Re: ICE + XSK ZC - page faults on 6.1 LTS when process exits?

[Maciej Fijalkowski <maciej.fijalkowski@intel.com>]

On Fri, Aug 23, 2024 at 10:17:35AM +0200, Magnus Karlsson wrote:
> On Thu, 22 Aug 2024 at 18:25, Alasdair McWilliam
> <alasdair.mcwilliam@outlook.com> wrote:
> >
> > Hi,
> >
> > I've been testing apps that use XSK+ZC on ICE with newer builds of the 6.1 LTS kernel in preparation for some production upgrades, and I've started to notice some instability on newer versions. I can reproduce the issue easily in the lab.
> >
> > Config:
> > - Known good multi-threaded application (i.e. production grade)
> > - Uses eBPF and AF_XDP with zero copy to act as 'bump in wire' in network
> > - Xeon's with Intel E810-CQDA2 (firmware: 3.20 0x8000d83e 1.3146.0)
> > - Effectively a vanilla rebuild of 6.1 using configs from el-repo project
> >
> > Scenario:
> > - Noticing hard kernel faults when shutting down application
> > - Can happen if the process is shut down via systemctl stop
> > - Can even happen with a simple kill -9 command to the PID
> > - Appears in builds after 6.1.87
> >
> > Tested kernels:
> > - 6.1.84: process exits smoothly
> > - 6.1.87: process exits smoothly
> > - 6.1.97: BUG: unable to handle page fault for address
> > - 6.1.106: BUG: unable to handle page fault for address
> >
> > Kdump log is below [1] from 6.1.106 but does seem to be the same in the earlier version.
> >
> > Can anyone advise if this is a known issue?
> >
> > I don't have any builds between 6.1.87 and 6.1.97 but I can spend some time trying to pinpoint the exact version things start to go wrong in, if it would help anyone better equipped than me to debug!
> 
> Hi Alasdair,
> 
> It would be of great help if you could pinpoint the exact version for
> this breakage. Hopefully we could then find the commit in the ice
> driver that breaks your app, since there should be just a handful of
> commits in the ice driver for any stable release.

$ git log --oneline v6.1.87..v6.1.97 drivers/net/ethernet/intel/ice/
dd37b86999fd ice: Fix VSI list rule with ICE_SW_LKUP_LAST type
224b69e8751c ice: avoid IRQ collision to fix init failure on ACPI S3 resume
531d85b4fb66 ice: move RDMA init to ice_idc.c
a62c50545b4d ice: remove af_xdp_zc_qps bitmap
447a5433bd1e ice: remove null checks before devm_kfree() calls
a388961be5ed ice: Introduce new parameters in ice_sched_node
17ccdebe5ac7 ice: fix iteration of TLVs in Preserved Fields Area
07cbc5512023 ice: fix accounting if a VLAN already exists
5ef3a27c6142 ice: Interpret .set_channels() input differently
90cbd4c081bb ice: remove unnecessary duplicate checks for VF VSI ID
59161a21cae0 ice: pass VSI pointer into ice_vc_isvalid_q_id
6a6ebec40820 ice: tc: allow zero flags in parsing tc flower

can you revert a62c50545b4d and see if the issue persists?

