vdpasim: support batch updating

The vDPA simulator support both set_map() and dma_map()/dma_unmap()
operations. But vhost-vdpa can only use one of them. So this patch
introduce a module parameter (batch_mapping) that let vpda_sim to
support only one of those dma operations. The batched mapping via
set_map() is enabled by default.
Signed-off-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20200804162048.22587-6-eli@mellanox.comSigned-off-by: Michael S. Tsirkin <mst@redhat.com>

drivers/vdpa/vdpa_sim/vdpa_sim.c

@@ -34,6 +34,10 @@
 #define DRV_DESC     "vDPA Device Simulator"
 #define DRV_LICENSE  "GPL v2"
 
+static int batch_mapping = 1;
+module_param(batch_mapping, int, 0444);
+MODULE_PARM_DESC(batch_mapping, "Batched mapping 1 -Enable; 0 - Disable");
+
 struct vdpasim_virtqueue {
 	struct vringh vring;
 	struct vringh_kiov iov;
@@ -334,15 +338,21 @@ static const struct dma_map_ops vdpasim_dma_ops = {
 };
 
 static const struct vdpa_config_ops vdpasim_net_config_ops;
+static const struct vdpa_config_ops vdpasim_net_batch_config_ops;
 
 static struct vdpasim *vdpasim_create(void)
 {
+	const struct vdpa_config_ops *ops;
 	struct vdpasim *vdpasim;
 	struct device *dev;
 	int ret = -ENOMEM;
 
-	vdpasim = vdpa_alloc_device(struct vdpasim, vdpa, NULL,
-				    &vdpasim_net_config_ops);
+	if (batch_mapping)
+		ops = &vdpasim_net_batch_config_ops;
+	else
+		ops = &vdpasim_net_config_ops;
+
+	vdpasim = vdpa_alloc_device(struct vdpasim, vdpa, NULL, ops);
 	if (!vdpasim)
 		goto err_alloc;
 
@@ -643,12 +653,36 @@ 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,
-	.set_map                = vdpasim_set_map,
 	.dma_map                = vdpasim_dma_map,
 	.dma_unmap              = vdpasim_dma_unmap,
 	.free                   = vdpasim_free,
 };
 
+static const struct vdpa_config_ops vdpasim_net_batch_config_ops = {
+	.set_vq_address         = vdpasim_set_vq_address,
+	.set_vq_num             = vdpasim_set_vq_num,
+	.kick_vq                = vdpasim_kick_vq,
+	.set_vq_cb              = vdpasim_set_vq_cb,
+	.set_vq_ready           = vdpasim_set_vq_ready,
+	.get_vq_ready           = vdpasim_get_vq_ready,
+	.set_vq_state           = vdpasim_set_vq_state,
+	.get_vq_state           = vdpasim_get_vq_state,
+	.get_vq_align           = vdpasim_get_vq_align,
+	.get_features           = vdpasim_get_features,
+	.set_features           = vdpasim_set_features,
+	.set_config_cb          = vdpasim_set_config_cb,
+	.get_vq_num_max         = vdpasim_get_vq_num_max,
+	.get_device_id          = vdpasim_get_device_id,
+	.get_vendor_id          = vdpasim_get_vendor_id,
+	.get_status             = vdpasim_get_status,
+	.set_status             = vdpasim_set_status,
+	.get_config             = vdpasim_get_config,
+	.set_config             = vdpasim_set_config,
+	.get_generation         = vdpasim_get_generation,
+	.set_map                = vdpasim_set_map,
+	.free                   = vdpasim_free,
+};
+
 static int __init vdpasim_dev_init(void)
 {
 	vdpasim_dev = vdpasim_create();