From 2167ca029c2449018314fdf8637c1eb3f123036e Mon Sep 17 00:00:00 2001 From: Ross Lagerwall Date: Tue, 4 Oct 2016 10:29:18 +0100 Subject: [PATCH] xen/netback: add fraglist support for to-guest rx This allows full 64K skbuffs (with 1500 mtu ethernet, composed of 45 fragments) to be handled by netback for to-guest rx. Signed-off-by: Ross Lagerwall [re-based] Signed-off-by: Paul Durrant Reviewed-by: David Vrabel Signed-off-by: David S. Miller --- drivers/net/xen-netback/interface.c | 2 +- drivers/net/xen-netback/rx.c | 38 ++++++++++++++++++++++------- 2 files changed, 30 insertions(+), 10 deletions(-) diff --git a/drivers/net/xen-netback/interface.c b/drivers/net/xen-netback/interface.c index 211d542a830b..4af532a67d95 100644 --- a/drivers/net/xen-netback/interface.c +++ b/drivers/net/xen-netback/interface.c @@ -467,7 +467,7 @@ 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_TSO6; + NETIF_F_TSO | NETIF_F_TSO6 | NETIF_F_FRAGLIST; dev->features = dev->hw_features | NETIF_F_RXCSUM; dev->ethtool_ops = &xenvif_ethtool_ops; diff --git a/drivers/net/xen-netback/rx.c b/drivers/net/xen-netback/rx.c index 8c8c5b5883eb..8e9ade6ccf18 100644 --- a/drivers/net/xen-netback/rx.c +++ b/drivers/net/xen-netback/rx.c @@ -215,7 +215,8 @@ static unsigned int xenvif_gso_type(struct sk_buff *skb) struct xenvif_pkt_state { struct sk_buff *skb; size_t remaining_len; - int frag; /* frag == -1 => skb->head */ + struct sk_buff *frag_iter; + int frag; /* frag == -1 => frag_iter->head */ unsigned int frag_offset; struct xen_netif_extra_info extras[XEN_NETIF_EXTRA_TYPE_MAX - 1]; unsigned int extra_count; @@ -237,6 +238,7 @@ static void xenvif_rx_next_skb(struct xenvif_queue *queue, memset(pkt, 0, sizeof(struct xenvif_pkt_state)); pkt->skb = skb; + pkt->frag_iter = skb; pkt->remaining_len = skb->len; pkt->frag = -1; @@ -293,20 +295,40 @@ static void xenvif_rx_complete(struct xenvif_queue *queue, __skb_queue_tail(queue->rx_copy.completed, pkt->skb); } +static void xenvif_rx_next_frag(struct xenvif_pkt_state *pkt) +{ + struct sk_buff *frag_iter = pkt->frag_iter; + unsigned int nr_frags = skb_shinfo(frag_iter)->nr_frags; + + pkt->frag++; + pkt->frag_offset = 0; + + if (pkt->frag >= nr_frags) { + if (frag_iter == pkt->skb) + pkt->frag_iter = skb_shinfo(frag_iter)->frag_list; + else + pkt->frag_iter = frag_iter->next; + + pkt->frag = -1; + } +} + static void xenvif_rx_next_chunk(struct xenvif_queue *queue, struct xenvif_pkt_state *pkt, unsigned int offset, void **data, size_t *len) { - struct sk_buff *skb = pkt->skb; + struct sk_buff *frag_iter = pkt->frag_iter; void *frag_data; size_t frag_len, chunk_len; + BUG_ON(!frag_iter); + if (pkt->frag == -1) { - frag_data = skb->data; - frag_len = skb_headlen(skb); + frag_data = frag_iter->data; + frag_len = skb_headlen(frag_iter); } else { - skb_frag_t *frag = &skb_shinfo(skb)->frags[pkt->frag]; + skb_frag_t *frag = &skb_shinfo(frag_iter)->frags[pkt->frag]; frag_data = skb_frag_address(frag); frag_len = skb_frag_size(frag); @@ -322,10 +344,8 @@ static void xenvif_rx_next_chunk(struct xenvif_queue *queue, pkt->frag_offset += chunk_len; /* Advance to next frag? */ - if (frag_len == chunk_len) { - pkt->frag++; - pkt->frag_offset = 0; - } + if (frag_len == chunk_len) + xenvif_rx_next_frag(pkt); *data = frag_data; *len = chunk_len; -- 2.20.1