@@ -55,10 +55,17 @@
#define DEV_CREATE_FLAG_MASK \
(BPF_F_NUMA_NODE | BPF_F_RDONLY | BPF_F_WRONLY)
+#define DEV_MAP_BULK_SIZE 16
+struct xdp_bulk_queue {
+ struct xdp_frame *q[DEV_MAP_BULK_SIZE];
+ unsigned int count;
+};
+
struct bpf_dtab_netdev {
struct net_device *dev; /* must be first member, due to tracepoint */
struct bpf_dtab *dtab;
unsigned int bit;
+ struct xdp_bulk_queue __percpu *bulkq;
struct rcu_head rcu;
};
@@ -217,6 +224,34 @@ void __dev_map_insert_ctx(struct bpf_map *map, u32 bit)
__set_bit(bit, bitmap);
}
+static int bq_xmit_all(struct bpf_dtab_netdev *obj,
+ struct xdp_bulk_queue *bq)
+{
+ struct net_device *dev = obj->dev;
+ int i;
+
+ if (unlikely(!bq->count))
+ return 0;
+
+ for (i = 0; i < bq->count; i++) {
+ struct xdp_frame *xdpf = bq->q[i];
+
+ prefetch(xdpf);
+ }
+
+ for (i = 0; i < bq->count; i++) {
+ struct xdp_frame *xdpf = bq->q[i];
+ int err;
+
+ err = dev->netdev_ops->ndo_xdp_xmit(dev, xdpf);
+ if (err)
+ xdp_return_frame(xdpf);
+ }
+ bq->count = 0;
+
+ return 0;
+}
+
/* __dev_map_flush is called from xdp_do_flush_map() which _must_ be signaled
* from the driver before returning from its napi->poll() routine. The poll()
* routine is called either from busy_poll context or net_rx_action signaled
@@ -232,6 +267,7 @@ void __dev_map_flush(struct bpf_map *map)
for_each_set_bit(bit, bitmap, map->max_entries) {
struct bpf_dtab_netdev *dev = READ_ONCE(dtab->netdev_map[bit]);
+ struct xdp_bulk_queue *bq;
struct net_device *netdev;
/* This is possible if the dev entry is removed by user space
@@ -240,6 +276,8 @@ void __dev_map_flush(struct bpf_map *map)
if (unlikely(!dev))
continue;
+ bq = this_cpu_ptr(dev->bulkq);
+ bq_xmit_all(dev, bq);
netdev = dev->dev;
if (likely(netdev->netdev_ops->ndo_xdp_flush))
netdev->netdev_ops->ndo_xdp_flush(netdev);
@@ -264,6 +302,20 @@ struct bpf_dtab_netdev *__dev_map_lookup_elem(struct bpf_map *map, u32 key)
return obj;
}
+/* Runs under RCU-read-side, plus in softirq under NAPI protection.
+ * Thus, safe percpu variable access.
+ */
+static int bq_enqueue(struct bpf_dtab_netdev *obj, struct xdp_frame *xdpf)
+{
+ struct xdp_bulk_queue *bq = this_cpu_ptr(obj->bulkq);
+
+ if (unlikely(bq->count == DEV_MAP_BULK_SIZE))
+ bq_xmit_all(obj, bq);
+
+ bq->q[bq->count++] = xdpf;
+ return 0;
+}
+
int dev_map_enqueue(struct bpf_dtab_netdev *dst, struct xdp_buff *xdp)
{
struct net_device *dev = dst->dev;
@@ -276,8 +328,7 @@ int dev_map_enqueue(struct bpf_dtab_netdev *dst, struct xdp_buff *xdp)
if (unlikely(!xdpf))
return -EOVERFLOW;
- /* TODO: implement a bulking/enqueue step later */
- return dev->netdev_ops->ndo_xdp_xmit(dev, xdpf);
+ return bq_enqueue(dst, xdpf);
}
static void *dev_map_lookup_elem(struct bpf_map *map, void *key)
@@ -292,13 +343,18 @@ static void dev_map_flush_old(struct bpf_dtab_netdev *dev)
{
if (dev->dev->netdev_ops->ndo_xdp_flush) {
struct net_device *fl = dev->dev;
+ struct xdp_bulk_queue *bq;
unsigned long *bitmap;
+
int cpu;
for_each_online_cpu(cpu) {
bitmap = per_cpu_ptr(dev->dtab->flush_needed, cpu);
__clear_bit(dev->bit, bitmap);
+ bq = per_cpu_ptr(dev->bulkq, cpu);
+ bq_xmit_all(dev, bq);
+
fl->netdev_ops->ndo_xdp_flush(dev->dev);
}
}
@@ -310,6 +366,7 @@ static void __dev_map_entry_free(struct rcu_head *rcu)
dev = container_of(rcu, struct bpf_dtab_netdev, rcu);
dev_map_flush_old(dev);
+ free_percpu(dev->bulkq);
dev_put(dev->dev);
kfree(dev);
}
@@ -342,6 +399,7 @@ static int dev_map_update_elem(struct bpf_map *map, void *key, void *value,
{
struct bpf_dtab *dtab = container_of(map, struct bpf_dtab, map);
struct net *net = current->nsproxy->net_ns;
+ gfp_t gfp = GFP_ATOMIC | __GFP_NOWARN;
struct bpf_dtab_netdev *dev, *old_dev;
u32 i = *(u32 *)key;
u32 ifindex = *(u32 *)value;
@@ -356,13 +414,20 @@ static int dev_map_update_elem(struct bpf_map *map, void *key, void *value,
if (!ifindex) {
dev = NULL;
} else {
- dev = kmalloc_node(sizeof(*dev), GFP_ATOMIC | __GFP_NOWARN,
- map->numa_node);
+ dev = kmalloc_node(sizeof(*dev), gfp, map->numa_node);
if (!dev)
return -ENOMEM;
+ dev->bulkq = __alloc_percpu_gfp(sizeof(*dev->bulkq),
+ sizeof(void *), gfp);
+ if (!dev->bulkq) {
+ kfree(dev);
+ return -ENOMEM;
+ }
+
dev->dev = dev_get_by_index(net, ifindex);
if (!dev->dev) {
+ free_percpu(dev->bulkq);
kfree(dev);
return -EINVAL;
}