Messages in this thread | | | From | Jesper Dangaard Brouer <> | Date | Fri, 31 Mar 2023 13:49:15 +0200 | Subject | Re: [PATCH bpf RFC-V3 1/5] xdp: rss hash types representation |
| |
On 30/03/2023 21.08, Jesper Dangaard Brouer wrote: > > On 30/03/2023 21.02, Stanislav Fomichev wrote: >> On Thu, Mar 30, 2023 at 11:56 AM Jesper Dangaard Brouer >>> >>> On 30/03/2023 20.35, Stanislav Fomichev wrote: >>>> On 03/30, Jesper Dangaard Brouer wrote: > [...] >>> [...] >>>>> diff --git a/net/core/xdp.c b/net/core/xdp.c >>>>> index 528d4b37983d..38d2dee16b47 100644 >>>>> --- a/net/core/xdp.c >>>>> +++ b/net/core/xdp.c >>>>> @@ -734,14 +734,22 @@ __bpf_kfunc int >>>>> bpf_xdp_metadata_rx_timestamp(const struct xdp_md *ctx, u64 *tim >>>>> * bpf_xdp_metadata_rx_hash - Read XDP frame RX hash. >>>>> * @ctx: XDP context pointer. >>>>> * @hash: Return value pointer. >>>>> + * @rss_type: Return value pointer for RSS type. >>>>> + * >>>>> + * The RSS hash type (@rss_type) specifies what portion of packet >>>>> headers NIC >>>>> + * hardware were used when calculating RSS hash value. The type >>>>> combinations >>>>> + * are defined via &enum xdp_rss_hash_type and individual bits can >>>>> be decoded >>>>> + * via &enum xdp_rss_type_bits. >>>>> * >>>>> * Return: >>>>> * * Returns 0 on success or ``-errno`` on error. >>>>> * * ``-EOPNOTSUPP`` : means device driver doesn't implement kfunc >>>>> * * ``-ENODATA`` : means no RX-hash available for this frame >>>>> */ >>>>> -__bpf_kfunc int bpf_xdp_metadata_rx_hash(const struct xdp_md *ctx, >>>>> u32 *hash) >>>>> +__bpf_kfunc int bpf_xdp_metadata_rx_hash(const struct xdp_md *ctx, >>>>> u32 *hash, >>>>> + enum xdp_rss_hash_type *rss_type) >>>>> { >>>> [..] >>>> >>>>> + BTF_TYPE_EMIT(enum xdp_rss_type_bits); >>>> nit: Do we still need this with an extra argument? >>>> >>> Yes, unfortunately (compiler optimizes out enum xdp_rss_type_bits). >>> Do notice the difference xdp_rss_type_bits vs xdp_rss_hash_type. >>> We don't need it for "xdp_rss_hash_type" but need it for >>> "xdp_rss_type_bits". > > >> Ah, I missed that. Then why not expose xdp_rss_type_bits? >> Keep xdp_rss_hash_type for internal drivers' tables, and export the >> enum with the bits? > > Great suggestion, xdp_rss_hash_type will be internal for drivers. > I will do that in V4.
I'm running into annoying compiler warnings [-Wenum-conversion] about enum conversions. I'll try to workaround this... The easiest solution seem to be to only have a single enum, that both contains the BIT()s and combinations of bits (for driver usage).
E.g. warning: implicit conversion from 'enum xdp_rss_type_bits' to 'enum xdp_rss_hash_type' [-Wenum-conversion]
| |