* [PATCH bpf-next v6 0/2] Optimize bpf_redirect_map()/xdp_do_redirect()
@ 2021-03-08 11:29 Björn Töpel
2021-03-08 11:29 ` [PATCH bpf-next v6 1/2] bpf, xdp: make bpf_redirect_map() a map operation Björn Töpel
` (3 more replies)
0 siblings, 4 replies; 5+ messages in thread
From: Björn Töpel @ 2021-03-08 11:29 UTC (permalink / raw)
To: ast, daniel, netdev, bpf
Cc: Björn Töpel, bjorn.topel, maciej.fijalkowski, hawk,
toke, magnus.karlsson, john.fastabend, kuba, davem
Hi XDP-folks,
This two patch series contain two optimizations for the
bpf_redirect_map() helper and the xdp_do_redirect() function.
The bpf_redirect_map() optimization is about avoiding the map lookup
dispatching. Instead of having a switch-statement and selecting the
correct lookup function, we let bpf_redirect_map() be a map operation,
where each map has its own bpf_redirect_map() implementation. This way
the run-time lookup is avoided.
The xdp_do_redirect() patch restructures the code, so that the map
pointer indirection can be avoided.
Performance-wise I got 4% improvement for XSKMAP
(sample:xdpsock/rx-drop), and 8% (sample:xdp_redirect_map) on my
machine.
@Jesper/@Toke I kept your Acked-by: for patch 2. Let me know, if you
don't agree with that decision.
More details in each commit.
Changelog:
v5->v6: Removed REDIR enum, and instead use map_id and map_type. (Daniel)
Applied Daniel's fixups on patch 1. (Daniel)
v4->v5: Renamed map operation to map_redirect. (Daniel)
v3->v4: Made bpf_redirect_map() a map operation. (Daniel)
v2->v3: Fix build when CONFIG_NET is not set. (lkp)
v1->v2: Removed warning when CONFIG_BPF_SYSCALL was not set. (lkp)
Cleaned up case-clause in xdp_do_generic_redirect_map(). (Toke)
Re-added comment. (Toke)
rfc->v1: Use map_id, and remove bpf_clear_redirect_map(). (Toke)
Get rid of the macro and use __always_inline. (Jesper)
rfc: https://lore.kernel.org/bpf/87im7fy9nc.fsf@toke.dk/ (Cover not on lore!)
v1: https://lore.kernel.org/bpf/20210219145922.63655-1-bjorn.topel@gmail.com/
v2: https://lore.kernel.org/bpf/20210220153056.111968-1-bjorn.topel@gmail.com/
v3: https://lore.kernel.org/bpf/20210221200954.164125-3-bjorn.topel@gmail.com/
v4: https://lore.kernel.org/bpf/20210226112322.144927-1-bjorn.topel@gmail.com/
v5: https://lore.kernel.org/bpf/20210227122139.183284-1-bjorn.topel@gmail.com/
Björn Töpel (2):
bpf, xdp: make bpf_redirect_map() a map operation
bpf, xdp: restructure redirect actions
include/linux/bpf.h | 26 ++---
include/linux/filter.h | 31 +++++-
include/net/xdp_sock.h | 19 ----
include/trace/events/xdp.h | 62 ++++++-----
kernel/bpf/cpumap.c | 9 +-
kernel/bpf/devmap.c | 17 ++-
kernel/bpf/verifier.c | 13 ++-
net/core/filter.c | 209 ++++++++++++++-----------------------
net/xdp/xskmap.c | 17 ++-
9 files changed, 195 insertions(+), 208 deletions(-)
base-commit: 5e6d87315279db3abe69e2ebfd05fa8f5c014295
--
2.27.0
^ permalink raw reply [flat|nested] 5+ messages in thread
* [PATCH bpf-next v6 1/2] bpf, xdp: make bpf_redirect_map() a map operation
2021-03-08 11:29 [PATCH bpf-next v6 0/2] Optimize bpf_redirect_map()/xdp_do_redirect() Björn Töpel
@ 2021-03-08 11:29 ` Björn Töpel
2021-03-08 11:29 ` [PATCH bpf-next v6 2/2] bpf, xdp: restructure redirect actions Björn Töpel
` (2 subsequent siblings)
3 siblings, 0 replies; 5+ messages in thread
From: Björn Töpel @ 2021-03-08 11:29 UTC (permalink / raw)
To: ast, daniel, netdev, bpf
Cc: Björn Töpel, maciej.fijalkowski, hawk, toke,
magnus.karlsson, john.fastabend, kuba, davem,
Jesper Dangaard Brouer
From: Björn Töpel <bjorn.topel@intel.com>
Currently the bpf_redirect_map() implementation dispatches to the
correct map-lookup function via a switch-statement. To avoid the
dispatching, this change adds bpf_redirect_map() as a map
operation. Each map provides its bpf_redirect_map() version, and
correct function is automatically selected by the BPF verifier.
A nice side-effect of the code movement is that the map lookup
functions are now local to the map implementation files, which removes
one additional function call.
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
---
include/linux/bpf.h | 26 ++++++--------------------
include/linux/filter.h | 27 +++++++++++++++++++++++++++
include/net/xdp_sock.h | 19 -------------------
kernel/bpf/cpumap.c | 8 +++++++-
kernel/bpf/devmap.c | 16 ++++++++++++++--
kernel/bpf/verifier.c | 13 +++++++++++--
net/core/filter.c | 39 +--------------------------------------
net/xdp/xskmap.c | 16 ++++++++++++++++
8 files changed, 82 insertions(+), 82 deletions(-)
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index c931bc97019d..a25730eaa148 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -118,6 +118,9 @@ struct bpf_map_ops {
void *owner, u32 size);
struct bpf_local_storage __rcu ** (*map_owner_storage_ptr)(void *owner);
+ /* Misc helpers.*/
+ int (*map_redirect)(struct bpf_map *map, u32 ifindex, u64 flags);
+
/* map_meta_equal must be implemented for maps that can be
* used as an inner map. It is a runtime check to ensure
* an inner map can be inserted to an outer map.
