vdpa_sim: implement get_iova_range()

This implements a sample get_iova_range() for the simulator which
advertise [0, ULLONG_MAX] as the valid range.
Signed-off-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20201023090043.14430-4-jasowang@redhat.comSigned-off-by: Michael S. Tsirkin <mst@redhat.com>

drivers/vdpa/vdpa_sim/vdpa_sim.c

@@ -574,6 +574,16 @@ static u32 vdpasim_get_generation(struct vdpa_device *vdpa)
 	return vdpasim->generation;
 }
 
+static struct vdpa_iova_range vdpasim_get_iova_range(struct vdpa_device *vdpa)
+{
+	struct vdpa_iova_range range = {
+		.first = 0ULL,
+		.last = ULLONG_MAX,
+	};
+
+	return range;
+}
+
 static int vdpasim_set_map(struct vdpa_device *vdpa,
 			   struct vhost_iotlb *iotlb)
 {
@@ -657,6 +667,7 @@ static const struct vdpa_config_ops vdpasim_net_config_ops = {
 	.get_config             = vdpasim_get_config,
 	.set_config             = vdpasim_set_config,
 	.get_generation         = vdpasim_get_generation,
+	.get_iova_range         = vdpasim_get_iova_range,
 	.dma_map                = vdpasim_dma_map,
 	.dma_unmap              = vdpasim_dma_unmap,
 	.free                   = vdpasim_free,
@@ -683,6 +694,7 @@ static const struct vdpa_config_ops vdpasim_net_batch_config_ops = {
 	.get_config             = vdpasim_get_config,
 	.set_config             = vdpasim_set_config,
 	.get_generation         = vdpasim_get_generation,
+	.get_iova_range         = vdpasim_get_iova_range,
 	.set_map                = vdpasim_set_map,
 	.free                   = vdpasim_free,
 };