On Thu, 23 Mar 2017 17:20:48 +0100
David Hildenbrand <david@xxxxxxxxxx> wrote:
>
> > As this may set kvm->buses[bus_idx] to NULL, don't you also need to
> > guard for bus == NULL in kvm_io_bus_destroy()? (I looked at the code on
> > kvm/queue.)
>
> very right, so something like this?
>
> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
> index e1be4b4..ef1aa7f 100644
> --- a/virt/kvm/kvm_main.c
> +++ b/virt/kvm/kvm_main.c
> @@ -728,7 +728,8 @@ static void kvm_destroy_vm(struct kvm *kvm)
> spin_unlock(&kvm_lock);
> kvm_free_irq_routing(kvm);
> for (i = 0; i < KVM_NR_BUSES; i++) {
> - kvm_io_bus_destroy(kvm->buses[i]);
> + if (kvm->buses[i])
> + kvm_io_bus_destroy(kvm->buses[i]);
> kvm->buses[i] = NULL;
> }
> kvm_coalesced_mmio_free(kvm);
>
> Thanks!
>
> >
> >> synchronize_srcu_expedited(&kvm->srcu);
> >> kfree(bus);
> >> - return r;
> >> + return;
> >> }
> >
>
>
Either that, or an early exit for bus == NULL in kvm_io_bus_destroy().
(I think the second option is more straightforward.)