@@ -1450,9 +1453,9 @@ struct btf *bpf_get_btf_vmlinux(void);
/* Map specifics */
struct xdp_buff;
struct sk_buff;
+struct bpf_dtab_netdev;
+struct bpf_cpu_map_entry;
-struct bpf_dtab_netdev *__dev_map_lookup_elem(struct bpf_map *map, u32 key);
-struct bpf_dtab_netdev *__dev_map_hash_lookup_elem(struct bpf_map *map, u32 key);
void __dev_flush(void);
int dev_xdp_enqueue(struct net_device *dev, struct xdp_buff *xdp,
struct net_device *dev_rx);
@@ -1462,7 +1465,6 @@ int dev_map_generic_redirect(struct bpf_dtab_netdev *dst, struct sk_buff *skb,
struct bpf_prog *xdp_prog);
bool dev_map_can_have_prog(struct bpf_map *map);
-struct bpf_cpu_map_entry *__cpu_map_lookup_elem(struct bpf_map *map, u32 key);
void __cpu_map_flush(void);
int cpu_map_enqueue(struct bpf_cpu_map_entry *rcpu, struct xdp_buff *xdp,
struct net_device *dev_rx);
@@ -1593,17 +1595,6 @@ static inline int bpf_obj_get_user(const char __user *pathname, int flags)
return -EOPNOTSUPP;
}
-static inline struct net_device *__dev_map_lookup_elem(struct bpf_map *map,
- u32 key)
-{
- return NULL;
-}
-
-static inline struct net_device *__dev_map_hash_lookup_elem(struct bpf_map *map,
- u32 key)
-{
- return NULL;
-}
static inline bool dev_map_can_have_prog(struct bpf_map *map)
{
return false;
@@ -1615,6 +1606,7 @@ static inline void __dev_flush(void)
struct xdp_buff;
struct bpf_dtab_netdev;
+struct bpf_cpu_map_entry;
static inline
int dev_xdp_enqueue(struct net_device *dev, struct xdp_buff *xdp,
@@ -1639,12 +1631,6 @@ static inline int dev_map_generic_redirect(struct bpf_dtab_netdev *dst,
return 0;
}
-static inline
-struct bpf_cpu_map_entry *__cpu_map_lookup_elem(struct bpf_map *map, u32 key)
-{
- return NULL;
-}
-
static inline void __cpu_map_flush(void)
{
}
diff --git a/include/linux/filter.h b/include/linux/filter.h
index 3b00fc906ccd..008691fd3b58 100644
--- a/include/linux/filter.h
+++ b/include/linux/filter.h
@@ -1472,4 +1472,31 @@ static inline bool bpf_sk_lookup_run_v6(struct net *net, int protocol,
}
#endif /* IS_ENABLED(CONFIG_IPV6) */
+static __always_inline int __bpf_xdp_redirect_map(struct bpf_map *map, u32 ifindex, u64 flags,
+ void *lookup_elem(struct bpf_map *map, u32 key))
+{
+ struct bpf_redirect_info *ri = this_cpu_ptr(&bpf_redirect_info);
+
+ /* Lower bits of the flags are used as return code on lookup failure */
+ if (unlikely(flags > XDP_TX))
+ return XDP_ABORTED;
+
+ ri->tgt_value = lookup_elem(map, ifindex);
+ if (unlikely(!ri->tgt_value)) {
+ /* If the lookup fails we want to clear out the state in the
+ * redirect_info struct completely, so that if an eBPF program
+ * performs multiple lookups, the last one always takes
+ * precedence.
+ */
+ WRITE_ONCE(ri->map, NULL);
+ return flags;
+ }
+
+ ri->flags = flags;
+ ri->tgt_index = ifindex;
+ WRITE_ONCE(ri->map, map);
+
+ return XDP_REDIRECT;
+}
+
#endif /* __LINUX_FILTER_H__ */
diff --git a/include/net/xdp_sock.h b/include/net/xdp_sock.h
index cc17bc957548..9c0722c6d7ac 100644
--- a/include/net/xdp_sock.h
+++ b/include/net/xdp_sock.h
@@ -80,19 +80,6 @@ int xsk_generic_rcv(struct xdp_sock *xs, struct xdp_buff *xdp);
int __xsk_map_redirect(struct xdp_sock *xs, struct xdp_buff *xdp);
void __xsk_map_flush(void);
-static inline struct xdp_sock *__xsk_map_lookup_elem(struct bpf_map *map,
- u32 key)
-{
- struct xsk_map *m = container_of(map, struct xsk_map, map);
- struct xdp_sock *xs;
-
- if (key >= map->max_entries)
- return NULL;
-
- xs = READ_ONCE(m->xsk_map[key]);
- return xs;
-}
-
#else
static inline int xsk_generic_rcv(struct xdp_sock *xs, struct xdp_buff *xdp)
@@ -109,12 +96,6 @@ static inline void __xsk_map_flush(void)
{
}
-static inline struct xdp_sock *__xsk_map_lookup_elem(struct bpf_map *map,
- u32 key)
-{
- return NULL;
-}
-
#endif /* CONFIG_XDP_SOCKETS */
#endif /* _LINUX_XDP_SOCK_H */
diff --git a/kernel/bpf/cpumap.c b/kernel/bpf/cpumap.c
index 5d1469de6921..7352d4160b7f 100644
--- a/kernel/bpf/cpumap.c
+++ b/kernel/bpf/cpumap.c
@@ -563,7 +563,7 @@ static void cpu_map_free(struct bpf_map *map)
kfree(cmap);
}
-struct bpf_cpu_map_entry *__cpu_map_lookup_elem(struct bpf_map *map, u32 key)
+static void *__cpu_map_lookup_elem(struct bpf_map *map, u32 key)
{
struct bpf_cpu_map *cmap = container_of(map, struct bpf_cpu_map, map);
struct bpf_cpu_map_entry *rcpu;
@@ -600,6 +600,11 @@ static int cpu_map_get_next_key(struct bpf_map *map, void *key, void *next_key)
return 0;
}
+static int cpu_map_redirect(struct bpf_map *map, u32 ifindex, u64 flags)
+{
+ return __bpf_xdp_redirect_map(map, ifindex, flags, __cpu_map_lookup_elem);
+}
+
static int cpu_map_btf_id;
const struct bpf_map_ops cpu_map_ops = {
.map_meta_equal = bpf_map_meta_equal,
@@ -612,6 +617,7 @@ const struct bpf_map_ops cpu_map_ops = {
.map_check_btf = map_check_no_btf,
.map_btf_name = "bpf_cpu_map",
.map_btf_id = &cpu_map_btf_id,
+ .map_redirect = cpu_map_redirect,
};
static void bq_flush_to_queue(struct xdp_bulk_queue *bq)
diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c
index 85d9d1b72a33..f7f42448259f 100644
--- a/kernel/bpf/devmap.c
+++ b/kernel/bpf/devmap.c
@@ -258,7 +258,7 @@ static int dev_map_get_next_key(struct bpf_map *map, void *key, void *next_key)
return 0;
}
-struct bpf_dtab_netdev *__dev_map_hash_lookup_elem(struct bpf_map *map, u32 key)
+static void *__dev_map_hash_lookup_elem(struct bpf_map *map, u32 key)
{
struct bpf_dtab *dtab = container_of(map, struct bpf_dtab, map);
struct hlist_head *head = dev_map_index_hash(dtab, key);
@@ -392,7 +392,7 @@ void __dev_flush(void)
* update happens in parallel here a dev_put wont happen until after reading the
* ifindex.
