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

[Paolo Bonzini <pbonzini@redhat.com>]

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]