On 21/03/2016 15:47, Eric Dumazet wrote: > On Mon, 2016-03-21 at 10:24 +0100, Paolo Bonzini wrote: >> kvm_arch_init_vm is now using mmu_lock, causing lockdep to >> complain: > ... >> >> Reported-by: Borislav Petkov <[email protected]> >> Signed-off-by: Paolo Bonzini <[email protected]> >> --- >> virt/kvm/kvm_main.c | 20 ++++++++++---------- >> 1 file changed, 10 insertions(+), 10 deletions(-) >> >> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c >> index 7ba1d10ffed2..cb45b86a1c48 100644 >> --- a/virt/kvm/kvm_main.c >> +++ b/virt/kvm/kvm_main.c >> @@ -536,6 +536,16 @@ static struct kvm *kvm_create_vm(unsigned long type) >> if (!kvm) >> return ERR_PTR(-ENOMEM); >> >> + spin_lock_init(&kvm->mmu_lock); >> + kvm->mm = current->mm; >> + atomic_inc(&kvm->mm->mm_count); > > current->mm->mm_count is incremented here. > >> + kvm_eventfd_init(kvm); >> + mutex_init(&kvm->lock); >> + mutex_init(&kvm->irq_lock); >> + mutex_init(&kvm->slots_lock); >> + atomic_set(&kvm->users_count, 1); >> + INIT_LIST_HEAD(&kvm->devices); >> + >> r = kvm_arch_init_vm(kvm, type); >> if (r) >> goto out_err_no_disable; > > > But out_err_no_disable wont decrement it in case of an error. > > This is not clear to me where the cleanup is done ?
Indeed, a slightly more complex patch is necessary. Will try again, this time not doing this as the first thing in the morning. Paolo >> @@ -568,16 +578,6 @@ static struct kvm *kvm_create_vm(unsigned long type) >> goto out_err; >> } >> >> - spin_lock_init(&kvm->mmu_lock); >> - kvm->mm = current->mm; >> - atomic_inc(&kvm->mm->mm_count); >> - kvm_eventfd_init(kvm); >> - mutex_init(&kvm->lock); >> - mutex_init(&kvm->irq_lock); >> - mutex_init(&kvm->slots_lock); >> - atomic_set(&kvm->users_count, 1); >> - INIT_LIST_HEAD(&kvm->devices); >> - >> r = kvm_init_mmu_notifier(kvm); >> if (r) >> goto out_err; > >