*/
-struct bpf_dtab_netdev *__dev_map_lookup_elem(struct bpf_map *map, u32 key)
+static void *__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 *obj;
@@ -735,6 +735,16 @@ static int dev_map_hash_update_elem(struct bpf_map *map, void *key, void *value,
map, key, value, map_flags);
}
+static int dev_map_redirect(struct bpf_map *map, u32 ifindex, u64 flags)
+{
+ return __bpf_xdp_redirect_map(map, ifindex, flags, __dev_map_lookup_elem);
+}
+
+static int dev_hash_map_redirect(struct bpf_map *map, u32 ifindex, u64 flags)
+{
+ return __bpf_xdp_redirect_map(map, ifindex, flags, __dev_map_hash_lookup_elem);
+}
+
static int dev_map_btf_id;
const struct bpf_map_ops dev_map_ops = {
.map_meta_equal = bpf_map_meta_equal,
@@ -747,6 +757,7 @@ const struct bpf_map_ops dev_map_ops = {
.map_check_btf = map_check_no_btf,
.map_btf_name = "bpf_dtab",
.map_btf_id = &dev_map_btf_id,
+ .map_redirect = dev_map_redirect,
};
static int dev_map_hash_map_btf_id;
@@ -761,6 +772,7 @@ const struct bpf_map_ops dev_map_hash_ops = {
.map_check_btf = map_check_no_btf,
.map_btf_name = "bpf_dtab",
.map_btf_id = &dev_map_hash_map_btf_id,
+ .map_redirect = dev_hash_map_redirect,
};
static void dev_map_hash_remove_netdev(struct bpf_dtab *dtab,
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 9fe90ce52a65..97eb0b2435b8 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -5582,7 +5582,8 @@ record_func_map(struct bpf_verifier_env *env, struct bpf_call_arg_meta *meta,
func_id != BPF_FUNC_map_push_elem &&
func_id != BPF_FUNC_map_pop_elem &&
func_id != BPF_FUNC_map_peek_elem &&
- func_id != BPF_FUNC_for_each_map_elem)
+ func_id != BPF_FUNC_for_each_map_elem &&
+ func_id != BPF_FUNC_redirect_map)
return 0;
if (map == NULL) {
@@ -12017,7 +12018,8 @@ static int do_misc_fixups(struct bpf_verifier_env *env)
insn->imm == BPF_FUNC_map_delete_elem ||
insn->imm == BPF_FUNC_map_push_elem ||
insn->imm == BPF_FUNC_map_pop_elem ||
- insn->imm == BPF_FUNC_map_peek_elem)) {
+ insn->imm == BPF_FUNC_map_peek_elem ||
+ insn->imm == BPF_FUNC_redirect_map)) {
aux = &env->insn_aux_data[i + delta];
if (bpf_map_ptr_poisoned(aux))
goto patch_call_imm;
@@ -12059,6 +12061,9 @@ static int do_misc_fixups(struct bpf_verifier_env *env)
(int (*)(struct bpf_map *map, void *value))NULL));
BUILD_BUG_ON(!__same_type(ops->map_peek_elem,
(int (*)(struct bpf_map *map, void *value))NULL));
+ BUILD_BUG_ON(!__same_type(ops->map_redirect,
+ (int (*)(struct bpf_map *map, u32 ifindex, u64 flags))NULL));
+
patch_map_ops_generic:
switch (insn->imm) {
case BPF_FUNC_map_lookup_elem:
@@ -12085,6 +12090,10 @@ static int do_misc_fixups(struct bpf_verifier_env *env)
insn->imm = BPF_CAST_CALL(ops->map_peek_elem) -
__bpf_call_base;
continue;
+ case BPF_FUNC_redirect_map:
+ insn->imm = BPF_CAST_CALL(ops->map_redirect) -
+ __bpf_call_base;
+ continue;
}
goto patch_call_imm;
diff --git a/net/core/filter.c b/net/core/filter.c
index 588b19ba0da8..183b0aa6b027 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -3943,22 +3943,6 @@ void xdp_do_flush(void)
}
EXPORT_SYMBOL_GPL(xdp_do_flush);
-static inline void *__xdp_map_lookup_elem(struct bpf_map *map, u32 index)
-{
- switch (map->map_type) {
- case BPF_MAP_TYPE_DEVMAP:
- return __dev_map_lookup_elem(map, index);
- case BPF_MAP_TYPE_DEVMAP_HASH:
- return __dev_map_hash_lookup_elem(map, index);
- case BPF_MAP_TYPE_CPUMAP:
- return __cpu_map_lookup_elem(map, index);
- case BPF_MAP_TYPE_XSKMAP:
- return __xsk_map_lookup_elem(map, index);
- default:
- return NULL;
- }
-}
-
void bpf_clear_redirect_map(struct bpf_map *map)
{
struct bpf_redirect_info *ri;
@@ -4112,28 +4096,7 @@ static const struct bpf_func_proto bpf_xdp_redirect_proto = {
BPF_CALL_3(bpf_xdp_redirect_map, struct bpf_map *, map, u32, ifindex,
u64, flags)
{
- struct bpf_redirect_info *ri = this_cpu_ptr(&bpf_redirect_info);
-
- /* Lower bits of the flags are used as return code on lookup failure */
- if (unlikely(flags > XDP_TX))
- return XDP_ABORTED;
-
- ri->tgt_value = __xdp_map_lookup_elem(map, ifindex);
- if (unlikely(!ri->tgt_value)) {
- /* If the lookup fails we want to clear out the state in the
- * redirect_info struct completely, so that if an eBPF program
- * performs multiple lookups, the last one always takes
- * precedence.
