On Sat, Oct 19, 2019 at 11:48 AM Alexei Starovoitov
<alexei.starovoitov@xxxxxxxxx> wrote:
>
> On Fri, Oct 18, 2019 at 11:33:40AM +0200, Magnus Karlsson wrote:
> > +
> > + #include <linux/bpf.h>
> > + #include "bpf_helpers.h"
> > +
> > + #define MAX_SOCKS 16
> > +
> > + struct {
> > + __uint(type, BPF_MAP_TYPE_XSKMAP);
> > + __uint(max_entries, MAX_SOCKS);
> > + __uint(key_size, sizeof(int));
> > + __uint(value_size, sizeof(int));
> > + } xsks_map SEC(".maps");
> > +
> > + struct {
> > + __uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
> > + __uint(max_entries, 1);
> > + __type(key, int);
> > + __type(value, unsigned int);
> > + } rr_map SEC(".maps");
>
> hmm. does xsks_map compile?
Yes. Actually, I wrote a new sample to demonstrate this feature and to
test the code above. I will send that patch set (contains some small
additions to libbpf also to be able to support this) to bpf-next.
Though, if I used the __type declarations of the rr_map PERCPU_ARRAY I
got this warning: "pr_warning("Error in
bpf_create_map_xattr(%s):%s(%d). Retrying without BTF.\n")", so I had
to change it to the type above that is also used for SOCKMAP. Some
enablement that is missing for XSKMAP? Have not dug into it.
> > +
> > + SEC("xdp_sock") int xdp_sock_prog(struct xdp_md *ctx)
> > + {
> > + int key = 0, idx;
> > + unsigned int *rr;
> > +
> > + rr = bpf_map_lookup_elem(&rr_map, &key);
> > + if (!rr)
> > + return XDP_ABORTED;
>
> could you please use global data and avoid lookup?
> The run-time will be much faster.
Good idea. Will do and change the new sample app too.
