lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Tue, 4 Oct 2022 18:02:56 -0700 From: Stanislav Fomichev <sdf@...gle.com> To: Jakub Kicinski <kuba@...nel.org> Cc: Martin KaFai Lau <martin.lau@...ux.dev>, Jesper Dangaard Brouer <jbrouer@...hat.com>, brouer@...hat.com, bpf@...r.kernel.org, netdev@...r.kernel.org, xdp-hints@...-project.net, larysa.zaremba@...el.com, memxor@...il.com, Lorenzo Bianconi <lorenzo@...nel.org>, mtahhan@...hat.com, Alexei Starovoitov <alexei.starovoitov@...il.com>, Daniel Borkmann <borkmann@...earbox.net>, Andrii Nakryiko <andrii.nakryiko@...il.com>, dave@...cker.co.uk, Magnus Karlsson <magnus.karlsson@...el.com>, bjorn@...nel.org Subject: Re: [PATCH RFCv2 bpf-next 00/18] XDP-hints: XDP gaining access to HW offload hints via BTF On Tue, Oct 4, 2022 at 5:59 PM Jakub Kicinski <kuba@...nel.org> wrote: > > On Tue, 4 Oct 2022 17:25:51 -0700 Martin KaFai Lau wrote: > > A intentionally wild question, what does it take for the driver to return the > > hints. Is the rx_desc and rx_queue enough? When the xdp prog is calling a > > kfunc/bpf-helper, like 'hwtstamp = bpf_xdp_get_hwtstamp()', can the driver > > replace it with some inline bpf code (like how the inline code is generated for > > the map_lookup helper). The xdp prog can then store the hwstamp in the meta > > area in any layout it wants. > > Since you mentioned it... FWIW that was always my preference rather than > the BTF magic :) The jited image would have to be per-driver like we > do for BPF offload but that's easy to do from the technical > perspective (I doubt many deployments bind the same prog to multiple > HW devices).. +1, sounds like a good alternative (got your reply while typing) I'm not too versed in the rx_desc/rx_queue area, but seems like worst case that bpf_xdp_get_hwtstamp can probably receive a xdp_md ctx and parse it out from the pre-populated metadata? Btw, do we also need to think about the redirect case? What happens when I redirect one frame from a device A with one metadata format to a device B with another?
Powered by blists - more mailing lists