[SRU][B:linux-azure-4.15][PATCH 32/40] bpf: devmap introduce dev_map_enqueue
William Breathitt Gray
william.gray at canonical.com
Mon Nov 2 12:48:48 UTC 2020
From: Jesper Dangaard Brouer <brouer at redhat.com>
BugLink: https://bugs.launchpad.net/bugs/1877654
Functionality is the same, but the ndo_xdp_xmit call is now
simply invoked from inside the devmap.c code.
V2: Fix compile issue reported by kbuild test robot <lkp at intel.com>
V5: Cleanups requested by Daniel
- Newlines before func definition
- Use BUILD_BUG_ON checks
- Remove unnecessary use return value store in dev_map_enqueue
Signed-off-by: Jesper Dangaard Brouer <brouer at redhat.com>
Signed-off-by: Alexei Starovoitov <ast at kernel.org>
(backported commit 67f29e07e131ffa13ea158c259a513f474c7df27)
[ vilhelmgray: context adjustments ]
Signed-off-by: William Breathitt Gray <william.gray at canonical.com>
---
include/linux/bpf.h | 16 +++++++++++++---
include/trace/events/xdp.h | 9 ++++++++-
kernel/bpf/devmap.c | 34 ++++++++++++++++++++++++++++------
net/core/filter.c | 15 ++-------------
4 files changed, 51 insertions(+), 23 deletions(-)
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index e5b17218e70d..788f881a5d99 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -413,14 +413,16 @@ static inline void bpf_long_memcpy(void *dst, const void *src, u32 size)
int bpf_check(struct bpf_prog **fp, union bpf_attr *attr);
/* Map specifics */
-struct net_device *__dev_map_lookup_elem(struct bpf_map *map, u32 key);
+struct xdp_buff;
+
+struct bpf_dtab_netdev *__dev_map_lookup_elem(struct bpf_map *map, u32 key);
void __dev_map_insert_ctx(struct bpf_map *map, u32 index);
void __dev_map_flush(struct bpf_map *map);
+int dev_map_enqueue(struct bpf_dtab_netdev *dst, struct xdp_buff *xdp);
struct bpf_cpu_map_entry *__cpu_map_lookup_elem(struct bpf_map *map, u32 key);
void __cpu_map_insert_ctx(struct bpf_map *map, u32 index);
void __cpu_map_flush(struct bpf_map *map);
-struct xdp_buff;
int cpu_map_enqueue(struct bpf_cpu_map_entry *rcpu, struct xdp_buff *xdp,
struct net_device *dev_rx);
@@ -499,6 +501,15 @@ static inline void __dev_map_flush(struct bpf_map *map)
{
}
+struct xdp_buff;
+struct bpf_dtab_netdev;
+
+static inline
+int dev_map_enqueue(struct bpf_dtab_netdev *dst, struct xdp_buff *xdp)
+{
+ return 0;
+}
+
static inline
struct bpf_cpu_map_entry *__cpu_map_lookup_elem(struct bpf_map *map, u32 key)
{
@@ -513,7 +524,6 @@ static inline void __cpu_map_flush(struct bpf_map *map)
{
}
-struct xdp_buff;
static inline int cpu_map_enqueue(struct bpf_cpu_map_entry *rcpu,
struct xdp_buff *xdp,
struct net_device *dev_rx)
diff --git a/include/trace/events/xdp.h b/include/trace/events/xdp.h
index 8989a92c571a..96104610d40e 100644
--- a/include/trace/events/xdp.h
+++ b/include/trace/events/xdp.h
@@ -138,11 +138,18 @@ DEFINE_EVENT_PRINT(xdp_redirect_template, xdp_redirect_map_err,
__entry->map_id, __entry->map_index)
);
+#ifndef __DEVMAP_OBJ_TYPE
+#define __DEVMAP_OBJ_TYPE
+struct _bpf_dtab_netdev {
+ struct net_device *dev;
+};
+#endif /* __DEVMAP_OBJ_TYPE */
+
#define devmap_ifindex(fwd, map) \
(!fwd ? 0 : \
(!map ? 0 : \
((map->map_type == BPF_MAP_TYPE_DEVMAP) ? \
- ((struct net_device *)fwd)->ifindex : 0)))
+ ((struct _bpf_dtab_netdev *)fwd)->dev->ifindex : 0)))
#define _trace_xdp_redirect_map(dev, xdp, fwd, map, idx) \
trace_xdp_redirect_map(dev, xdp, devmap_ifindex(fwd, map), \
diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c
index 91b1fbe18774..99240806ef71 100644
--- a/kernel/bpf/devmap.c
+++ b/kernel/bpf/devmap.c
@@ -48,13 +48,15 @@
* calls will fail at this point.
