libqos: access VIRTIO 1.0 vring in little-endian

VIRTIO 1.0 uses little-endian for the vring.  Legacy VIRTIO uses guest
endianness.  Adjust the code to handle both.

Note that qvirtio_readq() is not defined because it has no users.  All
the other accessors are really needed.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20191023100425.12168-10-stefanha@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
diff --git a/tests/libqos/virtio-pci.c b/tests/libqos/virtio-pci.c
index 1b6b760..7ecf5d0 100644
--- a/tests/libqos/virtio-pci.c
+++ b/tests/libqos/virtio-pci.c
@@ -217,6 +217,7 @@
     feat = qvirtio_pci_get_guest_features(d);
 
     qvirtio_pci_queue_select(d, index);
+    vqpci->vq.vdev = d;
     vqpci->vq.index = index;
     vqpci->vq.size = qvirtio_pci_get_queue_size(d);
     vqpci->vq.free_head = 0;