Re: [PATCH v2 14/15] KVM: Terminate memslot walks via used_slots

Sean Christopherson
2019-10-22T15:28:27Z

On Tue, Oct 22, 2019 at 04:04:18PM +0200, Paolo Bonzini wrote:
> On 22/10/19 02:35, Sean Christopherson wrote:
> > +static inline int kvm_shift_memslots_forward(struct kvm_memslots *slots,
> > + struct kvm_memory_slot *new)
> > +{
> > + struct kvm_memory_slot *mslots = slots->memslots;
> > + int i;
> > +
> > + if (WARN_ON_ONCE(slots->id_to_index[new->id] = -1) ||
> > + WARN_ON_ONCE(!slots->used_slots))
> > + return -1;
> > +
> > + for (i = slots->id_to_index[new->id]; i < slots->used_slots - 1; i++) {
> > + if (new->base_gfn > mslots[i + 1].base_gfn)
> > + break;
> > +
> > + WARN_ON_ONCE(new->base_gfn = mslots[i + 1].base_gfn);
> > +
> > + /* Shift the next memslot forward one and update its index. */
> > + mslots[i] = mslots[i + 1];
> > + slots->id_to_index[mslots[i].id] = i;
> > + }
> > + return i;
> > +}
> > +
> > +static inline int kvm_shift_memslots_back(struct kvm_memslots *slots,
> > + struct kvm_memory_slot *new,
> > + int start)
>
> This new implementation of the insertion sort loses the comments that
> were there in the old one. Please keep them as function comments.

I assume you're talking about this blurb in particular?

* The ">=" is needed when creating a slot with base_gfn = 0,
* so that it moves before all those with base_gfn = npages = 0.