graphic: 0.947
instruction: 0.923
other: 0.920
semantic: 0.915
KVM: 0.908
device: 0.907
assembly: 0.906
vnc: 0.903
network: 0.886
boot: 0.866
mistranslation: 0.852
socket: 0.836

CPU of qemu-system-aarch64 always stuck

I started qemu with these arguments:
 qemu-system-aarch64 -M virt-2.9 -cpu cortex-a72 -smp cores=8,threads=1,sockets=1 -m 2G -device nec-usb-xhci -device usb-kbd -device usb-tablet -pflash /sdcard/QEMU_EFI.img -pflash /sdcard/QEMU_VARS.img -device virtio-blk-device,drive=Ubuntu -drive if=none,id=Ubuntu,file=Ubuntu.vhd -nographic -net user -net nic,model=rtl8139 -kernel linux -initrd initrd.gz
The setup program of Ubuntu devel aarch64 ran normally.But after several hours,the CPUs emulated by qemu-system-aarch64 went wrong.
Here are the messages displayed on the tty
[15842.164745] watchdog: BUG: soft lockup - CPU#0 stuck for 23s! [ksoftirqd/0:9]                                                                         [15930.163589] watchdog: BUG: soft lockup - CPU#0 stuck for 23s! [ksoftirqd/0:9]
[16110.163540] watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [ksoftirqd/0:9] 
[16290.162801] watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [ksoftirqd/0:9]
[16470.163927] watchdog: BUG: soft lockup - CPU#0 stuck for 23s! [ksoftirqd/0:9] 
[16650.163246] watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [ksoftirqd/0:9] 
[16830.163216] watchdog: BUG: soft lockup - CPU#0 stuck for 23s! [ksoftirqd/0:9] 
[17010.164504] watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [ksoftirqd/0:9]

Then I tried CentOS 7.1908 aarch64 with almost the same arguments.
After several hours,it went wrong too.
[17480 . 201 1 58] rcu : (3 ticks this GP) idle=362/0/0x3 softirq=61631 /61 631 fqs=10077
[17480 . 204889] (detected by 3 , t=24007 jiffies , g=218453 , q=5285) [1 7480 . 21 7986] Task dump for CPU 7 :
[17480.222379] swapper/7R running task	0 
0  0x0000002a [17480.229073] Call trace :
[1 7480.241518]	switch t0+0x104/0x1 f8
[17480.249839]	Ox7fffffffffffffff
[17660.232314] rcu : INFO: rcu sched detected stalls on CPUs/ tasks :
[17660.233580] rcu : (3 ticks this GP) idle=362/0/0x3 softirq=61631 /61 631 fqs=17770
[17660.235837] (detected by 3,t=42012 jiffies , g=218453 , q=7039) 
[17660 . 237955] Task dump for CPU 7 :
[17660.238900] swapper/ 7  R running task  0   0
[17660.242967] Call trace :
[17660.246192]	switch t0+0x104/0x1 f8
[17660.253215]	Ox7fffffffffffffff

Obviously qemu-system-aarch64 caused these bugs.

qemu version: 4.x(I have tested version 4.0 & 4.1.0 & 4.2.0)
host architecture: aarch64(Qualcomm Snapdragon series)
host system:Ubuntu devel 20.04& Debian 10(I have tested on many devices)

The QEMU project is currently considering to move its bug tracking to
another system. For this we need to know which bugs are still valid
and which could be closed already. Thus we are setting older bugs to
"Incomplete" now.

If you still think this bug report here is valid, then please switch
the state back to "New" within the next 60 days, otherwise this report
will be marked as "Expired". Or please mark it as "Fix Released" if
the problem has been solved with a newer version of QEMU already.

Thank you and sorry for the inconvenience.


[Expired for QEMU because there has been no activity for 60 days.]