From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750900AbcBEAln (ORCPT ); Thu, 4 Feb 2016 19:41:43 -0500 Received: from mx1.redhat.com ([209.132.183.28]:33436 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750850AbcBEAlk (ORCPT ); Thu, 4 Feb 2016 19:41:40 -0500 Date: Fri, 5 Feb 2016 08:41:15 +0800 From: Dave Young To: Matt Fleming 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: <20160205004115.GA3651@dhcp-128-65.nay.redhat.com> 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> <20160204115656.GB2586@codeblueprint.co.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160204115656.GB2586@codeblueprint.co.uk> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 02/04/16 at 11:56am, Matt Fleming wrote: > 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. Ok, thanks. > > > 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. Thing is we support both kexec_load and kexec_file_load, if we do something in kernel loader we will need do same in userspace kexec-tools as well. Another way is we probably can retain the boot service areas for kexec boot, but yes it is another special handling for kexec :(. Is this way better to you? Thanks Dave