- */
- WRITE_ONCE(ri->map, NULL);
- return flags;
- }
-
- ri->flags = flags;
- ri->tgt_index = ifindex;
- WRITE_ONCE(ri->map, map);
-
- return XDP_REDIRECT;
+ return map->ops->map_redirect(map, ifindex, flags);
}
static const struct bpf_func_proto bpf_xdp_redirect_map_proto = {
diff --git a/net/xdp/xskmap.c b/net/xdp/xskmap.c
index 113fd9017203..fbeb4870f798 100644
--- a/net/xdp/xskmap.c
+++ b/net/xdp/xskmap.c
@@ -125,6 +125,16 @@ static int xsk_map_gen_lookup(struct bpf_map *map, struct bpf_insn *insn_buf)
return insn - insn_buf;
}
+static void *__xsk_map_lookup_elem(struct bpf_map *map, u32 key)
+{
+ struct xsk_map *m = container_of(map, struct xsk_map, map);
+
+ if (key >= map->max_entries)
+ return NULL;
+
+ return READ_ONCE(m->xsk_map[key]);
+}
+
static void *xsk_map_lookup_elem(struct bpf_map *map, void *key)
{
WARN_ON_ONCE(!rcu_read_lock_held());
@@ -215,6 +225,11 @@ static int xsk_map_delete_elem(struct bpf_map *map, void *key)
return 0;
}
+static int xsk_map_redirect(struct bpf_map *map, u32 ifindex, u64 flags)
+{
+ return __bpf_xdp_redirect_map(map, ifindex, flags, __xsk_map_lookup_elem);
+}
+
void xsk_map_try_sock_delete(struct xsk_map *map, struct xdp_sock *xs,
struct xdp_sock **map_entry)
{
@@ -247,4 +262,5 @@ const struct bpf_map_ops xsk_map_ops = {
.map_check_btf = map_check_no_btf,
.map_btf_name = "xsk_map",
.map_btf_id = &xsk_map_btf_id,
+ .map_redirect = xsk_map_redirect,
};
--
2.27.0
^ permalink raw reply related [flat|nested] 5+ messages in thread
* [PATCH bpf-next v6 2/2] bpf, xdp: restructure redirect actions
2021-03-08 11:29 [PATCH bpf-next v6 0/2] Optimize bpf_redirect_map()/xdp_do_redirect() Björn Töpel
2021-03-08 11:29 ` [PATCH bpf-next v6 1/2] bpf, xdp: make bpf_redirect_map() a map operation Björn Töpel
@ 2021-03-08 11:29 ` Björn Töpel
2021-03-10 0:19 ` [PATCH bpf-next v6 0/2] Optimize bpf_redirect_map()/xdp_do_redirect() Daniel Borkmann
2021-03-10 0:20 ` patchwork-bot+netdevbpf
3 siblings, 0 replies; 5+ messages in thread
From: Björn Töpel @ 2021-03-08 11:29 UTC (permalink / raw)
To: ast, daniel, netdev, bpf
Cc: Björn Töpel, maciej.fijalkowski, hawk, toke,
magnus.karlsson, john.fastabend, kuba, davem,
Jesper Dangaard Brouer
From: Björn Töpel <bjorn.topel@intel.com>
The XDP_REDIRECT implementations for maps and non-maps are fairly
similar, but obviously need to take different code paths depending on
if the target is using a map or not. Today, the redirect targets for
XDP either uses a map, or is based on ifindex.
Here, the map type and id are added to bpf_redirect_info, instead of
the actual map. Map type, map item/ifindex, and the map_id (if any) is
passed to xdp_do_redirect().
For ifindex-based redirect, used by the bpf_redirect() XDP BFP helper,
a special map type/id are used. Map type of UNSPEC together with map id
equal to INT_MAX has the special meaning of an ifindex based
redirect. Note that valid map ids are 1 inclusive, INT_MAX exclusive
([1,INT_MAX[).
In addition to making the code easier to follow, using explicit type
and id in bpf_redirect_info has a slight positive performance impact
by avoiding a pointer indirection for the map type lookup, and instead
use the cacheline for bpf_redirect_info.
Since the actual map is not passed via bpf_redirect_info anymore, the
map lookup is only done in the BPF helper. This means that the
bpf_clear_redirect_map() function can be removed. The actual map item
is RCU protected.
The bpf_redirect_info flags member is not used by XDP, and not
read/written any more. The map member is only written to when
required/used, and not unconditionally.
