On Tue, Dec 20, 2022 at 09:54:48AM -0800, Tony Nguyen wrote:
> From: Maciej Fijalkowski <maciej.fijalkowski@xxxxxxxxx>
>
> Previously ice XDP xmit routine was changed in a way that it avoids
> xdp_buff->xdp_frame conversion as it is simply not needed for handling
> XDP_TX action and what is more it saves us CPU cycles. This routine is
> re-used on ZC driver to handle XDP_TX action.
>
> Although for XDP_TX on Rx ZC xdp_buff that comes from xsk_buff_pool is
> converted to xdp_frame, xdp_frame itself is not stored inside
> ice_tx_buf, we only store raw data pointer. Casting this pointer to
> xdp_frame and calling against it xdp_return_frame in
> ice_clean_xdp_tx_buf() results in undefined behavior.
>
> To fix this, simply call page_frag_free() on tx_buf->raw_buf.
> Later intention is to remove the buff->frame conversion in order to
> simplify the codebase and improve XDP_TX performance on ZC.
>
> Fixes: 126cdfe1007a ("ice: xsk: Improve AF_XDP ZC Tx and use batching API")
> Reported-and-tested-by: Robin Cowley <robin.cowley@xxxxxxxxxxxxxxx>
> Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@xxxxxxxxx>
> Tested-by: Chandan Kumar Rout <chandanx.rout@xxxxxxxxx> (A Contingent Worker at Intel)
> Signed-off-by: Tony Nguyen <anthony.l.nguyen@xxxxxxxxx>
> ---
> drivers/net/ethernet/intel/ice/ice_xsk.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/net/ethernet/intel/ice/ice_xsk.c b/drivers/net/ethernet/intel/ice/ice_xsk.c
> index 907055b77af0..7105de6fb344 100644
> --- a/drivers/net/ethernet/intel/ice/ice_xsk.c
> +++ b/drivers/net/ethernet/intel/ice/ice_xsk.c
> @@ -783,7 +783,7 @@ int ice_clean_rx_irq_zc(struct ice_rx_ring *rx_ring, int budget)
> static void
> ice_clean_xdp_tx_buf(struct ice_tx_ring *xdp_ring, struct ice_tx_buf *tx_buf)
> {
> - xdp_return_frame((struct xdp_frame *)tx_buf->raw_buf);
> + page_frag_free(tx_buf->raw_buf);
> xdp_ring->xdp_tx_active--;
> dma_unmap_single(xdp_ring->dev, dma_unmap_addr(tx_buf, dma),
> dma_unmap_len(tx_buf, len), DMA_TO_DEVICE);
> --
> 2.35.1
>
LGTM
Reviewed-by: Piotr Raczynski <piotr.raczynski@xxxxxxxxxx>
