KVM: Fix user memslot overlap check
Prior to memory slot sorting this loop compared all of the user memory
slots for overlap with new entries. With memory slot sorting, we're
just checking some number of entries in the array that may or may not
be user slots. Instead, walk all the slots with kvm_for_each_memslot,
which has the added benefit of terminating early when we hit the first
empty slot, and skip comparison to private slots.
Cc: stable@vger.kernel.org
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index e6cfd43..1cd693a 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -714,8 +714,7 @@
int r;
gfn_t base_gfn;
unsigned long npages;
- unsigned long i;
- struct kvm_memory_slot *memslot;
+ struct kvm_memory_slot *memslot, *slot;
struct kvm_memory_slot old, new;
struct kvm_memslots *slots, *old_memslots;
@@ -766,13 +765,11 @@
/* Check for overlaps */
r = -EEXIST;
- for (i = 0; i < KVM_MEMORY_SLOTS; ++i) {
- struct kvm_memory_slot *s = &kvm->memslots->memslots[i];
-
- if (s == memslot || !s->npages)
+ kvm_for_each_memslot(slot, kvm->memslots) {
+ if (slot->id >= KVM_MEMORY_SLOTS || slot == memslot)
continue;
- if (!((base_gfn + npages <= s->base_gfn) ||
- (base_gfn >= s->base_gfn + s->npages)))
+ if (!((base_gfn + npages <= slot->base_gfn) ||
+ (base_gfn >= slot->base_gfn + slot->npages)))
goto out_free;
}