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Reviewed-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
---
include/linux/filter.h | 10 ++-
include/trace/events/xdp.h | 62 ++++++++------
kernel/bpf/cpumap.c | 1 -
kernel/bpf/devmap.c | 1 -
net/core/filter.c | 170 ++++++++++++++++---------------------
net/xdp/xskmap.c | 1 -
6 files changed, 116 insertions(+), 129 deletions(-)
diff --git a/include/linux/filter.h b/include/linux/filter.h
index 008691fd3b58..b2b85b2cad8e 100644
--- a/include/linux/filter.h
+++ b/include/linux/filter.h
@@ -646,7 +646,8 @@ struct bpf_redirect_info {
u32 flags;
u32 tgt_index;
void *tgt_value;
- struct bpf_map *map;
+ u32 map_id;
+ enum bpf_map_type map_type;
u32 kern_flags;
struct bpf_nh_params nh;
};
@@ -1488,13 +1489,14 @@ static __always_inline int __bpf_xdp_redirect_map(struct bpf_map *map, u32 ifind
* performs multiple lookups, the last one always takes
* precedence.
*/
- WRITE_ONCE(ri->map, NULL);
+ ri->map_id = INT_MAX; /* Valid map id idr range: [1,INT_MAX[ */
+ ri->map_type = BPF_MAP_TYPE_UNSPEC;
return flags;
}
- ri->flags = flags;
ri->tgt_index = ifindex;
- WRITE_ONCE(ri->map, map);
+ ri->map_id = map->id;
+ ri->map_type = map->map_type;
return XDP_REDIRECT;
}
diff --git a/include/trace/events/xdp.h b/include/trace/events/xdp.h
index 76a97176ab81..fcad3645a70b 100644
--- a/include/trace/events/xdp.h
+++ b/include/trace/events/xdp.h
@@ -86,19 +86,15 @@ struct _bpf_dtab_netdev {
};
#endif /* __DEVMAP_OBJ_TYPE */
-#define devmap_ifindex(tgt, map) \
- (((map->map_type == BPF_MAP_TYPE_DEVMAP || \
- map->map_type == BPF_MAP_TYPE_DEVMAP_HASH)) ? \
- ((struct _bpf_dtab_netdev *)tgt)->dev->ifindex : 0)
-
DECLARE_EVENT_CLASS(xdp_redirect_template,
TP_PROTO(const struct net_device *dev,
const struct bpf_prog *xdp,
const void *tgt, int err,
- const struct bpf_map *map, u32 index),
+ enum bpf_map_type map_type,
+ u32 map_id, u32 index),
- TP_ARGS(dev, xdp, tgt, err, map, index),
+ TP_ARGS(dev, xdp, tgt, err, map_type, map_id, index),
TP_STRUCT__entry(
__field(int, prog_id)
@@ -111,14 +107,22 @@ DECLARE_EVENT_CLASS(xdp_redirect_template,
),
TP_fast_assign(
+ u32 ifindex = 0, map_index = index;
+
+ if (map_type == BPF_MAP_TYPE_DEVMAP || map_type == BPF_MAP_TYPE_DEVMAP_HASH) {
+ ifindex = ((struct _bpf_dtab_netdev *)tgt)->dev->ifindex;
+ } else if (map_type == BPF_MAP_TYPE_UNSPEC && map_id == INT_MAX) {
+ ifindex = index;
+ map_index = 0;
+ }
+
__entry->prog_id = xdp->aux->id;
__entry->act = XDP_REDIRECT;
__entry->ifindex = dev->ifindex;
__entry->err = err;
- __entry->to_ifindex = map ? devmap_ifindex(tgt, map) :
- index;
- __entry->map_id = map ? map->id : 0;
- __entry->map_index = map ? index : 0;
+ __entry->to_ifindex = ifindex;
+ __entry->map_id = map_id;
+ __entry->map_index = map_index;
),
TP_printk("prog_id=%d action=%s ifindex=%d to_ifindex=%d err=%d"
@@ -133,45 +137,49 @@ DEFINE_EVENT(xdp_redirect_template, xdp_redirect,
TP_PROTO(const struct net_device *dev,
const struct bpf_prog *xdp,
const void *tgt, int err,
- const struct bpf_map *map, u32 index),
- TP_ARGS(dev, xdp, tgt, err, map, index)
+ enum bpf_map_type map_type,
+ u32 map_id, u32 index),
+ TP_ARGS(dev, xdp, tgt, err, map_type, map_id, index)
);
DEFINE_EVENT(xdp_redirect_template, xdp_redirect_err,
TP_PROTO(const struct net_device *dev,
const struct bpf_prog *xdp,
const void *tgt, int err,
- const struct bpf_map *map, u32 index),
- TP_ARGS(dev, xdp, tgt, err, map, index)
+ enum bpf_map_type map_type,
+ u32 map_id, u32 index),
+ TP_ARGS(dev, xdp, tgt, err, map_type, map_id, index)
);
-#define _trace_xdp_redirect(dev, xdp, to) \
- trace_xdp_redirect(dev, xdp, NULL, 0, NULL, to)
+#define _trace_xdp_redirect(dev, xdp, to) \
+ trace_xdp_redirect(dev, xdp, NULL, 0, BPF_MAP_TYPE_UNSPEC, INT_MAX, to)
-#define _trace_xdp_redirect_err(dev, xdp, to, err) \
- trace_xdp_redirect_err(dev, xdp, NULL, err, NULL, to)
+#define _trace_xdp_redirect_err(dev, xdp, to, err) \
+ trace_xdp_redirect_err(dev, xdp, NULL, err, BPF_MAP_TYPE_UNSPEC, INT_MAX, to)
-#define _trace_xdp_redirect_map(dev, xdp, to, map, index) \
- trace_xdp_redirect(dev, xdp, to, 0, map, index)
+#define _trace_xdp_redirect_map(dev, xdp, to, map_type, map_id, index) \
+ trace_xdp_redirect(dev, xdp, to, 0, map_type, map_id, index)
-#define _trace_xdp_redirect_map_err(dev, xdp, to, map, index, err) \
- trace_xdp_redirect_err(dev, xdp, to, err, map, index)
+#define _trace_xdp_redirect_map_err(dev, xdp, to, map_type, map_id, index, err) \
+ trace_xdp_redirect_err(dev, xdp, to, err, map_type, map_id, index)
/* not used anymore, but kept around so as not to break old programs */
DEFINE_EVENT(xdp_redirect_template, xdp_redirect_map,
TP_PROTO(const struct net_device *dev,
const struct bpf_prog *xdp,
const void *tgt, int err,
- const struct bpf_map *map, u32 index),
- TP_ARGS(dev, xdp, tgt, err, map, index)
+ enum bpf_map_type map_type,
+ u32 map_id, u32 index),
+ TP_ARGS(dev, xdp, tgt, err, map_type, map_id, index)
);
DEFINE_EVENT(xdp_redirect_template, xdp_redirect_map_err,
TP_PROTO(const struct net_device *dev,
const struct bpf_prog *xdp,
const void *tgt, int err,
- const struct bpf_map *map, u32 index),
- TP_ARGS(dev, xdp, tgt, err, map, index)
+ enum bpf_map_type map_type,
+ u32 map_id, u32 index),
+ TP_ARGS(dev, xdp, tgt, err, map_type, map_id, index)
);
TRACE_EVENT(xdp_cpumap_kthread,
diff --git a/kernel/bpf/cpumap.c b/kernel/bpf/cpumap.c
index 7352d4160b7f..0cf2791d5099 100644
--- a/kernel/bpf/cpumap.c
+++ b/kernel/bpf/cpumap.c
@@ -543,7 +543,6 @@ static void cpu_map_free(struct bpf_map *map)
* complete.
