On Wed, 12 Jun 2019 at 20:05, Maxim Mikityanskiy <maximmi@xxxxxxxxxxxx> wrote:
>
> Query XDP_OPTIONS in libbpf to determine if the zero-copy mode is active
> or not.
>
Acked-by: Björn Töpel <bjorn.topel@xxxxxxxxx>
> Signed-off-by: Maxim Mikityanskiy <maximmi@xxxxxxxxxxxx>
> Reviewed-by: Tariq Toukan <tariqt@xxxxxxxxxxxx>
> Acked-by: Saeed Mahameed <saeedm@xxxxxxxxxxxx>
> ---
> tools/lib/bpf/xsk.c | 12 ++++++++++++
> 1 file changed, 12 insertions(+)
>
> diff --git a/tools/lib/bpf/xsk.c b/tools/lib/bpf/xsk.c
> index 7ef6293b4fd7..bf15a80a37c2 100644
> --- a/tools/lib/bpf/xsk.c
> +++ b/tools/lib/bpf/xsk.c
> @@ -65,6 +65,7 @@ struct xsk_socket {
> int xsks_map_fd;
> __u32 queue_id;
> char ifname[IFNAMSIZ];
> + bool zc;
> };
>
> struct xsk_nl_info {
> @@ -480,6 +481,7 @@ int xsk_socket__create(struct xsk_socket **xsk_ptr, const char *ifname,
> void *rx_map = NULL, *tx_map = NULL;
> struct sockaddr_xdp sxdp = {};
> struct xdp_mmap_offsets off;
> + struct xdp_options opts;
> struct xsk_socket *xsk;
> socklen_t optlen;
> int err;
> @@ -597,6 +599,16 @@ int xsk_socket__create(struct xsk_socket **xsk_ptr, const char *ifname,
> }
>
> xsk->prog_fd = -1;
> +
> + optlen = sizeof(opts);
> + err = getsockopt(xsk->fd, SOL_XDP, XDP_OPTIONS, &opts, &optlen);
> + if (err) {
> + err = -errno;
> + goto out_mmap_tx;
> + }
> +
> + xsk->zc = opts.flags & XDP_OPTIONS_ZEROCOPY;
> +
> if (!(xsk->config.libbpf_flags & XSK_LIBBPF_FLAGS__INHIBIT_PROG_LOAD)) {
> err = xsk_setup_xdp_prog(xsk);
> if (err)
> --
> 2.19.1
>
