KVM: add vm refcounting (d39f13b0) · Commits · 戴 / test

include/linux/kvm_host.h

+4 −0

Original line number	Diff line number	Diff line
		@@ -114,6 +114,7 @@ struct kvm {
		struct kvm_io_bus pio_bus;
		struct kvm_vm_stat stat;
		struct kvm_arch arch;
		atomic_t users_count;
		};

		/* The guest did something we don't support. */
		@@ -140,6 +141,9 @@ int kvm_init(void *opaque, unsigned int vcpu_size,
		struct module *module);
		void kvm_exit(void);

		void kvm_get_kvm(struct kvm *kvm);
		void kvm_put_kvm(struct kvm *kvm);

		#define HPA_MSB ((sizeof(hpa_t) * 8) - 1)
		#define HPA_ERR_MASK ((hpa_t)1 << HPA_MSB)
		static inline int is_error_hpa(hpa_t hpa) { return hpa >> HPA_MSB; }

+16 −1

Original line number	Diff line number	Diff line
		@@ -193,6 +193,7 @@ static struct kvm *kvm_create_vm(void)
		mutex_init(&kvm->lock);
		kvm_io_bus_init(&kvm->mmio_bus);
		init_rwsem(&kvm->slots_lock);
		atomic_set(&kvm->users_count, 1);
		spin_lock(&kvm_lock);
		list_add(&kvm->vm_list, &vm_list);
		spin_unlock(&kvm_lock);
		@@ -242,11 +243,25 @@ static void kvm_destroy_vm(struct kvm *kvm)
		mmdrop(mm);
		}

		void kvm_get_kvm(struct kvm *kvm)
		{
		atomic_inc(&kvm->users_count);
		}
		EXPORT_SYMBOL_GPL(kvm_get_kvm);

		void kvm_put_kvm(struct kvm *kvm)
		{
		if (atomic_dec_and_test(&kvm->users_count))
		kvm_destroy_vm(kvm);
		}
		EXPORT_SYMBOL_GPL(kvm_put_kvm);


		static int kvm_vm_release(struct inode inode, struct file filp)
		{
		struct kvm *kvm = filp->private_data;

		kvm_destroy_vm(kvm);
		kvm_put_kvm(kvm);
		return 0;
		}