From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 1E8F541DE0C for ; Tue, 28 Jul 2026 22:19:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785277194; cv=none; b=KNrdn74kCUvkm+U+9LvL8rS1gVK0mQe1KpFsJ1WP2OUpynz5iUNJ4aNk07QO/XWVWqRzWeccO1RIbfIPkKver6/Q45gSZCSQJS5Dqa4+gU34qtav089/dSATFLZcgvcneV7vT2/b/C4mbxlKqo9FUDfvWnnd+8Y7IyNwPw+28FU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785277194; c=relaxed/simple; bh=efOlloiqOSRHfuRbJ/yOvxHhx0zBMUDvoYHHpLqzTNo=; h=From:Subject:To:Cc:In-Reply-To:References:Content-Type:Date: Message-Id; b=lrS8i/9h6+jzkcI9+w9EVXc/7R/nPMCvWIQuDHI3Wi8rxPrvpEPidIIeQ9rFjr+OWPsnMtpxwsyNyv2sSPa+nkaAYpNww8+a/WeoLhqNeXo/GPY+eSypr5ebMYyrl7zi6Lnm5NyJ5h7PnIRMC6ESFNh6uWAne4Kw+kns3LpsEFs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Fe9EACG4; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Fe9EACG4" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6F9281F000E9; Tue, 28 Jul 2026 22:19:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1785277192; bh=efOlloiqOSRHfuRbJ/yOvxHhx0zBMUDvoYHHpLqzTNo=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=Fe9EACG4MoDYMnzajcvvrYbXLngzhLyoY38MdV2evAjnUS9FKJE1nUhulL1FUJ/pX 7L3pYC/RoYUYp5RMghsu51pcpCpfQ+4IM3ORwJupk6jJz+l8Zr88UFaDvIWy+abSOb g/tMD6OpGM81Y5rDBpfmI/UYnoUO16Kz60tPatTS266Xx8GCcgxOKqroXSL8BTnluP uHxt7hyHvYs5FBdNW85sZSiJyvMxH7oPuCdRfoLmvtmyUbmVRwcns5ryzqRpB91IwQ PJqfoKwxGtVYOqxafSxCUr7Rgsk8sxHInrdQCNvFDxoWuMlV83i/6bvzPGCEcVboeH RT+BG3GbRi6BA== From: sashiko-bot@kernel.org Subject: Re: [PATCH v8 05/12] PCI: liveupdate: Preserve bus numbers during Live Update Reply-To: sashiko-reviews@lists.linux.dev To: "David Matlack" Cc: linux-pci@vger.kernel.org In-Reply-To: <20260728221007.2098560-6-dmatlack@google.com> References: <20260728221007.2098560-1-dmatlack@google.com> <20260728221007.2098560-6-dmatlack@google.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Tue, 28 Jul 2026 22:19:52 +0000 Message-Id: <20260728221952.6F9281F000E9@smtp.kernel.org> Precedence: bulk X-Mailing-List: linux-pci@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: > During a Live Update, preserved devices must be allowed to continue > performing memory transactions so the kernel cannot change the fabric > topology, including bus numbers, since that would require disabling and > flushing any memory transactions first. >=20 > To keep bus numbers constant, always preserve the secondary and > subordinate bus numbers assigned to bridges during scanning, instead of > assigning new ones, if any PCI devices were preserved. Note that the > kernel preserves bus numbers even on bridges without any downstream > endpoints that were preserved. This avoids accidentally assigning a > bridge a new window that overlaps with a preserved device that is > downstream of a different bridge. >=20 > If a bridge is scanned with a broken topology or has no bus numbers set > during a Live Update, refuse to assign it new bus numbers and refuse to > enumerate devices below it until the Live Update is finished. This is a > safety measure to prevent topology conflicts. >=20 > Require that CONFIG_CARDBUS is not enabled to enable > CONFIG_PCI_LIVEUPDATE since preserving bus numbers on PCI-to-CardBus > bridges requires additional work but is not a priority at the moment. >=20 > Reviewed-by: Pranjal Shrivastava > Reviewed-by: Samiullah Khawaja > Reviewed-by: Pasha Tatashin > Signed-off-by: David Matlack Sashiko has reviewed this patch and found no issues. It looks great! --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20260728221007.2098= 560-1-dmatlack@google.com?part=3D5