the patch basically adds the offset adjustment and netfront
state reading to make XDP work on netfront side.
Signed-off-by: Denis Kirjanov <k...@linux-powerpc.org>
---
drivers/net/xen-netback/common.h | 4 ++++
drivers/net/xen-netback/interface.c | 2 ++
drivers/net/xen-netback/netback.c | 7 +++++++
drivers/net/xen-netback/rx.c | 15 ++++++++++++++-
drivers/net/xen-netback/xenbus.c | 32 ++++++++++++++++++++++++++++++++
5 files changed, 59 insertions(+), 1 deletion(-)
diff --git a/drivers/net/xen-netback/common.h b/drivers/net/xen-netback/common.h
index 05847eb..f14dc10 100644
--- a/drivers/net/xen-netback/common.h
+++ b/drivers/net/xen-netback/common.h
@@ -281,6 +281,9 @@ struct xenvif {
u8 ipv6_csum:1;
u8 multicast_control:1;
+ /* headroom requested by xen-netfront */
+ u16 netfront_xdp_headroom;
+
/* Is this interface disabled? True when backend discovers
* frontend is rogue.
*/
@@ -395,6 +398,7 @@ static inline pending_ring_idx_t nr_pending_reqs(struct
xenvif_queue *queue)
irqreturn_t xenvif_interrupt(int irq, void *dev_id);
extern bool separate_tx_rx_irq;
+extern bool provides_xdp_headroom;
extern unsigned int rx_drain_timeout_msecs;
extern unsigned int rx_stall_timeout_msecs;
diff --git a/drivers/net/xen-netback/interface.c
b/drivers/net/xen-netback/interface.c
index 0c8a02a..fc16edd 100644
--- a/drivers/net/xen-netback/interface.c
+++ b/drivers/net/xen-netback/interface.c
@@ -483,6 +483,8 @@ struct xenvif *xenvif_alloc(struct device *parent, domid_t
domid,
vif->queues = NULL;
vif->num_queues = 0;
+ vif->netfront_xdp_headroom = 0;
+
spin_lock_init(&vif->lock);
INIT_LIST_HEAD(&vif->fe_mcast_addr);
diff --git a/drivers/net/xen-netback/netback.c
b/drivers/net/xen-netback/netback.c
index 315dfc6..6dfca72 100644
--- a/drivers/net/xen-netback/netback.c
+++ b/drivers/net/xen-netback/netback.c
@@ -96,6 +96,13 @@
module_param_named(hash_cache_size, xenvif_hash_cache_size, uint, 0644);
MODULE_PARM_DESC(hash_cache_size, "Number of flows in the hash cache");
+/* The module parameter tells that we have to put data
+ * for xen-netfront with the XDP_PACKET_HEADROOM offset
+ * needed for XDP processing
+ */
+bool provides_xdp_headroom = true;
+module_param(provides_xdp_headroom, bool, 0644);
+
static void xenvif_idx_release(struct xenvif_queue *queue, u16 pending_idx,
u8 status);
diff --git a/drivers/net/xen-netback/rx.c b/drivers/net/xen-netback/rx.c
index ef58870..c5e9e14 100644
--- a/drivers/net/xen-netback/rx.c
+++ b/drivers/net/xen-netback/rx.c
@@ -258,6 +258,19 @@ static void xenvif_rx_next_skb(struct xenvif_queue *queue,
pkt->extra_count++;
}
+ if (queue->vif->netfront_xdp_headroom) {
+ struct xen_netif_extra_info *extra;
+
+ extra = &pkt->extras[XEN_NETIF_EXTRA_TYPE_XDP - 1];
+
+ memset(extra, 0, sizeof(struct xen_netif_extra_info));
+ extra->u.xdp.headroom = queue->vif->netfront_xdp_headroom;
+ extra->type = XEN_NETIF_EXTRA_TYPE_XDP;
+ extra->flags = 0;
+
+ pkt->extra_count++;
+ }
+
if (skb->sw_hash) {
struct xen_netif_extra_info *extra;
@@ -356,7 +369,7 @@ static void xenvif_rx_data_slot(struct xenvif_queue *queue,
struct xen_netif_rx_request *req,
struct xen_netif_rx_response *rsp)
{
- unsigned int offset = 0;
+ unsigned int offset = queue->vif->netfront_xdp_headroom;
unsigned int flags;
do {
diff --git a/drivers/net/xen-netback/xenbus.c b/drivers/net/xen-netback/xenbus.c
index 286054b..c67abc5 100644
--- a/drivers/net/xen-netback/xenbus.c
+++ b/drivers/net/xen-netback/xenbus.c
@@ -393,6 +393,22 @@ static void set_backend_state(struct backend_info *be,
}
}
+static void read_xenbus_frontend_xdp(struct backend_info *be,
+ struct xenbus_device *dev)
+{
+ struct xenvif *vif = be->vif;
+ u16 headroom;
+ int err;
+
+ err = xenbus_scanf(XBT_NIL, dev->otherend,
+ "netfront-xdp-headroom", "%hu", &headroom);
+ if (err < 0) {
+ vif->netfront_xdp_headroom = 0;
+ return;
+ }
+ vif->netfront_xdp_headroom = headroom;
+}
+
/**
* Callback received when the frontend's state changes.
*/
@@ -417,6 +433,11 @@ static void frontend_changed(struct xenbus_device *dev,
set_backend_state(be, XenbusStateConnected);
break;
+ case XenbusStateReconfiguring:
+ read_xenbus_frontend_xdp(be, dev);
+ xenbus_switch_state(dev, XenbusStateReconfigured);
+ break;
+
case XenbusStateClosing:
set_backend_state(be, XenbusStateClosing);
break;
@@ -947,6 +968,8 @@ static int read_xenbus_vif_flags(struct backend_info *be)
vif->ipv6_csum = !!xenbus_read_unsigned(dev->otherend,
"feature-ipv6-csum-offload", 0);
+ read_xenbus_frontend_xdp(be, dev);
+
return 0;
}
@@ -1036,6 +1059,15 @@ static int netback_probe(struct xenbus_device *dev,
goto abort_transaction;
}
+ /* we can adjust a headroom for netfront XDP processing */
+ err = xenbus_printf(xbt, dev->nodename,
+ "feature-xdp-headroom", "%d",
+ provides_xdp_headroom);
+ if (err) {
+ message = "writing feature-xdp-headroom";
+ goto abort_transaction;
+ }
+
/* We don't support rx-flip path (except old guests who
* don't grok this feature flag).
*/
--
1.8.3.1
