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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id A7A95CAC59A for ; Thu, 18 Sep 2025 08:30:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:MIME-Version: Content-Transfer-Encoding:Content-Type:References:In-Reply-To:Date:Cc:To:From :Subject:Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=/6bLOYTVutz7OZnWxHl9S+ZPChBSh4f/PGlIXbAKrEI=; b=A8CHU9gy18HUl/76fDxCjsuePX +7/hnMyniNJWT6fzVNeHXU8hou6AxZey1RD0oZakohULemb8ei/zSzy71JYwDC7fanYzjMwqsfMlA Nyxp/FH3LHpdjqumeSudoxVRre0SAuu1iwuYuaoEoMv883CrcKG6Btt2Ka0+BuIajsgHNBUtCQNSW SWQuU8ZiZ3arcc78h1zx5ksT0Ow2gJZ7vbYjvIRbBGb19OaR8Kly++BPuaTFroD7AxyW8T9lG8Bv6 g1bxRpqmvlcQFpBhsi8n2lH0jCqdxAOIJkZZ5mhw8ph0yT6sqoNL3cZg7KFNK4Is0qCp+0Pjhb0Gb U3MrZIvQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1uzA28-0000000Gheh-1JSA; Thu, 18 Sep 2025 08:30:28 +0000 Received: from s3.sipsolutions.net ([2a01:4f8:242:246e::2] helo=sipsolutions.net) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1uzA25-0000000Ghci-3Y4a for linux-um@lists.infradead.org; Thu, 18 Sep 2025 08:30:26 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sipsolutions.net; s=mail; h=MIME-Version:Content-Transfer-Encoding: Content-Type:References:In-Reply-To:Date:Cc:To:From:Subject:Message-ID:Sender :Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From:Resent-To: Resent-Cc:Resent-Message-ID; bh=/6bLOYTVutz7OZnWxHl9S+ZPChBSh4f/PGlIXbAKrEI=; t=1758184225; x=1759393825; b=aZM1oanBw0a9pHJZt2IjqJnhYcxFJYRybyjsD1b6GMZp56x qjqMbxWrHVHASUdaYt1IFcnq7y5IHxeuO+oZtFYJjHQP8h7c9YQ2gq4Ftpk2WkjsyTT7TqcLf0+EA TFYPBALnjunYB64RPBCCTsN6JfeaVzo/ybubXCVs7e/ujlDDK7CRk/WtS3JMTk3EAE40pcxg2Gjv1 3CSKIIq5it1KZVuOd3RBIANijedBI7Mgap2gBIyEBjmor9cSemd2XXK6ED2CV5LGpY5QUGamq/fqL 6gprK/j1E4h1gNa3NCPsYv9uTmwKRhyeX1ZXLzMrMaNJ0SJtf5+CgZNaLz4GC39Q==; Received: by sipsolutions.net with esmtpsa (TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim 4.98.2) (envelope-from ) id 1uzA22-0000000D9Ud-3eu7; Thu, 18 Sep 2025 10:30:23 +0200 Message-ID: Subject: Re: [PATCH RESEND v11 10/13] um: nommu: a work around for MMU dependency to PCI driver From: Johannes Berg To: Hajime Tazaki , linux-um@lists.infradead.org Cc: ricarkol@google.com, Liam.Howlett@oracle.com, linux-kernel@vger.kernel.org Date: Thu, 18 Sep 2025 10:30:22 +0200 In-Reply-To: <4a9dde10c586883d20a8201ca7d76e6d7d52eaf4.1758181109.git.thehajime@gmail.com> References: <4a9dde10c586883d20a8201ca7d76e6d7d52eaf4.1758181109.git.thehajime@gmail.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.56.2 (3.56.2-2.fc42) MIME-Version: 1.0 X-malware-bazaar: not-scanned X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250918_013025_886895_1D572CEC X-CRM114-Status: UNSURE ( 9.68 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-um@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-um" Errors-To: linux-um-bounces+linux-um=archiver.kernel.org@lists.infradead.org On Thu, 2025-09-18 at 16:39 +0900, Hajime Tazaki wrote: > The commit 8fe743b5eba0 ("PCI: Add CONFIG_MMU dependency") restricts the > PCI base driver to depend on MMU. While nommu UML _can_ implement PCI > drivers over PCI devices (e.g., virtio-pci), the current nommu UML > doesn't implement it. >=20 > But without PCI drivers kunit complains as config for kunit > (arch_uml.config) defines the dependency to PCI drivers. >=20 > This commit fixes the issue of this compile failures when building PCI > drivers with nommu UML. In particular, the fix is to undefine the > constant PCI_IOBASE to be able to bypass pci_unmap_iospace() call. This doesn't make a lot of sense to me. Why would we even want to build PCI on NOMMU-UML if PCI in general is dependent on MMU now? It's not like ARCH=3Dum with PCI and NOMMU has any value even for testing if such a configuration cannot exist in reality? johannes