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authorVladimir Murzin <vladimir.murzin@arm.com>2014-09-22 18:52:48 +0400
committerChristoffer Dall <christoffer.dall@linaro.org>2014-09-29 18:02:34 +0400
commit37a34ac1d4775aafbc73b9db53c7daebbbc67e6a (patch)
tree1148896f37f73fddb00f4c81574942425856c3f3 /arch/arm/kvm
parent0496daa5cf99741ce8db82686b4c7446a37feabb (diff)
downloadlinux-37a34ac1d4775aafbc73b9db53c7daebbbc67e6a.tar.xz
arm: kvm: fix CPU hotplug
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 <vladimir.murzin@arm.com> Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Diffstat (limited to 'arch/arm/kvm')
-rw-r--r--arch/arm/kvm/arm.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index 779605122f32..45e5f67e63b1 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -808,7 +808,8 @@ static int hyp_init_cpu_notify(struct notifier_block *self,
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;
}