*/
#include <linux/bpf.h>
+#include <net/xdp.h>
#include <linux/filter.h>
+#include <trace/events/xdp.h>
#define DEV_CREATE_FLAG_MASK \
(BPF_F_NUMA_NODE | BPF_F_RDONLY | BPF_F_WRONLY)
struct bpf_dtab_netdev {
- struct net_device *dev;
+ struct net_device *dev; /* must be first member, due to tracepoint */
struct bpf_dtab *dtab;
unsigned int bit;
struct rcu_head rcu;
@@ -250,21 +252,38 @@ void __dev_map_flush(struct bpf_map *map)
* update happens in parallel here a dev_put wont happen until after reading the
* ifindex.
*/
-struct net_device *__dev_map_lookup_elem(struct bpf_map *map, u32 key)
+struct bpf_dtab_netdev *__dev_map_lookup_elem(struct bpf_map *map, u32 key)
{
struct bpf_dtab *dtab = container_of(map, struct bpf_dtab, map);
- struct bpf_dtab_netdev *dev;
+ struct bpf_dtab_netdev *obj;
if (key >= map->max_entries)
return NULL;
- dev = READ_ONCE(dtab->netdev_map[key]);
- return dev ? dev->dev : NULL;
+ obj = READ_ONCE(dtab->netdev_map[key]);
+ return obj;
+}
+
+int dev_map_enqueue(struct bpf_dtab_netdev *dst, struct xdp_buff *xdp)
+{
+ struct net_device *dev = dst->dev;
+ struct xdp_frame *xdpf;
+
+ if (!dev->netdev_ops->ndo_xdp_xmit)
+ return -EOPNOTSUPP;
+
+ xdpf = convert_to_xdp_frame(xdp);
+ if (unlikely(!xdpf))
+ return -EOVERFLOW;
+
+ /* TODO: implement a bulking/enqueue step later */
+ return dev->netdev_ops->ndo_xdp_xmit(dev, xdpf);
}
static void *dev_map_lookup_elem(struct bpf_map *map, void *key)
{
- struct net_device *dev = __dev_map_lookup_elem(map, *(u32 *)key);
+ struct bpf_dtab_netdev *obj = __dev_map_lookup_elem(map, *(u32 *)key);
+ struct net_device *dev = dev = obj ? obj->dev : NULL;
return dev ? &dev->ifindex : NULL;
}
@@ -414,6 +433,9 @@ static struct notifier_block dev_map_notifier = {
static int __init dev_map_init(void)
{
+ /* Assure tracepoint shadow struct _bpf_dtab_netdev is in sync */
+ BUILD_BUG_ON(offsetof(struct bpf_dtab_netdev, dev) !=
+ offsetof(struct _bpf_dtab_netdev, dev));
register_netdevice_notifier(&dev_map_notifier);
return 0;
}
diff --git a/net/core/filter.c b/net/core/filter.c
index 24766051dfd6..c660f84b8067 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -2550,20 +2550,9 @@ static int __bpf_tx_xdp_map(struct net_device *dev_rx, void *fwd,
int err;
if (map->map_type == BPF_MAP_TYPE_DEVMAP) {
- struct net_device *dev = fwd;
- struct xdp_frame *xdpf;
+ struct bpf_dtab_netdev *dst = fwd;
- if (!dev->netdev_ops->ndo_xdp_xmit)
- return -EOPNOTSUPP;
-
- xdpf = convert_to_xdp_frame(xdp);
- if (unlikely(!xdpf))
- return -EOVERFLOW;
-
- /* TODO: move to inside map code instead, for bulk support
- * err = dev_map_enqueue(dev, xdp);
- */
- err = dev->netdev_ops->ndo_xdp_xmit(dev, xdpf);
+ err = dev_map_enqueue(dst, xdp);
if (err)
return err;
__dev_map_insert_ctx(map, index);
--
2.25.1
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