[PATCH v21 bpf-next 09/23] bpf: introduce BPF_F_XDP_MB flag in prog_flags loading the ebpf program

[Lorenzo Bianconi <lorenzo@xxxxxxxxxx>]

Introduce BPF_F_XDP_MB and the related field in bpf_prog_aux in order to
notify the driver the loaded program support xdp multi-buffer.

Acked-by: Toke Hoiland-Jorgensen <toke@xxxxxxxxxx>
Acked-by: John Fastabend <john.fastabend@xxxxxxxxx>
Signed-off-by: Lorenzo Bianconi <lorenzo@xxxxxxxxxx>
---
 include/linux/bpf.h            | 1 +
 include/uapi/linux/bpf.h       | 5 +++++
 kernel/bpf/syscall.c           | 4 +++-
 tools/include/uapi/linux/bpf.h | 5 +++++
 4 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 6e947cd91152..8e5ec0839138 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -934,6 +934,7 @@ struct bpf_prog_aux {
 	bool func_proto_unreliable;
 	bool sleepable;
 	bool tail_call_reachable;
+	bool xdp_mb;
 	struct hlist_node tramp_hlist;
 	/* BTF_KIND_FUNC_PROTO for valid attach_btf_id */
 	const struct btf_type *attach_func_proto;
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index b0383d371b9a..4a4f46ffd31d 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -1111,6 +1111,11 @@ enum bpf_link_type {
  */
 #define BPF_F_SLEEPABLE		(1U << 4)
 
+/* If BPF_F_XDP_MB is used in BPF_PROG_LOAD command, the loaded program
+ * fully support xdp multi-buffer
+ */
+#define BPF_F_XDP_MB		(1U << 5)
+
 /* When BPF ldimm64's insn[0].src_reg != 0 then this can have
  * the following extensions:
  *
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index fa4505f9b611..f2d870888ded 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -2217,7 +2217,8 @@ static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr)
 				 BPF_F_ANY_ALIGNMENT |
 				 BPF_F_TEST_STATE_FREQ |
 				 BPF_F_SLEEPABLE |
-				 BPF_F_TEST_RND_HI32))
+				 BPF_F_TEST_RND_HI32 |
+				 BPF_F_XDP_MB))
 		return -EINVAL;
 
 	if (!IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) &&
@@ -2303,6 +2304,7 @@ static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr)
 	prog->aux->dst_prog = dst_prog;
 	prog->aux->offload_requested = !!attr->prog_ifindex;
 	prog->aux->sleepable = attr->prog_flags & BPF_F_SLEEPABLE;
+	prog->aux->xdp_mb = attr->prog_flags & BPF_F_XDP_MB;
 
 	err = security_bpf_prog_alloc(prog->aux);
 	if (err)
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index b0383d371b9a..4a4f46ffd31d 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -1111,6 +1111,11 @@ enum bpf_link_type {
  */
 #define BPF_F_SLEEPABLE		(1U << 4)
 
+/* If BPF_F_XDP_MB is used in BPF_PROG_LOAD command, the loaded program
+ * fully support xdp multi-buffer
+ */
+#define BPF_F_XDP_MB		(1U << 5)
+
 /* When BPF ldimm64's insn[0].src_reg != 0 then this can have
  * the following extensions:
  *
-- 
2.33.1