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

[David Hill <dhill@xxxxxxxxxx>]

The VMs all have 2 vNICs ... and this is the hypervisor:

[root@zappa ~]# brctl show
bridge name    bridge id        STP enabled    interfaces
virbr0        8000.525400914858    yes        virbr0-nic
                            vnet0
                            vnet1


1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN 
group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever
2: eno1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP 
group default qlen 1000
    link/ether 84:2b:2b:13:f2:91 brd ff:ff:ff:ff:ff:ff
    inet redacted/24 brd 173.178.138.255 scope global dynamic eno1
       valid_lft 48749sec preferred_lft 48749sec
    inet6 fe80::862b:2bff:fe13:f291/64 scope link
       valid_lft forever preferred_lft forever
3: eno2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP 
group default qlen 1000
    link/ether 84:2b:2b:13:f2:92 brd ff:ff:ff:ff:ff:ff
    inet 192.168.1.3/24 brd 192.168.1.255 scope global eno2
       valid_lft forever preferred_lft forever
    inet6 fe80::862b:2bff:fe13:f292/64 scope link
       valid_lft forever preferred_lft forever
4: virbr0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue 
state UP group default qlen 1000
    link/ether 52:54:00:91:48:58 brd ff:ff:ff:ff:ff:ff
    inet 192.168.122.1/24 brd 192.168.122.255 scope global virbr0

       valid_lft forever preferred_lft forever
    inet 192.168.122.10/32 scope global virbr0
       valid_lft forever preferred_lft forever
    inet 192.168.122.11/32 scope global virbr0
       valid_lft forever preferred_lft forever
    inet 192.168.122.12/32 scope global virbr0
       valid_lft forever preferred_lft forever
    inet 192.168.122.15/32 scope global virbr0
       valid_lft forever preferred_lft forever
    inet 192.168.122.16/32 scope global virbr0
       valid_lft forever preferred_lft forever
    inet 192.168.122.17/32 scope global virbr0
       valid_lft forever preferred_lft forever
    inet 192.168.122.18/32 scope global virbr0
       valid_lft forever preferred_lft forever
    inet 192.168.122.31/32 scope global virbr0
       valid_lft forever preferred_lft forever
    inet 192.168.122.32/32 scope global virbr0
       valid_lft forever preferred_lft forever
    inet 192.168.122.33/32 scope global virbr0
       valid_lft forever preferred_lft forever
    inet 192.168.122.34/32 scope global virbr0
       valid_lft forever preferred_lft forever
    inet 192.168.122.35/32 scope global virbr0
       valid_lft forever preferred_lft forever
    inet 192.168.122.36/32 scope global virbr0
       valid_lft forever preferred_lft forever
    inet 192.168.122.37/32 scope global virbr0
       valid_lft forever preferred_lft forever
    inet 192.168.122.45/32 scope global virbr0
       valid_lft forever preferred_lft forever
    inet 192.168.122.46/32 scope global virbr0
       valid_lft forever preferred_lft forever
    inet 192.168.122.47/32 scope global virbr0
       valid_lft forever preferred_lft forever
    inet 192.168.122.48/32 scope global virbr0
       valid_lft forever preferred_lft forever
    inet 192.168.122.49/32 scope global virbr0
       valid_lft forever preferred_lft forever
    inet 192.168.122.50/32 scope global virbr0
       valid_lft forever preferred_lft forever
    inet 192.168.122.51/32 scope global virbr0
       valid_lft forever preferred_lft forever
5: virbr0-nic: <BROADCAST,MULTICAST> mtu 1500 qdisc fq_codel master 
virbr0 state DOWN group default qlen 1000
    link/ether 52:54:00:91:48:58 brd ff:ff:ff:ff:ff:ff
125: tun0: <POINTOPOINT,MULTICAST,NOARP,UP,LOWER_UP> mtu 1360 qdisc 
fq_codel state UNKNOWN group default qlen 100
    link/none
    inet 10.10.122.28/21 brd 10.10.127.255 scope global tun0
       valid_lft forever preferred_lft forever
    inet6 fe80::1f9b:bfd4:e9c9:2059/64 scope link stable-privacy
       valid_lft forever preferred_lft forever
402: vnet0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel 
master virbr0 state UNKNOWN group default qlen 1000
    link/ether fe:54:00:09:27:39 brd ff:ff:ff:ff:ff:ff
    inet6 fe80::fc54:ff:fe09:2739/64 scope link
       valid_lft forever preferred_lft forever
403: vnet1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel 
master virbr0 state UNKNOWN group default qlen 1000
    link/ether fe:54:00:ea:6b:18 brd ff:ff:ff:ff:ff:ff
    inet6 fe80::fc54:ff:feea:6b18/64 scope link
       valid_lft forever preferred_lft forever


On 2017-11-23 10:11 PM, Jason Wang wrote:
> On 2017年11月24日 07:48, Paolo Bonzini wrote:
> > Jason, any ideas?
> >
> > Thanks,
> >
> > Paolo
> >
> > On 22/11/2017 19:22, David Hill wrote:
> > > ore 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]
>
> Hi:
>
> The backtrace shows zero copied skb was not sent for a long while for 
> some reason. This could be either a bug in vhost_net or somewhere in 
> the host driver, qdiscs or others.
>
> What's your network setups in host (e.g the qdiscs or network driver)? 
> Can you still hit the issue if you switch to use another type of 
> ethernet driver/cards? Can this still be reproducible in net.git 
> (https://git.kernel.org/pub/scm/linux/kernel/git/davem/net.git/).
>
> Will try to reproduce this locally.
>
> Thanks