On 5/28/20 4:25 AM, Jesper Dangaard Brouer wrote:
> That said, you should use the new SEC(".maps") definitions, but you
> need to use some tricks to avoid a BTF-ID getting generated. Let me
> help you with something that should work:
>
> /* DEVMAP values */
> struct devmap_val {
> __u32 ifindex; /* device index */
> };
>
> struct {
> __uint(type, BPF_MAP_TYPE_DEVMAP);
> __uint(key_size, sizeof(u32));
> __uint(value_size, sizeof(struct devmap_val));
> __uint(max_entries, 4);
> } dm_ports SEC(".maps");
>
> Notice by setting key_size and value_size, instead of the "__type",
> then a BTF-ID will be generated for this map.
> Normally with proper BTF it should look like:
>
> struct {
> __uint(type, BPF_MAP_TYPE_DEVMAP);
> __type(key, u32);
> __type(value, struct devmap_val);
> __uint(max_entries, 4);
> } dm_ports_with_BTF SEC(".maps");
>
>
Thanks for the tip.
