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=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham 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 6BFFBC43381 for ; Thu, 28 Feb 2019 14:17:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 38D00214D8 for ; Thu, 28 Feb 2019 14:17:11 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="eIIytkDc" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732506AbfB1ORJ (ORCPT ); Thu, 28 Feb 2019 09:17:09 -0500 Received: from bombadil.infradead.org ([198.137.202.133]:39954 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728092AbfB1ORJ (ORCPT ); Thu, 28 Feb 2019 09:17:09 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding: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=TLQHLE9rRd13OypqLRwJDvPJOba+66nl6LBftU+TYok=; b=eIIytkDcPIojBLcO7XkyjwDYP kNqHAmHb+9JnwHrtHkc/kal8f+HCFzDRZ7zgkIWCrt045p6U+dbv9sl4AqMpomzVcbMAPok3Zt5MC 5c5rLCA0qRPRCWXoRWIqM7sMU74EIGTr/pga/DZ9KhTa6rYth3cTCsAn9Yq5Rco1wnNyL8gr73WEv l44LKnzFCa01CZ7M7EK6Y3CjDmcfd+TRXcws88dIfhaqSoqOnxZ+UYjo1wcYFI1QzG9HnzqWOllU+ VdZ8IOqlW8TEUGLosvGIjBZV6HPU9kXFe9Y/kulZuNtm15s5vGfBw6lvJhuLtxNWaZB1Hg/OojW2N Is9deVdzA==; Received: from hch by bombadil.infradead.org with local (Exim 4.90_1 #2 (Red Hat Linux)) id 1gzMUa-0006Lp-0K; Thu, 28 Feb 2019 14:16:56 +0000 Date: Thu, 28 Feb 2019 06:16:55 -0800 From: Christoph Hellwig To: Austin.Bolen@dell.com Cc: Alex_Gagniuc@Dellteam.com, torvalds@linux-foundation.org, keith.busch@intel.com, sagi@grimberg.me, linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org, axboe@fb.com, mr.nuke.me@gmail.com, hch@lst.de, jonathan.derrick@intel.com Subject: Re: [PATCH] nvme-pci: Prevent mmio reads if pci channel offline Message-ID: <20190228141655.GA18319@infradead.org> References: <2b7d8f45d11c47e69f56ad1bc3324dd1@ausx13mps321.AMER.DELL.COM> <20190225155501.GI10237@localhost.localdomain> <940d608e1a044a54abcb9d65923951f3@ausx13mps317.AMER.DELL.COM> <443262761d0e41fbb46a46dab28759c2@AUSX13MPC131.AMER.DELL.COM> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <443262761d0e41fbb46a46dab28759c2@AUSX13MPC131.AMER.DELL.COM> User-Agent: Mutt/1.9.2 (2017-12-15) X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Feb 27, 2019 at 08:04:35PM +0000, Austin.Bolen@dell.com wrote: > Confirmed this issue does not apply to the referenced Dell servers so I > don't not have a stake in how this should be handled for those systems. > It may be they just don't support surprise removal. I know in our case > all the Linux distributions we qualify (RHEL, SLES, Ubuntu Server) have > told us they do not support surprise removal. So I'm guessing that any > issues found with surprise removal could potentially fall under the > category of "unsupported". > > Still though, the larger issue of recovering from other types of PCIe > errors that are not due to device removal is still important. I would > expect many system from many platform makers to not be able to recover > PCIe errors in general and hopefully the new DPC CER model will help > address this and provide added protection for cases like above as well. FYI, a related issue I saw about a year two ago with Dell servers was with a dual ported NVMe add-in (non U.2) card, is that once you did a subsystem reset, which would cause both controller to retrain the link you'd run into Firmware First error handling issue that would instantly crash the system. I don't really have the hardware anymore, but the end result was that I think the affected product ended up shipping with subsystem resets only enabled for the U.2 form factor.