nfp: bpf: allow control message sizing for map ops

In current ABI the size of the messages carrying map elements was
statically defined to at most 16 words of key and 16 words of value
(NFP word is 4 bytes).  We should not make this assumption and use
the max key and value sizes from the BPF capability instead.

To make sure old kernels don't get surprised with larger (or smaller)
messages bump the FW ABI version to 3 when key/value size is different
than 16 words.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

1 files changed, 3 insertions, 7 deletions

diff --git a/drivers/net/ethernet/netronome/nfp/bpf/fw.h b/drivers/net/ethernet/netronome/nfp/bpf/fw.h
index 58bad868bb6f..813644e90b27 100644
--- a/drivers/net/ethernet/netronome/nfp/bpf/fw.h
+++ b/drivers/net/ethernet/netronome/nfp/bpf/fw.h
@@ -99,6 +99,7 @@ enum nfp_bpf_cmsg_type {
 #define CMSG_TYPE_MAP_REPLY_BIT		7
 #define __CMSG_REPLY(req)		(BIT(CMSG_TYPE_MAP_REPLY_BIT) | (req))
 
+/* BPF ABIv2 fixed-length control message fields */
 #define CMSG_MAP_KEY_LW			16
 #define CMSG_MAP_VALUE_LW		16
 
@@ -148,24 +149,19 @@ struct cmsg_reply_map_free_tbl {
 	__be32 count;
 };
 
-struct cmsg_key_value_pair {
-	__be32 key[CMSG_MAP_KEY_LW];
-	__be32 value[CMSG_MAP_VALUE_LW];
-};
-
 struct cmsg_req_map_op {
 	struct cmsg_hdr hdr;
 	__be32 tid;
 	__be32 count;
 	__be32 flags;
-	struct cmsg_key_value_pair elem[0];
+	u8 data[0];
 };
 
 struct cmsg_reply_map_op {
 	struct cmsg_reply_map_simple reply_hdr;
 	__be32 count;
 	__be32 resv;
-	struct cmsg_key_value_pair elem[0];
+	u8 data[0];
 };
 
 struct cmsg_bpf_event {