domU will hang after reboot in dom0-less arch on arm

[高钧浩 <gaojunhao0504@xxxxxxxxx>]

Hi，
I use u-boot, xen, qemu to boot domU, then execute "reboot" command in
domU, domU
will hang. Could someone know this issue and this feature is supported
or not. Thanks.

#####################################hang
info############################################
Welcome to SNPS Mini AArch64 by Buildroot
mini-aarch64 login: root
#
#
# reboot
# Stopping network: ifdown: interface eth0 not configured
OK
Saving random seed: OK
Stopping klogd: OK
Stopping syslogd: OK
umount: devtmpfs busy - remounted read-only
umount: can't unmount /: Invalid argument
The system is going down NOW!
Sent SIGTERM to all processes
Sent SIGKILL to all processes
Requesting system reboot
[   47.461948] Flash device refused suspend due to active operation (state 20)
[   47.466276] Flash device refused suspend due to active operation (state 20)
[   47.472966] reboot: Restarting system
(XEN) Hardware Dom0 shutdown: rebooting machine


U-Boot 2024.01 (Jun 04 2024 - 19:56:53 +0800)

DRAM:  4 GiB
Core:  51 devices, 14 uclasses, devicetree: board
Flash: 64 MiB
Loading Environment from Flash... *** Warning - bad CRC, using default
environment

In:    serial,usbkbd
Out:   serial,vidconsole
Err:   serial,vidconsole
No working controllers found
Net:   eth0: virtio-net#32
starting USB...
No working controllers found
Hit any key to stop autoboot:  0
Scanning for bootflows in all bootdevs
Seq  Method       State   Uclass    Part  Name                      Filename
---  -----------  ------  --------  ----  ------------------------
----------------
Scanning global bootmeth 'efi_mgr':
No EFI system partition
No EFI system partition
Failed to persist EFI variables
Missing TPMv2 device for EFI_TCG_PROTOCOL
Missing RNG device for EFI_RNG_PROTOCOL
Scanning bootdev 'fw-cfg@9020000.bootdev':
fatal: no kernel available
No working controllers found
scanning bus for devices...
BOOTP broadcast 1
##########################################################################################

software version:
u-boot: v2024.01
xen: 4.18.0
qemu: 8.1.3

qemu command:
qemu-system-aarch64 \
-machine virt,gic_version=3 \
-machine virtualization=true \
-cpu cortex-a57 \
-machine type=virt \
-m 4096 \
-smp 4 \
-bios u-boot.bin \
-device loader,file=xen,force-raw=on,addr=0x49000000 \
-device loader,file=virt-gicv3.dtb,addr=0x44000000 \
-device loader,file=Image,addr=0x54000000 \
-device loader,file=rootfs.img.gz,addr=0x59000000 \
-device loader,file=Image,addr=0x64000000 \
-device loader,file=rootfs.img.gz,addr=0x69000000 \
-nographic \
-chardev 
socket,id=qemu-monitor,host=localhost,port=7777,server=on,wait=off,telnet=on
\
-mon qemu-monitor,mode=readline

Thanks,
Junhao Gao