> 
> > Kind regards
> > Alasdair
> >
> > [1] kdump log
> >
> > [  158.666867] BUG: unable to handle page fault for address: ffffa6510e5580c0
> > [  158.666887] #PF: supervisor read access in kernel mode
> > [  158.666896] #PF: error_code(0x0000) - not-present page
> > [  158.666903] PGD 100000067 P4D 100000067 PUD 106dc4067 PMD 0
> > [  158.666914] Oops: 0000 [#1] PREEMPT SMP PTI
> > [  158.666922] CPU: 7 PID: 1808 Comm: tlndd.bin Kdump: loaded Tainted: G            E      6.1.106-1.X.el9.x86_64 #1
> > [  158.666940] Hardware name: Supermicro SYS-1028R-TDW/X10DDW-i, BIOS 3.2 12/16/2019
> > [  158.666950] RIP: 0010:xp_free+0x11/0x80
> > [  158.666962] Code: 8b 04 d0 48 83 e0 fe 48 01 f0 c3 cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 41 56 41 55 41 54 55 48 8d 6f 58 53 <48> 8b 47 58 48 39 c5 74 0d 5b 5d 41 5c 41 5d 41 5e c3 cc cc cc cc
> > [  158.666985] RSP: 0018:ffffa65089e8b760 EFLAGS: 00010202
> > [  158.666993] RAX: ffff8fcf077c0000 RBX: 0000000000000001 RCX: 0000000000000000
> > [  158.667003] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffa6510e558068
> > [  158.667012] RBP: ffffa6510e5580c0 R08: fffff8c50415a108 R09: ffff8fc7cac60000
> > [  158.667022] R10: 0000000000000219 R11: ffffffffffffffff R12: 0000000000000fff
> > [  158.667031] R13: 0000000000000000 R14: 0000000000000000 R15: ffff8fc7c139d340
> > [  158.667040] FS:  00007f8504996880(0000) GS:ffff8fcedfdc0000(0000) knlGS:0000000000000000
> > [  158.667050] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> > [  158.667058] CR2: ffffa6510e5580c0 CR3: 00000001448e2002 CR4: 00000000001706e0
> > [  158.667068] Call Trace:
> > [  158.667075]  <TASK>
> > [  158.667082]  ? show_trace_log_lvl+0x1c4/0x2df
> > [  158.667094]  ? show_trace_log_lvl+0x1c4/0x2df
> > [  158.667103]  ? ice_xsk_clean_rx_ring+0x39/0x60 [ice]
> > [  158.667157]  ? __die_body.cold+0x8/0xd
> > [  158.667166]  ? page_fault_oops+0xac/0x150
> > [  158.667176]  ? fixup_exception+0x22/0x340
> > [  158.667185]  ? exc_page_fault+0xb2/0x150
> > [  158.667195]  ? asm_exc_page_fault+0x22/0x30
> > [  158.667206]  ? xp_free+0x11/0x80
> > [  158.667215]  ice_xsk_clean_rx_ring+0x39/0x60 [ice]
> > [  158.667250]  ice_clean_rx_ring+0x157/0x180 [ice]
> > [  158.667284]  ice_down+0x172/0x2b0 [ice]
> > [  158.667311]  ? ice_xdp_setup_prog+0x3b0/0x3b0 [ice]
> > [  158.667337]  ice_xdp_setup_prog+0xe3/0x3b0 [ice]
> > [  158.667364]  ? ice_xdp_setup_prog+0x3b0/0x3b0 [ice]
> > [  158.667391]  dev_xdp_install+0xc7/0x100
> > [  158.667402]  dev_xdp_attach+0x1e0/0x560
> > [  158.667412]  do_setlink+0x7a8/0xc10
> > [  158.667422]  ? __nla_validate_parse+0x12b/0x1b0
> > [  158.667436]  __rtnl_newlink+0x540/0x650
> > [  158.667446]  rtnl_newlink+0x44/0x70
> > [  158.667454]  rtnetlink_rcv_msg+0x15c/0x3d0
> > [  158.667477]  ? rtnl_calcit.isra.0+0x140/0x140
> > [  158.667485]  netlink_rcv_skb+0x51/0x100
> > [  158.667727]  netlink_unicast+0x246/0x360
