> -----Original Message-----
> From: Intel-wired-lan <intel-wired-lan-bounces@xxxxxxxxxx> On Behalf Of
> Maciej Fijalkowski
> Sent: Wednesday, April 28, 2021 1:22 AM
> To: intel-wired-lan@xxxxxxxxxxxxxxxx
> Cc: netdev@xxxxxxxxxxxxxxx; bjorn@xxxxxxxxxx; kuba@xxxxxxxxxx;
> bpf@xxxxxxxxxxxxxxx; davem@xxxxxxxxxxxxx; Karlsson, Magnus
> <magnus.karlsson@xxxxxxxxx>
> Subject: [Intel-wired-lan] [PATCH intel-net] ice: track AF_XDP ZC enabled
> queues in bitmap
>
> Commit c7a219048e45 ("ice: Remove xsk_buff_pool from VSI structure")
> silently introduced a regression and broke the Tx side of AF_XDP in copy
> mode. xsk_pool on ice_ring is set only based on the existence of the XDP
> prog on the VSI which in turn picks ice_clean_tx_irq_zc to be executed.
> That is not something that should happen for copy mode as it should use the
> regular data path ice_clean_tx_irq.
>
> This results in a following splat when xdpsock is run in txonly or l2fwd
> scenarios in copy mode:
>
> <snip>
> [ 106.050195] BUG: kernel NULL pointer dereference, address:
> 0000000000000030 [ 106.057269] #PF: supervisor read access in kernel
> mode [ 106.062493] #PF: error_code(0x0000) - not-present page [
> 106.067709] PGD 0 P4D 0 [ 106.070293] Oops: 0000 [#1] PREEMPT SMP
> NOPTI [ 106.074721] CPU: 61 PID: 0 Comm: swapper/61 Not tainted 5.12.0-
> rc2+ #45 [ 106.081436] Hardware name: Intel Corporation
> S2600WFT/S2600WFT, BIOS SE5C620.86B.02.01.0008.031920191559
> 03/19/2019 [ 106.092027] RIP: 0010:xp_raw_get_dma+0x36/0x50 [
> 106.096551] Code: 74 14 48 b8 ff ff ff ff ff ff 00 00 48 21 f0 48 c1 ee 30 48 01
> c6 48 8b 87 90 00 00 00 48 89 f2 81 e6 ff 0f 00 00 48 c1 ea 0c <48> 8b 04 d0 48
> 83 e0 fe 48 01 f0 c3 66 66 2e 0f 1f 84 00 00 00 00 [ 106.115588] RSP:
> 0018:ffffc9000d694e50 EFLAGS: 00010206 [ 106.120893] RAX:
> 0000000000000000 RBX: ffff88984b8c8a00 RCX: ffff889852581800 [
> 106.128137] RDX: 0000000000000006 RSI: 0000000000000000 RDI:
> ffff88984cd8b800 [ 106.135383] RBP: ffff888123b50001 R08:
> ffff889896800000 R09: 0000000000000800 [ 106.142628] R10:
> 0000000000000000 R11: ffffffff826060c0 R12: 00000000000000ff [
> 106.149872] R13: 0000000000000000 R14: 0000000000000040 R15:
> ffff888123b50018 [ 106.157117] FS: 0000000000000000(0000)
> GS:ffff8897e0f40000(0000) knlGS:0000000000000000 [ 106.165332] CS: 0010
> DS: 0000 ES: 0000 CR0: 0000000080050033 [ 106.171163] CR2:
> 0000000000000030 CR3: 000000000560a004 CR4: 00000000007706e0 [
> 106.178408] DR0: 0000000000000000 DR1: 0000000000000000 DR2:
> 0000000000000000 [ 106.185653] DR3: 0000000000000000 DR6:
> 00000000fffe0ff0 DR7: 0000000000000400 [ 106.192898] PKRU: 55555554 [
> 106.195653] Call Trace:
> [ 106.198143] <IRQ>
> [ 106.200196] ice_clean_tx_irq_zc+0x183/0x2a0 [ice] [ 106.205087]
> ice_napi_poll+0x3e/0x590 [ice] [ 106.209356] __napi_poll+0x2a/0x160 [
> 106.212911] net_rx_action+0xd6/0x200 [ 106.216634]
> __do_softirq+0xbf/0x29b [ 106.220274] irq_exit_rcu+0x88/0xc0 [
> 106.223819] common_interrupt+0x7b/0xa0 [ 106.227719] </IRQ> [
> 106.229857] asm_common_interrupt+0x1e/0x40 </snip>
>
> Fix this by introducing the bitmap of queues that are zero-copy enabled,
> where each bit, corresponding to a queue id that xsk pool is being configured
> on, will be set/cleared within ice_xsk_pool_{en,dis}able and checked within
> ice_xsk_pool(). The latter is a function used for deciding which napi poll
> routine is executed.
> Idea is being taken from our other drivers such as i40e and ixbge.
>
> Fixes: c7a219048e45 ("ice: Remove xsk_buff_pool from VSI structure")
> Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@xxxxxxxxx>
> ---
> drivers/net/ethernet/intel/ice/ice.h | 8 +++++---
> drivers/net/ethernet/intel/ice/ice_lib.c | 10 ++++++++++
> drivers/net/ethernet/intel/ice/ice_xsk.c | 3 +++
> 3 files changed, 18 insertions(+), 3 deletions(-)
>
Tested-by: Kiran Bhandare <kiranx.bhandare@xxxxxxxxx> A Contingent Worker at Intel