*/
- bpf_clear_redirect_map(map);
synchronize_rcu();
/* For cpu_map the remote CPUs can still be using the entries
diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c
index f7f42448259f..7a5ad7331c3b 100644
--- a/kernel/bpf/devmap.c
+++ b/kernel/bpf/devmap.c
@@ -197,7 +197,6 @@ static void dev_map_free(struct bpf_map *map)
list_del_rcu(&dtab->list);
spin_unlock(&dev_map_lock);
- bpf_clear_redirect_map(map);
synchronize_rcu();
/* Make sure prior __dev_map_entry_free() have completed. */
diff --git a/net/core/filter.c b/net/core/filter.c
index 183b0aa6b027..b6732000d8a2 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -3918,23 +3918,6 @@ static const struct bpf_func_proto bpf_xdp_adjust_meta_proto = {
.arg2_type = ARG_ANYTHING,
};
-static int __bpf_tx_xdp_map(struct net_device *dev_rx, void *fwd,
- struct bpf_map *map, struct xdp_buff *xdp)
-{
- switch (map->map_type) {
- case BPF_MAP_TYPE_DEVMAP:
- case BPF_MAP_TYPE_DEVMAP_HASH:
- return dev_map_enqueue(fwd, xdp, dev_rx);
- case BPF_MAP_TYPE_CPUMAP:
- return cpu_map_enqueue(fwd, xdp, dev_rx);
- case BPF_MAP_TYPE_XSKMAP:
- return __xsk_map_redirect(fwd, xdp);
- default:
- return -EBADRQC;
- }
- return 0;
-}
-
void xdp_do_flush(void)
{
__dev_flush();
@@ -3943,55 +3926,52 @@ void xdp_do_flush(void)
}
EXPORT_SYMBOL_GPL(xdp_do_flush);
-void bpf_clear_redirect_map(struct bpf_map *map)
-{
- struct bpf_redirect_info *ri;
- int cpu;
-
- for_each_possible_cpu(cpu) {
- ri = per_cpu_ptr(&bpf_redirect_info, cpu);
- /* Avoid polluting remote cacheline due to writes if
- * not needed. Once we pass this test, we need the
- * cmpxchg() to make sure it hasn't been changed in
- * the meantime by remote CPU.
- */
- if (unlikely(READ_ONCE(ri->map) == map))
- cmpxchg(&ri->map, map, NULL);
- }
-}
-
int xdp_do_redirect(struct net_device *dev, struct xdp_buff *xdp,
struct bpf_prog *xdp_prog)
{
struct bpf_redirect_info *ri = this_cpu_ptr(&bpf_redirect_info);
- struct bpf_map *map = READ_ONCE(ri->map);
- u32 index = ri->tgt_index;
+ enum bpf_map_type map_type = ri->map_type;
void *fwd = ri->tgt_value;
+ u32 map_id = ri->map_id;
int err;
- ri->tgt_index = 0;
- ri->tgt_value = NULL;
- WRITE_ONCE(ri->map, NULL);
+ ri->map_id = 0; /* Valid map id idr range: [1,INT_MAX[ */
+ ri->map_type = BPF_MAP_TYPE_UNSPEC;
- if (unlikely(!map)) {
- fwd = dev_get_by_index_rcu(dev_net(dev), index);
- if (unlikely(!fwd)) {
- err = -EINVAL;
- goto err;
+ switch (map_type) {
+ case BPF_MAP_TYPE_DEVMAP:
+ fallthrough;
+ case BPF_MAP_TYPE_DEVMAP_HASH:
+ err = dev_map_enqueue(fwd, xdp, dev);
+ break;
+ case BPF_MAP_TYPE_CPUMAP:
+ err = cpu_map_enqueue(fwd, xdp, dev);
+ break;
+ case BPF_MAP_TYPE_XSKMAP:
+ err = __xsk_map_redirect(fwd, xdp);
+ break;
+ case BPF_MAP_TYPE_UNSPEC:
+ if (map_id == INT_MAX) {
+ fwd = dev_get_by_index_rcu(dev_net(dev), ri->tgt_index);
+ if (unlikely(!fwd)) {
+ err = -EINVAL;
+ break;
+ }
+ err = dev_xdp_enqueue(fwd, xdp, dev);
+ break;
}
-
- err = dev_xdp_enqueue(fwd, xdp, dev);
- } else {
- err = __bpf_tx_xdp_map(dev, fwd, map, xdp);
+ fallthrough;
+ default:
+ err = -EBADRQC;
}
if (unlikely(err))
goto err;
- _trace_xdp_redirect_map(dev, xdp_prog, fwd, map, index);
+ _trace_xdp_redirect_map(dev, xdp_prog, fwd, map_type, map_id, ri->tgt_index);
return 0;
err:
- _trace_xdp_redirect_map_err(dev, xdp_prog, fwd, map, index, err);
