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=-2.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,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 C253CC43441 for ; Mon, 26 Nov 2018 18:05:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8A80C20672 for ; Mon, 26 Nov 2018 18:05:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=alien8.de header.i=@alien8.de header.b="lON9v+LK" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8A80C20672 Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=alien8.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727195AbeK0E74 (ORCPT ); Mon, 26 Nov 2018 23:59:56 -0500 Received: from mail.skyhub.de ([5.9.137.197]:37934 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726260AbeK0E74 (ORCPT ); Mon, 26 Nov 2018 23:59:56 -0500 Received: from zn.tnic (p200300EC2BDEFE00DCA0409AA15535E1.dip0.t-ipconnect.de [IPv6:2003:ec:2bde:fe00:dca0:409a:a155:35e1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.skyhub.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id F0D1F1EC0322; Mon, 26 Nov 2018 19:05:01 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1543255502; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:in-reply-to:in-reply-to: references:references; bh=ChvP+UjJ7prXGEQ3jKDqJr2y9tMZ8xxMzhAsQHE/AzQ=; b=lON9v+LKRr14FAl7ApzmzkGLHJFg/Bp1B+/K7WuJVpVSdH36rMceiqaTPLHCSRN0Dzwy+7 akztekR99vEZ58HadsS7Qc1FydMIJVHNieZ2n94hvpyBQxlz7iU3m4qmR4if/otRnJ6ycn Ilz8lYkSmsLQ3rskFTPHDOlc+E+CNdc= Date: Mon, 26 Nov 2018 19:04:55 +0100 From: Borislav Petkov To: Dave Hansen Cc: Lianbo Jiang , linux-kernel@vger.kernel.org, kexec@lists.infradead.org, x86@kernel.org, linux-ia64@vger.kernel.org, linux-efi@vger.kernel.org, tglx@linutronix.de, mingo@redhat.com, akpm@linux-foundation.org, dave.hansen@linux.intel.com, luto@kernel.org, peterz@infradead.org, ard.biesheuvel@linaro.org, tony.luck@intel.com, fenghua.yu@intel.com, dyoung@redhat.com, bhe@redhat.com Subject: Re: [PATCH 0/2 RESEND v7] add reserved e820 ranges to the kdump kernel e820 table Message-ID: <20181126180455.GI4843@zn.tnic> References: <20181124051223.19994-1-lijiang@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Nov 26, 2018 at 09:44:46AM -0800, Dave Hansen wrote: > On 11/23/18 9:12 PM, Lianbo Jiang wrote: > > These patches add the new I/O resource descriptor 'IORES_DESC_RESERVED' > > for the iomem resources search interfaces, and in order to make it still > > work after the new descriptor is added, these codes originally related > > to 'IORES_DESC_NONE' have been updated. > > I'm having a really hard time figuring out what problem these patches solve. > > What end-user visible behavior does this set change? Yeah, that was a long process of digging out the "why". I'd recommend reading the previous threads and, more specifically: https://lkml.kernel.org/r/CABhMZUUscS3jUZUSM5Y6EYJK6weo7Mjj5-EAKGvbw0qEe%2B38zw@mail.gmail.com in short: we need to export e820 reserved ranges to the second kernel so that it can talk to PCI devices properly. (And I'm wondering how it did work until now...) -- Regards/Gruss, Boris. Good mailing practices for 400: avoid top-posting and trim the reply.