Hello.

I'm running Debian bookworm on my ARM Chromebook,model "xe303c12" and 
I've recompiled the kernel (5.4) to enable KVM,so now my system sounds like 
this :

$ lsb_release -a

No LSB modules are available.
Distributor ID: Debian
Description:    Debian GNU/Linux 12 (bookworm)
Release:        12
Codename:       bookworm

$ uname -a
Linux chromarietto 5.4.244-stb-cbe
#8 SMP PREEMPT Sat Aug 19 22:19:32 UTC 2023 armv7l GNU/Linux

$ uname -r
5.4.244-stb-cbe

$ kvm-ok
INFO: /dev/kvm exists
KVM acceleration can be used

$ qemu-system-arm --version
QEMU emulator version 5.1.0 (v5.1.0-dirty)
Copyright (c) 2003-2020 Fabrice Bellard and the QEMU Project developers

$ python3 --version
Python 3.11.2


I have installed libvirt 9.7.0,qemu 5.1 and virt-manager from source 
code with the final goal to be able to connect qemu,kvm and libvirt 
together to virtualize FreeBSD 13.2 for arm 32 bit. 

Some useful informations about my platform :

root@chromarietto:/home/marietto/Desktop# virt-host-validate


QEMU: Checking if device /dev/kvm exists                                  : PASS
QEMU: Checking if device /dev/kvm is accessible                           : PASS
QEMU: Checking if device /dev/vhost-net exists                            : PASS
QEMU: Checking if device /dev/net/tun exists                              : PASS
QEMU: Checking for cgroup 'cpu' controller support                        : PASS
QEMU: Checking for cgroup 'cpuacct' controller support                    : PASS
QEMU: Checking for cgroup 'cpuset' controller support                     : PASS
QEMU: Checking for cgroup 'memory' controller support                     : PASS
QEMU: Checking for cgroup 'devices' controller support                    : PASS
QEMU: Checking for cgroup 'blkio' controller support                      : PASS

QEMU: Checking for device assignment IOMMU support                        : WARN 
(No ACPI IORT table found, IOMMU not supported by this hardware platform)

QEMU: Checking for secure guest support                                   : WARN 
(Unknown if this platform has Secure Guest support)

LXC: Checking for Linux >= 2.6.26                                         : PASS
LXC: Checking for namespace ipc                                           : PASS
LXC: Checking for namespace mnt                                           : PASS
LXC: Checking for namespace pid                                           : PASS
LXC: Checking for namespace uts                                           : PASS
LXC: Checking for namespace net                                           : PASS
LXC: Checking for namespace user                                          : PASS
LXC: Checking for cgroup 'cpu' controller support                         : PASS
LXC: Checking for cgroup 'cpuacct' controller support                     : PASS
LXC: Checking for cgroup 'cpuset' controller support                      : PASS
LXC: Checking for cgroup 'memory' controller support                      : PASS
LXC: Checking for cgroup 'devices' controller support                     : PASS

LXC: Checking for cgroup 'freezer' controller support                     : FAIL
(Enable 'freezer' in kernel Kconfig file or mount/enable cgroup controller in your system)

LXC: Checking for cgroup 'blkio' controller support                       : PASS
LXC: Checking if device /sys/fs/fuse/connections exists                   : PASS


# lsmod | grep kvm
no errors (I have embedded the options needed to enable KVM inside the kernel)

# virsh --connect qemu:///system capabilities | grep baselabel

<baselabel type='kvm'>+1002:+1002</baselabel>
<baselabel type='qemu'>+1002:+1002</baselabel>

The error that I'm not able to fix is the following one :


root@chromarietto:~#  virsh domcapabilities --machine virt --emulatorbin /usr/local/bin/qemu-system-arm

2023-08-29 10:17:59.110+0000: 1763: error : virHostCPUGetKVMMaxVCPUs:1228 : 
KVM is not supported on this platform: Function not implemented ; 
error: failed to get emulator capabilities
error: KVM is not supported on this platform: Function not implemented


and this is the log that I've got when I ran libvirtd with the debug option enabled 

root@chromarietto:~# libvirtd --debug

[Tue, 29 Aug 2023 10:10:11 virt-manager 2141] DEBUG (createvm:494) UEFI found, setting it as default.
[Tue, 29 Aug 2023 10:10:11 virt-manager 2141] DEBUG (createvm:728) Guest type set to os_type=hvm, arch=armv7l, dom_type=kvm
[Tue, 29 Aug 2023 10:10:11 virt-manager 2141] DEBUG (guest:546) Prefer EFI => True
2023-08-29 10:10:12.972+0000: 1765: error : virHostCPUGetKVMMaxVCPUs:1228 : KVM is not supported on this platform: Function not implemented
[Tue, 29 Aug 2023 10:10:12 virt-manager 2141] DEBUG (domcapabilities:250) Error fetching domcapabilities XML
Traceback (most recent call last):
  File "/usr/local/share/virt-manager/virtinst/domcapabilities.py", line 245, in build_from_params
    xml = conn.getDomainCapabilities(emulator, arch,
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/libvirt.py", line 4612, in getDomainCapabilities
    raise libvirtError('virConnectGetDomainCapabilities() failed')
libvirt.libvirtError: KVM is not supported on this platform: Function not implemented