+ _trace_xdp_redirect_map_err(dev, xdp_prog, fwd, map_type, map_id, ri->tgt_index, err);
return err;
}
EXPORT_SYMBOL_GPL(xdp_do_redirect);
@@ -4000,41 +3980,36 @@ static int xdp_do_generic_redirect_map(struct net_device *dev,
struct sk_buff *skb,
struct xdp_buff *xdp,
struct bpf_prog *xdp_prog,
- struct bpf_map *map)
+ void *fwd,
+ enum bpf_map_type map_type, u32 map_id)
{
struct bpf_redirect_info *ri = this_cpu_ptr(&bpf_redirect_info);
- u32 index = ri->tgt_index;
- void *fwd = ri->tgt_value;
- int err = 0;
-
- ri->tgt_index = 0;
- ri->tgt_value = NULL;
- WRITE_ONCE(ri->map, NULL);
-
- if (map->map_type == BPF_MAP_TYPE_DEVMAP ||
- map->map_type == BPF_MAP_TYPE_DEVMAP_HASH) {
- struct bpf_dtab_netdev *dst = fwd;
+ int err;
- err = dev_map_generic_redirect(dst, skb, xdp_prog);
+ switch (map_type) {
+ case BPF_MAP_TYPE_DEVMAP:
+ fallthrough;
+ case BPF_MAP_TYPE_DEVMAP_HASH:
+ err = dev_map_generic_redirect(fwd, skb, xdp_prog);
if (unlikely(err))
goto err;
- } else if (map->map_type == BPF_MAP_TYPE_XSKMAP) {
- struct xdp_sock *xs = fwd;
-
- err = xsk_generic_rcv(xs, xdp);
+ break;
+ case BPF_MAP_TYPE_XSKMAP:
+ err = xsk_generic_rcv(fwd, xdp);
if (err)
goto err;
consume_skb(skb);
- } else {
+ break;
+ default:
/* TODO: Handle BPF_MAP_TYPE_CPUMAP */
err = -EBADRQC;
goto err;
}
- _trace_xdp_redirect_map(dev, xdp_prog, fwd, map, index);
+ _trace_xdp_redirect_map(dev, xdp_prog, fwd, map_type, map_id, ri->tgt_index);
return 0;
err:
- _trace_xdp_redirect_map_err(dev, xdp_prog, fwd, map, index, err);
+ _trace_xdp_redirect_map_err(dev, xdp_prog, fwd, map_type, map_id, ri->tgt_index, err);
return err;
}
@@ -4042,31 +4017,34 @@ int xdp_do_generic_redirect(struct net_device *dev, struct sk_buff *skb,
struct xdp_buff *xdp, struct bpf_prog *xdp_prog)
{
struct bpf_redirect_info *ri = this_cpu_ptr(&bpf_redirect_info);
- struct bpf_map *map = READ_ONCE(ri->map);
- u32 index = ri->tgt_index;
- struct net_device *fwd;
- int err = 0;
-
- if (map)
- return xdp_do_generic_redirect_map(dev, skb, xdp, xdp_prog,
- map);
- ri->tgt_index = 0;
- fwd = dev_get_by_index_rcu(dev_net(dev), index);
- if (unlikely(!fwd)) {
- err = -EINVAL;
- goto err;
- }
+ enum bpf_map_type map_type = ri->map_type;
+ void *fwd = ri->tgt_value;
+ u32 map_id = ri->map_id;
+ int err;
- err = xdp_ok_fwd_dev(fwd, skb->len);
- if (unlikely(err))
- goto err;
+ ri->map_id = 0; /* Valid map id idr range: [1,INT_MAX[ */
+ ri->map_type = BPF_MAP_TYPE_UNSPEC;
- skb->dev = fwd;
- _trace_xdp_redirect(dev, xdp_prog, index);
- generic_xdp_tx(skb, xdp_prog);
- return 0;
+ if (map_type == BPF_MAP_TYPE_UNSPEC && map_id == INT_MAX) {
+ fwd = dev_get_by_index_rcu(dev_net(dev), ri->tgt_index);
+ if (unlikely(!fwd)) {
+ err = -EINVAL;
+ goto err;
+ }
+
+ err = xdp_ok_fwd_dev(fwd, skb->len);
+ if (unlikely(err))
+ goto err;
+
+ skb->dev = fwd;
+ _trace_xdp_redirect(dev, xdp_prog, ri->tgt_index);
+ generic_xdp_tx(skb, xdp_prog);
+ return 0;
+ }
+
+ return xdp_do_generic_redirect_map(dev, skb, xdp, xdp_prog, fwd, map_type, map_id);
err:
- _trace_xdp_redirect_err(dev, xdp_prog, index, err);
+ _trace_xdp_redirect_err(dev, xdp_prog, ri->tgt_index, err);
return err;
}
@@ -4077,10 +4055,12 @@ BPF_CALL_2(bpf_xdp_redirect, u32, ifindex, u64, flags)
if (unlikely(flags))
return XDP_ABORTED;
- ri->flags = flags;
+ /* NB! Map type UNSPEC and map_id == INT_MAX (never generated
+ * by map_idr) is used for ifindex based XDP redirect.
