From: Vladimir Murzin Date: Mon, 22 Sep 2014 14:52:48 +0000 (+0100) Subject: arm: kvm: fix CPU hotplug X-Git-Tag: fixes-against-v3.18-rc2~42^2~11 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=37a34ac1d4775aafbc73b9db53c7daebbbc67e6a;p=pandora-kernel.git 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 Acked-by: Lorenzo Pieralisi Acked-by: Marc Zyngier Signed-off-by: Christoffer Dall --- Reading git-diff-tree failed