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:
[...]
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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]
