xen-netback: pass toeplitz hash value to the frontend

My recent patch to include/xen/interface/io/netif.h defines a new extra
info type that can be used to pass toeplitz hash values between backend
and VM frontend.

This patch adds code to xen-netback to pass hash values calculated for
receive-side packets to the VM frontend.

Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Cc: Ian Campbell <ian.campbell@citrix.com>
Cc: Wei Liu <wei.liu2@citrix.com>

diff --git a/drivers/net/xen-netback/common.h b/drivers/net/xen-netback/common.h
index 6687702b276451258f63971cd9f50352cd9051a6..469dcf0cf65ad3b2b590848efc9091478b39ecd5 100644 (file)
--- a/drivers/net/xen-netback/common.h
+++ b/drivers/net/xen-netback/common.h
@@ -243,6 +243,7 @@ struct xenvif {
        u8 ip_csum:1;
        u8 ipv6_csum:1;
        u8 multicast_control:1;
+       u8 hash_extra:1;
 
        /* Is this interface disabled? True when backend discovers
         * frontend is rogue.

diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c
index 157b17d06a9a3d2b3781fdd452c41e5634ee3325..f550b8afc36f228cf0a10140454cb471086079fd 100644 (file)
--- a/drivers/net/xen-netback/netback.c
+++ b/drivers/net/xen-netback/netback.c
@@ -163,6 +163,8 @@ static bool xenvif_rx_ring_slots_available(struct xenvif_queue *queue)
        needed = DIV_ROUND_UP(skb->len, XEN_PAGE_SIZE);
        if (skb_is_gso(skb))
                needed++;
+       if (queue->vif->hash_extra)
+               needed++;
 
        do {
                prod = queue->rx.sring->req_prod;
@@ -280,6 +282,8 @@ struct gop_frag_copy {
        struct xenvif_rx_meta *meta;
        int head;
        int gso_type;
+       int protocol;
+       int hash_type;
 
        struct page *page;
 };
@@ -326,8 +330,19 @@ static void xenvif_setup_copy_gop(unsigned long gfn,
        npo->copy_off += *len;
        info->meta->size += *len;
 
+       if (!info->head)
+               return;
+
        /* Leave a gap for the GSO descriptor. */
-       if (info->head && ((1 << info->gso_type) & queue->vif->gso_mask))
+       if ((1 << info->gso_type) & queue->vif->gso_mask)
+               queue->rx.req_cons++;
+
+       /* Leave a gap for the hash extra segment. */
+       if (queue->vif->hash_extra &&
+           (info->hash_type == PKT_HASH_TYPE_L4 ||
+            info->hash_type == PKT_HASH_TYPE_L3) &&
+           (info->protocol == htons(ETH_P_IP) ||
+            info->protocol == htons(ETH_P_IPV6)))
                queue->rx.req_cons++;
 
        info->head = 0; /* There must be something in this buffer now */
@@ -362,6 +377,8 @@ static void xenvif_gop_frag_copy(struct xenvif_queue *queue, struct sk_buff *skb
                .npo = npo,
                .head = *head,
                .gso_type = XEN_NETIF_GSO_TYPE_NONE,
+               .protocol = skb->protocol,
+               .hash_type = skb_hash_type(skb),
        };
        unsigned long bytes;
 
@@ -550,6 +567,7 @@ void xenvif_kick_thread(struct xenvif_queue *queue)
 
 static void xenvif_rx_action(struct xenvif_queue *queue)
 {
+       struct xenvif *vif = queue->vif;
        s8 status;
        u16 flags;
        struct xen_netif_rx_response *resp;
@@ -567,6 +585,8 @@ static void xenvif_rx_action(struct xenvif_queue *queue)
 
        skb_queue_head_init(&rxq);
 
