From: Maciej Fijalkowski Date: Thu, 2 Apr 2026 15:49:53 +0000 (+0200) Subject: xsk: fix XDP_UMEM_SG_FLAG issues X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=93e84fe45b752d17a5a46b306ed78f0133bbc719;p=thirdparty%2Fkernel%2Flinux.git xsk: fix XDP_UMEM_SG_FLAG issues Currently xp_assign_dev_shared() is missing XDP_USE_SG being propagated to flags so set it in order to preserve mtu check that is supposed to be done only when no multi-buffer setup is in picture. Also, this flag has the same value as XDP_UMEM_TX_SW_CSUM so we could get unexpected SG setups for software Tx checksums. Since csum flag is UAPI, modify value of XDP_UMEM_SG_FLAG. Fixes: d609f3d228a8 ("xsk: add multi-buffer support for sockets sharing umem") Reviewed-by: Björn Töpel Signed-off-by: Maciej Fijalkowski Link: https://patch.msgid.link/20260402154958.562179-4-maciej.fijalkowski@intel.com Signed-off-by: Jakub Kicinski --- diff --git a/include/net/xdp_sock.h b/include/net/xdp_sock.h index 23e8861e8b25..ebac60a3d8a1 100644 --- a/include/net/xdp_sock.h +++ b/include/net/xdp_sock.h @@ -14,7 +14,7 @@ #include #include -#define XDP_UMEM_SG_FLAG (1 << 1) +#define XDP_UMEM_SG_FLAG BIT(3) struct net_device; struct xsk_queue; diff --git a/net/xdp/xsk_buff_pool.c b/net/xdp/xsk_buff_pool.c index 37b7a68b89b3..729602a3cec0 100644 --- a/net/xdp/xsk_buff_pool.c +++ b/net/xdp/xsk_buff_pool.c @@ -247,6 +247,10 @@ int xp_assign_dev_shared(struct xsk_buff_pool *pool, struct xdp_sock *umem_xs, struct xdp_umem *umem = umem_xs->umem; flags = umem->zc ? XDP_ZEROCOPY : XDP_COPY; + + if (umem->flags & XDP_UMEM_SG_FLAG) + flags |= XDP_USE_SG; + if (umem_xs->pool->uses_need_wakeup) flags |= XDP_USE_NEED_WAKEUP;