From: Thomas Gleixner Install the callbacks via the state machine. The core won't invoke the callbacks on already online CPUs. Signed-off-by: Thomas Gleixner Reviewed-by: Sebastian Andrzej Siewior Acked-by: Paolo Bonzini Cc: Gleb Natapov Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Radim Krcmar Cc: kvm@vger.kernel.org Signed-off-by: Anna-Maria Gleixner --- include/linux/cpuhotplug.h | 1 + virt/kvm/kvm_main.c | 32 ++++++++------------------------ 2 files changed, 9 insertions(+), 24 deletions(-) diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h index 365d615..1d71f38 100644 --- a/include/linux/cpuhotplug.h +++ b/include/linux/cpuhotplug.h @@ -37,6 +37,7 @@ enum cpuhp_state { CPUHP_AP_PERF_XTENSA_STARTING, CPUHP_AP_ARM_VFP_STARTING, CPUHP_AP_PERF_ARM_STARTING, + CPUHP_AP_KVM_STARTING, CPUHP_AP_NOTIFY_STARTING, CPUHP_AP_ONLINE, CPUHP_TEARDOWN_CPU, diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 48bd520..c1d6cf5 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -3144,12 +3144,13 @@ static void hardware_enable_nolock(void *junk) } } -static void hardware_enable(void) +static int kvm_starting_cpu(unsigned int cpu) { raw_spin_lock(&kvm_count_lock); if (kvm_usage_count) hardware_enable_nolock(NULL); raw_spin_unlock(&kvm_count_lock); + return 0; } static void hardware_disable_nolock(void *junk) @@ -3162,12 +3163,13 @@ static void hardware_disable_nolock(void *junk) kvm_arch_hardware_disable(); } -static void hardware_disable(void) +static int kvm_dying_cpu(unsigned int cpu) { raw_spin_lock(&kvm_count_lock); if (kvm_usage_count) hardware_disable_nolock(NULL); raw_spin_unlock(&kvm_count_lock); + return 0; } static void hardware_disable_all_nolock(void) @@ -3208,21 +3210,6 @@ static int hardware_enable_all(void) return r; } -static int kvm_cpu_hotplug(struct notifier_block *notifier, unsigned long val, - void *v) -{ - val &= ~CPU_TASKS_FROZEN; - switch (val) { - case CPU_DYING: - hardware_disable(); - break; - case CPU_STARTING: - hardware_enable(); - break; - } - return NOTIFY_OK; -} - static int kvm_reboot(struct notifier_block *notifier, unsigned long val, void *v) { @@ -3489,10 +3476,6 @@ int kvm_io_bus_unregister_dev(struct kvm *kvm, enum kvm_bus bus_idx, return r; } -static struct notifier_block kvm_cpu_notifier = { - .notifier_call = kvm_cpu_hotplug, -}; - static int kvm_debugfs_open(struct inode *inode, struct file *file, int (*get)(void *, u64 *), int (*set)(void *, u64), const char *fmt) @@ -3743,7 +3726,8 @@ int kvm_init(void *opaque, unsigned vcpu_size, unsigned vcpu_align, goto out_free_1; } - r = register_cpu_notifier(&kvm_cpu_notifier); + r = cpuhp_setup_state_nocalls(CPUHP_AP_KVM_STARTING, "AP_KVM_STARTING", + kvm_starting_cpu, kvm_dying_cpu); if (r) goto out_free_2; register_reboot_notifier(&kvm_reboot_notifier); @@ -3797,7 +3781,7 @@ out_free: kmem_cache_destroy(kvm_vcpu_cache); out_free_3: unregister_reboot_notifier(&kvm_reboot_notifier); - unregister_cpu_notifier(&kvm_cpu_notifier); + cpuhp_remove_state_nocalls(CPUHP_AP_KVM_STARTING); out_free_2: out_free_1: kvm_arch_hardware_unsetup(); @@ -3820,7 +3804,7 @@ void kvm_exit(void) kvm_async_pf_deinit(); unregister_syscore_ops(&kvm_syscore_ops); unregister_reboot_notifier(&kvm_reboot_notifier); - unregister_cpu_notifier(&kvm_cpu_notifier); + cpuhp_remove_state_nocalls(CPUHP_AP_KVM_STARTING); on_each_cpu(hardware_disable_nolock, NULL, 1); kvm_arch_hardware_unsetup(); kvm_arch_exit(); -- 2.8.1