcBN13PROy1Lz/yfthl9GObP7qNgRaKLIaRs2iPmJqiffkSK26vpIe1GqXc2g7GH1oWnO1WRn6TLE15VFipKiqLbA1pSPICvHgNzoms9QpvwerNc6CA0ieyw== 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=viYAM9CMMrheWaoJAuhbUd7ugZDuQps4PQRsLmCMHtY=; b=nA94cp8l3oFxzK9E2bWpEW6RcXeRM84X3oNWD33RY4zOQocx3ZanDFz7hnXLoOi3o3pqrZb/bFxbqJtnbxg1NVrmQaqRT1rqX7eJeJxOODRFFfZV4l7GSUY7Xe/oQ+9Cg8IYecPCoeovqI+KQLwS+zJnykQVBPQ/KoOy6OgfiGb8BntaQHDun9jCb3YZNb+OkkF1z9BHxzwQ/vNHU43uFo9vmHNsvzfGnsF0eTWWQ+QX8TwbdOVb5uu+HuAe/tclZty9LrN3zQyJmi7FC6+AVkuLgwgofWzSTKeqi74dDEhRM/zZmw86W7ZftuF7Z1STnRGYqEyEgJ6miEQZVEJRGg== 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=viYAM9CMMrheWaoJAuhbUd7ugZDuQps4PQRsLmCMHtY=; b=c2+ypVPX8cbAnblaKUUmgL/nKP8PfZ0JEhmfhyckGaT6x9ocyQI2TgaSdR6AG1fYNxney1LRz416lut/vm4uYdk9hlMZ2nv8pw13QG3wPYqc/EQRHBKaRo7Wyqh/KuvUa77wXDl7YLX4ofpAAEyy8BgRDOJVv+wKZMGNFKPleGSWoxFxBS7C8G7yB3NGNpJAHvo8k6RPo8/Vde87Mdu9NA1hR6IQq9CBQVcYb7dKoSv01tS+JAZHQrkL1cwNKyj+0B6K3/VDNSfh2GxOR+OnaUjO6+SZPMHc+cZksFoDPBXz1tsj34bkfg1NBNehuxLZFBV3iO4Wi374p7KxklcfQA== Received: from LV8PR12MB9620.namprd12.prod.outlook.com (2603:10b6:408:2a1::19) by DM4PR12MB6591.namprd12.prod.outlook.com (2603:10b6:8:8e::13) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9654.16; Sun, 1 Mar 2026 19:22:37 +0000 Received: from LV8PR12MB9620.namprd12.prod.outlook.com ([fe80::299d:f5e0:3550:1528]) by LV8PR12MB9620.namprd12.prod.outlook.com ([fe80::299d:f5e0:3550:1528%5]) with mapi id 15.20.9654.014; Sun, 1 Mar 2026 19:22:37 +0000 Date: Sun, 1 Mar 2026 15:22:36 -0400 From: Jason Gunthorpe To: Alex Williamson Cc: David Matlack , Bjorn Helgaas , Adithya Jayachandran , Alexander Graf , Alex Mastro , Alistair Popple , Andrew Morton , Ankit Agrawal , Bjorn Helgaas , Chris Li , David Rientjes , Jacob Pan , Jonathan Corbet , Josh Hilke , Kevin Tian , kexec@lists.infradead.org, kvm@vger.kernel.org, Leon Romanovsky , Leon Romanovsky , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-mm@kvack.org, linux-pci@vger.kernel.org, Lukas Wunner , =?utf-8?Q?Micha=C5=82?= Winiarski , Mike Rapoport , Parav Pandit , Pasha Tatashin , Pranjal Shrivastava , Pratyush Yadav , Raghavendra Rao Ananta , Rodrigo Vivi , Saeed Mahameed , Samiullah Khawaja , Shuah Khan , Thomas =?utf-8?Q?Hellstr=C3=B6m?