If we directly cast from int to uint64_t, we will first sign-extend to
an int64_t, which is wrong. We actually want to treat the PFNs like
unsigned values.
As far as I can see, this dates back to the initial virtio-balloon
commit, but wasn't triggered as fairly big guests would be required.
Cc: qemu-stable@nongnu.org
Reported-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20190722134108.22151-2-david@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
ffa207d082