Hello everyone,

I am relatively new to the community, thanks in advance for your time and help.

I have an openstack cluster ready, working with several compute nodes based on x86 architecture. My current installation is based on Ussuri.

I have recently acquired a couple of nvidia Jetson devices (https://www.nvidia.com/en-us/autonomous-machines/embedded-systems/jetson-agx-xavier/) which I want to connect to the cluster.

The arm cpu model name is ARMv8 Processor rev 0 (v8l).

CPU flags on the arm architecture are different and hence egrep -c '(vmx|svm)' /proc/cpuinfo is empty to the best of my knowledge.

However, i re-build the custom linux kernel (i.e, Tegra) of the Jetson device, enabling the KVM module.

So once i used:

sudo kvm-ok

INFO: /dev/kvm exists
KVM acceleration can be used

dmesg | grep -i kvm
[ 1.372478] kvm [1]: 16-bit VMID
[ 1.372489] kvm [1]: IDMAP page: 80fa1000
[ 1.372498] kvm [1]: HYP VA range: 4000000000:7fffffffff
[ 1.374185] kvm [1]: Hyp mode initialized successfully
[ 1.374299] kvm [1]: vgic-v2@3884000
[ 1.374763] kvm [1]: vgic interrupt IRQ1
[ 1.374790] kvm [1]: virtual timer IRQ4

dmesg | grep -i 'CPU features'

[ 0.687366] CPU features: detected feature: Privileged Access Never

[ 0.687372] CPU features: detected feature: LSE atomic instructions

[ 0.687378] CPU features: detected feature: User Access Override

[ 0.687385] CPU features: detected feature: 32-bit EL0 Support

Does this suffice to say that I can use KVM with libvirt for the nova openstack?

The version of libvirt is 6.0.0.

From the nova logs i see the following with virt_type = qemu

WARNING nova.virt.libvirt.driver [-] The libvirt driver is not tested on qemu/aarch64 by the OpenStack project and thus its quality can not be ensured. For more information, see: https://docs.openstack.org/nova/latest/user/support-matrix.html

And as it detects the aarch64 device:

CPU mode "host-passthrough" was chosen

If i try to launch an instance i get the following error with qemu

libvirt.libvirtError: unsupported configuration: CPU mode 'host-passthrough' for aarch64 qemu domain on aarch64 host is not supported by hypervisor

where as i i use virt_type= kvm the error after trying to launch an instance is

libvirt.libvirtError: unsupported configuration: Emulator '/usr/bin/qemu-system-aarch64' does not support virt type 'kvm'

Any advice on how to proceed?

all the best

Pavlos.