Qemu-system-aarch64: Could not set register demuxed reg

Incus
1

Hello there,

I havent seen such an error before version 7.0. My hosts information as follows and when I launch a vm, I get the mentioned error message.
incus start testvm

Error:

Failed to run: forklimits limit=memlock:unlimited:unlimited fd=3 fd=4 – /opt/incus/bin/qemu-system-aarch64 -S -name testvm -uuid 02f385ee-a666-4a96-b576-30a56af9a8b7 -daemonize -cpu host -nographic -serial chardev:console -nodefaults -no-user-config -sandbox on,obsolete=deny,elevateprivileges=allow,spawn=allow,resourcecontrol=deny -readconfig /run/incus/testvm/qemu.conf -pidfile /run/incus/testvm/qemu.pid -D /var/log/incus/testvm/qemu.log -spice unix=on,disable-ticketing=on,addr=/run/incus/testvm/qemu.spice -smbios type=2,manufacturer=LinuxContainers,product=Incus -run-with user=incus: : exit status 1
Try `incus info --show-log testvm` for more info

OS: Debian/13 Kernel: 6.1.115 - Armbian Arch: aarch64

qemu-system - 1:10.0.8+ds-0+deb13u1+b2

Anyone have any idea what could be the problem?

Regards.

2

Solved, thanks @incusteamincusteam.

3

Hello, sorry to reopen this thread, again I have this problem.
Here some system information.

indiana@tnode1:~$ incus launch images:debian/13/cloud test --vm
Launching test
Error: Failed instance creation: Failed to run: forklimits limit=memlock:unlimited:unlimited fd=3 fd=4 – /opt/incus/bin/qemu-system-aarch64 -S -name test -uuid cd3249eb-7482-4e7a-a728-db73d3837923 -daemonize -cpu host -nographic -serial chardev:console -nodefaults -no-user-config -sandbox on,obsolete=deny,elevateprivileges=allow,spawn=allow,resourcecontrol=deny -readconfig /run/incus/test/qemu.conf -pidfile /run/incus/test/qemu.pid -D /var/log/incus/test/qemu.log -spice unix=on,disable-ticketing=on,addr=/run/incus/test/qemu.spice -smbios type=2,manufacturer=LinuxContainers,product=Incus -run-with user=incus: : exit status 1

indiana@tnode1

:

~

$ incus info --show-log test
Name: test
Description: 
Status: STOPPED
Type: virtual-machine
Architecture: aarch64
Location: tnode3
Created: 2026/06/07 10:31 +03
Last Used: 1970/01/01 02:00 EET

Log (qemu.log):

qemu-system-aarch64: Could not set register demuxed reg 6020000000110000 to 701fe01a (is 700fe01a)
qemu-system-aarch64: Could not set register demuxed reg 6020000000110001 to 201fe01a (is 200fe01a)
qemu-system-aarch64: Could not set register demuxed reg 6020000000110002 to 707fe03a (is 703fe01a)
qemu-system-aarch64: Failed to put registers after init: Invalid argument
4

Hello, the AI suggest that, changing the raw.qemu parameter as -cpu max can solve the case. But in the raw qemu parameter in incus there also -cpu host added. How can I omit the -cpu host or any suggestion for that?

Regards.