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 D68D1FD45F1 for ; Wed, 25 Feb 2026 23:20:20 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 2FB026B0089; Wed, 25 Feb 2026 18:20:20 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 2B1876B008A; Wed, 25 Feb 2026 18:20:20 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 1CB316B008C; Wed, 25 Feb 2026 18:20:20 -0500 (EST) 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 0A1106B0089 for ; Wed, 25 Feb 2026 18:20:20 -0500 (EST) Received: from smtpin30.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay05.hostedemail.com (Postfix) with ESMTP id BD5685A2A5 for ; Wed, 25 Feb 2026 23:20:19 +0000 (UTC) X-FDA: 84484549758.30.5D19C8C Received: from mail-pf1-f175.google.com (mail-pf1-f175.google.com [209.85.210.175]) by imf04.hostedemail.com (Postfix) with ESMTP id E119340010 for ; Wed, 25 Feb 2026 23:20:17 +0000 (UTC) Authentication-Results: imf04.hostedemail.com; dkim=pass header.d=google.com header.s=20230601 header.b=OVNuV2aY; dmarc=pass (policy=reject) header.from=google.com; spf=pass (imf04.hostedemail.com: domain of dmatlack@google.com designates 209.85.210.175 as permitted sender) smtp.mailfrom=dmatlack@google.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1772061618; a=rsa-sha256; cv=none; b=NUI1zW6HsJW1H20Jw45hHkNTLP4UomplWvvHFP7DZ16veCqOjZ5AF79gO8FGnYXZsAnXol BaeJg0gv880RNTvtVZgVOgxf16L0hjGENpEvjEU6ui6RjorF3V6I7EFFlrRE6Rl5w8TGAO 3TUxS4xn+B/dQ8HEeTHS35v3xDa5PjM= ARC-Authentication-Results: i=1; imf04.hostedemail.com; dkim=pass header.d=google.com header.s=20230601 header.b=OVNuV2aY; dmarc=pass (policy=reject) header.from=google.com; spf=pass (imf04.hostedemail.com: domain of dmatlack@google.com designates 209.85.210.175 as permitted sender) smtp.mailfrom=dmatlack@google.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1772061618; 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=aEWfuL1WgCP/eH/o3qO74sPfk+Pg3+xsCKw2mq2gLYE=; b=7sgPFh7sHbfcgoUXEIdAOFq7vvTOgrx5CsQxD2qQ445zjLCI5kDhtruSldX7MkarGVcCXF twN54/typNj/RfZP0S37mR+jNVulA4EVbr5VBLB9IRjtwj5OjihPcnOrpEcfVve9n1t2ZF TM8+xRbqvEe4/MzB5l7FYGynPB36LDI= Received: by mail-pf1-f175.google.com with SMTP id d2e1a72fcca58-8272a56b91cso284636b3a.1 for ; Wed, 25 Feb 2026 15:20:17 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1772061617; x=1772666417; darn=kvack.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=aEWfuL1WgCP/eH/o3qO74sPfk+Pg3+xsCKw2mq2gLYE=; b=OVNuV2aYncrcQzNT+5fz2f0w3ohXq5mdIA5KEFfwE6tcP8Y8ltsaw0C6Z1vWOKtgrf vUOScO2K1uNzRMTsmdiyZjb66GYpFq99Cee6wdiDnxlZfeGCbYMQQnA4GFfVQhFOAaSU f0pxkEwMtlvRPokZU6yV1UME48Y6VoSt90AgitqSbF75qOL/r5VTQnl9elUtWOzZ7fEd ttdMLYaejTrhfvduKPYi0lZKBK7oyrPu+UWZZbT5Kpc5sfrYk+OP2KP11SzB2UF2uS3a MzZEDPtUEGrX1FHpVZfSgMDDIY4fq51XdjZz+FuYuQ2RMFDFvUqRhQhGDdX9ctxIxI+V jA6w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1772061617; x=1772666417; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-gg:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=aEWfuL1WgCP/eH/o3qO74sPfk+Pg3+xsCKw2mq2gLYE=; b=e/TgsulUTpdfKdCEvkpiH1inKgZowmCwQaHH9kMLMgOOyZBwgzSgGaNEPLoFtIt2Pd gXdqaGtw0ngMzohhoxyiVvO7GKDMJrhxZ4EfJ3T99OsKUc4C9G4pGV5xJ8aNVmoh8/Br YRc9QXJIJXyT0QmR78OpU71fFzA9gwdNWx5WC2qGhEn/Ei4SejQ7/NDdC8LYptg6rcCX