net/virtio-user: simplify device features preparation

Get rid of the duplicated code in device features preparation
which looks awful.

Signed-off-by: Tiwei Bie <tiwei.bie@intel.com>
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>

diff --git a/drivers/net/virtio/virtio_user/virtio_user_dev.c b/drivers/net/virtio/virtio_user/virtio_user_dev.c
index ff1c203..20816c9 100644 (file)
--- a/drivers/net/virtio/virtio_user/virtio_user_dev.c
+++ b/drivers/net/virtio/virtio_user/virtio_user_dev.c
@@ -422,7 +422,7 @@ virtio_user_dev_init(struct virtio_user_dev *dev, char *path, int queues,
        dev->queue_size = queue_size;
        dev->mac_specified = 0;
        dev->frontend_features = 0;
-       dev->unsupported_features = 0;
+       dev->unsupported_features = ~VIRTIO_USER_SUPPORTED_FEATURES;
        parse_mac(dev, mac);
 
        if (*ifname) {
@@ -458,22 +458,16 @@ virtio_user_dev_init(struct virtio_user_dev *dev, char *path, int queues,
                dev->device_features = VIRTIO_USER_SUPPORTED_FEATURES;
        }
 
-       if (!mrg_rxbuf) {
-               dev->device_features &= ~(1ull << VIRTIO_NET_F_MRG_RXBUF);
+       if (!mrg_rxbuf)
                dev->unsupported_features |= (1ull << VIRTIO_NET_F_MRG_RXBUF);
-       }
 
-       if (!in_order) {
-               dev->device_features &= ~(1ull << VIRTIO_F_IN_ORDER);
+       if (!in_order)
                dev->unsupported_features |= (1ull << VIRTIO_F_IN_ORDER);
-       }
 
-       if (dev->mac_specified) {
+       if (dev->mac_specified)
                dev->frontend_features |= (1ull << VIRTIO_NET_F_MAC);
-       } else {
-               dev->device_features &= ~(1ull << VIRTIO_NET_F_MAC);
+       else
                dev->unsupported_features |= (1ull << VIRTIO_NET_F_MAC);
-       }
 
        if (cq) {
                /* device does not really need to know anything about CQ,
@@ -481,14 +475,8 @@ virtio_user_dev_init(struct virtio_user_dev *dev, char *path, int queues,
                 */
                dev->frontend_features |= (1ull << VIRTIO_NET_F_CTRL_VQ);
        } else {
-               dev->device_features &= ~(1ull << VIRTIO_NET_F_CTRL_VQ);
-               /* Also disable features depends on VIRTIO_NET_F_CTRL_VQ */
-               dev->device_features &= ~(1ull << VIRTIO_NET_F_CTRL_RX);
-               dev->device_features &= ~(1ull << VIRTIO_NET_F_CTRL_VLAN);
-               dev->device_features &= ~(1ull << VIRTIO_NET_F_GUEST_ANNOUNCE);
-               dev->device_features &= ~(1ull << VIRTIO_NET_F_MQ);
-               dev->device_features &= ~(1ull << VIRTIO_NET_F_CTRL_MAC_ADDR);
                dev->unsupported_features |= (1ull << VIRTIO_NET_F_CTRL_VQ);
+               /* Also disable features that depend on VIRTIO_NET_F_CTRL_VQ */
                dev->unsupported_features |= (1ull << VIRTIO_NET_F_CTRL_RX);
                dev->unsupported_features |= (1ull << VIRTIO_NET_F_CTRL_VLAN);
                dev->unsupported_features |=
@@ -502,9 +490,12 @@ virtio_user_dev_init(struct virtio_user_dev *dev, char *path, int queues,
        if (is_vhost_user_by_type(dev->path))
                dev->frontend_features |= (1ull << VIRTIO_NET_F_STATUS);
 
+       /*
+        * Device features =
+        *     (frontend_features | backend_features) & ~unsupported_features;
+        */
        dev->device_features |= dev->frontend_features;
-       dev->device_features &= VIRTIO_USER_SUPPORTED_FEATURES;
-       dev->unsupported_features |= ~VIRTIO_USER_SUPPORTED_FEATURES;
+       dev->device_features &= ~dev->unsupported_features;
 
        if (rte_mem_event_callback_register(VIRTIO_USER_MEM_EVENT_CLB_NAME,
                                virtio_user_mem_event_cb, dev)) {