From patchwork Thu Apr 7 00:06:21 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Luis Chamberlain X-Patchwork-Id: 8767631 Return-Path: X-Original-To: patchwork-xen-devel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 10A3CC0554 for ; Thu, 7 Apr 2016 00:09:20 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 2D7FE201CD for ; Thu, 7 Apr 2016 00:09:19 +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 2D577201ED for ; Thu, 7 Apr 2016 00:09:18 +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 1anxTQ-0002eD-1y; Thu, 07 Apr 2016 00:07:00 +0000 Received: from mail6.bemta5.messagelabs.com ([195.245.231.135]) by lists.xenproject.org with esmtp (Exim 4.84_2) (envelope-from ) id 1anxTO-0002do-2u for xen-devel@lists.xensource.com; Thu, 07 Apr 2016 00:06:58 +0000 Received: from [85.158.139.211] by server-15.bemta-5.messagelabs.com id A7/71-06546-1A4A5075; Thu, 07 Apr 2016 00:06:57 +0000 X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFvrNLMWRWlGSWpSXmKPExsVybKJsh+6CJaz hBhtf61rcm/Ke3YHRY3vfLvYAxijWzLyk/IoE1oyj/TPYC/6KV2x8e5CpgfGbcBcjF4eQwFRG iQ1f5rJDODOYJHadPcrcxcjBwSagK3HztkQXIyeHiECCxN2n35hBapgFvjFJ7D79jBkkISwQI TH14E9WEJtFQFXi+fJlLCA2r4CDxJabtxhBbAkBOYmWH7vBajgFHCWWn5oKZgsB1TQuXQJVky Exr2cOK4TtJbHoxiUoW03i6rlNzBMY+RYwMqxi1ChOLSpLLdI1NNdLKspMzyjJTczM0TU0MNX LTS0uTkxPzUlMKtZLzs/dxAgMFAYg2MF48bTnIUZJDiYlUV7XStZwIb6k/JTKjMTijPii0pzU 4kOMMhwcShK8fYuBcoJFqempFWmZOcCQhUlLcPAoifCuAEnzFhck5hZnpkOkTjEqSonzTgRJC IAkMkrz4NpgcXKJUVZKmJcR6BAhnoLUotzMElT5V4ziHIxKwrx5IFN4MvNK4Ka/AlrMBLS4Xp gJZHFJIkJKqoGxz2z6tfC0c3ZbHyRtP6N/ekrOTbN/TvLlqt8WVi94ulQzWapsUpO/5EOTzUx XQnR6N/k/U3r47+HpVXeMX5bYP15iy9cqeXZH4iQh7u3vHfy2LGdyPS90xGJpSYMi34Uje2R2 51SHcG84x6fc8qj0COPKN8t2egucrNx72/uNf/nZWkPHO1uclViKMxINtZiLihMBgJ8aEY4CA AA= X-Env-Sender: mcgrof@kernel.org X-Msg-Ref: server-5.tower-206.messagelabs.com!1459987615!33350471!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 54446 invoked from network); 7 Apr 2016 00:06:56 -0000 Received: from mail.kernel.org (HELO mail.kernel.org) (198.145.29.136) by server-5.tower-206.messagelabs.com with DHE-RSA-AES256-GCM-SHA384 encrypted SMTP; 7 Apr 2016 00:06:56 -0000 Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 58425201CD; Thu, 7 Apr 2016 00:06:54 +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 AF12A201E4; Thu, 7 Apr 2016 00:06:52 +0000 (UTC) From: "Luis R. Rodriguez" To: bp@alien8.de, hpa@zytor.com, tglx@linutronix.de, mingo@redhat.com, rusty@rustcorp.com.au Date: Wed, 6 Apr 2016 17:06:21 -0700 Message-Id: <1459987594-5434-2-git-send-email-mcgrof@kernel.org> X-Mailer: git-send-email 2.7.0 In-Reply-To: <1459987594-5434-1-git-send-email-mcgrof@kernel.org> References: <1459987594-5434-1-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: xen-devel@lists.xensource.com, matt@codeblueprint.co.uk, andrew.cooper3@citrix.com, x86@kernel.org, linux-kernel@vger.kernel.org, luto@amacapital.net, jlee@suse.com, "Luis R. Rodriguez" , lguest@lists.ozlabs.org, glin@suse.com, david.vrabel@citrix.com, boris.ostrovsky@oracle.com, andriy.shevchenko@linux.intel.com Subject: [Xen-devel] [PATCH v4 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. Cc: Andy Shevchenko Signed-off-by: Luis R. Rodriguez --- arch/x86/include/uapi/asm/bootparam.h | 36 ++++++++++++++++++++++++++++++++++- 1 file changed, 35 insertions(+), 1 deletion(-) diff --git a/arch/x86/include/uapi/asm/bootparam.h b/arch/x86/include/uapi/asm/bootparam.h index 329254373479..d03e2e9eefca 100644 --- a/arch/x86/include/uapi/asm/bootparam.h +++ b/arch/x86/include/uapi/asm/bootparam.h @@ -157,7 +157,41 @@ 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. + * @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,