vdpa_sim_net: Add the support of set mac address

Add the function to support setting the MAC address.
For vdpa_sim_net, the driver will write the MAC address
to the config space, and other devices can implement
their own functions to support this.
Signed-off-by: Cindy Lu <lulu@redhat.com>
Message-Id: <20240731031653.1047692-3-lulu@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>

drivers/vdpa/vdpa_sim/vdpa_sim_net.c

@@ -414,6 +414,24 @@ static void vdpasim_net_get_config(struct vdpasim *vdpasim, void *config)
 	net_config->status = cpu_to_vdpasim16(vdpasim, VIRTIO_NET_S_LINK_UP);
 }
 
+static int vdpasim_net_set_attr(struct vdpa_mgmt_dev *mdev, struct vdpa_device *dev,
+				const struct vdpa_dev_set_config *config)
+{
+	struct vdpasim *vdpasim = container_of(dev, struct vdpasim, vdpa);
+	struct virtio_net_config *vio_config = vdpasim->config;
+
+	mutex_lock(&vdpasim->mutex);
+
+	if (config->mask & (1 << VDPA_ATTR_DEV_NET_CFG_MACADDR)) {
+		ether_addr_copy(vio_config->mac, config->net.mac);
+		mutex_unlock(&vdpasim->mutex);
+		return 0;
+	}
+
+	mutex_unlock(&vdpasim->mutex);
+	return -EOPNOTSUPP;
+}
+
 static void vdpasim_net_setup_config(struct vdpasim *vdpasim,
 				     const struct vdpa_dev_set_config *config)
 {
@@ -510,7 +528,8 @@ static void vdpasim_net_dev_del(struct vdpa_mgmt_dev *mdev,
 
 static const struct vdpa_mgmtdev_ops vdpasim_net_mgmtdev_ops = {
 	.dev_add = vdpasim_net_dev_add,
-	.dev_del = vdpasim_net_dev_del
+	.dev_del = vdpasim_net_dev_del,
+	.dev_set_attr = vdpasim_net_set_attr
 };
 
 static struct virtio_device_id id_table[] = {