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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id AFA98C433F5 for ; Thu, 5 May 2022 14:08:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233206AbiEEOMC (ORCPT ); Thu, 5 May 2022 10:12:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35106 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1379552AbiEEOMB (ORCPT ); Thu, 5 May 2022 10:12:01 -0400 Received: from fanzine2.igalia.com (fanzine.igalia.com [178.60.130.6]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0F41D58E7D; Thu, 5 May 2022 07:08:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=igalia.com; s=20170329; h=Content-Transfer-Encoding:Content-Type:In-Reply-To:From: References:Cc:To:Subject:MIME-Version:Date:Message-ID:Sender:Reply-To: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=8JT2x37xZIzthLtBDgRsuH3ctJdQtVKBakBAtylmM70=; b=qN2OUQgURSd4atQ9ojy4KcXFfS sWIuQHbJNPSlD2E1P1AYNseX/DMWERL/XxEbWf0Ln92hnX/LfynfNczq+DBV+OfTxTdwclMkS5O6d B5pUIzXuLcTs3oRrMsYvREgCNbi1rr5E3v9eP0PQNFUGlIsbZX30nT8Z7Fpfecrj+UabZnxoHILmC IezNI+AEM6kk7OR9ISOTKj+1sLlzN+Rsx6OlZrdElqLfko1pgXkuoNqmKFgsMlZClu9X31T7ETWdv z9SR8j82Tnr31zFYqSmR5Oiq0X3V605KjIFs9rF6sWuG7ul+kFFzulfPRxRkmmUjPVDw00dreV/2j icYj7m/A==; Received: from [179.113.53.197] (helo=[192.168.1.60]) by fanzine2.igalia.com with esmtpsa (Cipher TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_128_GCM:128) (Exim) id 1nmc9I-0005v2-8O; Thu, 05 May 2022 16:08:08 +0200 Message-ID: <53d516d2-a991-05c2-981d-640b05fc5e29@igalia.com> Date: Thu, 5 May 2022 11:07:47 -0300 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.8.1 Subject: Re: Should arm64 have a custom crash shutdown handler? Content-Language: en-US To: Vitaly Kuznetsov , Mark Rutland , "Michael Kelley (LINUX)" Cc: Marc Zyngier , Catalin Marinas , will Deacon , Russell King , Ard Biesheuvel , broonie@kernel.org, "linux-arm-kernel@lists.infradead.org" , linux-kernel , "linux-hyperv@vger.kernel.org" References: <427a8277-49f0-4317-d6c3-4a15d7070e55@igalia.com> <874k24igjf.wl-maz@kernel.org> <92645c41-96fd-2755-552f-133675721a24@igalia.com> <3bee47db-f771-b502-82a3-d6fac388aa89@igalia.com> <878rrg13zb.fsf@redhat.com> From: "Guilherme G. Piccoli" In-Reply-To: <878rrg13zb.fsf@redhat.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-hyperv@vger.kernel.org On 05/05/2022 10:52, Vitaly Kuznetsov wrote: > [...] > For Hyper-V, the situation is similar: hv_crash_handler() intitiates > VMbus unload on the crashing CPU only, there's no mechanism to do > 'global' unload so other CPUs will likely not be able to connect Vmbus > devices in kdump kernel but this should not be necessary. > > There's a crash_kexec_post_notifiers mechanism which can be used instead > but it's disabled by default so using machine_ops.crash_shutdown is > better. > Thanks a bunch Vitaly, for the clarification! Just as a heads-up: there's been a panic notifiers refactor proposed [0] in which some notifiers will run before kdump by default, not requiring "crash_kexec_post_notifiers" (which BTW is *unfortunately* hardcoded as 'Y' for hyper-v, since a11589563e96). Cheers, Guilherme [0] https://lore.kernel.org/lkml/20220427224924.592546-1-gpiccoli@igalia.com/