From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:44376 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752856AbbGASXa (ORCPT ); Wed, 1 Jul 2015 14:23:30 -0400 Subject: Patch "arm: kvm: fix CPU hotplug" has been added to the 3.14-stable tree To: vladimir.murzin@arm.com, christoffer.dall@linaro.org, gregkh@linuxfoundation.org, lorenzo.pieralisi@arm.com, marc.zyngier@arm.com, shannon.zhao@linaro.org Cc: , From: Date: Wed, 01 Jul 2015 11:23:29 -0700 Message-ID: <143577500923879@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 arm: kvm: fix CPU hotplug to the 3.14-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: arm-kvm-fix-cpu-hotplug.patch and it can be found in the queue-3.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From 37a34ac1d4775aafbc73b9db53c7daebbbc67e6a Mon Sep 17 00:00:00 2001 From: Vladimir Murzin Date: Mon, 22 Sep 2014 15:52:48 +0100 Subject: arm: kvm: fix CPU hotplug From: Vladimir Murzin commit 37a34ac1d4775aafbc73b9db53c7daebbbc67e6a upstream. On some platforms with no power management capabilities, the hotplug implementation is allowed to return from a smp_ops.cpu_die() call as a function return. Upon a CPU onlining event, the KVM CPU notifier tries to reinstall the hyp stub, which fails on platform where no reset took place following a hotplug event, with the message: CPU1: smp_ops.cpu_die() returned, trying to resuscitate CPU1: Booted secondary processor Kernel panic - not syncing: unexpected prefetch abort in Hyp mode at: 0x80409540 unexpected data abort in Hyp mode at: 0x80401fe8 unexpected HVC/SVC trap in Hyp mode at: 0x805c6170 since KVM code is trying to reinstall the stub on a system where it is already configured. To prevent this issue, this patch adds a check in the KVM hotplug notifier that detects if the HYP stub really needs re-installing when a CPU is onlined and skips the installation call if the stub is already in place, which means that the CPU has not been reset. Signed-off-by: Vladimir Murzin Acked-by: Lorenzo Pieralisi Acked-by: Marc Zyngier Signed-off-by: Christoffer Dall Signed-off-by: Shannon Zhao Signed-off-by: Greg Kroah-Hartman --- arch/arm/kvm/arm.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/arch/arm/kvm/arm.c +++ b/arch/arm/kvm/arm.c @@ -825,7 +825,8 @@ static int hyp_init_cpu_notify(struct no switch (action) { case CPU_STARTING: case CPU_STARTING_FROZEN: - cpu_init_hyp_mode(NULL); + if (__hyp_get_vectors() == hyp_default_vectors) + cpu_init_hyp_mode(NULL); break; } Patches currently in stable-queue which might be from vladimir.murzin@arm.com are queue-3.14/arm-kvm-fix-cpu-hotplug.patch