= , Tomita Moeko , Vipin Sharma , Vivek Kasireddy , William Tu , Yi Liu , Zhu Yanjun Subject: Re: [PATCH v2 03/22] PCI: Inherit bus numbers from previous kernel during Live Update Message-ID: <20260301192236.GQ5933@nvidia.com> References: <20260129212510.967611-4-dmatlack@google.com> <20260225224746.GA3714478@bhelgaas> <20260226144057.GA5933@nvidia.com> <20260227090449.2a23d06d@shazbot.org> Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260227090449.2a23d06d@shazbot.org> X-ClientProxiedBy: BL1PR13CA0314.namprd13.prod.outlook.com (2603:10b6:208:2c1::19) To LV8PR12MB9620.namprd12.prod.outlook.com (2603:10b6:408:2a1::19) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: LV8PR12MB9620:EE_|DM4PR12MB6591:EE_ X-MS-Office365-Filtering-Correlation-Id: fe80e150-6143-4081-09e5-08de77c7e5de X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|1800799024|366016|7416014|376014; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:LV8PR12MB9620.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(1800799024)(366016)(7416014)(376014);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?5ul25RFEe+YelWze2dRfuou8VUlEhs46CNba3cHVkiC0UqGwSdPUh07fIrqZ?= =?us-ascii?Q?s6SAhSDeJXTLegREOeg4jr+qsdsUpZsy4jogrEl3F8nbTZzaGPH13hSM9cQB?= =?us-ascii?Q?b8CS07wZEjJPUtxlSN8NuzO9Q7naHt8t0MIS8IYKt1RmPOchFIsup6Chbj2D?= =?us-ascii?Q?VituVbSkINt/GSWoJblCV4L9+EpNvqQaegFbWYfC6yTq5wkkoPQ60+anKqJ9?= =?us-ascii?Q?pbTyZALLRDEXB+2FCLc8nBtPsUXJWoAOnVTuhd0p8RqTnXtxLKe3RlEH5lqW?= =?us-ascii?Q?pHjM6f2jRAPbk0cHUZdAgUBzCgKX7weAhTlaugY0O4SlyT6e4eXVSYirJY0/?= =?us-ascii?Q?KBxgi4cBNoCIdZU5T5Y7NTexAfpcs7t9j2nwWu4acq/VDWEkked7dZAm+LMH?= =?us-ascii?Q?rRl8zqmkCBv5R6bsRJcDegH3qEXFO2gKPkx9u+2BbiAB5J4SNR8f4W275QRx?= =?us-ascii?Q?Uz3FirwZBhW5Vpk4xHra5ETRM1UswSRi0pToq2rhcUgYlyuczW2VsfqhLsBn?= =?us-ascii?Q?MUSCLbfESXOo+g2qMY1SmqoqsoXQ89dkJ/3TB9+LmL9hKC5RaPuzOyb2HXxW?= =?us-ascii?Q?kUG6aJW8Sw+FNAjtHUE+IYIaH4YPh5NzFmP/IUlzkuC6Mbsn7GqXcGQVLLxP?= =?us-ascii?Q?vYgQk8XHZ9IHZZEKPOfy+KPmNiQZpaj7tpK3DP0VgYCFTSzWwwaRWcT3BP98?= =?us-ascii?Q?JM5+Qs5slMDacUzuYWTyQBgy/+xb6Ux7NZtpckq7VQANL5oC62oSug8ezZc5?= =?us-ascii?Q?6vK9xGlFBbz1HhPWJm7qiEmBBcPPBqzaV66297NFFG7+Yw0uVMBlA8qJ7U7n?= =?us-ascii?Q?JPWep7IRjzNmiJaeXTGmxUuBgOTz3bgHkH/EwNqmy3+MLk8E0FC/BLbz44OV?= =?us-ascii?Q?0ZI9TpkHldmy/omFF6ximM0zdPIXKIqsnK81AVcRxBcCAhcSxLvNcHlosriH?= =?us-ascii?Q?Xwq8jlsenrHi0i7pIyz23TQdushE/6HM2GsrsglzXb2oEONBgNUsUmG3GVNW?= =?us-ascii?Q?LkxTiJKfM94QiVn5WsSHQ3hCuc8uI/PCGvog8ON8rTEmo4TAOEcVsjsdjD2t?= =?us-ascii?Q?QTYIQvb2hgWrCPCjEE/v9CuHkzZ9VD3et8QPFCoXViYYvOXe4HL4YAemstcd?= =?us-ascii?Q?tdCNnXvKxmM0QMncbeTTdV1r5o7ZVvO2InxlyYHWIKEm7566MlHuuJLSpL0j?= =?us-ascii?Q?WfUr3+VAhIUEVNiL1cqjlR2R+zgk0vUsZC8WjXCsiJ1eZDBIxBW1jDpDmbS7?