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 70D665237BA; Fri, 18 Sep 2026 20:13:25 +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=1789762406; cv=none; b=k6MRFPHZM2dDCsnZ5PUJoVkUXJr8szcpCdfnSFfCvK2MUP6RGZibYdFSnroV+gFNqbG2ivuj9oTwCrIiF9sqHnoknLhENY0gF198f09zBdT7cfWgfi1w6SNKCaXwWL+J5yXgrOZftHC1Xhj9ShMPGMTG+wNfSycrYU3siHAh95Y= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789762406; c=relaxed/simple; bh=VhfaDetL1Tv74VraH8efY7aPfmn2/awy9/2560eVmv4=; h=From:Subject:To:Cc:In-Reply-To:References:Content-Type:Date: Message-Id; b=Fcy/S9uWm80+ZZtGO3EmEXNlwWYCzPe3xbxPfCNnp1PHEM62N//oV80KTeCaX6TEHW5sft4tLvFhysT2Y8B1swBTgiysK1XvFxXBS3SbUJYtCl28ygccA+8hcjTixFrG6//S+sDtEmkU+6RHTmbA+D1vNGJvHDkCXPr4q5RxOvk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=c2D0ixt7; 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="c2D0ixt7" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 987D31F000FF; Fri, 18 Sep 2026 20:13:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789762405; bh=VhfaDetL1Tv74VraH8efY7aPfmn2/awy9/2560eVmv4=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=c2D0ixt7SdY2SGgfpEcGVOwKxPpgIgHPNI6fJUCb1pwoHY5HHE8zoEEH0BZ6gZ0Sr /BLYVOhP6Rgc384qGqrFpI9J1eWiexKj9FFFE7OOVaVWGuXSfLzlcx6GiRyNGvcPKy 4pTmnFOtkzelPFI9uucqmthqaSz7i2vUFGBPExR8B3P314nvDmm0hPoV60RfbRZiq/ KVrhnvBPKXgTEYUxEALxM16oKhGb0Pvs2LZsnAlVm8xYb//HYPpgD5Wj+q4YgO0uiS RUWCaziVH6ZMq/xt+twk84Kj4GNYrMoeQB7P4Z1wYTTCOjeai8ePTMey+f6kRDkETh 7EbFfaX3KZr+g== From: sashiko-bot@kernel.org Subject: Re: [PATCH v9 06/13] PCI: liveupdate: Preserve bus numbers during Live Update Reply-To: sashiko-reviews@lists.linux.dev To: linux-doc@vger.kernel.org, "David Matlack" , linux-kernel@vger.kernel.org, linux-mm@kvack.org Cc: "David Rientjes" , kexec@lists.infradead.org, "Jacob Pan" , "Leon Romanovsky" , "Samiullah Khawaja" , "Chris Li" , "Jason Gunthorpe" , "Vipin Sharma" , "William Tu" , "Parav Pandit" , "Bjorn Helgaas" , "Alexander Graf" , "Pratyush Yadav" , "Yi Liu" , "Shuah Khan" , "Adithya Jayachandran" , "Pranjal Shrivastava" , "Alex Williamson" , "Saeed Mahameed" , "Lukas Wunner" , "Pasha Tatashin" , "Josh Hilke" , linux-pci@vger.kernel.org, "Jonathan Corbet" , "Mike Rapoport" , "Randy Dunlap" In-Reply-To: <20260918200640.887030-7-dmatlack@google.com> References: <20260918200640.887030-1-dmatlack@google.com> <20260918200640.887030-7-dmatlack@google.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Fri, 18 Sep 2026 20:13:23 +0000 Message-Id: <20260918201323.987D31F000FF@smtp.kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: > Keep the secondary and subordinate bus numbers that the previous kernel > programmed into bridges, rather than assigning new ones, if the previous > kernel preserved any device across a Live Update. Do this even on > architectures that would otherwise always assign bus numbers themselves, > e.g. when pci=3Dassign-busses is passed. >=20 > Preserved devices must be allowed to continue performing memory > transactions across a Live Update, so the kernel cannot change the > fabric topology. Changing the bus numbers of a bridge changes the > RequesterIDs of the devices below it, which would require disabling and > flushing any in-flight memory transactions first. >=20 > Apply the policy globally rather than only to the paths that contain > preserved devices. Bus numbers have to be preserved above a preserved > device anyway, since an upstream bridge cannot expand its window. A > [ ... ] > 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 > 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/20260918200640.8870= 30-1-dmatlack@google.com?part=3D6