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=-6.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 9EB8EC433E1 for ; Thu, 20 Aug 2020 13:48:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 793DF2076E for ; Thu, 20 Aug 2020 13:48:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597931319; bh=FimYMkYiuCDAGzXaOaFsHcjupgUWLh69vV0SwtvI274=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=zGcIuoY9MZ06RUqUKxG9rFE2wf7+AZ9CVMaGnvHb0l5mrlPQoE6lXU3OI7gd0VQDs BZtZJFOmoHA2/XzNzTfFjUXmeMR7wFgTcnduDzbAJkU00/nZfQBxCyEh9n2/lIV4RJ ZLQPw4ev4v0B9wg415WBJMx//mPNmu2iJfkmt3UQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728403AbgHTNsi (ORCPT ); Thu, 20 Aug 2020 09:48:38 -0400 Received: from mail.kernel.org ([198.145.29.99]:55218 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729802AbgHTNsf (ORCPT ); Thu, 20 Aug 2020 09:48:35 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 547CF2076E; Thu, 20 Aug 2020 13:48:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597931315; bh=FimYMkYiuCDAGzXaOaFsHcjupgUWLh69vV0SwtvI274=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=ncOdIJhtiTxsJ9QTmxsqNlnXldF8i7NK/RsboPTTA31D0Jjg6CngNl3P/2TehtER2 Fv2QvLF9/6tVbcAVaNVOYvDmvyl2ZrZ1ZqMG/nZftl1DETQ+18PWb1ncuGRzV/aPml NU6S9v22GUrQ4Gu5c7bmSwTLJXmYGSbugShuEsuA= Date: Thu, 20 Aug 2020 15:48:55 +0200 From: Greg Kroah-Hartman To: Sasha Levin Cc: Michael Kelley , "linux-kernel@vger.kernel.org" , "stable@vger.kernel.org" , Wei Hu , Lorenzo Pieralisi Subject: Re: [PATCH 5.8 164/232] PCI: hv: Fix a timing issue which causes kdump to fail occasionally Message-ID: <20200820134855.GB1533625@kroah.com> References: <20200820091612.692383444@linuxfoundation.org> <20200820091620.754492308@linuxfoundation.org> <20200820132924.GA8670@sasha-vm> <20200820134823.GA1533625@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200820134823.GA1533625@kroah.com> Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On Thu, Aug 20, 2020 at 03:48:23PM +0200, Greg Kroah-Hartman wrote: > On Thu, Aug 20, 2020 at 09:29:24AM -0400, Sasha Levin wrote: > > On Thu, Aug 20, 2020 at 01:00:51PM +0000, Michael Kelley wrote: > > > From: Greg Kroah-Hartman Sent: Thursday, August 20, 2020 2:20 AM > > > > > > > > From: Wei Hu > > > > > > > > [ Upstream commit d6af2ed29c7c1c311b96dac989dcb991e90ee195 ] > > > > > > > > Kdump could fail sometime on Hyper-V guest because the retry in > > > > hv_pci_enter_d0() releases child device structures in hv_pci_bus_exit(). > > > > > > > > Although there is a second asynchronous device relations message sending > > > > from the host, if this message arrives to the guest after > > > > hv_send_resource_allocated() is called, the retry would fail. > > > > > > > > Fix the problem by moving retry to hv_pci_probe() and start the retry > > > > from hv_pci_query_relations() call. This will cause a device relations > > > > message to arrive to the guest synchronously; the guest would then be > > > > able to rebuild the child device structures before calling > > > > hv_send_resource_allocated(). > > > > > > > > Link: > > > > https://lore.kernel.org/linux-hyperv/20200727071731.18516-1-weh@microsoft.com/ > > > > Fixes: c81992e7f4aa ("PCI: hv: Retry PCI bus D0 entry on invalid device state") > > > > Signed-off-by: Wei Hu > > > > [lorenzo.pieralisi@arm.com: fixed a comment and commit log] > > > > Signed-off-by: Lorenzo Pieralisi > > > > Reviewed-by: Michael Kelley > > > > Signed-off-by: Sasha Levin > > > > --- > > > > drivers/pci/controller/pci-hyperv.c | 71 +++++++++++++++-------------- > > > > 1 file changed, 37 insertions(+), 34 deletions(-) > > > > > > > > > > This patch came through three days ago, and I indicated then that we don't want > > > it backported to 5.8 and earlier. > > > > Uh, I re-added it by mistake, sorry. > > Ok, let me go drop it... Oops, you already did :)