KVM: Move WARN on invalid memslot index to update_memslots()

Since kvm_memslot_move_forward() can theoretically return a negative
memslot index even when kvm_memslot_move_backward() returned a positive one
(and so did not WARN) let's just move the warning to the common code.

Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Message-Id: <eeed890ccb951e7b0dce15bc170eb2661d5b02da.1638817640.git.maciej.szmigiero@oracle.com>

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 6ca076ae64a28f714f0f84342353279474c57065..a60d09beef617013364363abf605dae360e6ab92 100644 (file)
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1322,8 +1322,7 @@ static inline int kvm_memslot_move_backward(struct kvm_memslots *slots,
        struct kvm_memory_slot *mslots = slots->memslots;
        int i;
 
-       if (WARN_ON_ONCE(slots->id_to_index[memslot->id] == -1) ||
-           WARN_ON_ONCE(!slots->used_slots))
+       if (slots->id_to_index[memslot->id] == -1 || !slots->used_slots)
                return -1;
 
        /*
@@ -1427,6 +1426,9 @@ static void update_memslots(struct kvm_memslots *slots,
                        i = kvm_memslot_move_backward(slots, memslot);
                i = kvm_memslot_move_forward(slots, memslot, i);
 
+               if (WARN_ON_ONCE(i < 0))
+                       return;
+
                /*
                 * Copy the memslot to its new position in memslots and update
                 * its index accordingly.