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 6026C3C0613 for ; Fri, 10 Jul 2026 21:32:51 +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=1783719173; cv=none; b=EPp8DMBwPs7Zd3fBVYtMLFfJDLJmAzF+7kcRkYC4eL+U6xD3cxLNqlzoEJBXHiwguseRo+ccuK6OquLMHdy/PfHQaS9OOOGr4zalpg5xjfjOSF1+o2nTpL2xEn24mCD8n/BalKW+LpQVmiXSBkAdZgaLY4ioL7lc09wTnl+vfpA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783719173; c=relaxed/simple; bh=7QkVxz/1UrwJ5lJjtLvVAkER8lnDsP0VGdXx1Phg29I=; h=From:Subject:To:Cc:In-Reply-To:References:Content-Type:Date: Message-Id; b=NgyGZLx85RIfDUYQe4vvexVa3nY5G5Bhph0/gkEAaE1mFRRZTgiWZsBV6tqSDilaEpJMFJlkO6Rw9MYw2gupMeici/n+qhyI7YpVvw6cT7kbyemJNIljfhXZuzLQDoDVZcoouvlDQ5a5lR9VOjj5h3HhqG0Ag7O5U3OUfUlx+es= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=g1DoJVLc; 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="g1DoJVLc" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3C6751F000E9; Fri, 10 Jul 2026 21:32:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1783719170; bh=7QkVxz/1UrwJ5lJjtLvVAkER8lnDsP0VGdXx1Phg29I=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=g1DoJVLc4bpXkBU9O8Zi/5FDaFZ2T3fO3NYqePn0vTdw5yBGdPsSBn9LcrKXHlM6N osrPePPq0wIsN6LfYl7I3RGiyqGZ0EZl8Us31gdh/QpQ8rs7PD+bF5K7x8hdowRJ9t YbYz0O5OQFBx6byTlKez8yTAdmXOBK891tvD/x6a0f4xyO0XIzjEbYPlVGQrieucuf bJ5eJpIF/R3o5mBM19D++oj2WWy0sCu8l3xMvkK4BDdapOSIJWQQ+V6PQZBVADgLyl Rhs/ODRQm3cwxVyfVRmZXiCLw4+9n2hzrz2J27qJ1gNundBTYKAGLtSQZ3JcyhlVTi CzPJhyjjbrOfQ== From: sashiko-bot@kernel.org Subject: Re: [PATCH v7 05/12] PCI: liveupdate: Keep bus numbers constant during Live Update Reply-To: sashiko-reviews@lists.linux.dev To: "David Matlack" Cc: linux-pci@vger.kernel.org In-Reply-To: <20260710212616.1351130-6-dmatlack@google.com> References: <20260710212616.1351130-1-dmatlack@google.com> <20260710212616.1351130-6-dmatlack@google.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Fri, 10 Jul 2026 21:32:49 +0000 Message-Id: <20260710213250.3C6751F000E9@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 inherit the secondary and > subordinate bus numbers assigned to bridges during scanning, instead of > assigning new ones, if any PCI devices are being preserved. Note that > the kernel inherits 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 inheriting 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 > 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/20260710212616.1351= 130-1-dmatlack@google.com?part=3D5