From: James Morse Date: Mon, 22 Jan 2018 18:19:06 +0000 (+0000) Subject: KVM: arm/arm64: Handle CPU_PM_ENTER_FAILED X-Git-Tag: v4.9.82~35 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f6741799aa5321c52a83ff5d9ce753165774d63c;p=thirdparty%2Fkernel%2Fstable.git KVM: arm/arm64: Handle CPU_PM_ENTER_FAILED commit 58d6b15e9da5042a99c9c30ad725792e4569150e upstream. cpu_pm_enter() calls the pm notifier chain with CPU_PM_ENTER, then if there is a failure: CPU_PM_ENTER_FAILED. When KVM receives CPU_PM_ENTER it calls cpu_hyp_reset() which will return us to the hyp-stub. If we subsequently get a CPU_PM_ENTER_FAILED, KVM does nothing, leaving the CPU running with the hyp-stub, at odds with kvm_arm_hardware_enabled. Add CPU_PM_ENTER_FAILED as a fallthrough for CPU_PM_EXIT, this reloads KVM based on kvm_arm_hardware_enabled. This is safe even if CPU_PM_ENTER never gets as far as KVM, as cpu_hyp_reinit() calls cpu_hyp_reset() to make sure the hyp-stub is loaded before reloading KVM. Fixes: 67f691976662 ("arm64: kvm: allows kvm cpu hotplug") CC: Lorenzo Pieralisi Reviewed-by: Christoffer Dall Signed-off-by: James Morse Signed-off-by: Christoffer Dall Signed-off-by: Greg Kroah-Hartman --- diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c index 19b5f5c1c0ff3..c38bfbeec306e 100644 --- a/arch/arm/kvm/arm.c +++ b/arch/arm/kvm/arm.c @@ -1165,6 +1165,7 @@ static int hyp_init_cpu_pm_notifier(struct notifier_block *self, cpu_hyp_reset(); return NOTIFY_OK; + case CPU_PM_ENTER_FAILED: case CPU_PM_EXIT: if (__this_cpu_read(kvm_arm_hardware_enabled)) /* The hardware was enabled before suspend. */