Re: [Xen-devel] Trying to adapt Olaf's vif MTU patch for EL5.6's 2.6.18-238.9 kernel - patch in-line.

[Teck Choon Giam <giamteckchoon@xxxxxxxxx>]

On Sun, Apr 17, 2011 at 9:44 AM, Digimer <linux@xxxxxxxxxxx> wrote:
> Hi all,
>
>  As per the request on ##xen, I'm reposting this with patches and
> diff's inline. Please ignore my earlier post.
>
>  With a *lot* of help from Pasi yesterday, I was trying to get Olaf's
> vif MTU patch
> (http://lists.xensource.com/archives/html/xen-devel/2011-02/msg00352.html)
> applied against the most recent EL5.6 (RHEL 5.6/CentOS 5.6) kernel
> version 2.6.18-238.9.
>
>  The patch as-is didn't apply cleanly, as there seemed to be a line
> shift issue with common.h and xenbus.c. I manually added the lines and
> created a new patch, but I screwed something up and it fails to compile.
> I should note that I am /not/ a C programmer. :)
>
>  Here is adapted patch:
>
> ====
> --- linux-2.6.18.x86_64/drivers/xen/netback/common.h.orig       2011-04-15
> 17:46:12.730677042 -0400
> +++ linux-2.6.18.x86_64/drivers/xen/netback/common.h    2011-04-15
> 17:57:57.490721792 -0400
> @@ -76,8 +76,13 @@
>        struct vm_struct *tx_comms_area;
>        struct vm_struct *rx_comms_area;
>
> -       /* Set of features that can be turned on in dev->features. */
> -       int features;
> +       /* Flags that must not be set in dev->features */
> +       int features_disabled;
> +
> +       /* Frontend feature information. */
> +       u8 can_sg:1;
> +       u8 gso:1;
> +       u8 csum:1;
>
>        /* Internal feature information. */
>        int can_queue:1;        /* can queue packets for receiver? */
> @@ -110,6 +115,7 @@
>
>  void netif_disconnect(netif_t *netif);
>
> +void netif_set_features(netif_t *netif);
>  netif_t *netif_alloc(domid_t domid, unsigned int handle);
>  int netif_map(netif_t *netif, unsigned long tx_ring_ref,
>              unsigned long rx_ring_ref, unsigned int evtchn);
> @@ -142,7 +148,7 @@
>  static inline int netbk_can_sg(struct net_device *dev)
>  {
>        netif_t *netif = netdev_priv(dev);
> -       return netif->features & NETIF_F_SG;
> +       return netif->can_sg;
>  }
>
>  #endif /* __NETIF__BACKEND__COMMON_H__ */
> --- linux-2.6.18.x86_64/drivers/xen/netback/interface.c.orig    2011-04-15
> 17:46:57.205456542 -0400
> +++ linux-2.6.18.x86_64/drivers/xen/netback/interface.c 2011-04-15
> 17:50:46.027757042 -0400
> @@ -90,34 +90,75 @@
>        return 0;
>  }
>
> -static int netbk_set_sg(struct net_device *dev, u32 data)
> +void netif_set_features(netif_t *netif)
>  {
> +       struct net_device *dev = netif->dev;
> +       int features = dev->features;
> +
> +       if (netif->can_sg)
> +               features |= NETIF_F_SG;
> +       if (netif->gso)
> +               features |= NETIF_F_TSO;
> +       if (netif->csum)
> +               features |= NETIF_F_IP_CSUM;
> +
> +       features &= ~(netif->features_disabled);
> +
> +       if (!(features & NETIF_F_SG) && dev->mtu > ETH_DATA_LEN)
> +               dev->mtu = ETH_DATA_LEN;
> +
> +       dev->features = features;
> +}
> +
> +static int netbk_set_tx_csum(struct net_device *dev, u32 data)
> +{
> +       netif_t *netif = netdev_priv(dev);
>        if (data) {
> -               netif_t *netif = netdev_priv(dev);
> +               if (!netif->csum)
> +                       return -ENOSYS;
> +               netif->features_disabled &= ~NETIF_F_IP_CSUM;
> +       } else {
> +               netif->features_disabled |= NETIF_F_IP_CSUM;
> +       }
>
> -               if (!(netif->features & NETIF_F_SG))
> +       netif_set_features(netif);
> +       return 0;
> +}
> +
> +static int netbk_set_sg(struct net_device *dev, u32 data)
> +{
> +       netif_t *netif = netdev_priv(dev);
> +       if (data) {
> +               if (!netif->can_sg)
>                        return -ENOSYS;
> +               netif->features_disabled &= ~NETIF_F_SG;
> +       } else {
> +               netif->features_disabled |= NETIF_F_SG;
>        }
>
> -       return ethtool_op_set_sg(dev, data);
> +       netif_set_features(netif);
> +       return 0;
>  }
>
>  static int netbk_set_tso(struct net_device *dev, u32 data)
>  {
> +       netif_t *netif = netdev_priv(dev);
>        if (data) {
> -               netif_t *netif = netdev_priv(dev);
> -
> -               if (!(netif->features & NETIF_F_TSO))
> +               if (!netif->gso)
>                        return -ENOSYS;
> +               netif->features_disabled &= ~NETIF_F_TSO;
> +       } else {
> +               netif->features_disabled |= NETIF_F_TSO;
>        }
>
> -       return ethtool_op_set_tso(dev, data);
> +       netif_set_features(netif);
> +       return 0;
>  }
>
>  static struct ethtool_ops network_ethtool_ops =
>  {
>        .get_tx_csum = ethtool_op_get_tx_csum,
> -       .set_tx_csum = ethtool_op_set_tx_csum,
> +       .set_tx_csum = netbk_set_tx_csum,
>        .get_sg = ethtool_op_get_sg,
>        .set_sg = netbk_set_sg,
>        .get_tso = ethtool_op_get_tso,
> @@ -145,6 +186,8 @@
>        memset(netif, 0, sizeof(*netif));
>        netif->domid  = domid;
>        netif->handle = handle;
> +       netif->can_sg = 1;
> +       netif->csum = 1;
>        atomic_set(&netif->refcnt, 1);
>        init_waitqueue_head(&netif->waiting_to_free);
>        netif->dev = dev;
> @@ -162,7 +205,8 @@
>        dev->open            = net_open;
>        dev->stop            = net_close;
>        dev->change_mtu      = netbk_change_mtu;
> -       dev->features        = NETIF_F_IP_CSUM;
> +
> +       netif_set_features(netif);
>
>        SET_ETHTOOL_OPS(dev, &network_ethtool_ops);
>
> --- linux-2.6.18.x86_64/drivers/xen/netback/netback.c.orig      2011-04-15
> 17:46:58.141515042 -0400
> +++ linux-2.6.18.x86_64/drivers/xen/netback/netback.c   2011-04-15
> 17:50:46.027757042 -0400
> @@ -215,7 +215,7 @@
>
>  static inline int netbk_max_required_rx_slots(netif_t *netif)
>  {
> -       if (netif->features & (NETIF_F_SG|NETIF_F_TSO))
> +       if (netif->can_sg || netif->gso)
>                return MAX_SKB_FRAGS + 2; /* header + extra_info + frags */
>        return 1; /* all in one */
>  }
> --- linux-2.6.18.x86_64/drivers/xen/netback/xenbus.c.orig       2011-04-15
> 17:46:59.217582292 -0400
> +++ linux-2.6.18.x86_64/drivers/xen/netback/xenbus.c    2011-04-15
> 18:13:20.700418792 -0400
> @@ -345,6 +345,7 @@
>
>  static int connect_rings(struct backend_info *be)
>  {
> +       netif_t *netif = be->netif;
>        struct xenbus_device *dev = be->dev;
>        unsigned long tx_ring_ref, rx_ring_ref;
>        unsigned int evtchn, rx_copy;
> @@ -375,46 +376,40 @@
>                                 dev->otherend);
>                return err;
>        }
> -       be->netif->copying_receiver = !!rx_copy;
> +       netif->copying_receiver = !!rx_copy;
>
> -       if (be->netif->dev->tx_queue_len != 0) {
> +       if (netif->dev->tx_queue_len != 0) {
>                if (xenbus_scanf(XBT_NIL, dev->otherend,
>                                 "feature-rx-notify", "%d", &val) < 0)
>                        val = 0;
>                if (val)
> -                       be->netif->can_queue = 1;
> +                       netif->can_queue = 1

