Re: [PATCH 3/4] KVM: Dynamic sized kvm memslots array

[David Hildenbrand <david@redhat.com>]

>>
>> Then, you can remove the parameter from kvm_slots_grow() completely and just call it
>> kvm_slots_double() and simplify a bit:
>>
>> static bool kvm_slots_double(KVMMemoryListener *kml)
>> {
>>      unsigned int i, nr_slots_new, cur = kml->nr_slots_allocated;
>>      KVMSlot *slots;
>>
>>      nr_slots_new = MIN(cur * 2, kvm_state->nr_slots_max);
>>      if (nr_slots_new == kvm_state->nr_slots_max) {
>>          /* We reached the maximum */
>> 	return false;
>>      }
>>
>>      assert(kml->slots);
>>      slots = g_renew(KVMSlot, kml->slots, nr_slots_new);
>>      /*
>>       * g_renew() doesn't initialize extended buffers, however kvm
>>       * memslots require fields to be zero-initialized. E.g. pointers,
>>       * memory_size field, etc.
>>       */
>>      memset(&slots[cur], 0x0, sizeof(slots[0]) * (nr_slots_new - cur));
>>
>>      for (i = cur; i < nr_slots_new; i++) {
>>          slots[i].slot = i;
>>      }
>>
>>      kml->slots = slots;
>>      kml->nr_slots_allocated = nr_slots_new;
>>      trace_kvm_slots_grow(cur, nr_slots_new);
>>
>>      return true;
>> }
> 
> Personally I still think it cleaner to allow setting whatever size.

Why would one need that? If any, at some point we would want to shrink 
or rather "compact".

> 
> We only have one place growing so far, which is pretty trivial to double
> there, IMO.  I'll wait for a second opinion, or let me know if you have
> strong feelings..

I think the simplicity of kvm_slots_double() speaks for itself, but I 
won't fight for it.

-- 
Cheers,

David / dhildenb