[Xen-devel] [PoC PATCH] net: convert xen-netfront to hw_features

[MichaÅ MirosÅaw <mirq-linux@xxxxxxxxxxxx>]

This patch converts xen-netfront to hw_features.

It's not tested in any way. The original code for offload setting seems
broken as it resets the features on every netback reconnect.

This will set GSO_ROBUST at device creation time (earlier than connect time).

RX checksum offload is forced on - so advertise as it is.

netdev_update_features() should be called whenever offload conditions change.
This in turn calls ndo_fix_features() and ndo_set_features() to verify them.
I leave this to you as I don't know when or how the notifications get passed.

Signed-off-by: MichaÅ MirosÅaw <mirq-linux@xxxxxxxxxxxx>
---
 drivers/net/xen-netfront.c |   57 +++++++++++++++++--------------------------
 1 files changed, 23 insertions(+), 34 deletions(-)

diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c
index da1f121..c642fd3 100644
--- a/drivers/net/xen-netfront.c
+++ b/drivers/net/xen-netfront.c
@@ -1148,6 +1148,8 @@ static const struct net_device_ops xennet_netdev_ops = {
        .ndo_change_mtu      = xennet_change_mtu,
        .ndo_set_mac_address = eth_mac_addr,
        .ndo_validate_addr   = eth_validate_addr,
+       .ndo_fix_features    = xennet_fix_features,
+       .ndo_set_features    = xennet_set_features,
 };
 
 static struct net_device * __devinit xennet_create_dev(struct xenbus_device 
*dev)
@@ -1209,7 +1211,9 @@ static struct net_device * __devinit 
xennet_create_dev(struct xenbus_device *dev
        netdev->netdev_ops      = &xennet_netdev_ops;
 
        netif_napi_add(netdev, &np->napi, xennet_poll, 64);
-       netdev->features        = NETIF_F_IP_CSUM;
+       netdev->features        = NETIF_F_IP_CSUM | NETIF_F_RXCSUM |
+                                 NETIF_F_GSO_ROBUST;
+       netdev->hw_features     = NETIF_F_IP_CSUM | NETIF_F_SG | NETIF_F_TSO;
 
        SET_ETHTOOL_OPS(netdev, &xennet_ethtool_ops);
        SET_NETDEV_DEV(netdev, &dev->dev);
@@ -1510,52 +1514,40 @@ again:
        return err;
 }
 
-static int xennet_set_sg(struct net_device *dev, u32 data)
+static u32 xennet_fix_features(struct net_device *dev, u32 features)
 {
-       if (data) {
-               struct netfront_info *np = netdev_priv(dev);
-               int val;
+       struct netfront_info *np = netdev_priv(dev);
+       int val;
 
+       if (features & NETIF_F_SG) {
                if (xenbus_scanf(XBT_NIL, np->xbdev->otherend, "feature-sg",
                                 "%d", &val) < 0)
                        val = 0;
+
                if (!val)
-                       return -ENOSYS;
-       } else if (dev->mtu > ETH_DATA_LEN)
-               dev->mtu = ETH_DATA_LEN;
-
-       return ethtool_op_set_sg(dev, data);
-}
-
-static int xennet_set_tso(struct net_device *dev, u32 data)
-{
-       if (data) {
-               struct netfront_info *np = netdev_priv(dev);
-               int val;
+                       features &= ~NETIF_F_SG;
+       }
 
+       if (features & NETIF_F_TSO) {
                if (xenbus_scanf(XBT_NIL, np->xbdev->otherend,
                                 "feature-gso-tcpv4", "%d", &val) < 0)
                        val = 0;
+
                if (!val)
-                       return -ENOSYS;
+                       features &= ~NETIF_F_TSO;
        }
 
-       return ethtool_op_set_tso(dev, data);
+       return features;
 }
 
-static void xennet_set_features(struct net_device *dev)
+static int xennet_set_features(struct net_device *dev, u32 features)
 {
-       /* Turn off all GSO bits except ROBUST. */
-       dev->features &= ~NETIF_F_GSO_MASK;
-       dev->features |= NETIF_F_GSO_ROBUST;
-       xennet_set_sg(dev, 0);
+       if (!(features & NETIF_F_SG) && dev->mtu > ETH_DATA_LEN) {
+               netdev_info(dev, "Reducing MTU because no SG offload");
+               dev->mtu = ETH_DATA_LEN;
+       }
 
-       /* We need checksum offload to enable scatter/gather and TSO. */
-       if (!(dev->features & NETIF_F_IP_CSUM))
-               return;
-
-       if (!xennet_set_sg(dev, 1))
-               xennet_set_tso(dev, 1);
+       return 0;
 }
 
 static int xennet_connect(struct net_device *dev)
@@ -1582,7 +1574,7 @@ static int xennet_connect(struct net_device *dev)
        if (err)
                return err;
 
-       xennet_set_features(dev);
+       netdev_update_features(dev);
 
        spin_lock_bh(&np->rx_lock);
        spin_lock_irq(&np->tx_lock);
@@ -1710,9 +1702,6 @@ static void xennet_get_strings(struct net_device *dev, 
u32 stringset, u8 * data)
 
 static const struct ethtool_ops xennet_ethtool_ops =
 {
-       .set_tx_csum = ethtool_op_set_tx_csum,
-       .set_sg = xennet_set_sg,
-       .set_tso = xennet_set_tso,
        .get_link = ethtool_op_get_link,
 
        .get_sset_count = xennet_get_sset_count,
-- 
1.7.2.3


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel