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 X-Spam-Level: X-Spam-Status: No, score=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 49EE4C43603 for ; Mon, 9 Dec 2019 11:55:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 211132077B for ; Mon, 9 Dec 2019 11:55:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727648AbfLILzE (ORCPT ); Mon, 9 Dec 2019 06:55:04 -0500 Received: from mx2.suse.de ([195.135.220.15]:45070 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727328AbfLILzD (ORCPT ); Mon, 9 Dec 2019 06:55:03 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 1914EAEE9; Mon, 9 Dec 2019 11:55:02 +0000 (UTC) Subject: Re: [Xen-devel] [PATCH 2/4] xenbus: limit when state is forced to closed To: =?UTF-8?Q?Roger_Pau_Monn=c3=a9?= , Paul Durrant Cc: linux-kernel@vger.kernel.org, xen-devel@lists.xenproject.org, Stefano Stabellini , Boris Ostrovsky References: <20191205140123.3817-1-pdurrant@amazon.com> <20191205140123.3817-3-pdurrant@amazon.com> <20191209113926.GS980@Air-de-Roger> From: =?UTF-8?B?SsO8cmdlbiBHcm/Dnw==?= Message-ID: Date: Mon, 9 Dec 2019 12:55:01 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.2.1 MIME-Version: 1.0 In-Reply-To: <20191209113926.GS980@Air-de-Roger> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 09.12.19 12:39, Roger Pau Monné wrote: > On Thu, Dec 05, 2019 at 02:01:21PM +0000, Paul Durrant wrote: >> Only force state to closed in the case when the toolstack may need to >> clean up. This can be detected by checking whether the state in xenstore >> has been set to closing prior to device removal. > > I'm not sure I see the point of this, I would expect that a failure to > probe or the removal of the device would leave the xenbus state as > closed, which is consistent with the actual driver state. > > Can you explain what's the benefit of leaving a device without a > driver in such unknown state? And more concerning: did you check that no frontend/backend is relying on the closed state to be visible without closing having been set before? Juergen