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=-8.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 88125C43387 for ; Wed, 16 Jan 2019 06:51:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6015D20859 for ; Wed, 16 Jan 2019 06:51:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388213AbfAPGvh (ORCPT ); Wed, 16 Jan 2019 01:51:37 -0500 Received: from mx1.redhat.com ([209.132.183.28]:50982 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388157AbfAPGvh (ORCPT ); Wed, 16 Jan 2019 01:51:37 -0500 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 64FFA58E46; Wed, 16 Jan 2019 06:51:36 +0000 (UTC) Received: from dhcp-128-65.nay.redhat.com (ovpn-12-86.pek2.redhat.com [10.72.12.86]) by smtp.corp.redhat.com (Postfix) with ESMTPS id AACF55D961; Wed, 16 Jan 2019 06:51:30 +0000 (UTC) Date: Wed, 16 Jan 2019 14:51:26 +0800 From: Dave Young To: Kairui Song Cc: Borislav Petkov , linux-kernel@vger.kernel.org, tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, x86@kernel.org, Baoquan He , kexec@lists.infradead.org, akpm@linux-foundation.org, robert.moore@intel.com, erik.schmauss@intel.com, rafael.j.wysocki@intel.com, Len Brown , Chao Fan Subject: Re: [PATCH v2 2/2] x86, kexec_file_load: make it work with efi=noruntime or efi=old_map Message-ID: <20190116065126.GC6468@dhcp-128-65.nay.redhat.com> References: <20190115095834.22617-1-kasong@redhat.com> <20190115095834.22617-3-kasong@redhat.com> <20190115231005.GF6596@zn.tnic> <20190116033243.GB9649@dhcp-128-65.nay.redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.9.5 (2018-04-13) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.39]); Wed, 16 Jan 2019 06:51:36 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/16/19 at 01:09pm, Kairui Song wrote: > On Wed, Jan 16, 2019 at 11:32 AM Dave Young wrote: > > > > On 01/16/19 at 12:10am, Borislav Petkov wrote: > > > On Tue, Jan 15, 2019 at 05:58:34PM +0800, Kairui Song wrote: > > > > When efi=noruntime or efi=oldmap is used, EFI services won't be available > > > > in the second kernel, therefore the second kernel will not be able to get > > > > the ACPI RSDP address from firmware by calling EFI services and won't > > > > boot. Previously we are expecting the user to set the acpi_rsdp= > > > > on kernel command line for second kernel as there was no way to pass RSDP > > > > address to second kernel. > > > > > > > > After commit e6e094e053af ('x86/acpi, x86/boot: Take RSDP address from > > > > boot params if available'), now it's possible to set an acpi_rsdp_addr > > > > parameter in the boot_params passed to second kernel, this commit make > > > > use of it, detect and set the RSDP address when it's required for second > > > > kernel to boot. > > > > > > > > Tested with an EFI enabled KVM VM with efi=noruntime. > > > > > > > > Suggested-by: Dave Young > > > > Signed-off-by: Kairui Song > > > > --- > > > > arch/x86/kernel/kexec-bzimage64.c | 21 +++++++++++++++++++++ > > > > drivers/acpi/acpica/tbxfroot.c | 3 +-- > > > > include/acpi/acpixf.h | 2 +- > > > > 3 files changed, 23 insertions(+), 3 deletions(-) > > > > > > > > diff --git a/arch/x86/kernel/kexec-bzimage64.c b/arch/x86/kernel/kexec-bzimage64.c > > > > index 53917a3ebf94..0a90dcbd041f 100644 > > > > --- a/arch/x86/kernel/kexec-bzimage64.c > > > > +++ b/arch/x86/kernel/kexec-bzimage64.c > > > > @@ -20,6 +20,7 @@ > > > > #include > > > > #include > > > > #include > > > > +#include > > > > > > > > #include > > > > #include > > > > @@ -255,8 +256,28 @@ setup_boot_parameters(struct kimage *image, struct boot_params *params, > > > > /* Setup EFI state */ > > > > setup_efi_state(params, params_load_addr, efi_map_offset, efi_map_sz, > > > > efi_setup_data_offset); > > > > + > > > > +#ifdef CONFIG_ACPI > > > > + /* Setup ACPI RSDP pointer in case EFI is not available in second kernel */ > > > > + if (!acpi_disabled && (!efi_enabled(EFI_RUNTIME_SERVICES) || efi_enabled(EFI_OLD_MEMMAP))) { > > > > + /* Copied from acpi_os_get_root_pointer accordingly */ > > > > + params->acpi_rsdp_addr = boot_params.acpi_rsdp_addr; > > > > + if (!params->acpi_rsdp_addr) { > > > > + if (efi_enabled(EFI_CONFIG_TABLES)) { > > > > + if (efi.acpi20 != EFI_INVALID_TABLE_ADDR) > > > > + params->acpi_rsdp_addr = efi.acpi20; > > > > + else if (efi.acpi != EFI_INVALID_TABLE_ADDR) > > > > + params->acpi_rsdp_addr = efi.acpi; > > > > + } else if (IS_ENABLED(CONFIG_ACPI_LEGACY_TABLES_LOOKUP)) { > > > > + acpi_find_root_pointer(¶ms->acpi_rsdp_addr); > > > > + } > > > > + } > > > > + if (!params->acpi_rsdp_addr) > > > > + pr_warn("RSDP is not available for second kernel\n"); > > > > + } > > > > #endif > > > > > > Amazing the amount of ACPI RDSP parsing and fiddling patches flying > > > around these days... > > > > > > In any case, this needs to be synchronized with: > > > > > > https://lkml.kernel.org/r/20190107032243.25324-1-fanc.fnst@cn.fujitsu.com > > > > > > and checked whether the above can be used instead of sprinkling of ACPI > > > parsing code left and right. > > > > Both Baoquan and Chao are cced for comments. > > The above KASLR patches seems some early code to parsing acpi, but I think in this > > patch just call acpi function to get the root pointer no need to add the > > duplicate logic of if/else/else if. > > > > Kairui, do you have any reason for the checking? Is there some simple > > acpi function to just return the root pointer? > > Hi, I'm afraid that would require moving multiple structure and > function out of .init, > acpi_os_get_root_pointer is an ideal function to do the job, but it's > in .init and (on x86) it will call x86_init.acpi.get_root_pointer (by > calling acpi_arch_get_root_pointer) which will also be freed after > init, unless I change the x86_init, move they out of .init which is > not a good idea. > > Maybe I could split acpi_os_get_root_pointer into two, one gets freed > after init, one for later use. But the "acpi_rsdp_addr" trick only > works for x86, and this would change more common acpi driver code so > not sure if a good idea. Can the acpi root pointer be saved after initialized? If that is good then a new function to get it would be easier. But need opinion from acpi people. Thanks Dave