| Message ID | 20210427195209.54217-1-maciej.fijalkowski@intel.com (mailing list archive) |
|---|---|
| State | Awaiting Upstream |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [intel-net] ice: track AF_XDP ZC enabled queues in bitmap | expand |
> -----Original Message----- > From: Intel-wired-lan <intel-wired-lan-bounces@osuosl.org> On Behalf Of > Maciej Fijalkowski > Sent: Wednesday, April 28, 2021 1:22 AM > To: intel-wired-lan@lists.osuosl.org > Cc: netdev@vger.kernel.org; bjorn@kernel.org; kuba@kernel.org; > bpf@vger.kernel.org; davem@davemloft.net; Karlsson, Magnus > <magnus.karlsson@intel.com> > 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@intel.com> > --- > 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@intel.com> A Contingent Worker at Intel
diff --git a/drivers/net/ethernet/intel/ice/ice.h b/drivers/net/ethernet/intel/ice/ice.h index 02badaaf818c..a63a13edf365 100644 --- a/drivers/net/ethernet/intel/ice/ice.h +++ b/drivers/net/ethernet/intel/ice/ice.h @@ -331,6 +331,7 @@ struct ice_vsi { struct ice_tc_cfg tc_cfg; struct bpf_prog *xdp_prog; struct ice_ring **xdp_rings; /* XDP ring array */ + unsigned long *af_xdp_zc_qps; /* tracks AF_XDP ZC enabled qps */ u16 num_xdp_txq; /* Used XDP queues */ u8 xdp_mapping_mode; /* ICE_MAP_MODE_[CONTIG|SCATTER] */ @@ -540,15 +541,16 @@ static inline void ice_set_ring_xdp(struct ice_ring *ring) */ static inline struct xsk_buff_pool *ice_xsk_pool(struct ice_ring *ring) { + struct ice_vsi *vsi = ring->vsi; u16 qid = ring->q_index; if (ice_ring_is_xdp(ring)) - qid -= ring->vsi->num_xdp_txq; + qid -= vsi->num_xdp_txq; - if (!ice_is_xdp_ena_vsi(ring->vsi)) + if (!ice_is_xdp_ena_vsi(vsi) || !test_bit(qid, vsi->af_xdp_zc_qps)) return NULL; - return xsk_get_pool_from_qid(ring->vsi->netdev, qid); + return xsk_get_pool_from_qid(vsi->netdev, qid); } /** diff --git a/drivers/net/ethernet/intel/ice/ice_lib.c b/drivers/net/ethernet/intel/ice/ice_lib.c index 6041ca2830de..44e1233e1e28 100644 --- a/drivers/net/ethernet/intel/ice/ice_lib.c +++ b/drivers/net/ethernet/intel/ice/ice_lib.c @@ -105,8 +105,14 @@ static int ice_vsi_alloc_arrays(struct ice_vsi *vsi) if (!vsi->q_vectors) goto err_vectors; + vsi->af_xdp_zc_qps = bitmap_zalloc(max_t(int, vsi->alloc_txq, vsi->alloc_rxq), GFP_KERNEL); + if (!vsi->af_xdp_zc_qps) + goto err_zc_qps; + return 0; +err_zc_qps: + devm_kfree(dev, vsi->q_vectors); err_vectors: devm_kfree(dev, vsi->rxq_map); err_rxq_map: @@ -286,6 +292,10 @@ static void ice_vsi_free_arrays(struct ice_vsi *vsi) dev = ice_pf_to_dev(pf); + if (vsi->af_xdp_zc_qps) { + bitmap_free(vsi->af_xdp_zc_qps); + vsi->af_xdp_zc_qps = NULL; + } /* free the ring and vector containers */ if (vsi->q_vectors) { devm_kfree(dev, vsi->q_vectors); diff --git a/drivers/net/ethernet/intel/ice/ice_xsk.c b/drivers/net/ethernet/intel/ice/ice_xsk.c index 17ab8ef024ad..adb2f12bcb87 100644 --- a/drivers/net/ethernet/intel/ice/ice_xsk.c +++ b/drivers/net/ethernet/intel/ice/ice_xsk.c @@ -273,6 +273,7 @@ static int ice_xsk_pool_disable(struct ice_vsi *vsi, u16 qid) if (!pool) return -EINVAL; + clear_bit(qid, vsi->af_xdp_zc_qps); xsk_pool_dma_unmap(pool, ICE_RX_DMA_ATTR); return 0; @@ -303,6 +304,8 @@ ice_xsk_pool_enable(struct ice_vsi *vsi, struct xsk_buff_pool *pool, u16 qid) if (err) return err; + set_bit(qid, vsi->af_xdp_zc_qps); + return 0; }
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@intel.com> --- 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(-)