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virt: Convert kvm hotplug to state machine 

Install the callbacks via the state machine. The core won't invoke the
callbacks on already online CPUs.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Radim Krcmar <rkrcmar@redhat.com>
Cc: kvm@vger.kernel.org
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20160713153335.886159080@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
hifive-unleashed-5.1
Thomas Gleixner 2016-07-13 17:16:37 +00:00 committed by Ingo Molnar
parent 7d88eb695a
commit 8c18b2d2d0
2 changed files with 9 additions and 24 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
include/linux/cpuhotplug.h
View File

@ -36,6 +36,7 @@ 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,

32
virt/kvm/kvm_main.c
View File

@ -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();