You need to end semi-colon for the above which I think your compile
error output is showing I guess.

>                else
>                        /* Must be non-zero for pfifo_fast to work. */
> -                       be->netif->dev->tx_queue_len = 1;
> +                       netif->dev->tx_queue_len = 1;
>        }
>
>        if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-sg", "%d", &val) < 0)
>                val = 0;
> -       if (val) {
> -               be->netif->features |= NETIF_F_SG;
> -               be->netif->dev->features |= NETIF_F_SG;
> -       }
> +       netif->can_sg = !!val;
>
>        if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-gso-tcpv4", "%d",
>                         &val) < 0)
>                val = 0;
> -       if (val) {
> -               be->netif->features |= NETIF_F_TSO;
> -               be->netif->dev->features |= NETIF_F_TSO;
> -       }
> +       netif->gso = !!val;
>
>        if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-no-csum-offload",
>                         "%d", &val) < 0)
>                val = 0;
> -       if (val) {
> -               be->netif->features &= ~NETIF_F_IP_CSUM;
> -               be->netif->dev->features &= ~NETIF_F_IP_CSUM;
> -       }
> +       netif->csum = !val;
> +
> +       /* Set dev->features */
> +       netif_set_features(netif);
>
>        netdev_features_change(be->netif->dev);
>
>        /* Map the shared frame, irq etc. */
> -       err = netif_map(be->netif, tx_ring_ref, rx_ring_ref, evtchn);
> +       err = netif_map(netif, tx_ring_ref, rx_ring_ref, evtchn);
>        if (err) {
>                xenbus_dev_fatal(dev, err,
>                                 "mapping shared-frames %lu/%lu port %u",
> ====
>
>  And here is the compile output with errors:
>
> ====
> drivers/xen/blkfront/blkfront.c: In function 'do_blkif_request':
> drivers/xen/blkfront/blkfront.c:629: warning: format '%lx' expects type
> 'long unsigned int', but argument 4 has type 'sector_t'
> drivers/xen/blktap/blktapmain.c:145: warning: 'set_blkif_reqs' defined
> but not used
> drivers/xen/netback/xenbus.c: In function 'connect_rings':
> drivers/xen/netback/xenbus.c:387: error: expected ';' before 'else'

Is the line 387 the one without the ; above?  I guess so :p

Thanks.

Kindest regards,
Giam Teck Choon

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