diff options
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/powerpc/include/asm/smp.h | 8 | ||||
| -rw-r--r-- | arch/powerpc/kernel/smp.c | 46 | ||||
| -rw-r--r-- | arch/powerpc/kvm/book3s_hv.c | 12 |
3 files changed, 64 insertions, 2 deletions
diff --git a/arch/powerpc/include/asm/smp.h b/arch/powerpc/include/asm/smp.h index ebc24dc5b1a..b625a1a9ad1 100644 --- a/arch/powerpc/include/asm/smp.h +++ b/arch/powerpc/include/asm/smp.h @@ -66,6 +66,14 @@ void generic_cpu_die(unsigned int cpu); void generic_mach_cpu_die(void); void generic_set_cpu_dead(unsigned int cpu); int generic_check_cpu_restart(unsigned int cpu); + +extern void inhibit_secondary_onlining(void); +extern void uninhibit_secondary_onlining(void); + +#else /* HOTPLUG_CPU */ +static inline void inhibit_secondary_onlining(void) {} +static inline void uninhibit_secondary_onlining(void) {} + #endif #ifdef CONFIG_PPC64 diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c index 8d4214afc21..c4f420c5fc1 100644 --- a/arch/powerpc/kernel/smp.c +++ b/arch/powerpc/kernel/smp.c @@ -417,6 +417,45 @@ int generic_check_cpu_restart(unsigned int cpu) { return per_cpu(cpu_state, cpu) == CPU_UP_PREPARE; } + +static atomic_t secondary_inhibit_count; + +/* + * Don't allow secondary CPU threads to come online + */ +void inhibit_secondary_onlining(void) +{ + /* + * This makes secondary_inhibit_count stable during cpu + * online/offline operations. + */ + get_online_cpus(); + + atomic_inc(&secondary_inhibit_count); + put_online_cpus(); +} +EXPORT_SYMBOL_GPL(inhibit_secondary_onlining); + +/* + * Allow secondary CPU threads to come online again + */ +void uninhibit_secondary_onlining(void) +{ + get_online_cpus(); + atomic_dec(&secondary_inhibit_count); + put_online_cpus(); +} +EXPORT_SYMBOL_GPL(uninhibit_secondary_onlining); + +static int secondaries_inhibited(void) +{ + return atomic_read(&secondary_inhibit_count); +} + +#else /* HOTPLUG_CPU */ + +#define secondaries_inhibited() 0 + #endif static void cpu_idle_thread_init(unsigned int cpu, struct task_struct *idle) @@ -435,6 +474,13 @@ int __cpuinit __cpu_up(unsigned int cpu, struct task_struct *tidle) { int rc, c; + /* + * Don't allow secondary threads to come online if inhibited + */ + if (threads_per_core > 1 && secondaries_inhibited() && + cpu % threads_per_core != 0) + return -EBUSY; + if (smp_ops == NULL || (smp_ops->cpu_bootable && !smp_ops->cpu_bootable(cpu))) return -EINVAL; diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c index 9a15da76e56..c5ddf048e19 100644 --- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -47,6 +47,7 @@ #include <asm/page.h> #include <asm/hvcall.h> #include <asm/switch_to.h> +#include <asm/smp.h> #include <linux/gfp.h> #include <linux/vmalloc.h> #include <linux/highmem.h> @@ -1016,8 +1017,6 @@ static int kvmppc_run_core(struct kvmppc_vcore *vc) /* * Make sure we are running on thread 0, and that * secondary threads are offline. - * XXX we should also block attempts to bring any - * secondary threads online. */ if (threads_per_core > 1 && !on_primary_thread()) { list_for_each_entry(vcpu, &vc->runnable_threads, arch.run_list) @@ -1730,11 +1729,20 @@ int kvmppc_core_init_vm(struct kvm *kvm) kvm->arch.using_mmu_notifiers = !!cpu_has_feature(CPU_FTR_ARCH_206); spin_lock_init(&kvm->arch.slot_phys_lock); + + /* + * Don't allow secondary CPU threads to come online + * while any KVM VMs exist. + */ + inhibit_secondary_onlining(); + return 0; } void kvmppc_core_destroy_vm(struct kvm *kvm) { + uninhibit_secondary_onlining(); + if (kvm->arch.rma) { kvm_release_rma(kvm->arch.rma); kvm->arch.rma = NULL; |