+ */
ri->tgt_index = ifindex;
- ri->tgt_value = NULL;
- WRITE_ONCE(ri->map, NULL);
+ ri->map_id = INT_MAX;
+ ri->map_type = BPF_MAP_TYPE_UNSPEC;
return XDP_REDIRECT;
}
diff --git a/net/xdp/xskmap.c b/net/xdp/xskmap.c
index fbeb4870f798..67b4ce504852 100644
--- a/net/xdp/xskmap.c
+++ b/net/xdp/xskmap.c
@@ -87,7 +87,6 @@ static void xsk_map_free(struct bpf_map *map)
{
struct xsk_map *m = container_of(map, struct xsk_map, map);
- bpf_clear_redirect_map(map);
synchronize_net();
bpf_map_area_free(m);
}
--
2.27.0
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH bpf-next v6 0/2] Optimize bpf_redirect_map()/xdp_do_redirect()
2021-03-08 11:29 [PATCH bpf-next v6 0/2] Optimize bpf_redirect_map()/xdp_do_redirect() Björn Töpel
2021-03-08 11:29 ` [PATCH bpf-next v6 1/2] bpf, xdp: make bpf_redirect_map() a map operation Björn Töpel
2021-03-08 11:29 ` [PATCH bpf-next v6 2/2] bpf, xdp: restructure redirect actions Björn Töpel
@ 2021-03-10 0:19 ` Daniel Borkmann
2021-03-10 0:20 ` patchwork-bot+netdevbpf
3 siblings, 0 replies; 5+ messages in thread
From: Daniel Borkmann @ 2021-03-10 0:19 UTC (permalink / raw)
To: Björn Töpel, ast, netdev, bpf
Cc: bjorn.topel, maciej.fijalkowski, hawk, toke, magnus.karlsson,
john.fastabend, kuba, davem
On 3/8/21 12:29 PM, Björn Töpel wrote:
> Hi XDP-folks,
>
> This two patch series contain two optimizations for the
> bpf_redirect_map() helper and the xdp_do_redirect() function.
>
> The bpf_redirect_map() optimization is about avoiding the map lookup
> dispatching. Instead of having a switch-statement and selecting the
> correct lookup function, we let bpf_redirect_map() be a map operation,
> where each map has its own bpf_redirect_map() implementation. This way
> the run-time lookup is avoided.
>
> The xdp_do_redirect() patch restructures the code, so that the map
> pointer indirection can be avoided.
>
> Performance-wise I got 4% improvement for XSKMAP
> (sample:xdpsock/rx-drop), and 8% (sample:xdp_redirect_map) on my
> machine.
>
> @Jesper/@Toke I kept your Acked-by: for patch 2. Let me know, if you
> don't agree with that decision.
>
> More details in each commit.
>
> Changelog:
> v5->v6: Removed REDIR enum, and instead use map_id and map_type. (Daniel)
> Applied Daniel's fixups on patch 1. (Daniel)
> v4->v5: Renamed map operation to map_redirect. (Daniel)
> v3->v4: Made bpf_redirect_map() a map operation. (Daniel)
> v2->v3: Fix build when CONFIG_NET is not set. (lkp)
> v1->v2: Removed warning when CONFIG_BPF_SYSCALL was not set. (lkp)
> Cleaned up case-clause in xdp_do_generic_redirect_map(). (Toke)
> Re-added comment. (Toke)
> rfc->v1: Use map_id, and remove bpf_clear_redirect_map(). (Toke)
> Get rid of the macro and use __always_inline. (Jesper)
Applied, thanks!
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH bpf-next v6 0/2] Optimize bpf_redirect_map()/xdp_do_redirect()
2021-03-08 11:29 [PATCH bpf-next v6 0/2] Optimize bpf_redirect_map()/xdp_do_redirect() Björn Töpel
` (2 preceding siblings ...)
2021-03-10 0:19 ` [PATCH bpf-next v6 0/2] Optimize bpf_redirect_map()/xdp_do_redirect() Daniel Borkmann
@ 2021-03-10 0:20 ` patchwork-bot+netdevbpf
3 siblings, 0 replies; 5+ messages in thread
From: patchwork-bot+netdevbpf @ 2021-03-10 0:20 UTC (permalink / raw)
To: =?utf-8?b?QmrDtnJuIFTDtnBlbCA8Ympvcm4udG9wZWxAZ21haWwuY29tPg==?=
Cc: ast, daniel, netdev, bpf, bjorn.topel, maciej.fijalkowski, hawk,
toke, magnus.karlsson, john.fastabend, kuba, davem
Hello:
This series was applied to bpf/bpf-next.git (refs/heads/master):
On Mon, 8 Mar 2021 12:29:05 +0100 you wrote:
> Hi XDP-folks,
>
> This two patch series contain two optimizations for the
> bpf_redirect_map() helper and the xdp_do_redirect() function.
>
> The bpf_redirect_map() optimization is about avoiding the map lookup
> dispatching. Instead of having a switch-statement and selecting the
> correct lookup function, we let bpf_redirect_map() be a map operation,
> where each map has its own bpf_redirect_map() implementation. This way
> the run-time lookup is avoided.
>
> [...]
Here is the summary with links:
- [bpf-next,v6,1/2] bpf, xdp: make bpf_redirect_map() a map operation
https://git.kernel.org/bpf/bpf-next/c/e6a4750ffe9d
- [bpf-next,v6,2/2] bpf, xdp: restructure redirect actions
https://git.kernel.org/bpf/bpf-next/c/ee75aef23afe
You are awesome, thank you!
--
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2021-03-10 0:21 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-03-08 11:29 [PATCH bpf-next v6 0/2] Optimize bpf_redirect_map()/xdp_do_redirect() Björn Töpel
2021-03-08 11:29 ` [PATCH bpf-next v6 1/2] bpf, xdp: make bpf_redirect_map() a map operation Björn Töpel
2021-03-08 11:29 ` [PATCH bpf-next v6 2/2] bpf, xdp: restructure redirect actions Björn Töpel
2021-03-10 0:19 ` [PATCH bpf-next v6 0/2] Optimize bpf_redirect_map()/xdp_do_redirect() Daniel Borkmann
2021-03-10 0:20 ` patchwork-bot+netdevbpf
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