[libvirt-users] virsh -c lxc:/// setvcpus and <vcpu> configuration fails

[info at layer7.net]

Hi folks!

i created a server with this XML file:

<domain type='lxc'>
  <name>lxctest1</name>
  <uuid>227bd347-dd1d-4bfd-81e1-01052e91ffe2</uuid>
  <metadata>
    <libosinfo:libosinfo
xmlns:libosinfo="http://libosinfo.org/xmlns/libvirt/domain/1.0">
      <libosinfo:os id="http://centos.org/centos/6.9"/>
    </libosinfo:libosinfo>
  </metadata>
  <memory unit='KiB'>1024000</memory>
  <currentMemory unit='KiB'>1024000</currentMemory>
 <vcpu>2</vcpu>
  <numatune>
    <memory mode='strict' placement='auto'/>
  </numatune>
  <resource>
    <partition>/machine</partition>
  </resource>
  <os>
    <type arch='x86_64'>exe</type>
    <init>/sbin/init</init>
  </os>
  <idmap>
    <uid start='0' target='200000' count='65535'/>
    <gid start='0' target='200000' count='65535'/>
  </idmap>
  <features>
    <privnet/>
  </features>
  <clock offset='utc'/>
  <on_poweroff>destroy</on_poweroff>
  <on_reboot>restart</on_reboot>
  <on_crash>destroy</on_crash>
  <devices>
    <emulator>/usr/libexec/libvirt_lxc</emulator>
    <filesystem type='mount' accessmode='mapped'>
      <source dir='/mnt'/>
      <target dir='/'/>
    </filesystem>
    <interface type='network'>
      <mac address='00:16:3e:3e:3e:bb'/>
      <source network='Public Network'/>
    </interface>
    <console type='pty'>
      <target type='lxc' port='0'/>
    </console>
  </devices>
</domain>


I would expect it to have 2 cpu cores and 1 GB RAM.


The RAM config works.
The CPU config does not:


[root at lxctest1 ~]# lscpu
Architecture:          x86_64
CPU op-mode(s):        32-bit, 64-bit
Byte Order:            Little Endian
CPU(s):                24
On-line CPU(s) list:   0-23
Thread(s) per core:    2
Core(s) per socket:    6
Socket(s):             2
NUMA node(s):          2
Vendor ID:             GenuineIntel
CPU family:            6
Model:                 62
Model name:            Intel(R) Xeon(R) CPU E5-2620 v2 @ 2.10GHz
Stepping:              4
CPU MHz:               2399.950
BogoMIPS:              4205.88
Virtualization:        VT-x
L1d cache:             32K
L1i cache:             32K
L2 cache:              256K
L3 cache:              15360K
NUMA node0 CPU(s):     0,2,4,6,8,10,12,14,16,18,20,22
NUMA node1 CPU(s):     1,3,5,7,9,11,13,15,17,19,21,23


It gives me all CPU's from the host.

I also tried it with

<cpu>
  <topology sockets='1' cores='2' threads='1'/>
</cpu>

That didnt help too.

I tried to modify the vcpus through virsh:



#virsh -c lxc:/// setvcpus lxctest1 2

error: this function is not supported by the connection driver:
virDomainSetVcpus

Which didnt work too.


This happens on:

Centos 7
Kernel: 5.1.15-1.el7.elrepo.x86_64

#virsh -V
Virsh command line tool of libvirt 4.5.0
See web site at https://libvirt.org/

Compiled with support for:
 Hypervisors: QEMU/KVM LXC ESX Test
 Networking: Remote Network Bridging Interface netcf Nwfilter VirtualPort
 Storage: Dir Disk Filesystem SCSI Multipath iSCSI LVM RBD Gluster ZFS
 Miscellaneous: Daemon Nodedev SELinux Secrets Debug DTrace Readline


and also on

Fedora 30
Kernel: 5.2.9-200.fc30.x86_64

# virsh -V
Virsh command line tool of libvirt 5.1.0
See web site at https://libvirt.org/

Compiled with support for:
 Hypervisors: QEMU/KVM LXC LibXL OpenVZ VMware PHYP VirtualBox ESX
Hyper-V Test
 Networking: Remote Network Bridging Interface netcf Nwfilter VirtualPort
 Storage: Dir Disk Filesystem SCSI Multipath iSCSI LVM RBD Sheepdog
Gluster ZFS
 Miscellaneous: Daemon Nodedev SELinux Secrets Debug DTrace Readline


-----------

Can anyone please tell me what i am doing wrong here ?

Thank you !

Greetings
Oliver