From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965020AbcBDL5C (ORCPT ); Thu, 4 Feb 2016 06:57:02 -0500 Received: from mail-wm0-f49.google.com ([74.125.82.49]:35908 "EHLO mail-wm0-f49.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756152AbcBDL47 (ORCPT ); Thu, 4 Feb 2016 06:56:59 -0500 Date: Thu, 4 Feb 2016 11:56:56 +0000 From: Matt Fleming To: Dave Young Cc: linux-efi@vger.kernel.org, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, Borislav Petkov , linux-acpi@vger.kernel.org, "Rafael J. Wysocki" , Josh Triplett , Matthew Garrett Subject: Re: [PATCH] x86/efi: skip bgrt init for kexec reboot Message-ID: <20160204115656.GB2586@codeblueprint.co.uk> References: <20160127112044.GA2961@dhcp-128-65.nay.redhat.com> <20160203214200.GA15110@dhcp-128-65.nay.redhat.com> <20160203225333.GA31246@codeblueprint.co.uk> <20160204100329.GA2586@codeblueprint.co.uk> <20160204110903.GA2977@dhcp-128-65.nay.redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160204110903.GA2977@dhcp-128-65.nay.redhat.com> User-Agent: Mutt/1.5.24+41 (02bc14ed1569) (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 04 Feb, at 07:09:03PM, Dave Young wrote: > > Consider the original code path, maybe change it to efi_kexec_setup will > be better to remind people? Or something else like a wraper function with > similar name.. Possibly. I had considered adding a new efi_enabled() bit for KEXEC_BOOT, but I'm worried that'll just encourage more uses. The best approach is going to be to see whether we can reduce the uses of efi_setup and the associated special code. Once we've completed that exercise, we can think about the best name for this variable. > For building ACPI tables we need do it in kernel instead of kexec-tools > because of kexec_file_load for secure boot case so we still need a conditional > code path for kexec.. Note that it may not be necessary to build any ACPI tables at all, provided that things like acpi_get_table() fail gracefully for kexec. I'm assuming that's the problem that you discovered when writing this patch. And yes, I don't expect you can build the ACPI table from userspace, but it should at least be possible to do it in setup_boot_parameters() or so when you setup the EFI table pointers (efi.config_tables), etc. I think that would be a natural home for this feature. > Also I'm not sure how to rebuild ACPI tables, it is easy or hard. Let me > checking the detail and think more about it. Thanks.