From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755544AbYLIUjW (ORCPT ); Tue, 9 Dec 2008 15:39:22 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755346AbYLIUYm (ORCPT ); Tue, 9 Dec 2008 15:24:42 -0500 Received: from mx2.redhat.com ([66.187.237.31]:34862 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754778AbYLIUXK (ORCPT ); Tue, 9 Dec 2008 15:23:10 -0500 From: Avi Kivity To: kvm@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Eduardo Habkost Subject: [PATCH 27/44] kdump: forcibly disable VMX and SVM on machine_crash_shutdown() Date: Tue, 9 Dec 2008 22:22:42 +0200 Message-Id: <1228854179-23002-28-git-send-email-avi@redhat.com> In-Reply-To: <1228854179-23002-1-git-send-email-avi@redhat.com> References: <1228854179-23002-1-git-send-email-avi@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Eduardo Habkost We need to disable virtualization extensions on all CPUs before booting the kdump kernel, otherwise the kdump kernel booting will fail, and rebooting after the kdump kernel did its task may also fail. We do it using cpu_emergency_vmxoff() and cpu_emergency_svm_disable(), that should always work, because those functions check if the CPUs support SVM or VMX before doing their tasks. Signed-off-by: Eduardo Habkost Signed-off-by: Avi Kivity --- arch/x86/kernel/crash.c | 18 ++++++++++++++++++ 1 files changed, 18 insertions(+), 0 deletions(-) diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c index d84a852..c689d19 100644 --- a/arch/x86/kernel/crash.c +++ b/arch/x86/kernel/crash.c @@ -26,6 +26,7 @@ #include #include #include +#include #include @@ -49,6 +50,15 @@ static void kdump_nmi_callback(int cpu, struct die_args *args) #endif crash_save_cpu(regs, cpu); + /* Disable VMX or SVM if needed. + * + * We need to disable virtualization on all CPUs. + * Having VMX or SVM enabled on any CPU may break rebooting + * after the kdump kernel has finished its task. + */ + cpu_emergency_vmxoff(); + cpu_emergency_svm_disable(); + disable_local_APIC(); } @@ -80,6 +90,14 @@ void native_machine_crash_shutdown(struct pt_regs *regs) local_irq_disable(); kdump_nmi_shootdown_cpus(); + + /* Booting kdump kernel with VMX or SVM enabled won't work, + * because (among other limitations) we can't disable paging + * with the virt flags. + */ + cpu_emergency_vmxoff(); + cpu_emergency_svm_disable(); + lapic_shutdown(); #if defined(CONFIG_X86_IO_APIC) disable_IO_APIC(); -- 1.6.0.3