From f07f989338587bc2b202f6e3c8e8468c450bd6a2 Mon Sep 17 00:00:00 2001 From: Paul Durrant Date: Fri, 13 May 2016 09:37:28 +0100 Subject: [PATCH] xen-netback: pass 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 hash values between backend and guest frontend. This patch adds code to xen-netback to pass hash values calculated for guest receive-side packets (i.e. netback transmit side) to the frontend. Signed-off-by: Paul Durrant Acked-by: Wei Liu Signed-off-by: David S. Miller --- drivers/net/xen-netback/interface.c | 13 ++++- drivers/net/xen-netback/netback.c | 78 ++++++++++++++++++++++++----- 2 files changed, 77 insertions(+), 14 deletions(-) diff --git a/drivers/net/xen-netback/interface.c b/drivers/net/xen-netback/interface.c index 5a39cdbc217c..1c7f49b5acc1 100644 --- a/drivers/net/xen-netback/interface.c +++ b/drivers/net/xen-netback/interface.c @@ -158,8 +158,17 @@ static u16 xenvif_select_queue(struct net_device *dev, struct sk_buff *skb, struct xenvif *vif = netdev_priv(dev); unsigned int size = vif->hash.size; - if (vif->hash.alg == XEN_NETIF_CTRL_HASH_ALGORITHM_NONE) - return fallback(dev, skb) % dev->real_num_tx_queues; + if (vif->hash.alg == XEN_NETIF_CTRL_HASH_ALGORITHM_NONE) { + u16 index = fallback(dev, skb) % dev->real_num_tx_queues; + + /* Make sure there is no hash information in the socket + * buffer otherwise it would be incorrectly forwarded + * to the frontend. + */ + skb_clear_hash(skb); + + return index; + } xenvif_set_skb_hash(vif, skb); diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c index 1916ab332d60..9d6bd862f3c1 100644 --- a/drivers/net/xen-netback/netback.c +++ b/drivers/net/xen-netback/netback.c @@ -168,6 +168,8 @@ 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 (skb->sw_hash) + needed++; do { prod = queue->rx.sring->req_prod; @@ -285,6 +287,8 @@ struct gop_frag_copy { struct xenvif_rx_meta *meta; int head; int gso_type; + int protocol; + int hash_present; struct page *page; }; @@ -331,8 +335,15 @@ 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 (info->hash_present) queue->rx.req_cons++; info->head = 0; /* There must be something in this buffer now */ @@ -367,6 +378,11 @@ 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, + /* xenvif_set_skb_hash() will have either set a s/w + * hash or cleared the hash depending on + * whether the the frontend wants a hash for this skb. + */ + .hash_present = skb->sw_hash, }; unsigned long bytes; @@ -555,6 +571,7 @@ 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; @@ -590,9 +607,10 @@ 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++); @@ -610,7 +628,7 @@ 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); @@ -632,21 +650,57 @@ 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 (skb->sw_hash) { + /* Since the skb got here via xenvif_select_queue() + * we know that the hash has been re-calculated + * according to a configuration set by the frontend + * and therefore we know that it is legitimate to + * pass it to the frontend. + */ + 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; + extra->u.hash.algorithm = + XEN_NETIF_CTRL_HASH_ALGORITHM_TOEPLITZ; + + if (skb->l4_hash) + extra->u.hash.type = + skb->protocol == htons(ETH_P_IP) ? + _XEN_NETIF_CTRL_HASH_TYPE_IPV4_TCP : + _XEN_NETIF_CTRL_HASH_TYPE_IPV6_TCP; + else + extra->u.hash.type = + skb->protocol == htons(ETH_P_IP) ? + _XEN_NETIF_CTRL_HASH_TYPE_IPV4 : + _XEN_NETIF_CTRL_HASH_TYPE_IPV6; + + *(uint32_t *)extra->u.hash.value = + skb_get_hash_raw(skb); + + extra->type = XEN_NETIF_EXTRA_TYPE_HASH; + extra->flags = 0; } xenvif_add_frag_responses(queue, status, -- 2.20.1