Hi all, I've seen several posts in the list that seem to have only experienced this warning on 4.13: [94415.028749] WARNING: CPU: 30 PID: 18142 at arch/x86/kvm/mmu.c:717 mmu_spte_clear_track_bits+0xf0/0x100 [kvm] [94415.028753] Modules linked in: rpcsec_gss_krb5 auth_rpcgss oid_registry nfsv4 dns_resolver nfs lockd grace sunrpc fscache vhost_net vhost tap xt_conntrack xt_CHECKSUM iptable_mangle ipt_REJECT nf_reject_ipv4 xt_tcpudp tun ebtable_filter ebtables ip6table_filter ip6_tables iptable_filter msr ipt_MASQUERADE nf_nat_masquerade_ipv4 iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack zfs(PO) zunicode(PO) uvcvideo intel_rapl zavl(PO) nls_iso8859_1 nls_cp437 icp(PO) videobuf2_vmalloc videobuf2_memops input_leds led_class videobuf2_v4l2 mousedev joydev videobuf2_core x86_pkg_temp_thermal intel_powerclamp videodev hid_logitech_hidpp coretemp snd_usb_audio snd_usbmidi_lib crct10dif_pclmul media uas zcommon(PO) znvpair(PO) crc32_pclmul hid_logitech_dj drm_kms_helper hid_generic ghash_clmulni_intel [94415.028791] pcbc aesni_intel drm aes_x86_64 crypto_simd snd_hda_codec_realtek iTCO_wdt iTCO_vendor_support snd_hda_codec_generic glue_helper mac_hid mxm_wmi evdev cryptd snd_hda_intel syscopyarea snd_virtuoso snd_hda_codec sysfillrect snd_oxygen_lib sysimgblt intel_cstate snd_mpu401_uart fb_sys_fops snd_hda_core intel_rapl_perf snd_rawmidi snd_seq_device igb snd_hwdep snd_pcm snd_timer ptp snd pps_core soundcore i2c_algo_bit pcspkr ioatdma i2c_i801 shpchp dca lpc_ich bridge tpm_tis tpm_tis_core tpm stp llc acpi_power_meter wmi button sch_fq_codel kvm_intel kvm sg ip_tables x_tables usbhid hid usb_storage sr_mod cdrom spl(O) vfio_pci irqbypass vfio_virqfd vfio_iommu_type1 vfio vfat fat ext4 crc16 mbcache sd_mod jbd2 fscrypto dm_thin_pool dm_cache dm_persistent_data dm_bio_prison dm_bufio dm_raid [94415.028832] raid456 libcrc32c crc32c_generic async_raid6_recov async_memcpy async_pq async_xor xor async_tx crc32c_intel ahci xhci_pci libahci xhci_hcd libata usbcore scsi_mod usb_common raid6_pq dm_mod dax raid1 md_mod [94415.028844] CPU: 30 PID: 18142 Comm: qemu-system-x86 Tainted: P B W O 4.13.0-rc5-g58d4e450a490 #1 [94415.028848] Hardware name: Supermicro SYS-7038A-I/X10DAI, BIOS 2.0a 11/09/2016 [94415.028852] task: ffff8804946a1d80 task.stack: ffffc9000eedc000 [94415.028858] RIP: 0010:mmu_spte_clear_track_bits+0xf0/0x100 [kvm] [94415.028860] RSP: 0018:ffffc9000eedfb18 EFLAGS: 00010246 [94415.028863] RAX: 0000000000000000 RBX: 00000002428a6f77 RCX: dead0000000000ff [94415.028866] RDX: 0000000000000000 RSI: ffff88015d34c670 RDI: ffffea00090a2980 [94415.028868] RBP: ffffc9000eedfb30 R08: 0000000000000101 R09: ffff8802eda50218 [94415.028871] R10: ffff8802eda50008 R11: ffff8802eda50000 R12: 00000000002428a6 [94415.028874] R13: ffff8803f6280000 R14: ffff88015d2dac78 R15: 0000000000000000 [94415.028892] FS: 00007f43a6d7a380(0000) GS:ffff88105d580000(0000) knlGS:0000000000000000 [94415.028896] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [94415.028899] CR2: 0000000000000000 CR3: 0000000495c69000 CR4: 00000000003426e0 [94415.028902] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [94415.028904] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [94415.028907] Call Trace: [94415.028913] drop_spte+0x1a/0xb0 [kvm] [94415.028920] nmmu_page_zap_pte+0x9d/0xe0 [kvm] [94415.028927] kvm_mmu_prepare_zap_page+0x65/0x320 [kvm] [94415.028934] kvm_mmu_invalidate_zap_all_pages+0x10d/0x160 [kvm] [94415.028941] kvm_mmu_invalidate_zap_pages_in_memslot+0xe/0x10 [kvm] [94415.028949] kvm_page_track_flush_slot+0x59/0x80 [kvm] [94415.028957] kvm_arch_flush_shadow_memslot+0xe/0x10 [kvm] [94415.028982] __kvm_set_memory_region+0x807/0x8d0 [kvm] [94415.029027] kvm_set_memory_region+0x2b/0x40 [kvm] [94415.029039] kvm_vm_ioctl+0x496/0x860 [kvm] [94415.029047] do_vfs_ioctl+0xa5/0x600 [94415.029053] ? handle_mm_fault+0xde/0x1e0 [94415.029058] ? __fget+0x6e/0x90 [94415.029061] SyS_ioctl+0x79/0x90 [94415.029066] entry_SYSCALL_64_fastpath+0x1a/0xa5 [94415.029069] RIP: 0033:0x7f439fb678b7 [94415.029072] RSP: 002b:00007fff950bc298 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [94415.029077] RAX: ffffffffffffffda RBX: 0000000000000500 RCX: 00007f439fb678b7 [94415.029080] RDX: 00007fff950bc330 RSI: 000000004020ae46 RDI: 000000000000000e [94415.029084] RBP: 00007f439459c190 R08: 0000000000000078 R09: 000000000000000c [94415.029087] R10: 00007f43a0dfa188 R11: 0000000000000246 R12: 00007fff950bc150 [94415.029090] R13: 0000000000000014 R14: 0000000000000000 R15: 0000000000000015 [94415.029094] Code: 5f 04 00 48 85 c0 75 1c 4c 89 e7 e8 9b 2d fe ff 48 8b 05 d4 5f 04 00 48 85 c0 74 be 48 85 c3 0f 95 c3 eb bc 48 85 c3 74 e7 eb dd <0f> ff eb 9b 4c 89 e7 e8 74 2d fe ff eb a1 66 90 0f 1f 44 00 00 [94415.029126] ---[ end trace b22f89e13b4d9fc8 ]--- I've received this issue on both 4.12 and 4.13. It appears more frequently on 4.13, but also has a smaller overall negative system impact. I've put additional information on the kernel bugzilla at https://bugzilla.kernel.org/show_bug.cgi?id=196717. I suspect it involves the access_dirty flag that was first enabled in 4.12. Thanks, Jeff
