Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S967172Ab3DRPMn (ORCPT ); Thu, 18 Apr 2013 11:12:43 -0400 Received: from p3plsmtps2ded04.prod.phx3.secureserver.net ([208.109.80.198]:33655 "EHLO p3plsmtps2ded04.prod.phx3.secureserver.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S966861Ab3DRPMl (ORCPT ); Thu, 18 Apr 2013 11:12:41 -0400 x-originating-ip: 72.167.245.219 From: "K. Y. Srinivasan" To: gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, devel@linuxdriverproject.org, olaf@aepfle.de, apw@canonical.com, jasowang@redhat.com, JBeulich@suse.com, hpa@zytor.com, mst@redhat.com Cc: "K. Y. Srinivasan" Subject: [PATCH 1/1] X86: Handle Xen emulation of Hyper-V more gracefully Date: Thu, 18 Apr 2013 08:44:46 -0700 Message-Id: <1366299886-6399-1-git-send-email-kys@microsoft.com> X-Mailer: git-send-email 1.7.4.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1969 Lines: 60 Install the Hyper-V specific interrupt handler only when needed. This would permit us to get rid of the Xen check. Note that when the vmbus drivers invokes the call to register its handler, we are sure to be running on Hyper-V. Signed-off-by: K. Y. Srinivasan --- arch/x86/kernel/cpu/mshyperv.c | 18 +++++------------- 1 files changed, 5 insertions(+), 13 deletions(-) diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c index a7d26d8..8f4be53 100644 --- a/arch/x86/kernel/cpu/mshyperv.c +++ b/arch/x86/kernel/cpu/mshyperv.c @@ -35,13 +35,6 @@ 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]); @@ -82,12 +75,6 @@ static void __init ms_hyperv_init_platform(void) if (ms_hyperv.features & HV_X64_MSR_TIME_REF_COUNT_AVAILABLE) clocksource_register_hz(&hyperv_cs, NSEC_PER_SEC/100); -#if IS_ENABLED(CONFIG_HYPERV) - /* - * Setup the IDT for hypervisor callback. - */ - alloc_intr_gate(HYPERVISOR_CALLBACK_VECTOR, hyperv_callback_vector); -#endif } const __refconst struct hypervisor_x86 x86_hyper_ms_hyperv = { @@ -103,6 +90,11 @@ static irq_handler_t vmbus_isr; void hv_register_vmbus_handler(int irq, irq_handler_t handler) { + /* + * Setup the IDT for hypervisor callback. + */ + alloc_intr_gate(HYPERVISOR_CALLBACK_VECTOR, hyperv_callback_vector); + vmbus_irq = irq; vmbus_isr = handler; } -- 1.7.4.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/