= =?us-ascii?Q?ublnQEaBWSnzLDOJfobYBexkZRkBeO5tyuMigSlLMJZNByH3TwgdJnnV17cn?= =?us-ascii?Q?JLmBc4t05B9A34XEWwe9sGY/Nize9W/QqpqljhpJtiobb94foMD+r6NswmlZ?= =?us-ascii?Q?JPU018jaqnnmS35Kx6lQcwBwn0tGy2jmd/AEmRn5qFlsGgoLXJONZBZjOi4N?= =?us-ascii?Q?CeJPHBX4ensB0fRdRq2yIAhswOgF6MnMqWE50TvYdtsDBGmIgCA9EI61NhBL?= =?us-ascii?Q?t1NiMc2sdLbyFVNi5X+XS3CYl8edlnaua7iyHM4qJfJtWmfef3cG3EKolFom?= =?us-ascii?Q?Rojk7WLL4K08Adu2qYnPYUYw/acOQjVuIJRJ/L61wUQUoYqhr65v88Ta97hO?= =?us-ascii?Q?IH0++R7RnF1he+UErcoBK0Kdlo5TZYKFnSYFHgJ01GT3s/Mt69CI+OORDFju?= =?us-ascii?Q?C31ePlWLEhQUroOQly1W46bP/ZWPrAiq3tdBXXt0Gr26MUn64ARZdCb7dXVn?= =?us-ascii?Q?dZGUAEjhcw=3D=3D?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: fe80e150-6143-4081-09e5-08de77c7e5de X-MS-Exchange-CrossTenant-AuthSource: LV8PR12MB9620.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 01 Mar 2026 19:22:37.3998 (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: zGwK2QFNUuJsDoDyJi26FipSFf/XHp5Z0k4/5ZOdgJpdv5zkwN+2BaN8S8RwmPFz X-MS-Exchange-Transport-CrossTenantHeadersStamped: DM4PR12MB6591 X-Rspam-User: X-Rspamd-Server: rspam11 X-Rspamd-Queue-Id: 64D6D140007 X-Stat-Signature: s5ochzyfw6ohqoskri616k989hdwajwq X-HE-Tag: 1772392965-342449 X-HE-Meta: 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 RYMC28Eq ULYvsdKVsor6Wtr8mCb+Nxp1SsEEa/NOmIiV9F0P0nVGTIx57i1VYDjEwAe/2KqNG+kpJW1bvZpbC0DEvmFhu0BQSSY65IJDqG8YDWhZhWyaxkA3Zhu2ur9a1SdNrWSSnSfMbljO/RhULeZGNbGfme9zv652I5Bmc/I7/NH+BCNeq05vftUuh7XpT5kwpdzd0JEl6I6Ek5HvWDp8HDBAgF6Fi+x8ghZIVPYc//VtwGoshFznn8ayBEJDYwaSzbiDBDlIv941topaWFrE+196rcq4KQyIC1sGZwnX0NQjVED8X/zG/8PPaTb63TDNXolhyQpBFERAZC/8w46ut2H1uSXfTviT7qidlaix1zUitPFz67hJQH9i5MPqeQIh+9NjKlOdSEd4tWhUz07/AMjdGgRwziA== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Fri, Feb 27, 2026 at 09:04:49AM -0700, Alex Williamson wrote: > Not only fabric topology, but also routing. Yes > ACS overrides on the > command line would need to be enforced between the original and kexec > kernel such that IOMMU groups are deterministic. Thanks, That's a good point, I think as a reasonable starting point we should require live update preserved devices to have singleton iommu_groups on both sides. That is easy to check and enforce, and it doesn't matter how the administrator makes that happen. You also can't change the ACS flags while traffic is flowing because that changes the fabric routing too. This should take care to enforce that restriction as well. Jason