On 12.02.20 13:39, Cornelia Huck wrote:
[...]
>> + */
>> + return 0;
>
> Given that this function now always returns 0, we basically get a
> completely useless roundtrip into the kernel when userspace is trying
> to setup the mappings.
>
> Can we define a new IO_ADAPTER_MAPPING_NOT_NEEDED or so capability that
> userspace can check?
Nack. This is one system call per initial indicator ccw. This is so seldom
and cheap that I do not see a point in optimizing this.
> This change in behaviour probably wants a change in the documentation
> as well.
Yep.
[...]
>> @@ -2951,12 +2900,15 @@ int kvm_set_routing_entry(struct kvm *kvm,
>> const struct kvm_irq_routing_entry *ue)
>> {
>> int ret;
>> + u64 uaddr;
>>
>> switch (ue->type) {
>> case KVM_IRQ_ROUTING_S390_ADAPTER:
>> e->set = set_adapter_int;
>> - e->adapter.summary_addr = ue->u.adapter.summary_addr;
>> - e->adapter.ind_addr = ue->u.adapter.ind_addr;
>> + uaddr = gmap_translate(kvm->arch.gmap, ue->u.adapter.summary_addr);
>
> Can gmap_translate() return -EFAULT here? The code above only seems to
> check for 0... do we want to return an error here?
Yes.
>
>> + e->adapter.summary_addr = uaddr;
>> + uaddr = gmap_translate(kvm->arch.gmap, ue->u.adapter.ind_addr);
>> + e->adapter.ind_addr = uaddr;
>> e->adapter.summary_offset = ue->u.adapter.summary_offset;
>> e->adapter.ind_offset = ue->u.adapter.ind_offset;
>> e->adapter.adapter_id = ue->u.adapter.adapter_id;
>