+       vif->hash_extra = !!vif->toeplitz.flags;
+
        while (xenvif_rx_ring_slots_available(queue)
               && (skb = xenvif_rx_dequeue(queue)) != NULL) {
                queue->last_rx_time = jiffies;
@@ -585,9 +605,10 @@ static void xenvif_rx_action(struct xenvif_queue *queue)
        gnttab_batch_copy(queue->grant_copy_op, npo.copy_prod);
 
        while ((skb = __skb_dequeue(&rxq)) != NULL) {
+               struct xen_netif_extra_info *extra = NULL;
 
                if ((1 << queue->meta[npo.meta_cons].gso_type) &
-                   queue->vif->gso_prefix_mask) {
+                   vif->gso_prefix_mask) {
                        resp = RING_GET_RESPONSE(&queue->rx,
                                                 queue->rx.rsp_prod_pvt++);
 
@@ -605,7 +626,7 @@ static void xenvif_rx_action(struct xenvif_queue *queue)
                queue->stats.tx_bytes += skb->len;
                queue->stats.tx_packets++;
 
-               status = xenvif_check_gop(queue->vif,
+               status = xenvif_check_gop(vif,
                                          XENVIF_RX_CB(skb)->meta_slots_used,
                                          &npo);
 
@@ -627,21 +648,52 @@ static void xenvif_rx_action(struct xenvif_queue *queue)
                                        flags);
 
                if ((1 << queue->meta[npo.meta_cons].gso_type) &
-                   queue->vif->gso_mask) {
-                       struct xen_netif_extra_info *gso =
-                               (struct xen_netif_extra_info *)
+                   vif->gso_mask) {
+                       extra = (struct xen_netif_extra_info *)
                                RING_GET_RESPONSE(&queue->rx,
                                                  queue->rx.rsp_prod_pvt++);
 
                        resp->flags |= XEN_NETRXF_extra_info;
 
-                       gso->u.gso.type = queue->meta[npo.meta_cons].gso_type;
-                       gso->u.gso.size = queue->meta[npo.meta_cons].gso_size;
-                       gso->u.gso.pad = 0;
-                       gso->u.gso.features = 0;
+                       extra->u.gso.type = queue->meta[npo.meta_cons].gso_type;
+                       extra->u.gso.size = queue->meta[npo.meta_cons].gso_size;
+                       extra->u.gso.pad = 0;
+                       extra->u.gso.features = 0;
+
+                       extra->type = XEN_NETIF_EXTRA_TYPE_GSO;
+                       extra->flags = 0;
+               }
+
+               if (vif->hash_extra &&
+                   (skb_hash_type(skb) == PKT_HASH_TYPE_L4 ||
+                    skb_hash_type(skb) == PKT_HASH_TYPE_L3) &&
+                   (skb->protocol == htons(ETH_P_IP) ||
+                    skb->protocol == htons(ETH_P_IPV6))) {
+                       if (resp->flags & XEN_NETRXF_extra_info)
+                               extra->flags |= XEN_NETIF_EXTRA_FLAG_MORE;
+                       else
+                               resp->flags |= XEN_NETRXF_extra_info;
+
+                       extra = (struct xen_netif_extra_info *)
+                               RING_GET_RESPONSE(&queue->rx,
+                                                 queue->rx.rsp_prod_pvt++);
 
-                       gso->type = XEN_NETIF_EXTRA_TYPE_GSO;
-                       gso->flags = 0;
+                       if (skb_hash_type(skb) == PKT_HASH_TYPE_L4)
+                               extra->u.toeplitz.type =
+                                       skb->protocol == htons(ETH_P_IP) ?
+                                       _XEN_NETIF_CTRL_TOEPLITZ_HASH_IPV4_TCP :
+                                       _XEN_NETIF_CTRL_TOEPLITZ_HASH_IPV6_TCP;
+                       else if (skb_hash_type(skb) == PKT_HASH_TYPE_L3)
+                               extra->u.toeplitz.type =
+                                       skb->protocol == htons(ETH_P_IP) ?
+                                       _XEN_NETIF_CTRL_TOEPLITZ_HASH_IPV4 :
+                                       _XEN_NETIF_CTRL_TOEPLITZ_HASH_IPV6;
+
+                       *(uint32_t *)extra->u.toeplitz.value =
+                               skb_get_hash_raw(skb);
+
+                       extra->type = XEN_NETIF_EXTRA_TYPE_TOEPLITZ;
+                       extra->flags = 0;
                }
 
                xenvif_add_frag_responses(queue, status,