Without this patch, kvm cannot start a guest when cpuidle is enabled if the hardware does not retain cpu state (EL2) in idle state.
This patch re-initailizes EL2 state at CPU_PM_EXIT by calling kvm_arch_hardware_enable() if and only if kvm has been initialized before CPU_PM_ENTER, that is, if any vcpus have been created. Signed-off-by: AKASHI Takahiro <[email protected]> --- arch/arm/kvm/arm.c | 25 +++++++++++++++++++++---- 1 file changed, 21 insertions(+), 4 deletions(-) diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c index 0871809..fbff638 100644 --- a/arch/arm/kvm/arm.c +++ b/arch/arm/kvm/arm.c @@ -60,6 +60,8 @@ static atomic64_t kvm_vmid_gen = ATOMIC64_INIT(1); static u8 kvm_next_vmid; static DEFINE_SPINLOCK(kvm_vmid_lock); +static DEFINE_PER_CPU(unsigned char, kvm_arm_hardware_enabled); + static void kvm_arm_set_running_vcpu(struct kvm_vcpu *vcpu) { BUG_ON(preemptible()); @@ -955,12 +957,27 @@ static int hyp_init_cpu_pm_notifier(struct notifier_block *self, unsigned long cmd, void *v) { - if (cmd == CPU_PM_EXIT && kvm_arm_get_running_vcpu()) { - kvm_arch_hardware_enable(); + switch (cmd) { + case CPU_PM_ENTER: + if (__hyp_get_vectors() != hyp_default_vectors) + __this_cpu_write(kvm_arm_hardware_enabled, 1); + else + __this_cpu_write(kvm_arm_hardware_enabled, 0); + /* + * don't call kvm_arch_hardware_disable() in case of + * CPU_PM_ENTER because it does't actually save any state. + */ + + return NOTIFY_OK; + case CPU_PM_EXIT: + if (__this_cpu_read(kvm_arm_hardware_enabled)) + kvm_arch_hardware_enable(); + return NOTIFY_OK; - } - return NOTIFY_DONE; + default: + return NOTIFY_DONE; + } } static struct notifier_block hyp_init_cpu_pm_nb = { -- 1.7.9.5 _______________________________________________ kexec mailing list [email protected] http://lists.infradead.org/mailman/listinfo/kexec
