Re: Shutting down a VM with Kernel 4.14 will sometime hang and a reboot is the only way to recover.

[David Hill <dhill@redhat.com>]

Anyone had time to take a little look at the kernel trace?


On 2017-11-15 04:08 PM, David Hill wrote:
> Hi guys,
>
>     The same behavior is seen with 4.15-rc0 :
>
> $ sudo virsh list
>  Id    Name                           State
> ----------------------------------------------------
>  2     undercloud-0-pike              in shutdown
>
> $ uname -a
> Linux zappa.orion 4.15.0-0.rc0.git1.1.fc28.x86_64 #1 SMP Mon Nov 13 
> 19:54:17 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux
>
>
> $ ps aufxg | grep qemu
>
> qemu      8595 81.6 12.8 22831200 16961240 ?   D    11:44 214:26 
> /usr/bin/qemu-system-x86_64 -machine accel=kvm -name 
> guest=undercloud-0-pike,debug-threads=on -S -object 
> secret,id=masterKey0,format=raw,file=/var/lib/libvirt/qemu/domain-2-undercloud-0-pike/master-key.aes 
> -machine 
> pc-i440fx-2.10,accel=kvm,usb=off,vmport=off,dump-guest-core=off -cpu 
> Westmere -m 16384 -realtime mlock=off -smp 
> 4,sockets=4,cores=1,threads=1 -uuid 
> 0de0918d-f67e-426a-91c1-5e38e86c96b3 -no-user-config -nodefaults 
> -chardev 
> socket,id=charmonitor,path=/var/lib/libvirt/qemu/domain-2-undercloud-0-pike/monitor.sock,server,nowait 
> -mon chardev=charmonitor,id=monitor,mode=control -rtc 
> base=utc,driftfix=slew -global kvm-pit.lost_tick_policy=delay -no-hpet 
> -no-shutdown -global PIIX4_PM.disable_s3=1 -global 
> PIIX4_PM.disable_s4=1 -boot menu=on,strict=on -device 
> ich9-usb-ehci1,id=usb,bus=pci.0,addr=0x6.0x7 -device 
> ich9-usb-uhci1,masterbus=usb.0,firstport=0,bus=pci.0,multifunction=on,addr=0x6 
> -device 
> ich9-usb-uhci2,masterbus=usb.0,firstport=2,bus=pci.0,addr=0x6.0x1 
> -device 
> ich9-usb-uhci3,masterbus=usb.0,firstport=4,bus=pci.0,addr=0x6.0x2 
> -device virtio-serial-pci,id=virtio-serial0,bus=pci.0,addr=0x5 -drive 
> file=/var/lib/jenkins/VMs/undercloud-0-pike.qcow2,format=qcow2,if=none,id=drive-virtio-disk0 
> -device 
> virtio-blk-pci,scsi=off,bus=pci.0,addr=0x9,drive=drive-virtio-disk0,id=virtio-disk0,bootindex=2 
> -drive if=none,id=drive-ide0-0-0,readonly=on -device 
> ide-cd,bus=ide.0,unit=0,drive=drive-ide0-0-0,id=ide0-0-0,bootindex=3 
> -netdev tap,fd=28,id=hostnet0,vhost=on,vhostfd=30 -device 
> virtio-net-pci,netdev=hostnet0,id=net0,mac=52:54:00:79:8e:41,bus=pci.0,addr=0x3,bootindex=1 
> -netdev tap,fd=31,id=hostnet1,vhost=on,vhostfd=32 -device 
> virtio-net-pci,netdev=hostnet1,id=net1,mac=52:54:00:b8:8b:a5,bus=pci.0,addr=0x8 
> -chardev pty,id=charserial0 -device 
> isa-serial,chardev=charserial0,id=serial0 -chardev 
> spicevmc,id=charchannel0,name=vdagent -device 
> virtserialport,bus=virtio-serial0.0,nr=1,chardev=charchannel0,id=channel0,name=com.redhat.spice.0 
> -spice 
> port=5900,addr=0.0.0.0,disable-ticketing,image-compression=off,seamless-migration=on 
> -device 
> qxl-vga,id=video0,ram_size=67108864,vram_size=67108864,vram64_size_mb=0,vgamem_mb=16,max_outputs=1,bus=pci.0,addr=0x2 
> -device intel-hda,id=sound0,bus=pci.0,addr=0x4 -device 
> hda-duplex,id=sound0-codec0,bus=sound0.0,cad=0 -chardev 
> spicevmc,id=charredir0,name=usbredir -device 
> usb-redir,chardev=charredir0,id=redir0,bus=usb.0,port=1 -chardev 
> spicevmc,id=charredir1,name=usbredir -device 
> usb-redir,chardev=charredir1,id=redir1,bus=usb.0,port=2 -device 
> virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x7 -msg timestamp=on
>
> Thank you very much,
>
> David Hill
>
>
> On 2017-11-14 10:44 AM, Dave Hill wrote:
>> I'm not able to bisect further as the system wont boot properly when 
