Defer setting the reference count, kvm->users_count, until the VM is guaranteed to be created, so that the reference count need not be cleared on the error path. Suggested-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx> Signed-off-by: Jim Mattson <jmattson@xxxxxxxxxx> Reviewed-by: Junaid Shahid <junaids@xxxxxxxxxx> --- virt/kvm/kvm_main.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index fd68fbe0a75d2..525e0dbc623f9 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -640,7 +640,6 @@ static struct kvm *kvm_create_vm(unsigned long type) mutex_init(&kvm->lock); mutex_init(&kvm->irq_lock); mutex_init(&kvm->slots_lock); - refcount_set(&kvm->users_count, 1); INIT_LIST_HEAD(&kvm->devices); r = kvm_arch_init_vm(kvm, type); @@ -682,6 +681,12 @@ static struct kvm *kvm_create_vm(unsigned long type) if (r) goto out_err; + /* + * kvm_get_kvm() isn't legal while the vm is being created + * (e.g. in kvm_arch_init_vm). + */ + refcount_set(&kvm->users_count, 1); + mutex_lock(&kvm_lock); list_add(&kvm->vm_list, &vm_list); mutex_unlock(&kvm_lock); @@ -697,7 +702,6 @@ static struct kvm *kvm_create_vm(unsigned long type) out_err_no_srcu: hardware_disable_all(); out_err_no_disable: - refcount_set(&kvm->users_count, 0); for (i = 0; i < KVM_NR_BUSES; i++) kfree(kvm_get_bus(kvm, i)); for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) -- 2.24.0.rc0.303.g954a862665-goog
