xsk: provide sufficient space in pool->tx_descs

The temporary Tx descriptor array in an XSK buffer pool is currently
sized from the Tx ring of the socket that creates the pool.

This is insufficient for shared-UMEM Tx. A later socket may have a
larger Tx ring and submit a valid multi-buffer packet containing more
descriptors than the first socket's ring, while still remaining within
the device's xdp_zc_max_segs limit.

A packet-framed batch parser bounded by the temporary array cannot reach
the end-of-packet descriptor in that case. It leaves the packet on the
Tx ring and encounters the same packet on every subsequent attempt,
stalling Tx processing for that socket.

Size the temporary descriptor array to the larger of the first Tx ring
and the device's xdp_zc_max_segs capability. This keeps the array large
enough to inspect one maximum-sized valid packet. Larger shared Tx rings
do not require further resizing, as they can be processed over multiple
batches.

Following commit will actually address the data path side.

Fixes: d5581966040f ("xsk: support ZC Tx multi-buffer in batch API")
Reviewed-by: Jason Xing <kernelxing@tencent.com>
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20260719135609.147823-4-maciej.fijalkowski@intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

0 files changed, 0 insertions, 0 deletions