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 F116CC43381 for ; Mon, 25 Mar 2019 12:01:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B2B2520850 for ; Mon, 25 Mar 2019 12:01:49 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=alien8.de header.i=@alien8.de header.b="QPLjSQUH" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730996AbfCYMBs (ORCPT ); Mon, 25 Mar 2019 08:01:48 -0400 Received: from mail.skyhub.de ([5.9.137.197]:43918 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730837AbfCYMBs (ORCPT ); Mon, 25 Mar 2019 08:01:48 -0400 Received: from zn.tnic (p200300EC2F098000329C23FFFEA6A903.dip0.t-ipconnect.de [IPv6:2003:ec:2f09:8000:329c:23ff:fea6:a903]) (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 2A9A71EC0AB1; Mon, 25 Mar 2019 13:01:46 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1553515306; 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=Jj6OEgUdGyvK5Ruk41VfP7owdlNji7XDwQ7O4kfF5lY=; b=QPLjSQUHWurhFY+IkMVdAZZqFLoiFvts8ooYgQl1VhQ+SwfvCngJHD9/M0j3hCE6BhyGcR txPmFaL5EOGuXoHEZIyvZfsmAdh79GeV7cS/8+UjJJZO85m2geq2Z43Gw2p0b+ICj2CcmC Q0lzwAOkvDRmUxMy/NLD2ZvaGyQEFS8= Date: Mon, 25 Mar 2019 13:01:49 +0100 From: Borislav Petkov To: Junichi Nomura Cc: Dave Young , "fanc.fnst@cn.fujitsu.com" , "bhe@redhat.com" , "kasong@redhat.com" , "x86@kernel.org" , "kexec@lists.infradead.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH v2] x86/boot: Use EFI setup data if provided Message-ID: <20190325120149.GI12016@zn.tnic> References: <20190322152328.GD12472@zn.tnic> <20190325002740.GA6637@jeru.linux.bs1.fc.nec.co.jp> <20190325060128.GB9385@dhcp-128-65.nay.redhat.com> <20190325061929.GC9385@dhcp-128-65.nay.redhat.com> <20190325065921.GA11096@dhcp-128-65.nay.redhat.com> <20190325082720.GA20771@jeru.linux.bs1.fc.nec.co.jp> <51D9A7D1-49BF-4679-B102-0FC5AC300C9F@alien8.de> <20190325101509.GA13160@dhcp-128-65.nay.redhat.com> <701c8e69-e1d4-c653-1d87-1c41789d3d54@ce.jp.nec.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <701c8e69-e1d4-c653-1d87-1c41789d3d54@ce.jp.nec.com> 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, Mar 25, 2019 at 10:36:33AM +0000, Junichi Nomura wrote: > AFAIU, early parsing is new code in v5.1-rc1 to support kexec on systems > with hotpluggable memory with KASLR enabled. For systems that requires the > new feature, it may be ok to say "you need to use another kexec interface" > and/or "you need new kexec-tools". No, this exactly should *not* happen. kexec is already full of duct tape - don't need any more of that. So I suggested that efi_get_rsdp_addr() should exit early on in the kexeced kernel but making this all play nice with the kexec-ed kernel, as Dave suggests, is better. Now, my next question is: why does the RDSP address need to come from kexec(1) (by way of efi_setup_data) and why can't the kexec'ed kernel figure it out itself by parsing the EFI tables in a similar way to efi_get_rsdp_addr ? -- Regards/Gruss, Boris. Good mailing practices for 400: avoid top-posting and trim the reply.