by Simon Horman

[permalink] [raw]

Subject: Re: [PATCH bpf V7 4/7] mlx5: bpf_xdp_metadata_rx_hash add xdp rss hash type

On Wed, Apr 12, 2023 at 01:31:18PM +0200, Jesper Dangaard Brouer wrote:
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>
> On 10/04/2023 17.11, Simon Horman wrote:
> > On Sat, Apr 08, 2023 at 09:24:56PM +0200, Jesper Dangaard Brouer wrote:
> > > Update API for bpf_xdp_metadata_rx_hash() with arg for xdp rss hash type
> > > via mapping table.
> > >
> > > The mlx5 hardware can also identify and RSS hash IPSEC. This indicate
> > > hash includes SPI (Security Parameters Index) as part of IPSEC hash.
> > >
> > > Extend xdp core enum xdp_rss_hash_type with IPSEC hash type.
> > >
> > > Fixes: bc8d405b1ba9 ("net/mlx5e: Support RX XDP metadata")
> > > Signed-off-by: Jesper Dangaard Brouer <[email protected]>
> > > Acked-by: Toke Høiland-Jørgensen <[email protected]>
> > > Acked-by: Stanislav Fomichev <[email protected]>
> > > ---
> > > drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c | 60 ++++++++++++++++++++++
> > > include/linux/mlx5/device.h | 14 ++++-
> > > include/net/xdp.h | 2 +
> > > 3 files changed, 73 insertions(+), 3 deletions(-)
> > >
> > > diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c b/drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c
> > > index efe609f8e3aa..97ef1df94d50 100644
> > > --- a/drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c
> > > +++ b/drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c
> > > @@ -34,6 +34,7 @@
> > > #include <net/xdp_sock_drv.h>
> > > #include "en/xdp.h"
> > > #include "en/params.h"
> > > +#include <linux/bitfield.h>
> > >
> > > int mlx5e_xdp_max_mtu(struct mlx5e_params *params, struct mlx5e_xsk_param *xsk)
> > > {
> > > @@ -169,15 +170,72 @@ static int mlx5e_xdp_rx_timestamp(const struct xdp_md *ctx, u64 *timestamp)
> > > return 0;
> > > }
> > >
> > > +/* Mapping HW RSS Type bits CQE_RSS_HTYPE_IP + CQE_RSS_HTYPE_L4 into 4-bits*/
> > > +#define RSS_TYPE_MAX_TABLE 16 /* 4-bits max 16 entries */
> > > +#define RSS_L4 GENMASK(1, 0)
> > > +#define RSS_L3 GENMASK(3, 2) /* Same as CQE_RSS_HTYPE_IP */
> > > +
> > > +/* Valid combinations of CQE_RSS_HTYPE_IP + CQE_RSS_HTYPE_L4 sorted numerical */
> > > +enum mlx5_rss_hash_type {
> > > + RSS_TYPE_NO_HASH = (FIELD_PREP_CONST(RSS_L3, CQE_RSS_IP_NONE) |
> > > + FIELD_PREP_CONST(RSS_L4, CQE_RSS_L4_NONE)),
> > > + RSS_TYPE_L3_IPV4 = (FIELD_PREP_CONST(RSS_L3, CQE_RSS_IPV4) |
> > > + FIELD_PREP_CONST(RSS_L4, CQE_RSS_L4_NONE)),
> > > + RSS_TYPE_L4_IPV4_TCP = (FIELD_PREP_CONST(RSS_L3, CQE_RSS_IPV4) |
> > > + FIELD_PREP_CONST(RSS_L4, CQE_RSS_L4_TCP)),
> > > + RSS_TYPE_L4_IPV4_UDP = (FIELD_PREP_CONST(RSS_L3, CQE_RSS_IPV4) |
> > > + FIELD_PREP_CONST(RSS_L4, CQE_RSS_L4_UDP)),
> > > + RSS_TYPE_L4_IPV4_IPSEC = (FIELD_PREP_CONST(RSS_L3, CQE_RSS_IPV4) |
> > > + FIELD_PREP_CONST(RSS_L4, CQE_RSS_L4_IPSEC)),
> > > + RSS_TYPE_L3_IPV6 = (FIELD_PREP_CONST(RSS_L3, CQE_RSS_IPV6) |
> > > + FIELD_PREP_CONST(RSS_L4, CQE_RSS_L4_NONE)),
> > > + RSS_TYPE_L4_IPV6_TCP = (FIELD_PREP_CONST(RSS_L3, CQE_RSS_IPV6) |
> > > + FIELD_PREP_CONST(RSS_L4, CQE_RSS_L4_TCP)),
> > > + RSS_TYPE_L4_IPV6_UDP = (FIELD_PREP_CONST(RSS_L3, CQE_RSS_IPV6) |
> > > + FIELD_PREP_CONST(RSS_L4, CQE_RSS_L4_UDP)),
> > > + RSS_TYPE_L4_IPV6_IPSEC = (FIELD_PREP_CONST(RSS_L3, CQE_RSS_IPV6) |
> > > + FIELD_PREP_CONST(RSS_L4, CQE_RSS_L4_IPSEC)),
> > > +} mlx5_rss_hash_type;
> >
> > Hi Jesper,
> >
> > Sparse seems confused about 'mlx5_rss_hash_type' on the line above.
> > And I am too. Perhaps it can be removed?
> >
>
> Yes, it can be removed (in V8).
>
> The reason/trick for doing this was to get compiler to create the enum
> symbol, which allowed me to inspect the type using pahole (see cmd
> below). (This will also expose this to BTF, but it isn't actually
> useful to keep around for BTF, so I will remove it in V8.)

