Re: XDP multi-buffer and AF_XDP
Jesper Dangaard Brouer <[email protected]>
| Newsgroups | org.kernel.vger.xdp-newbies |
|---|---|
| Message-ID | <[email protected]> |
On 01/04/2022 13.39, Toke Høiland-Jørgensen wrote: > Kal Cutter Conley <[email protected]> writes: > >>> >>> Hi, >>> We are very interested in receiving jumbo frames (> 8000 bytes) over >>> AF_XDP. Does XDP multi-buffer support XDP_REDIRECT with AF_XDP? What >>> about in zero-copy mode? >>> >>> Cheers, >>> Kal >> >> Looking into this more I found this comment in the mlx5 driver: >> >> /* Don't enable multi buffer on XDP_REDIRECT SQ, as it's not yet >> * supported by upstream, and there is no defined trigger to allow >> * transmitting redirected multi-buffer frames. >> */ >> >> So at least mlx5 does not yet support XDP multi-buffer with >> XDP_REDIRECT. What "upstream" support is required to get XDP_REDIRECT >> to work with XSKs? > > Well, the initial patch set for multibuf explicitly blocked XDP_REDIRECT > between interfaces, which is what that comment is referring to (the TX > side). > > For AF_XDP we'd also need to define the UAPI, and maybe add a socket > flag so the userspace program can signal to the kernel that it > understands it? Not sure about the details. > > You're definitely not the only person who wants this, though; adding in > some people who may have a better idea of the exact steps needed. Cc. Eric Sage, as he also expressed interest in implementing this... --Jesper