On Wed, 14 Apr 2021 23:59:22 +0000 Joseph, Jithu wrote: > On Wed, 2021-04-14 at 16:25 -0700, Jakub Kicinski wrote: > > On Wed, 14 Apr 2021 23:14:04 +0000 Joseph, Jithu wrote: > > > If h/w time-stamp is added by the NIC, then metasize will be non > > > zero > > > (as xdp->data is advanced by the driver ) . h/w ts is still > > > copied > > > into "skb_hwtstamps(skb)->hwtstamp" by the caller of this function > > > igc_dispatch_skb_zc() . Do you still want it to be copied into > > > __skb_put(skb, ) area too ? > > > > If TS is prepended to the frame it should be saved (e.g. on the > > stack) > > before XDP program is called and gets the chance to overwrite it. The > > metadata length when XDP program is called should be 0. > > When you say metadata length should be 0 above, Do you mean that when > bpf_prog_run_xdp(prog, xdp) is invoked, xdp->data and xdp->data_meta > should point to the same address ?
Correct, see xdp_prepare_buff().
