kvm: warn on more invariant breakage
Modifying a non-existent slot is not allowed. Also check that the
first loop doesn't move a deleted slot beyond the used part of
the mslots array.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 050974c..1cc6e2e 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -671,6 +671,7 @@
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--;
@@ -704,7 +705,8 @@
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;