diff options
| author | Tirthendu Sarkar <tirthendu.sarkar@intel.com> | 2023-07-19 15:23:59 +0200 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2023-07-19 09:56:48 -0700 |
| commit | 81470b5c3c6649eef8e5f282cd06793f788ae165 (patch) | |
| tree | 4176b6dae1f8642c8ce8a0f320e05f3b357c9806 | |
| parent | 63a64a56bc3f77c74085047ee45356ac850da3e8 (diff) | |
xsk: introduce XSK_USE_SG bind flag for xsk socket
As of now xsk core drops any xdp_buff with data size greater than the
xsk frame_size as set by the af_xdp application. With multi-buffer
support introduced in the next patch xsk core can now split those
buffers into multiple descriptors provided the af_xdp application can
handle them. Such capability of the application needs to be independent
of the xdp_prog's frag support capability since there are cases where
even a single xdp_buffer may need to be split into multiple descriptors
owing to a smaller xsk frame size.
For e.g., with NIC rx_buffer size set to 4kB, a 3kB packet will
constitute of a single buffer and so will be sent as such to AF_XDP layer
irrespective of 'xdp.frags' capability of the XDP program. Now if the xsk
frame size is set to 2kB by the AF_XDP application, then the packet will
need to be split into 2 descriptors if AF_XDP application can handle
multi-buffer, else it needs to be dropped.
Applications can now advertise their frag handling capability to xsk core
so that xsk core can decide if it should drop or split xdp_buffs that
exceed xsk frame size. This is done using a new 'XSK_USE_SG' bind flag
for the xdp socket.
Signed-off-by: Tirthendu Sarkar <tirthendu.sarkar@intel.com>
Link: https://lore.kernel.org/r/20230719132421.584801-3-maciej.fijalkowski@intel.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| -rw-r--r-- | include/net/xdp_sock.h | 1 | ||||
| -rw-r--r-- | include/uapi/linux/if_xdp.h | 6 | ||||
| -rw-r--r-- | net/xdp/xsk.c | 5 |
3 files changed, 10 insertions, 2 deletions
diff --git a/include/net/xdp_sock.h b/include/net/xdp_sock.h index e96a1151ec75..36b0411a0d1b 100644 --- a/include/net/xdp_sock.h +++ b/include/net/xdp_sock.h @@ -52,6 +52,7 @@ struct xdp_sock { struct xsk_buff_pool *pool; u16 queue_id; bool zc; + bool sg; enum { XSK_READY = 0, XSK_BOUND, diff --git a/include/uapi/linux/if_xdp.h b/include/uapi/linux/if_xdp.h index 434f313dc26c..8d48863472b9 100644 --- a/include/uapi/linux/if_xdp.h +++ b/include/uapi/linux/if_xdp.h @@ -25,6 +25,12 @@ * application. */ #define XDP_USE_NEED_WAKEUP (1 << 3) +/* By setting this option, userspace application indicates that it can + * handle multiple descriptors per packet thus enabling AF_XDP to split + * multi-buffer XDP frames into multiple Rx descriptors. Without this set + * such frames will be dropped. + */ +#define XDP_USE_SG (1 << 4) /* Flags for xsk_umem_config flags */ #define XDP_UMEM_UNALIGNED_CHUNK_FLAG (1 << 0) diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c index 914a80cd55d3..7b709e4e7ec4 100644 --- a/net/xdp/xsk.c +++ b/net/xdp/xsk.c @@ -897,7 +897,7 @@ static int xsk_bind(struct socket *sock, struct sockaddr *addr, int addr_len) flags = sxdp->sxdp_flags; if (flags & ~(XDP_SHARED_UMEM | XDP_COPY | XDP_ZEROCOPY | - XDP_USE_NEED_WAKEUP)) + XDP_USE_NEED_WAKEUP | XDP_USE_SG)) return -EINVAL; bound_dev_if = READ_ONCE(sk->sk_bound_dev_if); @@ -929,7 +929,7 @@ static int xsk_bind(struct socket *sock, struct sockaddr *addr, int addr_len) struct socket *sock; if ((flags & XDP_COPY) || (flags & XDP_ZEROCOPY) || - (flags & XDP_USE_NEED_WAKEUP)) { + (flags & XDP_USE_NEED_WAKEUP) || (flags & XDP_USE_SG)) { /* Cannot specify flags for shared sockets. */ err = -EINVAL; goto out_unlock; @@ -1028,6 +1028,7 @@ static int xsk_bind(struct socket *sock, struct sockaddr *addr, int addr_len) xs->dev = dev; xs->zc = xs->umem->zc; + xs->sg = !!(flags & XDP_USE_SG); xs->queue_id = qid; xp_add_xsk(xs->pool, xs); |