From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759553Ab3BMA6c (ORCPT ); Tue, 12 Feb 2013 19:58:32 -0500 Received: from terminus.zytor.com ([198.137.202.10]:59244 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757219Ab3BMA6a (ORCPT ); Tue, 12 Feb 2013 19:58:30 -0500 Date: Tue, 12 Feb 2013 16:57:16 -0800 From: "tip-bot for K. Y. Srinivasan" Message-ID: Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@kernel.org, kys@microsoft.com, tglx@linutronix.de, hpa@linux.intel.com Reply-To: mingo@kernel.org, hpa@zytor.com, linux-kernel@vger.kernel.org, kys@microsoft.com, tglx@linutronix.de, hpa@linux.intel.com In-Reply-To: <1359940959-32168-2-git-send-email-kys@microsoft.com> References: <1359940959-32168-2-git-send-email-kys@microsoft.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/hyperv] X86: Add a check to catch Xen emulation of Hyper-V Git-Commit-ID: db34bbb767bdfa1ebed7214b876fe01c5b7ee457 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.7 (terminus.zytor.com [127.0.0.1]); Tue, 12 Feb 2013 16:57:21 -0800 (PST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: db34bbb767bdfa1ebed7214b876fe01c5b7ee457 Gitweb: http://git.kernel.org/tip/db34bbb767bdfa1ebed7214b876fe01c5b7ee457 Author: K. Y. Srinivasan AuthorDate: Sun, 3 Feb 2013 17:22:38 -0800 Committer: H. Peter Anvin CommitDate: Tue, 12 Feb 2013 16:27:03 -0800 X86: Add a check to catch Xen emulation of Hyper-V Xen emulates Hyper-V to host enlightened Windows. Looks like this emulation may be turned on by default even for Linux guests. Check and fail Hyper-V detection if we are on Xen. [ hpa: the problem here is that Xen doesn't emulate Hyper-V well enough, and if the Xen support isn't compiled in, we end up stubling over the Hyper-V emulation and try to activate it -- and it fails. ] Signed-off-by: K. Y. Srinivasan Link: http://lkml.kernel.org/r/1359940959-32168-2-git-send-email-kys@microsoft.com Signed-off-by: H. Peter Anvin --- arch/x86/kernel/cpu/mshyperv.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c index 646d192..4dab317 100644 --- a/arch/x86/kernel/cpu/mshyperv.c +++ b/arch/x86/kernel/cpu/mshyperv.c @@ -30,6 +30,13 @@ static bool __init ms_hyperv_platform(void) if (!boot_cpu_has(X86_FEATURE_HYPERVISOR)) return false; + /* + * Xen emulates Hyper-V to support enlightened Windows. + * Check to see first if we are on a Xen Hypervisor. + */ + if (xen_cpuid_base()) + return false; + cpuid(HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS, &eax, &hyp_signature[0], &hyp_signature[1], &hyp_signature[2]);