From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760149Ab2HJKef (ORCPT ); Fri, 10 Aug 2012 06:34:35 -0400 Received: from Chamillionaire.breakpoint.cc ([80.244.247.6]:41655 "EHLO Chamillionaire.breakpoint.cc" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751317Ab2HJKee (ORCPT ); Fri, 10 Aug 2012 06:34:34 -0400 From: Florian Westphal To: kvm@vger.kernel.org Cc: avi@redhat.com, linux-kernel@vger.kernel.org, Florian Westphal Subject: [PATCH] kvm: disable stealtime via reboot notifier to avoid mem corruption Date: Fri, 10 Aug 2012 12:36:22 +0200 Message-Id: <1344594982-8516-1-git-send-email-fw@strlen.de> X-Mailer: git-send-email 1.7.8.6 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org else, we get memory corruption on reboot; found when tracking down initramfs unpack error on initial reboot (with qemu-kvm -smp 2, no problem with single-core). problem with doing it via kvm_shutdown() is that this file depends on CONFIG_KVM_CLOCK, also its not enough to call it for one cpu only. Signed-off-by: Florian Westphal --- not subscribed, please CC on replies. Also, I don't know much about kvm or kexec, so its possible that i missed something. In any case, this seems to fix the initramfs corruption for me. patch is against virt/kvm/kvm.git. arch/x86/kernel/kvm.c | 1 + arch/x86/kernel/kvmclock.c | 1 - 2 files changed, 1 insertions(+), 1 deletions(-) diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c index c1d61ee..1596cc8 100644 --- a/arch/x86/kernel/kvm.c +++ b/arch/x86/kernel/kvm.c @@ -354,6 +354,7 @@ static void kvm_pv_guest_cpu_reboot(void *unused) if (kvm_para_has_feature(KVM_FEATURE_PV_EOI)) wrmsrl(MSR_KVM_PV_EOI_EN, 0); kvm_pv_disable_apf(); + kvm_disable_steal_time(); } static int kvm_pv_reboot_notify(struct notifier_block *nb, diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c index f1b42b3..5a2fa7d 100644 --- a/arch/x86/kernel/kvmclock.c +++ b/arch/x86/kernel/kvmclock.c @@ -191,7 +191,6 @@ static void kvm_crash_shutdown(struct pt_regs *regs) static void kvm_shutdown(void) { native_write_msr(msr_kvm_system_time, 0, 0); - kvm_disable_steal_time(); native_machine_shutdown(); } -- 1.7.8.6