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=-2.3 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 59951C352AA for ; Wed, 2 Oct 2019 14:59:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2DC1121783 for ; Wed, 2 Oct 2019 14:59:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727718AbfJBO7L (ORCPT ); Wed, 2 Oct 2019 10:59:11 -0400 Received: from mx2.suse.de ([195.135.220.15]:45962 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726070AbfJBO7L (ORCPT ); Wed, 2 Oct 2019 10:59:11 -0400 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 C15BCABD3; Wed, 2 Oct 2019 14:59:09 +0000 (UTC) Subject: Re: [Xen-devel] [PATCH] x86/xen: Return from panic notifier To: Boris Ostrovsky Cc: james@dingwall.me.uk, xen-devel@lists.xenproject.org, Juergen Gross , linux-kernel@vger.kernel.org References: <20191001151633.1659-1-boris.ostrovsky@oracle.com> <9b3f955c-ad76-601f-2b58-fa9dc4608c72@suse.com> <924f41b2-7779-9c56-9b71-56523756ecdc@oracle.com> <5650904d-b616-5ee7-216a-a0ac28d7426d@suse.com> <9d6b6b00-a3b1-95b4-7633-597c0094ab90@oracle.com> From: Jan Beulich Message-ID: <63155d02-1082-3f26-6c2f-76aa3b753302@suse.com> Date: Wed, 2 Oct 2019 16:59:16 +0200 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.9.0 MIME-Version: 1.0 In-Reply-To: <9d6b6b00-a3b1-95b4-7633-597c0094ab90@oracle.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 02.10.2019 16:14, Boris Ostrovsky wrote: > On 10/2/19 9:42 AM, Jan Beulich wrote: >> >> I can only guess that the thinking probably was that e.g. external >> dumping (by the tool stack) would be more reliable (including but >> not limited to this meaning less change of state from when the >> original crash reason was detected) than having the domain dump >> itself. > > > We could register an external dumper (controlled by a boot option > perhaps, off by default) that will call directly into hypervisor with > SHUTDOWN_crash. That will guarantee that we will complete the notifier > chain without relying on priorities. (Of course this still won't address > a possible new feature in panic() that might be called post-dumping) > > If you think it's worth doing this can be easily added. Well, I think this is the better option than potentially pingponging between the two extremes, because one wants it the way it currently is and another wants it the way this patch changes things to. Jan