From patchwork Fri Dec 9 18:24:06 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andy Lutomirski X-Patchwork-Id: 9468885 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 2C660607D8 for ; Fri, 9 Dec 2016 18:26:32 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 233762864C for ; Fri, 9 Dec 2016 18:26:32 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 17DA228680; Fri, 9 Dec 2016 18:26:32 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 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.wl.linuxfoundation.org (Postfix) with ESMTPS id 80E502864C for ; Fri, 9 Dec 2016 18:26:31 +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 1cFPqI-0003zR-MW; Fri, 09 Dec 2016 18:24:22 +0000 Received: from mail6.bemta3.messagelabs.com ([195.245.230.39]) by lists.xenproject.org with esmtp (Exim 4.84_2) (envelope-from ) id 1cFPqH-0003zB-GH for Xen-devel@lists.xen.org; Fri, 09 Dec 2016 18:24:21 +0000 Received: from [85.158.137.68] by server-17.bemta-3.messagelabs.com id 04/12-31715-4D6FA485; Fri, 09 Dec 2016 18:24:20 +0000 X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFprHIsWRWlGSWpSXmKPExsVybKJsh+6Vb14 RBh928Vos+biYxYHR4+ju30wBjFGsmXlJ+RUJrBlP12xhK5jFUzH/6QO2BsaNXF2MXBxCAlMZ JQ4+Xs8E4cxikrjUcgbI4eBgE1CXaOn0BTFFBIQklt6tAylhFjjNKnG/5QBjFyMnh7BAmMTFE y+ZQWwWAVWJpls7weK8AqESG3bfYgWxJQTkJC5t+wJWwylgLPHo53wwW0jASGL1kpl4xSUEMi Tm9cyBmuMlsejGJShbTeLquU3MExgFFjAyrGLUKE4tKkst0jU01EsqykzPKMlNzMzRNTQw1st NLS5OTE/NSUwq1kvOz93ECAwrBiDYwbj6t9MhRkkOJiVR3mImrwghvqT8lMqMxOKM+KLSnNTi Q4wyHBxKErznvgLlBItS01Mr0jJzgAEOk5bg4FES4f0EkuYtLkjMLc5Mh0idYtTlWDBn5VMmI Za8/LxUKXHeuyBFAiBFGaV5cCNg0XaJUVZKmJcR6CghnoLUotzMElT5V4ziHIxKwrz2IFN4Mv NK4Da9AjqCCeiIeTfcQY4oSURISTUwzhMPjuGvuOwcvEvmx3Sp6SFr7L7N02fMO29lvylv8sw V0uHLvteH3OB43Vd4kO181rWJT7W/1txVNfU7NrnPK15veudx3e4pVT7qf3Rn7OG/3hlnee19 XPH9cyX3lKd9m5Xemu2wnDlpdcKNdQfnbZR6JptWc3fh29u3Nlk8aWUtuuX+d4FYoxJLcUaio RZzUXEiAIeaJa2xAgAA X-Env-Sender: luto@kernel.org X-Msg-Ref: server-5.tower-31.messagelabs.com!1481307858!72152860!1 X-Originating-IP: [198.145.29.136] X-SpamReason: No, hits=0.0 required=7.0 tests= X-StarScan-Received: X-StarScan-Version: 9.0.16; banners=-,-,- X-VirusChecked: Checked Received: (qmail 32908 invoked from network); 9 Dec 2016 18:24:20 -0000 Received: from mail.kernel.org (HELO mail.kernel.org) (198.145.29.136) by server-5.tower-31.messagelabs.com with DHE-RSA-AES256-GCM-SHA384 encrypted SMTP; 9 Dec 2016 18:24:20 -0000 Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 602B52035E; Fri, 9 Dec 2016 18:24:17 +0000 (UTC) Received: from localhost (c-71-202-137-17.hsd1.ca.comcast.net [71.202.137.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 8DC742034A; Fri, 9 Dec 2016 18:24:14 +0000 (UTC) From: Andy Lutomirski To: x86@kernel.org Date: Fri, 9 Dec 2016 10:24:06 -0800 Message-Id: <82acde18a108b8e353180dd6febcc2876df33f24.1481307769.git.luto@kernel.org> X-Mailer: git-send-email 2.9.3 In-Reply-To: References: In-Reply-To: References: X-Virus-Scanned: ClamAV using ClamSMTP Cc: Juergen Gross , One Thousand Gnomes , Denys Vlasenko , Andy Lutomirski , Josh Poimboeuf , Peter Zijlstra , Brian Gerst , "H . Peter Anvin" , "linux-kernel@vger.kernel.org" , Matthew Whitehead , Borislav Petkov , Henrique de Moraes Holschuh , Andrew Cooper , Boris Ostrovsky , xen-devel , Linus Torvalds , Thomas Gleixner Subject: [Xen-devel] [PATCH v4 2/4] Revert "x86/boot: Fail the boot if !M486 and CPUID is missing" 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 This reverts commit ed68d7e9b9cfb64f3045ffbcb108df03c09a0f98. The patch wasn't quite correct -- there are non-Intel (and hence non-486) CPUs that we support that don't have CPUID. Since we no longer require CPUID for sync_core(), just revert the patch. I think the relevant CPUs are Geode and Elan, but I'm not sure. In principle, we should try to do better at identifying CPUID-less CPUs in early boot, but that's more complicated. Reported-by: One Thousand Gnomes Cc: Matthew Whitehead Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Josh Poimboeuf Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Signed-off-by: Andy Lutomirski --- arch/x86/boot/cpu.c | 6 ------ 1 file changed, 6 deletions(-) diff --git a/arch/x86/boot/cpu.c b/arch/x86/boot/cpu.c index 4224ede43b4e..26240dde081e 100644 --- a/arch/x86/boot/cpu.c +++ b/arch/x86/boot/cpu.c @@ -87,12 +87,6 @@ int validate_cpu(void) return -1; } - if (CONFIG_X86_MINIMUM_CPU_FAMILY <= 4 && !IS_ENABLED(CONFIG_M486) && - !has_eflag(X86_EFLAGS_ID)) { - printf("This kernel requires a CPU with the CPUID instruction. Build with CONFIG_M486=y to run on this CPU.\n"); - return -1; - } - if (err_flags) { puts("This kernel requires the following features " "not present on the CPU:\n");