>-----Original Message-----
>From: Intel-wired-lan <[email protected]> On Behalf Of
>Fijalkowski, Maciej
>Sent: Wednesday, August 7, 2024 4:23 PM
>To: [email protected]
>Cc: Fijalkowski, Maciej <[email protected]>;
>[email protected]; [email protected]; Nguyen, Anthony L
><[email protected]>; Karlsson, Magnus
><[email protected]>; [email protected]
>Subject: [Intel-wired-lan] [PATCH iwl-net 3/3] ice: fix truesize operations for
>PAGE_SIZE >= 8192
>
>When working on multi-buffer packet on arch that has PAGE_SIZE >= 8192,
>truesize is calculated and stored in xdp_buff::frame_sz per each processed Rx
>buffer. This means that frame_sz will contain the truesize based on last
>received
>buffer, but commit 1dc1a7e7f410 ("ice:
>Centrallize Rx buffer recycling") assumed this value will be constant for each
>buffer, which breaks the page recycling scheme and mess up the way we
>update the page::page_offset.
>
>To fix this, let us work on constant truesize when PAGE_SIZE >= 8192 instead of
>basing this on size of a packet read from Rx descriptor. This way we can
>simplify
>the code and avoid calculating truesize per each received frame and on top of
>that when using xdp_update_skb_shared_info(), current formula for truesize
>update will be valid.
>
>This means ice_rx_frame_truesize() can be removed altogether.
>Furthermore, first call to it within ice_clean_rx_irq() for 4k PAGE_SIZE was
>redundant as xdp_buff::frame_sz is initialized via xdp_init_buff() in
>ice_vsi_cfg_rxq(). This should have been removed at the point where xdp_buff
>struct started to be a member of ice_rx_ring and it was no longer a stack based
>variable.
>
>There are two fixes tags as my understanding is that the first one exposed us
>to
>broken truesize and page_offset handling and then second introduced broken
>skb_shared_info update in ice_{construct,build}_skb().
>
>Reported-and-tested-by: Luiz Capitulino <[email protected]>
>Closes: https://lore.kernel.org/netdev/8f9e2a5c-fd30-4206-9311-
>[email protected]/
>Fixes: 1dc1a7e7f410 ("ice: Centrallize Rx buffer recycling")
>Fixes: 2fba7dc5157b ("ice: Add support for XDP multi-buffer on Rx side")
>Signed-off-by: Maciej Fijalkowski <[email protected]>
>---
> drivers/net/ethernet/intel/ice/ice_base.c | 21 ++++++++++++++-
>drivers/net/ethernet/intel/ice/ice_txrx.c | 33 -----------------------
> 2 files changed, 20 insertions(+), 34 deletions(-)
>
Tested-by: Chandan Kumar Rout <[email protected]> (A Contingent Worker at
Intel)
