From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:44704 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755406AbeCVNx4 (ORCPT ); Thu, 22 Mar 2018 09:53:56 -0400 Subject: Patch "x86/reboot: Turn off KVM when halting a CPU" has been added to the 4.9-stable tree To: fengtiantian@huawei.com, alexander.levin@microsoft.com, gregkh@linuxfoundation.org, mingo@kernel.org, pbonzini@redhat.com, peterz@infradead.org, qiuxishi@huawei.com, tglx@linutronix.de, torvalds@linux-foundation.org Cc: , From: Date: Thu, 22 Mar 2018 14:51:24 +0100 Message-ID: <152172668446217@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled x86/reboot: Turn off KVM when halting a CPU to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: x86-reboot-turn-off-kvm-when-halting-a-cpu.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From foo@baz Thu Mar 22 14:40:23 CET 2018 From: Tiantian Feng Date: Wed, 19 Apr 2017 18:18:39 +0200 Subject: x86/reboot: Turn off KVM when halting a CPU From: Tiantian Feng [ Upstream commit fba4f472b33aa81ca1836f57d005455261e9126f ] A CPU in VMX root mode will ignore INIT signals and will fail to bring up the APs after reboot. Therefore, on a panic we disable VMX on all CPUs before rebooting or triggering kdump. Do this when halting the machine as well, in case a firmware-level reboot does not perform a cold reset for all processors. Without doing this, rebooting the host may hang. Signed-off-by: Tiantian Feng Signed-off-by: Xishi Qiu [ Rewritten commit message. ] Signed-off-by: Paolo Bonzini Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: kvm@vger.kernel.org Link: http://lkml.kernel.org/r/20170419161839.30550-1-pbonzini@redhat.com Signed-off-by: Ingo Molnar Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- arch/x86/kernel/smp.c | 3 +++ 1 file changed, 3 insertions(+) --- a/arch/x86/kernel/smp.c +++ b/arch/x86/kernel/smp.c @@ -33,6 +33,7 @@ #include #include #include +#include /* * Some notes on x86 processor bugs affecting SMP operation: @@ -162,6 +163,7 @@ static int smp_stop_nmi_callback(unsigne if (raw_smp_processor_id() == atomic_read(&stopping_cpu)) return NMI_HANDLED; + cpu_emergency_vmxoff(); stop_this_cpu(NULL); return NMI_HANDLED; @@ -174,6 +176,7 @@ static int smp_stop_nmi_callback(unsigne asmlinkage __visible void smp_reboot_interrupt(void) { ipi_entering_ack_irq(); + cpu_emergency_vmxoff(); stop_this_cpu(NULL); irq_exit(); } Patches currently in stable-queue which might be from fengtiantian@huawei.com are queue-4.9/x86-reboot-turn-off-kvm-when-halting-a-cpu.patch