commit 4fa92fb25ae5a2d79d872ab54df511c831b1f363
author Paolo Bonzini <pbonzini@redhat.com> Tue Sep 10 12:57:17 2013 +0200
committer Paolo Bonzini <pbonzini@redhat.com> Mon Sep 30 09:21:30 2013 +0200
tree e8d25b4fb392cc7ec498346d40a593f2cf5953f2
parent feaf0c7dc473fefa1f263d88788f57e39b4b007e

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>

virt/kvm/kvm_main.c

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 979bff4..426051d 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -2681,10 +2681,11 @@
 	}
 }
 
-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 @@
 	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 @@
 {
 	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;