Re: WARNING trace at kvm_nx_huge_page_recovery_worker on 6.3.4

From: Fabio Coatti <fabio.coatti@gmail.com>
To: Sean Christopherson <seanjc@google.com>
Cc: stable@vger.kernel.org, regressions@lists.linux.dev, kvm@vger.kernel.org
Subject: Re: WARNING trace at kvm_nx_huge_page_recovery_worker on 6.3.4
Date: Sun, 28 May 2023 12:54:37 +0200	[thread overview]
Message-ID: <CADpTngW6KU+VvRD2gwU8XbSedMEy8WTBiEWG=LnfaEZfCDXCLA@mail.gmail.com> (raw)
In-Reply-To: <ZHDl6rXQ0UTWdk2O@google.com>

Il giorno ven 26 mag 2023 alle ore 19:01 Sean Christopherson
<seanjc@google.com> ha scritto:

>
> Do you have the actual line number for the WARN?  There are a handful of sanity
> checks in kvm_recover_nx_huge_pages(), it would be helpful to pinpoint which one
> is firing.  My builds generate quite different code, and the code stream doesn't
> appear to be useful for reverse engineering the location.

Just got the following: arch/x86/kvm/mmu/mmu.c:7015 so seemingly around here:

if (atomic_read(&kvm->nr_memslots_dirty_logging)) {
slot = gfn_to_memslot(kvm, sp->gfn);
WARN_ON_ONCE(!slot);
}

[Sun May 28 12:48:12 2023] ------------[ cut here ]------------
[Sun May 28 12:48:12 2023] WARNING: CPU: 1 PID: 3911 at
arch/x86/kvm/mmu/mmu.c:7015
kvm_nx_huge_page_recovery_worker+0x38c/0x3d0 [kvm]
[Sun May 28 12:48:12 2023] Modules linked in: vhost_net vhost
vhost_iotlb tap tun rfcomm snd_hrtimer snd_seq xt_CHECKSUM
xt_MASQUERADE xt_conntrack ipt_REJECT nf_reject_ipv4 ip6table_mangle
ip6table_nat ip6table_filter ip6_tables iptable_mangle iptable_nat
nf_nat iptable_filter ip_tables bpfilter bridge stp llc algif_skcipher
bnep rmi_smbus rmi_core squashfs sch_fq_codel vboxnetadp(OE)
nvidia_drm(POE) vboxnetflt(OE) rtsx_pci_sdmmc intel_rapl_msr
nvidia_modeset(POE) mmc_core mei_pxp mei_hdcp vboxdrv(OE) snd_ctl_led
intel_rapl_common snd_hda_codec_realtek intel_pmc_core_pltdrv
snd_hda_codec_generic intel_pmc_core intel_tcc_cooling
x86_pkg_temp_thermal intel_powerclamp btusb snd_hda_intel btrtl btbcm
snd_intel_dspcfg btmtk snd_usb_audio kvm_intel btintel snd_usbmidi_lib
snd_hda_codec snd_hwdep kvm snd_rawmidi iwlmvm snd_hda_core
snd_seq_device bluetooth snd_pcm thinkpad_acpi irqbypass
crct10dif_pclmul crc32_pclmul snd_timer mei_me ledtrig_audio
ecdh_generic psmouse joydev think_lmi uvcvideo polyval_clmulni snd
polyval_generic wmi_bmof
[Sun May 28 12:48:12 2023]  firmware_attributes_class iwlwifi rtsx_pci
uvc ecc mousedev soundcore mei intel_pch_thermal platform_profile
evdev input_leds nvidia(POE) coretemp hwmon akvcam(OE)
videobuf2_vmalloc videobuf2_memops videobuf2_v4l2 videodev
videobuf2_common mc loop nfsd auth_rpcgss nfs_acl efivarfs dmi_sysfs
dm_zero dm_thin_pool dm_persistent_data dm_bio_prison dm_service_time
dm_round_robin dm_queue_length dm_multipath dm_delay virtio_pci
virtio_pci_legacy_dev virtio_pci_modern_dev virtio_blk virtio_console
virtio_balloon vxlan ip6_udp_tunnel udp_tunnel macvlan virtio_net
net_failover failover virtio_ring virtio fuse overlay nfs lockd grace
sunrpc linear raid10 raid1 raid0 dm_raid raid456 async_raid6_recov
async_memcpy async_pq async_xor async_tx md_mod dm_snapshot dm_bufio
dm_crypt trusted asn1_encoder tpm rng_core dm_mirror dm_region_hash
dm_log firewire_core crc_itu_t hid_apple usb_storage ehci_pci ehci_hcd
sr_mod cdrom ahci libahci libata
[Sun May 28 12:48:12 2023] CPU: 1 PID: 3911 Comm: kvm-nx-lpage-re
Tainted: P     U     OE      6.3.4-cova #2
[Sun May 28 12:48:12 2023] Hardware name: LENOVO
20EQS58500/20EQS58500, BIOS N1EET98W (1.71 ) 12/06/2022
[Sun May 28 12:48:12 2023] RIP:
0010:kvm_nx_huge_page_recovery_worker+0x38c/0x3d0 [kvm]
[Sun May 28 12:48:12 2023] Code: 48 8b 44 24 30 4c 39 e0 0f 85 1b fe
ff ff 48 89 df e8 2e ab fb ff e9 23 fe ff ff 49 bc ff ff ff ff ff ff
ff 7f e9 fb fc ff ff <0f> 0b e9 1b ff ff ff 48 8b 44 24 40 65 48 2b 04
25 28 00 00 00 75
[Sun May 28 12:48:12 2023] RSP: 0018:ffff99b284f0be68 EFLAGS: 00010246
[Sun May 28 12:48:12 2023] RAX: 0000000000000000 RBX: ffff99b284edd000
RCX: 0000000000000000
[Sun May 28 12:48:12 2023] RDX: 0000000000000000 RSI: 0000000000000000
RDI: 0000000000000000
[Sun May 28 12:48:12 2023] RBP: ffff9271397024e0 R08: 0000000000000000
R09: ffff927139702450
[Sun May 28 12:48:12 2023] R10: 0000000000000000 R11: 0000000000000001
R12: ffff99b284f0be98
[Sun May 28 12:48:12 2023] R13: 0000000000000000 R14: ffff9270991fcd80
R15: 0000000000000003
[Sun May 28 12:48:12 2023] FS:  0000000000000000(0000)
GS:ffff927f9f640000(0000) knlGS:0000000000000000
[Sun May 28 12:48:12 2023] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[Sun May 28 12:48:12 2023] CR2: 00007f0aacad3ae0 CR3: 000000088fc2c005
CR4: 00000000003726e0
[Sun May 28 12:48:12 2023] Call Trace:
[Sun May 28 12:48:12 2023]  <TASK>
[Sun May 28 12:48:12 2023]  ?
__pfx_kvm_nx_huge_page_recovery_worker+0x10/0x10 [kvm]
[Sun May 28 12:48:12 2023]  kvm_vm_worker_thread+0x106/0x1c0 [kvm]
[Sun May 28 12:48:12 2023]  ? __pfx_kvm_vm_worker_thread+0x10/0x10 [kvm]
[Sun May 28 12:48:12 2023]  kthread+0xd9/0x100
[Sun May 28 12:48:12 2023]  ? __pfx_kthread+0x10/0x10
[Sun May 28 12:48:12 2023]  ret_from_fork+0x2c/0x50
[Sun May 28 12:48:12 2023]  </TASK>
[Sun May 28 12:48:12 2023] ---[ end trace 0000000000000000 ]---

-- 
Fabio