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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 96AC3C433F5 for ; Fri, 1 Oct 2021 16:45:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6A1C761A08 for ; Fri, 1 Oct 2021 16:45:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232134AbhJAQrS (ORCPT ); Fri, 1 Oct 2021 12:47:18 -0400 Received: from netrider.rowland.org ([192.131.102.5]:54681 "HELO netrider.rowland.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S232114AbhJAQrS (ORCPT ); Fri, 1 Oct 2021 12:47:18 -0400 Received: (qmail 508736 invoked by uid 1000); 1 Oct 2021 12:45:33 -0400 Date: Fri, 1 Oct 2021 12:45:33 -0400 From: Alan Stern To: Dan Williams Cc: Greg Kroah-Hartman , "Kuppuswamy, Sathyanarayanan" , "Michael S. Tsirkin" , Borislav Petkov , X86 ML , Bjorn Helgaas , Thomas Gleixner , Ingo Molnar , Andreas Noever , Michael Jamet , Yehezkel Bernat , "Rafael J . Wysocki" , Mika Westerberg , Jonathan Corbet , Jason Wang , Andi Kleen , Kuppuswamy Sathyanarayanan , Linux Kernel Mailing List , Linux PCI , USB list , virtualization@lists.linux-foundation.org Subject: Re: [PATCH v2 4/6] virtio: Initialize authorized attribute for confidential guest Message-ID: <20211001164533.GC505557@rowland.harvard.edu> References: <20210930010511.3387967-1-sathyanarayanan.kuppuswamy@linux.intel.com> <20210930010511.3387967-5-sathyanarayanan.kuppuswamy@linux.intel.com> <20210930065953-mutt-send-email-mst@kernel.org> <6d1e2701-5095-d110-3b0a-2697abd0c489@linux.intel.com> <1cfdce51-6bb4-f7af-a86b-5854b6737253@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Fri, Oct 01, 2021 at 09:13:54AM -0700, Dan Williams wrote: > Bear with me, and perhaps it's a lack of imagination on my part, but I > don't see how to get to a globally generic "authorized" sysfs ABI > given that USB and Thunderbolt want to do bus specific actions on > authorization toggle events. Certainly a default generic authorized > attribute can be defined for all the other buses that don't have > legacy here, but Thunderbolt will still require support for '2' as an > authorized value, and USB will still want to base probe decisions on > the authorization state of both the usb_device and the usb_interface. The USB part isn't really accurate (I can't speak for Thunderbolt). When a usb_device is deauthorized, the device will be unconfigured, deleting all its interfaces and removing the need for any probe decisions about them. In other words, the probe decision for a usb_device or usb_interface depends only on the device's/interface's own authorization state. True, the interface binding code does contain a test of the device's authorization setting. That test is redundant and can be removed. The actions that USB wants to take on authorization toggle events for usb_devices are: for authorize, select and install a configuration; for deauthorize, unconfigure the device. Each of these could be handled simply enough just by binding/unbinding the device. (There is some special code for handling wireless USB devices, but wireless USB is now defunct.) Alan Stern