feature-gso-tcpv4-prefix uses precedes the packet data passed to
the frontend with a ring entry that contains the necessary
metadata. This style of GSO passing is required for Citrix
Windows PV Drivers.
Signed-off-by: Paul Durrant <paul.durrant@xxxxxxxxxx>
Cc: Ian Campbell <ian.campbell@xxxxxxxxxx>
---
drivers/xen/netback/common.h | 3 +-
drivers/xen/netback/netback.c | 43 ++++++++++++++++++++++++++++++++++---
drivers/xen/netback/xenbus.c | 17 +++++++++++---
include/xen/interface/io/netif.h | 4 +++
4 files changed, 58 insertions(+), 9 deletions(-)
diff --git a/drivers/xen/netback/common.h b/drivers/xen/netback/common.h
index 857778c..1cbc4ff 100644
--- a/drivers/xen/netback/common.h
+++ b/drivers/xen/netback/common.h
@@ -82,7 +82,8 @@ struct xen_netif {
int smart_poll;
/* Internal feature information. */
- u8 can_queue:1; /* can queue packets for receiver? */
+ u8 can_queue:1; /* can queue packets for receiver? */
+ u8 gso_prefix:1; /* use a prefix segment for GSO information */
/* Allow netif_be_start_xmit() to peek ahead in the rx request
* ring. This is a prediction of what rx_req_cons will be once
diff --git a/drivers/xen/netback/netback.c b/drivers/xen/netback/netback.c
index c8f5c1b..93f0686 100644
--- a/drivers/xen/netback/netback.c
+++ b/drivers/xen/netback/netback.c
@@ -313,8 +313,12 @@ int netif_be_start_xmit(struct sk_buff *skb, struct
net_device *dev)
netbk = &xen_netbk[netif->group];
+ /* Drop the packet if the netif is not up or there is no carrier. */
+ if (unlikely(!netif_schedulable(netif)))
+ goto drop;
+
/* Drop the packet if the target domain has no receive buffers. */
- if (unlikely(!netif_schedulable(netif) || netbk_queue_full(netif)))
+ if (unlikely(netbk_queue_full(netif)))
goto drop;
/*
@@ -432,6 +436,7 @@ static void netbk_gop_frag_copy(struct xen_netif *netif,
/* Overflowed this request, go to the next one */
req = RING_GET_REQUEST(&netif->rx,
netif->rx.req_cons++);
meta = npo->meta + npo->meta_prod++;
+ meta->gso_size = 0;
meta->size = 0;
meta->id = req->id;
npo->copy_off = 0;
@@ -492,9 +497,23 @@ static int netbk_gop_skb(struct sk_buff *skb,
old_meta_prod = npo->meta_prod;
+ /* Set up a GSO prefix descriptor, if necessary */
+ if (skb_shinfo(skb)->gso_size && netif->gso_prefix) {
+ req = RING_GET_REQUEST(&netif->rx, netif->rx.req_cons++);
+ meta = npo->meta + npo->meta_prod++;
+ meta->gso_size = skb_shinfo(skb)->gso_size;
+ meta->size = 0;
+ meta->id = req->id;
+ }
+
req = RING_GET_REQUEST(&netif->rx, netif->rx.req_cons++);
meta = npo->meta + npo->meta_prod++;
- meta->gso_size = skb_shinfo(skb)->gso_size;
+
+ if (!netif->gso_prefix)
+ meta->gso_size = skb_shinfo(skb)->gso_size;
+ else
+ meta->gso_size = 0;
+
meta->size = 0;
meta->id = req->id;
npo->copy_off = 0;
@@ -506,7 +525,7 @@ static int netbk_gop_skb(struct sk_buff *skb,
offset_in_page(skb->data), 1);
/* Leave a gap for the GSO descriptor. */
- if (skb_shinfo(skb)->gso_size)
+ if (skb_shinfo(skb)->gso_size && !netif->gso_prefix)
netif->rx.req_cons++;
for (i = 0; i < nr_frags; i++) {
@@ -623,6 +642,21 @@ static void net_rx_action(unsigned long data)
netif = netdev_priv(skb->dev);
+ if (netbk->meta[npo.meta_cons].gso_size && netif->gso_prefix) {
+ resp = RING_GET_RESPONSE(&netif->rx,
+ netif->rx.rsp_prod_pvt++);
+
+ resp->flags = NETRXF_gso_prefix | NETRXF_more_data;
+
+ resp->offset = netbk->meta[npo.meta_cons].gso_size;
+ resp->id = netbk->meta[npo.meta_cons].id;
+ resp->status = sco->meta_slots_used;
+
+ npo.meta_cons++;
+ sco->meta_slots_used--;
+ }
+
+
netif->stats.tx_bytes += skb->len;
netif->stats.tx_packets++;
@@ -633,6 +667,7 @@ static void net_rx_action(unsigned long data)
flags = 0;
else
flags = NETRXF_more_data;
+
if (skb->ip_summed == CHECKSUM_PARTIAL) /* local packet? */
flags |= NETRXF_csum_blank | NETRXF_data_validated;
else if (skb->ip_summed == CHECKSUM_UNNECESSARY)
@@ -645,7 +680,7 @@ static void net_rx_action(unsigned long data)
netbk->meta[npo.meta_cons].size,
flags);
- if (netbk->meta[npo.meta_cons].gso_size) {
+ if (netbk->meta[npo.meta_cons].gso_size && !netif->gso_prefix) {
struct xen_netif_extra_info *gso =
(struct xen_netif_extra_info *)
RING_GET_RESPONSE(&netif->rx,
diff --git a/drivers/xen/netback/xenbus.c b/drivers/xen/netback/xenbus.c
index ba7b1de..74c035b 100644
--- a/drivers/xen/netback/xenbus.c
+++ b/drivers/xen/netback/xenbus.c
@@ -465,16 +465,25 @@ static int connect_rings(struct backend_info *be)
be->netif->dev->mtu = ETH_DATA_LEN;
}
- if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-gso-tcpv4", "%d",
- &val) < 0)
+ 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;
}
+ if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-gso-tcpv4-prefix",
+ "%d", &val) < 0)
+ val = 0;
+ if (val) {
+ be->netif->features |= NETIF_F_TSO;
+ be->netif->dev->features |= NETIF_F_TSO;
+ be->netif->gso_prefix = 1;
+ }
+
if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-no-csum-offload",
- "%d", &val) < 0)
+ "%d", &val) < 0)
val = 0;
if (val) {
be->netif->features &= ~NETIF_F_IP_CSUM;
@@ -482,7 +491,7 @@ static int connect_rings(struct backend_info *be)
}
if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-smart-poll",
- "%d", &val) < 0)
+ "%d", &val) < 0)
val = 0;
if (val)
be->netif->smart_poll = 1;
diff --git a/include/xen/interface/io/netif.h b/include/xen/interface/io/netif.h
index 518481c..8309344 100644
--- a/include/xen/interface/io/netif.h
+++ b/include/xen/interface/io/netif.h
@@ -131,6 +131,10 @@ struct xen_netif_rx_request {
#define _NETRXF_extra_info (3)
#define NETRXF_extra_info (1U<<_NETRXF_extra_info)
+/* GSO Prefix descriptor. */
+#define _NETRXF_gso_prefix (4)
+#define NETRXF_gso_prefix (1U<<_NETRXF_gso_prefix)
+
struct xen_netif_rx_response {
uint16_t id;
uint16_t offset; /* Offset in page of start of received packet */
--
1.5.6.5
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