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

[Ian Campbell <Ian.Campbell@xxxxxxxxxxxxx>]

On Thu, 2011-03-31 at 12:01 +0100, MichaÅ MirosÅaw wrote:
> Not tested in any way. The original code for offload setting seems broken
> as it resets the features on every netback reconnect.

Thanks, I've got a pending TODO item to test this and propagate similar
changes to netback. I hope to get to it soon...

Is this urgent (for 2.6.39) IYHO? I think it's been broken this way for
a long time now...

Ian.

> 
> This will set GSO_ROBUST at device creation time (earlier than connect time).
> 
> RX checksum offload is forced on - so advertise as it is.
> 
> Signed-off-by: MichaÅ MirosÅaw <mirq-linux@xxxxxxxxxxxx>
> ---
> [I don't know Xen code enough to say this is correct. There is Xen netback
> driver coming in, that has similar changes to be made. Please match
> them up if you can.]
> 
>  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 5c8d9c3..2a71c9f 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,



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