From patchwork Fri Apr 8 23:40:12 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Luis Chamberlain X-Patchwork-Id: 8787091 Return-Path: X-Original-To: patchwork-xen-devel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id BC4769FBEA for ; Fri, 8 Apr 2016 23:43:05 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id D6094202EB for ; Fri, 8 Apr 2016 23:43:04 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id E8D2220256 for ; Fri, 8 Apr 2016 23:43:03 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.84_2) (envelope-from ) id 1aog1C-0008S6-HD; Fri, 08 Apr 2016 23:40:50 +0000 Received: from mail6.bemta3.messagelabs.com ([195.245.230.39]) by lists.xenproject.org with esmtp (Exim 4.84_2) (envelope-from ) id 1aog1B-0008Rm-14 for xen-devel@lists.xensource.com; Fri, 08 Apr 2016 23:40:49 +0000 Received: from [85.158.137.68] by server-15.bemta-3.messagelabs.com id 20/84-03172-08148075; Fri, 08 Apr 2016 23:40:48 +0000 X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFmplkeJIrShJLcpLzFFi42I5NlG2Q7fekSP c4OJJZYt7U96zOzB6bO/bxR7AGMWamZeUX5HAmjFz72fmgrOSFUcnfmJuYJwj2sXIySEkMJVR 4t/S0i5GLiB7BpPEyz/3WLoYOTjYBHQlbt6WAKkREUiQuPv0GzNIDbPAORaJDZfms4EkhAUiJ LomfmcGsVkEVCWeTn7NBGLzCjhK/H67igXElhCQk2j5sZsVxOYUcJI4uO8PM8RiR4mrZ95A1W RIzOuZwwphe0ksunEJylaTuHpuE/MERr4FjAyrGNWLU4vKUot0jfWSijLTM0pyEzNzdA0NjPV yU4uLE9NTcxKTivWS83M3MQKDhAEIdjA2f3E6xCjJwaQkyrvtIXu4EF9SfkplRmJxRnxRaU5q 8SFGGQ4OJQne80Yc4UKCRanpqRVpmTnAcIVJS3DwKInwPgFJ8xYXJOYWZ6ZDpE4x6nJsWXBjL ZMQS15+XqqUOO8akCIBkKKM0jy4EbDYucQoKyXMywh0lBBPQWpRbmYJqvwrRnEORiVh3psgU3 gy80rgNr0COoIJ6IgL/GwgR5QkIqSkGhj79IwWB2lM+ViszHZbw/6U/dvaW4kr5/xpj0+4vl+ i41v9tibuXN1HRpNZGEJnJpwW07s7cbfUv3MqQtfdwkPfBG59oCmwr9G9QkPruX/bqlNex/LM VvpqBs/SXCY4fXmlYLu/gcA901hptk+zBevv/Fb2S/ZJPL7hq/M/mbmyN1YwTa77LqjEUpyRa KjFXFScCADTvORKmAIAAA== X-Env-Sender: mcgrof@kernel.org X-Msg-Ref: server-15.tower-31.messagelabs.com!1460158846!33464236!1 X-Originating-IP: [198.145.29.136] X-SpamReason: No, hits=0.0 required=7.0 tests= X-StarScan-Received: X-StarScan-Version: 8.28; banners=-,-,- X-VirusChecked: Checked Received: (qmail 35883 invoked from network); 8 Apr 2016 23:40:47 -0000 Received: from mail.kernel.org (HELO mail.kernel.org) (198.145.29.136) by server-15.tower-31.messagelabs.com with DHE-RSA-AES256-GCM-SHA384 encrypted SMTP; 8 Apr 2016 23:40:47 -0000 Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id B32492024D; Fri, 8 Apr 2016 23:40:44 +0000 (UTC) Received: from garbanzo.do-not-panic.com (c-73-15-241-2.hsd1.ca.comcast.net [73.15.241.2]) (using TLSv1.2 with cipher AES128-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id F164E2027D; Fri, 8 Apr 2016 23:40:42 +0000 (UTC) From: "Luis R. Rodriguez" To: bp@alien8.de, hpa@zytor.com, tglx@linutronix.de, mingo@redhat.com, rusty@rustcorp.com.au Date: Fri, 8 Apr 2016 16:40:12 -0700 Message-Id: <1460158825-13117-2-git-send-email-mcgrof@kernel.org> X-Mailer: git-send-email 2.7.0 In-Reply-To: <1460158825-13117-1-git-send-email-mcgrof@kernel.org> References: <1460158825-13117-1-git-send-email-mcgrof@kernel.org> X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Cc: kozerkov@parallels.com, matt@codeblueprint.co.uk, lv.zheng@intel.com, xen-devel@lists.xensource.com, joro@8bytes.org, x86@kernel.org, robert.moore@intel.com, linux-acpi@vger.kernel.org, glin@suse.com, lenb@kernel.org, josh@joshtriplett.org, jlee@suse.com, lguest@lists.ozlabs.org, boris.ostrovsky@oracle.com, andriy.shevchenko@linux.intel.com, toshi.kani@hp.com, andrew.cooper3@citrix.com, rjw@rjwysocki.net, linux-kernel@vger.kernel.org, luto@amacapital.net, "Luis R. Rodriguez" , david.vrabel@citrix.com, tiwai@suse.de Subject: [Xen-devel] [PATCH v5 01/14] x86/boot: enumerate documentation for the x86 hardware_subarch X-BeenThere: xen-devel@lists.xen.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: xen-devel-bounces@lists.xen.org Sender: "Xen-devel" X-Virus-Scanned: ClamAV using ClamSMTP Although hardware_subarch has been in place since the x86 boot protocol 2.07 it hasn't been used much. Enumerate current possible values to avoid misuses and help with semantics later at boot time should this be used further. These enums should only ever be used by architecture x86 code, and all that code should be well contained and compartamentalized, clarify that as well. v2: updates documentation further -- be a bit more pedantic about annotating care and use of these guys. v3: Use s/SOC/SoC and also anntoate that both domU and dom0 are both currently supported through the PV boot path. Cc: Andy Shevchenko Signed-off-by: Luis R. Rodriguez --- arch/x86/include/uapi/asm/bootparam.h | 37 ++++++++++++++++++++++++++++++++++- 1 file changed, 36 insertions(+), 1 deletion(-) diff --git a/arch/x86/include/uapi/asm/bootparam.h b/arch/x86/include/uapi/asm/bootparam.h index 329254373479..bf9fea2f4591 100644 --- a/arch/x86/include/uapi/asm/bootparam.h +++ b/arch/x86/include/uapi/asm/bootparam.h @@ -157,7 +157,42 @@ struct boot_params { __u8 _pad9[276]; /* 0xeec */ } __attribute__((packed)); -enum { +/** + * enum x86_hardware_subarch - x86 hardware subarchitecture + * + * The x86 hardware_subarch and hardware_subarch_data were added as of the x86 + * boot protocol 2.07 to help distinguish and support custom x86 boot + * sequences. This enum represents accepted values for the x86 + * hardware_subarch. Custom x86 boot sequences (not X86_SUBARCH_PC) do not + * have or simply *cannot* make use of natural stubs like BIOS or EFI, the + * hardware_subarch can be used on the Linux entry path to revector to a + * subarchitecture stub when needed. This subarchitecture stub can be used to + * set up Linux boot parameters or for special care to account for nonstandard + * handling of page tables. + * + * These enums should only ever be used by x86 code, and the code that uses + * it should be well contained and compartamentalized. + * + * KVM and Xen HVM do not have a subarch as these are expected to follow + * standard x86 boot entries. If there is a genuine need for "hypervisor" type + * that should be considered separately in the future. Future guest types + * should seriously consider working with standard x86 boot stubs such as + * the BIOS or EFI boot stubs. + * + * @X86_SUBARCH_PC: Should be used if the hardware is enumerable using standard + * PC mechanisms (PCI, ACPI) and doesn't need a special boot flow. + * @X86_SUBARCH_LGUEST: Used for x86 hypervisor demo, lguest + * @X86_SUBARCH_XEN: Used for Xen guest types which follow the PV boot path, + * which start at asm startup_xen() entry point and later jump to the C + * xen_start_kernel() entry point. Both domU and dom0 type of guests are + * currently supportd through this PV boot path. + * @X86_SUBARCH_INTEL_MID: Used for Intel MID (Mobile Internet Device) platform + * systems which do not have the PCI legacy interfaces. + * @X86_SUBARCH_CE4100: Used for Intel CE media processor (CE4100) SoC for + * for settop boxes and media devices, the use of a subarch for CE4100 + * is more of a hack... + */ +enum x86_hardware_subarch { X86_SUBARCH_PC = 0, X86_SUBARCH_LGUEST, X86_SUBARCH_XEN,