From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from tyo162.gate.nec.co.jp ([114.179.232.162]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1h8Ykv-00046V-4H for kexec@lists.infradead.org; Mon, 25 Mar 2019 23:11:51 +0000 From: Junichi Nomura Subject: Re: [PATCH v2] x86/boot: Use EFI setup data if provided Date: Mon, 25 Mar 2019 23:10:01 +0000 Message-ID: <20190325231000.GA9184@jeru.linux.bs1.fc.nec.co.jp> References: <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> <20190325120149.GI12016@zn.tnic> <20190325122302.GC13160@dhcp-128-65.nay.redhat.com> <20190325123229.GL12016@zn.tnic> In-Reply-To: <20190325123229.GL12016@zn.tnic> Content-Language: ja-JP Content-ID: <438C23D6AA3FC84F84B3753EDDE5A2C3@gisp.nec.co.jp> MIME-Version: 1.0 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "kexec" Errors-To: kexec-bounces+dwmw2=infradead.org@lists.infradead.org To: Borislav Petkov , Dave Young Cc: "fanc.fnst@cn.fujitsu.com" , "kasong@redhat.com" , "bhe@redhat.com" , "x86@kernel.org" , "kexec@lists.infradead.org" , "linux-kernel@vger.kernel.org" On 3/25/19 9:32 PM, Borislav Petkov wrote: > On Mon, Mar 25, 2019 at 08:23:02PM +0800, Dave Young wrote: >> Kexec saved the original physical addresses, and pass them to kexeced >> kernel via x86 setup_data, so both the early parsing or efi init code >> need to get those physical values from setup_data. > > So efi_get_rsdp_addr() needs to be refactored in such a way so that at > least the loop towards the end gets carved out into a separate function > - __efi_get_rsdp_addr() or so - which gets config_tables, nr_tables and > size as arguments and finds the RSDP address in the kexec-ed kernel. Since we still need to read systab for nr_tables and do signature check to determine if it's 32bit or 64bit for kexec-ed kernel, everything except the address of config_tables are common between normal boot and kexec boot. > So we'd need something like that: > > acpi_physical_address get_rsdp_addr(void) > { > acpi_physical_address pa; > > pa = get_acpi_rsdp(); > > if (!pa) > pa = boot_params->acpi_rsdp_addr; > > if (!pa) > pa = efi_get_rsdp_addr(); > > if (!pa) > pa = kexec_get_rdsp_addr(); <--- new function > > if (!pa) > pa = bios_get_rsdp_addr(); > > return pa; > } > > which would get config_tables from setup_data and call > __efi_get_rsdp_addr() to dig it out in the kexec'ed kernel. > > Junichi, ask if it is still unclear what needs to be done. efi_get_rsdp_addr() and kexec_get_rsdp_addr() could be implemented like this (sorry about the pseudo code): /* This is also used to check if the kernel is kexec-ed. */ unsigned long efi_get_setup_data_addr(void) { return the address of efi_setup_data if kexec-ed or 0 if not; } acpi_physical_address __efi_get_rsdp_addr(unsigned long config_tables) { // Do mostly same as the current efi_get_rsdp_addr(). // If config_tables is non-zero, use it instead of systab->tables. } acpi_physical_address efi_get_rsdp_addr(void) { if (efi_get_setup_data_addr()) return 0; return __efi_get_rsdp_addr(0); } acpi_physical_address kexec_get_rsdp_addr(void) { esd = (struct efi_setup_data *) efi_get_setup_data_addr(); if (esd && esd->tables) return __efi_get_rsdp_addr((unsigned long) esd->tables); return 0; } I don't think it looks nice.. Does this match what you envisage? -- Jun'ichi Nomura, NEC Corporation / NEC Solution Innovators, Ltd. _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec