> -----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. > --Jesper
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