KVM: Count the number of dirty pages for dirty logging
Needed for the next patch which uses this number to decide how to write
protect a slot.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 4c5b9a2..af5c988 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -625,6 +625,7 @@
return -ENOMEM;
memslot->dirty_bitmap_head = memslot->dirty_bitmap;
+ memslot->nr_dirty_pages = 0;
return 0;
}
#endif /* !CONFIG_S390 */
@@ -1491,7 +1492,8 @@
if (memslot && memslot->dirty_bitmap) {
unsigned long rel_gfn = gfn - memslot->base_gfn;
- __set_bit_le(rel_gfn, memslot->dirty_bitmap);
+ if (!__test_and_set_bit_le(rel_gfn, memslot->dirty_bitmap))
+ memslot->nr_dirty_pages++;
}
}