On 22/08/2018 15:57, Wei Yang wrote:
> update_memslots() is only called by __kvm_set_memory_region(), in which
> "change" is calculated and indicates how to adjust slots->used_slots
>
> * increase by one if it is KVM_MR_CREATE
> * decrease by one if it is KVM_MR_DELETE
> * not change for others
>
> This patch adjusts slots->used_slots in update_memslots() based on "change"
> value instead of re-calculate those states again.
>
> Signed-off-by: Wei Yang <richard.weiyang@xxxxxxxxx>
>
> ---
> v2: use switch on change instead of encode the adjustment in it.
> add warning in case the status is not correct
>
> ---
> virt/kvm/kvm_main.c | 23 ++++++++++++++---------
> 1 file changed, 14 insertions(+), 9 deletions(-)
>
> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
> index 0df592c4f09f..692885c1457f 100644
> --- a/virt/kvm/kvm_main.c
> +++ b/virt/kvm/kvm_main.c
> @@ -802,20 +802,25 @@ static int kvm_create_dirty_bitmap(struct kvm_memory_slot *memslot)
> * sorted array and known changed memslot position.
> */
> static void update_memslots(struct kvm_memslots *slots,
> - struct kvm_memory_slot *new)
> + struct kvm_memory_slot *new,
> + enum kvm_mr_change change)
> {
> int id = new->id;
> int i = slots->id_to_index[id];
> struct kvm_memory_slot *mslots = slots->memslots;
>
> WARN_ON(mslots[i].id != id);
> - if (!new->npages) {
> - WARN_ON(!mslots[i].npages);
> - if (mslots[i].npages)
> - slots->used_slots--;
> - } else {
> - if (!mslots[i].npages)
> - slots->used_slots++;
> + switch (change) {
> + case KVM_MR_CREATE:
> + slots->used_slots++;
> + WARN_ON(mslots[i].npages || !new->npages);
> + break;
> + case KVM_MR_DELETE:
> + slots->used_slots--;
> + WARN_ON(new->npages || !mslots[i].npages);
> + break;
> + default:
> + break;
> }
>
> while (i < KVM_MEM_SLOTS_NUM - 1 &&
> @@ -1051,7 +1056,7 @@ int __kvm_set_memory_region(struct kvm *kvm,
> memset(&new.arch, 0, sizeof(new.arch));
> }
>
> - update_memslots(slots, &new);
> + update_memslots(slots, &new, change);
> old_memslots = install_new_memslots(kvm, as_id, slots);
>
> kvm_arch_commit_memory_region(kvm, mem, &old, &new, change);
>
Queued, thanks.
Paolo
