diff options
| -rw-r--r-- | include/linux/kvm_host.h | 4 | ||||
| -rw-r--r-- | virt/kvm/kvm_main.c | 17 |
2 files changed, 20 insertions, 1 deletions
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index f4e143621e3..a2ceb51b427 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -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; } diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 41d4b651913..93ed78b015c 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -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; } |