virtio-net: Move DEFINE_VIRTIO_NET_FEATURES to virtio-net

So far virtio-net-device can't expose host features to guest while
using virtio-mmio because it doesn't set DEFINE_VIRTIO_NET_FEATURES on
backend or transport. So the performance is low.

The host features belong to the backend while virtio-net-pci,
virtio-net-s390 and virtio-net-ccw set the DEFINE_VIRTIO_NET_FEATURES
on transports. But they already have the ability to forward property
accesses to the backend child. So if we move the host features to
backends, it doesn't break the backwards compatibility for them and
make host features work while using virtio-mmio.

Here we move DEFINE_VIRTIO_NET_FEATURES to the backend virtio-net. The
transports just sync the host features from backend. Meanwhile move
virtio_net_set_config_size to virtio-net to make sure the config size
is correct and don't expose it.
Signed-off-by: NShannon Zhao <zhaoshenglong@huawei.com>
Signed-off-by: NShannon Zhao <shannon.zhao@linaro.org>
Reviewed-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
Reviewed-by: NPeter Maydell <peter.maydell@linaro.org>

hw/net/virtio-net.c

@@ -446,6 +446,9 @@ static uint32_t virtio_net_get_features(VirtIODevice *vdev, uint32_t features)
     VirtIONet *n = VIRTIO_NET(vdev);
     NetClientState *nc = qemu_get_queue(n->nic);
 
+    /* Firstly sync all virtio-net possible supported features */
+    features |= n->host_features;
+
     virtio_add_feature(&features, VIRTIO_NET_F_MAC);
 
     if (!peer_has_vnet_hdr(n)) {
@@ -1552,7 +1555,7 @@ static void virtio_net_guest_notifier_mask(VirtIODevice *vdev, int idx,
                              vdev, idx, mask);
 }
 
-void virtio_net_set_config_size(VirtIONet *n, uint32_t host_features)
+static void virtio_net_set_config_size(VirtIONet *n, uint32_t host_features)
 {
     int i, config_size = 0;
     virtio_add_feature(&host_features, VIRTIO_NET_F_MAC);
@@ -1585,6 +1588,7 @@ static void virtio_net_device_realize(DeviceState *dev, Error **errp)
     NetClientState *nc;
     int i;
 
+    virtio_net_set_config_size(n, n->host_features);
     virtio_init(vdev, "virtio-net", VIRTIO_ID_NET, n->config_size);
 
     n->max_queues = MAX(n->nic_conf.peers.queues, 1);
@@ -1721,6 +1725,7 @@ static void virtio_net_instance_init(Object *obj)
 }
 
 static Property virtio_net_properties[] = {
+    DEFINE_VIRTIO_NET_FEATURES(VirtIONet, host_features),
     DEFINE_NIC_PROPERTIES(VirtIONet, nic_conf),
     DEFINE_PROP_UINT32("x-txtimer", VirtIONet, net_conf.txtimer,
                                                TX_TIMER_INTERVAL),

hw/s390x/s390-virtio-bus.c

@@ -145,7 +145,6 @@ static void s390_virtio_net_realize(VirtIOS390Device *s390_dev, Error **errp)
     DeviceState *vdev = DEVICE(&dev->vdev);
     Error *err = NULL;
 
-    virtio_net_set_config_size(&dev->vdev, s390_dev->host_features);
     virtio_net_set_netclient_name(&dev->vdev, qdev->id,
                                   object_get_typename(OBJECT(qdev)));
     qdev_set_parent_bus(vdev, BUS(&s390_dev->bus));
@@ -508,7 +507,6 @@ static unsigned virtio_s390_get_features(DeviceState *d)
 
 static Property s390_virtio_net_properties[] = {
     DEFINE_VIRTIO_COMMON_FEATURES(VirtIOS390Device, host_features),
-    DEFINE_VIRTIO_NET_FEATURES(VirtIOS390Device, host_features),
     DEFINE_PROP_END_OF_LIST(),
 };
 

hw/s390x/virtio-ccw.c

@@ -779,7 +779,6 @@ static void virtio_ccw_net_realize(VirtioCcwDevice *ccw_dev, Error **errp)
     DeviceState *vdev = DEVICE(&dev->vdev);
     Error *err = NULL;
 
-    virtio_net_set_config_size(&dev->vdev, ccw_dev->host_features[0]);
     virtio_net_set_netclient_name(&dev->vdev, qdev->id,
                                   object_get_typename(OBJECT(qdev)));
     qdev_set_parent_bus(vdev, BUS(&ccw_dev->bus));
@@ -1403,7 +1402,6 @@ static int virtio_ccw_load_config(DeviceState *d, QEMUFile *f)
 
 static Property virtio_ccw_net_properties[] = {
     DEFINE_PROP_STRING("devno", VirtioCcwDevice, bus_id),
-    DEFINE_VIRTIO_NET_FEATURES(VirtioCcwDevice, host_features[0]),
     DEFINE_PROP_BIT("ioeventfd", VirtioCcwDevice, flags,
                     VIRTIO_CCW_FLAG_USE_IOEVENTFD_BIT, true),
     DEFINE_PROP_END_OF_LIST(),

hw/virtio/virtio-pci.c

@@ -1369,7 +1369,6 @@ static Property virtio_net_properties[] = {
     DEFINE_PROP_BIT("ioeventfd", VirtIOPCIProxy, flags,
                     VIRTIO_PCI_FLAG_USE_IOEVENTFD_BIT, false),
     DEFINE_PROP_UINT32("vectors", VirtIOPCIProxy, nvectors, 3),
-    DEFINE_VIRTIO_NET_FEATURES(VirtIOPCIProxy, host_features),
     DEFINE_PROP_END_OF_LIST(),
 };
 
@@ -1379,7 +1378,6 @@ static void virtio_net_pci_realize(VirtIOPCIProxy *vpci_dev, Error **errp)
     VirtIONetPCI *dev = VIRTIO_NET_PCI(vpci_dev);
     DeviceState *vdev = DEVICE(&dev->vdev);
 
-    virtio_net_set_config_size(&dev->vdev, vpci_dev->host_features);
     virtio_net_set_netclient_name(&dev->vdev, qdev->id,
                                   object_get_typename(OBJECT(qdev)));
     qdev_set_parent_bus(vdev, BUS(&vpci_dev->bus));

include/hw/virtio/virtio-net.h

@@ -68,6 +68,7 @@ typedef struct VirtIONet {
     uint32_t has_vnet_hdr;
     size_t host_hdr_len;
     size_t guest_hdr_len;
+    uint32_t host_features;
     uint8_t has_ufo;
     int mergeable_rx_bufs;
     uint8_t promisc;
@@ -137,7 +138,6 @@ typedef struct VirtIONet {
     DEFINE_PROP_INT32("x-txburst", _state, _field.txburst, TX_BURST),          \
     DEFINE_PROP_STRING("tx", _state, _field.tx)
 
-void virtio_net_set_config_size(VirtIONet *n, uint32_t host_features);
 void virtio_net_set_netclient_name(VirtIONet *n, const char *name,
                                    const char *type);