From: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
Date: Mon, 6 Dec 2021 19:54:26 +0000 (+0100)
Subject: KVM: Move WARN on invalid memslot index to update_memslots()
X-Git-Tag: kvm-5.17-2~203
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=1e8617d37fc36407f9fce9c08ef8d254613c00de;p=users%2Fdwmw2%2Flinux.git

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 6ca076ae64a28..a60d09beef617 100644
--- 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.