>> I reach that commit.
>>
>> On Mon, Nov 13, 2017 at 10:54 AM, David Hill <dhill@redhat.com 
>> <mailto:dhill@redhat.com>> wrote:
>>
>>
>>     Hi guys,
>>
>>        Starting with kernel 4.14-rc1, my CI failed to completely
>>     shutdown one of the
>>     VMs and it stuck in "in shutdown" while sending this kernel message:
>>
>>     [ 7496.552971] INFO: task qemu-system-x86:5978 blocked for more
>>     than 120 seconds.
>>     [ 7496.552987]       Tainted: G          I
>>     4.14.0-0.rc1.git3.1.fc28.x86_64 #1
>>     [ 7496.552996] "echo 0 /proc/sys/kernel/hung_task_timeout_secs"
>>     disables this message.
>>     [ 7496.553006] qemu-system-x86 D12240  5978      1 0x00000004
>>     [ 7496.553024] Call Trace:
>>     [ 7496.553044]  __schedule+0x2dc/0xbb0
>>     [ 7496.553055]  ? trace_hardirqs_on+0xd/0x10
>>     [ 7496.553074]  schedule+0x3d/0x90
>>     [ 7496.553087]  vhost_net_ubuf_put_and_wait+0x73/0xa0 [vhost_net]
>>     [ 7496.553100]  ? finish_wait+0x90/0x90
>>     [ 7496.553115]  vhost_net_ioctl+0x542/0x910 [vhost_net]
>>     [ 7496.553144]  do_vfs_ioctl+0xa6/0x6c0
>>     [ 7496.553166]  SyS_ioctl+0x79/0x90
>>     [ 7496.553182]  entry_SYSCALL_64_fastpath+0x1f/0xbe
>>     [ 7496.553190] RIP: 0033:0x7fa1ea0e1817
>>     [ 7496.553196] RSP: 002b:00007ffe3d854bc8 EFLAGS: 00000246
>>     ORIG_RAX: 0000000000000010
>>     [ 7496.553209] RAX: ffffffffffffffda RBX: 000000000000001d RCX:
>>     00007fa1ea0e1817
>>     [ 7496.553215] RDX: 00007ffe3d854bd0 RSI: 000000004008af30 RDI:
>>     0000000000000021
>>     [ 7496.553222] RBP: 000055e33352b610 R08: 000055e33024a6f0 R09:
>>     000055e330245d92
>>     [ 7496.553228] R10: 000055e33344e7f0 R11: 0000000000000246 R12:
>>     000055e33351a000
>>     [ 7496.553235] R13: 0000000000000001 R14: 0000000400000000 R15:
>>     0000000000000000
>>     [ 7496.553284]
>>                    Showing all locks held in the system:
>>     [ 7496.553313] 1 lock held by khungtaskd/161:
>>     [ 7496.553319]  #0:  (tasklist_lock){.+.+}, at:
>>     [<ffffffff8111740d>] debug_show_all_locks+0x3d/0x1a0
>>     [ 7496.553373] 1 lock held by in:imklog/1194:
>>     [ 7496.553379]  #0:  (&f->f_pos_lock){+.+.}, at:
>>     [<ffffffff8130ecfc>] __fdget_pos+0x4c/0x60
>>     [ 7496.553541] 1 lock held by qemu-system-x86/5978:
>>     [ 7496.553547]  #0:  (&dev->mutex#3){+.+.}, at:
>>     [<ffffffffc077e498>] vhost_net_ioctl+0x358/0x910 [vhost_net]
>>
>>
>>
>>     I'm currently bisecting to figure out which commit breaks this but
>>     for some reasons, when hitting this commit:
>>
>>     # bad: [46d4b68f891bee5d83a32508bfbd9778be6b1b63] Merge tag
>>     'wireless-drivers-next-for-davem-2017-08-07' of
>> git://git.kernel.org/pub/scm/linux/kernel/git/kvalo/wireless-drivers-next
>> <http://git.kernel.org/pub/scm/linux/kernel/git/kvalo/wireless-drivers-next>
>>     git bisect bad 46d4b68f891bee5d83a32508bfbd9778be6b1b63
>>
>>     the host will not allow SSHd to establish a new session and when
>>     starting a KVM guest, the host will hard lock.   I'm still
>>     bisecting but I marked that commit as bad even though perhaps it
>>     would be good.
>>     Hopefully, this commit was a bad one and my bisection will
>>     pinpoint which
>>     commit broke the kernel.    If you have an idea of which commit
>>     might break
>>     the system, please let me know which one I should test first.
>>
>>     Thank you very much,
>>     David Hill
>>
>>     [1] https://bugzilla.kernel.org/show_bug.cgi?id=197861
>>     <https://bugzilla.kernel.org/show_bug.cgi?id=197861>
>>
>>
>>
>