xen-netback: enable IPv6 TCP GSO to the guest

This patch adds code to handle SKB_GSO_TCPV6 skbs and construct appropriate
extra or prefix segments to pass the large packet to the frontend. New
xenstore flags, feature-gso-tcpv6 and feature-gso-tcpv6-prefix, are sampled
to determine if the frontend is capable of handling such packets.

Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Cc: Wei Liu <wei.liu2@citrix.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/xen-netback/common.h b/drivers/net/xen-netback/common.h
index b4a9a3c..55b8dec 100644 (file)
--- a/drivers/net/xen-netback/common.h
+++ b/drivers/net/xen-netback/common.h
@@ -87,9 +87,13 @@ struct pending_tx_info {
 struct xenvif_rx_meta {
        int id;
        int size;
+       int gso_type;
        int gso_size;
 };
 
+#define GSO_BIT(type) \
+       (1 << XEN_NETIF_GSO_TYPE_ ## type)
+
 /* Discriminate from any valid pending_idx value. */
 #define INVALID_PENDING_IDX 0xFFFF
 
@@ -150,9 +154,10 @@ struct xenvif {
        u8               fe_dev_addr[6];
 
        /* Frontend feature information. */
+       int gso_mask;
+       int gso_prefix_mask;
+
        u8 can_sg:1;
-       u8 gso:1;
-       u8 gso_prefix:1;
        u8 ip_csum:1;
        u8 ipv6_csum:1;
 

diff --git a/drivers/net/xen-netback/interface.c b/drivers/net/xen-netback/interface.c
index cb0d8ea..e4aa267 100644 (file)
--- a/drivers/net/xen-netback/interface.c
+++ b/drivers/net/xen-netback/interface.c
@@ -214,8 +214,10 @@ static netdev_features_t xenvif_fix_features(struct net_device *dev,
 
        if (!vif->can_sg)
                features &= ~NETIF_F_SG;
-       if (!vif->gso && !vif->gso_prefix)
+       if (~(vif->gso_mask | vif->gso_prefix_mask) & GSO_BIT(TCPV4))
                features &= ~NETIF_F_TSO;
+       if (~(vif->gso_mask | vif->gso_prefix_mask) & GSO_BIT(TCPV6))
+               features &= ~NETIF_F_TSO6;
        if (!vif->ip_csum)
                features &= ~NETIF_F_IP_CSUM;
        if (!vif->ipv6_csum)
@@ -320,7 +322,7 @@ struct xenvif *xenvif_alloc(struct device *parent, domid_t domid,
        dev->netdev_ops = &xenvif_netdev_ops;
        dev->hw_features = NETIF_F_SG |
                NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM |
-               NETIF_F_TSO;
+               NETIF_F_TSO | NETIF_F_TSO6;
        dev->features = dev->hw_features | NETIF_F_RXCSUM;
        SET_ETHTOOL_OPS(dev, &xenvif_ethtool_ops);
 

diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c
index 0e327d4..828fdab 100644 (file)
--- a/drivers/net/xen-netback/netback.c
+++ b/drivers/net/xen-netback/netback.c
@@ -142,7 +142,7 @@ static int max_required_rx_slots(struct xenvif *vif)
        int max = DIV_ROUND_UP(vif->dev->mtu, PAGE_SIZE);
 
        /* XXX FIXME: RX path dependent on MAX_SKB_FRAGS */
-       if (vif->can_sg || vif->gso || vif->gso_prefix)
+       if (vif->can_sg || vif->gso_mask || vif->gso_prefix_mask)
                max += MAX_SKB_FRAGS + 1; /* extra_info + frags */
 
        return max;
@@ -314,6 +314,7 @@ static struct xenvif_rx_meta *get_next_rx_buffer(struct xenvif *vif,
        req = RING_GET_REQUEST(&vif->rx, vif->rx.req_cons++);
 
        meta = npo->meta + npo->meta_prod++;
+       meta->gso_type = XEN_NETIF_GSO_TYPE_NONE;
        meta->gso_size = 0;
        meta->size = 0;
        meta->id = req->id;
@@ -336,6 +337,7 @@ static void xenvif_gop_frag_copy(struct xenvif *vif, struct sk_buff *skb,
        struct gnttab_copy *copy_gop;
        struct xenvif_rx_meta *meta;
        unsigned long bytes;
+       int gso_type;
 
        /* Data must not cross a page boundary. */
        BUG_ON(size + offset > PAGE_SIZE<<compound_order(page));
@@ -394,7 +396,14 @@ static void xenvif_gop_frag_copy(struct xenvif *vif, struct sk_buff *skb,
                }
 
                /* Leave a gap for the GSO descriptor. */
-               if (*head && skb_shinfo(skb)->gso_size && !vif->gso_prefix)
+               if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
+                       gso_type = XEN_NETIF_GSO_TYPE_TCPV4;
+               else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
+                       gso_type = XEN_NETIF_GSO_TYPE_TCPV6;
+               else
+                       gso_type = XEN_NETIF_GSO_TYPE_NONE;
+
+               if (*head && ((1 << gso_type) & vif->gso_mask))
                        vif->rx.req_cons++;
 
                *head = 0; /* There must be something in this buffer now. */
@@ -425,14 +434,28 @@ static int xenvif_gop_skb(struct sk_buff *skb,
        unsigned char *data;
        int head = 1;
        int old_meta_prod;
+       int gso_type;
+       int gso_size;
 
        old_meta_prod = npo->meta_prod;
 
