kvm: destroy emulated devices on VM exit

The hassle of getting refcounting right was greater than the hassle
of keeping a list of devices to destroy on VM exit.

Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>

include/linux/kvm_host.h

@@ -393,6 +393,7 @@ struct kvm {
 	long mmu_notifier_count;
 #endif
 	long tlbs_dirty;
+	struct list_head devices;
 };
 
 #define kvm_err(fmt, ...) \
@@ -1069,8 +1070,8 @@ struct kvm_device_ops;
 struct kvm_device {
 	struct kvm_device_ops *ops;
 	struct kvm *kvm;
-	atomic_t users;
 	void *private;
+	struct list_head vm_node;
 };
 
 /* create, destroy, and name are mandatory */