On Fri, Apr 01, 2022 at 01:26:12PM +0000, Karlsson, Magnus wrote: > > > > -----Original Message----- > > From: Jesper Dangaard Brouer <jbrouer@xxxxxxxxxx> > > Sent: Friday, April 1, 2022 3:13 PM > > To: Toke Høiland-Jørgensen <toke@xxxxxxxxxx>; Kal Cutter Conley > > <kal.conley@xxxxxxxxxxx>; Xdp <xdp-newbies@xxxxxxxxxxxxxxx> > > Cc: Brouer, Jesper <brouer@xxxxxxxxxx>; Lorenzo Bianconi > > <lorenzo.bianconi@xxxxxxxxxx>; Karlsson, Magnus > > <magnus.karlsson@xxxxxxxxx>; eric.david.sage@xxxxxxxxx > > Subject: Re: XDP multi-buffer and AF_XDP > > > > > > On 01/04/2022 13.39, Toke Høiland-Jørgensen wrote: > > > Kal Cutter Conley <kal.conley@xxxxxxxxxxx> 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... > > Adding Tirtha that has patches for the AF_XDP support of multi-buffer. Though, he is currently integrating his i40e multi-buffer driver support with Lorenzo's TX-patches that he sent as an RFC. Latest I heard is that Tirtha is planning on submitting this in a couple of weeks as a proper patch to the mailing list. And after that, the focus is to brush up the AF_XDP and ZC support patches as we stopped trying to track Lorenzo's multi-buffer patches at version 13 out of 23 ;-). We just could not keep up. Ah, if there is anything I can do to help please let me know. My company needs this feature so I can work on it full time. I would love to help out however I can. Thanks, Eric Sage > > > --Jesper >
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