+       if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4) {
+               gso_type = XEN_NETIF_GSO_TYPE_TCPV4;
+               gso_size = skb_shinfo(skb)->gso_size;
+       } else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6) {
+               gso_type = XEN_NETIF_GSO_TYPE_TCPV6;
+               gso_size = skb_shinfo(skb)->gso_size;
+       } else {
+               gso_type = XEN_NETIF_GSO_TYPE_NONE;
+               gso_size = 0;
+       }
+
        /* Set up a GSO prefix descriptor, if necessary */
-       if (skb_shinfo(skb)->gso_size && vif->gso_prefix) {
+       if ((1 << skb_shinfo(skb)->gso_type) & vif->gso_prefix_mask) {
                req = RING_GET_REQUEST(&vif->rx, vif->rx.req_cons++);
                meta = npo->meta + npo->meta_prod++;
-               meta->gso_size = skb_shinfo(skb)->gso_size;
+               meta->gso_type = gso_type;
+               meta->gso_size = gso_size;
                meta->size = 0;
                meta->id = req->id;
        }
@@ -440,10 +463,13 @@ static int xenvif_gop_skb(struct sk_buff *skb,
        req = RING_GET_REQUEST(&vif->rx, vif->rx.req_cons++);
        meta = npo->meta + npo->meta_prod++;
 
-       if (!vif->gso_prefix)
-               meta->gso_size = skb_shinfo(skb)->gso_size;
-       else
+       if ((1 << gso_type) & vif->gso_mask) {
+               meta->gso_type = gso_type;
+               meta->gso_size = gso_size;
+       } else {
+               meta->gso_type = XEN_NETIF_GSO_TYPE_NONE;
                meta->gso_size = 0;
+       }
 
        meta->size = 0;
        meta->id = req->id;
@@ -589,7 +615,8 @@ void xenvif_rx_action(struct xenvif *vif)
 
                vif = netdev_priv(skb->dev);
 
-               if (vif->meta[npo.meta_cons].gso_size && vif->gso_prefix) {
+               if ((1 << vif->meta[npo.meta_cons].gso_type) &
+                   vif->gso_prefix_mask) {
                        resp = RING_GET_RESPONSE(&vif->rx,
                                                 vif->rx.rsp_prod_pvt++);
 
@@ -626,7 +653,8 @@ void xenvif_rx_action(struct xenvif *vif)
                                        vif->meta[npo.meta_cons].size,
                                        flags);
 
-               if (vif->meta[npo.meta_cons].gso_size && !vif->gso_prefix) {
+               if ((1 << vif->meta[npo.meta_cons].gso_type) &
+                   vif->gso_mask) {
                        struct xen_netif_extra_info *gso =
                                (struct xen_netif_extra_info *)
                                RING_GET_RESPONSE(&vif->rx,
@@ -634,8 +662,8 @@ void xenvif_rx_action(struct xenvif *vif)
 
                        resp->flags |= XEN_NETRXF_extra_info;
 
+                       gso->u.gso.type = vif->meta[npo.meta_cons].gso_type;
                        gso->u.gso.size = vif->meta[npo.meta_cons].gso_size;
-                       gso->u.gso.type = XEN_NETIF_GSO_TYPE_TCPV4;
                        gso->u.gso.pad = 0;
                        gso->u.gso.features = 0;
 

diff --git a/drivers/net/xen-netback/xenbus.c b/drivers/net/xen-netback/xenbus.c
index 02cb00b..f035899 100644 (file)
--- a/drivers/net/xen-netback/xenbus.c
+++ b/drivers/net/xen-netback/xenbus.c
@@ -577,15 +577,40 @@ static int connect_rings(struct backend_info *be)
                val = 0;
        vif->can_sg = !!val;
 
+       vif->gso_mask = 0;
+       vif->gso_prefix_mask = 0;
+
        if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-gso-tcpv4",
                         "%d", &val) < 0)
                val = 0;
-       vif->gso = !!val;
+       if (val)
+               vif->gso_mask |= GSO_BIT(TCPV4);
 
        if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-gso-tcpv4-prefix",
                         "%d", &val) < 0)
                val = 0;
-       vif->gso_prefix = !!val;
+       if (val)
+               vif->gso_prefix_mask |= GSO_BIT(TCPV4);
+
+       if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-gso-tcpv6",
+                        "%d", &val) < 0)
+               val = 0;
+       if (val)
+               vif->gso_mask |= GSO_BIT(TCPV6);
+
+       if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-gso-tcpv6-prefix",
+                        "%d", &val) < 0)
+               val = 0;
+       if (val)
+               vif->gso_prefix_mask |= GSO_BIT(TCPV6);
+
+       if (vif->gso_mask & vif->gso_prefix_mask) {
+               xenbus_dev_fatal(dev, err,
+                                "%s: gso and gso prefix flags are not "
+                                "mutually exclusive",
+                                dev->otherend);
+               return -EOPNOTSUPP;
+       }
 
        if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-no-csum-offload",
                         "%d", &val) < 0)

diff --git a/include/xen/interface/io/netif.h b/include/xen/interface/io/netif.h
index 5e766eb..c50061d 100644 (file)
--- a/include/xen/interface/io/netif.h
+++ b/include/xen/interface/io/netif.h
@@ -110,6 +110,7 @@ struct xen_netif_tx_request {
 #define  XEN_NETIF_EXTRA_FLAG_MORE     (1U<<_XEN_NETIF_EXTRA_FLAG_MORE)
 
 /* GSO types */
+#define XEN_NETIF_GSO_TYPE_NONE                (0)
 #define XEN_NETIF_GSO_TYPE_TCPV4       (1)
 #define XEN_NETIF_GSO_TYPE_TCPV6       (2)