Thanks Jesper,

I didn't know that trick :)

> $ pahole -C mlx5_rss_hash_type
> drivers/net/ethernet/mellanox/mlx5/core/en/xdp.o
> enum mlx5_rss_hash_type {
> RSS_TYPE_NO_HASH = 0,
> RSS_TYPE_L3_IPV4 = 4,
> RSS_TYPE_L4_IPV4_TCP = 5,
> RSS_TYPE_L4_IPV4_UDP = 6,
> RSS_TYPE_L4_IPV4_IPSEC = 7,
> RSS_TYPE_L3_IPV6 = 8,
> RSS_TYPE_L4_IPV6_TCP = 9,
> RSS_TYPE_L4_IPV6_UDP = 10,
> RSS_TYPE_L4_IPV6_IPSEC = 11,
> };
>
> This is practical to for reviewers to see if below code is correct:
>
> > +/* Invalid combinations will simply return zero, allows no boundary
> checks */
> > +static const enum xdp_rss_hash_type
> mlx5_xdp_rss_type[RSS_TYPE_MAX_TABLE] = {
> > + [RSS_TYPE_NO_HASH] = XDP_RSS_TYPE_NONE,
> > + [1] = XDP_RSS_TYPE_NONE, /* Implicit zero */
> > + [2] = XDP_RSS_TYPE_NONE, /* Implicit zero */
> > + [3] = XDP_RSS_TYPE_NONE, /* Implicit zero */
> > + [RSS_TYPE_L3_IPV4] = XDP_RSS_TYPE_L3_IPV4,
> > + [RSS_TYPE_L4_IPV4_TCP] = XDP_RSS_TYPE_L4_IPV4_TCP,
> > + [RSS_TYPE_L4_IPV4_UDP] = XDP_RSS_TYPE_L4_IPV4_UDP,
> > + [RSS_TYPE_L4_IPV4_IPSEC] = XDP_RSS_TYPE_L4_IPV4_IPSEC,
> > + [RSS_TYPE_L3_IPV6] = XDP_RSS_TYPE_L3_IPV6,
> > + [RSS_TYPE_L4_IPV6_TCP] = XDP_RSS_TYPE_L4_IPV6_TCP,
> > + [RSS_TYPE_L4_IPV6_UDP] = XDP_RSS_TYPE_L4_IPV6_UDP,
> > + [RSS_TYPE_L4_IPV6_IPSEC] = XDP_RSS_TYPE_L4_IPV6_IPSEC,
> > + [12] = XDP_RSS_TYPE_NONE, /* Implicit zero */
> > + [13] = XDP_RSS_TYPE_NONE, /* Implicit zero */
> > + [14] = XDP_RSS_TYPE_NONE, /* Implicit zero */
> > + [15] = XDP_RSS_TYPE_NONE, /* Implicit zero */
> > +};
>
> > drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c:198:3: warning: symbol 'mlx5_rss_hash_type' was not declared. Should it be static?
> >
> > ...
> >
>