[Qemu-devel] [PULL 26/28] virtio-net: Move DEFINE_VIRTIO_NET_FEATURES to virtio-net

["Michael S. Tsirkin" <mst@redhat.com>]

From: Shannon Zhao <shannon.zhao@linaro.org>

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: Shannon Zhao <zhaoshenglong@huawei.com>
Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
---
 include/hw/virtio/virtio-net.h | 2 +-
 hw/net/virtio-net.c            | 7 ++++++-
 hw/s390x/s390-virtio-bus.c     | 2 --
 hw/s390x/virtio-ccw.c          | 2 --
 hw/virtio/virtio-pci.c         | 2 --
 5 files changed, 7 insertions(+), 8 deletions(-)

diff --git a/include/hw/virtio/virtio-net.h b/include/hw/virtio/virtio-net.h
index 4c2fe83..e0dbb41 100644
--- a/include/hw/virtio/virtio-net.h
+++ b/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);
 
diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
index b6fac9c..c23284f 100644
--- a/hw/net/virtio-net.c
+++ b/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),
diff --git a/hw/s390x/s390-virtio-bus.c b/hw/s390x/s390-virtio-bus.c
index 047c963..b893e02 100644
--- a/hw/s390x/s390-virtio-bus.c
+++ b/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(),
 };
 
diff --git a/hw/s390x/virtio-ccw.c b/hw/s390x/virtio-ccw.c
index 0434f56..e6e9f9d 100644
--- a/hw/s390x/virtio-ccw.c
+++ b/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(),
diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
index 5ea4656..07b2a67 100644
--- a/hw/virtio/virtio-pci.c
+++ b/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));
-- 
MST