wYIt5Y550LbNknhU+uxhMlCWH3kfdlUMsDHDG0lRwYGpukJaoguGmQwwnhyOVFxUHTpj fOgILM1ww4ftT845T1i825z2lPt8hkqqvh9XUWpc6rJOnoTKGK/8OaOVNmitiCFmKYK1 DCnw== X-Forwarded-Encrypted: i=1; AJvYcCX1wCxPl86SQwu/WXV2/lOotWEU6W8Ob6mG9x4/ym4qTW7yoe8qYO8aDxPgcnW3Ns2d7q/Le4zJHg==@kvack.org X-Gm-Message-State: AOJu0Yy8gLMh1s9w6AkYGQ64nk8zbobx6LOiEoUQ7jVwE4vE0+TxGN8h nrGM+V9gtLzb2+sqLteZmqhKo/KNk3vMt6CjElLQzPJpsVSG4iihUDPI+6ocmxqBMw== X-Gm-Gg: ATEYQzxyDF+6x6An8Ls2mYgUdx3BJDbN1jVQGhvkIm6PKfbCfSySHHbZOgGnpSfne6a b+qQUAwf46snPymruYYLG3KP/RdfMd91UNweGv9HM4UFiGT9fhLORjWaRni52FYFepUZ29ELMAG 8WAeq9jQJNx5FVJuzO0wv3/vppjOn+ARpxy1T0xkFRgub2PjTdcVlRExj2FGS4koRI5pTXNo1vV iXOBu5D2nt4Q/8UwTYpgD6GP1rWKFV1BOpZbhTlAQ2PQK9EVU9xGfbfrnms721rgYNgHxpjV+TA /nPU9keH1b2JQsB5SZD+NxnKXCBvZ3Uq1694SX1GVEOll50BYVVTLTxaXoIodwLGWH7lQ6SpGFc 4R/dHS4KMmQYQys/NuyYDzrx0maWKY4GKkvlS/vxXBwOcJ4yMNC0yun10GRrHsh2uXEJ/WOUicp ccfqSJSG9uQNCZxJWu44d70eY0nP0mmA6y9cx2n4WBtvPX33ENvUZZ1nEnA34BEw== X-Received: by 2002:a05:6a00:18a7:b0:81f:852b:a91c with SMTP id d2e1a72fcca58-8273390dcc3mr1547131b3a.64.1772061616376; Wed, 25 Feb 2026 15:20:16 -0800 (PST) Received: from google.com (239.23.105.34.bc.googleusercontent.com. [34.105.23.239]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-82739ff37f1sm347240b3a.40.2026.02.25.15.20.13 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 25 Feb 2026 15:20:14 -0800 (PST) Date: Wed, 25 Feb 2026 23:20:10 +0000 From: David Matlack To: Bjorn Helgaas Cc: Alex Williamson , Adithya Jayachandran , Alexander Graf , Alex Mastro , Alistair Popple , Andrew Morton , Ankit Agrawal , Bjorn Helgaas , Chris Li , David Rientjes , Jacob Pan , Jason Gunthorpe , Jason Gunthorpe , 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 =?iso-8859-1?Q?Hellstr=F6m?= , 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: References: <20260129212510.967611-4-dmatlack@google.com> <20260225224746.GA3714478@bhelgaas> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260225224746.GA3714478@bhelgaas> X-Rspam-User: X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: E119340010 X-Stat-Signature: zccj7b61ow1fcsfocwpcbhxab5dy7jpa X-HE-Tag: 1772061617-873403 X-HE-Meta: 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 hkuysi6Q W7669ZjcJG+hwBAXQgy8hWxo3MdZw6H/gY/ZASSAH0zTyouO7k8ziSKMCNJ2Iq1l6SDNzG5tNvePtkWMq/xvalPlyql+q8053B0iKTWUQKhcJQqupmqafJskpfiBOt2NX7trZPgjUa7zKiKyBareq2FuI81ulx4HNTfJGCu0dzu87Y5Hc8w7qyV5xrR1iq44+Evb0qarbcmqH5P6R2oPm5ZFYdNbjs7nTs3Md602TP1g7XBOhIoI3Hh3EacppxVBCVlyKi5uTF+4/NKu/D2FeM8qIsPmME74qZySDblQnn70MvN0w6FVBoUrKWkhvJvb8h4cRd+euyO0EkCyb3pLnijBMOVbPa/DvsNeUv9AnnrY09PA= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 2026-02-25 04:47 PM, Bjorn Helgaas wrote: > On Thu, Jan 29, 2026 at 09:24:50PM +0000, David Matlack wrote: > > Inherit bus numbers from the previous kernel during a Live Update when > > one or more PCI devices are being preserved. This is necessary so that > > preserved devices can DMA through the IOMMU during a Live Update > > (changing bus numbers would break IOMMU translation). > > I think changing bus numbers would break DMA regardless of whether an > IOMMU is involved. Completions carrying the data for DMA reads are > routed back to the Requester ID of the read. Ahh, makes sense. I'll clarify the commit message in the next version.