KVM: cleanup (physical) CPU hotplug

Remove the useless argument, and do not do anything if there are no
VMs running at the time of the hotplug.

Cc: kvm@vger.kernel.org
Cc: gleb@redhat.com
Cc: jan.kiszka@siemens.com
Reviewed-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 8 insertions, 9 deletions

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 979bff485fb0..426051d66173 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -2681,10 +2681,11 @@ static void hardware_enable_nolock(void *junk)
         }
 }
 
-static void hardware_enable(void *junk)
+static void hardware_enable(void)
 {
         raw_spin_lock(&kvm_lock);
-        hardware_enable_nolock(junk);
+        if (kvm_usage_count)
+                hardware_enable_nolock(NULL);
         raw_spin_unlock(&kvm_lock);
 }
 
@@ -2698,10 +2699,11 @@ static void hardware_disable_nolock(void *junk)
         kvm_arch_hardware_disable(NULL);
 }
 
-static void hardware_disable(void *junk)
+static void hardware_disable(void)
 {
         raw_spin_lock(&kvm_lock);
-        hardware_disable_nolock(junk);
+        if (kvm_usage_count)
+                hardware_disable_nolock(NULL);
         raw_spin_unlock(&kvm_lock);
 }
 
@@ -2748,20 +2750,17 @@ static int kvm_cpu_hotplug(struct notifier_block *notifier, unsigned long val,
 {
         int cpu = (long)v;
 
-        if (!kvm_usage_count)
-                return NOTIFY_OK;
-
         val &= ~CPU_TASKS_FROZEN;
         switch (val) {
         case CPU_DYING:
                 printk(KERN_INFO "kvm: disabling virtualization on CPU%d\n",
                        cpu);
-                hardware_disable(NULL);
+                hardware_disable();
                 break;
         case CPU_STARTING:
                 printk(KERN_INFO "kvm: enabling virtualization on CPU%d\n",
                        cpu);
-                hardware_enable(NULL);
+                hardware_enable();
                 break;
         }
         return NOTIFY_OK;