diff options
Diffstat (limited to 'virt/kvm/kvm_main.c')
| -rw-r--r-- | virt/kvm/kvm_main.c | 26 |
1 files changed, 20 insertions, 6 deletions
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index f5283438ee05..1cc6e2e19982 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -671,6 +671,7 @@ static void update_memslots(struct kvm_memslots *slots, WARN_ON(mslots[i].id != id); if (!new->npages) { + WARN_ON(!mslots[i].npages); new->base_gfn = 0; if (mslots[i].npages) slots->used_slots--; @@ -687,12 +688,25 @@ static void update_memslots(struct kvm_memslots *slots, slots->id_to_index[mslots[i].id] = i; i++; } - while (i > 0 && - new->base_gfn > mslots[i - 1].base_gfn) { - mslots[i] = mslots[i - 1]; - slots->id_to_index[mslots[i].id] = i; - i--; - } + + /* + * The ">=" is needed when creating a slot with base_gfn == 0, + * so that it moves before all those with base_gfn == npages == 0. + * + * On the other hand, if new->npages is zero, the above loop has + * already left i pointing to the beginning of the empty part of + * mslots, and the ">=" would move the hole backwards in this + * case---which is wrong. So skip the loop when deleting a slot. + */ + if (new->npages) { + while (i > 0 && + new->base_gfn >= mslots[i - 1].base_gfn) { + mslots[i] = mslots[i - 1]; + slots->id_to_index[mslots[i].id] = i; + i--; + } + } else + WARN_ON_ONCE(i != slots->used_slots); mslots[i] = *new; slots->id_to_index[mslots[i].id] = i; |