[PATCH 2/2] kvm: Fix loop of clear dirty with off-by-one

[Peter Xu <peterx@redhat.com>]

Just imaging the case where num_pages < BITS_PER_LONG, then the loop
will be skipped while it shouldn't.

Signed-off-by: Peter Xu <peterx@redhat.com>
---
 virt/kvm/kvm_main.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index ad39c57de82d..15601a19a87a 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1264,8 +1264,8 @@ int kvm_clear_dirty_log_protect(struct kvm *kvm,
 		return -EFAULT;
 
 	spin_lock(&kvm->mmu_lock);
-	for (offset = log->first_page,
-	     i = offset / BITS_PER_LONG, n = log->num_pages / BITS_PER_LONG; n--;
+	for (offset = log->first_page, i = offset / BITS_PER_LONG,
+		 n = (log->num_pages / BITS_PER_LONG + 1); n--;
 	     i++, offset += BITS_PER_LONG) {
 		unsigned long mask = *dirty_bitmap_buffer++;
 		atomic_long_t *p = (atomic_long_t *) &dirty_bitmap[i];
-- 
2.17.1