> > [  158.667953]  netlink_sendmsg+0x24e/0x4b0
> > [  158.668173]  __sock_sendmsg+0x62/0x70
> > [  158.668389]  ____sys_sendmsg+0x247/0x2d0
> > [  158.668602]  ? copy_msghdr_from_user+0x6d/0xa0
> > [  158.668815]  ___sys_sendmsg+0x88/0xd0
> > [  158.669028]  ? __sk_destruct+0x156/0x230
> > [  158.669234]  ? kmem_cache_free+0x134/0x300
> > [  158.669437]  ? rcu_nocb_try_bypass+0x4a/0x440
> > [  158.669634]  ? __sk_destruct+0x156/0x230
> > [  158.669825]  ? _raw_spin_unlock_irqrestore+0x23/0x40
> > [  158.670010]  ? mod_objcg_state+0xc9/0x2f0
> > [  158.670186]  ? refill_obj_stock+0xae/0x160
> > [  158.670359]  ? rseq_get_rseq_cs.isra.0+0x16/0x220
> > [  158.670529]  ? rcu_nocb_try_bypass+0x4a/0x440
> > [  158.670696]  ? rseq_ip_fixup+0x72/0x1e0
> > [  158.670860]  __sys_sendmsg+0x59/0xa0
> > [  158.671021]  ? syscall_trace_enter.constprop.0+0x11e/0x190
> > [  158.671185]  do_syscall_64+0x35/0x80
> > [  158.671345]  entry_SYSCALL_64_after_hwframe+0x6e/0xd8
> > [  158.671503] RIP: 0033:0x7f850510f917
> > [  158.671658] Code: 0e 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b9 0f 1f 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 89 54 24 1c 48 89 74 24 10
> > [  158.671993] RSP: 002b:00007ffcc805f238 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
> > [  158.672171] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f850510f917
> > [  158.672352] RDX: 0000000000000000 RSI: 000000000198e9e8 RDI: 0000000000000009
> > [  158.672534] RBP: 0000000001933c00 R08: 0000000001935980 R09: 0000000000460e48
> > [  158.672716] R10: 0000000000000011 R11: 0000000000000246 R12: 0000000001933c30
> > [  158.672899] R13: 0000000000515fd8 R14: 000000000198e9d0 R15: 0000000000513690
> > [  158.673086]  </TASK>
> > [  158.673269] Modules linked in: bonding(E) tls(E) nft_fib_inet(E) nft_fib_ipv4(E) nft_fib_ipv6(E) nft_fib(E) nft_reject_inet(E) nf_reject_ipv4(E) nf_reject_ipv6(E) nft_reject(E) nft_ct(E) nft_chain_nat(E) nf_nat(E) nf_conntrack(E) nf_defrag_ipv6(E) nf_defrag_ipv4(E) rfkill(E) ip_set(E) nf_tables(E) libcrc32c(E) nfnetlink(E) vfat(E) fat(E) ipmi_ssif(E) intel_rapl_msr(E) intel_rapl_common(E) sb_edac(E) x86_pkg_temp_thermal(E) intel_powerclamp(E) coretemp(E) kvm_intel(E) iTCO_wdt(E) intel_pmc_bxt(E) iTCO_vendor_support(E) kvm(E) irqbypass(E) rapl(E) intel_cstate(E) ast(E) intel_uncore(E) drm_vram_helper(E) drm_ttm_helper(E) ttm(E) pcspkr(E) mei_me(E) drm_kms_helper(E) i2c_i801(E) lpc_ich(E) mei(E) i2c_smbus(E) mxm_wmi(E) ioatdma(E) acpi_ipmi(E) ipmi_si(E) ipmi_devintf(E) ipmi_msghandler(E) acpi_pad(E) acpi_power_meter(E) joydev(E) drm(E) fuse(E) ext4(E) mbcache(E) jbd2(E) sd_mod(E) t10_pi(E) sg(E) ahci(E) crct10dif_pclmul(E) crc32_pclmul(E) libahci(E) crc32c_intel(E) ice(E)
> > [  158.673314]  polyval_clmulni(E) polyval_generic(E) igb(E) libata(E) ghash_clmulni_intel(E) i2c_algo_bit(E) dca(E) wmi(E) dm_mirror(E) dm_region_hash(E) dm_log(E) dm_mod(E)
> > [  158.675578] CR2: ffffa6510e5580c0