On Mon, Dec 6, 2021 at 11:11 AM Jesper Dangaard Brouer <jbrouer@xxxxxxxxxx> wrote: > > On 30/11/2021 12.53, Lorenzo Bianconi wrote: > > XDP_REDIRECT is not fully supported yet for xdp multi-buff since not > > all XDP capable drivers can map non-linear xdp_frame in ndo_xdp_xmit > > so disable it for the moment. > > > > Signed-off-by: Lorenzo Bianconi <lorenzo@xxxxxxxxxx> > > --- > > net/core/filter.c | 7 +++++++ > > 1 file changed, 7 insertions(+) > > > > diff --git a/net/core/filter.c b/net/core/filter.c > > index b70725313442..a87d835d1122 100644 > > --- a/net/core/filter.c > > +++ b/net/core/filter.c > > @@ -4189,6 +4189,13 @@ int xdp_do_redirect(struct net_device *dev, struct xdp_buff *xdp, > > struct bpf_map *map; > > int err; > > > > + /* XDP_REDIRECT is not fully supported yet for xdp multi-buff since > > + * not all XDP capable drivers can map non-linear xdp_frame in > > + * ndo_xdp_xmit. > > + */ > > + if (unlikely(xdp_buff_is_mb(xdp))) > > + return -EOPNOTSUPP; > > + > > This approach also exclude 'cpumap' use-case, which you AFAIK have added > MB support for in this patchset. > > Generally this check is hopefully something we can remove again, once > drivers add MB ndo_xdp_xmit support. > What happens in the future when a new driver is added without (in its intial version) MB ndo_xdp_xmit support? Is MB support for ndo_xdp_xmit going to be a requirement for a driver (with ndo_xdp_xmit) to be accepted to the kernel? I'm not arguing against removing this check in the future, I'm just wondering if we need a different mechanism than outright prohibiting XDP_REDIRECT with MB to protect against the redirected device not having MB support? > > > ri->map_id = 0; /* Valid map id idr range: [1,INT_MAX[ */ > > ri->map_type = BPF_MAP_TYPE_UNSPEC; > > > > >
