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| author | Vladimir Murzin <vladimir.murzin@arm.com> | 2014-09-22 15:52:48 +0100 |
|---|---|---|
| committer | Jiri Slaby <jslaby@suse.cz> | 2015-04-30 11:15:10 +0200 |
| commit | 296cffc0f8705d35c2bcb754154ee4e829de238b (patch) | |
| tree | 55eacddc0645d7828f4330eef170c74b3b7c15c3 /arch/arm | |
| parent | 628d3e68cb2113cb0c4b935745e35a2efb7e944b (diff) | |
| download | lwn-296cffc0f8705d35c2bcb754154ee4e829de238b.tar.gz lwn-296cffc0f8705d35c2bcb754154ee4e829de238b.zip | |
arm: kvm: fix CPU hotplug
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 <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>
Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Diffstat (limited to 'arch/arm')
| -rw-r--r-- | arch/arm/kvm/arm.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c index 26ca5c694755..bac1ba5b3960 100644 --- a/arch/arm/kvm/arm.c +++ b/arch/arm/kvm/arm.c @@ -810,7 +810,8 @@ 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; } |