[PATCH bpf-next v4 17/18] bpf: offload map memory usage

[Yafang Shao <laoar.shao@gmail.com>]

A new helper is introduced to calculate offload map memory usage. But
currently the memory dynamically allocated in netdev dev_ops, like
nsim_map_update_elem, is not counted. Let's just put it aside now.

Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
---
 include/linux/bpf.h  | 6 ++++++
 kernel/bpf/offload.c | 6 ++++++
 kernel/bpf/syscall.c | 1 +
 3 files changed, 13 insertions(+)

diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 9059520..6792a79 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -2624,6 +2624,7 @@ static inline bool bpf_map_is_offloaded(struct bpf_map *map)
 
 struct bpf_map *bpf_map_offload_map_alloc(union bpf_attr *attr);
 void bpf_map_offload_map_free(struct bpf_map *map);
+u64 bpf_map_offload_map_mem_usage(const struct bpf_map *map);
 int bpf_prog_test_run_syscall(struct bpf_prog *prog,
 			      const union bpf_attr *kattr,
 			      union bpf_attr __user *uattr);
@@ -2695,6 +2696,11 @@ static inline void bpf_map_offload_map_free(struct bpf_map *map)
 {
 }
 
+static inline u64 bpf_map_offload_map_mem_usage(const struct bpf_map *map)
+{
+	return 0;
+}
+
 static inline int bpf_prog_test_run_syscall(struct bpf_prog *prog,
 					    const union bpf_attr *kattr,
 					    union bpf_attr __user *uattr)
diff --git a/kernel/bpf/offload.c b/kernel/bpf/offload.c
index 0c85e06..d9c9f45 100644
--- a/kernel/bpf/offload.c
+++ b/kernel/bpf/offload.c
@@ -563,6 +563,12 @@ void bpf_map_offload_map_free(struct bpf_map *map)
 	bpf_map_area_free(offmap);
 }
 
+u64 bpf_map_offload_map_mem_usage(const struct bpf_map *map)
+{
+	/* The memory dynamically allocated in netdev dev_ops is not counted */
+	return sizeof(struct bpf_offloaded_map);
+}
+
 int bpf_map_offload_lookup_elem(struct bpf_map *map, void *key, void *value)
 {
 	struct bpf_offloaded_map *offmap = map_to_offmap(map);
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 073957c..3532c1e 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -105,6 +105,7 @@ int bpf_check_uarg_tail_zero(bpfptr_t uaddr,
 	.map_alloc = bpf_map_offload_map_alloc,
 	.map_free = bpf_map_offload_map_free,
 	.map_check_btf = map_check_no_btf,
+	.map_mem_usage = bpf_map_offload_map_mem_usage,
 };
 
 static struct bpf_map *find_and_alloc_map(union bpf_attr *attr)
-- 
1.8.3.1