Stanislav Fomichev <sdf@xxxxxxxxxx> writes:
> The goal is to enable end-to-end testing of the metadata
> for AF_XDP. Current rx_timestamp kfunc returns current
> time which should be enough to exercise this new functionality.
>
> Cc: John Fastabend <john.fastabend@xxxxxxxxx>
> Cc: David Ahern <dsahern@xxxxxxxxx>
> Cc: Martin KaFai Lau <martin.lau@xxxxxxxxx>
> Cc: Jakub Kicinski <kuba@xxxxxxxxxx>
> Cc: Willem de Bruijn <willemb@xxxxxxxxxx>
> Cc: Jesper Dangaard Brouer <brouer@xxxxxxxxxx>
> Cc: Anatoly Burakov <anatoly.burakov@xxxxxxxxx>
> Cc: Alexander Lobakin <alexandr.lobakin@xxxxxxxxx>
> Cc: Magnus Karlsson <magnus.karlsson@xxxxxxxxx>
> Cc: Maryam Tahhan <mtahhan@xxxxxxxxxx>
> Cc: xdp-hints@xxxxxxxxxxxxxxx
> Cc: netdev@xxxxxxxxxxxxxxx
> Signed-off-by: Stanislav Fomichev <sdf@xxxxxxxxxx>
> ---
> drivers/net/veth.c | 14 ++++++++++++++
> 1 file changed, 14 insertions(+)
>
> diff --git a/drivers/net/veth.c b/drivers/net/veth.c
> index 2a4592780141..c626580a2294 100644
> --- a/drivers/net/veth.c
> +++ b/drivers/net/veth.c
> @@ -25,6 +25,7 @@
> #include <linux/filter.h>
> #include <linux/ptr_ring.h>
> #include <linux/bpf_trace.h>
> +#include <linux/bpf_patch.h>
> #include <linux/net_tstamp.h>
>
> #define DRV_NAME "veth"
> @@ -1659,6 +1660,18 @@ static int veth_xdp(struct net_device *dev, struct netdev_bpf *xdp)
> }
> }
>
> +static void veth_unroll_kfunc(const struct bpf_prog *prog, u32 func_id,
> + struct bpf_patch *patch)
> +{
> + if (func_id == xdp_metadata_kfunc_id(XDP_METADATA_KFUNC_RX_TIMESTAMP_SUPPORTED)) {
> + /* return true; */
> + bpf_patch_append(patch, BPF_MOV64_IMM(BPF_REG_0, 1));
> + } else if (func_id == xdp_metadata_kfunc_id(XDP_METADATA_KFUNC_RX_TIMESTAMP)) {
> + /* return ktime_get_mono_fast_ns(); */
> + bpf_patch_append(patch, BPF_EMIT_CALL(ktime_get_mono_fast_ns));
> + }
> +}
So these look reasonable enough, but would be good to see some examples
of kfunc implementations that don't just BPF_CALL to a kernel function
(with those helper wrappers we were discussing before).
-Toke
